The present invention relates to protective devices for medical and other sharps devices, such as hypodermic needles and syringes. Hypodermic needles, syringes and the like have long presented a medical hazard to their users. This is on account of the presence of a sharp point at the end of a needle intended to pierce/puncture a subject's skin to deliver the contents of a syringe or to obtain a sample, for example.

Healthcare workers and patients using such devices are potentially at risk from exposure to, for example, bacteria, viruses, prion proteins, blood, body fluids or the like. Whilst not all blood or body fluids are potentially infective, it is advisable that precaution be taken to reduce the risk of infection as exposure to blood or potentially infectious body fluids may result in the transmission of blood borne viruses (BBVs) which include, HIV, Hepatitis, CJD, amongst many other things. Following the European Council Directive 2010/32/EU the UK designated

implementer, the HSE, produced the Health and Safety (Sharps Instruments in Healthcare) Regulations part of which included the legal position that required the substitution of traditional unprotected sharps with a 'safer sharp' when reasonably practicable. The European Union Council in adopting rules for the prevention of sharps injuries state that there are one million plus of such injuries in Europe per annum. The rules were adopted as law by the member states in 2013.

Further, the environment in which the procedure requiring such devices occurs may not be sterile and inadvertent contamination of the needle, for example, by bacteria and/or viruses from the surrounding environment may occur and be inadvertently introduced into a patient.

It is therefore advantageous to manage the sterility and/or health risk of the needles of such devices to patients using such devices themselves, but also healthcare workers.

In accordance with a first aspect of the present invention, there is provided a protective device for a needle device, the needle device having a needle and a body upon which the needle is mounted, the protective device comprising:

A) a housing having a closed end and an opening for receiving both the needle and at least a portion of the needle device body;

B) retaining means for engaging with and retaining the protective device in position with respect to a needle device when in situ.

The present invention thus provides a means for protecting against sharps injuries before, during or after a procedure when a needle device is not being used. Any "ooze", i.e. a droplet of blood or bodily fluid that drips from the end of the needle after an injection due, for example, to the release of pressure on a rubber bung in a cartridge-based needle device is completely and safely contained within the protective device if the needle device is received therein. Furthermore, any "spatter" i.e. any aerolisation of blood or bodily fluids caused by the use or engagement of the protective device (i.e. the vibration of a needle caused by the action of engaging the device) is also safely contained within the protective device and cannot enter the atmosphere or land on other instruments, for example. In an embodiment, the needle device is capable of penetrating a substrate and establishing fluid communication between the needle device and the substrate for transfer of fluid therebetween.

The protective device may be fabricated inexpensively from a suitable synthetic polymer. The protective device may be provided as a stand-alone device which is installed on a needle device, or alternatively, may be formed as part of the needle device.

The protective device may comprise a single piece cylinder moulding.

In an embodiment, the housing comprises an elongate substantially cylindrical body closed at one end. This closed end may be adjacent to and covers the sharp point of the needle when it is either temporarily parked or permanently contained and/or degraded.

The opening for receiving the needle and at least a portion of the needle device body comprises a wide elongated opening complementarily shaped to receive the syringe needle and needle device body.

In an embodiment, extending toward the rear of the protective device is a slot. The slot may be shaped to provide two retention members for engaging with a needle device body and retaining in situ a needle device.

The slot may have double thickness walls with respect to the thickness of the remainder of the wall of the housing, and as such may act as a circular spring that the needle device can open as it is pressed down and then pass through it into the housing where it is firmly gripped by the then closing spring. The protection device may comprise support means for supporting the device in a suitable position for use and to assist in maintaining correct orientation and ease of use. The support means may comprise one or more support feet.

The support feet may comprise a rail extending longitudinally with respect to the protective device's longitudinal axis. The support feet may comprise one or more feet extending transversely with respect to the protective device's longitudinal axis.

Suitably the support means comprise one or more longitudinal and transverse rail. Suitably, the protective device comprises two longitudinal and two transverse rails. More suitably, the one or more transverse rail is located adjacent to the retaining means.

The support means assists in one handed use of a needle device and the protective device avoiding movement of the protective device relative to the needle device during use.

The closed end of the housing is puncture proof with respect to a needle. In accordance with a further aspect of the present invention, there is provided a needle device assembly comprising a needle device and a protective device, the needle device comprising a needle for penetrating a substrate and establishing fluid communication between the needle device and the substrate for transfer of fluids therebetween, operatively connected to a housing wherein the housing comprises at one end adjacent/proximal to the needle one member of a mating/retaining pair; the protective device as described hereinabove further comprising a second member of a retaining pair, for engaging with and retaining the needle device body. The protective device and/or needle device may comprise two or more retaining members. Suitably the needle device comprises two members of a first and second retaining pair for cooperation with two members of the first and second retaining pair disposed on the protective device. The members of the retaining pair may comprise one or more protrusions. Suitably they comprise circumferentially extending protrusions. In an embodiment, the needle device has two circumferentially extending protrusions on its body proximal to the needle. The rear protrusion, with respect to the needle, may act for reversible retention enabling the needle device to be removed from the protective device for re- use. The front protrusion may act as a permanent retention of the needle device within the protective device.

The protrusions may suitably have a semi-circular cross-section.

In an embodiment the housing may be tapered towards its closed end to aid in permanent retention of the needle device when in this configuration. The needle device may include a syringe body to which a needle may be affixed.

In accordance with a further aspect of the present invention, there is provided a syringe device for delivering a hypodermic injection comprising a housing having a chamber for receiving a cartridge containing a fluid and having at one end a diaphragm intended to be punctured to permit the fluid to be delivered, wherein the housing is resiliently deformable and the device comprises means to deform at least a portion of the housing when inserting a cartridge into the chamber.

The means to deform the housing may comprise a loading arch which extends across the chamber (opening). The arch and housing may define a viewing window for aspirant. The window may be located proximal to the diaphragm of the cartridge when it is inserted into the device.

The means may further comprise a slot disposed in the housing. Suitably the slot is cruciform and permits the housing to deform more easily in response to the insertion of a cartridge into the chamber.

Further the means may comprise one or more guide members to help guide the cartridge into the chamber and correct alignment. The one or more guide members may further comprise cartridge retention means.

In accordance with a further aspect of the present invention, there is provided a device for delivering a hypodermic injection comprising a chamber for receiving a cartridge containing a fluid having at one end a diaphragm intended to be punctured to permit the fluid to be delivered, wherein the device comprises means to effect aspiration capable of interacting with the diaphragm of the cartridge such that aspiration can occur. In accordance with a further aspect of the present invention, there is provided a device for delivering a hypodermic injection comprising a housing having i) A chamber to receive a cartridge containing fluid and having a moveable bung, ii) a plunger axially movable and in use capable of interacting with said bung to move it, said plunger having resiliently deformable means for engaging with said bung. The present invention will now be described by way of example only with reference to the accompanying figures, in which:

Fig. 1 shows upper side of a protective device in accordance with the present invention; Fig. 2 shows the lower side of the protective device of Fig. 1 ;

Fig. 3 a and b are partial sectional views showing location of a needle device in a protective device in accordance with the present invention;

Fig. 4 shows the housing of a needle device in accordance with the present invention;

Fig. 5 shows the housing of Fig. 4 from the side with an enlarged sectional view of a portion of the loading arch in accordance with the present invention;

Fig. 6 shows a perspective view of the housing of Figs. 4 and 5;

Fig. 7 shows a rear view of the housing of Figs. 4, 5 and 6; Figs. 8 a to c show a plunger for a needle device in accordance with the present invention;

Figs. 9 a to d show the housing of a needle device in accordance with the present invention having a cartridge inserted and positioned in place; and

Figs. 10 a to c show aspirating means in accordance with the present invention. Figs. 1 and 2 show a protective device 10 having a substantially cylindrical body 14 open at one end 16 and closed at the other 18. Cylindrical body 14 has an inner wall 20 and outer wall 22. The open end 16 has a longitudinal slot 24 on the upper surface of the cylindrical body 14 extending towards the closed end 18 and which terminates approximately halfway towards the closed end 18. The slot 24 narrows toward the open end 16 forming two syringe body retention members 25' and 25",.

The lower surface of the cylindrical body 14 has two spaced rails 26, 28 extending longitudinally along substantially its length. Towards the open end and adjacent to the retention members 25', 25" are two transverse rails 30, 32 which support the protective device in use.

Disposed on the inner wall of the cylindrical body are two spaced apart

circumferentially extending protrusions 34,36 (protrusion 36 indicated by a dotted line in Fig. 1 ) which extend inwardly from the inner surface of the body

Figs. 3a and b show the positioning of the needle device passing through the retaining tabs of the protective device with a vertical push down where it is locked in an intermediate position.

In use, it should be remembered that medical and dental operatives are used to putting the needle sheath on its removal from the needle just prior to injection, in a set position for subsequent retrieval. However this time the technique used is single- handed.

Thus when the protective device is taken from the needle device, e.g. syringe, it is placed in the same convenient position as is the sheath, that is directly where the operatives hand would fall as the syringe and attached needle is removed from the patient. For health and safety reasons it is advisable not to stand or walk about with an exposed needle in the operative's hand. The operative should be in such a position that the operative is not required to walk to the protective device.

On giving the injection the operative with one hand takes the contaminated syringe to the protective device which is in close proximity. The needle is passed through the loading opening and should touch its upper front end (see diagram) with the upper needle face. This prevents the needle tip touching the inner surfaces of the protective device. The needle hub is pushed forwards until it is approximately 3mm from the front edge of the opening. With the index finger the operative presses straight down on the syringe hub. This action in pushing through the syringe receiver slot causes the clip to open and the syringe passes through. As this happens the clip closes above the syringe and it is temporarily retained by the rear circumferential rings and the clip friction. If a top up injection is subsequently required it is simple to unclip the protective device with one hand, putting it in the same recovery position as before, giving the injection and then recovering it as with the primary injection. This can be repeated.

Replacing a cartridge is as simple, but only done in those countries where it is permitted. The needle remains covered and protected during this procedure. When the injection is to be given with the new cartridge, it is removed as for a top up injection.

When satisfied that all injections are complete, and this could of course be the first injection, the syringe and needle are pressed down vertically into the protective device with the front end placed on a firm surface. The syringe passes forwards further into the protective device, the needle point strikes the puncture proof forward end of the protective device and bends in such a way that the needle is degraded to such an extent that is unusable.

The protrusions on the syringe itself travel over the first protrusion of the protective device and into the internal taper. The combination of these two lock the syringe and disabled needle permanently into the front chamber of the protective device.

Glass type medical syringes can also be used with the protective device.

In an embodiment, the syringe may not have a protrusion as described above but rather a tapered body. In such an embodiment the protective device has a

complementarily shaped internal tapered sidewall and no internal protrusions. Fig. 4 shows a needle device body 50, in this case a syringe without a needle, having a substantially cylindrical body 52 having at one end means for mounting a needle 54 and at the other an open end 56 for receiving a plunger. There is a longitudinal slot 58 in the body 52 for receiving a cartridge of a drug or the like to administer to a patient and gripping members 60, 62 economically shaped to accommodate the digits of a user to assist in better control to depress or retract a plunger (not shown) in use. Extending over the slot 58 is loading arch 70 having a first sidewall 72 substantially perpendicular to the longitudinal axis of the needle body and a second side wall 74 being arcuate and having a concave profile (Fig. 5). The loading arch has an upper 76 and lower 78 surface and side wall 74 is chamfered from the upper surface towards the lower surface to facilitate easier loading of a syringe cartridge.

Located at one end, adjacent to the mounting for a needle 54 are two spaced apart circumferentially extending protrusions 64, 66. The protrusions 64, 66 are spaced apart to be capable of engaging with the spaced apart protrusions 34, 36 of the protective device 10.

Figs. 6 and 7 show the needle device body 50 having a cruciform slot 90 disposed towards the end of the needle device body having the mounting 54. The cruciform slot is composed of a narrow longitudinal slot 92 extending along the longitudinal axis of the needle body 50 and a narrow transverse slot 94 extending along the transverse axis of the needle body. The transverse slot 94 is adjacent to the loading arch 70 to facilitating bending of the cylindrical body 52 when inserting a cartridge. Located at the distal end of the syringe body, relative to the needle mounting 54 is the plunger rod support member 80. The support member 80 comprises four petals 82 each of which extend away from the cylindrical syringe body and are equidistantly arranged circumferentially. Each petal 82 has a substantially perpendicular return 84 which extends circumferentially outward, away from the cylindrical body 52. Figs. 8a to c show a plunger 96 for use in a needle device in accordance with the present invention. The plunger 96 has an elongate body 97 having a cruciform transverse section. At one end it has a narrow shaft 100 at the end of which are four leaves 96 in a substantially cruciform arrangement. At the other end, distal from the syringe body in use and extending circumferentially is a plunger rod end 98 for engaging with the thumb of a user in use.

The leaves 96 of the plunger are resiliently deformable such that they can be deflected when pushed against a cartridge. Cartridges used for device such as those described in the present invention typically have an elongate hollow cylindrical body at one end having means for engaging with a perforator of a needle device at the needle mounting end of a syringe and at the other, distal, end a recess in which is inserted a plug which a plunger rod will engage. Around the internal circumference of the cartridge body's distal end is a small lip which extends inwardly towards the centre of the cartridge body. The lip is formed during manufacture as the cylindrical body is formed. Consequently, the plunger rod has to be of a smaller diameter than the lip of the cartridge body. In known devices, in practice this requires there to be a separate deformable collar to be applied to the end of the plunger rod so that the plunger rod can be used to deliver the cartridge's contents.

Most known plunger rods comprise 3 components: a plunger rod itself, a flexible collar and thumb piece - the slider assembly includes finger grips and is separate and greatly increases the length making it difficult for operatives with small hands to use.

In contrast, the plunger rod of the present invention can be formed as a single piece reducing the manufacturing and assembling costs associated with such devices. The plunger rod of the present invention has resiliently deformable leaves which extend slightly beyond the internal circumference of the lip of a cartridge and can thus be pushed therethrough. The leaves will then attempt to conform to their original shape and push against and be retained by the circumferential lip. In this way the rod is held in place and can be depressed and retracted. Figs. 9a to d show a cartridge 1 10 being loaded into a needle device in accordance with the present invention. The cartridge 1 10 has a diaphragm 1 12 at one end which is presented to the perforator 1 14.

When used with a dental cartridge syringe the needle device is designed to allow not only the initial loading but also any subsequent top-up injections that can involve the cartridge to be changed one or more times. To do this successfully the protective device may hold the syringe in such a way as to allow the reloading cartridge to travel along the longitudinal axis of the syringe so that the perforator diaphragm presents to the needle perforator at a right angle. This prevents tearing of the rubber-like material of the diaphragm and subsequent leakage. The protective device with one hand holds the anterior end of the syringe body along the longitudinal axis, protecting the operative from needle stick injury but still allowing the rear end of the syringe to bend thus opening the one-part breech and allowing the loading of a cartridge. To achieve loading the directional forces of the loading of the cartridge are such as to, in combination with the syringe loading arch and the syringe securing clips, open the breech automatically. Effectively it opens the breech to the correct bend angle by allowing the cartridge front end to pivot around the loading arch whilst applying a downward pressure on the securing clips.

The cartridge can then move forward along the longitudinal axis and is held at this angle by the loading clip so that the perforator diaphragm is perpendicular to the needle perforator tip at contact.

To achieve this it is essential that the loading arch is positioned at a set length from the needle perforator tip.

The bending of the syringe body, this is in effect the opening of the breech, is greatly facilitated by the two slots positioned on the syringe body underside and forming a cross. Both serve to aid the action of bending and preventing stress damage to the material. The transverse slot allows for compression of the material by simply opening as the syringe bends whilst the longitudinal slot opens. It also allows opening flexure of the receiving opening's longitudinal walls.

The transverse slot ensures the bending motion occurs at the correct position, that is the loading arch.

To load (as shown in Figs. 9a to d) such a device, the syringe body is held in one hand with the fingers squeezing the outer sides of the protective device and this in turn increases the grip on the anterior portion of the syringe. With the other hand the cartridge is placed with its metallic perforator end hooked under the loading slot and to the rear the underside of the cartridge body resting on the syringe securing clips. At this moment the syringe is still straight with the cartridge at an angle to the longitudinal axis. One finger is placed on the top and to the very rear of the cartridge and pressure is applied downwards and forwards.

The rear downward pressure onto the loading clips by the underside of the cartridge in conjunction with the perforator end of the cartridge being hooked under the loading arch, causes the rear of the syringe to start to bend at the transverse slot and for the longitudinal slot to also start to close and allow the walls of the loading opening to widen and facilitate loading.

As the cartridge reaches the longitudinal axis position it at the same time starts to move forward and is then held on this axis by the loading arch. The two forces downwards and forwards cause the cartridge to open the breech sufficiently for the cartridge to move forwards under the loading arch with its perforator diaphragm presenting at the prescribed right angle to the tip of the needle perforator. The perforator ends have angled cutting ends as does the needle end and they are non- coring, to ensure this function that prevents needle blockage and false aspiration reading, the needle must penetrate the diaphragm at right angles and without rotating when it would cut out a plug. This is the further reason for the right angle approach and for putting the needle on first.

The cartridge continues forwards, the diaphragm is pierced by the needle perforator and comes to rest on the inside anterior of the syringe.

The posterior end of the cartridge is then squeezed with a downward pressure through the securing clips and the syringe is now in the injection configuration.

As the cartridge passes through the clips its correct closure is indicated by a distinct click. In addition visually the breech is either open or closed. Should the breech be left open, and this is extremely unlikely, then as the plunger rod will not load the syringe cannot be activated.

Towards the posterior end of the syringe at the opening of the plunger rod slider assembly is an internal circumferential ring that prevents the rear of the cartridge slipping backwards into the assembly and preventing the breech from opening during an unloading procedure.

Figs. 10 a to c show aspirating means 120 in accordance with the present invention.

Provided at the end of the longitudinal slot 58 proximal to the needle mounting member 54 and extending away towards the interior of the longitudinal slot 58 is a protrusion 122 shaped to engage with the diaphragm 102 of a cartridge 100. The protrusion 122 is mounted on a stop 124, this stop is wider than the opening on the metal cap 126 that permits the perforator 128 to reach the cartridge diaphragm 102. The cartridge is free to move backwards and forwards within the syringe body. The volume of the protrusion is such that a specific volume of aspirant can be drawn. In a one-handed action the protrusion 122 of the syringe acts along the longitudinal axis of the syringe body and of its continuation, the plunger rod. The main problem of the high vacuum pull-back method of aspiration of known devices is the displacement of the needle tip backwards and forwards between the aspiration and injection resulting in a false negative. The other lesser problem of known devices is transverse movement. This is partly negated by the Passive Aspirating function being one-handed but can also be aided by a simple adaptation of the cartridge diaphragm itself.

In the present invention, (fig. 10c) within the opening 130 on the front face of the cartridge that primarily accepts the perforator of the needle is a circular concave indent in the diaphragm 129 that is continuous with a raised outer half ring the combined forming a part entry into the diaphragm interior.

The face 131 of protrusion 122 which contacts the diaphragm 102 is convex and faces the concavity of the diaphragm opening. The protrusion 122 is slightly wider than the diaphragm opening so that in function as the cartridge 100 moves forwards against the wider protrusion 122 drives itself into the smaller diaphragm opening, causing lateral radial stretching of the diaphragm 102 as well as the longitudinal function.

On release of the plunger rod pressure all activating forces are released springing the diaphragm back to the central start point preventing both longitudinal and transverse radial displacement.

The diaphragm opening can be a simple indent or a raised ring shape or, as shown in the Figs. 10 a to c, a combination of the two. The protrusion 122 is wider than the concavity of the diaphragm opening. In an alternative embodiment, the diaphragm may be at the end of the cartridge that is proximal to the plunger rod and the plunger rod has a protrusion for contacting the diaphragm. The protrusion in such an embodiment is located at the end of the rod proximal to the cartridge in use.

In another embodiment, the cartridge syringe has both front and rear diaphragms and the syringe has a protrusion on the plunger rod and the syringe body, as described above. In a further embodiment, in a non-cartridge based syringe, the syringe comprises a syringe body at one end of which is a mounting for a needle and at the other a bung forming a chamber therebetween into which fluid may be drawn and subsequently delivered by displacing the bung towards the needle end. In such an embodiment, the bung may comprise the diaphragm and the plunger rod the protrusion. Displacing the plunger rod towards the needle end of the syringe will bring the protrusion into contact with the diaphragm and passive aspiration can occur as described hereinabove. A known fault of aspiration with known devices is the pull- back method that creates an excessive vacuum that can draw up tissue into the lumen of the needle and block it, resulting in a false negative. In addition the operation is two-handed and can result in movement of the needle point between aspiration and injection, so that the aspiration can occur in an entirely different position from the actual injection making the procedure totally inaccurate. The known devices utilise high vacuum and has a pull-back volume of often 0.5ml or more. The present invention is a low vacuum system (0.02ml) that is one-handed in operation and causes no needle point movement.

This is termed Passive Aspiration and the following is a method of achieving it.

The anterior inside end of the syringe has a protrusion through which the perforator end of the needle passes.

As such the protrusion also gives extra rigidity to the needle again ensuring the right angle perforation of the cartridge diaphragm.

When initial pressure is applied by the plunger rod to the cartridge the cartridge moves forward from the rest position and the diaphragm is stretched by the protrusion.

The forward movement is controlled by the front of the cartridge reaching the stop. This distance controls the vacuum volume very accurately and ensures the very low vacuum employed and the procedure, being one-handed prevents movement of the needle point. By gently releasing the pressure the elasticity of the diaphragm moves the cartridge back, sampling the aspirant. If clear the injection takes place at the same position as the aspirant site.