GB2469671A

GB2469671A - Syringe sheath remover

Info

Publication number: GB2469671A
Application number: GB0906965A
Authority: GB
Inventors: Mark Eaton
Original assignee: Owen Mumford Ltd
Current assignee: Owen Mumford Ltd
Priority date: 2009-04-23
Filing date: 2009-04-23
Publication date: 2010-10-27
Also published as: GB0906965D0

Abstract

Provided is apparatus for removing a sheath from a syringe. The sheath provides a sterile cover for a needle of the syringe. The apparatus comprises a housing defining a first opening and a sheath-gripper. The sheath-gripper is coupled to said housing and defining a second opening in front of said first opening such that a sheath of a syringe can be inserted through said second opening and into said first opening. The sheath gripper is deflectable, by a user, relative to said housing and about an axis substantially transverse to the direction of insertion of the sheath into the openings.

Description

APPARATUS FOR REMOVING A SYRINGE SHEATH

Technical field

The present invention relates to apparatus for removing a sheath from a syringe.

Backciround Various types of injection devices are available for assisting with the injection of a rnedicament into a patient (human or animal), and which are configured to receive a standard, pre-filled glass or plastic syringe tipped with an injection needle. These devices may have a dose setting mechanism and a main drive spring for driving a plunger into the syringe so as to expel the medicament out through the needle. Injection devices may comprise a further spring for driving the needle out of the device housing and into the patient's skin, prior to activation of the main drive spring to expel the medicament.

In order to maintain sterility prior to use, and to avoid "sticking" injuries, the pre-filled syringe is supplied to the injection device assembler with a rubber or plastic cap, known as a "sheath", covering the needle. The sheath has an interior space for containing the needle, and a sealing end that abuts the adjacent end of the syringe barrel to seal that inner space.

Immediately prior to use, a user (e.g. healthcare professional or patient) must remove the sheath to uncover the needle. This is typically achieved using a sheath removal tool that is inserted by a user into the injecting end of the device. The tool comprises a set of sprung fingers that ride over and along the sheath as the tool is pushed into the device. The fingers then snap into the junction between the syringe end and the sheath. The user can then pull out the tool, bringing the sheath with it.

Particularly in the case of expensive medicaments, it is extremely important to minimise the failure rate of assembled injection devices. Considering the sheath removal solution outlined in the previous paragraphs, it may be difficult to achieve exactly the right degree of flexibility in the fingers to ensure that they can ride over the sheath whilst still providing sufficient force to close over the junction at the rear of the sheath.

GB 2438593 (Cilag), US 2206/01 0588 Al (Brunnberg et a!), WO 2007/047200 Al (Eli Lilly) and US 2006/0270986 Al (Hommann et al) all describe devices for housing syringes and removing sheaths therefrom.

Summary

It is an object of the present invention to provide a sheath removal apparatus that is both easy to use and reliable, reducing the failure rate of assembled injection devices.

According to a first aspect of the present invention there is provided apparatus for facilitating the removal of a sheath from a pre-filled syringe, the sheath providing a sterile cover for a needle of the syringe, the apparatus comprising: a housing defining a first opening; and a sheath-gripper coupled to said housing and defining a second opening in front of said first opening such that a sheath of a syringe can be inserted through said second opening and into said first opening, the boot gripper being deflectable, by a user, relative to said housing and about an axis substantially transverse to the direction of insertion of the sheath into the openings.

In some embodiments, the sheath-gripper may be hinged. The hinge may be formed in an arm coupling the sheath gripper to the housing. The hinge may be biased by a spring or a resilient member. In some embodiments, however, the sheath-gripper is resiliently deformable. This allows the sheath-gripper to flex.

The sheath-gripper may also be deflectable by the sheath upon insertion. The sheath-gripper may be fixed to, or co-moulded with, the housing in such a way as to be deflectable in an arcuate manner between first and second positions.

The sheath-gripper may, therefore, be fixed to, or co-moulded with, the housing at one side of the housing.

The sheath-gripper may be provided with a lip depending from an inner face of the second opening. The lip may engage with a formation formed between an end of the sheath and a shoulder of the syringe barrel.

Further gripping means, such as serrations or protrusions on the inner face of the second opening, may be provided to increase the grip of the sheath-gripper upon removal of the sheath.

The sheath remover may be provided with stabilisers or means to adhere or fix a base of the housing to a work surface, i.e. a wall or lab bench or to prevent slippage thereover, such as a rubberised footplate on the underside of the base.

Such means may prevent the sheath remover from falling over or otherwise reduce slippage along a surface.

Brief Descrition of the Drawincis Figure 1 illustrates a syringe with a sheath covering a syringe needle; Figure 2 illustrates a sheath remover for use with the syringe of Figure 1, the dashed line indicating the sheath-gripper in a second position; Figure 3 illustrates, in plan view, a sheath remover for use with the syringe of Figure 2; Figure 4 illustrates, in cross-section, a first sheath removal stage, using the sheath remover and syringe shown in Figures 1 and 2; Figure 5 illustrates, in cross-section, a second sheath removal stage, using the sheath remover and syringe shown in Figures 1 and 2; Figure 6 illustrates, in cross-section, the sheath remover and syringe of Figures 1 and 2, with the sheath removed; and Figure 7 illustrates, in cross-section, an injection device loaded with the syringe of Figure 1, the sheath of the syringe being inserted into the sheath remover of Figure 2.

Detailed Descriition Apparatus will now be described that enables the easy and reliable removal of a sheath or cap covering a needle of a pre-filled syringe. As has already been outlined above, an assembler of injection devices (e.g. auto-injectors and the like) will typically obtain pre-filled syringes from a supplier. The assembler may have little or no influence over the design of the syringes including the sheaths, and may therefore have to ensure that its device design and assembly process is compatible with the syringe design.

Figure 1 shows a conventional syringe 1, comprising a barrel 2 containing the medicament and a piston 3 located within the barrel. The piston 3 may cooperate with a plunger (not shown) which may extend outwardly from the barrel. The syringe 1 further comprises shoulder portion 4, wings 5 and a hypodermic needle 6 coupled to the opposite end of the barrel. An essentially solid rubber or plastics sheath 7 covers the needle 6 and seals around the shoulder 4 of the syringe barrel 2. At the junction between the shoulder 4 of the barrel 2 and an opposing end 8 of the sheath 7, a small axial gap, channel or formation 9 exists.

Figure 2 is a perspective view of a sheath remover 10. The remover comprises a generally cylindrical casing or housing 11, defining a first circular opening 12.

The housing 11 is of a rigid plastics material. The housing 11 further comprises a sheath-gripper 13. The sheath-gripper 13 is connected to the housing 11 by an arm 14 SO as to be deflectable in an arcuate manner between a resting first position 15 and a second position 16. The deflection occurs about an axis running through the sheath gripper 13 that is substantially transverse to the direction of insertion A of the sheath 7. The arrow B in Figure 2 illustrates the deflection path of the sheath-gripper 13.

The sheath-gripper 13 defines a second circular opening 17. As shown in Figure 3, the first and second openings, 12 and 17, are aligned. This allows the sheath to be inserted through both openings and into the housing 11, as discussed further below. Both openings 12 and 17 are arranged such that the sheath fits snugly through them. The sheath remover 10 is provided with a base portion 18 and a neck 19. The base is broader than the neck in order to aid stability and also provide the user with additional purchase on the sheath remover 10 when gripping the sheath remover.

Grip on the sheath 7 is principally provided by a lip 20, which depends from the sheath-gripper 13 as shown in Figure 2, and an internal face 21 of the second opening 17 opposite the lip 20.

The housing 11 defines a space 22 within the housing 11 to at least partially accommodate the sheath 7. The space 22 is sized to accommodate the sheath with a close fit. Indeed, contact between the inside of the housing and the sheath may assist in sheath removal.

The insertion and removal of the sheath will now be described in more detail with reference to Figures 4 to 6. It will be appreciated, of course, that the syringe 1 and sheath 7 can be encompassed within an injection device, as discussed below in relation to Figure 8. However, for the sake of simplicity, the following description will refer only to the syringe 1 and not to any optional injection device.

In Figure 4, the syringe is shown with the sheath 7 partially inserted into the sheath remover 10. The user manually deflects the sheath remover 10 from the resting first position 15 towards the second position 16, in the direction of arrow o shown in Figure 4. The deflection occurs principally at the arm 14 of the sheath gripper 13. This deflection angles the sheath-gripper 13 towards a plane perpendicular to the axis of insertion of the sheath 7, said axis of insertion being represented by arrow D in Figure 4.

Thus, as the sheath-gripper 13 is held down by the user in the second position 16, the sheath 7 can be inserted through both the first and the second openings, 12 and 17, and into a space 22 defined within the housing 11.

With the sheath now accommodated within space 22 of housing 11, the sheath removal procedure can be completed. To remove the sheath 7, the user releases the sheath-gripper 13. The sheath gripper 13 thereby resiles in the direction of arrow E in Figure 5. As a result, the second opening 17 and, in particular, the lip 20 and the internal face 21 of the second opening 17, bite onto the surface of the sheath 7.

Arrow F in Figure 5 shows the sheath remover 10 being urged away from the syringe 1, with the lip 20 and inner face 21 gripping the sheath 7. The sheath 7 is thereby retained within the sheath remover 10, as shown in Figure 6, leaving the needle 6 exposed.

The deflection of the sheath-gripper leads to a change in the effective size of the opening in the sheath-gripper, when viewed from the direction of the insertion of the sheath. As the angle of the sheath-gripper changes upon deflection, the sheath-gripper grips the sheath more or less tightly. For instance, when the sheath-gripper is in a plane perpendicular to the direction of insertion of the sheath into the openings (second position 16), the sheath can move freely into the opening in the sheath-gripper. However, when the sheath-gripper is, for instance, at a 30 degree angle to said direction of insertion (first position 15), then the opening is effectively narrowed, when viewed from said direction of insertion, so that the grip on the sheath is tight.

It will be appreciated that, in some embodiments, the base 18 may be provided with additional stabilising means. This may include a platform which can be clamped or fixed securely to a lab bench or wall.

It will also be appreciated that, during insertion, some deflection of the sheath-gripper 13 can result as the sheath 7 is urged through second opening 17, so that it is not always necessary for the user to hold down the sheath-gripper 13 right until the sheath 7 has been fully inserted into the space 22 of housing 11.

The insertion and removal of the sheath has been described with reference to the syringe 1 only. However, it will be appreciated that sheath removal can also be achieved when the syringe 1 is contained within an injection device 23, as shown in Figure 7, provided that the sheath 7 is suitably exposed and the injection device 23 can accommodate the sheath remover 10 within its casing 24. Once the syringe 1 and sheath 7 have been inserted into the casing 24 of injection device 23, other injection device components (not shown) may be inserted into the casing, behind the syringe, for instance by screwing these components into the casing 24, to thereby lock the syringe 1 into position.

It will be appreciated by the person of skill in the art that various modifications may be made to the above described embodiments without departing from the scope of the invention.

Claims

CLAIMS: 1. Apparatus for facilitating the removal of a sheath from a pre-filled syringe, the sheath providing a sterile cover for a needle of the syringe, the apparatus comprising: a housing defining a first opening; and a sheath-gripper coupled to said housing and defining a second opening in front of said first opening such that a sheath of a syringe can be inserted through said second opening and into said first opening, the sheath gripper being deflectable, by a user, relative to said housing and about an axis substantially transverse to the direction of insertion of the sheath into the openings.
2. Apparatus according to claim 1, wherein the sheath-gripper is hinged.
3. Apparatus according to claim 1, wherein the sheath-gripper is resiliently deformable.
4. Apparatus according to any preceding claim, wherein the sheath-gripper is deflectable by insertion of the sheath.
5. Apparatus according to any preceding claim, wherein the sheath-gripper is deflectable in an arcuate manner.
6. Apparatus according to any preceding claim, wherein the sheath-gripper is provided with a lip depending from an inner face of the second opening.
7. Apparatus according to any preceding claim, wherein the sheath remover is provided with means to adhere or fix a base of the housing to a work surface.