GB2625796A

GB2625796A - Improvements in and relating to medical needle cover arrangements

Info

Publication number: GB2625796A
Application number: GB2219711.5A
Authority: GB
Inventors: Peter Liversidge Barry
Original assignee: TIP TOP COM Ltd
Current assignee: TIP TOP COM Ltd
Priority date: 2022-12-23
Filing date: 2022-12-23
Publication date: 2024-07-03
Also published as: GB2625841A; GB202219711D0; GB202305213D0

Abstract

A medical syringe needle cover arrangement comprises a safety device (8, fig. 1) having a needle shield 19 pivotally mounted on a carrier 18 securable to the syringe or its needle hub. The sterile needle is enclosed within an axially removable needle cover or cap 23 which is soft and forms a seal against the needle hub. When installed on the syringe or needle hub, the hinged shield 19 can be manipulated to move outward from an initial shielding or closed position (figs. 2 & 9) in which the cap 23 is located within the shield 19 and constrained by mutually engaging parts 27, 42 of the cap and shield to prevent distal cap movement away from sealing contact with the hub, into a non-shielding or open position (figs. 3 & 11) in which the cap is removable to expose the needle. The shield may then be movable into a final position (figs. 4 & 13) in which it captures and deflects the used needle.

Description

Improvements in and relating to Medical Needle Cover Arrangements

FIELD OF THE INVENTION

This invention relates to a medical needle cover arrangement for a soft needle cover used in association with a syringe having a medical needle projecting forwardly therefrom. In its preferred aspects, this invention concerns improvements in a soft needle cover associated with a needle safety device arranged to confer needlestick protection to a medical needle projecting forwardly from a single-use syringe.

BACKGROUND TO THE INVENTION

A syringe provided with a medical needle as employed in this invention is intended to be used to penetrate a human or animal body, or for other medical uses such as the penetration of a pierceable membrane of an intravenous medication system. In the following all medical uses of the syringe and needle will be described simply as the penetration of a body, even though specific embodiments may be intended for other medical uses.

A syringe having a needle permanently secured thereto is frequently pre-filled with a liquid drug or medicament and then is used only once to perform an injection. Once used, the syringe and needle must be disposed of in a safe manner. To protect any people who might have to handle such a syringe, either before or after performing an injection, it is becoming a requirement of health and safety legislation as well as best practice to provide the needle with some kind of safety device to minimise the risk of accidental needlestick injury.

Typically, such a safety device may have a shield which is mounted on the syringe and is slidable axially between a needle protecting position and a non-protecting position. -2 -

In the course of manufacture of a single-use syringe having a needle permanently secured to a needle hub at the forward end of the syringe barrel, it is the usual practice to fit a soft needle cover over the needle before the syringe is packaged and then sterilised for storage and transport, prior to filling with a liquid drug or other medicament. Such a cover is usually made of a soft elastomer such as rubber or a TPE and must be compliant with drug compatibility and stability. The rear end of the cover fits onto the needle hub and the sharp tip of the needle penetrates the material of the cover so as to be sealed thereby, but the cover does not bear on the greater part of the length of the needle so as not to remove any lubricant which is usually be applied to the needle. Thus, there is a void around the greater part of the needle, from the hub of the syringe to a location adjacent the sharp tip of the needle. This part of the needle must be maintained in a sterile environment prior to use of the needle. EP 1502617 and EP 1964586 are examples of needle shields that have a rigid outer shield which cover a soft inner (elastomeric or rubber) needle cover, generally as described above.

A significant problem associated with the manufacturing process for a single-use syringe is that in the course of the packaging and sterilisation steps, there is a tendency for a needle cover to be displaced from its as-fitted condition on the hub -a phenomenon known as "pop-off'. This primarily occurs on account of the changes of pressure to which the syringe and cover are subjected in the course of the sterilising process and the fact that the void between the needle and the cover is in effect a sealed space. The problem has been addressed by venting that space, but then there is a possibility that the sterile condition of the needle may be compromised. As a consequence, in an attempt to increase the security of the attachment of a needle cover to the hub of a syringe during the sterilisation process, it is the usual practice to provide at least one formation on the hub of the syringe and a corresponding formation at the rear end of the needle cover to co-operate with the formation on the hub, to mechanically hold the soft needle cover on the syringe hub. For example, an upstanding rib may be formed around the hub, the needle cover having an in-turned flange at its rear end, and which is fitted over the rib to engage there behind and so hold the cover on to the syringe hub in a fixed -3 -position.

As mentioned above, the needle must be sterilised and then subsequently maintained within the cover to keep it sterilised and this cover must therefore be removed prior to use. Accordingly, the cover may locate within the protective shield so the end portion of the cover projects beyond the protective shield such that a user can grasp and remove the soft cover to enable the injection to be performed. EP 2 533 835 discloses a medical needle cover arrangement in which the furthermost distal end portion of the cover extends through an opening at the furthermost distal end of a telescopic needle shield. The needle shield is telescopically mounted to a carrier such that the needle shield can be retracted proximally to expose the needle. To allow for this telescopic movement, the carrier locates around an outer circumference of a distal end portion of the syringe which increases the diameter of the overall assembly relative to the diameter of the syringe. In addition, the furthermost distal end portion of the cover must extend beyond the furthermost distal end of the needle shield. The length of the needle shield must of course be sufficient to shield the full length of the needle. However, the length of the soft needle cover must be additionally longer than is required for merely covering the needle; so as to allow for this distal extension of the cover to project past the end of the shield, so a user can easily grasp the soft cover to pull it distally forward out from within the rigid needle shield before use (as described in EP 2533835).

Automated methods and systems are used to fill pre-fillable medical syringes, many of which use a tray (nest) and tub arrangement. Such nest and tub arrangements utilise standard size trays (which typically accommodate 160 ready-to-fill syringes per tray and each tray is housed within a standard depth tub) which help to automate standard universal syringe filling systems. However, many safety needle devices integrated onto prefillable syringes cannot be accommodated into a standard nest and tub system without major adaptations to both the tray/nest and the tub. In fact, due to the increased bulk of some designs, only 100 quantity syringes can be fitted into each tray instead of the usual 160 quantity, which not only creates problems -4 -within the automated syringe filling systems, but also greatly increases bulk storage of the packaged syringes per pallet. This invention is suitable for integration onto entirely standard syringes and does not require any modification to either the tray/nest or the tub used within these systems. The sterilisation process may be undertaken whilst the syringes are packaged and contained on pallets and boxes and within the nest and tub arrangements, and so accordingly, the use of standard nest and tub systems can be achieved rather than bespoke systems.

To enable incorporation into standard nest (tray) and tub formats, it is a principal aim of the present invention to minimise the problems discussed above of providing a soft needle cover on a single-use pre-filled syringe having a needle secured to the forward end thereof and in particular to minimise the phenomenon of "pop-off' associated with the manufacture of conventional pre-filled single-use syringes and to simplify the associated automated assembly and filling lines, and ensure the soft needle cover is safely secured during storage of the prefilled syringe It is an aim of the present invention to overcome at least one problem associated with the prior art whether referred to herein or otherwise.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a medical needle cover arrangement comprising: a syringe having a syringe barrel provided with a needle hub at the distal end 25 thereof; a medical needle having a longitudinal axis and a sharp tip, the medical needle being mounted on the needle hub to project distally therefrom; a safety device comprising a needle shield pivotally coupled to a carrier, wherein the carrier is configured to be secured to the syringe, and the needle shield is configured to move outwardly from an initial shielding position to a non-shielding position; a soft needle cover overlying the medical needle to protect the medical -5 -needle and prevent drug leakage from the sharp tip; the soft needle cover comprises, a longitudinal axis, a profile at a proximal end configured to engage a profile on a distal end of the needle hub to create a substantially airtight seal therebetween to maintain the sterility of the enclosed medical needle within the soft needle cover; characterised in that: in the initial shielding position, the soft needle cover is located within the needle shield at a first position, whereat the longitudinal axis of the soft needle cover is aligned with the longitudinal axis of the needle; and whereat a part of the soft needle cover and a pad of the needle shield are configured to engage when the needle shield is at the initial shielding position to releasably maintain the soft needle cover within the needle shield at said first position to prevent drug leakage and maintain the sterility of the medical needle during storage of the syringe; the part of the needle shield engaging the part of the soft needle cover prevents distal movement of the soft needle cover relative to the needle shield away from the first position until the needle shield is moved to the non-shielding position; 20 and wherein the needle shield is arranged to move outwardly away from the soft needle cover and is configured to be manipulated away from the initial shielding position to the non-shielding position; said movement of the needle shield away from the initial shielding position disengages the needle shield from the soft needle cover to thereafter allow (subsequent) detachment of the soft needle cover distally away from said first position to uncover the medical needle.

Preferably the (furthermost) distal end of the soft needle cover is located (entirely) within the needle shield.

Preferably the (furthermost) distal end of the soft needle cover projects/protrudes past the (furthermost) distal end of the needle shield. -6 -

Preferably the needle shield is pivotally coupled to the carrier.

The needle shield may be secured to the carrier by a hinge 5 arrangement/mechanism. The hinge mechanism may define a fixed rotational axis about which the needle shield rotates relative to the carrier. The fixed rotational axis may provide a revolute joint between the needle shield and the carrier.

Preferably the needle shield is arranged to pivot from the initial shielding position to a non-shielding position.

The needle shield may comprise two pivot member which may be engaged within two pivot members on the carrier. The needle shield may comprise two stub axles which may be engaged within two corresponding apertures on the carrier. The pivot members may define a pivoting axis for the needle shield.

The carrier may comprise two pivot member which may be engaged within two pivot members on the needle shield. The carrier may comprise two stub axles which may be engaged within two corresponding apertures on the needle shield. The pivot members may define a pivoting axis for the needle shield.

The needle shield may be arranged to move, and preferably pivotally move, between: the initial shielding position; a non-shielding position; and a final shielding position.

In the final shielding position, the medical needle may be deformed and preferably is non-linear. Preferably with this deformation the medical needle is not re-usable.

As the needle shield is moved from the non-shielding position to the final shielding position, an interior surface of the needle shield is arranged to contact a part -7 - (preferably the sharp tip) of the medical needle. Preferably this contact and the further movement of the needle shield causes the needle shield to subsequently deflect and/or bend the medical needle The needle shield may comprise a resiliently deformable (elastomeric/resilient) locking region, zone or portion to lock the needle shield relative to the carrier in the final shielding position. The locking portion may comprise a proximal region, zone or portion of the needle shield.

The carrier may comprise a locking abutment surface to lock the needle shield relative to the carrier in the final shielding position. The abutment surface may be provided on the carrier as a lug which preferably extends in a distally direction outwardly from the carrier.

The locking portion or region of the needle shield may engage with the abutment surface of the lug in the final shielding position. A sliding surface of the locking portion may be arranged to travel over a sliding surface of the lug when moving from the non-shielding position to the final shielding position. The locking portion and/or the lug may resiliently deform as the locking portion moves over the distal end of locking abutment surface of the lug. In the final shielding position, the locking portion and the abutment surface of the lug are in an undeformed and unstressed (relaxed) condition/state.

A part of the soft needle cover may comprise a step or outer projection or annular flange which may be configured to engage a part of the needle shield which may comprise a (rear/proximally facing) shoulder in order to maintain and hold the soft needle cover over the needle at the first position. Preferably at the first position, the engagement may cause a proximal portion of the soft needle cover to compress and/or expand. Preferably the step may be located spaced and from a proximal distal end of the soft needle cover. Preferably a majority of the soft needle cover is encompassed by the needle shield in the initial shielding position when the cover is at the first position to prevent access to the soft needle cover to prevent the soft -8 -needle cover from being manually grasped and manipulated by the finger(s) of a user. In some embodiments the step may be provided at the extreme furthermost distal end, or the step may actually be formed by the distal end of the soft needle cover. In other embodiments there may be no step and the needle shield may frictionally grip and retain the soft needle cover over the needle at the first position.

The soft needle cover may be (purely/solely) frictionally engaged and/or gripped by the needle shield in order to maintain and hold the soft needle cover at the first position. An outer surface of the soft needle cover may be even (planar) and/or substantially smooth and this outer surface may be frictionally gripped by the needle shield. The needle shield may provide a correspondingly (planar) and/or substantially smooth inner surface in order to grip the soft needle cover. Preferably the movement of the needle shield away from the initial shielding position fictionally disengages the needle shield from the soft needle cover.

The needle shield may comprise a longitudinally extending gap. The needle shield may comprise a partial cylindrical shield in which a longitudinal gap is provided along at least a portion of the longitudinal length and preferably for the full longitudinal length of the needle shield.

The carrier may comprise a ring component. The carrier may comprise a securement member to secure the carrier (and the safety device) to the syringe. The securement member may comprise an internal rib which may be secured to a (rear facing) shoulder provided on the hub of the syringe. The internal rib may comprise a circumferential rib on an inner surface of the carrier and may extend around or partly around the inner circumferential surface of the ring component to encapsulate the needle hub. A part, and preferably an arcuate part of the internal rib may be resiliently movable outwardly to enable a (rear facing) shoulder on the needle hub to pass the internal rib such that the internal rib flexes outwardly and then return towards an original/initial state to thereafter prevent removal of the syringe from the carrier. -9 -

Preferably the part of the needle shield engages the soft needle cover at a location spaced distally forwardly from a rear proximal end thereof when the needle shield is in the initial shielding position to resist movement of the soft needle cover forwardly and distally away from the syringe. The needle shield may encompass a circumferential portion of the outer surface of the soft needle cover and may extend along the entire longitudinal length of the soft needle cover, and the needle shield may extend distally to a position beyond the most distal point of the soft needle cover such that the entire soft needle cover is disposed within the longitudinal length of the needle shield. The length of the soft needle cover from a rear face to the engagement location within the needle shield, is such that by fitting the needle shield and soft needle cover to the syringe, a (rearward) portion of the soft needle cover is subjected to an axial compression force to cause an internal profile of the rearward portion of the soft needle cover to expand resiliently outwards to fit onto a forward part of the syringe hub, thereby ensuring a substantially airtight seal between the resiliently urged end face of the soft needle cover and the needle hub of the syringe.

Preferably a substantially airtight seal is formed between the rear proximal end of the soft needle cover and the forward distal end of the syringe hub by virtue of the axial force and the correspondingly profiled surfaces on the syringe hub acting to cause elastic expansion of the rearward end of the soft needle cover as it is forced onto the syringe hub. Preferably, so long as a safety device including a needle shield for the medical needle is fitted to the syringe to provide the engagement between the soft needle cover and the needle shield, there is no need for the soft needle cover to be held on to the needle hub by mechanical inter-engagement of formations on the needle hub corresponding to inter-engagement formations on the needle cover as is utilised in standard needle covers, such as an in-turned flange which engages behind a rib formed around the bulbous hub of the syringe. Preferably, in this invention, the seal is formed forwardly of any rib or other formation provided on the needle hub of the syringe. Preferably the engagement between the soft needle cover and the needle shield when in the initial shielding position serves to prevent the cover sliding off the needle hub of the syringe from the first position during the manufacturing and sterilisation process or subsequently during storage of the -10 -syringe, by virtue of the fact that the needle shield is restrained against pivotal movement away from the initial shielding position.

The needle shield may comprise clasping means to clasp and/or grip or loosely hold and retain the soft needle cover in the first position. The clasping means may comprise one or more clasps provided on the needle shield and preferably on edges (or adjacent to edges) of a longitudinal gap of the needle shield. The clasping means may provide a restraining force which must be overcome in order to move the needle shield outwardly from the initial shielding position to the non-shielding position. The clasping means (preferably together with the pivotable coupling/hinge mechanism arrangement) may form a sub-assembly comprising the carrier, the needle shield and the soft needle cover and wherein this sub-assembly is maintained and held together as a complete unitary assembly and is preferably self-supporting.

The engagement of the needle shield and soft needle cover during the attachment of the safety device on to the syringe introduces a compressive axial force in the distal direction in the soft needle cover, between a rear end of the soft needle cover and a location where the needle shield engages the soft needle cover. This may urge the rear end of the soft needle cover rearwardly relative to the syringe, to ensure a sterile seal is maintained between the rear end of the soft needle cover and the needle hub. In view of the resilient nature of the soft needle cover, the compressive axial force in a distal direction applied to the soft needle cover may be maintained during manufacture, transport and storage of the syringe, so in turn ensuring that an effective seal is also maintained, even during the sterilisation process which usually subjects the closed void/space around the needle to differential pressure which in turn generates a resultant axial force in the needle cover in a proximal direction.

As with a conventional soft needle cover, the sharp tip of the medical needle may be received in the material of the soft needle cover so as to be sealed thereby. In addition, this confers further protection to the sharp tip of the medical needle in the various stages of the manufacture of the syringe, its sterilisation, packaging, subsequent unpacking for filling, filling and re-packaging.

According to a second aspect of the present invention there is provided a method of protecting a medical needle comprising providing a medical needle cover arrangement which comprises: a syringe having a syringe barrel provided with a needle hub at the distal end thereof; the medical needle having a longitudinal axis and a sharp tip, the medical needle being mounted on the needle hub to project distally therefrom; a safety device comprising a needle shield pivotally coupled to a carrier, wherein the carrier is configured to be secured to the syringe, and the needle shield is configured to move outwardly from an initial shielding position to a non-shielding position; a soft needle cover overlying the medical needle to protect the medical needle and prevent drug leakage from the sharp tip; the soft needle cover comprises, a longitudinal axis, a profile at a proximal end configured to engage a profile on a distal end of the needle hub to create a substantially airtight seal therebetween to maintain the sterility of the enclosed medical needle within the soft needle cover; characterised in that: in the initial shielding position, the soft needle cover is located within the needle shield at a first position, whereat the longitudinal axis of the soft needle cover is aligned with the longitudinal axis of the needle; and whereat a part of the soft needle cover and a part of the needle shield are configured to engage when the needle shield is at the initial shielding position to releasably maintain the soft needle cover within the needle shield at said first position to prevent drug leakage and maintain the sterility of the medical needle during storage of the syringe; the method comprising: -12 -preventing distal movement of the soft needle cover relative to the needle shield away from the first position until the needle shield is moved to the non-shielding position by engaging the part of the needle shield with the part of the soft needle cover; and wherein the needle shield is arranged to move outwardly away from the soft needle cover and is configured to be manipulated away from the initial shielding position to the non-shielding position; said movement of the needle shield away from the initial shielding position disengages the needle shield from the soft needle cover to thereafter allow (subsequent) detachment of the soft needle cover distally away from said first position to uncover the medical needle.

Preferably, in use, the needle shield is initially moved outwardly whilst the needle remains enclosed within the soft needle cover and, once the needle shield is in the outward non-shielding position, the soft needle cover can be grasped by a user and moved distally and detached to uncover the needle in preparation for an injection.

Accordingly, the needle shield prevents access to the soft needle cover to prevent the cover from being removed whilst the needle shield is in the initial shielding position and only/solely allows the soft needle cover to be removable whilst in the non shielding position. In this way, the soft needle cover may remain at the first position until the needle shield is moved to the non-shielding position at which point a user is able to decide when to grasp and remove the soft needle cover. For example, there may be a period of time between moving the needle shield to the non shielding position and the detachment of the soft needle cover.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example only, with reference to the drawings that follow, in which: Figure 1 is a perspective view of a first preferred embodiment of a safety needle assembly and a syringe prior to attachment together; -13 -Figure 2 is a perspective view of the first preferred embodiment of the safety needle assembly attached to the syringe; Figure 3 is a perspective view of the first preferred embodiment of the safety needle assembly attached to the syringe with the protective shield in a non-shielding position and a soft cover removed; Figure 4 is a perspective view of the first preferred embodiment of the safety needle assembly attached to the syringe after an injection with the protective shield in a shielding position; Figure 5 is a perspective view of the first preferred embodiment of the safety needle assembly prior to attachment to a syringe; Figure 6 is a side view of the first preferred embodiment of the safety needle assembly prior to attachment to a syringe; Figure 7 is a top plan view of the first preferred embodiment of the safety needle assembly prior to attachment to a syringe; Figure 8 is a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe prior to attachment together; Figure 9 is a side cross section of the first preferred embodiment of the safety needle 25 assembly and a side view of the syringe attached together; Figure 10 is a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe attached together with the protective shield moving towards a non-shielding position; Figure 11 is a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe attached together with the protective -14 -shield in a non-shielding position and the soft cover removed; Figure 12 is a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe attached together with the protective shield moving towards the shielding position; Figure 13 is a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe attached together with the protective shield in the shielding position; Figure 14 is a detailed view of a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe attached together showing the proximal region of the protective shield in an unlocked position relative to the locking projection; and Figure 15 is a detailed view of a side cross section of the first preferred embodiment of the safety needle assembly and a side view of the syringe attached together with the protective shield in the shielding position showing the proximal region of the protective shield in a locked position relative to the locking projection.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Throughout this specification and with reference to the figures, a safety needle assembly or safety device 8 is shown and described herein which provides for shielding of a sharp tip of a needle 11 of a syringe. As used herein, the term "distal" and/or "forwards" or" forwardly", and derivatives thereof, refer to the direction generally towards the patient end for use, and the term "proximal" and/or "rearwards" or "rearwardly", and derivatives thereof, is used to describe the direction away from the patient during use. As shown in the figures and as will be described, the proximal end of the safety needle assembly attached to a distal end of a syringe 11.

-15 -Referring initially to Figures 1 to 13, there is shown a syringe 10 having a needle 11 staked-in to the nose 12 of the syringe 10 and secured by adhesive, and a safety device 8 to confer protection on the needle 11. The nose 12 of the syringe 8 serves as a hub for the needle 11 and defines a rearwardly facing shoulder 14 and forwardly of that shoulder 14 the nose 12 is provided with a bulbous profile which defines an engagement face 15. Centrally of the nose 12, a small mass of adhesive 16 serves to secure the needle 11 in a bore extending through the nose 12. The safety device 8 includes a carrier 18 in the form of a tubular body or sleeve section for a protective shield 19 (needle shield), movable (specifically, pivotable/tiltable/rotatable) with respect to the needle 11, when an injection is to be performed. The carrier 18 has a bore 20 for the nose 12 of the syringe 10, an inwardly directed rib 21 being formed in the bore 20 for engagement behind the shoulder 14 when the safety device 8 is fitted to the syringe 10 so as to hold the safety device 8 to the syringe 10.

The rib 21 may comprise at least a section of an outwardly flexible rib 21' (as shown in Figure 8) which will flex outwardly during the insertion of the nose 12 into the bore 20. This flexible section 21' includes a sloped inward abutment surface for engagement with the outer circumferential surface of the nose 12. The translational movement of the nose 12 into the bore 20 thereby causes the outer surface of the flexible section 21' to be deflected outwardly until the shoulder 14 projects distally beyond the end of the flexible section 21'. At this position, the flexible section 21' will snap back inwardly to engage the carrier 18 to the nose 12. The corresponding shapes of the shoulder 14 and the distal surface of the rib 21 and flexible section 21' prevent the nose 12 from being withdrawn from the bore 20 in this engaged position. Accordingly, this provides a secure single use snap lock permanent fit for the safety assembly 8 to the syringe 10.

The protective shield 19 is arranged to securely maintain the position of a soft rubber cover 23 within the safety device 8. The cover 23 has a forward portion 24 (distal end) which does not extend beyond the distal end 50 of the protective shield 19.

This provides significant benefits as will be described later. A rearward portion 25 (proximal end) of the cover 23 is disposed within the safety device 8. An -16 -opening/bore 26 extends into the cover 23 from the rearward proximal end 25 thereof, for a distance less than the total length of the needle 11 projecting from the nose 12 of the syringe 10. The external surface of the cover 23 has a step 27 partway between the end 25, which is arranged to engage a rear facing internal shoulder 42 of the protective shield 19. This engagement of the shoulder 42 with the step 27 securely maintains and retains the cover 23 within the protective shield 19 whilst the protective shield is in the initial (before use) position.

In some embodiments, the soft needle cover 23 is purely/solely frictionally engaged and/or gripped by the protective shield 19 in order to maintain and hold the soft needle cover 23 at the first position. In such embodiments, an outer surface of the soft needle cover 23 does not include any step or any similar features for providing a physical and/or mechanical engagement between the soft needle cover 23 and the protective shield 19. This outer surface of the soft needle cover 23 is even/planar and/or substantially smooth and this outer surface is frictionally gripped by the protective shield 19. Similarly, the protective shield 19 does not include a physical/mechanical feature for the engagement but provides a correspondingly planar and/or substantially smooth inner surface in order to frictionally grip the soft needle cover 23. The movement of the protective shield 19 away from the initial shielding position fictionally disengages the protective shield 19 from the soft needle cover 23. As it will be appreciated, in some further embodiments, there may be an element of frictional engagement together with a physical/mechanical feature, such as the step/shoulder arrangement of the preferred embodiment.

A rearward face 28 of the cover 23 within the bore 26 has a profile complementary to that of the (bulbous) engagement face 15 of the nose 12 of the syringe 10. The length of the cover 23 and specifically the positional arrangement of the rearward face 28 relative to the step 27 is such that on press-fitting the safety device 8 to the syringe 10, as shown in Figure 2 and Figure 9, the rearward face 28 engages with the syringe nose engagement face 15 and is thereby expanded resiliently outwardly into engagement therewith by pushing the carrier of the safety device 8 fully home on the nose 12 of the syringe 10. Thus, when the internal rib of the carrier 21 and -17 - 21' is secured to the rear facing shoulder 14 of the hub of the syringe the rearward portion 25 of the cover is subjected to axial compression by the fitting of the safety device 8 to the syringe 10, causing outward radial expansion of the rearward face 28 onto the engagement face 15 of the nose 12 of the syringe to ensure a substantially airtight seal exists or is established between the cover 23 and the nose 12 of the syringe 10, as shown in Figures 2 and Figure 9. Figure 2 shows the syringe 8 has been filled with a drug and the piston and plunger fitted.

The engagement face 15 may be a generally rounded bulbous profile (and/or any other suitable shape) at the nose 12 of the syringe 10 and the rearward face 28 of the cover 23 may have a correspondingly complementary internal profile. These corresponding profiles may provide a substantially airtight hermetic seal between the cover 23 and the syringe 10. The rearward portion 25 of the cover 23 is subjected to a compressive axial force as the safety device 8 is fitted on to the syringe 10 by virtue of the inter-engagement of the step 27 with the internal rear facing shoulder 42 of the protective shield 19 to retain the cover at the first position. Other designs of safety device 8 may be employed, with the cover 23 being modified as appropriate to ensure that the rearward portion 25 of the cover 23 is subjected to a compressive force to establish that the rear end face 28 thereof is in sealing engagement with a corresponding engagement face 15 of the syringe 10, when the safety shield is at an initial position. Such designs that generate a compressive force within the soft needle cover, may cause the engagement face 15 of the syringe to outwardly expand the rear end face 28 of the soft needle cover, or merely cause an end face of the soft needle cover to be in continual compressive contact with a part of the nose/hub end of the syringe, so as to establish and maintain a substantially airtight seal therebetween. In this latter arrangement, a substantially planar or flat face of the soft needle cover 23 may seal against a substantially planar or flat face of the syringe 10 and a compressive force maintains an airtight seal therebetween. Similarly, any other cooperating shaped profiles configured to undergo a compressive force would also establish and maintain an airtight seal therebetween.

In this position, the sharp tip of the needle 11 is sealed to prevent leakage of the -18 -drug by penetrating, to a small extent, into the soft rubber cover 23. This serves to prevent the possibility of drug leakage from the needle 11 and by having only the tip of the needle 11 in the cover 23, the silicon lubricant provided on the needle 11 to assist easy penetration of the needle through the skin will not be wiped away by the cover 23. Further, the inter-engagement of the cover end face 28 with the syringe nose engagement face 15 also effects a seal which ensures the needle 11 also remains in a sterile condition.

When the syringe 10 and safety device 8 are to be used, the protective shield 19 must first be moved to a non-shielding position.

The protective shield 19 includes a pair of stub axles 40 which project inwardly. The carrier 18 includes a corresponding pair of holes 41 for rotatably engaging the stub axles 40. The protective shield 19 is therefore rotatably or pivotably movable relative to the carrier 18. In particular, when the carrier 18 (and thence the safety device 8) is attached to the syringe 10, the protective shield 19 is pivotably movable relative to the needle 11. The protective shield 19 is initially positioned with a longitudinal axis which is generally parallel to the longitudinal axis of the needle 11 and the protective shield 19 is also generally aligned with the needle 11 in this initial configuration.

The protective shield 19 comprises a partial or incomplete longitudinal sleeve section which circumferentially extends only part of the way around the circumferential outer surface of the needle 11. In this way, a longitudinal gap is formed which enables the sleeve section of the protective shield 19 which accommodates and retains the needle cover, to be moved outwardly away from the enclosed needle 11. The protective shield 19 has a distal end 50 which provides the outermost or most distal extent of the safety device 8. Specifically, the distal end 50 of the protective shield 19 extends distally at least the same but preferably beyond the distal end 24 of the cover 23. This forward extent of the shield thereby defines the ideal distal dimension for use with standard nest and tub packaging systems. This negates the need for the cover 23 to be manually grasped for -19 -removal purposes which may be necessary for prior art devices having overly long telescopic protective shields. This distal dimension in the present invention is designed and configured to be equivalent to the dimension of standard needle covers used in existing nest and tub systems, such that no modifications need to be made to the packaging components used in these standard syringe handling assembly lines to accommodate the safety device 8. As will be described, this is further achieved due to the overall diameter of the safety device 8 of the present invention having a diameter to suit existing standard tray/nest and tub systems. The ability to have a needle shield/carrier (safety device 8) which has a diameter no greater than or equal to or less than the diameter of the syringe 10 together with the ability to have the distal most part of the soft needle cover 23 at the distal most part of the protective shield 19 or within the length of shield 19, results in the overall assembled length of the safety device 8 being no greater than non-safety standard needle covers currently used in existing nest and tub systems.

As mentioned above, the protective shield 19 includes an internal shoulder 42 which blocks distal movement of the needle cover 23 away from the first position during assembly of the device 8 onto the syringe 10 and instead urges the cover 23 towards the syringe 10 in the initial position. The present invention advantageously restricts the length of the cover 23 such that the distal most point is defined by the end 50 of the protective shield 19. However, due to this restriction, the cover 23 of the present invention cannot be grasped to remove the cover 23 which is required in order to perform the injection. Accordingly, the protective shield 19 is manipulated manually to move outwardly towards a non-shielding position as shown in Figure 10. This movement causes the shoulder 42 to disengage from the front face 29 of the step 27, and this movement also releases any urging or compressive forces acting on the cover that was pushing the cover towards the syringe 10.

In the outwardly pivoted position shown in Figure 3 and Figure 11, the cover 23 is 30 exposed and can be manually grasped and manipulated by a user and withdrawn from the needle in a distal direction in readiness to perform the injection. With the protective shield in the non-shielding position, the outer surface of the cover 23 is -20 -grasped and pulled distally away from the syringe 10 with the shield in the non-shielding position. The cover 23 is freely moveable in the distal direction since the shoulder 42 of the protective shield 19 is disengaged from the step 27 of the soft cover 23. The cover 23 can therefore be removed as shown in Figure 3 and Figure 11 and can be discarded, with the syringe and safety device ready for performing an injection.

After the injection has been performed, it is necessary to protect the sharp tip of the needle 11. This is achieved through the inward movement of the protective shield 19 into a locked shielding position. In the preferred embodiments, this movement is achieved manually by a user to provide what is termed "active protection" of the sharp tip of the needle 11. The protective shield 19 is pivoted inwardly and an inner surface of the protective shield 19 abuts the end of the needle 11, as shown in Figure 12. The pivotal movement is continued further such that the protective shield 19 bends or deflects/flexes the shaft of the needle 11, as shown in Figure 4 and Figure 13. In this position, the longitudinal axis of the protective shield 19 is angled relative to the longitudinal axis of the syringe 10 and carrier 18. This protects and shields the sharp tip of the needle 11 and also prevents re-use of the needle 11.

In this final shielding position shown in Figure 13, the protective shield 19 is locked in the final shielding position relative to the carrier 18 and syringe 10. During the inward pivotal movement of the protective shield, a proximal region 52 of the protective shield 19 resiliently deforms over a distal edge of the carrier 18 provided by a projection (lug) 54 on the carrier, as shown in Figure 12. The proximal region 52 travels over the projecting lug 54 and eventually passes over the edge of the projection 54. At this point, the resilient properties of the material forming the proximal region 52 may snap back into the original unstressed relaxed state and any deformation of the proximal (abutment) region 52 is released.

The forward (distal) facing abutment surface 55 of the projecting lug 54 may be angled to maintain the protective shield 19 in the locked position. In particular, the forward facing surface 55 may be angled rearwardly from the outer surface to the -21 -inner surface. This angled surface thereby prevents the abutment edge of the resiliently deformable proximal region 52 from being able to travel back over the projecting lug 54 to a non-shielding position. In some embodiments, the rearward facing abutment surface 53 of the proximal region 52 of the protective shield 19 may be angled to maintain the protective shield 19 in the locked position. In some embodiments, both the forward facing surface 55 of the projecting lug 54 and the rearward facing abutment surface 53 of the protective shield 19 are angled to maintain the protective shield 19 in the locked position.

The locking of the protective shield 19 in this final shielding position protects the sharp tip of the needle and the angle of the protective shield 19 also provides an indication that the safety device 8 has been used. Furthermore, the deformation of the shaft of the needle 11 may also serve to prevent the needle 11 from being reused.

Figure 14 and Figure 15 show the locking arrangement of the shield in more detail. The outer surface of the lug 54 comprises a sliding surface 57 over which a part of the protective shield 19 is arranged to move during movement of the shield to the locked position. The inner surface of the protective shield 19 provides a sliding surface 56 in order to aid the sliding movement of the protective shield 19 to the locked final shielding position. In particular, the inner sliding surface 56 of the protective shield 19 is arranged to slide over the outer sliding surface 57 of the lug 54. To move to the locked position, the protective shield 19 is pivoted relative to the carrier 18 which causes the sliding surfaces 56, 57 to move relative to each other such that the sliding surface 56 of the protective shield 19 slides over the sliding surface 57 of the lug 54. The sliding surface 56 of the protective shield 19 (sliding on the sliding surface 57 of the lug 54) then reaches the distal edge of the projection (lug) 54 and the rotational force applied by the user to move the shield to the protecting position, causes a zone within the proximal region 52 of the protective shield 19 to deform outwardly relative to an adjacent zone within the proximal region 52 of the protective shield 19. The deformable zone and the adjacent zone are provided on a continuous (and homogenous) portion of the protective shield 19.

-22 -The proximal region 52 of the protective shield 19 provides a deformable zone and comprises resilient/elastic properties. In some embodiments, this zone or region may comprise a reduced thickness (i.e., a relatively thin zone/region) or have a tapered sectional thickness to provide the required deformable properties for this zone/region of the proximal region 52. The protective shield 19 would typically comprise a moulded plastics material or polymer material to provide the required resilient elastic properties. The material may comprise a thermoplastic material having resilient deformable plastic properties which enable the proximal region 52 to deform outwardly during the movement of the protective shield 19 to the locked position and the lug 54 may have a profile shaped to cause said outward deformation of the region 52. The material and/or the dimensions in this zonal region allow and permit the elastic deformation in order to allow movement the protective shield 19 to the locked position. As shown in Figure 15, in the final shielding locked position, the prior deformation of the proximal region 52 has dissipated and the proximal region 52 is in its undeformed and unstressed original relaxed condition or state. In particular, in this locked position, a gap 59 may be defined between the contact or abutment faces 53, 55 of the protective shield 19 and the lug 54, as shown in Figure 15. This demonstrates that the deformation of the proximal region 52 has dissipated and the proximal region 52 and the associated adjacent zones has returned to its original relaxed condition/state. Furthermore, the (complementary angled) end abutment faces 53, 55 of the protective shield 19 and the lug 54 engage to prevent pivotable return movement of the protective shield 19 towards a position in which the needle 11 may be exposed and present a hazard.

The protective shield 19 may include grip portions 46, 47 on the outer surface to aid the manual manipulation of the protective shield 19, as shown in Figure 5, Figure 6 and Figure 7. These grip portions 46, 47 may comprise ribs extending on the outer surface. The protective shield 19 may have a pair of front or distal ribs 46 and a pair of rear or proximal ribs 47. Each pair providing two ribs 46, 47 offset by approximately 180 degrees around the outer circumference of the protective shield 19. The protective shield 19 also comprises retaining means in the form of retaining -23 -clasps 44 to maintain the protective shield 19 in the initial position, as shown in Figure 5 and Figure 6. These retaining clasps 44 comprise shaped lugs having inner arcuate surfaces to locate around a part of the outer circumferential surface of the cover 23 to either grip or loosely hold the cover 23. As shown in Figure 5, the two clasps 44 are spaced apart to provide a release gap therebetween. The extent of this release gap is less than the outer diameter of the cover 23. However, this cover 23 is made from a resiliently deformable material such that the cover 23 in this area can be deformed sufficiently to enable the cover 23 to pass through the release gap during use. The extent of this force is controlled by the size of the release gap and the material of the cover 23. In particular, the release force is controlled to be sufficient to prevent any accidental and inadvertent movement of the protective shield 19 from this initial position but to allow a user to still move the protective shield 19 to the open position relatively easily albeit with some resistance.

The clasps 44, together with the pivotable coupling/hinge mechanism arrangement, form a sub-assembly comprising the carrier 18, the protective shield 19 and the soft needle cover 23 and this sub-assembly is maintained together as a unitary assembly and is preferably self-supporting. The creation of the sub-assembly helps with the handling and fitting of the device onto a syringe.

Overall, the present invention provides a safety needle device 8 which can be used within standard nest and tub systems due to the dimensions (length and diameter) of the safety device 8 to replace ordinary non-safety needle cover devices. The protective shield 19 is pivotable from an initial position in which the cover 23 has a proximal portion which is axially compressed during assembly of the device 8 on to the syringe 10 and is urged to create a seal against the nose 12 of the syringe 10. In this initial position, the cover 23 cannot be accessed or grasped and removed by a user without the user first pivoting the protective shield 19 outwardly which then exposes the cover 23 to allow a user to grip and pull off the cover 23 to expose the needle 11 ready for an injection. Once the injection has been completed, the protective shield 19 is pivoted inwardly until it contacts and then flexes or bends the needle 11 away from its central longitudinal axis. The protective shield 19 then -24 -automatically engages and locks in the final shielding position with the needle 11 and the protective shield 19 being maintained at an angle offset from the longitudinal axis of the syringe 10.

The present invention may be used with pre-filled or pre-fillable syringes. In summary, the present invention provides a safety needle device for a syringe to replace non-safety standard needle covers and which does not require bespoke or modified nest/tray and tub systems and can be integrated into entirely standard tray/nest and tub designs.

A profile at the proximal end of the device 8 is configured (shaped) to engage a profile on the distal end of the needle hub to affect a substantially airtight seal therebetween to maintain the sterility of the medical needle and prevent drug leakage through the needle from within the syringe. The soft needle cover is located within the protective shield/needle shield, such that when the needle shield is at the initial shielding position the axis of the soft cover is generally coaxial with the axis of the medical needle. A part of the soft needle cover and a part of the needle shield are configured to engage when the shield is at the initial shielding position to (or resist distal movement of the needle cover relative to the protective shield) and releasably maintain the needle cover at a first position within the shield to prevent drug leakage and maintain the sterility of the needle during storage of the syringe. The part of the needle shield engaging a part of the soft needle cover blocks/prevents distal movement of the soft needle cover relative to the needle shield away from a first position until the needle shield is moved to a non-shielding position. The needle shield is arranged to pivot outwardly (with respect to the axis of the syringe body) and is configured to be manipulated (by a user) away from the initial shielding position to a non-shielding position. This manipulation of the needle shield away from the initial shielding position, disengages the needle shield from the soft needle cover in a radially outward arcuate direction and continued movement of the shield to a non-shielding position (then) allows complete detachment of the needle cover from the syringe and needle. Once the injection is completed and the drug has been delivered, the needle shield can be (manipulated) and moved to the (locked) final needle shielding position.

Claims

-25 -CLAIMS1. A medical needle cover arrangement comprising: a syringe having a syringe barrel provided with a needle hub at the distal end 5 thereof; a medical needle having a longitudinal axis and a sharp tip, the medical needle being mounted on the needle hub to project distally therefrom; a safety device comprising a needle shield pivotally coupled to a carrier, wherein the carrier is configured to be secured to the syringe, and the needle shield is configured to move outwardly from an initial shielding position to a non-shielding position; a soft needle cover overlying the medical needle to protect the medical needle and prevent drug leakage from the sharp tip; the soft needle cover comprises, a longitudinal axis, a profile at a proximal end configured to engage a profile on a distal end of the needle hub to create a substantially airtight seal therebetween to maintain the sterility of the enclosed medical needle within the soft needle cover; characterised in that: in the initial shielding position, the soft needle cover is located within the needle shield at a first position, whereat the longitudinal axis of the soft needle cover is aligned with the longitudinal axis of the needle; and whereat a part of the soft needle cover and a part of the needle shield are configured to engage when the needle shield is at the initial shielding position to releasably maintain the soft needle cover within the needle shield at said first position to prevent drug leakage and maintain the sterility of the medical needle during storage of the syringe; the part of the needle shield engaging the part of the soft needle cover prevents distal movement of the soft needle cover relative to the needle shield away from the first position until the needle shield is moved to the non-shielding position; and wherein the needle shield is arranged to move outwardly away from the soft needle -26 -cover and is configured to be manipulated away from the initial shielding position to the non-shielding position; said movement of the needle shield away from the initial shielding position disengages the needle shield from the soft needle cover to thereafter allow subsequent detachment of the soft needle cover distally away from said first position to uncover the medical needle.
2. A medical needle cover arrangement according to Claim 1 in which the furthermost distal end of the soft needle cover is located within the needle shield.
3. A medical needle cover arrangement according to Claim 1 in which the furthermost distal end of the soft needle cover projects/protrudes past the furthermost distal end of the needle shield.
4. A medical needle cover arrangement according to any preceding claim in which the needle shield is secured to the carrier by a hinge mechanism.
5. A medical needle cover arrangement according to Claim 4 in which the hinge mechanism defines a fixed rotational axis about which the needle shield rotates relative to the carrier.
6. A medical needle cover arrangement according to any preceding claim in which the needle shield is arranged to pivot from the initial shielding position to the non-shielding position.
7. A medical needle cover arrangement according to any preceding claim in which one of the needle shield or carrier comprises two pivot member which are engaged within two pivot members on the other of the needle shield or carrier.
8. A medical needle cover arrangement according to any preceding claim in which the needle shield is arranged to pivotally move, between: the initial shielding position; the non-shielding position; and -27 -a final shielding position.
9. A medical needle cover arrangement according to any preceding claim in which in the final shielding position, the medical needle is deformed and is non-linear.
10. A medical needle cover arrangement according to any preceding claim in which, as the needle shield is moved from the non-shielding position to the final shielding position, an interior surface of the needle shield is arranged to abut a part of the medical needle and this abutment and further movement of the needle shield causes the needle shield to subsequently deflect and/or bend the medical needle.
11. A medical needle cover arrangement according to any preceding claim in which the needle shield comprises a deformable locking portion to lock the needle shield relative to the carrier in the final shielding position.
12. A medical needle cover arrangement according to Claim 11 in which the locking portion comprises a proximal region of the needle shield.
13. A medical needle cover arrangement according to Claim 11 or Claim 12 in which the carrier comprises a locking surface to lock the needle shield relative to the carrier in the final shielding position and the locking surface is defined on a distally extending projection.
14. A medical needle cover arrangement according to Claim 13 in which the locking portion is arranged to travel over the locking surface when moving from the non-shielding position to the final shielding position and, in which, the locking portion resiliently deforms as the locking portion moves over the locking surface.
15. A medical needle cover arrangement according to any one of Claim 11 to Claim 14 in which, in the final shielding position, the locking portion is in an undeformed and relaxed state.
16. A medical needle cover arrangement according to any preceding claim in which the part of the soft needle cover comprises a step which is configured to engage the part of the needle shield which comprise a shoulder in order to maintain the soft needle cover over the needle at the first position.
17. A medical needle cover arrangement according to any one of Claim 1 to Claim 15 in which the soft needle cover is frictionally engaged and gripped by the needle shield in order to maintain and hold the soft needle cover at the first position, wherein an outer surface of the soft needle cover is substantially smooth and this outer surface is frictionally gripped by the needle shield and, in which, the movement of the needle shield away from the initial shielding position fictionally disengages the needle shield from the soft needle cover.
18. A medical needle cover arrangement according to Claim 16 or Claim 17 in which the engagement compresses and/or expands a proximal portion of the soft needle cover.
19. A medical needle cover arrangement according to any preceding claim in which the needle shield comprises a partial cylindrical shield in which a longitudinal gap is provided along full longitudinal length of the needle shield.
20. A medical needle cover arrangement according to any preceding claim in which the part of the needle shield engages the soft needle cover at a location spaced forwardly from a rear end thereof when the needle shield is in the initial shielding position to resist movement of the soft needle cover forwardly and distally away from the syringe.
21. A medical needle cover arrangement according to any preceding claim in which the needle shield encompasses a circumferential portion of the outer surface of the soft needle cover and extends along the entire longitudinal length of the soft needle cover.
22. A medical needle cover arrangement according to any preceding claim in which the needle shield extends distally to a position beyond the most distal point of the soft needle cover such that the entire soft needle cover is disposed within the longitudinal length of the needle shield.
23. A medical needle cover arrangement according to any preceding claim in which the length of the soft needle cover from a rear face to the engagement location with the needle shield, is such that by fitting the needle shield and soft needle cover to the syringe, a portion of the soft needle cover is subjected to an axial compression force to cause an internal profile of the rearward portion to expand radially outwards over a forward part of the syringe hub, thereby ensuring a substantially airtight seal between the resiliently urged end face of the soft needle cover and the needle hub of the syringe.
24. A medical needle cover arrangement according to any preceding claim in which a seal is formed between the rear end of the soft needle cover and the forward end of the syringe by virtue of the axial force and the correspondingly profiled surfaces on the syringe and soft needle cover.
25. A medical needle cover arrangement according to any preceding claim in which the needle shield comprises clasping means to clasp the soft needle cover in the first position.
26. A medical needle cover arrangement according to any preceding claim in which the clasping means comprises one or more clasps provided on or adjacent to edges of a longitudinal gap of the needle shield.
27. A medical needle cover arrangement according to Claim 25 or Claim 26 in which the clasping means provides a restraining force which must be overcome in order to move the needle shield outwardly from the initial shielding position to the non-shielding position.-30 -
28. A method of protecting a medical needle comprising providing a medical needle cover arrangement which comprises: a syringe having a syringe barrel provided with a needle hub at the distal end 5 thereof; the medical needle having a longitudinal axis and a sharp tip, the medical needle being mounted on the needle hub to project distally therefrom; a safety device comprising a needle shield pivotally coupled to a carrier, wherein the carrier is configured to be secured to the syringe, and the needle shield is configured to move outwardly from an initial shielding position to a non-shielding position; a soft needle cover overlying the medical needle to protect the medical needle and prevent drug leakage from the sharp tip; the soft needle cover comprises, a longitudinal axis, a profile at a proximal end configured to engage a profile on a distal end of the needle hub to create a substantially airtight seal therebetween to maintain the sterility of the enclosed medical needle within the soft needle cover; characterised in that: in the initial shielding position, the soft needle cover is located within the needle shield at a first position, whereat the longitudinal axis of the soft needle cover is aligned with the longitudinal axis of the needle; and whereat a part of the soft needle cover and a part of the needle shield are configured to engage when the needle shield is at the initial shielding position to releasably maintain the soft needle cover within the needle shield at said first position to prevent drug leakage and maintain the sterility of the medical needle during storage of the syringe; the method comprising: preventing distal movement of the soft needle cover relative to the needle shield away from the first position until the needle shield is moved to the non-shielding position by engaging the part of the needle shield with the part of the soft -31 -needle cover; and wherein the needle shield is arranged to move outwardly away from the soft needle cover and is configured to be manipulated away from the initial shielding position to the non-shielding position; said movement of the needle shield away from the initial shielding position disengages the needle shield from the soft needle cover to thereafter allow subsequent detachment of the soft needle cover distally away from said first position to uncover the medical needle.