WO2006032064A1

WO2006032064A1 - Improved needle protective device

Info

Publication number: WO2006032064A1
Application number: PCT/ZA2005/000139
Authority: WO
Inventors: Ricardo Sheath Oxford Steyn
Original assignee: Ratio Investments Close Corporation
Priority date: 2004-09-15
Filing date: 2005-09-13
Publication date: 2006-03-23

Abstract

The invention discloses a hypodermic needle protective device which includes a slightly curved elongate tubular member (14) having disposed about its circumference at least one elongate axial cut-out (18) in a wall thereof extending over a greater portion of its length, manufactured of a resiliently flexible material, the tubular member having, at its one end, attachment means for attachment to a hub (22) of a hypodermic needle and having, at its opposite end, an end cap (16) manufactured of a hard material, the end cap having a blocking surface (36) in which is formed an opening (38) through which a point (15) of the needle can pass, in use, and a guide formation (39) for guiding the needle towards the opening in the blocking surface, in use.

Description

FIELD OF THE INVENTION

This invention relates to a needle protective device. More particularly, this invention relates to a protective device for a needle of a hypodermic syringe, catheter or the like device for use on humans or animals.

BACKGROUND TO THE INVENTION

Hypodermic needles are widely used all over the world for medical (human and veterinary) use, including, but not limited to the administration of injections, the drawing of blood, intravenous feeding etc. People who handle these needles on a daily basis, such as medical professionals and cleaning personnel are at risk of accidental needle stick injuries, i.e. the accidental piercing of the body with the point of the needle. This is obviously dangerous as the needle may be contaminated by dangerous pathogens. Even more obvious today are the dangers presented to medical and cleaning personnel who handle hypodermic needles and apparatus including hypodermic needles, in the form of Acquired Immune Deficiency Syndrome or AIDS, which can easily be transmitted to such personnel as a result of needle stick injuries.

There are many devices on the market .today which purport to alleviate these dangers in some way or another. Mostly, however, these known devices suffer from very serious disadvantages. These disadvantages include the handler having to execute a positive act to make the needle safe. For example,^' the handler may have to draw the used needle into the barrel of a specially designed hypodermic syringe and needle apparatus. With an arrangement as generally described above, the needle would not be covered if, for example, the handler accidentally drops or fumbles with the apparatus before he or she has had an opportunity to execute the procedure for making the needle safe. Moreover, some of the known safety arrangements available today require at least some training or product knowledge to operate effectively. Cleaning personnel who sometimes have to handle used hypodermic apparatus would not normally have this knowledge or training and are accordingly more at risk of being infected. 39

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided a hypodermic needle protective device which includes a slightly curved elongate tubular member having disposed about its circumference at least one elongate axial cut-out in a wall thereof extending over a greater portion of its length, manufactured of a resiliently flexible material, the tubular member having, at its one end, attachment means for attachment to a hub of a hypodermic needle and having, at its opposite end, an end cap manufactured of a hard material, the end cap having a blocking surface in which is formed an opening through which a point of the needle can pass, in use, and a guide formation for guiding the needle towards the opening in the blocking surface, in use.

It will be appreciated that in this specification and in the appended claims, the term "hard" when used in relation to "end cap", means substantially resistant to penetration by the point of a hypodermic needle.

The end cap may be manufactured of a hard plastics material. Preferably, the end cap is manufactured of a transparent, hard plastics material.

In use, the tubular member is approximately the same length as a hypodermic needle to which it is attached. Once attached, the slightly curved tubular member circumscribes the needle, which extends the length of the tubular member and the point of the needle is displaced from the center or longitudinal axis of the tubular member near its free end due to the curvature of the tubular member.

Thus, in this specification, the terms "slightly curved" or "curved" in relation to the tubular member, means curved to the extent that a straight line of substantially the same length as the tubular member, extending from the center of one end of the tubular member, terminates at a position which is off-set from the center of the tubular member at its opposite end. In use, the end cap encloses the point of the needle, which needle point is displaced from the center of the end cap due to the curvature of the tubular member. The end cap includes an opening through which the needle point extends during use and this opening is located at a side of the end cap which is opposite to the side to which the needle point is displaced. Thus, the needle point and the end cap opening are not aligned and a positive alignment action by the user is required to align the needle point and the end cap opening. This misalignment of the needle point and the end cap opening serves to prevent or minimise accidental needle stick injuries.

In one form of the invention, the tubular member includes two axial cut-outs, preferably diametrically opposed to each other.

The cut-outs may be in the form of slots or splits in the wall of the tubular member. In a preferred form of the invention, the cut-outs terminate in rounded holes.

The end cap may, in one form of the invention, include a chamber which is open at one end which is attached to one end of the tubular member, the blocking surface being sloped and located at an opposite end of the chamber.

The end cap may be provided internally with one or more guide formations for guiding a point of the needle to a mouth of the opening when the needle is displaced sideways within the end cap. The guide formations may be in the form of ridges or slots defined in the wall of the end cap.

The end cap preferably defines an open spigot formation having an outwardly extending collar, the one end of the tubular member locating over the spigot formation and bearing against the collar, in use. The collar may include one or more cut-outs to accommodate gripper elements during an assembly process to stretch the tubular member over the spigot formation. The tubular member may be made from a silicone rubber material having a Shore hardness of between 30 and 80. The tubular member may be moulded or extruded. Preferably, the tubular member is extruded.

In a preferred form of the invention, the tubular member is extruded with an uneven side wall thickness.

The uneven side wall thickness of the tubular member causes it to be extruded in a curved shape, the diameter of the curve being relative to the difference in the thickness of the side wall of the tubular member. I.e., the greater the difference in the wall thickness of the tubular member, the smaller the curvature diameter.

In an alternative form of the invention, or in addition, the tubular member may be mounted to the needle hub in a skewed manner so as to deform the tubular member slightly into a curved shape relative to the needle.

It will be appreciated that in this specification, and in the appended claims, the term "skewed", when used in relation to the tubular member, should be construed in accordance with the detailed description of the preferred embodiments, specifically with reference to Figure 1.

The tubular member may further include laterally extending fins. The fins may terminate in rounded bead formations.

The bead formations allow the gripper elements to be attached to the fins in order to stretch the tubular member over the hub of the needle and over the spigot formation of the end cap during an automated assembly process of the device.

The end cap is preferably made from a transparent material so that at least the point of the needle is visible. The end cap is preferably made by way of an injection moulding process, from a hard plastics material. Further according to the invention, the needle includes a bevel which, in use, is orientated opposite to the slope of the blocking surface. In this way, when the needle point is directed towards the opening in the blocking surface and touches the side wall of the end cap, the point does not snag against the side wall.

The needle, once the protective device has been attached thereto, may be bent slightly to remain out of alignment with the opening in the end cap. In this way, a skewed fitting of the device to the needle is obviated.

According to another aspect of the invention, there is provided a hypodermic needle having attached thereto a protective device as defined above. The hypodermic needle may be in the form of catheter or the like.

The invention further extends to a method of assembly of a hypodermic needle including a hypodermic needle protective device as defined above and to method of assembly of a hypodermic catheter device including a hypodermic needle protective device.

One embodiment of this invention will now be described in more detail with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a partly sectioned side view of a hypodermic needle fitted with a needle protective device according to the invention;

Figure 2 is a side view of the needle and device of Figure 1 , viewed from a direction 90 degrees rotated from the direction shown in Figure 1;

Figure 3 is a top view of the needle and device of Figures 1 and 2; Figure 4 is a sectioned view of the needle and device of Figures 1 and 2 along line III - Ill, showing the positions of feeder rollers during the manufacturing stage of the tubular member;

Figure 5 is a side view of the device of Figures 1 and 2 with the needle exposed and ready for use;

Figure 6 is a partly sectioned, schematic side views of a catheter arrangement fitted with a needle protective device according to the invention; and

Figure 7 is a schematic side view of the arrangement of Figure 1 with the needle of the catheter extended into the cannula.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In Figures 1 to 5, a needle protective device 10 according to the invention is shown to be fitted to a hypodermic needle 12. The device 10 includes attachment means 13, a tubular member 14 and an end cap 16 which protects the point 15 of the needle 12 during handling.

The tubular member 14 is made from medical grade silicon rubber with a Shore hardness of between 30 and 80 in an extrusion process. As is evident from Figure 1 , the member 14 is slightly curved. The curvature may be attained in various ways, but in this embodiment, an extrusion die (not shown) is used which gives the one side wall of the tubular member a slightly greater thickness than the opposite side. A slight curvature can also be attained by providing a slight bend in the extrusion die (not shown) or by way of special post curing processes or by a combination of the above.

The silicone rubber is transparent but may be colour coded to indicate needle dimensions. An advantage of using a resiliently flexible member include the fact that the member can be twisted axially and still resume its shape after release. The overall design of the device furthermore lends itself to use by a left- or right handed user.

The curvature may also be obtained by a "skewed" fitting of the member 14 to the hub 22 of the needle 12 (or to the end cap 16, for that matter). This would be accomplished by, instead of locating the end of the member 14 flush against the collar 30 as shown in Figure 1 , only a portion, or one side of the end of member 14 (the right hand side in Figure 1 for purposes of this illustration) bears up flush against the collar 30 and the other side (the left hand side) extends only to position A indicated on Figure 1.

The curvature can also be obtained during a process of "curing" after extrusion when the tubular member raw material lies rolled up for a period of time - typically ten days or so. Alternatively, the tubular member 14 can be moulded from a mouldable plastics material, and the mould defining the required slight curve.

The tubular member 14 is in the form of a slightly curved cylinder having axially extending slots 18 therein. The slots 18 terminate in rounded holes 19 to prevent the slots 18 from tearing. The tubular member 14 further includes laterally extending fins 17 which terminate in bead formations 20. The bead formations 20 provide purchase to grippers (not shown) which grip and stretch the fins 17 over a hub 22 of the needle 12 and a spigot formation 24 on the end cap 16 during assembly.

As is shown in Figure 4, during the manufacturing process of the tubular member, the member 14 is located between two feeder rollers 21. The feeder rollers 21 extend the member 14 from a roll of raw material (not shown) to a die (not shown) which cuts the slots 18. The feeder rollers 21 grip the member 14 between fins 17 as shown, and have knurled contact surfaces where the rollers 21 make contact with the member 14. 39

The end cap 16 also includes a collar 26 against which the tubular member 14 bears once attached to the end cap 16. The collar 26 includes a plurality of cut-outs 28 to provide space for the grippers (not shown) during an automated assembly process.

It will be appreciated that although the invention lends itself to automated assembly, it is nevertheless simple enough in design for hand assembly.

The needle 12 is conventional and includes a hub 22 with an end collar 30 and an elongate hollow steel shaft 32 extending from the hub 22.

The end cap 16 is made from medical grade clear polystyrene and defines an inner chamber 34, a sloped blocking surface 36 and an opening 38 in the blocking surface 36. On the inner chamber is provided a guide formation 39 (see Figures 1 and 2). The guide formation 39 defines a pair of parallel ridges 41 (see Figure 2) which extend towards the mouth of the opening 38 as shown in Figure 2. The guide formation 39 aids a user in finding the opening 38 easily and quickly when the needle point 15 is required to be advanced through the opening 38.

It will be appreciated that the end cap 16 can be made from any suitable hard plastics material, including polypropylene or polycarbonate.

The attachment means13 is defined by the lower end of the tubular member 14 and is attached to the hub 22 by way of a friction fit method, adhesive or a combination thereof.

The sloped blocking surface 36 is so shaped to facilitate the administration of an intravenous injection where the needle 12 is required to enter the patient at an angle. The shaft 32 may be bent slightly further to facilitate this type of procedure.

Along the edges of the axial slots 18 in the tubular member 14, notches 50 are provided. These notches 50 ensure that when the tubular member 14 is axially compressed it will be disposed to bow outwardly as shown in Figure 5, enabling the end cap 16 to be retracted over the shaft 32 of the needle 12 until it encounters the needle hub 22. The notches 50 require a notch shaped cutting tool during the manufacturing process and the shape of such a tool provides for a more stable cutting operation than a straight tool.

The invention allows the needle 12 to remain sterile through an entire injection procedure as it is not at any stage, before, during and after the procedure, necessary to touch the needle 12.

The end cap 16 can be used to bear against the needle 12 for purposes of bending the shaft 32 as described above. Again, this procedure allows bending the shaft 32 without the user having to touch it.

One or both fins 17 of the tubular member 14, once bowed outwardly and the end cap 16 having extended over the shaft 32, is/are held against the syringe (not shown), thus exposing the needle for an injection. Once the injection is completed, the user releases the held down tubular member 14 and its resiliently flexible nature causes it to resume its shape so that the end cap 16 again covers the needle point 15. Thus, no re-capping of the needle 26 is necessary after use.

With this arrangement, syringes can be pre filled with medication and used as and when required, without having to cap the needles after filling.

In Figure 1 , the device is shown to include a lever 25 (shown in broken lines). This lever 25 is useful in certain applications where a user may want to administer repeated injections without the end cap 16 automatically covering the needle point 15. In order to accomplish the aforegoing, the needle shaft 32 is "jammed" in opening 38 and the cap is held back by means of friction between the needle shaft 32 and the opening¹ 38. This works particularly well when the opening 38 is made very small, i.e. only just big enough for the needle to pass through straight. Once the user has administered the required repeated injections, the lever 25 is flicker forward to release the needle 32 from the opening and the end cap 16 moves over the needle point 15. In Figures 6 and 7, a needle protective device 110 according to the invention is shown to be fitted to a hypodermic needle 112. The device 110 includes an attachment means 113, a tubular member 114 and an end cap 116 which protects the point 115 of the needle 112 during handling. The arrangement further includes a cannula 117 which locates over a spigot formation 118 on the end cap 116. In this embodiment, the end cap 116 includes a flange 116.1 which is orientated at an angle "a" relative to a line perpendicular to the longitudinal axis L of the end cap 116 as shown in Figure 6. The tubular member 114 is attached to the end cap 116 so that the end of the tubular member 114 bears flush against the flange 116.1 and this causes the tubular member 114 to be curved slightly out of axial alignment with the longitudinal axis L.

The arrangement thus causes the tip 115 of the needle 112 to be off-set within the end cap 116 as shown in Figure 1.

The tubular member 114 is made from medical grade silicon rubber with a Shore hardness of between 30 and 80 in an extrusion process.

The needle 112 is conventional and includes a hub 122 with an end collar 130 and an elongate hollow steel shaft 132 extending from the hub 122.

The end cap 116 is made from medical grade clear polystyrene and defines an inner chamber 134, a sloped blocking surface 136 and an opening 138 in the blocking surface 136.

The attachment means 113 is defined by the lower end of the tubular member 114 and is attached to the hub 122 by way of a friction fit method, adhesive or a combination thereof.

In use, the needle shaft 132 and the cannula 117 are inserted into a vein (not shown) of a patient. The friction between the undersized cannula 117 and the needle shaft 132 retain the arrangement 110 in position as shown in Figure 7. Alternatively, the needle shaft 132 may be slightly bent to provide the necessary friction between itself and the cannula 117. Once the cannula 117 is properly inserted into the vein, the needle 132 is extracted from the cannula 117 and the cannula 117 is retained in place in the vein. A conventional intravenous drip arrangement (not shown) may then be attached to the cannula 117.

The invention allows the needle 112 to remain sterile through the procedure as it is not at any stage, before, during and after the procedure, necessary to touch the needle 112.

The tubular member 114, once bowed outwardly as shown in Figure 7 and the end cap 116 having extended over the shaft 132, is held firm to expose the needle 132 and the cannula 117. Once the procedure is completed, the user releases the held down tubular member 114 and its resiliently flexible nature causes to resume its shape so that the end cap 116 again covers the needle point 115. Thus, no re¬ capping of the needle 126 is necessary after use.

One of the main advantages of the invention is that it requires no positive intervention from the user to make the device safe after use. The tubular member is simply released which causes the end cap to cover the tip of the needle. In some known safety devices, the user needs to pull or push the plunger of the device until he or she hears or feels a positive "click" which is not necessary with the current invention.

It will be appreciated that many variations or modifications of the invention are possible without departing from the scope of the appended claims.

Claims

1. A hypodermic needle protective device which includes a slightly curved elongate tubular member having disposed about its circumference at least one elongate axial cut-out in a wall thereof extending over a greater portion of its length, manufactured of a resiliency flexible material, the tubular member having, at its one end, attachment means for attachment to a hub of a hypodermic needle and having, at its opposite end, an end cap manufactured of a hard material, the end cap having a blocking surface in which is formed an opening through which a point of the needle can pass, in use, and a guide formation for guiding the needle towards the opening in the blocking surface, in use.

2. A device as claimed in claim 1 wherein the tubular member features uneven side wall thicknesses and is deformed slightly as a result of the uneven wall thicknesses, into a curved shape relative to the needle, when mounted to the needle, in use.

3. A device as claimed in claims 1 or 2 wherein the tubular member is mountable to the needle hub in a skewed manner so as to deform the tubular member slightly into a curved shape relative to the needle, when mounted to the needle, in use.

4. A device as claimed in any one of claims 1 to 3 wherein the tubular member is manufactured of a silicone rubber material by way of an extrusion process.

5. A device as claimed in claim 4 wherein the tubular member has a Shore hardness of between 30 and 80.

6. A device as claimed in any one of claims 1 to 5 wherein the tubular member features two axial cut-outs, located substantially diametrically opposed to each other.

7. A device as claimed in claim 6 wherein the cut-outs are in the form of slots in the side wall of the tubular member.

8. A device as claimed in claim 7 wherein the cut-outs terminate in rounded holes.

9. A device as claimed in any one of claims 1 to 7 wherein the end cap is manufactured of a transparent, hard plastics material. 2005/000139

10. A device as claimed in claim 9 wherein the end cap includes a chamber which is open at its one end which is attached to the tubular member, the blocking surface, including the opening, being located at the opposite end of the chamber.

11. A device as claimed in claims 9 or 10 wherein the end cap defines an open spigot formation at its said one end, having an outwardly extending collar, the one end of the tubular member locating over the spigot formation and bearing against the collar, in use.

12. A device as claimed in any one of claims 9 to 11 wherein the blocking surface is sloped and orientated at an angle other than 90 degrees relative to a central axis of the end cap

13. A device as claimed in claims 11 or 12 wherein the collar includes one or more cut-outs to accommodate gripper elements during an assembly process to stretch the tubular member over the spigot formation.

14. A device as claimed in any one of claims 1 to 12 wherein the end cap is manufactured by way of an injection moulding process.

15. A device as claimed in any one of claim 1 to 14 wherein the guide formation is in the form of ridges on a wall of the end cap.

16. A device as claimed in any one of claims 1 to 14 wherein the guide formation is in the form of a groove in the wall of the end cap.

17. A device as claimed in any one of the previous claims wherein the tubular member includes laterally extending fins.

18. A device as claimed in claim 17 wherein the fins terminate in rounded bead formations.

19. A hypodermic needle including a hypodermic needle protective device as claimed in any one of claims 1 to 18.

20. A hypodermic needle as claimed in claim 19 wherein the needle includes a bevel which, in use, is orientated opposite to the slope of the blocking surface of the end cap.

21. A hypodermic catheter device including a hypodermic needle protective device as claimed in any one of claims 1 to 18. 39

22. A method of assembly of a hypodermic needle including a hypodermic protective device as claimed in any one of claims 1 to 18 including the step of fitting the tubular member to a hub of the needle in a skewed fashion.

23. A method of assembly of a hypodermic catheter device including a hypodermic protective device as claimed in any one of claims 1 to 18 including the step of fitting the tubular member to a hub of the needle in a skewed fashion.

24. A hypodermic needle protective device substantially as described herein with reference to the accompanying drawings.

25. A hypodermic needle substantially as described herein with reference to the accompanying drawings.

26. A hypodermic catheter device substantially as described herein with reference to the accompanying drawings.

27. A method of assembly of a hypodermic needle substantially as described herein with reference to the accompanying drawings.

28. A method of assembly of a hypodermic needle substantially as described herein with reference to the accompanying drawings.

DATED AT PRETORIA THIS β