Automatically operable safety shield system for syringes

Description of the invention

The present invention relates to an automatic safety shield assembly for use with a syringe as well as an automatic safety shield assembly containing a syringe to prevent needle stick injury.

Needle-stick injuries are a significant health risk as they often spread disease from one person to another. When a needle is injured, long-term observation of the injured person is necessary because of, for example, HIV or hepatitis (jaundice), and it may also be necessary to limit the work of these people or the contact with the people they work with. From experience, even if the injured person has not been infected, this is a serious injury and very costly for medical personnel. First of all, there would be no infection if an injury was foreseen. Needle-stick injuries are of particular concern to medical personnel who are most exposed to the possibility of infection and who have the most frequent contact with sick patients. In general, it is desirable to understand the risks of needle stick injuries to prevent them from occurring, and various types of safety systems are available that either retract the needle or shield it after use to reduce the possibility of needle stick injury. The use of such security systems is advocated and enforced by various US legislation as well as by life insurers and medical personnel.

Exemplary prior art containment systems are included in EP 0966983. Reference EP 0966983 discloses a shield assembly for pre-filled syringes including an outer syringe holder and an inner shell. In use, the pre-filled syringe has a barrel having a collar, a spaced needle and a plunger which is housed within a housing defined by an outer casing and an inner housing, and is retained by the outer casing. When sufficient pressure is applied to the holder by the syringe barrel (e.g., by the pressure exerted on the plunger when the contents of the syringe barrel have been fully injected), the shield is released and is pushed in the longitudinal direction by a spring interposed between the barrel and the shield, placing the shield in place. extended position and covering the needle.

However, the prior art units contained in EP 0966983 cited above have many drawbacks and potential problems in their design and construction. For example, the assemblies of EP 0966983 are prone to inadvertently release the shield mechanism when a sufficient force (namely due to accidental discharge) on the syringe barrel will in turn exert sufficient force on the outer holder, thereby releasing the shield mechanism. Also, the syringe may be inserted into the outer holder / inner housing structure with sufficient force to cause the syringe to be retained by the casing which may cause the shield mechanism to be released. Alternatively, this possibility may be avoided by placing the syringe in the housing defined by the holder before engaging the shield with the holder. However, this method of fabricating the assembly is somewhat complicated and inconvenient, and could make it impossible to sell and distribute the holder / shield design separately from any syringe that uses such a design. Moreover, releasing the shield mechanism requires a separate step of exerting more force on the plunger rod than the force applied during injection, and then being ready to remove the needle from the patient. The needle may stick during this operation. Another disadvantage disclosed is that the spring stretches to cover the syringe barrel. This can be particularly troublesome when injecting a patient because the contents of the syringe barrel are not fully visible when the spring is stretched, when it may be necessary to see the contents to ensure that the patient has been dosed with the correct dose. Likewise, the extended spring makes it difficult to see the label on the syringe barrel, which may be necessary to confirm that the patient has been administered the correct medication.

The shield mechanism including the shield, spring, ratchet and holder must be connected to each other (see for example Fig. 5 in EP 0966983), i.e. the safety shield assembly can be undesirably long.

Often, when using syringes, it is necessary to place the needle at a well-defined acute angle (for example, it may be when a solid medicine must be placed shallowly under the skin), where the vein tissue is punctured by the needle, causing bruising of the tissue and injury. which may affect the effectiveness of the injected medicine. Large safety guards must not have a finger clip (collar) around their complete circumference while still

It is possible to achieve a sufficiently sharp (namely flat) angle between the needle and the skin of the patient, and therefore have laterally protruding flanges arranged radially opposite to each other. They are typically used so that when the needle enters the skin, the collars are positioned so that they are not in contact with the skin (that is, they are parallel to the plane of the skin's surface). However, depressing the plunger (which may require a correspondingly high force when injecting, for example, solid medicaments in a careful and controlled manner) may subsequently prove difficult as the flanges are misaligned. Users sometimes prevent this and obtain a good collar grip by rotating the syringe 90 degrees after the needle enters the skin (namely so that the collars are perpendicular to the plane of the skin surface). However, the high lumen and sharp edges of the needle tip can cause rotation that cuts through the patient's "vein" tissue. Naturally, this is a problem and it would be desirable to avoid it.

US Patent 5,163,918 discloses an accessible safety syringe having a protective cover. However, its construction differs significantly from that presented in the present invention and has many significant drawbacks which are overcome by the present invention. In particular, these drawbacks arise from the syringe barrel forming part of the safety guard mechanism, the use and placement of the extending spring, the restriction of the movement that can be achieved by the syringe plunger, and the safety clips provided in the syringe.

The spring is also exposed when the securing sleeve is not in the retracted position. While moving to the extended position, this movement can be easily restrained by grasping the spring by, for example, a user's hand or by catching a garment, etc. The spring in various embodiments of the present invention is always encapsulated and thus will not interfere with anything.

The securing sleeve of US Patent 5,163,918 also has finger grips that are gripped by the user. When using them, the safety sleeve cannot extend over the needle until the user releases these grips on the sleeve or plunger. By doing this with the needle in the patient, you can control sudden movement of the needle and tissue damage. Thus, the needle can only be covered protectively after it has been withdrawn from the patient, and this operation is not completed until the user consciously insert the safety sleeve or plunger, as a result of which the needle may unnecessarily expose it. The present invention provides an automatically operating shield assembly (namely, that acts by fully depressing the plunger rod and without any additional intervention by the user) that covers the needle as it is retracted from the patient, ensuring that the needle is not exposed. The automatic actuating assembly of the present invention enables, with a single fluid movement (pressing the plunger rod) both the administration of the drug to the patient and the actuation of the safety guard assembly.

Specifically, the spring used to pull the safety barrel over the needle is provided on the syringe barrel. As described above, this is a disadvantage as it can damage the barrel and can interfere with the maturation of the contents of the syringe barrel, and thus it may be difficult or impossible to provide well-defined doses of medicaments. When administering solid depots to patients, medical requirements typically require that the presence (or absence) of the depot in the syringe barrel can be readily seen by the eye, both before and after injection. The spring closing the syringe barrel will actually be in the way.

In order to prevent undesirable release of the release mechanism, the plunger of US 5,163,918 is designed with a removable safety means including either a tearable band or a removable cap through which the plunger is free to move but not release the ratchet mechanism. This can occur when administering an injection to a patient where it is important to the healthcare professional that the locking devices have not been removed, when the plunger has to be retracted to allow removal of the locking devices. This can cause discomfort and trauma to the patient. Embodiments of the present invention provide alternative safety means that must be removed before the piston is moved, thus avoiding the above problem.

Moreover, the locking mechanism of the present invention comprises (see below) an outer shell stopper which locks it in place in its retracted position preventing it from both being pulled out later and pulled back. And US patent 5,163,918 requires additional flaps to achieve a similar purpose, which of course unnecessarily complicate the device. While not required by the present invention, it is provided in certain example embodiments

There are also additional joining means to prevent later undesirable pulling out of the outer casing, thus making the present invention more mechanically strong.

Furthermore, the design of the syringes according to US 5,163,918 inevitably makes them longer (long) than those of the present invention. When the safety sleeve of cited US 5,163,918 inevitably moves to its extended position, a significant portion of the syringe barrel remains covered. That is, in order to cover a large needle a long retaining sleeve is needed and thus a long syringe barrel is needed. This makes the entire syringe unnecessarily long and bulky, and its size can cause patient anxiety. In contrast, the outer casing of the present invention, in its extended position, leaves a relatively minor portion of the syringe barrel covered. This means that the device according to the present invention can be smaller and more handy.

The syringes manufactured, according to cited US 5,163,918, must be manufactured and sold as a kit.

Other security cover assemblies are included in US 5,201,720, US 5,271,744, US 5,855,839, US 4,850,968 and cited EP 0966983.

An automatic safety shield assembly for use with a syringe, including an inner holder having a proximal and distal portion and providing a housing inside which receives a syringe, an outer housing having a proximal and distal portion mounted externally from the inner holder and movable axially with respect to the syringe. internal mount between retracted and extended positions, a spring positioned between the first tab on the inner holder and a second tab on the outer shell and pulling the outer shell to its extended position, the inner holder having at least one first hole, and the outer shell having at least one first stop engaging the first hole when the outer casing is in the retracted position and the inner holder has at least one first cutout further to the first opening, and the first stop is connected to the first cutout, when the outer shell is in the extended position, the invention is characterized in that the pawl is located inside the inner holder and is axially movable with respect to the inner holder to make contact with the inner holder. with the first stop, when engaged with the first opening, an axial movement of the pawl disengages the first stop from the first opening and a spring moves the outer shell into the extended position.

Preferably, the first detent and the second detent are disposed on distal portions of the inner holder and outer shell, respectively.

The assembly further comprises a syringe consisting of a barrel, needle, plunger and plunger rod movable within the barrel, the plunger rod having a projection, and the syringe structurally connected to the pawl such that movement of the plunger rod projection into contact with the pawl causes the first stop to disengage from the first. hole, allowing the spring to move the outer cover to the extended position.

The syringe has a safety handle removably attached to the portion of the plunger rod extending from the barrel, and the plunger rod moves when the safety handle is attached to the plunger rod.

The outer shell and inner holder have proximal abutments and distal abutting surfaces, respectively, opposed to each other that engage each other to prevent movement of the outer shell beyond its extended position.

The inner holder and outer shell are generally cylindrical in shape and have a cross-section selected from the group consisting of circular and elliptical shapes.

The inner holder and outer shell may be of any desired shape. For example, they may be generally cylindrical in shape. An example of a cylinder would be a cylinder with a circular cross section (usually a correct circular cylinder). Alternatively, the cylinder may have an oval cross section. This can be particularly useful in securing, that is, the inner holder and outer shell cannot be misplaced with each other, or rotate with each other during use. The cylindrical shapes may be slightly conical, for example with a taper of at least 0.5 degrees.

At least the inner holder and outer shell have guide means for axial movement to prevent relative rotation of the inner holder and outer shell.

The inner holder has a groove, corresponding to the first stop, along which the first stop is movable.

PL 199 979 B1

Preferably, the outer cover has a groove, corresponding to each of the distal abutment surfaces, along which the distal abutment surface is sliding.

The inner holder includes an inner holder latch having a radially inwardly projecting distal flange having an upper abutment surface which, when contacted by the syringe, prevents further movement of the syringe within the inner holder.

Preferably, the inner holder includes syringe engaging means for attaching and holding the syringe.

The inner holder has at its proximal end at least one radially projecting projection serving as a finger grip.

Preferably, at least one radially projecting projection at the proximal end of the inner holder is a flange extending around the entire circumference of the inner holder.

The inner holder further comprises piston rod retainers which prevent the piston rod from retracting when it is at least close to its most forward position.

An automatic safety guard assembly comprising a syringe having a barrel, needle, plunger and plunger rod movable inside the cylinder, the plunger rod having a projection and the inner holder having a proximal part and a distal part constituting a full housing inside which the syringe is placed. and the outer casing has a proximal part and a distal part, and is mounted outwardly from the inner holder and moves axially with respect to the inner holder between a retracted and extended position, and the spring is positioned between the first distal tab on the inner holder and a second distal tab on the outer shell, and pulling the outer shell to its position extended and the inner holder has at least one first opening and the outer shell has at least one first stop, which is connected to the first opening when the outer shell is in the retracted position and the inner holder has at least one first recess further to the first opening and the first stop connects to the first opening when the outer shell is in the extended position according to the invention, characterized in that the syringe is structurally attached to an inner holder and an outer shell, so that that movement along the axis of the piston rod projection with respect to the inner holder causes the piston rod projection to contact the first stop when engaged with the first opening and disengages the first stop from the first opening whereby the spring moves the outer skirt into the extended position.

Preferably, the syringe has a safety catch removably attached to a portion of the plunger rod extending from the barrel, and the plunger rod moves when the safety catch is attached to the plunger shaft.

The present invention enables the manufacture of the syringe, optionally containing the drug, separately from the manufacture of the safety guard assembly, where the two parts are then joined together. This means that a stock of safety covers can be prepared without the need to incur costs for the manufacture of the complete device. Likewise, a wide variety of pre-filled syringes can be stocked and combined with safety housings when necessary. All of this can serve to reduce the stockpile (thus saving the manufacturer's money) and is beneficial to the manufacturing process to immediately respond to the demands of any particular product.

The present invention also has the advantage over the cited solution according to US 5,163,918, that when a syringe is filled by medical personnel and then used by them, the prior art device allows only a partial movement of the plunger, i.e. when filling the syringe, it is not avoided being closed in it. air that must then be purged. Removing the air can be very difficult, if not impossible, and the air injected into a patient usually causes tissue damage. The present invention allows the plunger to be fully moved in the syringe barrel and thus air may be purged prior to expulsion of the drug in the syringe. The filled syringe can then be connected to the safety guard assembly and the medication can be administered to the patient.

The invention overcomes the disadvantages of the prior art and provides an alternative and improved tamper evident syringe assembly. The particular advantages of the present invention are that it is less bulky than prior art devices, that the safety shield mechanism is less likely to be accidentally released and withstands force tests beyond the casing and shroud, for example by applying force to the syringe barrel that the mechanism the safety skirt is actuated by the movement of the plunger rod instead of the pressure exerted on the syringe barrel, and that it can

It should be performed as an integral part in the injection process instead of in an additional separate step, and that in various embodiments its spring does not extend substantially over the syringe barrel.

The inner holder and / or outer casing may be formed as a single piece or may be composed of more than one piece. Such a structure will be apparent to those skilled in the art.

All the embodiments of the present invention have various advantages over the prior art regarding movement of the plunger rod, not for example a syringe barrel, which allows the spring to move the skirt into the extended position. This is the typical position where the plunger rod is fully depressed and the contents of the syringe expelled and, for example, injected into the patient. Detachment of the first stop from the first opening can be accomplished either by direct contact of the piston rod projection with the first stop or by indirect contact of the piston rod projection with the first stop.

Direct contact can be achieved by, for example, designing the piston rod with a stopper that has an axial extension which, when the rod is pressed down, contacts the first stop. Alternatively, the piston rod may, for example, be designed with a butterfly stop and additionally with a protrusion which contacts the first stop when the piston rod is depressed.

Indirect contact may be achieved by any arrangement that can contact the movable body of the eye (or protrusion of the body of the eye) to the first stop. The actual nature of the system will depend on the design of the piston rod. For example, the plunger rod may have a butterfly stop which, when the plunger rod is depressed, contacts a member (such as a pawl) within the inner holder which in turn contacts the first stop and causes it to disengage from the first opening.

The first stop may be snap-fit ​​to the first cutout. It can engage the first cutout such that movement is prevented along the axis of the distal and proximal outer shell with respect to the inner holder. The first cutout of the inner holder may be replaced by any other structure or feature, for example a projection such as a cone-shaped projection that restrains relative movement of the inner holder and the outer shell, although it is preferred to prevent any movement along the length. axis.

The first distal detent may protrude outwardly from the inner holder and the second distal detent may protrude inwardly from the outer shell.

The syringe may be held within the inner holder by any suitable means. For example, to ensure proper placement of the syringe with respect to the inner holder, the syringe may abut the inner holder hook, for example the top surface of the first distal flange of the inner holder. It may also be advantageous to design an inner holder with syringe coupling means to attach and hold the syringe. For example, the inner holder and barrel of a syringe may be designed to form an interference fit where a syringe once inserted into the inner holder is only movable when a significant force is applied, for example at least 50N, and particularly at least 70-80N or 100N. Thus, the syringe may be stationary along its axis with respect to the inner holder.

The use of an interference fit (also applies to a friction fit) obviates the need for other retaining mechanisms for the syringe, for example, frustoconical portions formed in the inner holder to hold the syringe in a predetermined area. This means that the syringe does not need any flanges, which are typically designed in the shape of finger grips, which makes the syringe smaller than similar devices used in the prior art and thus the safety guard assembly is smaller. Of course, it may be desirable to maintain at least a small flange to simply assist in manipulating the syringe barrel during syringe manufacture, especially for pre-filled syringes.

Suitable materials for the construction of the inner holder and outer cover of the device can be a wide variety. Preferably, the material is transparent enough to allow the contents or the label of the syringe to be seen within the inner holder to be seen. Suitable materials are: polystyrene, modified polystyrenes and polystyrene copolymers, polycarbonates, polyethersulfones, polypropylenes, copolymer resins of cyclic olefins, copolyesters such as copolyester

PL 199 979 B1

DN003 Eastar® [copolyester made from terephthalic acid (or dimethyl terephthalate), polyethylene glycol and 1,4-cyclohexanedimethanol], acrylonitrile butadiene styrene copolymer (ABS). A particularly preferred material is DN003 Eastar® copolyester (Eastman Chemical Company). MABS (methyl methacrylate / acrylonitrile / butadiene / styrene copolymer / Terlux 2812TR®) are also useful. Polycarbonate including Lexan® GR 1210 and Lexan 124R-112. Resin copolymers of cyclic olefins including Topas® 6013 X5.

In some applications, the devices of the present invention may need to be delivered under sterile conditions. Those skilled in the art will be familiar with the sterilization of pharmaceutical devices, and methods for sterilizing such devices, for example, using heat, gas techniques, or gamma radiation. Due to the physical properties of the materials used in the construction of the devices of the present invention, it is required that sterilization does not significantly affect them. For example, in some materials, the sterilization process can cause stress cracks or change the material from transparent to opaque. The preferred method of sterilizing the devices of the present invention is gamma irradiation. However, gamma radiation can induce changes in the color of plastic materials and can also cause stress cracks in the plastic materials. It was found that gamma radiation on DN003 Eastar® copolyester did not cause significant color variation and did not significantly affect the physical properties of the material. Thus, a preferred material for the devices of the present invention suitable for use in gamma sterilization is Eastar® DN003 copolyester.

The syringe barrel can be made of polypropylene. Alternatively, the syringe barrel may be divided into multiple parts. For example, it may have an upper and a lower part made of highly dense polyethylene joining and holding a transparent part such as glass or polystyrene. The lower part can engage the inner casing. The transparent portion may be lenticular to provide an enlarged view of the contents of the syringe barrel.

In the case of syringe barrels having no flanges or having reduced flanges, the inner holder may be made such that the inserted syringe barrel acts to reduce the possibility of the first stop and the first opening inadvertently disconnecting, e.g. it may have a collar with a projection, for example an axial annular projection which, when the plunger rod is depressed, it extends around the outside of the syringe barrel and contacts, directly or indirectly, the first stop causing its disengagement.

The reduced dimensions of the inner holder and outer shell (with respect to the shell design and the prior art holder) allow the provision of at least one radially projecting projection used as a finger grip, e.g. a collar with useful dimensions, projecting for example at least 2mm, 3 mm, 4 mm or 5 mm around the entire circumference of the proximal end of the inner holder. This allows even large-diameter needles to be placed in the patient at an angle that does not puncture the vein. This is particularly useful as it allows the user to easily hold the inner holder in various positions and allows the hand to be repositioned without losing the grip required for proper injection, or without the necessary syringe rotation and a possible piercing of the vein.

The outer cover (instead of the inner holder) may be loose, namely it may not have radially projecting projections at its proximal end such as flaps or a collar used as a finger grip.

The syringes of the present invention can be used with subcutaneous injection of liquids, suspensions such as microparticulate solutions or solid drugs (also for depots). Such depot injections require the syringe plunger to extend through the syringe needle opening to ensure that the solid drug is completely expelled from the syringe. The protruding plunger may act to reduce the risk of needle stick injury if the needle is exposed for any reason, thus keeping the plunger in the extended position, for example to ensure that the depressed plunger rod cannot be pulled back, which can provide useful relief. additional protective properties. Examples of microparticle compositions that can be used in the invention may include the Lupron® leuproid microparticle composition. Examples of solid medicaments that can be used in the present invention may include a Zoladex® goserelin depot composition.

PL 199 979 B1

The interior of the body may further include piston rod retainers which prevent the piston rod from retracting when it is at least in its most forward position. In the farthest position, the piston rod causes the first stop to separate from the first notch, and the furthest position is typical when it is desired to retain the piston rod, although it may also be desirable to keep the piston rod in a proximal forward position. For example, the piston rod retaining means may include a deflecting member or members, for example a frustoconical or raised, or so-called bouncing-tooth structure, in the inner holder which allows the piston rod to be pressed through the upper (namely proximal) inclined surface ( usually by elastic deformation thereof), but which enable the lower (namely distal) abutment surface to prevent removal of the piston rod.

The invention has many advantages. First, in various embodiments of the invention, particularly those that use, for example, a ratchet to contact the moving piston rod with the first stop, the piston rod retainer may make it less susceptible to accidental (or deliberate) forces separating the first stop. a stop from the first cut, through, for example, sticky fingers, in the gap formed between the piston rod and the inner body, moving the pawl, simply by reducing the size of the gap. Second, after the device of the invention is used and the outer cover is in the extended position, if the device has any mechanical damage, the outer cover may move back towards its retracted position and the first stop will not be able to re-engage with the device. the first notch, so the outer cover will always be pulled by the retracting spring towards its extended position.

This arrangement of the spring with the first and second distal hooks of the inner holder and outer shells, that is, when the extended spring covers the area from the first distal catch of the inner holder to the second distal catch of the outer shell, for example the spring will not stretch to cover the syringe barrel. Thus, when the inner holder is made of a transparent material, it is possible to see the contents of the inner holder even after the outer shell has been pulled out, which means that in the case of drug solutions, complete discharge of the contents of the syringe can easily be confirmed at any time.

The fact that the spring does not extend to cover the syringe barrel is also a useful advantage as the spring cannot damage the syringe barrel, and such failure is a known problem in the art that often requires the use of an additional safety feature when, for example, a glass syringe is used. cylinder (e.g., reference EP 0966983, column 7, lines 19-21).

In order to ensure that compression of the shield assembly by the user does not prevent it from operating, the inner holder may be designed with a finger gripping area including a collar and a rigid section of the inner holder. Squeezing it will not reduce the internal dimensions of the inner holder, so the safety shield assembly will function properly.

The first stop may engage the abutting surface of the first opening. The first stop may be designed in the shape of an arcuate flexible member extending from the outer shell, that is, extending outwards and then inwards. Such a structure may allow the first stop, when engaged with the abutting surface of the first opening, to center inwardly on the axis of rotation at the connection point. That is, if an attempt is made, either accidentally or deliberately, to disengage the first stop and the first opening by pulling them separately, they will actually connect even more tightly than before and will thus be more resistant to being pulled separately. This is a feature which is absent from other prior art devices which, for example, have flexible stops that disengage when a sufficient force is applied.

The invention is illustrated in an embodiment in the drawing which shows one embodiment of the protective shield and the syringe structure, and Fig. 1 is a side view of the protective shield and the syringe structure of the invention having the entire outer shield in position. Fig. 2 shows a sectional view along the line MM of Fig. 1, Fig. 3 shows a side view of the structure of Fig. 1 rotated axially through 90 degrees, Fig. 4 3 is a sectional view along line NN of fig. 3, fig. 5 is a side view of the inner holder, fig. 6 is a sectional view along line CC of fig. 5, fig. shows a cross-section

Along line EE in figure 5, figure 9 is a sectional view along line AA in figure 5, figure 10 is a side view of the inner holder of figure 5 rotated axially by 90 degrees, figure 11 is a sectional view. along line BB of Fig. 10, Fig. 12 is a side view of the outer shell, Fig. 13 is a sectional view taken along line KK in Fig. 12, Fig. 14 is a section taken along line HH in Fig. 12, Fig. 15 is shown in Fig. a side view of the outer shell of Fig. 5 rotated axially 90 degrees, Fig. 15a is an enlarged view of the area marked by the circle L in Fig. 15, Fig. 16 is a section along line GG in Fig. 15, Fig. 17 is a side view of the pawl, Fig. 18 Fig. 17 is a sectional view along line FF of Fig. 17, Fig. 19 is a top view of the pawl of Fig. 17, Fig. 20 is a perspective view of the safety shield and syringe structure shown in more detail in Figs. 21, 30 and 31 fig. 21 is a partially cut-away perspective view of the safety shield and syringe structure of the present invention with the outer shield in the extended position, Figure 22 is a front view of the structure of Figure 1 in the extended position, Figure 23 is a sectional view along line BB with Fig. 22, Fig. 24 is a side view of the structure of Fig. 1 in the extended position, Fig. 25 is a section view along line CC of Fig. 24, Fig. 26 is a front view of the second example of the safety shield and the syringe structure to prevent the safety shield from slipping off, fig. 27 is a sectional view along line CC of fig. 26, fig. 28 is a side view of the structure of fig. 26, fig. 29 is a sectional view. along line BB of Fig. 28, Fig. 30 is a section through an alternative embodiment of the present invention generally corresponding to that shown in Fig. 25, and Fig. 31 shows an alternative section through the structure of Fig. 30 generally corresponding to that shown in Fig. 4.

In the first embodiment, the safety shield and syringe structure 10 of the present invention consist of an inner holder 20, an outer shell 30, a metal spiral spring 40, a ratchet 50, and a syringe 60.

The inner holder 20 is constructed of Eastar® (Eastman Chemical Company) copolyester DN003 and has an elongated generally cylindrical shape defining the housing 70, and has a proximal inner holder portion 80 and a distal inner holder portion 90 and ends 100, 110 defining openings at the ends. The proximal portion 80 widens towards the tip 100 to form an outlet 111 that is gripped by the user's hand in use. The outlet 111 is substantially rigid so that the pressure exerted by the user does not reduce its diameter and inhibits the operation of the safety guard assembly 10 and thus prevents the outer cover 30 from slipping out. The outlet 111 has a radially outwardly projecting flange 120 that acts as a finger grip in use. allowing the structure 10 to be easily manipulated by the user. At the distal end of the mouth 111, two first openings 130 are radially relative to each other, and have further surfaces defined by first two frustoconical portions 140 defining upper abutment surfaces 150 and lower inclined surfaces 160. Separated from the frustoconical portions 140, they extend the first grooves 145 are axially oriented. Further downstream 90, axially spaced from the first holes 130, are two first slots 170 with two flexing tabs 180 extending axially therein. The distal ends 181 of the tabs 180 extend radially outward from the proximal ends 182.

From the first openings 130, the first frustoconical portions 140 and the first notches 170, extend axially rotated 90 degrees second grooves 185. Further downstream 90 are two catches including two outwardly frustoconical portions 90 having an outwardly extending frusto-cone portion 90. upper abutment surfaces 200 and lower sloping surfaces 210. In the inwardly radially truncated second portions 190 there is a radially inwardly extending ring 220 which (see below) engages the syringe 60. Axially spaced from the ring 220 is a radially inwardly projecting distal flange 230 having an upper and lower abutment surface 231, 232.

The outer shell 30, also made of DN003 Eastar copolyester, has a shape that corresponds to that of the inner holder 20, that is, it moves axially on the inner holder 20. The outer shell 30 has a proximal and distal portions 240, 250 and a proximal and distal tip. 260, 270. The proximal end 260 has two radially inwardly projecting opposing flanges having abutment surfaces 280 with axially extending inclined side walls 290. The abutment surfaces 280 and the side walls 290 are shaped such that they can cover the second frustoconical portions 190 with an interference fit. The proximal end 260 also has two stops 300 pivoted axially 90 degrees from the stop surface 280. The stops 300 have bending arms 310 of a generally bilaterally symmetrical shape10.

They are trapezoidal and have heads 320. The distal end of the arms 310 extends inward and moves axially, and the arms 310 extend outward. Heads 320 extend into the proximal end of arms 310 and have abutment surfaces 330. Distal end 270 includes a generally annular shoulder 340 having an inclined abutment surface 350 axially spaced from the second distal detent 370 having distal abutment surface 360.

A substantially cylindrical pawl 50 has a proximal and distal end 380, 390 and is designed to fit into the mouth 111 of the inner holder 20 so that it moves axially in the inlet 111. The distal end 390 has an inwardly curved neck 400.

Syringe 60 has a substantially cylindrical barrel 410 containing a solid drug (not shown), a collar 420 at its proximal end, and a needle 430 and a removable needle shield 431 at its distal end. The piston 440 slides within the cylinder 410. The piston rod 450 is connected at one end to a piston 440 and the other end has a flange provided with a thumb button 460. The safety catch 470 is removably attached to the portion of the piston rod 450 extending from the cylinder 410, and prevents movement of the piston rod 450.

The containment shell and syringe structure are designed such that a metal spiral spring 40 is initially positioned inside the outer shell 30 so that it contacts the abutment surface 360 ​​of the distal catch 370. The end 110 of the inner holder 20 is then gripped and slid into it. proximal end 260 of the outer shell, and slid toward distal end 270. The arms 310 and heads 320 of the stops 300 are angled outward as they pass through the sloping surfaces 160 of the frustoconical portion 140 before they are inserted into the frustoconical portion 140, at which point they snap inward so that the abutment surfaces 150 , 330 are located opposite each other. Further, the insertion of the inner holder 20 prevents the end 110 from contacting the sloped abutment surface 350 of the outer shell 30. The sliding of the inner holder 20 into the outer shell 30 causes the spring 40 to be compressed between the abutment surface 360 ​​of the outer shell 30 and the lower abutment surface 232 of the inner holder 20. Releasing the handle on inner holder 20 allows spring 40 to stretch slightly while pulling inner holder 20 and outer shell 30 separately, and opposing abutment surfaces 150, 330 engage each other and prevent later relative movement of inner holder 20 and outer shell 30. Outer shell 30. now in the retracted position.

The structure of the arms 310 and heads 320 of the stops 300 is such that the center of the pivot axis of the arms 310 is directed radially inward of the contact area of ​​the abutment surface 150, 330. Contrary to prior art devices, where the holder and cover can be separated by applying sufficient force to them, i.e. by trying to pull separately (namely to disconnect) the inner casing 20 and outer casing 30, this causes the stops 300 to be pulled more strongly. merge with inner cast 20.

The catch 50 is then slid into the mouth 111 of the inner holder 20 such that the neck 400 contacts the heads 320.

Next, the syringe 60, but first the needle 430, is inserted into the mouth 111 of the inner holder 20 and is advanced towards the tip 110 such that the needle 430 and the needle protector 431 protrude from the tip 110. The insertion operation is stopped when the barrel 410 contacts it. the upper abutment surface 231 of the distal flange 230. The proximal and distal ends of the barrel 410 of the syringe 60 are made of high-density polyethylene, and are interference-fit to the ring 220 such that it cannot be easily removed from the inner holder 20 without the use of sufficient force. The collar 420 prevents removal of the pawl 50 from the mouth 111, but exerts no force on the pawl 50 and does not cause the pawl 50 to move, as a result of which the inner holder 20 and the outer cover 30 can become detached.

In use, the safety catch 470 is removed from the plunger rod 450, and the needle shield 431 is also removed. A needle 430 is inserted into the patient (not shown) and a thumb button 460 is pressed to insert the plunger 440 into the cylinder 410 and expel the drug as fixed (not shown) by the needle 430, which causes the plunger 440 to extend from the needle. Simultaneously (namely, not part of a separate step), the thumb push button 460 enters the outlet 111 and contacts the pawl 50, causing it to move axially. Axial movement of pawl 50 is restrained by the heads 320, but a curved neck 400 flexes the heads 320 outwardly so that the pawl 50 moves axially.

PL 199 979 B1

Sufficient axial movement of pawl 50, and thus outward movement of heads 320, causes opposing abutment surfaces 150, 330 to disengage to allow axial movement of outer shell 30. Spring 40 separately pulls inner holder 20 and outer shell 30 and when needle 430 is retracted. from the patient 480, the outer cover 30 slides over the inner holder 20 to cover the needle 430 and prevent any needle stick injuries. During the advancement step, rotation of the inner holder 20 and outer cover 30 relative to each other is prevented by the grooves 145, 185 guiding the stop heads 320 300 and the second frustoconical portions 190, respectively. 320 pass over the angled tabs 180 and snap into the first cutouts 170, then preventing movement along the axis of the inner holder 20 and outer shell 30. At the same time, the abutment surfaces 280 and side walls 290 slide over the frustoconical second portions 190 and snap-fit ​​where the abutment surfaces 280 contact the upper abutment surfaces 200, and prevent any subsequent dislocation as an added security feature. The outer cover is now locked in the extended position. All handling of the protective shield and syringe structure 10 of the present invention can be easily performed by a person with one hand.

The second embodiment is the same as the above except that the syringe barrel 410 does not have a collar 420 and the pawl 50 is not retained in the outlet 111, instead it is replaced with a thumb button extension 600 of the thumb 460. This design reduces the possibility of the opposing abutment surfaces 150, 330 inadvertently disengaging when inserting the syringe 60 into the inner holder 20, or, on the other hand, reducing the possibility of the opposing abutments 150, 330 accidentally disengaging. Due to the absence of the collar 420, it is possible to reduce the diameter of the mouth 111, thus reducing the overall dimensions of the inner holder 20, or enlarging the collar 120 to allow better gripping by the user.

The third embodiment is the same as the first except that the outlet 111 has frusto-conical deflecting portions having upper (proximal) inclined surfaces and lower (distal) abutment surfaces substantially perpendicular to the inner axis of the holder. In use, as the thumb button 460 enters the outlet 111 (and the solid drug is expelled from the needle 430 and the piston 440 exits the needle 430, it deflects the cone-shaped parts and extends beyond them. at which point they return to their original shape and the present abutment surfaces oppose the thumb button 460, preventing it from being removed from the mouth 111. That is, the plunger 440 is locked in a position extending from the needle 430 such that even if the outer cover 30 is removed or damaged such that the needle 430 is exposed, needle stick is substantially prevented.

An alternate embodiment has altered (substantially narrower than those shown in the other drawing figures) dimensions as shown in Figs. 30, 31, 20 and 21. In particular, the inner holder 20 is about 68 mm long and about 10 mm in diameter at the proximal portion. which is covered by an outer shell 30 and has a narrower collar 120. As can be seen, the outer shell 30 is constructed in two parts.

The pawl 50 also has first and second curved protrusions 600, 610 extending radially outward about their entire periphery, and the pawl 50 (and / or inlet 111) is sufficiently elastically deformable to allow them to be pushed through a corresponding third curved protrusion 620 which protrudes. radially inward around the entire circumference of outlet 111. When the device of the present invention is collapsed, the catch 50 is placed in the mouth 111 of the inner holder 20 and the first curved protrusion 600 abuts the third curved protrusion 620.

Sufficient downward force can be easily applied to the pawl 50, causing it to elastically deform to allow the first curved shoulder 600 to pass over the third curved shoulder 620. As the pawl 50 is then pushed downward, the second curved shoulder 610 abuts the third curved shoulder 620. A sufficient downward force is then applied to the pawl 50 causing it to elastically deform to allow the second curved shoulder 610 to pass over the third curved shoulder 620. The pawl 50 is thus fully seated as shown in Figures 30 and 31. Although it is easy to apply downward force to place the pawl 50 in the outlet 111, once the pawl 50 is in place it is very difficult for a person to apply sufficient upward force on the pawl 50 to remove it from the outlet. 111, so it can be permanently inserted into the outlet 111.

PL 199 979 B1

In the two-step placing of pawl 50, the devices of the present invention are stacked and packaged with inner holder 20, outer shell 30 and spring 40 interconnected, and with a catch 50 located in the mouth 111 of the inner holder 20 such that the third curved protrusion 620 is positioned. between the first and second curved protrusions 600 and 610. A syringe 60 may be positioned in the mouth 111 and coupled to the inner holder 20 without contacting the pawl 50. Even if the pawl 50 accidentally contacts the syringe 60 during its insertion, the second curved protrusion 610 will keep it from moving past the third curved protrusion 620 and thus prevent the stops 300 from disengaging from the first holes 130. Once the syringe 60 has been fully seated, it may then be sufficient force is applied to the pawl 50 to push the second curved protrusion 610 through the third curved protrusion 620. The syringe 10 structure is now ready for use.

Depending on the structure and deformability of the outlet 111 and the thumb button 460, as well as the size of the thumb button 460, it is possible to enlarge the radially inwardly directed protrusion around the overall circumference of the outlet 111 to prevent removal of the button. for thumb 460 from outlet 111.