Safety blood collection assembly with indicator

CROSS REFERENCE TO RELATED APPLICATIONS

0001The present application claims priority to <patcit id="pcit0001" dnum="US94187007P"><text>United States Provisional Application Serial No. 60/941,870 filed June 4, 2007</text></patcit>, and <patcit id="pcit0002" dnum="US89351907P"><text>United States Provisional Application Serial No. 60/893,519 filed March 7, 2007</text></patcit>, the entire disclosure of each application is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

0002The present invention relates generally to shieldable safety needle assemblies and, more particularly, to needle assemblies having a housing, a needle cannula, and a shield restrainably engaged with a portion of the housing.

Description of Related Art

0003Typical needle assemblies include a needle cannula having a proximal end, a pointed distal end with a puncture tip, and a lumen extending therebetween. A thermoplastic hub is often mounted securely to the needle cannula at a location spaced apart from the distal end. The hub is typically provided with external threads or other surface configurations for mounting the needle cannula to another structure. Some needle assemblies are used for drawing a specimen, such as a sample of blood or other bodily fluid, from a patient.

0004A needle assembly that is used to draw a sample of blood or other bodily fluid is typically used in association with a housing. Needle cannulae used in association with these assemblies typically have pointed proximal and distal ends, and the needle hub is mounted to a location between the opposed ends of the needle cannula. The housing typically includes a substantially tubular sidewall with a widely opened proximal end, and a partly closed distal end. The hub of the prior art needle assembly can be engaged with the partly closed distal end of the needle holder. Thus, the pointed proximal end of the needle cannula projects into the needle holder for engagement with an evacuated tube, while the pointed distal end of the needle cannula projects distally beyond the needle holder for puncturing the patient's skin.

0005The needle assembly is often used with a specimen collection tube for drawing a sample of blood or other bodily fluid from a patient. The specimen collection tube typically includes a closed end, an open end, and a sidewall extending therebetween. The tube is typically evacuated, and the open end is sealed by a septum that retains the vacuum within the tube. The evacuated tube is dimensioned to be slid into the open proximal end of the needle holder. Sufficient sliding of the evacuated tube into the needle holder causes the proximal point of the needle cannula to pierce the septum of the evacuated tube. Thus, the needle cannula can be placed in communication with the interior of the evacuated tube.

0006The combined needle assembly and evacuated tube is employed by initially urging the pointed distal end of the needle cannula into a blood vessel of a patient. Once the targeted blood vessel has been accessed, the evacuated tube is urged into the needle holder such that the proximal point of the needle cannula pierces the septum of the tube. Low pressure conditions within the evacuated tube, as well as the patient's own vasculature pressure, generate a flow of blood from the patient through the needle cannula and into the evacuated tube. The evacuated tube may be removed from the needle holder after a sufficient quantity of blood has been collected. One or more additional evacuated tubes may similarly be urged into the open end of the needle holder for drawing one or more additional samples of blood to be analyzed. The needle cannula is then withdrawn from the patient after a sufficient volume of blood has been collected for the required analytical procedure. In order to reduce the risk of an accidental needle stick, or contact that could transmit pathogens from the patient to the medical practitioner, the needle cannula must be properly shielded after contact with the patient.

0007Many types of devices are available for shielding a used needle cannula. Example shielding devices include those disclosed in <patcit id="pcit0003" dnum="US5348544A"><text>United States Patent Nos. 5,348,544</text></patcit>; <patcit id="pcit0004" dnum="US5242417A"><text>5,242,417</text></patcit>; <patcit id="pcit0005" dnum="US6592556B"><text>6,592,556</text></patcit>; <patcit id="pcit0006" dnum="US6635032B"><text>6,635,032</text></patcit>; and <patcit id="pcit0007" dnum="US7001363B"><text>7,001,363</text></patcit>, the entire disclosures of which are herein incorporated by reference. Most shielded needle assemblies are effective at performing their primary function, i.e., shielding a used needle cannula. However, many medical practitioners consider the available shieldable needle assemblies cumbersome. Additionally, in some cases, practitioners may be rushing and forget to operate the safety shield. Other situations arise where the patient moves suddenly or unexpectedly. Thus, the needle cannula may inadvertently be pulled out of the vein and exposed with no time for the phlebotomist to initiate safety shielding.

0008Another problem with many prior art blood collection devices relates to the time required to assure venous entry. In particular, blood will begin to flow through the cannula upon entry of the intravenous or distal end of the cannula into the vein. However, air present in the cannula, and in the multiple sample sleeve that covers the non-patient end of the cannula, will resist the flow of blood into and through the cannula. In response, the medical practitioner will typically urge an evacuated tube into the needle holder once the practitioner is reasonably sure that the vein has been entered. The rubber stopper at the end of the evacuated tube will deform the multiple sample sleeve over the non-patient end of the cannula and will permit the non-patient end of the cannula to enter the evacuated tube. The pressure differential between the evacuated tube and the cannula will cause the blood to flow into the evacuated tube. In conventional needle assemblies, this often provides the first visual assurance that the vein has been accessed properly.

0009However, there are many instances in which a medical practitioner will properly access a vein with the distal end of the needle cannula, but will mistakenly believe that the vein has not been entered. Hence, the practitioner will make a second attempt to access the vein. This adds to the discomfort for the patient, extends the time required to carry out a blood collection procedure, and increases the risk for accidental contact between the medical practitioner and a cannula that has been exposed to the patient's blood. Additionally, in some instances a passive shielding mechanism will be activated when the cannula is withdrawn from the patient, thereby making the needle cannula unusable and requiring the medical practitioner to obtain a new needle assembly.

SUMMARY OF THE INVENTION

0010A need continues to exist for safety needle assemblies incorporating both a visual flash indicator and a safety shield that can be transitioned from a retracted position in which the tip of a needle cannula is exposed, to an extended position in which the tip of the needle cannula is shielded, which minimizes the risk of exposure to medical personnel, is convenient to use, and is cost-effective.

0011In one embodiment of the present application, a needle assembly includes a housing having a flash chamber, the housing having a distal end and a proximal end engageable with a specimen collection container. The needle assembly includes a cannula having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior. The patient end of the cannula projects at least partially from the distal end of the housing, and the cannula interior in fluid communication with the flash chamber. The needle assembly also includes a shield restrainably engaged with a portion of the housing. The shield is axially transitionable over the patient cannula from a retracted position in which the patient end is exposed, to an extended position in which the patient end is shielded by at least a portion of the shield. At least a portion of the flash chamber is visible in the retracted position.

0012The flash chamber may be visible through at least a portion of the shield in the retracted position. In one configuration, the portion of the shield through which the flash chamber is visible is transparent or translucent. In another configuration, the shield includes an observation window, and the flash chamber is visible through the observation window in the retracted position. The patient end of the cannula may include a bevel, and the position of the observation window within the shield may correspond to the orientation of the bevel.

0013In one configuration, the proximal end of the housing defines a specimen collection container receiving port. A removable seal may be disposed over a portion of the specimen collection container receiving port. Alternatively, a rupturable seal may be disposed over a portion of the specimen collection container receiving port.

0014The shield may at least partially surround the patient end of the cannula in the extended position. Optionally, the shield is substantially circumferentially disposed about at least a portion of the cannula, and transition of the shield from the retracted position to the extended position telescopes the shield over the cannula. In certain embodiments, the sidewall of the cannula defines an opening extending between the cannula interior and the flash chamber. In other embodiments, the cannula includes at least two distinct needle portions, such as a patient needle in fluid communication with the flash chamber, and a non-patient needle in fluid communication with the flash chamber. The patient needle may project at least partially from the distal end of the housing, and the non-patient needle may extend in a substantially proximal direction from the patient cannula. In one embodiment, the specimen collection container engageable at the proximal end of the housing is a blood collection container.

0015The flash chamber may be integrally formed within a portion of the housing. In certain configurations, the housing includes a hub supporting at least a portion of the cannula, and the flash chamber is integrally formed with the hub. A porous vent may be disposed within the flash chamber such that the porous vent separates the flash chamber into a first chamber and a second chamber. The first chamber and the second chamber may be configured such that upon insertion of the patient end of the cannula into a patient, blood flows through the cannula and into the first chamber without sealing the porous vent. Upon application of an evacuated specimen collection container to the non-patient end of the cannula, blood may be drawn from the first chamber and air may be drawn from the second chamber, thereby establishing a negative pressure within the second chamber with respect to an external environment of the flash chamber. Alternatively, the flash chamber may include a vent mechanism in communication with an environment surrounding the needle assembly. The porous vent may include a plurality of pores for passage of blood therethrough from the first chamber to the second chamber. The vent mechanism may be a porous plug formed of a hydrophobic material, a one-way valve, or a porous plug formed of a hydrophilic material that swells on contact with blood.

0016The shielding portion of the shield may be restrainably engaged within an interior portion of the housing in the retracted position, and the shielding portion of the shield may extend from the interior portion of the housing in the extended position. The interior portion of the housing may be circumferentially disposed about a specimen collection container receiving port defined within the housing, and the interior portion of the housing may be co-axial with the specimen collection container receiving port.

0017Optionally, the housing may include a first portion and a second portion, with the first portion distal to the second portion. The shield may be entirely disposed within an interior of the first portion in the retracted position, and a specimen collection container receiving port may be defined within the second portion. The first portion and the second portion of the housing may be co-formed. Alternatively, the first portion and the second portion of the housing may be separately formed and subsequently assembled. The first portion of the housing may define an observation window through which the shield is visible when in the retracted position.

0018In certain configurations, the shield may be biased against a portion of the housing by a spring when the shield is in the retracted position. The needle assembly may also include a release element transitionable from a first position to a second position, wherein the spring biases the shield to the extended position upon transition of the release element from the first position to the second position. The release element may be a push button. Optionally, the push button includes a member oriented in a substantially perpendicular orientation with respect to a transition axis of the shield. The member may also extend through at least a portion of the shield to maintain the shield against the bias of the spring in the first position. The member may also include a restraining portion and may define a passage region. The restraining portion may engage a shoulder of the shield in the restrained position, and the shoulder of the shield may pass through the passage region upon transition from the retracted position to the extended position. In one configuration, the passage region defines a substantially circular opening. Alternatively, the passage region defines a non-enclosed region. The needle assembly may also include a hub supporting at least a portion of the cannula, and the member of the push button may define an interior region at least partially surrounding a portion of the hub.

0019In another configuration, the needle assembly may also include a removable cannula guard engageable with a portion of the housing, and removable prior to transition of the shield from the retracted position to the extended position. A portion of the removable cannula guard may prevent transition of the release element from the first position to the second position. In another configuration, at least one of a distal portion of the housing and a proximal portion of the shield may include a barrier mechanism for preventing transition of the shield from the extended position to the retracted position. The barrier mechanism may include a tamper-resistant flange. The barrier mechanism may also include a locking tab deflectable upon transition of the shield from the retracted position to the extended position, which substantially resists deflection once the shield is in the extended position. A portion of the housing may surround at least a portion of the locking tab. The portion of the housing surrounding the locking tab may substantially resist deflection of the locking tab.

0020The shield of the needle assembly may include a first portion for slideably engaging a portion of the housing along a longitudinal axis of the cannula, and a second portion at least partially surrounding a portion of the cannula in the extended position. The first portion of the shield may slideably engage an outer surface of the housing. In one configuration, the first portion of the shield includes a protrusion for slideably engaging a groove recessed within a portion of the outer surface of the housing. In another configuration, a glide mechanism includes a portion of the housing and portion of the first portion of the shield, wherein a portion of the safety shield is axially transitionable with respect to a portion of the housing.

0021The needle assembly may also include a hub disposed at least partially within a portion of the housing, such that the first portion of the shield slideably engages a portion of the hub along a longitudinal axis of the cannula. A first end of the first portion of the shield may slideably engage a portion of the hub, and a second end of the first portion may extend at least partially through a portion of an outer surface of the housing. The second end of the first portion may extend at least partially through a groove defined in the outer surface of the housing and extending along the longitudinal axis of the cannula. In another configuration, the second portion of the shield may surround at least a portion of the cannula.

0022The shield of the needle assembly may be transitioned from the retracted position to the extended position by force applied to the first portion of the shield in the direction along a longitudinal axis of the cannula. The second portion of the shield may also include restraining means for preventing transition of the shield from the extended position to the retracted position.

0023In one configuration, the second portion of the shield includes a depending arm transitionable from a first position in which the depending arm is substantially perpendicular to a longitudinal axis of the cannula, to a second position in which the depending arm is oriented substantially along the longitudinal axis of the cannula. The depending arm may include a first portion and a second portion, with the first portion and the second portion pivotally or hingedly connected to the first portion. The shield may include a depending arm, including a plurality of extendable segments, wherein the extendable segments are substantially laterally oriented in the retracted position and substantially longitudinally oriented in the extended position. The plurality of extendable segments may be pivotally or hingedly connected therebetween. The depending arm may be oriented on a first side of the cannula, and a second depending arm may be oriented on a second side of the cannula, with the second side being substantially opposite the first side.

0024In another embodiment of the present invention, a blood collection assembly includes a housing including a flash chamber, the housing having a distal end and a proximal end, and a blood collection container holder adjacent the proximal end. The blood collection assembly includes a patient cannula having a cannula tip and defining a patient cannula interior. The patient cannula projecting at least partially from the distal end of the housing, and the patient cannula interior is in fluid communication with the flash chamber. The blood collection assembly also includes a non-patient cannula, defining a non-patient cannula interior, extending in a substantially proximal direction from the patient cannula within at least a portion of the blood collection container holder. The non-patient cannula interior is in fluid communication with the flash chamber. The blood collection assembly also includes a shield restrainably engaged with a portion of the housing. The shield is axially transitionable over the patient cannula from a retracted position in which the patient end is exposed, to an extended position in which the cannula tip is shielded by at least a portion of the shield. At least a portion of the flash chamber is visible in the retracted position.

0025The flash chamber may be visible through at least a portion of the shield in the retracted position. The blood collection assembly may further include a removable or rupturable seal disposed over at least a portion of the blood collection container holder. In one configuration, the shield may be biased against a portion of the housing by a spring in the retracted position. The blood collection assembly may further include a release element transitionable from a first position to a second position, wherein the spring transitions the shield to the extended position upon transition of the release element from the first position to the second position. The shield may also include a first portion for slideably engaging a portion of the housing along the longitudinal axis of the patient cannula, and a second portion at least partially surrounding a portion of the patient cannula in the extended position.

0026In yet another embodiment of the present invention, a needle assembly includes a housing having a flash chamber, the housing having a distal end, and a proximal end engageable with a specimen collection container. The needle assembly includes a cannula, having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior. The patient end of the cannula projects at least partially from the distal end of the housing, and the cannula interior is in fluid communication with the flash chamber. The needle assembly also includes a shield restrainably engaged with a portion of the housing. The shield is axially transitionable over the patient cannula from a retracted position in which the patient end is exposed, to an extended position in which the patient end is shielded by at least a portion of the shield. At least a portion of the flash chamber is visible in the retracted position. The needle assembly also includes a spring element biased between a portion of the housing and a portion of the shield in the retracted position. The needle assembly further includes a release element transitionable from a first position to a second position. The release element restrains the shield against the bias of the spring in the restrained position, and transition of the release element from the first position to the second position transitions the shield from the retracted position to the extended position.

0027The release element may be a push button. In certain configurations, at least a portion of the flash chamber is visible through a portion of the shield in the retracted position. In other configurations, the proximal end of the housing includes a blood collection container holder, and the non-patient end of the cannula extends at least partially within an interior of the blood collection container holder.

0028In another embodiment of the present invention, a blood collection assembly includes a housing having a flash chamber, the housing having a distal end and a proximal end, and a blood collection container holder adjacent the proximal end. The blood collection assembly includes a patient cannula having a cannula tip and defining a patient cannula interior. The patient cannula projects at least partially from the distal end of the housing, and the patient cannula interior is in fluid communication with the flash chamber. The blood collection assembly also includes a non-patient cannula, defining a non-patient cannula interior. The non-patient cannula extends in a substantially proximal direction from the patient cannula within at least a portion of the blood collection container holder. The non-patient cannula interior is in fluid communication with the flash chamber. The blood collection assembly also includes a shield restrainably engaged with a portion of the housing. The shield is axially transitionable over the patient cannula from a retracted position in which the cannula tip is exposed, to an extended position in which the cannula tip is shielded by at least a portion of the shield. At least a portion of the flash chamber is visible through the shield in the retracted position. The blood collection assembly also includes a spring element biased between a portion of the shield and a portion of the housing in the retracted position. The blood collection assembly further includes a push button engaged with a portion of the spring, and transitionable from a first position to a second position. The spring transitions the shield to the extended position upon transition of the release element from the first position to the second position.

0029In yet another embodiment of the present invention, a blood collection assembly includes a housing having a flash chamber, the housing having a distal end, and a proximal end engageable with a specimen collection container. The blood collection assembly includes a cannula having a patient end; a non-patient end, and a sidewall extending therebetween defining a cannula interior. The patient end of the cannula projects at least partially from the distal end of the housing, and the cannula interior is in fluid communication with the flash chamber. The blood collection assembly also includes a shield, having an observation window, and engaged with a portion of the housing. The shield is transitionable from a first position to a second position with respect to the housing, wherein the shield is disposed over the patient end in the second position, and wherein at least a portion of the flash chamber is viewable through the observation window in the first position.

0030The shield may be axially transitionable over the cannula from a retracted position to an extended position. Alternatively, the shield may be pivotally transitionable over the patient cannula from a retracted position to an extended position.

0031In yet another embodiment of the present invention, a blood collection assembly include a housing having a flash chamber, the housing having a distal end, and a proximate end engageable with a specimen collection container. The blood collection assembly includes a cannula having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior. The patient end of the cannula projects at least partially from the distal end of the housing, and the cannula interior is in fluid communication with the flash chamber. The blood collection assembly also includes a shield engaged with a portion of the housing. The shield is transitionable from a first position to a second position with respect to the housing. The flash chamber is visible in the first position, and the shield is disposed over the patient end of the cannula in the second position. The locking structure engages at least a portion of the flash chamber in the second position. In one configuration, the locking structure of the shield engages a portion of the housing distal to the flash chamber.

0032In one embodiment, the housing of a needle assembly includes a base portion having a sidewall defining an opening, and a hub portion engageable with the base portion. A portion of the hub portion may be receivable through the opening. In another configuration, the sidewall of the base portion defines a first opening and a second opening aligned along a common axis. The hub portion may include a first portion and a second portion aligned along a common axis. The first portion may be receivable through the first opening and the second portion is receivable through the second opening. In yet another configuration, the hub portion may be insertable within an interior of the base portion through a proximal end of the base portion. At least one of the first portion and the second portion may be deflectable against a portion of an interior wall of the base portion during insertion of the hub portion into the base portion.

0033In another embodiment, the housing of a needle assembly may include a forward hub portion and a rear hub portion connectable with the forward hub portion, and defining the flash chamber therebetween. The rear hub portion may be connectable with the forward hub portion through at least a portion of a specimen collection container holder. Alternatively, the rear hub portion may define a specimen collection container receiving port therein.

DESCRIPTION OF THE DRAWINGS

0034<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001"><b>FIG. 1</b></figref> is a perspective view of a needle assembly having a safety shield in the retracted position in accordance with an embodiment of the present invention.</li><li><figref idref="f0001"><b>FIG. 2</b></figref> is a perspective view of the needle assembly of <figref idref="f0001"><b>FIG. 1</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0002"><b>FIG. 3</b></figref> is an enlarged perspective view of the push button element of a needle assembly in accordance with an embodiment of the invention.</li><li><figref idref="f0002"><b>FIG. 4</b></figref> is an enlarged perspective view taken from section <b>4</b> of <figref idref="f0001"><b>FIG. 2</b></figref><b>,</b> showing the channel of the safety shield in accordance with an embodiment of the invention.</li><li><figref idref="f0003"><b>FIG. 5</b></figref> is a side view of the needle assembly of <figref idref="f0001"><b>FIG. 1</b></figref> having a safety shield in the retracted position.</li><li><figref idref="f0003"><b>FIG. 6</b></figref> is a side view of the needle assembly of <figref idref="f0001"><b>FIG. 2</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0004"><b>FIG. 7</b></figref> is a side cross-sectional view of the needle assembly of <figref idref="f0001"><b>FIG. 1</b></figref> having a safety shield in the retracted position.</li><li><figref idref="f0004"><b>FIG. 8</b></figref> is a side cross-sectional view of the needle assembly of <figref idref="f0001"><b>FIG. 2</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0005"><b>FIG. 9</b></figref> is a top cross-sectional view of the needle assembly of <figref idref="f0001"><b>FIG. 1</b></figref> having a safety shield in the retracted position and showing a locking mechanism in accordance with an embodiment of the present invention.</li><li><figref idref="f0005"><b>FIG. 10</b></figref> is a top cross-sectional view of the needle assembly of <figref idref="f0001"><b>FIG. 2</b></figref> having a safety shield in the extended position and showing a locking mechanism.</li><li><figref idref="f0006"><b>FIG. 11</b></figref> is a perspective view of a needle assembly having a flash chamber in accordance with a further embodiment of the present invention.</li><li><figref idref="f0006"><b>FIG. 12</b></figref> is a rear perspective view of the needle assembly having a flash chamber of <figref idref="f0006"><b>FIG. 11</b></figref><b>.</b></li><li><figref idref="f0007"><b>FIG. 13</b></figref> is an exploded view of the needle assembly having a flash chamber of <figref idref="f0006">FIG. 11</figref>.</li><li><figref idref="f0008"><b>FIG. 14A</b></figref> is a cross-sectional view of the needle assembly having a flash chamber of <figref idref="f0006"><b>FIG. 11</b></figref><b>.</b></li><li><figref idref="f0008"><b>FIG. 14B</b></figref> is an enlarged cross-sectional view of a portion of the needle assembly of <figref idref="f0008">FIG. <b>14A</b></figref><b>.</b></li><li><figref idref="f0009"><b>FIG. 15A</b></figref> is a cross-sectional view of a needle assembly having a flash chamber used in connection with a blood collection assembly in yet a further embodiment.</li><li><figref idref="f0010"><b>FIG. 15B</b></figref> is an enlarged sectional view of a portion of the needle assembly of <figref idref="f0009"><b>FIG. 15A</b></figref>.</li><li><figref idref="f0011"><b>FIG. 16</b></figref> is a perspective view of a needle assembly having a safety shield in the retracted position and a needle cover in accordance with an embodiment of the present invention.</li><li><figref idref="f0011"><b>FIG. 17</b></figref> is a perspective view of the needle assembly of <figref idref="f0011"><b>FIG. 16</b></figref> with the needle cover removed and having a safety shield in the extended position.</li><li><figref idref="f0012"><b>FIG. 18</b></figref> is a side view of the needle assembly of <figref idref="f0011"><b>FIG. 16</b></figref> having a safety shield in the retracted position and with a needle cover.</li><li><figref idref="f0012"><b>FIG. 19</b></figref> is a side view of the needle assembly of <figref idref="f0011"><b>FIG. 17</b></figref> with the needle cover removed and having a safety shield in the extended position.</li><li><figref idref="f0013"><b>FIG. 20</b></figref> is a side cross-sectional view of the needle assembly of <figref idref="f0011"><b>FIG. 16</b></figref> having a safety shield in the retracted position and with a needle cover.</li><li><figref idref="f0013"><b>FIG. 21</b></figref> is a side cross-sectional view of the needle assembly of <figref idref="f0011"><b>FIG. 17</b></figref> with the needle cover removed and having a safety shield in the extended position.</li><li><figref idref="f0014"><b>FIG. 22</b></figref> is a top cross-sectional view of the needle assembly of <figref idref="f0011"><b>FIG. 16</b></figref> having a safety shield in the retracted position with a needle cover and showing a locking mechanism in accordance with an embodiment of the present invention.</li><li><figref idref="f0014"><b>FIG. 23</b></figref> is a top cross-sectional view of the needle assembly of <figref idref="f0011"><b>FIG. 17</b></figref> with the needle cover removed and having a safety shield in the extended position and showing a locking mechanism.</li><li><figref idref="f0015"><b>FIG. 24</b></figref> is a perspective view of the needle assembly of the present invention, with the safety shield removed for illustration purposes and including a needle cover in accordance with an embodiment of the present invention.</li><li><figref idref="f0015"><b>FIG. 25</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0015"><b>FIG. 24</b></figref><b>.</b></li><li><figref idref="f0016"><b>FIG. 26</b></figref> is a perspective view of the holder portion of the needle assembly of an embodiment of the present invention having the push button in the unengaged retracted position.</li><li><figref idref="f0016"><b>FIG. 27</b></figref> is a perspective view of the holder shown in <figref idref="f0016"><b>FIG. 26</b></figref> having the push button in the engaged extended position.</li><li><figref idref="f0016"><b>FIG. 28</b></figref> is a perspective view of an embodiment of the push button in accordance with the present invention.</li><li><figref idref="f0017"><b>FIG. 29</b></figref> is a perspective view of a needle assembly having a safety shield in the retracted position in accordance with a further embodiment of the present invention.</li><li><figref idref="f0017"><b>FIG. 30</b></figref> is a perspective view of the needle assembly of <figref idref="f0017"><b>FIG. 29</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0018"><b>FIG. 31</b></figref> is a side view of the needle assembly of <figref idref="f0017"><b>FIG. 29</b></figref> having a safety shield in the retracted position.</li><li><figref idref="f0018"><b>FIG. 32</b></figref> is a side view of the needle assembly of <figref idref="f0017"><b>FIG. 30</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0019"><b>FIG. 33</b></figref> is a top-down cross-sectional view of the needle assembly of <figref idref="f0017"><b>FIG. 29</b></figref> having a safety shield in the retracted position.</li><li><figref idref="f0019"><b>FIG. 34</b></figref> is a top-down cross-sectional view of the needle assembly of <figref idref="f0017"><b>FIG. 30</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0020"><b>FIG. 35</b></figref> is a perspective view of <figref idref="f0017"><b>FIG. 29</b></figref> showing the front-section of a portion of the needle holder.</li><li><figref idref="f0021"><b>FIG. 36</b></figref> is a perspective view of the push button of the needle assembly shown in <figref idref="f0017"><b>FIG. 29</b></figref><b>.</b></li><li><figref idref="f0021"><b>FIG. 37</b></figref> is a perspective view of the needle assembly of <figref idref="f0017"><b>FIG. 29</b></figref> having a needle shield in accordance with an embodiment of the present invention.</li><li><figref idref="f0022"><b>FIG. 38</b></figref> is a cross-sectional view of the needle assembly shown in <figref idref="f0017"><b>FIG. 29</b></figref> having a removable cannula guard disposed thereon.</li><li><figref idref="f0023"><b>FIG. 39</b></figref> is a perspective view of a needle assembly with a push button activator having a removable cannula guard covering a safety shield in the retracted position in accordance with an embodiment of the present invention.</li><li><figref idref="f0023"><b>FIG. 40</b></figref> is a perspective view of the needle assembly of <figref idref="f0023"><b>FIG. 39</b></figref> having the removable cannula guard removed showing the safety shield in the extended position.</li><li><figref idref="f0024"><b>FIG. 41</b></figref> is a side view of the needle assembly of <figref idref="f0023"><b>FIG. 39</b></figref><b>.</b></li><li><figref idref="f0024"><b>FIG. 42</b></figref> is a side view of the needle assembly of <figref idref="f0023"><b>FIG. 40</b></figref><b>.</b></li><li><figref idref="f0025"><b>FIG. 43</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0023"><b>FIG. 39</b></figref><b>.</b></li><li><figref idref="f0025"><b>FIG. 44</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0023"><b>FIG. 40</b></figref><b>.</b></li><li><figref idref="f0026"><b>FIG. 45</b></figref> is a top view of the needle assembly of <figref idref="f0023"><b>FIG. 39</b></figref><b>.</b></li><li><figref idref="f0026"><b>FIG. 46</b></figref> is a top view of the needle assembly of <figref idref="f0023"><b>FIG. 40</b></figref><b>.</b></li><li><figref idref="f0027"><b>FIG. 47</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0023"><b>FIG. 39</b></figref><b>.</b></li><li><figref idref="f0027"><b>FIG. 48</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0023"><b>FIG. 40</b></figref><b>.</b></li><li><figref idref="f0028"><b>FIG. 49</b></figref> is a close-up cross-section view of the needle assembly of <figref idref="f0027"><b>FIG. 47</b></figref><b>.</b></li><li><figref idref="f0029"><b>FIG. 50</b></figref> is an exploded perspective view of the needle assembly of <figref idref="f0023"><b>FIG. 39</b></figref><b>.</b></li><li><figref idref="f0030"><b>FIG. 51</b></figref> is a partial perspective side view of a loclting tab in accordance with an embodiment of the present invention.</li><li><figref idref="f0030"><b>FIG. 52</b></figref> is a partial perspective side view of the locking tab of <figref idref="f0030"><b>FIG. 51</b></figref> partially engaged with a housing in accordance with an embodiment of the present invention.</li><li><figref idref="f0031"><b>FIG. 53</b></figref> is an exploded perspective view of a needle assembly in accordance with an embodiment of the present invention.</li><li><figref idref="f0032"><b>FIG. 54</b></figref> is a partially assembled perspective view of the needle assembly of <figref idref="f0031"><b>FIG. 53</b></figref><b>.</b></li><li><figref idref="f0032"><b>FIG. 55</b></figref> is a partially assembled perspective view of the needle assembly of <figref idref="f0031"><b>FIG. 53</b></figref><b>.</b></li><li><figref idref="f0033"><b>FIG. 56</b></figref> is an alternative exploded perspective view of a needle assembly in accordance with an embodiment of the present invention</li><li><figref idref="f0034"><b>FIG. 57</b></figref> is a partially assembled perspective view of the needle assembly of <figref idref="f0033"><b>FIG. 56</b></figref><b>.</b></li><li><figref idref="f0033"><b>FIG. 58</b></figref> is a partially assembled perspective view of the needle assembly of <figref idref="f0033"><b>FIG. 56</b></figref><b>.</b></li><li><figref idref="f0035"><b>FIG. 59</b></figref> is a perspective view of a needle assembly having a distal needle shield, and proximal needle shield in accordance with an embodiment of the present invention.</li><li><figref idref="f0035"><b>FIG. 60</b></figref> is a top view of the hub assembly, distal needle shield, and proximal needle shield of <figref idref="f0035"><b>FIG. 59</b></figref><b>.</b></li><li><figref idref="f0036"><b>FIG. 61</b></figref> is a cross-sectional top view of the needle assembly of <figref idref="f0035"><b>FIG. 60</b></figref><b>.</b></li><li><figref idref="f0036"><b>FIG. 62</b></figref> is a side view of the needle assembly of <figref idref="f0035"><b>FIG. 59</b></figref><b>.</b></li><li><figref idref="f0037"><b>FIG. 63</b></figref> is a cross-sectional view of the side view of <figref idref="f0036"><b>FIG. 62</b></figref><b>.</b></li><li><figref idref="f0037"><b>FIG. 64</b></figref> is a perspective view of the needle assembly of <figref idref="f0035"><b>FIG. 59</b></figref> engaged with a specimen collection container holder in accordance with an embodiment of the present invention.</li><li><figref idref="f0038"><b>FIG. 65</b></figref> is a cross-sectional side view of a needle assembly in the retracted position having an alternative locking mechanism in accordance with an embodiment of the present invention.</li><li><figref idref="f0038"><b>FIG. 66</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0038"><b>FIG. 65</b></figref> in the extended position.</li><li><figref idref="f0039"><b>FIG. 67</b></figref> is a perspective view of a needle assembly having a safety shield in the retracted position and including a glide mechanism in accordance with an embodiment of the present invention.</li><li><figref idref="f0039"><b>FIG. 68</b></figref> is a perspective view of the needle assembly of <figref idref="f0039"><b>FIG. 67</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0040"><b>FIG. 69</b></figref> is a side view of the needle assembly of <figref idref="f0039"><b>FIG. 67</b></figref> having a safety shield in the retracted position.</li><li><figref idref="f0040"><b>FIG. 70</b></figref> is a side view of the needle assembly of <figref idref="f0039"><b>FIG. 68</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0041"><b>FIG. 71</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0040"><b>FIG. 69</b></figref> having a safety shield in the retracted position.</li><li><figref idref="f0041"><b>FIG. 72</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0040"><b>FIG. 70</b></figref> having a safety shield in the extended position.</li><li><figref idref="f0042"><b>FIG. 73</b></figref> is an exploded perspective view of a needle assembly with a glideable safety shield in accordance with an embodiment of the present invention.</li><li><figref idref="f0043"><b>FIG. 74</b></figref> is an exploded perspective view of the needle assembly of <figref idref="f0042"><b>FIG. 73</b></figref><b>.</b></li><li><figref idref="f0044"><b>FIG. 75</b></figref> is a top view of the needle assembly of <figref idref="f0042"><b>FIG. 73</b></figref> in the assembled and retracted position.</li><li><figref idref="f0044"><b>FIG. 76</b></figref> is a cross-sectional top view of the needle assembly of <figref idref="f0044"><b>FIG. 75</b></figref> in the retracted position.</li><li><figref idref="f0045"><b>FIG. 77</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0042"><b>FIG. 73</b></figref> in the assembled and retracted position.</li><li><figref idref="f0045"><b>FIG. 78</b></figref> is a side view of the needle assembly of <figref idref="f0045"><b>FIG. 77</b></figref> in the retracted position.</li><li><figref idref="f0046"><b>FIG. 79</b></figref> is a bottom view of the needle assembly of <figref idref="f0042"><b>FIG. 73</b></figref> in the assembled and retracted position.</li><li><figref idref="f0046"><b>FIG. 80</b></figref> is a front view of the assembled needle assembly of <figref idref="f0042"><b>FIG. 73</b></figref><b>.</b></li><li><figref idref="f0046"><b>FIG. 81</b></figref> is a rear view of the needle assembly of <figref idref="f0046"><b>FIG. 80</b></figref><b>.</b></li><li><figref idref="f0047"><b>FIG. 82</b></figref> is a cross-sectional top view of the needle assembly of <figref idref="f0044"><b>FIG. 76</b></figref> in the extended position.</li><li><figref idref="f0047"><b>FIG. 83</b></figref> is a top view of the needle assembly of <figref idref="f0047"><b>FIG. 82</b></figref> in the extended position.</li><li><figref idref="f0048"><b>FIG. 84</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0045"><b>FIG. 77</b></figref> in the extended position.</li><li><figref idref="f0048"><b>FIG. 85</b></figref> is a side view of the needle assembly of <figref idref="f0045"><b>FIG. 78</b></figref> in the extended position.</li><li><figref idref="f0049"><b>FIG. 86</b></figref> is a bottom view of the needle assembly of <figref idref="f0046"><b>FIG. 79</b></figref> in the extended position.</li><li><figref idref="f0050"><b>FIG. 87</b></figref> is a perspective view of a needle assembly having an articulating hinge safety shield in the retracted position in accordance with an embodiment of the present invention.</li><li><figref idref="f0051 f0052 f0053"><b>FIGS. 88-90</b></figref> are perspective views of the needle assembly of <figref idref="f0050"><b>FIG. 87</b></figref> having an articulating hinge safety shield shown in various stages of partial extension.</li><li><figref idref="f0054"><b>FIG. 91</b></figref> is a perspective view of the needle assembly of <figref idref="f0050"><b>FIG. 87</b></figref> having an articulating hinge safety shield in the fully extended position.</li><li><figref idref="f0055"><b>FIG. 92</b></figref> is a perspective view of a needle assembly having a butterfly hinged safety shield in the retracted position in accordance with an embodiment of the present invention.</li><li><figref idref="f0055"><b>FIG. 93</b></figref> is a perspective view of the needle assembly of <figref idref="f0055"><b>FIG. 92</b></figref> having a butterfly hinged safety shield shown in the extended position.</li><li><figref idref="f0056"><b>FIG. 94</b></figref> is a perspective view of a needle assembly having a hinged safety shield and a needle guard shield in accordance with an embodiment of the present invention.</li><li><figref idref="f0057"><b>FIG. 95</b></figref> is a side view of the needle assembly of <figref idref="f0056"><b>FIG. 94</b></figref><b>.</b></li><li><figref idref="f0058"><b>FIG. 96</b></figref> is a top view of the needle assembly of <figref idref="f0056"><b>FIG. 94</b></figref><b>.</b></li><li><figref idref="f0058"><b>FIG. 97</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0056"><b>FIG. 94</b></figref><b>.</b></li><li><figref idref="f0059"><b>FIG. 98</b></figref> is a perspective view of the needle assembly of <figref idref="f0056"><b>FIG. 94</b></figref> having the needle guard shield removed and in the retracted position.</li><li><figref idref="f0060"><b>FIG. 99</b></figref> is a side view of the needle assembly of <figref idref="f0059"><b>FIG. 98</b></figref><b>.</b></li><li><figref idref="f0061"><b>FIG. 100</b></figref> is a top view of the needle assembly of <figref idref="f0059"><b>FIG. 98</b></figref><b>.</b></li><li><figref idref="f0061"><b>FIG. 101</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0059"><b>FIG. 98</b></figref><b>.</b></li><li><figref idref="f0062"><b>FIG. 102</b></figref> is a perspective view of the needle assembly of <figref idref="f0059"><b>FIG. 98</b></figref> in the extended position.</li><li><figref idref="f0063"><b>FIG. 103</b></figref> is a side view of the needle assembly of <figref idref="f0062"><b>FIG. 102</b></figref><b>.</b></li><li><figref idref="f0063"><b>FIG. 104</b></figref> is a cross-sectional view of the needle assembly of <figref idref="f0062"><b>FIG. 102</b></figref><b>.</b></li><li><figref idref="f0064"><b>FIG. 105</b></figref> is a perspective view of the engagement of the safety shield and the front hub portion in accordance with an embodiment of the present invention.</li><li><figref idref="f0064"><b>FIG. 106</b></figref> is a close-up sectional perspective view of.the engagement between the safety shield and the front hub portion in accordance with an embodiment of the present invention.</li><li><figref idref="f0065"><b>FIG. 107</b></figref> is an exploded perspective view of a needle assembly having a hinged safety shield in accordance with an embodiment of the present invention.</li><li><figref idref="f0066"><b>FIG. 108</b></figref> is an assembled perspective view of the needle assembly of <figref idref="f0065"><b>FIG. 107</b></figref> in the retracted position.</li><li><figref idref="f0067"><b>FIG. 109</b></figref> is a side view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref><b>.</b></li><li><figref idref="f0067"><b>FIG. 110</b></figref> is a top view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref><b>.</b></li><li><figref idref="f0068"><b>FIG. 111</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref><b>.</b></li><li><figref idref="f0069"><b>FIG. 112</b></figref> is a front view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref><b>.</b></li><li><figref idref="f0069"><b>FIG. 113</b></figref> is a rear view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref><b>.</b></li><li><figref idref="f0070"><b>FIG. 114</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref><b>.</b></li><li><figref idref="f0071"><b>FIG. 115</b></figref> is an alternative exploded view of a needle assembly having a hinged safety shield in accordance with an embodiment of the present invention.</li><li><figref idref="f0072"><b>FIG. 116</b></figref> is a perspective view of the needle assembly of <figref idref="f0066"><b>FIG. 108</b></figref> in the extended position.</li><li><figref idref="f0073"><b>FIG. 117</b></figref> is a top view of the needle assembly of <figref idref="f0072"><b>FIG. 116</b></figref> in the extended position.</li><li><figref idref="f0073"><b>FIG. 118</b></figref> is a cross-sectional side view of the needle assembly of <figref idref="f0072"><b>FIG. 116</b></figref><b>.</b></li><li><figref idref="f0074"><b>FIG. 119</b></figref> is a side view of the needle assembly of <figref idref="f0072"><b>FIG. 116</b></figref> in the extended position.</li><li><figref idref="f0075"><b>FIG. 120</b></figref> is a front view of the needle assembly of <figref idref="f0072"><b>FIG. 116</b></figref><b>.</b></li><li><figref idref="f0075"><b>FIG. 121</b></figref> is a rear view of the needle assembly of <figref idref="f0072"><b>FIG. 116</b></figref><b>.</b></li><li><figref idref="f0076"><b>FIG. 122</b></figref> is a sectional perspective view of an alternative hinged safety shield shown in the extended position in accordance with an embodiment of the present invention.</li><li><figref idref="f0077"><b>FIG. 123</b></figref> is a perspective view of a needle assembly having a pierceable seal prior to use with a sample container in accordance with an embodiment of the present invention.</li><li><figref idref="f0077"><b>FIG. 124</b></figref> is a perspective view of the needle assembly of <figref idref="f0077"><b>FIG. 123</b></figref> in use.</li><li><figref idref="f0077"><b>FIG. 125</b></figref> is a perspective view of the needle assembly of <figref idref="f0077"><b>FIG. 124</b></figref> having the container removed from the pierceable seal after use.</li><li><figref idref="f0078"><b>FIG. 126</b></figref> is a perspective view of a base portion of the housing of a needle assembly in accordance with an embodiment of the present invention.</li><li><figref idref="f0078"><b>FIG. 127</b></figref> is a side view of the base portion of <figref idref="f0078"><b>FIG. 126</b></figref><b>.</b></li><li><figref idref="f0079"><b>FIG. 128</b></figref> is a perspective view of a hub portion of the housing of a needle assembly in accordance with an embodiment of the present invention.</li><li><figref idref="f0079"><b>FIG. 129</b></figref> is a side view of the hub portion of <figref idref="f0079"><b>FIG. 128</b></figref><b>.</b></li><li><figref idref="f0080"><b>FIG. 130</b></figref> is a perspective view of an assembled housing of a needle assembly including the base portion of <figref idref="f0078"><b>FIG. 126</b></figref> and the hub portion of <figref idref="f0079"><b>FIG. 128</b></figref><b>.</b></li><li><figref idref="f0081"><b>FIG. 131</b></figref> is a side view of the assembled housing of <figref idref="f0080"><b>FIG. 130</b></figref><b>.</b></li></ul>

DETAILED DESCRIPTION

0035In general, the needle assembly of the present invention allows for access of a patient's vasculature by a needle cannula, visual indication of vasculature access, and subsequent safety shielding of the needle cannula to protect medical practitioners.

0036In one embodiment of the present invention, a needle assembly <b>30</b> is provided, as generally shown in <figref idref="f0001 f0002 f0003 f0004 f0005"><b>FIGS. 1-10</b></figref><b>.</b> The needle assembly <b>30</b> generally includes a housing <b>32</b> having a flash chamber <b>38</b> integral therewith, a cannula <b>34</b> associated with the housing <b>32,</b> and a safety shield <b>36</b> adapted to transition from a retracted position, shown in <figref idref="f0001"><b>FIG. 1</b></figref><b>,</b> to an extended position, shown in <figref idref="f0001"><b>FIG. 2</b></figref><b>,</b> for safety shielding of the cannula <b>34</b> during and/or after use of the needle assembly <b>30.</b> The needle assembly <b>30</b> is shown in the retracted position ready for use in a specimen collection procedure, such as a blood collection procedure, in <figref idref="f0001"><b>FIG. 1</b></figref><b>,</b> and after use in the extended position shielding the cannula in <figref idref="f0001"><b>FIG. 2</b></figref><b>.</b>

0037With particular reference to <figref idref="f0004 f0005"><b>FIGS. 7-10</b></figref><b>,</b> the needle assembly <b>30</b> includes a cannula <b>34</b> having a distal patient end <b>40</b> and a proximal non-patient end <b>42.</b> It will be noted that the term "distal" as used herein, refers generally to the forward end of the needle assembly <b>30</b> that is adapted to puncture the skin of a patient and access the patient's vasculature, while the term "proximal" refers generally to the rear end of the needle assembly <b>30</b> that is engageable with a specimen collection container (shown in <figref idref="f0077"><b>FIG. 123</b></figref>). The cannula <b>34</b> includes a sidewall <b>48</b> extending between the patient end <b>40</b> and the non-patient end <b>42</b> and defining a cannula interior <b>50.</b> In one embodiment, the cannula <b>34</b> may include at least two distinct needles, such as a distal patient needle <b>52</b> and a proximal non-patient needle <b>54,</b> both of which define a common central lumen within the cannula interior <b>50.</b> In a further embodiment, the distal patient needle <b>52</b> is aligned substantially along a common axis with the proximal non-patient needle <b>54</b> and separated from the proximal non-patient needle <b>54</b> by a break <b>56.</b> The proximal non-patient end <b>42</b> of the cannula <b>34</b> is provided for puncturing a specimen collection container (shown in <figref idref="f0077"><b>FIG. 123</b></figref>). In one embodiment, the proximal non-patient end <b>42</b> of the cannula <b>34</b> may be covered by a pierceable elastomeric multiple sample sleeve <b>60.</b> The distal patient end <b>40</b> may have a bevel for allowing easier penetration of a patient's skin.

0038The cannula <b>34</b> of the needle assembly may be at least partially supported by a portion of the housing <b>32.</b> In one embodiment, the housing <b>32</b> may be a hub <b>64</b> for supporting a portion of the cannula <b>34.</b> For example, proximal non-patient needle <b>54</b> and distal patient needle <b>52</b> may be affixed or otherwise adhered within a central opening <b>66</b> of the hub <b>64,</b> with a break <b>56</b> present between proximal non-patient needle <b>54</b> and the distal patient needle <b>52.</b> In another configuration, the hub <b>64</b> may be formed of separate elements. For example, a proximal or rear hub portion <b>68</b> may be connected with or affixed to a forward hub portion <b>70,</b> thereby forming the hub <b>64</b> as a unitary structure, with the cannula <b>34</b> extending therethrough.

0039As shown in <figref idref="f0001"><b>FIGS. 1-2</b></figref> and <b>5-10,</b> the housing <b>32</b> may have a distal end <b>74</b> and a proximal end <b>72</b> engageable with a specimen collection container (shown in <figref idref="f0077"><b>FIG. 123</b></figref>). As used herein, the phrase "engageable with a specimen collection container" means that a specimen collection container may be attached to or affixed with a portion of the proximal end <b>72</b> of the housing <b>32,</b> or that a specimen collection container may be passed within or disposed over or about a portion of the proximal end <b>72</b> of the housing <b>32</b> and secured to another portion of the housing <b>32.</b> In one embodiment, the proximal end <b>72</b> of the needle assembly 30 may define a specimen collection container receiving port 76, adapted to receive a specimen collection container (shown in <figref idref="f0077">FIG. 123</figref>) therewith.

0040In another embodiment, the needle assembly 30 is a specimen collection assembly, such as a blood collection assembly, in which the housing 32 of the needle assembly 30 includes a specimen collection container holder 78 adjacent the proximal end 72 of the needle assembly 30. The specimen collection container holder 78 includes a proximal end 80, a distal end 82, and a tubular sidewall 84 extending therebetween. In one embodiment, the specimen collection container holder 78 may include a second tubular sidewall 86 circumferentially disposed about the tubular sidewall 84. The proximal end 80 of the specimen collection container holder 78 may be substantially open at opening 88 and may be adapted to receive a specimen collection container (shown in <figref idref="f0077"><b>FIG. 123</b></figref>) therein. The proximal end <b>80</b> may also have a radially aligned flange <b>90</b> to facilitate manipulation of the needle assembly <b>30.</b> The flange <b>90</b> may be non-circular to prevent the needle assembly <b>30</b> from rolling, or for other purposes such as communicating to the user the intended orientation of the needle assembly <b>30.</b>

0041The specimen collection container holder <b>78</b> is adapted to accommodate at least a portion of the cannula <b>34</b> in a mating relationship. For example, the distal end <b>82</b> of the specimen collection container holder <b>78</b> may include an engagement portion <b>92</b> to which a portion of the cannula <b>34,</b> such as the non-patient end <b>42</b> is mounted through a portion of the hub <b>64.</b> In particular, the distal end <b>82</b> of the specimen collection container holder <b>78</b> may include an engagement portion <b>92</b> having a mating structure, such as a threaded engagement, adapted to receive the rear hub portion <b>68</b> of the hub <b>64.</b> In one embodiment, the engagement portion <b>92</b> can include threads <b>94</b> for engagement with corresponding threads <b>96</b> of the rear hub portion <b>68</b> of hub <b>64.</b> Other mating relationships are also contemplated herein, such as mating male and female luer assembly components. The hub <b>64</b> may be also adhesively affixed to the engagement portion <b>92</b> of the specimen collection container holder <b>78.</b> In another embodiment, the hub <b>64</b> may be press-fit or snapped into the specimen collection container holder <b>78.</b> Alternatively, hub <b>64</b> may be integrally formed with the distal end <b>82</b> of the specimen collection container holder <b>78,</b> providing a mechanism for direct attachment of the cannula <b>34</b> to the specimen collection container holder <b>78.</b> In certain embodiments, the cannula <b>34</b> is joined with a portion of the specimen collection container holder <b>78</b> by the manufacturer so that the device is ready for fast and convenient use by the medical practitioner.

0042In certain configurations, the patient end <b>40</b> of the cannula <b>34</b> projects at least partially from the distal end <b>74</b> of the housing <b>32,</b> and the non-patient end <b>42</b> extends in a substantially proximal direction from the patient end <b>40.</b> In another embodiment, the distal patient needle <b>52</b> projects at least partially from the distal end <b>74</b> of the housing <b>32,</b> and the proximal non-patient needle <b>54</b> extends in a substantially proximal direction from the patient needle.

0043At least a portion of the housing <b>32,</b> including the hub <b>64,</b> the specimen collection container holder <b>78,</b> and the second tubular sidewall <b>86,</b> includes a flash chamber <b>98.</b> As used herein, the term "flash chamber" includes a cavity into which a specimen, such as blood, from a patient may pass, and through which the presence of the specimen within the cavity may be visibly detected by a medical practitioner. The flash chamber <b>98</b> may be integrally formed with a portion of the housing <b>32</b> or, alternatively, may be separately formed and subsequently engaged with a portion of the housing <b>32.</b> In one embodiment, the cannula interior <b>50</b> is in fluid communication with the flash chamber <b>98.</b> In a further embodiment, the sidewall <b>48</b> of the cannula may define an opening extending between the cannula interior <b>50</b> and the flash chamber <b>98</b> to permit the flow of a specimen, such as blood, from the cannula <b>34</b> to the flash chamber <b>98.</b> In another embodiment, the cannula <b>34</b> includes a distal patient needle <b>52</b> in fluid communication with the flash chamber <b>98,</b> and a proximal non-patient needle <b>54</b> in fluid communication with the flash chamber <b>98.</b> Accordingly, when the distal patient needle <b>52</b> is provided access with a patient's vasculature, blood may flow from the patient through the distal patient needle <b>52</b> and into the flash chamber <b>98.</b> When the proximal non-patient needle <b>54</b> is engaged with an evacuated specimen collection container (not shown), blood may flow from the flash chamber <b>98</b> and through the proximal non-patient needle.

0044In one embodiment, the hub <b>64</b> may include an interior <b>100</b> between a portion of the rear hub portion <b>68</b> and a portion of the forward hub portion <b>70.</b> A flash chamber <b>98</b> may be formed within at least a portion of the interior <b>100</b> of the hub <b>64.</b> In one configuration, the hub <b>64,</b> or at least a portion of the hub <b>64,</b> such as the forward hub portion <b>70,</b> may be constructed from a transparent or translucent material, such as a polymeric material or resin. Alternatively, a flash chamber <b>98</b> may be integrally formed within another portion of the housing <b>32,</b> such as integrally formed with the specimen collection container holder <b>78,</b> or within a portion of a secondary tubular sidewall <b>86.</b>

0045In use, blood flow from a patient through the cannula <b>34</b> will enter the flash chamber <b>98</b> through the opening <b>88</b> in the cannula <b>34,</b> thereby partially filling the flash chamber <b>98</b> with blood. The flash chamber <b>98</b> provides a visual mechanism for recognition of venous access to a medical practitioner. Example flashback indicators are described, for example, in <patcit id="pcit0008" dnum="US20050004524A"><text>United States Patent Publication No. 2005/0004524</text></patcit>, the entire disclosure of which is herein incorporated by reference.

0046The needle assembly <b>30</b> further includes a safety shield <b>36,</b> which provides a mechanism to shield the cannula <b>34,</b> and in particular the puncture tip at the patient end <b>40,</b> after use thereof. At least a portion of the safety shield <b>36</b> is restrainably engaged with a portion of the housing <b>32</b> and transitionable from a retracted position, as shown in <figref idref="f0001"><b>FIGS. 1</b></figref><b>,</b><figref idref="f0003"><b>5</b></figref><b>,</b><figref idref="f0004"><b>7</b></figref><b>,</b> and <figref idref="f0005"><b>9</b></figref><b>,</b> to an extended position, as shown in <figref idref="f0001"><b>FIGS. 2</b></figref><b>,</b><figref idref="f0003"><b>6</b></figref><b>,</b><figref idref="f0004">8</figref>, and <figref idref="f0005"><b>10</b></figref><b>.</b> The safety shield <b>36</b> may be transitionable from the retracted position to the extended position over a portion of the cannula <b>34.</b> In one embodiment, the safety shield <b>36</b> is axially transitionable over the cannula <b>34.</b> In a further embodiment, the safety shield <b>36</b> is axially transitionable over the cannula <b>34</b> from a retracted position, in which at least the puncture tip of the patient end <b>40</b> of the cannula <b>34</b> is exposed, such as for accessing a patient, to an extended position, in which at least the puncture tip of the patient end <b>40</b> of the cannula <b>34</b> is shielded by at least a portion of the safety shield <b>36.</b> As used herein, the phrase "shielded by at least a portion of the safety shield" means that accidental contact with the puncture tip at the patient end <b>40</b> of the cannula <b>34</b> is prevented by the position of at least a portion of the safety shield in shielding orientation with respect to the patient end <b>40</b> of the cannula <b>34.</b> In one embodiment, the safety shield <b>36</b> at least partially surrounds or encompasses the patient end <b>40</b> of the cannula <b>34</b> in the extended position.

0047In one embodiment, as shown specifically in <figref idref="f0003 f0004 f0005"><b>FIGS. 5-10</b></figref><b>,</b> the shield <b>36</b> may be disposed within an interior portion <b>106</b> of the housing <b>32,</b> such as between the sidewall <b>84</b> and the second sidewall <b>86</b> of the housing <b>32,</b> in the retracted position. For example, the safety shield <b>36</b> may be disposed between a sidewall <b>84</b> forming a portion of the specimen collection container holder <b>78</b> and a second sidewall <b>86</b> disposed about the sidewall <b>84.</b> The safety shield <b>36</b> may have any suitable dimensions and configuration such that it is adapted to shield the puncture tip of the patient end <b>40</b> of the cannula <b>34</b> when the safety shield <b>36</b> is actuated to extend to the extended position, as shown in <figref idref="f0001"><b>FIG. 2</b></figref><b>.</b> In one embodiment, transition of the safety shield <b>36</b> from the retracted position to the extended position may be initiated once the puncture tip of the patient end <b>40</b> of the cannula <b>34</b> has been removed from the patient. In another embodiment, transition of the safety shield <b>36</b> from the retracted position to the extended position, may be initiated while the cannula <b>34</b> is in communication with the body of a patient, such as while the patient end <b>40</b> of the cannula <b>34</b> is in fluid communication with the vasculature of a patient. Accordingly, the safety shield <b>36</b> may be deployed over the cannula <b>34</b> while the cannula <b>34</b> is accessing the interior of the patient's blood vessel (not shown), or after the cannula <b>34</b> has been removed from the patient. If the transition of the safety shield <b>36</b> from the retracted position to the extended position occurs while the cannula <b>34</b> is accessing the interior of a patient's blood vessel, the distal portion <b>102</b> of the safety shield <b>36</b> will contact the patient's skin.

0048In one embodiment, the shield <b>36</b> includes a shielding portion <b>104</b> which is axially moveable in the direction of the longitudinal axis <b>A</b> of the cannula <b>34,</b> shown in <figref idref="f0003"><b>FIG. 5</b></figref><b>,</b> from the retracted position to the extended position. The shielding portion <b>104</b> may be restrainably engaged within the interior portion <b>106</b> of the housing <b>32</b> in the retracted position, and the shielding portion <b>104</b> may extend from the interior portion <b>106</b> of the housing <b>32</b> in the extended position. In one embodiment, axial transition of the shield <b>36</b> from the retracted position to the extended position transitions the shielding portion <b>104</b> from within the interior portion <b>106</b> of the housing <b>32</b> to a location at least partially exterior to the housing <b>32</b> substantially along the longitudinal axis A of the cannula <b>34.</b> In another embodiment, the interior portion <b>106</b> of the housing <b>32</b> may be circumferentially disposed about the specimen collection container holder <b>78</b> or specimen collection container receiving port <b>76.</b> In yet another embodiment, the interior portion <b>106</b> of the housing <b>32</b> is co-axial with the specimen collection container holder <b>78</b> or specimen collection container receiving port <b>76.</b> As used herein, the term "co-axial" includes orientations in which the interior portion <b>106</b> and the specimen collection container holder <b>78</b> or specimen collection container receiving port <b>76</b> are each disposed about the longitudinal axis A of the cannula <b>34.</b> In a further embodiment, the safety shield <b>36</b> is disposed about at least a portion of the cannula <b>34,</b> and transition of the safety shield <b>36</b> from the retracted position to the extended position telescopes the safety shield <b>36</b> over a portion of the cannula <b>34.</b> Optionally, the safety shield <b>36</b> may be substantially circumferentially disposed about at least a portion of the cannula <b>34.</b> It is also contemplated herein that the safety shield <b>36</b> may include a single telescoping portion, such as shielding portion <b>104,</b> or may include multiple circumferentially disposed nesting segments that are each transitionable over the cannula <b>34.</b>

0049The safety shield <b>36</b> may be deployed by a release member <b>108,</b> such as a push button, transitionable from a first position to a second position. The release member <b>108</b> may be deployable through an exterior surface <b>110</b> of the safety shield <b>36</b> and housing <b>32.</b> In one embodiment, the release member <b>108</b> may actuate the transition of the safety shield <b>36</b> from the retracted position to the extended position. In another embodiment, the release member <b>108</b> may initiate an activator to transition the safety shield <b>36</b> from the retracted position to the extended position. In the embodiment depicted in <figref idref="f0001 f0002 f0003 f0004 f0005"><b>FIGS. 1-10</b></figref><b>,</b> the release member <b>108</b> includes a member <b>112,</b> such as an arm, oriented in a substantially perpendicular orientation with respect to the transition axis <b>T</b> of the safety shield <b>36,</b> shown in <figref idref="f0003"><b>FIG. 6</b></figref><b>.</b> As used herein, the phrase "transition axis" includes the orientation of the shield during transition from the retracted position to the extended position. In certain embodiments, the transition axis is aligned with the longitudinal axis A of the cannula <b>34.</b> The member <b>112</b> may be connected to a restraining portion <b>114,</b> such as an enlarged body, creating a passage region <b>116,</b> such as a narrowed neck, as shown in <figref idref="f0002"><b>FIG. 3</b></figref><b>.</b> In one embodiment, the passage region <b>116</b> defines a non-enclosed region, such as an indentation or a cut-away portion. The restraining portion <b>114</b> of the release member <b>112</b> further includes a shoulder <b>118</b> adjacent the passage region <b>116.</b> Further, as shown in <figref idref="f0002"><b>FIG. 3</b></figref><b>,</b> safety shield <b>36</b> includes an elongated channel <b>120</b> extending through the shield <b>36,</b> with an enlarged opening adjacent the forward or distal end thereof, creating a stop surface shoulder <b>122</b> adjacent the forward edge of the channel <b>120.</b> In one embodiment, the elongated channel <b>120</b> extends longitudinally through the shield <b>36</b> along a top surface thereof.

0050With the safety shield <b>36</b> in the retracted position as shown in <figref idref="f0001"><b>FIG. 1</b></figref><b>,</b> the release member <b>108</b> is in a first position, with the restraining portion <b>114</b> extending into the shield <b>36,</b> and with the stop surface shoulder <b>122</b> in an abutting engagement with the shoulder <b>118</b> of the release member <b>108,</b> thereby preventing movement of the safety shield <b>36</b> in a forward or distal direction. When release member <b>108,</b> such as a push button, is transitioned from the first position, such as depressed in the direction of arrow <b>A</b> in <figref idref="f0002"><b>FIG. 3</b></figref><b>,</b> the restraining portion <b>114</b> moves in a substantially downward orientation with respect to safety shield <b>36,</b> thereby releasing the abutting engagement between stop surface shoulder <b>122</b> and the shoulder <b>118.</b> As such, the sidewall <b>124</b> of the safety shield <b>36</b> adjacent elongated channel <b>120</b> can guide through the passage region <b>116</b> of the release member <b>108</b> unobstructed, thereby permitting safety shield <b>36</b> to transition from the retracted position shown in <figref idref="f0001"><b>FIG. 1</b></figref> to the extended position shown in <figref idref="f0001"><b>FIG. 2</b></figref><b>.</b> Accordingly, the restraining portion <b>114</b> of the release member <b>108</b> engages a stop surface shoulder <b>122</b> of the shield <b>36</b> in the restrained position, and the stop surface shoulder <b>122</b> of the shield <b>36</b> passes through the passage region <b>116</b> of the release member <b>108</b> upon transition of the release member from a first position to a second position and transition of the shield <b>36</b> from the restrained position to the extended position.

0051In one embodiment, the safety shield <b>36</b> may be biased toward the extended position by a spring <b>126</b> disposed between a portion of the safety shield <b>36</b> and a portion of the housing <b>32.</b> The safety shield <b>36</b> may be biased toward the extended position by the spring <b>126</b> when the shield <b>36</b> is in the retracted position. In one embodiment, the spring <b>126</b> may be disposed between a proximal portion <b>128</b> of the safety shield <b>36</b> and a proximal end <b>72</b> of the housing <b>32.</b> In another embodiment, as shown in <figref idref="f0004 f0005"><b>FIGS. 7-10</b></figref><b>,</b> the spring <b>126</b> may be disposed between the sidewall <b>84</b> of the housing <b>32</b> and the second sidewall <b>86.</b> Upon transition of the release member <b>108</b> from the first position to the second position, the abutting engagement between the stop surface shoulder <b>122</b> and the shoulder <b>118,</b> shown in <figref idref="f0002"><b>FIG. 3</b></figref><b>,</b> is released and the spring <b>126</b> biases the safety shield <b>32</b> to the extended position thereby safely shielding the cannula <b>32.</b>

0052As shown in <figref idref="f0005"><b>FIGS. 9-10</b></figref><b>,</b> the safety shield <b>36</b> may further be provided with a barrier mechanism <b>130</b> structured to prevent the safety shield <b>36</b> from transitioning from the extended position to the retracted position once the safety shield <b>36</b> has been transitioned from the retracted position to the extended position. Accordingly, the barrier mechanism <b>130</b> prevents re-entry of the shield <b>36</b> into the housing <b>32</b> and exposure of cannula <b>34</b> after it has been shielded. In the embodiment, at least one of the distal end <b>74</b> of the housing <b>32</b> and the proximal portion <b>128</b> of the shield <b>36</b> include a barrier mechanism <b>130.</b> In another embodiment, both the distal end <b>74</b> of the housing <b>32</b> and the proximal portion <b>128</b> of the shield <b>36</b> include a barrier mechanism <b>130.</b>

0053The barrier mechanism <b>130</b> may include a restraint <b>132</b> and a break <b>134.</b> The break <b>134</b> may include a slanted distal portion <b>136</b> and a proximal portion <b>138</b> having a plane substantially perpendicular to a portion of the safety shield <b>36.</b> The break <b>134</b> is sized to allow passage beyond the restraint <b>132</b> included within the distal end <b>74</b> of the housing <b>32</b> when the safety shield <b>36</b> is transitioned from the restrained position to the extended position. The proximal portion <b>138</b> of the break <b>134</b> is also dimensioned to restrain the safety shield <b>36</b> against the restraint <b>132</b> to resist passage of the safety shield <b>36</b> past the restraint <b>132</b> once the shield <b>36</b> is transitioned from the retracted position to the extended position. In another embodiment, the release member <b>108</b> may be at least partially restrained by a portion of the shield <b>36,</b> such that the shield <b>36</b> cannot be reset after transitioning from the retracted position to the extended position.

0054As shown in <figref idref="f0001"><b>FIGS. 1</b></figref><b>,</b><figref idref="f0003"><b>5</b></figref><b>,</b><figref idref="f0004"><b>7</b></figref><b>,</b> and <figref idref="f0005"><b>10</b></figref><b>,</b> the flash chamber <b>98</b> is at least partially visible to a medical practitioner when the safety shield <b>36</b> is in the retracted position. In one embodiment, at least a portion of the flash chamber <b>98</b> extends beyond the distal portion <b>102</b> of the safety shield <b>32</b> in the retracted position. In another embodiment, at least a portion of the flash chamber <b>98</b> is visible through at least a portion of the shield <b>36</b> in the retracted position. In another embodiment, at least a portion of the shield <b>36</b> through which the flash chamber <b>98</b> is visible made of a translucent or transparent material.

0055As shown in <figref idref="f0006 f0007 f0008 f0009 f0010"><b>FIGS. 11-15B</b></figref><b>,</b> an alternative flash chamber, such as described in <patcit id="pcit0009" dnum="US20060036219A"><text>United States Publication No. 2006/0036219, filed August 16, 2004</text></patcit>, and <patcit id="pcit0010" dnum="US04435408A"><text>United States Application Serial No. 12/044,354, filed March 7, 2008</text></patcit>, the entire disclosure of each of which is herein incorporated by reference, may be employed within the present invention.

0056In addition to conventional flash chambers which may include a vent mechanism in communication with an external environment surrounding the needle assembly, it is also contemplated herein that a needle assembly may include a flash chamber having a vent plug which seals upon flow of blood into the flashback chamber, thereby inhibiting any pressurized air that may build up within the chamber, from moving in a reverse direction toward the inlet of the cannula. As shown in <figref idref="f0006 f0007 f0008 f0009 f0010"><b>FIGS. 11-15B</b></figref><b>,</b> it is also contemplated herein that a similar vent plug may be positioned within the housing at a location such that the vent plug divides the housing into two chambers having sizes and dimensions to establish predetermined volumes thereto. Moreover, the porous vent remains porous to blood and does not seal upon contact with blood. Desirably, the blood does not contact the vent plug at the initial flash indication, but such sealing occurs at a later point during use of the assembly, as will be described in more detail herein.

0057For example, as shown in <figref idref="f0006 f0007 f0008"><b>FIGS. 11-14</b></figref><b>,</b> a porous vent is positioned within the housing at a location such that the vent divides the housing into two chambers having sizes and dimensions to establish predetermined volumes thereto, so that the blood does not contact the porous vent for at the initial flash indication, but such contact occurs at a later point during use of the assembly, as will be described in more detail herein.

0058As shown in <figref idref="f0006 f0007 f0008"><b>FIGS. 11-14</b></figref><b>,</b> needle assembly <b>410</b> includes a housing <b>412</b> having a fluid inlet end or first end <b>414</b> and a fluid outlet end or second end <b>416.</b> Needle assembly <b>410</b> includes exterior wall <b>418</b> defining the housing interior. Exterior wall <b>418</b> extends generally longitudinally at the first end <b>414</b> forming an elongate longitudinal first portion <b>419</b> having a first diameter. At second end <b>416,</b> exterior wall <b>418</b> forms a second portion <b>421</b> that has a second diameter that is generally larger than the first diameter of the first portion <b>419.</b> Accordingly, housing <b>412</b> may form a structure having a generally T-shaped cross-section. The exterior wall <b>418</b> at second end <b>416</b> may be a separate element <b>428</b> that is attachable to main body portion <b>430</b> forming housing <b>412,</b> thereby assisting in manufacture and assembly of needle assembly <b>410.</b> First portion <b>419</b> and second portion <b>421</b> may be arranged relative to each other in a variety of arrangements, so long as they are capable of functioning for transport of air therebetween as discussed herein.

0059Needle assembly <b>410</b> further includes a fluid inlet cannula <b>436</b> extending from first end <b>414</b> of housing <b>412.</b> Fluid inlet cannula <b>436</b> includes an exterior end <b>439</b> that defines a sharpened bevel at patient puncture tip <b>438,</b> and extends within first end <b>414</b> of housing <b>412,</b> and may be fixedly mounted therein. Fluid inlet cannula <b>436</b> is characterized further by a substantially cylindrical lumen extending between the ends and communicating with the interior of housing <b>412.</b>

0060Needle assembly <b>410</b> also includes a non-patient puncture tip extending from second end <b>414</b> of housing <b>412</b>. As seen in <figref idref="f0007"><b>FIG. 13</b></figref><b>,</b> this may be accomplished by providing needle assembly <b>410</b> with a second cannula in the form of fluid outlet cannula <b>452.</b> In particular, the end of fluid outlet cannula <b>452</b> may define a sharpened bevel forming non-patient puncture tip <b>462.</b> Fluid outlet cannula <b>452</b> extends within second end <b>416</b> of housing <b>412,</b> and may be fixedly mounted therein. Fluid outlet cannula <b>452</b> is characterized further by a substantially cylindrical lumen communicating with the interior of housing <b>412.</b> Fluid outlet cannula <b>452</b> is mounted within housing <b>412</b> so that an interior end <b>464</b> passes substantially coaxially therein such that fluid outlet cannula <b>452</b> substantially aligns axially with the interior end of inlet cannula <b>436.</b> Desirably, this is achieved by mounting fluid outlet cannula <b>452</b> at a location adjacent second end <b>416</b> of housing <b>412,</b> such that the interior end <b>464</b> of fluid outlet cannula <b>452</b> extends within housing <b>412</b> to a location adjacent the interior end <b>439</b> of inlet cannula <b>436.</b> Additionally, the interior end <b>464</b> of fluid outlet cannula <b>452</b> is spaced only a small distance from the interior end <b>439</b> of inlet cannula <b>436,</b> thereby forming an axial gap therebetween for flow of blood into flash chamber <b>426</b> about fluid outlet cannula <b>452.</b> The distance between the interior end <b>464</b> of fluid outlet cannula <b>452</b> and the interior end <b>439</b> of inlet cannula <b>436</b> forming the axial gap is sufficient to provide for flow of blood into the flash chamber <b>426</b> based upon the patient's blood pressure after venipuncture. In certain embodiments, an axial gap that is less than 0.5mm may result in a flashback that is inconsistent.

0061As seen in <figref idref="f0008"><b>FIG. 14B</b></figref><b>,</b> fluid inlet cannula <b>436</b> and fluid outlet cannula <b>452</b> are positioned and dimensioned within housing <b>412</b> so as to achieve both desirable flow of blood through assembly <b>410</b> and to achieve effective flashback indication. In particular, wall <b>418</b> of housing <b>412</b> is dimensioned to provide a radial gap around fluid outlet cannula <b>452</b> of about 0.2mm at an area surrounding the internal end <b>464</b> thereof. This gap achieves a substantially laminar blood flow within flashback chamber <b>426</b> and prevents blood hemolysis. Additionally, the small radial gap between the inner surface of wall <b>418</b> and fluid outlet cannula <b>452</b> at the area surrounding the internal end <b>464</b> enables a drop of blood to be spread thinly across the radial gap in flashback chamber <b>426</b> to provide a magnified flashback indication with a very small volume of blood. Thus, an easily visualized flashback indication is achieved quickly at the first appearance of blood within flashback chamber <b>426.</b> It is contemplated herein that internal end <b>464</b> of outlet cannula <b>452</b> may be partially supported within housing <b>412,</b> so long as blood flow into flashback chamber <b>426</b> is achieved about the internal end <b>464.</b>

0062In an alternate arrangement, a single cannula is provided. Such an arrangement is depicted in the embodiment of <figref idref="f0009 f0010"><b>FIGS. 15A-15B</b></figref> (shown in connection with a blood collection assembly as will be described in more detail herein). In such an arrangement, the fluid inlet cannula and the fluid outlet cannula represent one single cannula <b>470,</b> having a patient puncture tip <b>438</b> a non-patient puncture tip <b>462,</b> and a lumen <b>442</b> extending therethrough, and with the body of the cannula <b>470</b> being fixedly attached to a portion of the housing <b>412</b> and passing entirely through housing <b>412.</b> A portion of cannula <b>470</b> extending through housing <b>412</b> includes one or more openings such as slot or aperture <b>444</b> to provide communication between lumen <b>442</b> and flashback chamber <b>436</b> within housing <b>412.</b> In the embodiment shown in <figref idref="f0009 f0010"><b>FIGS. 15A-15B</b></figref><b>,</b> two separate apertures <b>444</b> are shown on opposing sides of cannula <b>470,</b> although it is contemplated that any number of openings or apertures <b>444</b> can be included to provide for blood flow into the flash chamber <b>436.</b>

0063Returning to the embodiment of <figref idref="f0006 f0007 f0008"><b>FIGS. 11-14</b></figref><b>,</b> needle assembly <b>410</b> further includes a sealable sleeve <b>461</b> mounted to fluid outlet end <b>416</b> of housing <b>412.</b> This may be accomplished by providing a mounting protrusion <b>429</b> at second end <b>416</b> of housing <b>412,</b> such as on element <b>428,</b> with sealable sleeve <b>461</b> representing an elastomeric element that can be frictionally fit or otherwise affixed over protrusion <b>429.</b> Sealable sleeve <b>461</b> covers non-patient puncture tip <b>462</b> at the exterior end of fluid outlet cannula <b>452</b> when sealable sleeve <b>461</b> is in an unbiased condition. However, sealable sleeve <b>461</b> can be collapsed in response to pressure exerted by the stopper of an evacuated tube for urging exterior end <b>460</b> of fluid outlet cannula <b>452</b> through both sealable sleeve <b>461</b> and the stopper of an evacuated tube, as known in the art.

0064The embodiment of <figref idref="f0006 f0007 f0008"><b>FIGS. 11-14</b></figref> further includes a porous vent <b>402</b> positioned within the interior of housing <b>412.</b> Porous vent <b>402</b> is positioned within housing <b>412</b> to divide housing <b>412</b> into two distinct chambers, namely a first chamber represented by flashback chamber <b>426</b> and a second chamber represented by secondary chamber <b>427.</b> Porous vent <b>402</b> may be constructed of a suitable material as described above with respect to vent plug <b>900,</b> albeit without the hydrophilic material that swells on contact. In this manner, porous vent <b>402</b> is adapted to vent air therethrough, and represents a porous structure including a plurality of pores that allow for passage of blood therethrough. As discussed in more detail herein, during use of needle assembly <b>410,</b> the internal pores within porous vent <b>402</b> at least partially fill with blood due to the negative pressure established within secondary chamber <b>427.</b> Such filled pores in combination with the negative pressure within secondary chamber <b>427</b> prevent air flow between the secondary chamber <b>427</b> and the flashback chamber <b>426,</b> and provide for fluid resistance of the blood through porous vent <b>402,</b> as will be described in further detail.

0065Desirably, porous vent <b>402</b> is positioned within the interior of housing <b>412</b> between first portion <b>419</b> and second portion <b>421.</b> In this manner, first portion <b>419</b> of housing <b>412</b> essentially defines the flashback chamber <b>426,</b> and second portion <b>421</b> of housing <b>412</b> essentially defines the secondary chamber <b>427.</b> Alternatively, porous vent <b>402</b> may be positioned within the interior of housing <b>412</b> at a location spanning the transition between the first diameter of first portion <b>419</b> and the second diameter of second portion <b>421,</b> as shown in the embodiment of <figref idref="f0009"><b>FIGS. 15A</b></figref> and <figref idref="f0010"><b>15B</b></figref><b>.</b> In any event, porous vent <b>402</b> is generally a cylindrically shaped member with a central opening therein axially encircling a portion of the cannula, particularly fluid outlet cannula <b>452.</b>

0066The interior volume of housing <b>412</b> is defined by the sum of the volumes of flashback chamber <b>426</b> and secondary chamber <b>427</b> as well as the volume represented by the pores of porous vent <b>402.</b> Such interior volume is configured so as to provide for certain attributes to the needle assembly <b>410,</b> in particular with respect to the ability of the secondary chamber <b>427</b> to be at least partially evacuated of a portion of air therein to establish a negative pressure therein upon application of an evacuated tube to needle assembly <b>410</b> during use thereof. Such negative pressure within secondary chamber <b>427</b> draws blood through the pores of porous vent <b>402</b> based on when blood contacts porous vent <b>402</b> and partially fills the pores thereof. In a particular embodiment of the invention, the overall interior volume of housing <b>412</b> may be from about 300 mm³ to about 400 mm³. Such a volume is particularly useful for the intended use of needle assembly <b>410</b> for conventional venipuncture for drawing a blood sample from a patient using a needle cannula having a conventional gauge for venipuncture as is known in the art. With such an internal volume, porous vent <b>402</b> is desirably positioned within housing interior so as to define flashback chamber <b>426</b> as having a volume that represents from about 5 percent to about 20 percent of the total overall volume of housing <b>412,</b> desirably from about 7 percent to about 12 percent of the total overall volume of housing <b>412,</b> including the volume of secondary chamber <b>427</b> and the volume of the pores within porous vent <b>402.</b> Such a ratio of the flashback chamber <b>426</b> to the total overall volume of the housing <b>412</b> assures that flashback chamber <b>426</b> has sufficient volume to properly visualize the initial flash, and desirably while preventing blood from fully contacting the porous vent <b>402</b> at initial venipuncture, based on the initial build-up of pressure within secondary chamber <b>427</b> caused by venous pressure forcing the blood into flashback chamber <b>426.</b> Such volume ratios are effective for the intended use as described in further detail herein, wherein blood flowing into flashback chamber <b>426</b> upon initial venipuncture does not contact porous vent <b>402,</b> and wherein at least a portion of the air is drawn out from secondary chamber <b>427</b> based upon application of an evacuated blood collection tube to the needle assembly <b>410.</b> In this manner, secondary chamber <b>427</b> can effectively draw blood from within flashback chamber <b>426</b> and from within fluid inlet cannula <b>436</b> toward secondary chamber <b>427,</b> such as into and through porous vent <b>402,</b> when patient puncture tip <b>438</b> is removed from the patient and is exposed to the external environment. In one particular embodiment, the total interior volume of the housing <b>412</b> is about 380 mm³, with the flashback chamber <b>426</b> having a volume of about 30 mm³, the secondary chamber <b>427</b> having a volume of about 300 mm³, and the pores of the porous vent <b>402</b> representing a volume of about 50 mm³.

0067Needle assembly <b>410</b> may be assembled as follows. Fluid inlet cannula <b>436</b> is positioned through first end <b>414</b> of housing <b>412</b> such that the open interior end <b>439</b> is positioned within an interior portion of housing <b>412</b> at first portion <b>419</b> and patient puncture tip <b>438</b> extends externally of first end <b>414.</b> Fluid outlet cannula <b>452</b> is positioned within housing <b>412</b> through the opposite end, such that open internal end <b>464</b> is positioned within an interior portion of housing <b>412</b> at first portion <b>419</b> adjacent interior end <b>439</b> of fluid inlet cannula <b>436,</b> with a slight gap therebetween, and with non-patient puncture tip extending externally of second end <b>416.</b> Fluid inlet cannula <b>436</b> and fluid outlet cannula <b>452</b> may be affixed therein in any known manner, desirably through a medical grade adhesive.

0068In alternate embodiments including only a single cannula <b>470,</b> such cannula <b>470</b> is affixed within housing <b>412</b> such that opening <b>472</b> is positioned within the interior of housing <b>412</b> at first portion <b>419,</b> with patient puncture tip <b>438</b> extending externally of first end <b>414</b> and non-patient puncture tip <b>462</b> extending externally of second end <b>416.</b>

0069Porous vent <b>402</b> is then inserted within housing <b>412</b> and positioned over fluid outlet cannula <b>452</b> (or over the single cannula <b>470</b>), and element <b>428</b> is thereafter affixed to the second end <b>416,</b> enclosing the interior of housing <b>412.</b> Sealable sleeve <b>461</b> is then affixed over protrusion <b>429.</b> As such, the interior of housing <b>412</b> is closed from the external environment, with the sole path for fluid communication between the interior of housing <b>412</b> and the external environment being provided through the patient puncture tip <b>438.</b>

0070Needle assembly <b>410</b> assembled as such can be used in connection with a blood collection tube holder <b>403,</b> as depicted in the embodiment shown in <figref idref="f0009 f0010"><b>FIGS. 15A-15D</b></figref><b>.</b>

0071In use, needle assembly <b>410</b> may be provided with collection tube holder <b>403</b> attached thereto. Patient puncture tip <b>438</b> is inserted through the skin of a patient and into the patient's vasculature, desirably into a vein. Upon venipuncture, a closed environment is achieved within housing <b>412,</b> since housing <b>412</b> is an entirely closed structure, and since sealable sleeve <b>461</b> closes off the only outlet of housing <b>412</b> (i.e., fluid outlet cannula <b>452</b>). The patient's blood pressure causes blood to flow through patient puncture tip <b>438,</b> into fluid inlet cannula <b>436,</b> and out interior end <b>439</b> (or through opening <b>472</b> in the embodiment of <figref idref="f0009 f0010"><b>FIGS. 15A-15B</b></figref>), into flashback chamber <b>426</b> surrounding interior end <b>464</b> of fluid outlet cannula <b>452.</b> The transparent or translucent nature of housing <b>412</b> permits visualization of the blood within flashback chamber <b>426,</b> providing an indication that venipuncture is achieved.

0072Since the interior of housing <b>412</b> is a closed environment, the flow of blood into flashback chamber <b>426</b> causes air to be trapped within the housing interior, including within flashback chamber <b>426,</b> porous vent <b>402</b> and secondary chamber <b>427,</b> as well as within fluid outlet cannula <b>452,</b> causing such trapped air to be slightly pressurized therein. Flashback chamber <b>426</b> and secondary chamber <b>427</b> are configured through their size and dimensions such that the volumes thereof permit blood to flow into flashback chamber <b>426</b> at this initial venipucture, but the build up of air pressure within the pores of porous vent <b>402</b> and within secondary chamber <b>427</b> prevents blood from fully contacting porous vent <b>402,</b> and desirably prevents blood from even partially contacting porous vent <b>402</b> at the initial venipuncture.

0073After such initial venipuncture and flash visualization, a sample collection container having a negative pressure therein, such as an evacuated blood collection tube (not shown) as is commonly known in the art, is inserted within the tube holder <b>403.</b> The stopper (not shown) of such evacuated container contacts and displaces sealable sleeve <b>461,</b> causing non-patient puncture tip <b>462</b> to puncture through sealable sleeve <b>461</b> and through the stopper of the evacuated container. At this point, fluid communication is established between the non-patient puncture tip <b>462</b> and the interior of the evacuated collection container. The negative pressure within the evacuated collection container draws the blood that has collected within flashback chamber <b>426</b> into fluid outlet cannula <b>452</b> and into the evacuated collection container. Along with the blood within flashback chamber <b>426,</b> the negative pressure within the evacuated collection container will also draw at least a portion of the air out of the flashback chamber <b>426</b> and out of the secondary chamber <b>427</b> through the pores of the porous vent <b>402,</b> toward and into the evacuated collection container. In addition, the close proximity and alignment of fluid outlet cannula <b>452</b> and fluid inlet cannula <b>426</b> causes blood to be drawn from fluid inlet cannula <b>436</b> and from the patient, simultaneously with such air being drawn from the flashback chamber <b>426</b> and secondary chamber <b>427.</b>

0074Such drawing of air reduces the pressure within the flashback chamber <b>426</b> and the secondary chamber <b>427,</b> establishing a negative pressure therein with respect to the patient's blood stream and with respect to the external environment. This negative pressure that has been established within the interior of housing <b>412,</b> and specifically within flashback chamber <b>426</b> and secondary chamber <b>427,</b> draws additional blood from within fluid inlet cannula <b>436</b> and from the patient into flashback chamber <b>426,</b> with the blood contacting porous vent <b>402.</b> With such blood filling flashback chamber <b>426,</b> the blood fully contacts the surface of porous vent <b>402</b> that extends within flashback chamber <b>426,</b> and begins to fill the pores of porous vent <b>402.</b> Such filling of the pores of porous vent <b>402</b> that are directly at the interface of porous vent <b>402</b> and flashback chamber <b>426</b> closes off the porous vent <b>402</b> from airflow therethrough but does not fully act as a seal, in that the blood does not cause the material of the porous vent <b>402</b> to swell or close off to air flow, but instead merely physically fills the voids within the porous vent <b>402.</b> Moreover, since a portion of the air within secondary chamber <b>427</b> has been drawn out form secondary chamber <b>427,</b> the secondary chamber <b>427</b> represents a closed chamber with a negative pressure therein relative to the external environment. Secondary chamber <b>427</b> will therefore continue to have a drawing effect on the blood within the pores of porous vent 402 and within flashback chamber <b>426</b> through the pores of porous vent <b>402</b> toward secondary chamber <b>427,</b> without releasing any air from the secondary chamber <b>427</b> in the opposite direction due to the pores of porous vent <b>402</b> at the interface of the flashback chamber <b>426</b> being filled with blood, thereby effectively preventing air flow through porous vent <b>402</b> due to the filled pores. The draw created by negative pressure within secondary chamber <b>427</b> has a fluid resistance based on the blood filling the pores of porous vent <b>402</b> and based on the tortuous path created by the pores of the porous vent <b>402,</b> and therefore is a gradual draw with reduced fluid movement.

0075At this point, the evacuated collection container and the secondary chamber <b>427</b> are both at a negative pressure with respect to the external environment (and with respect to the patient's bloodstream), and therefore both effect a draw from the fluid inlet cannula <b>436.</b> This effect may essentially establish an equilibrium within the flashback chamber <b>426,</b> such that the blood contained within the flashback chamber <b>426</b> is not drawn toward or into either the secondary chamber <b>427</b> through the pores of porous vent <b>402</b> or into the evacuated collection container (through the fluid inlet cannula <b>436</b>), but instead essentially remains within flashback chamber <b>426</b> in a steady state. The negative pressure of the evacuated collection container draws blood directly from the patient through fluid inlet cannula <b>436,</b> due to the close proximity and alignment of fluid outlet cannula <b>452</b> and fluid inlet cannula <b>436,</b> as well as due to the equilibrium established within flashback chamber <b>426</b> (based on the opposite draw forces between the evacuated collection container and the evacuated secondary chamber <b>427</b>). The continual draw of blood into the evacuated collection container gradually causes the pressure within the collection container to increase.

0076Once the evacuated collection container is filled with the desired amount of blood, the container is removed from the non-patient puncture tip <b>462,</b> thereby releasing the fluid communication between the non-patient puncture tip <b>462</b> and the evacuated collection container, with sealable sleeve <b>461</b> then covering and closing off non-patient puncture tip <b>462.</b> Absent such draw from the negative pressure of the evacuated collection tube, the negative pressure within the secondary chamber <b>427</b> effects a slight draw on the blood within flashback chamber <b>426</b> through the pores of porous vent <b>402.</b> Such draw, however, is very slow and gradual, due to the tortuous path of blood flow through the pores of porous vent <b>402.</b>

0077Additional evacuated collection containers can thereafter be inserted into tube holder <b>403</b> and used for sample collection through non-patient puncture tip <b>462</b> as described above, by placing a second evacuated collection container within the holder <b>403</b> and establishing fluid communication between the non-patient puncture tip <b>462</b> and the interior of the evacuated collection container by puncturing the stopper, as discussed. In such further sampling, the evacuated collection container and the secondary chamber <b>427</b> are both at a negative pressure, and therefore both effect a draw from the fluid inlet cannula <b>436.</b> As above, this effect essentially establishes an equilibrium within the flashback chamber <b>426,</b> thereby preventing the blood contained within the flashback chamber <b>426</b> from being drawn toward or into the secondary chamber <b>427</b> (through the porous vent <b>402</b>). The negative pressure of the evacuated collection container draws blood directly from the patient through fluid inlet cannula <b>436</b> as discussed above, due to the close proximity and alignment of fluid outlet cannula <b>452</b> and fluid inlet cannula <b>426.</b> Once any such additional evacuated collection containers are filled with the desired amount of blood, the container is removed from the non-patient puncture tip <b>462,</b> thereby releasing the fluid communication between the non-patient puncture tip <b>462</b> and the evacuated collection container, with sealable sleeve <b>461</b> then covering and closing off non-patient puncture tip <b>462.</b>

0078Once all of the desired blood samples have been drawn in this manner, patient puncture tip <b>438</b> is removed from the vasculature of the patient, thereby exposing the opening of patient puncture tip <b>438</b> to the external environment. Since the sole communication path between the housing interior and the external environment is through patient puncture tip <b>438,</b> the negative pressure established within secondary chamber <b>427</b> relative to the external environment will affect a gradual draw on the blood contained within flash chamber <b>426</b> and within fluid inlet cannula <b>436</b> toward and through porous vent <b>402</b>. Such drawing effect will move any blood contained within fluid inlet cannula <b>436</b> away from patient puncture tip <b>438,</b> thereby preventing any blood from leaking from patient puncture tip <b>438</b> out of fluid inlet cannula <b>436.</b> Such negative pressure within secondary chamber <b>427</b> may continue to have a gradual drawing effect through the porous vent <b>402</b> for a prolonged period of time after removal of patient puncture tip <b>438</b> from the patient, and may draw all of the remaining blood contained within fluid inlet cannula <b>436</b> and flashback chamber <b>426</b> through porous vent <b>402</b> and/or into secondary chamber <b>427.</b> Needle assembly <b>410</b> can then be properly disposed of in a known manner. It is anticipated herein, that the flash chamber <b>426</b> described with reference to <figref idref="f0006 f0007 f0008 f0009 f0010"><b>FIGS. 11-15B</b></figref> may be employed within any of the embodiments described elsewhere in the present application.

0079In yet another embodiment, <figref idref="f0011 f0012 f0013 f0014 f0015 f0016"><b>FIGS. 16-28</b></figref> depict an alternative configuration of a needle assembly <b>230</b> in accordance with the present invention. As shown, needle assembly <b>230</b> is similarly constructed to the needle assembly <b>30,</b> described above with reference to <figref idref="f0001 f0002 f0003 f0004 f0005"><b>FIGS. 1-10</b></figref><b>.</b> Needle assembly <b>230</b> includes an alternate release member <b>208</b> and an optional removable cannula guard <b>216.</b> Needle assembly <b>230</b> generally includes a cannula <b>234</b> associated with a housing <b>232,</b> and a safety shield <b>236</b> adapted for safety shielding the cannula <b>234</b> during and/or after use of the device. As previously described, the housing <b>232</b> may include a hub <b>264,</b> a specimen collection container receiving port <b>276</b> and/or a specimen collection container holder <b>278,</b> and a second sidewall <b>286</b> at least partially surrounding a sidewall <b>284</b> of the specimen collection container holder <b>278.</b> The hub <b>264</b> may be adapted for at least partially supporting the cannula <b>34,</b> which includes a patient end <b>240</b> and a non-patient end <b>242,</b> as previously described. The cannula <b>34</b> may also include a distal patient needle <b>252</b> and a separate proximal non-patient needle <b>254,</b> as also previously described. The needle assembly 230 further includes a flash chamber 298 defined therein, as previously described.

0080As shown in <figref idref="f0011">FIGS. 16</figref>,<figref idref="f0012">18</figref>, <figref idref="f0013">20</figref>, and <figref idref="f0013 f0015">21-25</figref>, the needle assembly 230 is shown in the retracted position with a removable cannula guard 216 associated with a portion of the housing 232 and generally shielding the cannula 234. The removable cannula guard 216 is engageable with a portion of the housing 232 and is removable prior to use of the needle assembly 230. The removable cannula guard 216 is provided to shield the cannula 234, in particular, the puncture tip of the patient end 240 of the cannula 234, prior to use in a specimen collection procedure. In one embodiment, the cannula guard 216 is configured to circumferentially surround the cannula 234. The cannula guard 216 has a proximal end 246 having an interior portion <b>248</b> sized to extend at least partially over a portion of the housing <b>232,</b> such as an exterior surface <b>253</b> of the hub <b>264.</b> In another embodiment, the removable cannula guard <b>216</b> has a proximal end <b>246</b> having an interior portions <b>248</b> sized to extend at least partially over the exterior surface <b>253</b> of the hub <b>264</b> and to extend within at least a portion of the interior <b>258</b> of the distal end <b>260</b> of the housing <b>232.</b>

0081The removable cannula guard <b>216</b> may be removably mated to a portion of the hub <b>264</b> and/or the specimen collection container holder <b>278,</b> such as by a frictional engagement or press-fit mechanism. Alternately, removable cannula guard <b>216</b> may be mated by a threaded engagement (not shown), in which threads (not shown) may be disposed on a portion of the hub <b>264,</b> or specimen collection container holder <b>278,</b> and/or removable cannula guard <b>216.</b> In one embodiment, the proximal end <b>246</b> of the removable cannula guard <b>216</b> may have an area of increased thickness <b>266,</b> as compared to the thickness of the remainder of the removable cannula shield <b>216,</b> to provide additional support for mating engagement with the housing <b>232.</b> In a further embodiment, the area of increased thickness <b>266</b> if provided is to provide additional support for mating engagement with the hub <b>264.</b>

0082The removable cannula guard <b>216</b> may have any suitable dimensions and may be made of any suitable materials to allow the puncture tip of the patient end <b>240</b> of the cannula <b>234</b> to remain shielded prior to use and/or during transport. In one embodiment, the removable cannula guard <b>216</b> has sufficient strength to allow the needle assembly <b>230</b> to be packaged as a "hardpack" packaging configuration, as is conventionally known, without damage to the cannula <b>234</b> or needle assembly <b>230.</b> An example removable cannula guard and an example hardpack packaging structures are disclosed, for example, in <patcit id="pcit0011" dnum="US6997913B"><text>United States Patent Nos. 6,997,913</text></patcit> and <patcit id="pcit0012" dnum="US6984223B"><text>6,984,223</text></patcit>, the entire disclosure of each of which are herein incorporated by reference.

0083Prior to use, the removable cannula guard <b>216</b> is removed from the needle assembly <b>230,</b> such as by applying force to disengage the frictional engagement or press-fit mechanism and/or unscrew the threaded engagement. Once the removable cannula guard <b>216</b> has been removed from the needle assembly <b>230,</b> a medical practitioner can use the needle assembly <b>230</b> as previously described herein.

0084Further, as shown specifically in <figref idref="f0016"><b>FIGS. 26-28</b></figref><b>,</b> the needle assembly <b>230</b> may include an alternative release member <b>208,</b> such as an alternative push button. In one embodiment, the release member <b>208</b> may actuate the transition of the safety shield <b>236</b> from the retracted position to the extended position. In another embodiment, the release member <b>208</b> may initiate an activator to transition the safety shield <b>236</b> from the retracted position to the extended position. In the embodiment depicted in <figref idref="f0016"><b>FIGS. 26-28</b></figref><b>,</b> the release member <b>208</b> includes a member <b>210</b> having a restraining portion <b>212</b> and a passage region <b>214,</b> as previously described. The restraining portion <b>212</b> may also define an interior recess <b>218</b> defined at least in part by two depending arms <b>220.</b> The interior recess <b>218</b> is dimensioned to accommodate at least a portion of the housing <b>232,</b> such as a portion of the hub <b>264,</b> therethrough. <figref idref="f0016"><b>FIGS. 26-27</b></figref> are partial perspective views of the needle assembly <b>230</b> having the shield and cannula removed therefrom to illustrate the mechanism of the release member <b>208.</b> When the release member <b>208</b> is in a first position, as shown in <figref idref="f0016"><b>FIG. 26</b></figref><b>,</b> the rim <b>222</b> may be provided such that it does not engage a portion of the hub <b>264.</b> When the release member <b>208</b> is transitioned to the second position, as shown in <figref idref="f0016"><b>FIG. 27</b></figref><b>,</b> both depending arms <b>220</b> are lowered and the rim <b>222</b> contacts a portion of the hub <b>264.</b>

0085As shown in <figref idref="f0016"><b>FIG. 26</b></figref><b>,</b> when the release member <b>208</b> is in a first position, corresponding to the retracted position of the shield (shown in <figref idref="f0011"><b>FIG. 16</b></figref>), the rim <b>222</b> of the interior recess <b>218</b> is separated from the hub <b>264</b> and restraining portions <b>224</b> of the depending arms <b>220</b> may contact at least a portion of the hub <b>264.</b> The safety shield is prevented from transitioning from the restrained position to the extended position by the restraining portion <b>212,</b> as similarly discussed herein in greater detail with reference to <figref idref="f0002"><b>FIGS. 3-4</b></figref><b>.</b> As shown in <figref idref="f0016"><b>FIG. 27</b></figref><b>,</b> when the release member <b>208</b> is deployed to the second position, corresponding to the extended position of the shield (shown in <figref idref="f0011"><b>FIG. 17</b></figref>), the rim <b>222</b> engages at least a portion of the hub <b>264.</b> The restraining portions <b>212</b> are advanced beyond the hub <b>264.</b> Once the restraining portions <b>212</b> have advanced beyond the hub <b>264,</b> the hub <b>264</b> prevents the release member <b>208</b> from being returned to its original state prior to activation, such as through a locking engagement with hub <b>264.</b> Also shown in <figref idref="f0011"><b>FIG. 17</b></figref><b>,</b> the needle assembly <b>230</b> may include a plurality of ribs <b>238</b> to prevent rotation of the safety shield <b>236</b> with respect to the housing <b>232,</b> such as with respect to the specimen collection container holder <b>278.</b>

0086As shown in <figref idref="f0015"><b>FIGS. 24-25</b></figref><b>,</b> the removable cannula guard <b>216</b> may further include a portion in abutment with a portion of release member <b>208,</b> thereby physically preventing deployment of the release member <b>208</b> until the removable cannula guard <b>216</b> is removed from the needle assembly <b>230.</b> In one embodiment, the removable cannula guard <b>216</b> includes a tab <b>274</b> that extends at least partially within the interior recess <b>218</b> (shown in <figref idref="f0016"><b>FIG. 28</b></figref>) of the release member <b>208,</b> thereby preventing transition of the release member <b>208</b> from a first position, as shown in <figref idref="f0011"><b>FIG. 16</b></figref><b>,</b> to a second position, as shown in <figref idref="f0011"><b>FIG. 17</b></figref><b>.</b> Accordingly, accidental transition of the safety shield <b>236</b> from a retracted position to the extended position is prevented during transport or standard pre-use handling.

0087Moreover, as shown in <figref idref="f0014"><b>FIGS. 22-23</b></figref><b>,</b> a tamper-resistant flange <b>278</b> may be provided adjacent the distal end <b>260</b> of the housing <b>232,</b> such as adjacent the distal end <b>282</b> of the second sidewall <b>286</b> to prevent the forced re-entry of the safety shield <b>236</b> into the housing <b>232</b> once the safety shield <b>236</b> has been transitioned from the retracted position to the extended position. In one embodiment, the flange <b>278</b> is attached to, or integral with, an exterior surface <b>284</b> of the second sidewall <b>286</b> at the distal end <b>282</b> and oriented to extend beyond the distal end <b>282</b> of the housing <b>232</b> in the distal direction. As shown in <figref idref="f0014"><b>FIG. 23</b></figref><b>,</b> when the needle assembly <b>230</b> is in the extended position, the flange <b>278</b> may shield a barrier mechanism <b>292,</b> similar to the barrier mechanism previously described herein with reference to <figref idref="f0005"><b>FIGS. 9-10</b></figref><b>.</b> The barrier mechanism <b>292</b> is structured to prevent the re-entry of the safety shield <b>236</b> into the housing <b>232</b> once the safety shield <b>236</b> has been transitioned from the retracted position to the extended position. However, in certain configurations, it may be possible to insert a pry tool (not shown) between the safety shield <b>236</b> and a portion of the housing <b>232</b> thereby flexing the needle assembly <b>230</b> to a sufficient degree that abutting portions of the barrier mechanism <b>292</b> can become disengaged, thereby allowing re-entry of the safety shield <b>236</b> into the housing <b>232.</b> In order to prevent insertion of such a pry tool, flange <b>278</b> may be provided to shield the distal end <b>260</b> of the housing <b>232</b> from tampering.

0088<figref idref="f0017 f0018 f0019 f0020 f0021 f0022"><b>FIGS. 29-38</b></figref> depict another embodiment of the present invention, in which a needle assembly <b>330</b> is similarly constructed as described above, with the exception of the configuration of the housing <b>332.</b> Needle assembly <b>330</b> generally includes a cannula <b>334</b> associated with the housing <b>332,</b> and a safety shield <b>336</b> adapted for safety shielding of the cannula <b>334</b> during and/or after use of the device. Needle assembly <b>330</b> further includes a hub <b>364</b> for supporting at least a portion of the cannula <b>334</b> and a flash chamber <b>398</b> as previously described.

0089In the embodiment shown in <figref idref="f0017 f0018 f0019 f0020 f0021 f0022"><b>FIGS. 29-38</b></figref><b>,</b> the housing <b>332</b> may include a first portion <b>344,</b> with a second portion <b>346</b> connected to the first portion <b>344.</b> The first portion <b>344</b> may be distal to the second portion <b>346</b> along the transition axis <b>T</b> (shown in <figref idref="f0018"><b>FIG. 32</b></figref>) of the shield <b>336.</b> In one embodiment, the first portion <b>344</b> and the second portion <b>346</b> are co-formed. In another embodiment, the first portion <b>344</b> and the second portion <b>346</b> are separately formed and subsequently assembled. In yet another embodiment, the first portion <b>344</b> and the secondary portion <b>346</b> may be secured together in a bayonet fashion. Alternatively, the first portion <b>344</b> and the secondary portion <b>346</b> may be adhered together through the use of conventional adhesives.

0090As shown in <figref idref="f0019"><b>FIGS. 33-34</b></figref><b>,</b> the cannula <b>334</b> may be positioned in part within the interior <b>350</b> of the secondary portion <b>346</b> and in part within the interior <b>352</b> of the first portion <b>344.</b> In another embodiment, the non-patient end <b>342</b> of the cannula <b>334</b> may be positioned within the interior <b>350</b> of the secondary portion <b>346,</b> and at least the puncture tip of the patient end <b>340</b> of the cannula <b>334</b> extending beyond the first portion <b>344.</b> The hub <b>364</b> may be positioned within the interior <b>352</b> of the first portion <b>344,</b> although in certain embodiments it may be desirable to position the hub <b>364</b> in part within the interior <b>350</b> of the secondary portion <b>346</b> and in part within the interior <b>352</b> of the first portion <b>344.</b> In another embodiment, the secondary portion <b>346</b> may include a conventional specimen collection container holder <b>378.</b> In yet another embodiment, a specimen collection container receiving port <b>380,</b> engageable with a specimen collection container (shown in <figref idref="f0077"><b>FIG. 123</b></figref>), is defined within the secondary portion <b>346.</b>

0091The flash chamber <b>398</b> is visible to a medical practitioner when the safety shield <b>336</b> is in the retracted position, as shown in <figref idref="f0017"><b>FIG. 29</b></figref><b>.</b> Referring again to <figref idref="f0017 f0018 f0019"><b>FIGS. 29-34</b></figref><b>,</b> the housing <b>332,</b> such as the first portion <b>344,</b> may include a sidewall <b>358</b> having an observation window <b>360,</b> shown in <figref idref="f0017 f0018"><b>FIGS. 29-32</b></figref><b>,</b> defined therein. In one embodiment, the observation window <b>360</b> includes an opening surrounded entirely by a sidewall <b>358.</b> In another embodiment, the observation window <b>360</b> includes a cut-away portion of the housing <b>332.</b> In another embodiment, the observation window <b>360</b> includes a translucent and/or transparent material within the opening. In yet another embodiment, the observation window <b>360</b> includes a cut-away portion that is at least partially open, i.e., the observation window <b>360</b> is not entirely surrounded by a sidewall <b>358</b> of the housing <b>332.</b>

0092In accordance with an embodiment of the present invention, at least a portion of the flash chamber <b>398</b> is visible through the observation window <b>360</b> when the shield <b>336</b> is in the retracted position. In another embodiment, at least a portion of the first portion <b>344</b> of the housing <b>332</b> defines an observation window <b>360</b> and the flash chamber <b>398</b> is visible through the observation window <b>360</b> of the first portion <b>344</b> of the housing <b>332</b> when the shield is in the retracted position. In another embodiment, the safety shield <b>336</b> may be formed of a translucent and/or transparent material such that the flash chamber <b>398</b> is visible through both the observation window <b>360</b> and a portion of the safety shield <b>336.</b> In another embodiment, both the safety shield <b>336</b> and the first portion <b>344</b> of the housing <b>332</b> are made of a transparent material or translucent material, such that the flash chamber <b>398</b> is visible through both structures. The first portion <b>344</b> and the safety shield <b>336</b> can be made of the same or different translucent and/or transparent materials. In another embodiment, the patient end <b>340</b> of the cannula <b>334</b> may include a bevel <b>338</b> and the position of the observation window <b>360</b> within the housing <b>332</b> corresponds to the orientation of the bevel <b>338,</b> i.e., the orientation of the angled surface of the bevel <b>338.</b> This may assist medical practitioners in properly orienting the cannula <b>334</b> within the patient without visually observing the patient end <b>340</b> of the cannula <b>334.</b>

0093As shown in <figref idref="f0019"><b>FIG. 33</b></figref><b>,</b> the safety shield <b>336</b> may be disposed entirely within the first portion <b>344</b> of the housing <b>332</b> in the retracted position. In one embodiment, the safety shield <b>336</b> is adapted to at least partially surround, such as circumferentially surround, at least a portion of the cannula <b>334.</b> In one embodiment, the safety shield <b>336</b> may be made of a substantially rigid material. In another embodiment, the safety shield <b>336</b> may be made of any substantially resilient deformable material having an elasticity sufficient that the safety shield <b>336</b> may be compressed and expanded without substantial damage thereof, such that it may be configured to fold against itself in an accordion folding arrangement.

0094As shown in <figref idref="f0019"><b>FIGS. 33-34</b></figref><b>,</b> a spring <b>368</b> may be biased between a portion of the safety shield <b>336</b> and a portion of first portion <b>344</b> of the housing <b>332.</b> In one embodiment, the spring <b>368</b> is biased between a proximal portion <b>372</b> of the shield <b>336</b> and an inner surface <b>384</b> of the interior <b>352</b> of the first portion <b>344.</b> In another embodiment, the spring <b>368</b> is biased between a proximal portion <b>372</b> of the shield <b>336</b> and a distal end <b>376</b> of the secondary portion <b>346.</b> In yet another embodiment, the spring <b>368</b> is biased between a biasing portion <b>388</b> of the safety shield <b>336</b> and either of an inner surface <b>384</b> of the interior <b>352</b> of the first portion <b>344</b> and a distal end <b>376</b> of the secondary portion <b>346.</b>

0095As shown in <figref idref="f0017 f0018 f0019 f0020 f0021 f0022"><b>FIGS. 29-38</b></figref><b>,</b> the safety shield <b>336</b> may be transitioned from the retracted position, shown in <figref idref="f0017"><b>FIG. 29</b></figref><b>,</b> to the extended position, shown in <figref idref="f0017"><b>FIG. 30</b></figref><b>,</b> by spring <b>368.</b> During transition of the safety shield <b>336</b> from the retracted position to the extended position, spring <b>368</b> advances the safety shield <b>336</b> from a position within the first portion <b>344</b> of the housing <b>332</b> to a location distal from the distal portion <b>392</b> of the first portion <b>344.</b> In this embodiment, the safety shield <b>336</b> is adapted to move between the retracted position, in which at least the puncture tip of the patient end <b>340</b> of the cannula <b>334</b> is exposed for accessing the patient, and the extended position in which the puncture tip of the patient end <b>340</b> is encompassed or otherwise safely shielded from exposure. The safety shield <b>336</b> may be at least partially deployed over the cannula <b>334</b> while the cannula <b>334</b> is accessing the interior of the patient's blood vessel (not shown), or after the cannula <b>334</b> has been removed from the patient. If the transition of the safety shield <b>336</b> from the retracted position to the extended position occurs while the cannula <b>334</b> is accessing the interior of a patient's blood vessel, the distal portion <b>394</b> of the safety shield <b>336</b> will contact the patient's skin.

0096In yet another embodiment, the needle assembly <b>330</b> may further include a barrier mechanism <b>396,</b> similar to the barrier mechanisms previously described, to prevent the safety shield <b>336</b> from re-entering the housing <b>332</b> once the safety shield <b>336</b> has been transitioned from the retracted position to the extended position. Alternatively, as shown in <figref idref="f0019"><b>FIGS. 33-34</b></figref><b>,</b> the restraint <b>390</b> and break <b>386</b> are shown in opposite arrangement, such that the break <b>386</b> is incorporated within the housing <b>332,</b> specifically the distal end <b>392</b> of the first portion <b>344,</b> and the restraint <b>390</b> is incorporated within the safety shield <b>336</b> adjacent a proximal portion <b>372</b> of the shield <b>336.</b>

0097As shown in <figref idref="f0017 f0018 f0019 f0020 f0021"><b>FIGS. 29-36</b></figref><b>,</b> a release member <b>308,</b> such as a push button, may actuate the transition of the safety shield <b>336</b> from the retracted position to the extended position. In another embodiment, the release member <b>308</b> may initiate an activator to transition the safety shield <b>336</b> from the retracted position to the extended position. In the embodiment depicted in <figref idref="f0017 f0018 f0019"><b>FIGS. 29-34</b></figref><b>,</b> the release member <b>308</b> may operate in a substantially similar fashion to the release members previously described, however, the passage region <b>310</b> may define at least one substantially circular opening. As shown in <figref idref="f0021"><b>FIG. 36</b></figref><b>,</b> the restraining portion <b>312</b> of the release member <b>308</b> may also define a partially circular opening. <figref idref="f0020"><b>FIG. 35</b></figref> shows a cut away view of the needle assembly <b>330</b> with the release member <b>308</b> in the first position, corresponding to the shield <b>336</b> in the retracted position. As shown in <figref idref="f0020"><b>FIG. 35</b></figref><b>,</b> the restraining portion <b>312</b> is engaged with at least a portion of the safety shield <b>336,</b> such that a shoulder <b>314</b> of the release member <b>308</b> prevents the safety shield <b>336</b> from transitioning to the extended position by the bias of the spring <b>368.</b> In this configuration, the restraining portion <b>312</b> and the passage region <b>310</b> define continuous partially circular openings having different diameters. In one embodiment, the passage region <b>310</b> has a diameter <b>D₁</b> and the restraining portion <b>312</b> has a diameter <b>D₂</b>, wherein <b>D₂</b> is smaller than <b>D₁</b>. When the release member <b>308</b> is in the first position, the safety shield <b>336</b> is at least partially aligned with and restrained by the diameter of the opening of the restraining portion <b>312,</b> thereby holding the safety shield <b>336</b> in the retracted position. When the release member <b>308</b> is transitioned to the second position, the restraining portion <b>312</b> is advanced below the safety shield <b>336</b> and the passage region <b>310,</b> having an opening of increased diameter is aligned with the safety shield <b>336,</b> thereby allowing the safety shield <b>336</b> to transition therethrough.

0098In one embodiment, the restraining portion <b>312</b> may be sized to circumferentially surround a portion of the housing <b>332,</b> such as the hub <b>364.</b> Optionally, the release member <b>308</b> may include a stabilizing feature for stabilizing the release member <b>308</b> in the first position and engaging a corresponding shoulder <b>318</b> of the housing <b>332,</b> such as shown in <figref idref="f0017"><b>FIGS. 29</b></figref> and <figref idref="f0020"><b>35</b></figref><b>.</b> In one embodiment, the stabilizing feature may include a detent protrusion <b>316,</b> such as two detent protrusions <b>316,</b> for engaging a corresponding shoulder <b>318</b> of the housing <b>332 and</b> stabilizing the release member <b>308</b> in the first position. When the release member <b>308</b> is depressed in the direction shown by arrow <b>R</b> in <figref idref="f0017"><b>FIGS. 29</b></figref> and <figref idref="f0021"><b>36</b></figref><b>,</b> the safety shield <b>336</b> is transitioned to the extended position, shown in <figref idref="f0017"><b>FIG. 30</b></figref><b>.</b> As the release member <b>308</b> is advanced in the direction shown by arrow <b>R,</b> the detent protrusions <b>316</b> are advanced in a downward direction and are received within a recess <b>320,</b> shown in <figref idref="f0020"><b>FIG. 35</b></figref><b>,</b> within the housing <b>332.</b> Due to the increased diameter of the passage region <b>310,</b> as compared to the diameter of the restraining portion <b>312,</b> and the presence of the detent protrusion <b>316</b> within the recess <b>320,</b> the safety shield <b>336</b> is advanced through the passage region <b>310,</b> thereby transitioning the safety shield <b>336</b> from the retracted position to the extended position.

0099Further, as shown in <figref idref="f0021 f0022"><b>FIGS. 37-38</b></figref><b>,</b> the needle assembly <b>330</b> may include a removable cannula guard <b>324</b> for surrounding the cannula <b>334,</b> particularly the puncture tip of the patient end <b>340,</b> prior to use. As previously described herein, the removable cannula guard <b>324</b> may include a tab portion <b>326</b> structured to prevent transitions of the release member <b>308</b> from a first position to a second position. In this embodiment, the tab portion <b>326</b> includes an upper surface <b>354</b> structured to face a lower surface <b>356</b> of the release member <b>308</b> to provide an abutment or interference therebetween. Once a medical practitioner removes the removable cannula guard <b>324</b> from the needle assembly <b>330,</b> the release member <b>308</b> may be deployed as described herein.

0100As shown in <figref idref="f0021 f0022"><b>FIGS. 37-38</b></figref><b>,</b> the removable cannula guard <b>324</b> may include a tapered portion <b>328</b> having a contour for allowing a medical practitioner to more easily grip the removable cannula guard <b>324</b> for removal from the needle assembly <b>330.</b> In another embodiment, the removable cannula guard <b>324</b> may have a reinforcing tube <b>348</b> disposed within the interior of the removable cannula guard <b>324</b> and structured to at least partially surround the cannula <b>334.</b> The reinforcing tube <b>348</b> may also include fastening means <b>362</b> for removeably securing the removable cannula guard <b>324</b> to the hub <b>364</b> of the needle assembly <b>330.</b> In one embodiment, the fastening means <b>362</b> can include corresponding friction-fit or press-fit structures. In another embodiment, the fastening means <b>362</b> can include corresponding threaded structures for mating engagement allowing a medical practitioner to remove the removable cannula guard <b>324</b> from the needle assembly <b>330</b> by rotational movement of the removable cannula guard <b>324</b> with respect to the housing <b>332.</b>

0101<figref idref="f0023 f0024 f0025 f0026 f0027 f0028 f0029 f0030 f0031 f0032 f0033 f0034"><b>FIGS. 39-58</b></figref> illustrate yet another embodiment of a needle assembly <b>530</b> of the present invention. <figref idref="f0023"><b>FIGS. 39</b></figref><b>,</b><figref idref="f0024"><b>41</b></figref><b>,</b><figref idref="f0025"><b>43</b></figref><b>,</b><figref idref="f0026"><b>45</b></figref><b>,</b> and <figref idref="f0027"><b>47</b></figref> each illustrate the needle assembly <b>530</b> with a removable cannula guard <b>512</b> which must be removed prior to use of the needle assembly <b>530,</b> as previously described. The removable cannula guard <b>512</b> may include a tab portion <b>512a</b> structured to prevent depression of the release member <b>508.</b> In this embodiment, the tab portion <b>512a</b> is designed to provide an abutment or interference between the release member <b>508</b> and the safety shield <b>536,</b> as previously described.

0102The needle assembly <b>530</b> generally includes a cannula <b>534</b> associated with a portion of the housing <b>532,</b> such as a hub <b>564</b> for supporting at least a portion of the cannula <b>534,</b> and/or a specimen collection container holder <b>578.</b> The needle assembly also generally includes a safety shield <b>536</b> adapted for safety shielding the cannula <b>534</b> during and/or after use of the needle assembly <b>530</b>. The needle assembly <b>530</b> further includes a flash chamber <b>598</b> within at least a part of the housing <b>532,</b> as previously described.

0103In one embodiment, the needle assembly <b>530</b> includes a first portion <b>538,</b> with a secondary portion <b>540</b> connected to the first portion <b>538.</b> The secondary portion <b>540</b> defines an interior <b>542</b> structured to receive the specimen collection container, such as an evacuated blood collection tube (not shown) therein. In one embodiment, the secondary portion <b>540</b> is a specimen collection container holder <b>578.</b> In another embodiment, the secondary portion <b>540</b> is a blood collection container holder <b>578</b> and the needle assembly <b>530</b> is a blood collection assembly <b>530.</b>

0104In one embodiment, the secondary portion <b>540</b> includes an arcuate proximal end <b>544.</b> As shown specifically in <figref idref="f0024"><b>FIGS. 41-42</b></figref><b>,</b> the side portions of the arcuate proximal end <b>544</b> each define a generally concave proximal region <b>546</b> and, as shown specifically in <figref idref="f0025"><b>FIGS. 43-44</b></figref><b>,</b> the top and bottom portions of the arcuate proximal end <b>544</b> each define a generally convex proximal region <b>548</b> separated by the generally concave proximal regions <b>546</b> of the side portions. Optionally, the exterior surface <b>550</b> of the secondary portion <b>540</b> may include opposing ridged areas <b>552</b> for allowing a medical practitioner to easily grasp the secondary portion <b>540.</b> In one embodiment, the opposing ridged areas <b>552</b> may be made of a tacky elastomeric material.

0105The distal end <b>554</b> of the secondary portion <b>540</b> may also include an engagement mechanism <b>556</b> for engaging the first portion <b>538.</b> In one embodiment, the distal end <b>554</b> of the secondary portion <b>540</b> includes at least one recess <b>558,</b> shown in <figref idref="f0027"><b>FIGS. 47-48</b></figref><b>,</b> for mating engagement with a protrusion <b>560</b> integral with the proximal end <b>562</b> of the first portion <b>538.</b> The first portion <b>538</b> and the secondary portion <b>540</b> may be secured together by a press-fit locking mechanism, a threaded screw mechanism, a bayonet mechanism, or may be adhered together through the use of conventional adhesives. Optionally, the exterior surface <b>566</b> of the first portion <b>538</b> may also include opposing ridged areas <b>568</b> for allowing a medical practitioner to easily grasp the first portion <b>538.</b> The cannula <b>534</b> may be positioned in part within the interior <b>42</b> of the secondary portion <b>540</b> and in part within the interior <b>570</b> of the first portion <b>538,</b> as previously described.

0106Optionally, the secondary portion <b>540</b> of the present embodiment can include at least one tube preload indicator <b>572</b> for indicating to a medical practitioner the appropriate depth to which a specimen collection container, such as an evacuated blood tube, can be inserted without accessing the interior of the evacuated blood tube, such as by penetration of the cannula <b>534.</b> Optionally, a portion of the cannula <b>534</b> may be protected by a pierceable sleeve <b>582</b> disposed about the proximal end of the cannula <b>534</b>. In one embodiment, the preload indicator <b>572</b> may be a raised or recessed band disposed within the interior or exterior surface of the secondary portion <b>540,</b> such as within an interior or exterior surface of the sidewall of the secondary portion <b>540.</b> Alternatively, the preload indicator <b>572</b> can be a colored or textured band within the interior or exterior of the secondary portion <b>540.</b> In another embodiment, the preload indicator <b>572</b> can be a continuous or segmented band. In this manner, an evacuated blood collection tube can be "pre-loaded" into the needle assembly <b>530</b> prior to use.

0107In one embodiment, the hub <b>564</b> at least partially supports the cannula <b>534,</b> as previously described. The hub <b>564,</b> including rear hub portion <b>574</b> and forward hub portion <b>576,</b> is desirably molded from a transparent or translucent polymeric material or resin. As such, the hub <b>564,</b> and in particular forward hub portion <b>576,</b> defines a flash chamber <b>598.</b> In one embodiment, the rear hub portion <b>574</b> engages the forward hub portion <b>576</b> through a portion of the secondary portion <b>540</b> of the housing <b>532</b> to form a sealed flash chamber <b>598.</b> In this configuration, the flash chamber <b>598</b> can be formed by introduction of the rear hub portion <b>574</b> through the interior <b>542</b> of the secondary portion <b>540</b> for engagement with a portion of the forward hub portion <b>576</b> disposed within the interior <b>570</b> of the first portion <b>538.</b> The housing <b>532</b> may include a forward hub portion <b>576</b> and a rear hub portion <b>574</b> connectable with the forward hub portion <b>576</b> and defining the flash chamber therebetween. In one embodiment, a protrusion <b>580</b> of the rear hub portion <b>574</b> extends through the secondary portion <b>540</b> of the housing <b>532</b> and matingly engages a corresponding recess within the forward hub portion <b>576.</b> Accordingly, in one configuration, the rear hub portion <b>574</b> is connectable with the forward hub portion <b>576</b> through at least a portion of a specimen collection container holder <b>578,</b> shown in <figref idref="f0023"><b>FIG. 39</b></figref><b>.</b> In another configuration, the rear hub portion <b>576</b> defines a specimen collection container receiving port <b>504</b> therein, shown in <figref idref="f0032"><b>FIG. 55</b></figref><b>.</b>

0108As shown in <figref idref="f0028"><b>FIG. 49</b></figref><b>,</b> in one embodiment at least a portion of the rear hub portion <b>574</b> is restrained within the interior <b>542</b> of the secondary portion <b>540,</b> such that a portion of the flash chamber <b>598</b> may be formed within the secondary portion <b>540,</b> such as within a blood collection tube holder. In another embodiment, the flash chamber <b>598</b> can be formed at least partially within the forward hub portion <b>576</b> and at least partially within rear hub portion <b>574.</b> In this configuration, a slim profile of the needle assembly <b>530</b> can be maintained while increasing the volume of the interior of the flash chamber <b>598</b> visible to a medical practitioner when the safety shield <b>536</b> is in the retracted position.

0109As shown in <figref idref="f0028"><b>FIG. 49</b></figref><b>,</b> in one embodiment, the void <b>598a</b> formed between the forward hub portion <b>538</b> and the rear hub portion <b>540</b> may allow for the compression of air therein, thereby creating sufficient pressure to force fluid, such as blood, entering the cannula <b>534</b> to be forced into the flash chamber <b>598.</b> In one embodiment, the void <b>598a</b> is sized to accommodate a sufficient volume of compressed air to force blood entering the cannula <b>534</b> into the flash chamber <b>598.</b>

0110Transition of the safety shield from the retracted position, shown in <figref idref="f0023"><b>FIG. 39</b></figref> with the removable cannula guard <b>512</b> in place, to the extended position, shown in <figref idref="f0023"><b>FIG. 40</b></figref><b>,</b> may be effected as previously described. In one embodiment, a spring <b>584</b> disposed between a portion of the safety shield <b>536</b> and a portion of the housing <b>532</b> biases the safety shield <b>536</b> toward the extended position. In another embodiment, a release member <b>508,</b> such as a push button, may actuate the transition of the safety shield <b>536</b> from the retracted position to the extended position, as previously described. Alternatively, the release member <b>508</b> may initiate an activator to transition the safety shield <b>536</b> from the retracted position to the extended position, also as previously described.

0111During transition of the safety shield <b>536</b> from the retracted position to the extended position, the spring <b>584</b> advances the safety shield <b>536</b> from a position at least partially within the first portion <b>538</b> of the housing <b>532</b> to a location distal from the distal region <b>586</b> of the first portion <b>538,</b> as shown in <figref idref="f0025"><b>FIGS. 43-44</b></figref><b>.</b> In this embodiment, the safety shield <b>536</b> is adapted to move between the retracted position, in which at least the puncture tip of the patient end <b>588</b> of the cannula <b>534</b> is exposed for accessing the patient, and the extended position in which the puncture tip of the patient end <b>588</b> of the cannula <b>534</b> is encompassed or otherwise safely shielded from exposure. It is noted that although <figref idref="f0023"><b>FIGS. 39</b></figref><b>,</b><figref idref="f0024"><b>41</b></figref><b>,</b><figref idref="f0025"><b>43</b></figref><b>,</b><figref idref="f0026"><b>45</b></figref><b>,</b> and <figref idref="f0027"><b>47</b></figref> each show the removable cannula guard <b>512</b> disposed over the cannula <b>534</b> in the retracted position, the removable cannula guard <b>512</b> is removed prior to use of the needle assembly <b>530,</b> in which the cannula <b>534</b> is exposed.

0112As shown in <figref idref="f0025"><b>FIG 44</b></figref><b>,</b> in the extended position, the safety shield <b>536</b> is retained within the distal region <b>586</b> of the first portion <b>538</b> by the engagement of proximal rim <b>590</b> of the safety shield <b>536</b> against distal restraint <b>592</b> of the first portion <b>538.</b> As shown in <figref idref="f0027"><b>FIG. 48</b></figref><b>,</b> also in the extended position, the safety shield <b>536</b> is prevented from re-entering the first portion <b>538</b> of the housing <b>532,</b> beyond the engagement at the distal region <b>586,</b> by the engagement of the proximal rim <b>590</b> of the safety shield <b>536</b> and the barrier mechanism <b>594</b> of the first portion <b>538</b> of the housing <b>532.</b>

0113As shown in <figref idref="f0027"><b>FIGS. 48</b></figref><b>,</b> the barrier mechanism <b>594</b> may include a locking tab <b>596</b> that is deflectable upon transition of the safety shield <b>536</b> from the retracted to the extended position, but substantially resists deflection once the safety shield <b>536</b> is in the extended position. The locking tab <b>596</b> may include a tapered surface <b>528</b> which allows the safety shield <b>536</b> to advance thereover due to the applied force of spring <b>584</b> during transition from the retracted position to the extended position. The locking tab <b>596</b> may also include a stopped surface <b>526</b> to prevent the safety shield <b>536</b> from passing over the locking tab <b>596</b> once transition from the retracted position to the extended position has occurred. Therefore, the safety shield <b>536</b> of the needle assembly <b>530</b> remains locked in place over the cannula <b>534</b> once the safety shield <b>536</b> has been transitioned from the retracted position to the extended position.

0114As shown in <figref idref="f0030"><b>FIGS. 51-52</b></figref><b>,</b> an alternative locking tab <b>596a</b> may be included within the needle assembly <b>530.</b> The locking tab <b>596a</b> includes a similar geometry as described above, permitting transition of the safety shield <b>536</b> thereover by deflection when the shield <b>536</b> is transitioned from the retracted position to the extended position, and substantially resisting axial deflection once the shield <b>536</b> has been transitioned to the extended position. As shown in <figref idref="f0030"><b>FIG. 52</b></figref><b>,</b> a portion of the housing <b>532</b> may be disposed about the locking tab <b>596a</b> to substantially resist deflection in the radial direction as shown by the arrow <b>B</b> in <figref idref="f0030"><b>FIG. 52</b></figref><b>.</b>

0115As shown in <figref idref="f0031 f0032"><b>FIGS. 53-55</b></figref><b>,</b> during assembly of the present embodiment, the cannula <b>534</b> may be joined with the forward hub portion <b>576</b> and the rear hub portion <b>574</b> to form hub <b>564</b> haying a flash chamber <b>598</b> therein, with the cannula <b>534</b> in fluid communication with the interior of the flash chamber <b>598.</b> A spring <b>584</b> may be disposed between the forward hub portion <b>576</b> and a portion of the safety shield <b>536.</b> The safety shield <b>536</b> may be inserted within an interior of a second housing portion <b>532a</b> through a portion of the release member <b>508.</b> As shown in <figref idref="f0031"><b>FIG. 53</b></figref><b>,</b> a portion of the housing <b>536</b> may include a joining mechanism <b>522</b> for engaging a corresponding tab <b>524</b> on the hub <b>564</b> to engage the hub <b>564</b> with a second housing portion <b>532a.</b> As shown, locking tabs <b>596a</b> may be provided within a distal end of the second housing portion <b>532a.</b> When the hub <b>564</b> and the second housing portion <b>532a</b> are joined, the shield <b>536</b> is biased toward the extended position by the spring <b>584.</b> However, the release element <b>508</b> restrains the bias of the spring in the first position by engaging a shoulder <b>514</b> of the safety shield <b>536</b> and the restraining portion <b>520</b> of the release member <b>508.</b> As shown in <figref idref="f0031 f0032"><b>FIGS. 53-55</b></figref><b>,</b> assembly of the release member 508 may be accomplished for a proximal or rearward direction, however, it is also contemplated herein that assembly may be directed from an upwardly direction, as shown in <figref idref="f0038"><b>FIGS. 65-66</b></figref><b>,</b> or from a distally or frontward direction.

0116As shown in <figref idref="f0033"><b>FIG. 56</b></figref><b>,</b> the hub <b>564</b> may be formed by engaging the forward hub portion <b>576</b> with the rear hub portion <b>574.</b> The cannula <b>534</b> may be engaged with and partially supported by at least one of the forward hub portion <b>576</b> and the rear hub portion <b>574.</b> A porous plug <b>510</b> may be disposed between the forward hub portion <b>576</b> and the rear hub portion <b>574</b> within the flash chamber <b>598</b> defined therebetween and in fluid communication with the cannula <b>534.</b>

0117As shown in <figref idref="f0033 f0034"><b>FIGS. 57-58</b></figref><b>,</b> a needle assembly <b>530</b> may include a non-patient needle <b>516</b> (or the non-patient end of the cannula) having a pierceable sleeve <b>582</b> disposed thereover and may be aligned with the patient needle <b>518</b> through the flash chamber <b>598</b> defined within the hub <b>564.</b> A spring <b>584</b> may be disposed between the forward hub portion <b>576</b> and a portion of the safety shield <b>536.</b> The safety shield <b>536</b> may be inserted within an interior of a second housing portion <b>532a</b> through a portion of the release member <b>508.</b> The combined safety shield <b>536,</b> second housing portion <b>532a,</b> hub <b>564,</b> and cannula <b>534</b> may be inserted within a third housing portion <b>532b,</b> such as a specimen collection container holder or a blood collection tube holder.

0118It is anticipated herein that the hub <b>564,</b> cannula <b>534,</b> safety shield <b>536,</b> and second housing portion <b>532a</b> may be integrally provided within a third housing portion <b>532b,</b> such as a blood collection tube holder. Alternatively, hub <b>564,</b> cannula <b>534,</b> safety shield <b>536,</b> and second housing portion <b>532a</b> may be provided as a non-integral arrangement in which the hub <b>564</b> may include a specimen collection container receiving port <b>504,</b> shown in <figref idref="f0032"><b>FIG. 55</b></figref><b>,</b> adapted for later engagement with a specimen collection container.

0119As shown in <figref idref="f0035 f0036 f0037"><b>FIGS. 59-63</b></figref><b>,</b> the non-integrated needle assembly <b>630</b> is similarly structured to the embodiments described above. In one embodiment, the forward hub portion <b>674</b> and the rear hub portion <b>676</b> are joined, such as permanently joined, via a weld adjacent the outer circumference <b>678</b> of the hub <b>664.</b> The flash chamber <b>698</b> may be formed between the forward hub portion <b>674</b> and the rear hub portion <b>676.</b> In another embodiment, at least one of the forward hub portion <b>674</b> and the rear hub portion <b>676</b> are formed, such as molded, from a transparent or translucent polymeric material or resin. Accordingly, the flash chamber <b>698</b> may be visible to a medical practitioner through the hub <b>664.</b>

0120A first housing portion <b>632a</b> may be disposed about at least a portion of the forward hub portion <b>674</b> and the safety shield <b>636</b> and removable cannula guard <b>612</b> may be disposed about the patient end <b>640</b> of the cannula <b>634</b> and engaged with the first housing portion <b>632a,</b> as previously described. A distal cannula guard <b>646</b> may be provided for at least partially surrounding the non-patient end <b>642</b> of the cannula <b>634,</b> prior to use. The distal cannula guard <b>646</b> may engage at least a portion of the first housing portion <b>632a</b> and can be removed therefrom upon application of typical manual pressure. Both the distal cannula guard <b>646</b> and the removable cannula guard <b>612</b> are provided to shield the non-patient end <b>642</b> of the cannula <b>634</b> (or non-patient needle) and the patient end <b>640</b> of the cannula <b>634</b> (or patient needle) from accidental contact with medical practitioners prior to initiation of a medical procedure.

0121The rear hub portion <b>676</b> further includes a specimen collection container engagement port <b>656,</b> shown in <figref idref="f0036"><b>FIGS. 61</b></figref> and <figref idref="f0037"><b>63</b></figref><b>,</b> which is engageable with a specimen collection container holder <b>652</b> (as shown in <figref idref="f0037"><b>FIG. 64</b></figref>), such as a blood collection tube holder. In another embodiment, the specimen collection container engagement port <b>656</b> is directly engageable with a specimen collection container, such as an evacuated blood collection tube. It is further contemplated herein, that a flash chamber similar to the configuration shown in <figref idref="f0028"><b>FIG. 49</b></figref> with reference to <b>598,</b> may be employed within the present design.

0122As shown in <figref idref="f0038"><b>FIGS. 65-66</b></figref><b>,</b> an additional mechanism <b>668</b> of the needle assembly <b>630</b> is shown. In this embodiment, the release member <b>608</b> is adapted to transition from a first position to a second position, as previously described. Release member <b>608</b> further includes a projection <b>610</b> which deforms at least a portion of the housing <b>632,</b> such as tab portion <b>638</b> adjacent the release member <b>608,</b> when the release member is transitioned from the first position to the second position. Deformation of the tab portion <b>638</b> of the housing <b>632</b> restrains the release member <b>608</b> in the second position, thereby preventing the release member <b>608</b> from returning to the first position.

0123<figref idref="f0039 f0040 f0041"><b>FIGS. 67-72</b></figref> depict another embodiment of the present invention, in which collection assembly <b>730,</b> is similarly constructed to the above-described embodiments, with the exception of the configuration of safety shield <b>736</b> and the attachment of safety shield <b>736</b> to the housing <b>732.</b> Needle assembly <b>730</b> generally includes a cannula <b>734,</b> associated with the housing <b>732,</b> such as supported by a hub <b>764,</b> as previously described. A flash chamber <b>798</b> is associated with a portion of the housing <b>732,</b> such as defined within the hub <b>764.</b>

0124In the embodiment shown in <figref idref="f0039 f0040 f0041"><b>FIGS. 67-72</b></figref><b>,</b> the safety shield <b>736</b> may include a first portion <b>710,</b> such as an arm portion, and a second portion <b>712,</b> such as a shield portion, with the second portion <b>712</b> connected to the first portion <b>710.</b> The first portion <b>710</b> is configured to slideably engage a portion of the housing <b>732</b> along the longitudinal axis <b>L,</b> shown in <figref idref="f0041"><b>FIG. 71</b></figref><b>,</b> of the cannula <b>734</b> when a medical practitioner applies typical manual force to the safety shield <b>736</b> substantially in the direction shown by arrow <b>C.</b> In one embodiment, the first portion <b>710</b> is configured to slideably engage, such as glide along, a glide mechanism <b>714</b> integral with the housing <b>732.</b> In another embodiment, a portion of the housing <b>732</b> and a portion of the safety shield <b>736</b> define an engaging glide mechanism <b>714,</b> wherein a portion of the safety shield <b>736</b> is axially transitionable with respect to a portion of the housing <b>732.</b>

0125In one embodiment, the first portion <b>710</b> includes a protrusion <b>718</b> for slideably engaging a groove <b>720</b> recessed into a portion of the exterior surface <b>716</b> of the housing <b>732,</b> thereby establishing a glide mechanism <b>714.</b> In another embodiment, the first portion <b>710</b> includes a recess for slideably engaging a protrusion extending above the exterior surface <b>716</b> of the housing <b>732.</b> The first portion <b>710</b> may include a grip region <b>722</b> for receiving the finger of a medical practitioner to aid in the advancement of the safety shield <b>736</b> from the retracted position, shown in <figref idref="f0039"><b>FIG. 67</b></figref><b>,</b> to the extended position, shown in <figref idref="f0039"><b>FIG. 68</b></figref> along the glide mechanism <b>714.</b>

0126The second portion <b>712</b> of the safety shield <b>736</b> is adapted to at least partially surround, such as circumferentially surround, a portion of the hub <b>764</b> disposed at least partially within the housing <b>732</b> when the shield <b>736</b> is in the retracted position, such that the flash chamber <b>798</b> defined therein, is at least partially visible to a medical practitioner when the safety shield <b>736</b> is in the retracted position. In one embodiment, at least a portion of the flash chamber <b>798</b> is visible to a medical practitioner through an observation window <b>724</b> or cutaway portion within the second portion <b>712</b> of the safety shield <b>736.</b> In another embodiment, the second portion <b>712</b> of the safety shield <b>736</b> may be constructed of a transparent material and/or translucent material, such that the flash chamber <b>798</b> may be visible therethrough.

0127In this embodiment, the safety shield <b>736</b> is adapted to move between a retracted position, as shown in <figref idref="f0039"><b>FIG. 67</b></figref><b>,</b> in which at least the puncture tip of the patient end <b>740</b> of the cannula <b>734</b> is exposed for accessing the patient, and an extended position, shown in <figref idref="f0039"><b>FIG. 68</b></figref><b>,</b> in which the puncture tip of the cannula <b>734</b> is encompassed or otherwise safely shielded from exposure. The second portion <b>712</b> of the safety shield <b>736</b> is adapted to at least partially surround, such as circumferentially surround, at least a portion of the cannula <b>734</b> in the extended position. In another embodiment, the patient end <b>740</b> of the cannula <b>734</b> is at least partially surrounded by the second portion <b>712</b> of the safety shield in the extended position.

0128The safety shield <b>736</b> may be deployed over the cannula <b>734</b> while the cannula <b>734</b> is accessing the interior of the patient's blood vessel (not shown), or after the cannula <b>734</b> has been removed from the patient. If the transition of the safety shield <b>736</b> from the retracted position to the extended position occurs while the cannula <b>734</b> is accessing the interior of a patient's blood vessel, the distal portion <b>744</b> of the safety shield <b>736,</b> such as of the second portion <b>712</b> of the safety shield <b>736,</b> will contact the patient's skin. In one embodiment, the safety shield <b>736</b> includes a detent mechanism to temporarily restrain the safety shield <b>736</b> in a retracted position and a locking mechanism <b>750</b> adapted to maintain the safety shield <b>736</b> in the extended position after it is moved thereto. As shown in <figref idref="f0041"><b>FIG. 71</b></figref><b>,</b> the first portion <b>710</b> of the safety shield <b>736</b> may include a locking mechanism <b>750</b> which is deflected or otherwise radially biased against a portion of the housing <b>732,</b> such as by a portion of the first portion <b>710,</b> when the safety shield <b>736</b> is in the retracted position. As shown in <figref idref="f0041"><b>FIG. 72</b></figref><b>,</b> once the safety shield <b>736</b> is transitioned to the extended position, the locking mechanism <b>750</b> is advanced, such as longitudinally advanced along the longitudinal axis L of the cannula <b>734</b> until contact with the housing <b>732</b> is disrupted. At this point, the radially biasing forces maintaining the locking mechanism <b>750</b> in a substantially parallel orientation with respect to the cannula <b>734</b> are released, and the locking mechanism swings toward the cannula <b>734,</b> as shown by arrow <b>D,</b> to engage a distal end of the housing <b>732.</b> Once the locking mechanism <b>750</b> is engaged with the distal end of the housing <b>732,</b> retraction of the safety shield <b>736</b> from the extended position to the retracted position is prevented.

0129An alternative needle assembly <b>830</b> having a glideable safety shield <b>836</b> is shown and described with reference to <figref idref="f0042 f0043 f0044 f0045 f0046 f0047 f0048 f0049"><b>FIGS. 73-86</b></figref><b>.</b> In this configuration, the needle assembly <b>830</b> generally includes a cannula <b>834</b> associated with a portion of the housing <b>832,</b> and a safety shield <b>836</b> adapted for safety shielding of the cannula <b>834</b> during and/or after use of the device. A proximal portion <b>838</b> of the interior of housing <b>832</b> may be configured to receive an evacuated blood collection tube (not shown) therein and may include an interior ridge <b>840,</b> as shown in <figref idref="f0044"><b>FIG. 76</b></figref><b>,</b> for limiting the advancement of the evacuated blood collection tube through the proximal portion <b>838</b> of the housing <b>832.</b>

0130The cannula <b>834,</b> may include a distal patient needle <b>44</b> (or a patient end of a single cannula) and a proximal non-patient needle <b>46</b> (or a non-patient end of a single cannula). The proximal non-patient needle <b>46</b> may be provided for puncturing of an evacuated blood collection tube (not shown). Distal patient needle <b>44</b> may be beveled to define a puncture tip for puncturing the skin of a patient and accessing the patient's vasculature. The cannula <b>834</b> is supported by at least a portion of the housing <b>832,</b> such as a hub portion <b>864.</b> A flash chamber <b>898</b> may be defined within the hub <b>864</b> as previously described. In one embodiment, the hub <b>864</b> and the cannula <b>834</b> can be integrally formed with the remainder of the housing <b>832.</b> Alternatively, the hub <b>864</b> and/or the cannula <b>834</b> can be separately formed and subsequently assembled.

0131In the embodiment shown in <figref idref="f0042 f0043 f0044 f0045 f0046 f0047 f0048 f0049"><b>FIGS. 73-86</b></figref><b>,</b> the safety shield <b>836</b> may include a first portion <b>810,</b> such as an arm portion, and a second portion <b>812,</b> such as a shield portion. The first portion <b>810</b> and the second portion <b>812</b> are connected. The first portion <b>810</b> may include a grip portion <b>814</b> for receiving the finger of a medical practitioner to aid in the advancement of the safety shield <b>836</b> from the retracted position in which the patient end <b>44</b> is exposed, shown in <figref idref="f0044 f0045 f0046"><b>FIGS. 75-79</b></figref><b>,</b> to the extended position in which the patient end <b>44</b> is shielded, shown in <figref idref="f0047 f0048 f0049"><b>FIGS. 82-86</b></figref><b>.</b>

0132The safety shield <b>836</b> is configured to slideably engage a portion of the hub <b>864</b> along a glide mechanism <b>816</b> established by the interface of an upper surface <b>820</b> of the hub <b>864</b> and a lower surface <b>818</b> of the safety shield <b>836,</b> such as a lower surface of the second portion <b>812</b> of the safety shield <b>836.</b> The interface of the upper surface <b>820</b> and the lower surface <b>818</b> may be provided as a frictional slide between the two surfaces. Alternatively, the upper surface <b>820</b> may be provided with a protrusion (not shown), as previously described, for receipt within a corresponding groove (not shown), as previously discussed, within a portion of the lower surface <b>818.</b> Alternatively, the upper surface <b>820</b> may be provided with a groove (not shown) for receipt of a protrusion (not shown) extending from a portion of the lower surface <b>818.</b>

0133In one embodiment, the first portion <b>810</b> of the shield <b>836</b> may slideably engage a portion of the hub 864 along the longitudinal axis <b>T</b> (shown in <figref idref="f0044"><b>FIG. 75</b></figref>) of the cannula <b>834.</b> As shown in <figref idref="f0045"><b>FIG. 77</b></figref><b>,</b> the first portion <b>810</b> of the shield <b>836</b> may have a first end <b>850</b> which slideably engages a portion of the hub <b>864,</b> such that the lower surface <b>818</b> of the shield <b>836</b> slideably engaged the upper surface <b>820</b> of the hub <b>864.</b> The first portion <b>810</b> of the shield <b>836</b> may also have a second end <b>852,</b> shown in <figref idref="f0045"><b>FIGS. 77-78</b></figref><b>,</b> extending at least partially through a portion of the housing <b>832.</b> In another embodiment, the second end <b>852</b> of the first portion <b>810</b> may extend at least partially through a portion of the outer surface <b>856</b> of the housing <b>832.</b> In yet another embodiment, as shown in <figref idref="f0044"><b>FIG. 75</b></figref><b>,</b> the second end <b>852</b> of the first portion <b>810</b> extends at least partially through a groove <b>858</b> defined in the outer surface <b>856</b> of the housing <b>832.</b> The groove <b>858</b> may extend within the housing <b>832</b> substantially along the longitudinal axis T of the cannula <b>834.</b> The first portion <b>810</b> of the shield <b>836</b> may slide within the groove <b>858</b> as the shield <b>836</b> is transitioned from the retracted position to the extended position. In another embodiment, as shown in <figref idref="f0043"><b>FIG. 74</b></figref><b>,</b> the first portion <b>810</b> may have a contoured surface <b>868</b> that substantially corresponds to a distal contoured surface <b>870</b> of the housing <b>832.</b>

0134The second portion <b>812</b> of the safety shield <b>836</b> is adapted to at least partially surround, such as circumferentially surround, at least a portion of the hub <b>864</b> in the retracted position. In one embodiment, the second portion <b>812</b> is disposed about a portion of the cannula <b>834</b> and axially aligned with a portion of the first portion <b>810</b> to transition about the cannula <b>834</b> from the retracted position to the extended position.

0135The safety shield <b>836</b> may also be prevented from unintentional advancement from the housing <b>832,</b> prior to initiation by a medical practitioner, by the resistance engagement of a portion of the shield <b>836</b> with a portion of the housing <b>832</b> and/or hub <b>864.</b> Upon application of force by a medical practitioner to the grip portion <b>814</b> in the direction shown by arrow <b>R</b> in <figref idref="f0045"><b>FIG. 77</b></figref><b>,</b> the safety shield <b>836</b> is advanced in a distal direction along the longitudinal axis T, shown in <figref idref="f0044"><b>FIG. 75</b></figref><b>,</b> from the housing <b>832.</b>

0136With reference to <figref idref="f0046"><b>FIGS. 79</b></figref> and <figref idref="f0049"><b>86</b></figref><b>,</b> the safety shield <b>836</b> may include restraining means <b>874</b> for preventing transition of the shield <b>836</b> from the extended position to the retracted position, once the shield <b>836</b> has been transitioned from the retracted position to the extended position. During transition of the safety shield <b>836</b> from the retracted position to the extended position, a proximal protrusion <b>876</b> of the safety shield <b>836</b> is advanced through a restraint notch <b>878</b> within the housing <b>832</b> and/or hub <b>864,</b> such as within the glide mechanism <b>816.</b>

0137The restraint <b>notch 878</b> may include a triangular portion <b>880</b> structured to allow the proximal protrusion <b>876</b> of the safety shield <b>836</b> to easily pass therethough, and a restraining surface <b>882</b> structured to prevent re-entry of the proximal protrusion <b>876</b> of the safety shield <b>836</b> once the transition of the safety shield <b>836</b> from the retracted position to the extended position has occurred. In this manner, once the safety shield <b>836</b> has shielded the patient end <b>844</b> of the cannula <b>834,</b> the safety shield <b>836</b> may not re-enter the housing <b>832.</b>

0138In one embodiment, the flash chamber <b>898</b> is at least partially visible to a medical practitioner when the safety shield <b>836</b> is in the retracted position. Accordingly, a portion of the shield <b>836,</b> such as the second portion <b>812,</b> may be constructed of a transparent material and/or translucent material, such that the flash chamber <b>898</b> may be visible therethrough.

0139<figref idref="f0050 f0051 f0052 f0053 f0054"><b>FIGS. 87-91</b></figref> depict another embodiment of the present invention, in which collection assembly <b>930</b> is constructed as similarly described above, with the exception of the configuration of safety shield <b>936</b> and the attachment of safety shield <b>936</b> to the housing <b>932.</b> Needle assembly <b>930</b> generally includes cannula <b>934</b> associated with the housing <b>932,</b> and a safety shield <b>936</b> adapted for safety shielding of the cannula <b>934</b> during and/or after use of the device. Needle assembly <b>930</b> further includes a hub <b>964</b> for supporting the cannula <b>934</b> and defining a flash chamber <b>998,</b> as previously described, therein.

0140In the embodiment shown in <figref idref="f0050 f0051 f0052 f0053 f0054"><b>FIGS. 87-91</b></figref><b>,</b> a safety shield <b>936</b> includes a depending arm <b>940</b> attached to the exterior surface <b>942</b> of the housing <b>932.</b> The depending arm <b>940</b> may include a plurality of extendable segments <b>948,</b> such as first extendable segment <b>944</b> connected to second extendable segment <b>950.</b> In one embodiment, the first extendable segment <b>940</b> may be pivotally or hingedly connected, such as by a pivot <b>956,</b> to the base portion <b>952</b> of the depending arm <b>940,</b> allowing the first extendable segment <b>944</b> to articulate with respect to the base portion <b>952.</b> In another embodiment, the second extendable segment <b>950</b> may be pivotally or hingedly connected, such as by a pivot <b>956,</b> to the first extendable segment <b>944,</b> allowing the second extendable segment <b>950</b> to articulate with respect to the first extendable segment <b>944.</b>

0141In one embodiment, the depending arm <b>940</b> of the shield <b>936</b> is oriented on a first side of the cannula <b>934.</b> In another embodiment, the shield <b>936</b> includes a second depending arm <b>970,</b> as similarly described, oriented on a second side of the cannula <b>934,</b> with the second side being substantially opposite the first side. In a further embodiment, the depending arm <b>940</b> and the second depending arm <b>970</b> may be connected, such as by a union <b>972.</b> In another embodiment, the depending arm <b>940</b> and the second depending arm <b>970</b> may be connected by at least one pivot <b>956.</b> In a further embodiment, a pivot <b>956</b> may provide for an articulation of less than 180 degrees.

0142In one embodiment, the orientation of the depending arm <b>940</b> and the second depending arm <b>970</b> provides for the flash chamber <b>998</b> to be easily viewed when the shield is in the retracted position. In the retracted position, as shown in <figref idref="f0050"><b>FIG. 87</b></figref><b>,</b> the extendable segments <b>948</b> are oriented in a substantially lateral orientation, such that a distal alignment end <b>976</b> of the first extendable segment <b>944</b> is spaced apart from a proximal alignment end <b>978</b> of the second extendable segment <b>950.</b> In one embodiment, the distal alignment end <b>976</b> of the first extendable segment <b>944</b> is offset or positioned within a distinct longitudinal plane from the proximal alignment end <b>978</b> of the second extendable segment <b>950</b> in the lateral orientation. In a further embodiment, at least one of the distal alignment end <b>976</b> of the first extendable segment <b>944</b> and the proximal alignment end <b>978</b> of the second extendable segment <b>950</b> are offset from the transition axis <b>W</b> of the shield <b>936</b> in the lateral orientation.

0143The safety shield <b>936</b> may be transitioned from the retracted position to the extended position by the application of manually applied force to the release member <b>982</b> in the direction as shown by arrow <b>H,</b> shown in <figref idref="f0050"><b>FIG. 87</b></figref><b>.</b> In the partially extended position, as shown in <figref idref="f0051"><b>FIG. 88</b></figref><b>,</b> the forward urging of the base portion <b>952</b> initiates the first extendable segment <b>944</b> to articulate about the pivot <b>956</b> until a proximal end <b>960</b> reaches the apex position (shown in <figref idref="f0051"><b>FIG. 88</b></figref>). As shown in <figref idref="f0052"><b>FIG. 89</b></figref><b>,</b> movement of the first extendable segment <b>944</b> advances the second extendable segment <b>950</b> through pivot <b>956.</b> Such movement may be accomplished by continued forward movement of release member <b>982</b> in the direction of arrow <b>H,</b> shown in <figref idref="f0050"><b>FIG. 87</b></figref><b>,</b> which causes movement of the base portion <b>952,</b> which in turn articulates the first extendable segment <b>944.</b> Alternatively, the extendable segments <b>948</b> may be constructed of a material having resiliency, so as to effect automatic movement once the first extendable segment <b>944</b> reaches an apex, thereby creating a mechanism for automatic continued movement. In order to accommodate this motion, the free end 986 of the second extendable segment 950 is advanced along the transition axis W, shown in <figref idref="f0050">FIG. 87</figref>.

0144In the fully extended position, as shown in <figref idref="f0054">FIG. 91</figref>, the first extendable segment 944 and the second extendable segment 950 are oriented in a substantially parallel orientation with respect to each other along substantially the same longitudinal plane as the cannula 934 in shielding orientation of the cannula 934. In the fully extended position the extendable segments 948 are substantially longitudinally oriented, such that a distal alignment end 976 of the first extendable segment 944 is substantially adjacent the proximal alignment end 978 of the second extendable segment 950. In one embodiment, the distal alignment end 976 of the first extendable segment 944 contacts the proximal alignment end 978 of the second extendable segment 950 along the same longitudinal plane W, as shown in <figref idref="f0054">FIG. 91</figref>.

0145The safety shield 936, specifically the first extendable segment 944 and the second extendable segment 950, may have any suitable dimensions and configuration such that they are adapted to shield the cannula 934, and in particular the puncture tip thereof, when the safety shield 936 is in the extended position. The safety shield 936 may be deployed over the cannula 934 while the cannula 934 is accessing the interior of the patient's blood vessel (not shown), or after the cannula 934 has been removed from the patient. A locking mechanism, as similarly described herein, may further be employed to prevent transition of the shield 936 from the extended position to the retracted position once the shield 936 has been transitioned from the retracted position to the extended position.

0146In one embodiment, the flash chamber 998 may be visible to medical practitioners in both the retracted position and the extended position, as well as in the partly extended position. In another embodiment, transition of the safety shield 936 from the retracted position to the extended position is accomplished without obstructing the view of the flash chamber 998. In this configuration, articulation of the safety shield 936 occurs remotely from the viewpath of the flash chamber 998. For example, the pivots 956 may be positioned on the bottom portion of needle assembly 930, so as not to obstruct a direct top-line view of the flash chamber 998 by a medical practitioner.

0147<figref idref="f0055">FIGS. 92-93</figref> depict another embodiment of the present invention, in which needle assembly 1030 is similarly as described above, with the exception of the configuration of safety shield <b>1036</b> and the attachment of safety shield <b>1036</b> to the housing <b>1032.</b> Needle assembly <b>1030</b> generally includes a cannula <b>1034</b> associated with the housing <b>1032,</b> and a safety shield <b>1036</b> adapted for safety shielding of the cannula <b>1034</b> during and/or after use of the device. Needle assembly <b>1030</b> further includes a hub <b>1064</b> for supporting the cannula <b>1034</b> and defining a flash chamber <b>1098</b> therein, as previously described. At least a portion of the hub <b>1064</b> and the flash chamber <b>1098</b> are visible through a portion of the safety shield <b>1036</b> in the retracted position.

0148In one embodiment, the shield <b>1036</b> includes a depending arm <b>1006</b> transitionable from a first position, shown in <figref idref="f0055"><b>FIG. 92</b></figref><b>,</b> in which the depending arm <b>1006</b> is substantially perpendicular to the longitudinal axis S of the cannula <b>1034</b> (shown in <figref idref="f0055"><b>FIG. 92</b></figref>), to a second position, shown in <figref idref="f0055"><b>FIG. 93</b></figref><b>,</b> in which the depending arm is substantially oriented along the longitudinal axis <b>S</b> of the cannula <b>1034.</b> In one embodiment, the depending arm <b>1006</b> may include a first portion <b>1008</b> and a second portion <b>1010</b> pivotally or hingedly connected therebetween.

0149A portion of the shield <b>1036</b> is adapted to at least partially surround, such as circumferentially surround, at least a portion of the tip of the cannula <b>1034</b> in the extended position shown in <figref idref="f0055"><b>FIG. 93</b></figref><b>.</b> In one embodiment, the flash chamber <b>1098</b> is at least partially visible to a medical practitioner when the safety shield <b>1036</b> is in the retracted position. In the retracted position, the first portion <b>1008</b> and the second portion <b>1010</b> are oriented in a substantially perpendicular orientation with respect to the axis of the cannula <b>1034,</b> and substantially parallel to each other in the extended position. The shield may further include a circular portion <b>1088</b> disposed circumferentially about a portion of the cannula <b>1034.</b> In one embodiment, once the first portion <b>1008</b> and the second portion <b>1010</b> are aligned in substantially parallel orientation, the circular portion <b>1088</b> may be advanced over the depending arm <b>1006,</b> such as over the hinge <b>1090</b> connecting the first portion <b>1008</b> and the second portion <b>1010,</b> thereby locking the hinge <b>1090</b> in place.

0150In another embodiment, shown in <figref idref="f0056 f0057 f0058 f0059 f0060 f0061 f0062 f0063 f0064"><b>FIGS. 94-106</b></figref><b>,</b> another alternative hinged assembly embodiment of the present invention is shown. Needle assembly <b>30c1</b> generally includes needle structure <b>32c1</b> associated with needle holder <b>42c1,</b> and a safety shield <b>64c1</b> adapted for safety shielding of the needle structure <b>32c1</b> after use of the device. Needle assembly <b>30c1</b> further includes a hub <b>58c1</b> for supporting the needle structure <b>32c1</b> and a flashback indicator <b>60c1</b> defined therein, as previously described.

0151In the embodiment shown in <figref idref="f0056 f0057 f0058 f0059 f0060 f0061 f0062 f0063 f0064"><b>FIGS. 94-106</b></figref><b>,</b> the safety shield <b>64c1</b> may include a first depending arm <b>3000</b> and a second depending arm <b>3002</b> substantially parallel to the first depending arm <b>3000.</b> The first depending arm <b>3000</b> and the second depending arm <b>3002</b> are connected together by a connection surface <b>3004</b> that is substantially perpendicular to the first depending arm <b>3000</b> and the second depending arm <b>3002.</b> The safety shield <b>64c1</b> has a proximal end <b>3006</b> adjacent the needle holder <b>42c1</b> and a distal end <b>3008</b> opposed from the proximal end <b>3006.</b> At least a portion of the proximal end <b>3006</b> of the safety shield <b>64c1</b> is pivotally connected to the needle holder <b>42c1.</b> Preferably, the proximal end <b>3006</b> of the safety shield <b>64c1</b> is connected to the needle holder <b>42c1</b> by two opposing pivots <b>3010.</b> In a further embodiment, the safety shield <b>64c1</b> is pivotally connected to the front cone <b>3012</b> of the needle holder <b>42c1</b> by pivots <b>3010</b> extending through opposing attachment arms <b>3014</b> connected to the front cone <b>3012</b> and oriented along the longitudinal axis of the needle holder <b>42c1.</b>

0152The pivot(s) <b>3010</b> allow the safety shield <b>64c1</b> to transitionally pivot in a rotational manner with respect to the needle holder <b>42c1</b> from a retracted position, as shown in <figref idref="f0059 f0060 f0061"><b>FIGS. 98</b>-<b>101</b></figref> to an extended position, as shown in <figref idref="f0062 f0063"><b>FIGS. 102-104</b></figref><b>.</b> In one embodiment, the safety shield <b>64c1</b> may also include a shield engaging area <b>3016</b> within the connection surface <b>3004</b> adjacent the proximal end <b>3006</b> having a contour substantially corresponding to the contour of the exterior surface <b>3018</b> of the needle holder <b>42c1</b> and/or the exterior surface <b>3018</b> of the front cone <b>3012.</b> In this configuration, the shield engaging area <b>3016</b> may rest against a portion of the needle holder <b>42c1</b> in the retracted position.

0153As shown in <figref idref="f0058"><b>FIG. 97</b></figref><b>,</b> the hub <b>58c1</b> may include a front hub portion <b>3026</b> and a rear hub portion <b>3028</b> joined to the first hub portion <b>3026.</b> The front hub portion <b>3026</b> may have a substantially conical shape disposed about the flashback indicator <b>60c1.</b> In one embodiment, at least a portion of the front hub portion <b>3026</b> extends distally beyond the front cone <b>3012</b> of the needle holder <b>42c1.</b> In another embodiment, at least a portion of the front hub portion <b>3026</b> has a contour that corresponds to a contour of the front cone <b>3012</b> of the needle holder <b>42c1.</b> The rear hub portion <b>3028</b> of the hub <b>58c1</b> may include a disk structure dimensioned to contact an interior perimeter of the needle holder <b>42c1</b> to prevent advancement of an evacuated blood collection tube (not shown) therebeyond. At least a portion of the needle structure <b>32c1</b> may extend through the front hub portion <b>3026</b> and the rear hub portion <b>3028</b> of the hub <b>58c1.</b> Although the hub <b>58c1</b> may be provided within the collection assembly as an integral element, in an alternative configuration, the hub <b>58c1,</b> including the front hub portion <b>3026</b> and the rear hub portion <b>3028,</b> as well as the needle structure <b>32c1</b> may be separately formed and subsequently assembled within the collection assembly <b>30c1.</b>

0154In one embodiment, the needle assembly <b>30c1</b> may be provided with a removable IV needle shield <b>3020</b> covering at least a portion of the needle structure <b>32c1</b>, such as covering at least a portion of the distal needle portion <b>34c1</b>. In one embodiment, as shown in <figref idref="f0058"><b>FIG. 97</b></figref><b>,</b> the needle shield <b>3020</b> can be sized to extend over at least a portion of the front hub portion <b>3026</b> of the hub <b>58c1,</b> the front cone <b>3012</b> of the needle holder <b>42c1,</b> the flashback indicator <b>60c1,</b> and/or the hub <b>58c1.</b> The needle shield <b>3020</b> can be removed from the needle assembly <b>30c1</b> prior to use by typical manual applied pressure.

0155Referring again to <figref idref="f0058"><b>FIG. 97</b></figref><b>,</b> in another embodiment the needle shield <b>3020</b> can be provided with a raised protrusion <b>3022</b> disposed on the exterior surface <b>3024</b> of the needle shield <b>3020.</b> In one embodiment, the raised protrusion <b>3022</b> is circumferentially disposed about the needle shield <b>3020.</b> In another embodiment, the raised protrusion <b>3022</b> corresponds to a notch <b>3030</b> within the safety shield <b>64c1</b> such that the needle shield <b>3020</b> cannot be accidentally released from the needle assembly <b>30c1</b> until the safety shield <b>64c1</b> is positioned in the retracted position, as shown in <figref idref="f0059 f0060 f0061"><b>FIGS. 98-101</b></figref><b>.</b>

0156The safety shield <b>64c1</b> can be sized to have any dimensions suitable to allow the safety shield <b>64c1</b> to be pivoted away from the needle structure <b>32c1</b> in the retracted position, as shown in <figref idref="f0059 f0060 f0061"><b>FIGS. 98-101</b></figref><b>,</b> to allow a medical practitioner to engage the needle structure <b>32c1</b> with a patient, and to pivot toward and shield the needle structure <b>32c1,</b> specifically the tip of the distal needle portion <b>34c1</b> in the extended position, as shown in <figref idref="f0062 f0063"><b>FIGS. 102-104</b></figref><b>.</b> In one embodiment, the safety shield <b>64c1</b> may be pivoted away from the axis of the needle structure <b>32c1</b> to a sufficient angle to allow a medical practitioner to view the flashback indicator <b>60c1</b> and/or hub <b>58c1</b> in the retracted position. In another embodiment, the safety shield <b>64c1</b> is made of a transparent and/or translucent material to allow a medical practitioner to view the flashback indicator <b>60c1</b> and/or hub <b>58c1</b> therethrough.

0157Once the distal needle portion <b>34c1</b> has been removed from the patient, the needle assembly <b>30c1</b> may be transitioned from the retracted position to the extended position. In one embodiment, the first depending arm <b>3000</b> and the second depending arm <b>3002</b> of the safety shield <b>64c1</b> may be constructed to form a press-fit lock with at least a portion of the front hub portion <b>3026,</b> the front cone <b>3012</b> and/or the needle holder <b>42c1.</b> This prevents the safety shield <b>64c1</b> from re-transitioning to the retracted position once the initial transition from the retracted position to the extended position has occurred. As shown in <figref idref="f0064"><b>FIGS. 105-</b></figref><b>106,</b> the first depending arm <b>3000</b> and the second depending arm <b>3002</b> may each include an inwardly angled restraint <b>3032</b> disposed adjacent the pivot <b>3010</b> at the proximal end <b>3006</b> of the safety shield <b>64c1</b>. The angled restraint <b>3032</b> includes a sloped surface <b>3036</b> and a restraining surface <b>3038.</b> The front hub portion <b>3026</b> may also include a plurality of ledges <b>3034</b> for engaging the angled restraints <b>3032.</b> In one embodiment, when the safety shield <b>64c1</b> of the needle assembly <b>30c1</b> is transitioned from the retracted position to the extended position, the angled restraint <b>3032</b> of the safety shield <b>64c1</b> engages the ledge(s) <b>3034</b> of the front hub portion <b>3026.</b> Specifically, the restraining surface 3038 engages the ledge(s) <b>3034</b> and prevents subsequent movement of the safety shield <b>64c1</b>. In one embodiment, the ledge(s) <b>3034</b> are positioned on the distal end <b>3050</b> of the hub <b>58c1.</b> In another embodiment, the angled restraint(s) <b>3032</b> are positioned on the safety shield <b>64c1</b> at a location distal from the pivot(s) <b>3010</b> for correspondingly engaging the ledge(s) <b>3034</b> on the distal end <b>3050</b> of the hub <b>58c1.</b> Alternatively, the front cone <b>3012</b> may also include a plurality of ledges <b>3034a</b> for engaging the angled restraint <b>3032</b> of the safety shield <b>64c1</b>. In yet another embodiment, the angled restraint(s) <b>3032</b> are positioned on the superior side <b>3052</b> of the safety shield <b>64c1</b> and may extend in a direction proximal from the pivot(s) <b>3010.</b> Accordingly, the engagement of the safety shield <b>64c1</b> and the hub <b>58c1</b> may occur at the superior side <b>3052</b> (bottom side), of the needle assembly <b>30c1.</b> Transition of the angled restraint <b>3032</b> over the ledge(s) <b>3034</b> can be effectuated with typical manual pressure. As shown in <figref idref="f0064"><b>FIG. 106</b></figref><b>,</b> the safety shield <b>64c1</b> may optionally include a biasing element <b>3040</b> for further securing the front hub portion <b>3026</b> within the safety shield <b>64c1</b>. Thus, the locking structure of the safety shield <b>64c1</b> engages at least a portion of the flash chamber, defined within the hub <b>58c1.</b> In one embodiment, the locking structure of the safety shield <b>64c1</b> engages at least a portion of the housing, such as the hub <b>58c1,</b> at a location distal to the flash chamber.

0158<figref idref="f0065 f0066 f0067 f0068 f0069 f0070 f0071 f0072 f0073 f0074 f0075"><b>FIGS. 107-121</b></figref> depict yet another alternative hinged assembly embodiment of the present invention. A needle assembly <b>5000,</b> as shown in <figref idref="f0065 f0066 f0067 f0068 f0069"><b>FIGS. 107-113</b></figref><b>,</b> generally includes a needle structure <b>32c2</b>, associated with a hub <b>58c2,</b> and a safety shield <b>64c2</b> connected to the hub <b>58c2</b> and adapted for safety shielding of the needle structure <b>32c2</b> after use of the device. In one embodiment, the needle assembly <b>5000</b> may incorporate features of other known needle assemblies having hinged safety shields, such as those disclosed in United States Patent Publication No. 2005/0187493, the entire disclosure of which is hereby incorporated by reference.

0159The needle structure <b>32bc2</b> may include a distal needle portion <b>5002</b> and a proximal needle portion <b>5004.</b> Distal needle portion <b>5002</b> and proximal needle portion <b>5004</b> may be separate needles, both of which represent needle cannulae defining central lumen <b>5006</b> extending therethrough. The proximal needle portion <b>5004</b> represents a non-patient end of the needle structure <b>32bc2,</b> which is provided for puncturing of an evacuated blood collection tube (not shown). The proximal needle portion <b>5004</b> may be covered by an elastomeric multiple sample sleeve <b>5008</b> that can be pierced by a pointed end of proximal needle portion <b>5004</b> of the needle structure <b>32c2.</b> Distal needle portion <b>5002</b> represents a patient end of the needle structure <b>32c2,</b> and may be beveled to define a puncture tip for puncturing the skin of a patient and accessing the vasculature of the patient.

0160The hub <b>58c2</b> may include a front hub portion <b>5010</b> and a rear hub portion <b>5012</b> and is capable of supporting the needle structure <b>32c2</b> therethrough. In one embodiment, the distal needle portion <b>5002</b> may be integral with the front hub portion <b>5010</b> and the proximal needle portion <b>5004</b> may be integral with the rear hub portion <b>5012.</b> The front hub portion <b>5010</b> and the rear hub portion <b>5012</b> are structured to matingly engage. The front hub portion <b>5010</b> may include a protrusion <b>5014,</b> such as a raised annular ring, for engaging a corresponding recess <b>5016</b> integral to the rear hub portion <b>5012.</b> In another embodiment, the front hub portion <b>5010</b> and the rear hub portion <b>5012</b> may be joined together via an adhesive or weld.. Once assembled, the hub <b>58c2</b> defines a flashback indicator <b>60c2</b> therein, as previously described.

0161The hub <b>58c2</b> may further include a collar <b>5018</b> for surrounding at least a portion of the safety shield <b>64c2,</b> such as a pivot <b>5020</b> of the safety shield <b>64c2,</b> as previously described herein. In one embodiment, the front hub portion <b>5010</b> includes a first collar portion <b>5022</b> and the rear hub portion <b>5012</b> includes a second collar portion <b>5024.</b> The first collar portion <b>5022</b> may include a generally c-shaped region <b>5028</b> for accommodating an attachment bearing <b>5026</b> of the safety shield <b>64c2,</b> shown in <figref idref="f0069"><b>FIGS. 112</b></figref> and <figref idref="f0070"><b>114</b></figref><b>,</b> therein. The attachment bearing <b>5026</b> may be integral with the safety shield <b>64c2.</b> The attachment bearing <b>5026</b> may also be integral with a portion of the hub <b>58c2,</b> such as the first collar portion <b>5022</b> and/or the second collar portion <b>5024.</b> Alternatively, the attachment bearing <b>5026</b> may be separately provided and subsequently assembled with the safety shield <b>64c2</b> and/or the hub <b>58c2.</b> The attachment bearing <b>5026</b> can extend between a first depending arm <b>5044</b> and a second depending arm <b>5046</b> of the safety shield <b>64c2,</b> as shown in <figref idref="f0071"><b>FIG. 115</b></figref><b>.</b> The second collar portion <b>5024</b> may include a cap region <b>5030</b> having an interior surface <b>5032</b> substantially corresponding to the attachment bearing <b>5026</b> of the safety shield <b>64c2.</b> The first collar portion <b>5022</b> may include a protrusion <b>5034</b> for engaging a corresponding recess <b>5036</b> integral to the second collar portion <b>5024.</b> Accordingly, in one embodiment, the engagement of the front hub portion <b>5010</b> with the rear hub portion <b>5012</b> also engages the first collar portion <b>5022</b> with the second collar portion <b>5024.</b> In another embodiment, the collar <b>5018</b> is positioned substantially on a top surface of the hub <b>58c2</b> to allow the safety shield <b>64c2</b> to likewise be connected to the top surface of the hub <b>58c2.</b>

0162Referring again to <figref idref="f0065 f0066 f0067 f0068 f0069"><b>FIGS. 107-113</b></figref><b>,</b> a proximal IV needle shield <b>5038</b> and a distal IV needle shield <b>5040</b> can be respectively provided over the proximal needle portion <b>5004</b> and the distal needle portion <b>5002</b> prior to use, as described herein.

0163During use, the proximal IV needle shield <b>5038</b> can be removed from the proximal needle portion <b>5004</b> and the needle holder <b>42c2,</b> shown in <figref idref="f0071 f0072 f0073 f0074 f0075"><b>FIGS. 115-121</b></figref><b>,</b> can be inserted over the proximal needle portion <b>5004</b> and engaged with at least a portion of the hub <b>58c2.</b> In one embodiment, the needle holder <b>42c2</b> is engaged with a portion of the rear hub portion <b>5012.</b>

0164In another embodiment, shown in <figref idref="f0070"><b>FIG. 114</b></figref><b>,</b> the attachment bearing <b>5026</b> of the safety shield <b>64c2</b> may include a notch <b>5042</b> for retaining the safety shield <b>64c2</b> within a specified location. For example, the notch <b>5042</b> may frictionally retain the safety shield <b>64c2</b> within the collar <b>5018</b> at a specified angle in the retracted position. This allows a medical practitioner to position the safety shield <b>64c2</b> at a desired angle during a medical procedure without attending to accidental closure or slippage of the safety shield <b>64c2.</b>

0165As shown in <figref idref="f0071 f0072 f0073 f0074 f0075"><b>FIGS. 115-121</b></figref><b>,</b> the needle assembly <b>30c2</b> can be transitioned from the retracted position, shown in <figref idref="f0070"><b>FIG 114</b></figref><b>,</b> in which the distal needle portion <b>5002</b> is unshielded for the purpose of accessing a patient, to the extended position, in which the distal needle portion <b>5002</b> is safety shielded from exposure, as described herein. With reference to <figref idref="f0065 f0066 f0067 f0068 f0069 f0070 f0071 f0072 f0073 f0074 f0075"><b>FIGS. 107-121</b></figref><b>,</b> in another embodiment, the safety shield <b>64c2</b> may include a thumb press-region <b>64c2a</b> for enabling a medical practitioner to pivot the safety shield <b>64c2</b> to engage a portion of the proximal IV shield <b>5038</b> prior to puncturing the skin of a patient. In one embodiment, the thumb press-region <b>64c2a</b> extends at least partially beyond the safety shield <b>64c2</b> to enable the medical practitioner to easily contact the thumb-press region <b>64c2a</b> with a single finger or thumb.

0166In an alternative embodiment, as shown in <figref idref="f0076"><b>FIG. 122</b></figref><b>,</b> a collection assembly <b>130w,</b> may include a safety shield <b>64w</b> may include a first end <b>138w</b> having a first depending arm <b>132w</b> and a second depending arm <b>134w</b> substantially parallel to the first depending arm <b>132w.</b> The first depending arm <b>132w</b> and the second depending arm <b>134w</b> may be connected together. The first depending arm <b>132w</b> and the second depending arm <b>134w</b> may have substantially the same area. The safety shield <b>64w</b> has an end <b>140w</b> that is connected to the needle holder <b>42w</b> by at least one pivot <b>142w.</b> Preferably, the end <b>140w</b> of the safety shield <b>64w</b> is connected to the needle holder <b>42w</b> by two pivots <b>142w.</b> Example pivoting mechanisms are described in <patcit id="pcit0013" dnum="US2005187493A"><text>United States Patent Publication No. 2005/187,493</text></patcit>, the entire content of which is herein incorporated by reference.

0167In one embodiment, the pivot <b>142w</b> may include a protrusion integrally formed with the second end <b>140w</b> of the safety shield <b>64w</b> and a corresponding recess defined in the distal end of the needle holder <b>42w.</b> In another embodiment, the pivot <b>142w</b> may include a recess defined within the second end <b>140w</b> of the safety shield <b>64w</b> and a corresponding recess defined within the distal end of the needle holder <b>42w.</b> In yet another embodiment, a first pivot <b>142w</b> can be disposed on a first side of the distal end of the needle holder <b>42w</b> and a second pivot <b>142w</b> can be disposed on a second side of the distal end of the needle holder <b>42w,</b> the first and second sides of the needle holder <b>42w</b> being substantially opposite each other. The pivot(s) <b>142w</b> allow the safety shield <b>64w</b> to pivot in a rotational manner with respect to the needle holder <b>42w</b> from a retracted position, as shown in <figref idref="f0076"><b>FIG. 122</b></figref> to an extended position, as previously described.

0168In yet another embodiment of the invention, shown in <figref idref="f0077"><b>FIGS. 123-125</b></figref><b>,</b> the needle assembly <b>1130</b> includes a specimen collection container holder <b>1101</b> having a pierceable or punctureable shield <b>1102</b> disposed over the proximal end <b>1103</b> of the specimen collection container holder <b>1101</b> to provide a sterile environment within the interior of the specimen collection container holder <b>1101</b> prior to use. In one embodiment, the pierceable or punctureable shield <b>1102</b> is made of a paper, polymeric, and/or thin metal film having perforated sections therein which may be pierced by standard manually applied pressure. In use, a medical practitioner may insert any conventionally known specimen collection container <b>1105,</b> such as a blood collection tube, into the proximal end <b>1103</b> of the specimen collection container holder <b>1101</b> through the pierceable or punctureable shield <b>1102.</b>

0169The needle assembly <b>1130</b> may then be used in any manner as previously described herein to perform a medical procedure and/or shield a cannula <b>1134</b> after use. After use, the pierceable or punctureable shield <b>1102</b> may remain attached to the specimen collection container holder <b>1101</b> to provide a clear indication of use of the needle assembly <b>1130.</b> Accordingly, a needle assembly <b>1130</b> including a pierceable or punctureable shield <b>1102</b> provides a clear tamper and/or use indicator to a medical practitioner. The pierceable or punctureable shield <b>1102</b> described herein is suitable for use with any of the above-described collection assemblies. It is further contemplated that a separate, removable liner (not shown) may be affixed, such as through a removable adhesive, over the outer surface of shield <b>1102.</b> Such a removable liner provides further sterility and barrier protection prior to the use. In addition, the pierceable or punctureable shield <b>1102</b> may be applied to the proximal end <b>1103</b> of the specimen collection container holder <b>1101</b> as a prepackaged device with the need for additional external packaging.

0170<figref idref="f0078 f0079 f0080 f0081"><b>FIGS. 126-131</b></figref> illustrate yet a further embodiment of the present invention in which the housing <b>7000</b> of a needle assembly, shown in <figref idref="f0080 f0081"><b>FIGS. 130-131</b></figref><b>,</b> as previously described herein, includes a base portion <b>7002,</b> shown in <figref idref="f0078"><b>FIGS. 126-127</b></figref><b>,</b> and a hub portion <b>7004,</b> shown in <figref idref="f0079"><b>FIGS. 128-129</b></figref><b>,</b> engageable with the base portion <b>7002.</b> Referring to <figref idref="f0078"><b>FIGS. 126-127</b></figref><b>,</b> the base portion <b>7002</b> has a distal end <b>7006</b> and a proximal end <b>7008</b> with a sidewall <b>7010</b> extending therebetween. In one embodiment, the sidewall <b>7010</b> defines at least one opening <b>7012</b> through which a first portion <b>7016</b> of the hub <b>7004,</b> shown in <figref idref="f0079"><b>FIG. 128</b></figref><b>,</b> may be received. In another embodiment, the opening <b>7012</b> is adapted to allow a first portion <b>7016</b> of the hub <b>7004,</b> to pass from an interior <b>7022</b> of the base portion <b>7002</b> through the sidewall <b>7010</b> to a position external to the interior <b>7022</b> of the base portion <b>7002.</b> In another embodiment, the sidewall <b>7010</b> defines a second opening <b>7014</b> through which a second portion <b>7018</b> of the hub <b>7004,</b> shown in <figref idref="f0079"><b>FIG. 128</b></figref><b>,</b> may be received. In yet another embodiment, the first opening <b>7012</b> of the base portion <b>7002</b> may be aligned in a substantially opposed orientation with respect to the second opening <b>7014,</b> such that the first opening <b>7012</b> and the second opening <b>7014</b> are aligned along a common through-axis <b>Z,</b> as shown in <figref idref="f0078"><b>FIG. 126</b></figref><b>.</b> In a further embodiment, the sidewall <b>7010</b> of the base portion <b>7002</b> may include a release member opening <b>7020</b> through which a release member <b>7040,</b> shown in <figref idref="f0080 f0081"><b>FIGS. 130-131</b></figref> and as previously described, may be received.

0171As shown in <figref idref="f0079"><b>FIGS. 128-129</b></figref><b>,</b> the hub <b>7004</b> may include a first portion <b>7016</b> extending in a substantially radial orientation from a body portion <b>7024</b> of the hub <b>7004.</b> In another embodiment, the hub <b>7004</b> may include a second portion <b>7018</b> extending in a substantially radial orientation from the body portion <b>7024</b> of the hub <b>7004</b> and aligned in a substantially opposed orientation with respect to the first portion <b>7016,</b> such that the first portion <b>7016</b> and the second portion <b>7018</b> are aligned at least partially along a common axis <b>Y,</b> as shown in <figref idref="f0079"><b>FIG. 128</b></figref><b>.</b> In another embodiment, the common axis <b>Y</b> of the hub portion <b>7004</b> may be alignable with the through-axis <b>Z</b> of the base portion <b>7002,</b> shown in <figref idref="f0078"><b>FIG. 126</b></figref><b>.</b>

0172As shown in <figref idref="f0080 f0081"><b>FIGS. 130-131</b></figref><b>,</b> the hub portion <b>7004</b> may be at least partially insertable within the base portion <b>7002</b> such that the first portion <b>7016</b> of the hub <b>7004</b> extends at least partially through the opening <b>7012</b> defined within the sidewall <b>7010</b> of the base portion <b>7002.</b> In another embodiment, the hub portion <b>7004</b> may be at least partially insertable within the base portion <b>7002</b> such that the first portion <b>7016</b> of the hub portion <b>7004</b> extends at least partially through the opening <b>7012</b> defined within the sidewall <b>7010</b> of the base portion <b>7002,</b> and the second portion <b>7018</b> of the hub extends at least partially through the second opening <b>7014</b> defined within the sidewall <b>7010</b> of the base portion <b>7002.</b> In yet another embodiment, the hub portion <b>7004</b> may be insertable into the interior <b>7022</b> of the base portion <b>7002</b> through the proximal end <b>7008.</b> In yet another embodiment, at least one of the first portion <b>7016</b> and the second portion <b>7018</b> are deflectable against an interior wall <b>7026</b> of the interior <b>7022</b> of the base portion, such as adjacent the proximal end <b>7008</b> during insertion of the hub portion <b>7004</b> into the base portion <b>7002.</b> In yet a further embodiment, at least one of the first portion <b>7016</b> and the second portion <b>7018</b> include a gripable region <b>7030</b> enabling a user to easily contact the housing <b>7000</b> when the hub portion <b>7004</b> is disposed within the base portion <b>7002.</b> In one embodiment, the gripable region <b>7030</b> includes a plurality of ribs <b>7032.</b>

0173While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The present embodiments described herein are meant to be illustrative only, and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof. Various other embodiments will be apparent to, and readily made by those skilled in the art, without departing from the scope and spirit of the invention.

0174Further aspects are: <ol id="ol0001"><li>1. A needle assembly, comprising: <ul id="ul0002" list-style="none" compact="compact"><li>a housing comprising a flash chamber, and having a distal end and a proximal end engageable with a specimen collection container;</li><li>a cannula having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior, the patient end of the cannula projecting at least partially from the distal end of the housing, the cannula interior in fluid communication with the flash chamber; and</li><li>a shield restrainably engaged with a portion of the housing and axially transitionable over the patient cannula from a retracted position in which the patient end is exposed, to an extended position in which the patient end is shielded by at least a portion of the shield, wherein at least a portion of the flash chamber is visible in the retracted position.</li></ul></li><li>2. The needle assembly of 1, wherein the flash chamber is visible through at least a portion of the shield in the retracted position.</li><li>3. The needle assembly of 2, wherein the portion of the shield through which the flash chamber is visible, is transparent or translucent.</li><li>4. The needle assembly of 1, wherein the shield comprises an observation window and the flash chamber is visible through the observation window in the retracted position.</li><li>5. The needle assembly of 4, wherein the patient end of the cannula has a bevel, and the position of the observation window within the shield corresponds to the orientation of the bevel.</li><li>6. The needle assembly of 1, wherein the proximal end of the housing defines a specimen collection container receiving port.</li><li>7. The needle assembly of 6, further comprising a removable seal disposed over a portion of the specimen collection container receiving port.</li><li>8. The needle assembly of 6, further comprising a rupturable seal disposed over a portion of the specimen collection container receiving port.</li><li>9. The needle assembly of 1, wherein the shield at least partially surrounds the patient end of the cannula in the extended position.</li><li>10. The needle assembly of 1, wherein the shield is substantially circumferentially disposed about at least a portion of the cannula, and transition of the shield from the retracted position to the extended position telescopes the shield over the cannula.</li><li>11. The needle assembly of 1, wherein the sidewall of the cannula defines an opening extending between the cannula interior and the flash chamber.</li><li>12. The needle assembly of 1, wherein the cannula comprises at least two distinct needle portions.</li><li>13. The needle assembly of 12, wherein the cannula comprises a patient needle in fluid communication with the flash chamber and a non-patient needle in fluid communication with the flash chamber.</li><li>14. The needle assembly of 13, wherein the patient needle projects at least partially from the distal end of the housing, and wherein the non-patient needle extends in a substantially proximal direction from the patient cannula.</li><li>15. The needle assembly of 1, wherein the flash chamber is integrally formed within a portion of the housing.</li><li>16. The needle assembly of 1, wherein the housing further comprises a hub supporting at least a portion of the cannula.</li><li>17. The needle assembly of 16, wherein the flash chamber is integrally formed with the hub.</li><li>18. The needle assembly of 1, wherein the specimen collection container is a blood collection container.</li><li>19. The needle assembly of 1, further comprising a porous vent disposed within the flash chamber, the porous vent separating the flash chamber into a first chamber and a second chamber.</li><li>20. The needle assembly of 19, wherein the first chamber and the second chamber are configured such that upon insertion of the patient end into a patient, blood flows through the cannula and into the first chamber without sealing the porous vent, and upon application of an evacuated specimen collection container to the non-patient end of the cannula, blood is drawn from the first chamber and air is drawn from the second chamber, thereby establishing a negative pressure within the second chamber with respect to an external environment of the flash chamber.</li><li>21. The needle assembly of 19, wherein the porous vent comprises a plurality of pores for passage of blood therethrough from the first chamber to the second chamber.</li><li>22. The needle assembly of 19, wherein the vent mechanism is at least one of a porous plug formed of a hydrophobic material, a one-way valve, and a porous plug formed of a hydrophilic material that swells on contact with blood.</li><li>23. The needle assembly of 1, wherein the flash chamber comprises a vent mechanism in communication with an external environment, surrounding the needle assembly.</li><li>24. The needle assembly of 1, wherein at least a shielding portion of the shield is restrainably engaged within an interior portion of the housing in the retracted position, and the shielding portion of the shield extends from the interior portion of the housing in the extended position.</li><li>25. The needle assembly of 4, wherein the interior portion of the housing is circumferentially disposed about a specimen collection container receiving port defined within the housing.</li><li>26. The needle assembly of 25, wherein the interior portion of the housing is co-axial with the specimen collection container receiving port.</li><li>27. The needle assembly of 1, wherein the housing comprises a first portion and a second portion, the first portion distal to the second portion, and wherein the shield is entirely disposed within an interior of the first portion in the retracted position, and a specimen collection container receiving port is defined within the second portion.</li><li>28. The needle assembly of 27, wherein the first portion and the second portion are co-formed.</li><li>29. The needle assembly of 27, wherein the first portion and the second portion are separately formed and subsequently assembled.</li><li>30. The needle assembly of 27, wherein the first portion of the housing defines an observation window through which the shield is visible when in the retracted position.</li><li>31. The needle assembly of 1, wherein the shield is biased against a portion of the housing by a spring when the shield is in the retracted position.</li><li>32. The needle assembly of 31, further comprising a release element transitionable from a first position to a second position, wherein the spring biases the shield to the extended position upon transition of the release element from the first position to the second position.</li><li>33. The needle assembly of 32, wherein the release element is a push button.</li><li>34. The needle assembly of 33, wherein the push button comprises a member oriented in a substantially perpendicular orientation with respect to a transition axis of the shield, and extending through at least a portion of the shield to maintain the shield against the bias of the spring in the first position.</li><li>35. The needle assembly of 34, wherein the member comprises a restraining portion and defines a passage region, the restraining portion engaging a shoulder of the shield in the restrained position, the shoulder of the shield passing through the passage region upon transition from the retracted position to the extended position.</li><li>36. The needle assembly of 35, wherein the passage region defines a substantially circular opening.</li><li>37. The needle assembly of 35, wherein the passage region defines a non-enclosed region.</li><li>38. The needle assembly of 35, further comprising a hub supporting at least a portion of the cannula, and wherein the restraining portion defines an interior region at least partially surrounding a portion of the hub.</li><li>39. The needle assembly of 32, further comprising a removable cannula guard engageable with a portion of the housing and removable prior to transition of the shield from the retracted position to the extended position, wherein a portion of the removable cannula guard prevents transition of the release element from the first position to the second position.</li><li>40. The needle assembly of 1, wherein at least one of a distal portion of the housing and a proximal portion of the shield comprise a barrier mechanism for preventing transition of the shield from the extended position to the retracted position.</li><li>41. The needle assembly of 40, wherein the barrier mechanism comprises a tamper-resistant flange</li><li>42. The needle assembly of 40, wherein the barrier mechanism comprises a locking tab deflectable upon transition of the shield from the retracted position to the extended position, and which substantially resists deflection once the shield is in the extended position.</li><li>43. The needle assembly of 42, wherein at least a portion of the housing surrounds a portion of the locking tab.</li><li>44. The needle assembly of 43, wherein the portion of the housing surrounding the locking tab substantially resists radial deflection of the locking tab.</li><li>45. The needle assembly of 1, wherein the shield comprises a first portion for slideably engaging a portion of the housing, and a second portion at least partially surrounding a portion of the cannula in the extended position.</li><li>46. The needle assembly of 45, wherein the first portion of the shield slideably engages an outer surface of the housing along the longitudinal axis of the cannula.</li><li>47. The needle assembly of 45, wherein the first portion of the shield comprises a protrusion for slideably engaging a groove recessed within a portion of the outer surface of the housing.</li><li>48. The needle assembly of 45, further comprising a glide mechanism comprising a portion of the housing and portion of the first portion of the shield, wherein a portion of the safety shield is axially transitionable with respect to a portion of the housing.</li><li>49. The needle assembly of 45, further comprising a hub disposed at least partially within a portion of the housing, and wherein the first portion of the shield slideably engages a portion of the hub along a longitudinal axis of the cannula.</li><li>50. The needle assembly of 49, wherein a first end of the first portion of the shield slideably engages a portion of the hub, and a second end of the first portion extends at least partially through a portion of an outer surface of the housing.</li><li>51. The needle assembly of 50, wherein the second end of the first portion extends at least partially through a groove defined in the outer surface of the housing and extending along the longitudinal axis of the cannula.</li><li>52. The needle assembly of 45, wherein the second portion of the shield surrounds at least a portion of the cannula.</li><li>53. The needle assembly of 45, wherein the shield is transitioned from the retracted position to the extended position by force applied to the first portion of the shield in the direction along a longitudinal axis of the cannula.</li><li>54. The needle assembly of 45, wherein the shield comprises restraining means for preventing transition of the shield from the extended position to the retracted position.</li><li>55. The needle assembly of 45, wherein the second portion of the shield comprises a depending arm transitionable from a first position in which the depending arm is substantially perpendicular to a longitudinal axis of the cannula, to a second position in which the depending arm is oriented substantially along the longitudinal axis of the cannula.</li><li>56. The needle assembly of 55, wherein the depending arm comprises a first portion and a second portion, the first portion and the second portion pivotally or hingedly connected to the first portion.</li><li>57. The needle assembly of 1, wherein the shield comprises a depending arm comprising a plurality of extendable segments, wherein the extendable segments are substantially laterally oriented in the retracted position and substantially longitudinally oriented in the extended position.</li><li>58. The needle assembly of 57, wherein the plurality of extendable segments are pivotally or hingedly connected therebetween.</li><li>59. The needle assembly of 57, wherein the depending arm is oriented on a first side of the cannula, and further comprising a second depending arm oriented on a second side of the cannula, the second side substantially opposite the first side.</li><li>60. A blood collection assembly, comprising: <ul id="ul0003" list-style="none" compact="compact"><li>a housing, comprising a flash chamber, having a distal end and a proximal end, and a blood collection container holder adjacent the proximal end;</li><li>a patient cannula having a cannula tip and defining a patient cannula interior, projecting at least partially from the distal end of the housing, the patient cannula interior in fluid communication with the flash chamber;</li><li>a non-patient cannula, defining a non-patient cannula interior, extending in a substantially proximal direction from the patient cannula within at least a portion of the blood collection container holder, the non-patient cannula interior in fluid communication with the flash chamber; and</li><li>a shield restrainably engaged with a portion of the housing and axially transitionable over the patient cannula from a retracted position, in which the patient end is exposed, to an extended position in which the cannula tip is shielded by at least a portion of the shield, wherein at least a portion of the flash chamber is visible in the retracted position.</li></ul></li><li>61. The blood collection assembly of 60, wherein the flash chamber is visible through at least a portion of the shield in the retracted position.</li><li>62. The blood collection assembly of 60, further comprising a removable or rupturable seal disposed over at least a portion of the blood collection container holder.</li><li>63. The blood collection assembly of 60, wherein the shield is biased against a portion of the housing by a spring in the retracted position, and further comprising a release element transitionable from a first position to a second position, wherein the spring transitions the shield to the extended position upon transition of the release element from the first position to the second position.</li><li>64. The blood collection assembly of 60, wherein the shield comprises a first portion for slideably engaging a portion of the housing along the longitudinal axis of the patient cannula, and a second portion at least partially surrounding a portion of the patient cannula in the extended position.</li><li>65. A needle assembly, comprising: <ul id="ul0004" list-style="none" compact="compact"><li>a housing, comprising a flash chamber, having a distal end, and a proximal end engageable with a specimen collection container;</li><li>a cannula having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior, the patient end of the cannula projecting at least partially from the distal end of the housing, the cannula interior in fluid communication with the flash chamber;</li><li>a shield restrainably engaged with a portion of the housing and axially transitionable over the patient cannula from a retracted position, in which the patient end is exposed, to an extended position, in which the patient end is shielded by at least a portion of the shield, wherein at least a portion of the flash chamber is visible in the retracted position;</li><li>a spring element biased between a portion of the housing and a portion of the shield in the retracted position; and</li><li>a release element transitionable from a first position to a second position, wherein the release element restrains the shield against the bias of the spring in the restrained position, and wherein transition of the release element from the first position to the second position transitions the shield from the retracted position to the extended position.</li></ul></li><li>66. The needle assembly of 65, wherein the release element is a push button.</li><li>67. The needle assembly of 65, wherein at least a portion of the flash chamber is visible through a portion of the shield in the retracted position.</li><li>68. The needle assembly of 65, wherein the proximal end of the housing comprises a blood collection container holder and the non-patient end of the cannula extends at least partially within an interior of the blood collection container holder.</li><li>69. A blood collection assembly, comprising: <ul id="ul0005" list-style="none" compact="compact"><li>a housing comprising a flash chamber, and having a distal end and a proximal end, and a blood collection container holder adjacent the proximal end;</li><li>a patient cannula having a cannula tip and defining a patient cannula interior, projecting at least partially from the distal end of the housing, the patient cannula interior in fluid communication with the flash chamber;</li><li>a non-patient cannula, defining a non-patient cannula interior, extending in a substantially proximal direction from the patient cannula within at least a portion of the blood collection container holder, the non-patient cannula interior in fluid communication with the flash chamber;</li><li>a shield restrainably engaged with a portion of the housing and axially transitionable over the patient cannula from a retracted position in which the cannula tip is exposed, to an extended position in which the cannula tip is shielded by at least a portion of the shield, wherein at least a portion of the flash chamber is visible through the shield in the retracted position;</li><li>a spring element biased between a portion of the shield and a portion of the housing in the retracted position; and</li><li>a push button engaged with a portion of the spring and transitionable from a first position to a second position, wherein the spring biases the shield to the extended position upon transition of the release element from the first position to the second position.</li></ul></li><li>70. A blood collection assembly, comprising: <ul id="ul0006" list-style="none" compact="compact"><li>a housing, comprising a flash chamber, having a distal end, and a proximal end engageable with a specimen collection container;</li><li>a cannula having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior, the patient end of the cannula projecting at least partially from the distal end of the housing, the cannula interior in fluid communication with the flash chamber; and</li><li>a shield, having an observation window, and engaged with a portion of the housing, the shield transitionable from a first position to a second position with respect to the housing, wherein the shield is disposed over the patient end in the second position, and wherein at least a portion of the flash chamber is viewable through the observation window in the first position.</li></ul></li><li>71. The blood collection assembly of 70, wherein the shield is axially transitionable over the cannula from a retracted position to an extended position.</li><li>72. The blood collection assembly of 70, wherein the shield is pivotally transitionable over the patient cannula from a retracted position to an extended position.</li><li>73. A blood collection assembly, comprising: <ul id="ul0007" list-style="none" compact="compact"><li>a housing, comprising a flash chamber, having a distal end, and a proximal end engageable with a specimen collection container;</li><li>a cannula having a patient end, a non-patient end, and a sidewall extending therebetween defining a cannula interior, the patient end of the cannula projecting at least partially from the distal end of the housing, the cannula interior in fluid communication with the flash chamber; and</li><li>a shield engaged with a portion of the housing and comprising a locking structure, the shield transitionable from a first position to a second position with respect to the housing, wherein the flash chamber is visible in the first position, and wherein the shield is disposed over the patient end of the cannula and the locking structure engages at least a portion of the flash chamber in the second position.</li></ul></li><li>74. The needle assembly of 1, wherein the housing comprises a base portion having a sidewall defining an opening, and a hub portion engageable with the base portion, wherein a portion of the hub portion is receivable through the opening.</li><li>75. The needle assembly of 74, wherein the sidewall of the base portion defines a first opening and a second opening aligned along a common axis, and the hub portion comprises a first portion and a second portion aligned along a common axis, wherein the first portion is receivable through the first opening and the second portion is receivable through the second opening.</li><li>76. The needle assembly of 75, wherein the hub portion is insertable within an interior of the base portion through a proximal end of the base portion, and wherein at least one of the first portion and the second portion are deflectable against a portion of an interior wall of the base portion during insertion of the hub portion into the base portion.</li><li>77. The blood collection assembly of 73, wherein the locking structure of the shield engages a portion of the housing distal to the flash chamber.</li><li>78. The needle assembly of 1, wherein the housing comprises a forward hub portion and a rear hub portion connectable with the forward hub portion and defining the flash chamber therebetween.</li><li>79. The needle assembly of 78, wherein the rear hub portion is connectable with the forward hub portion through at least a portion of a specimen collection container holder.</li><li>80. The needle assembly of 78, wherein the rear hub portion defines a specimen collection container receiving port therein.</li></ol>