Blood sampling device

BLOOD SAMPLING DEVICE

BLOOD SAMPLING DEVICE

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to an improved apparatus for arterial and venous blood sampling and, more particularly, to an improved blood sampling device for use in tapping a blood collection tube with reduced risk of accidental skin needle puncture to the operator.

A large variety of blood sampling devices are known. One of the early blood sampling techniques involves a reusable syringe. The needle of the syringe is inserted into one of the patient's blood vessels. Following insertion, the plunger of the syringe is partially withdrawn to create a vacuum in the syringe housing thereby drawing blood from the patient into the syringe housing. The needle is then removed from the blood vessel and the plunger is pushed forward so as to 'empty the syringe housing into a sample container which can then be sent to the laboratory for analysis.

The technique suffers from a number of disadvantages, related primarily to hygienic factors, and has been widely replaced with a more satisfactory technique wherein the syringe has been replaced with a housing which has no plunger but which features a needle sharpened at both ends and mounted near its mid-point at the anterior end of the housing. The posterior end of the housing is open. The device accommodates the insertion through its posterior end of sample containers sealed by septums, which containers have been previously put under vacuum.

In use, the anterior end of the device is inserted in one of the patient's blood vessels, as with a conventional syringe. An evacuated sampling container is then inserted 5 into the device and pushed forward sufficiently to allow the posterior end of the needle to pierce the septum and enter the sampling container. The vacuum in the container serves to draw blood into the sampling container. The device described is more hygienically acceptable and easily 10 accommodates the taking of multiple samples from a single needle puncture. Various improvements have been made on such devices. Illustrative of these are European Patent Application No. 88906129.7, and U.S. Patent Nos. 3,877,465 and 4,935,012.

While diagnostic blood sampling typically requires that a needle be inserted into one of the blood vessels of the patient, in certain situations it happens that a needle, originally inserted for a different purpose, is already in place in one of the patient's blood vessels. In 20 those situations it is desirable to use the existing needle to obtain the blood samples for diagnosis as well as for its original purpose.

Such is the case, for example, in the case of blood collections, where a relatively large quantity of blood is 25 collected from a donor. Before the donated blood may be safely used, it is necessary to check for blood type and that the blood does not contain certain dangerous components which could transmit such diseases as hepatitis and AIDS.

The sampling of the donated blood may be effected in a number of ways. One way involves taking a portion of the donated blood after the collection bag has been filled. 5 The disadvantages in this method are that it involves the risk of contaminating the blood supply and at the same time reduces the amount of usable donated blood. A further disadvantage is that the blood is mixed with the anticoagulant from the collection bag.

Another technique involves cutting the collection tube after the collection bag has been filled and allowing blood to flow into sampling containers. The risks here are that the blood may splash and come in contact with the skin of the operator and that open sampling containers will be 15 contaminated.

To avoid some of these problems, systems have been developed wherein the collection tube is made of at least two portions of tubing. One portion has an end which is connected to the collection bag and a second end which 20 contains a septum capable of accommodating a needle. The second portion has outwardly directed needles at both ends. One of the needles is used to pierce the patient's blood vessel while the other needle engages the septum described above. When the collection of blood has ended, blood 25 samples are collected by first disengaging the needle from the septum and then using the disengaged needle to pierce the septum of one or more closed sampling container so as to allow blood to flow into the sampling containers. A disadvantage of this technique is that in using the needle to pierce the various septums it is possible for the operator to accidentally puncture his or her skin with the contaminated needle.

Several improvements have been suggested to overcome these difficulties. Illustrative of these is European Patent Application No. 89307421.1, which discloses, for example, the placement of a tubular member around the needle connection to prevent, or at least to render more unlikely, the accidental puncturing by the needle of the skin of the operator.

Still, an inherent difficulty with this technique is that blood sampling must be performed either before or after, but not during, the collection of the blood. To overcome this limitation, a number of techniques have been developed which allow in-line sampling of a tube through which blood is flowing. Most of these techniques involve the use of various valves and spigots. A discussion of some of these, and their limitations and disadvantages, is presented in U.S. Pat. Nos. 4,763,648, 4,920,970 and 4,981,140 which are incorporated in their entirety by reference as if fully set forth herein.

In order to neatly overcome some of the above-stated disadvantages, U.S. Pat. Nos. 4,763,648, 4,920,970 and 4,981,140 to Wyatt disclose a novel device which makes it possible to draw blood samples from tubes through which blood is flowing without using complicated valve systems. One of the stated objects of the above-referenced inventions is to prevent accidental skin needle punctures. However, use of the disclosed device could, in certain cases still lead to the accidental puncture of the operator's skin, with the attendant potentially very serious risks to his or her health.

There is thus a widely recognized need for a device which would render in-line blood sampling devices, such as, but not limited to, those disclosed by Wyatt or similar to them, safer to use by making it virtually impossible for an operator to accidentally puncture his or her skin while taking blood samples from a blood flow line.

SUMMARY OF THE INVENTION . According to the present invention there is provided a protective device for use in conjunction with an in-line fluid sampling device in a fluid flow tube to protect against accidental puncture of the skin of the user, comprising: a housing having an open anterior end capable of fitting over the in-line fluid sampling device, and an open posterior end capable of accommodating the inlet end of a fluid sampling container, the housing having a means for fixing the position of the housing relative to the inline fluid sampling device the means being located near the anterior end of the housing; a support member extending radially inward from the inside surface of the housing at a location intermediate between the anterior end and posterior end of the housing; and a needle having sharpened anterior and posterior ends, attached to the support member so as to lie inside the housing along the centerline of the housing.

According to the present invention there is further provided an in-line fluid sampling apparatus for withdrawing fluid samples from a fluid flow tube, comprising: an in-line fluid sampling device, including: (1) a body having an upper and a lower chamber, the lower chamber having first and ־ second fluid ports in communication with the flow tube; and (2) sealing means carried by the upper chamber for sealing the lower chamber relative to atmosphere, the sealing means being penetrable by a needle to gain access to the lower chamber; and a protective device capable of fitting over the in-line fluid sampling device, including: (1) a housing having an open anterior end capable of fitting over the in-line fluid sampling device and an open posterior end capable of accommodating the inlet end of a fluid sampling container, the housing having a means for fixing the position of the housing relative to the in-line fluid sampling device the means being located near the anterior end of the housing; a support member extending radially inward from the inside surface of the housing at a location intermediate between the anterior end and the posterior end of the housing; and a needle having sharpened anterior and posterior ends, attached to the support member so as to lie inside the housing along the centerline of the housing, the anterior end of the needle piercing the sealing means carried by the upper chamber of the in-line fluid sampling device to gain access to the lower chamber whenever the means for fixing the position of the housing relative to the in-line fluid sampling device is engaged.

The present invention successfully addresses the shortcomings of the presently known configurations by providing an improved protective device for use in conjunction with an in-line fluid sampling device in a fluid flow tube to protect against accidental puncture of the skin of the user, and of a blood sampling device incorporating the protective device.

A protective device according to the present invention makes it possible to quickly and easily take blood samples from a blood flow line with virtually complete protection from accidental and potentially highly dangerous skin punctures.

A protective device according to the present invention is designed to be attachable to an in-line fluid sampling device, such as that described in U.S. Pat. Nos. 4,763,648, 4,920,970 and 4,981,140 to Wyatt, and similar devices. Protective devices according to the present invention feature a housing in which a needle is mounted in such a way that, upon attachment of the device to the fluid sampling device, one end of the needle comes in contact with the flowing fluid in the tube. The other end of the housing accommodates a sample container, preferably under vacuum, in such a way that, when the sample container is inserted into the housing, its cap is pierced by one end of the needle mounted in the housing, which piercing allows fluid to flow from the fluid line through the mounted needle and into the sample container.

The housing of the protective device is so shaped and sized as to make it very difficult for the user to accidentally puncture his skin with either end of the needle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic representation of a blood collection system equipped with an in-line blood sampling device;

FIG. 2 is a cross-sectional side view of a device according to the present invention;

FIG. 3 is a vacuum sampling container, such as a Vacutainer Brand;

FIG. 4 is a perspective partial cut-away view of a device according to the present invention;

FIG. 5 is a perspective partial cut-away view of an alternative embodiment of a device according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principles and operation of devices and apparatus according to the present invention can be better understood with reference to the figures which are included for illustrative purposes. While the present invention is applicable in the context of the sampling of any fluid, for convenience, and without in any way limiting the scope of the present invention, the descriptions which follows are limited to the sampling of blood.

Referring now to the drawings, Figure 1 shows a blood collection bag 10 of the type commonly used to collect donated blood. Connected to bag 10 is a tube 12 which is shown with some sections omitted. At one end, tube 12 is connected to bag 10. At the other end, tube 12 is connected to a blood vessel needle 14 capable of penetrating a blood vessel (not shown) of the patient.

At a convenient point along tube 12 which is intermediate between bag 10 and blood vessel needle 14, is located an in-line blood sampling device 16. In-line blood sampling device may be of any convenient design which makes it possible for a needle or similar object to enter tube 12 so as to draw out a portion of the blood flowing through tube 12. In particular, in-line blood sampling device 16 may be identical with or similar to that shown in Figure 1 of the present specification and which is described in detail in U.S. Pat. Nos. 4,763,648, 4,920,970 and 4,981,140 to Wyatt, which references are incorporated by reference in their entirety as if fully set forth herein.

In-line blood sampling device 16 preferably includes an upper chamber 20 and a lower chamber 22. Lower chamber 22 has two fluid ports 24 in communication with tube 12. Upper chamber 20 features sealing means 26, which is preferably a septum, at its upper surface. Sealing means 26 is capable of sealing lower chamber 22 relative to atmosphere. Sealing means 26 is penetrable by a needle to gain access to lower chamber 22.

In-line blood sampling device 16 preferably also includes gripping means 28 for gripping in-line fluid sampling device 16 between the thumb and a finger of the user.

Preferably, in-line blood sampling device 16 further includes shield means 30 preferably disposed between gripping means 28 and upper chamber 20 for protecting the thumb and finger of the user against accidental puncture by a needle during penetration of sealing means 26. Shield means 30 preferably includes a rigid member extending outwardly a substantial distance to substantially cover the thumb and the finger of the user.

Preferably, lower chamber 22 is constructed of a substantially transparent plastic and includes an interconnected bottom and side walls, with fluid ports 24 being formed in the side walls.

In-line blood sampling device 16 may be assembled in one of two basis ways. The manufacturer of blood sampling device 16 may thread device 16 onto an appropriate location in tube 12. To use an in-line blood sampling device 16 assembled through threading, requires that the sampling needle penetrate both sealing means 26 and the wall of tube

12.

Another way the manufacturer may assemble blood 5 sampling device 16 is to cut tube 12 at an appropriate location and proceed to glue, or otherwise attach, each of the cut ends of tube 12 to each of fluid ports 24. Use of an in-line blood sampling device 16 assembled through cutting and attaching tube 12, requires that the sampling 10 needle penetrate only sealing means 26 and not the wall of tube 12.

One possible configuration of a protective device 50 according to the present invention for use in conjunction with an in-line blood sampling device such as that 15 described above is shown in cross-section in Figure 2 and, in cutaway perspective format, in Figure 4.

Protective device 50 features a housing 52 having an open anterior end 54 and an open posterior end 56. Anterior end 54 is sufficiently large so as to be capable 20 of fitting over in-line fluid sampling device 16.

Posterior end 56 is sufficiently large as to be capable of accommodating the inlet end of a fluid sampling container 100 (Figure 3). The different size requirements are such that, in general, the sizes of anterior end 54 and of 25 posterior end 56 will be different from each other.

Preferably, housing 52 is cylindrical in shape. The different size requirements would generally result in a cylindrical housing 52 having two different diameters, as shown in Figures 2 and 4.

Housing 52 features a means for fixing the position of housing 52 relative to in-line fluid sampling device 16. The means for fixing the position can take on any of a 5 number of convenient forms. One such form, featuring specially shaped slots 58, is shown for illustration in Figures 2 and 4. Preferably, two such slots 58, located near anterior end 54 of housing 52 and spaced 180 degrees apart from each other, are used. Each slot 58 includes a 10 longitudinal and a tangential segment which are joined to approximately form a right angle.

In operation, the portions of tube 12 immediately adjoining in-line blood sample device 16 would be inserted into the longitudinal segments 58. Once tube 12 has been 15 fully inserted, protective device 50 would be rotated about its axis sufficiently to cause tube 12 to enter the tangential segments of slots 58. In this position, protective device 50 would be immobilized relative to tube 12. The act of fixing the position of protective device 50 20 simultaneously causes the insertion of the needle into inline blood sampling device, as will be described below.

Extending radially inward from the inside surface of housing 52 at a convenient location intermediate between anterior end 54 and posterior end 56 of housing 52 is a 25 support member 60. A needle 62 is attached to support member 60 so as to lie completely inside housing 52, preferably along the centerline of housing 52. The ends of needle 62 lie sufficiently far from the open ends of housing 52 as to make it very difficult for a user to accidentally pierce his skin with needle 62.

Needle 62 is mounted in such a way that when housing 52 is fully engaged with tube 12 the anterior end of needle 5 62 penetrates in-line blood sampling device 16 so as to communicate with the blood flowing in tube 12.

In a first alternative embodiment, shown in Figure 5, the anterior end 65 of needle 62 is blunt, rather than sharpened. The absence of a sharpened end at the anterior 10 end 65 of needle 62 further reduces the risks of accidental punctures of the skin. To accommodate the blunt anterior end 65 of needle 62, sealing means 26, typically a septum, are formed such that blunt anterior end 65 of needle 62 can easily penetrate sealing means 26. Preferably, this can be 15 accomplished by using a slitted sealing means 26.

In a second alternative embodiment, also depicted in Figure 5, needle 62 does not extend anteriorly of support • member 60. Rather, anterior member 65 is an independent tube, made of metal or plastic which is connected to, or 20 formed integrally with, support member 60 and which is hydraulically connected to needle 62. For convenience of terminology, in all embodiments, needle 62 shall be taken to include both the portion posterior of support member 60 and the portion anterior of support member 60, even in 25 those embodiments wherein the anterior and posterior portions are made of different materials and may not be mechanically connected to each other.

In assembling a blood sampling device 16 to be used in conjunction with protective device 50 having a ־ blunt anterior end, the manufacturer preferably cuts tube 12 at an appropriate location and proceeds to glue, or otherwise attach, each of the cut ends of tube 12 to each of fluid ports 24. Such a technique makes it possible to penetrate only sealing means 26 and not the wall of tube 12 to reach the blood stream.

Needle 62 is mounted in such a way that it projects toward the posterior portion of housing 52 which is shaped so as to accommodate the insertion of a blood sampling container 100. Blood sample container 100 is preferably of the Vacutainer type, i.e., it is in the form of a test tube 102 having a rubber stopper 104 over the open end of test tube 102. The central portion of rubber stopper 104 is penetrated by the posterior end of needle 62 when sampling container 100 is pushed into the posterior end of housing 52.

To prevent the leakage of blood from the posterior end of needle 62 during the period of time between the mounting of protective device 50 onto tube 12 and the insertion of sampling tube 100 into the posterior end of protective device 50, as well as during the period of time between the insertion of successive sampling tubes 100 into the posterior end of protective device 50, the posterior end of needle 62 is preferably provided with a sheath 64, which is preferably made of latex, which sheath 64 fits completely over the posterior end of needle 62 and prevents the leakage of blood.

Sheath 64 is made of materials, and is of a thickness and design, such that when sampling container 100 is inserted into the posterior end of protective device 50, sheath 64 is pierced by needle 62 and does not impede the 5 flow of blood into sampling container 100. When sampling container 100 is removed from protective device 50 sheath 64 returns to its original position and effectively prevents the flow of blood by sealing the posterior end of needle 62.

While the invention has been described with respect to one preferred embodiment, it will be appreciated that many variations, modifications and other applications of the invention may be made.