GB2415910A - A moulded syringe with an integral needle - Google Patents

Abstract

The present invention relates to syringes. The syringe of the present invention is provided with a plastics material body 12b moulded around a needle 18. The syringe provides particular advantage being used for the injection of local analgesia for dentistry or surgical procedures. The syringe of the present invention is intended to be a single use, disposable syringe to help combat the problem of needle stick injury.

Description

1 "Syringe" 3 The present invention relates to syringes.

"Needle Stick Injury'' is a problem associated with 6 the use of syringes for medical purposes. It occurs 7 when the person administering treatment to a patient 8 with such a syringe is inadvertently "stuckn by the 9 needle after it has been used on the patient.

11 Such injuries can transmit infections from patient 12 to user; including HIV, Hepatitis A, Hepatitis B. 13 Hepatitis C and new variant CJD.

Some state of the art syringes are reusable, and 16 include a removable needle which fixes to the 17 syringe, usually either by a screw thread or a 18 bayonet fixing. This is particularly common with 19 "dental'' syringes which are of slim shape and use narrow glass or plastic vials of active material.

21 Although the syringes themselves are reused, the 22 needles are not and are thrown away after use into a 23 specialized disposal unit, referred to as a "sharps" 24 container or bin, for careful disposal.

26 Needle Stick Injury is often likely to occur when 27 the needle is being removed from the syringe for 28 disposal in such a sharps box.

1 Other known syringes are disposable but are not 2 adapted for use with pre-filled vials. Disposable 3 syringes in common are supplied without needles, 4 which must be attached by the user and are normally detached after use for disposal in a sharps 6 container.

8 According to the present invention there is provided 9 a syringe comprising a body and a needle, the body being moulded around the needle.

12 Preferably the needle includes a thickened portion 13 around a portion of its outer surface, more 14 preferably the thickened portion is generally cube shaped. This thickened portion aids in the securing 16 of the moulded plastics material to the needle.

18 Preferably the body is formed from a plastics 19 material. The plastics material may be ABS (Acrylonitrile-Butadiene-Styrene) or other such 21 material suitable for the moulding process.

23 Preferably the syringe further includes a chamber 24 within the body adapted to receive a vial of anaesthetic, drug or other substance for injecting 2 6 into a patient.

28 Preferably a portion of the needle projects into the 29 chamber. The portion of the needle within the chamber punctures the seal of a vial when placed 31 within said chamber, to allow the contents of the 1 vial to be injected through the needle and into a 2 patient.

4 Preferably there is also provided a plunger co operable with the body and chamber, and in use is 6 co-operable with a vial stopper of a vial.

8 Preferably the plunger is provided with a finger 9 grip at one end and at the distal end there is provided a plunger tip, the plunger tip being 11 adapted to engage with a vial stopper. In this way 12 the plunger may be used to aspirate with the syringe 13 in addition to injecting.

An embodiment of the present invention will now be 16 described, by way of example only, with reference to 17 the following drawings, in which: 19 Fig. 1 is a perspective view of a syringe according to the present invention; 22 Fig. 2 is a perspective view of an aspirating 23 plunger of the syringe of Fig. 1; Fig. 3 is a detail view of the tip of the 26 plunger of Fig. 2; 28 Fig. 4 is a perspective view of a non 29 aspirating plunger compatible with the syringe of Fig. 1; 1 Fig. 5 is a perspective view of the needle of 2 the syringe of Fig. 1; 4 Fig. 6 is a perspective view of a breech plug of the syringe of Fig. 1; 7 Fig. 7 is a detail view of a vial of 8 anaesthetic for use in the syringe of Fig. 1; 9 and 11 Fig. 8 is a perspective view in section of a 12 stopper of the vial of Fig. 7.

14 Referring to the drawings and initially to Fig.1 there is shown a syringe according to the present 16 invention referred to by the reference number 10.

18 The syringe 10 comprises a body 12, a breech plug 14 19 and a plunger 16. Integral to the body 12 and extending from one end of it is a hollow needle 18.

22 The body 12 is formed from ABS (Acrylonitrile 23 Butadiene-Styrene) resin, which is moulded to form 24 the shape. The needle 18 is moulded within the body 12 extending between a central vial-holding chamber 26 12a through the nose 12b of the body 12 to the 27 exterior of the body 12.

29 The vial-holding chamber 12a extends within the body 12 for the majority of the body's length and is 31 divided into two sections. The first section, 32 nearest the needle 18, is partially open so that in 1 use the user can easily monitor the level of a 2 substance within a vial placed in the chamber 12a.

3 For that purpose, the two legs 12d which define the 4 first section of the chamber 12a may include a graduated scale.

7 The second section is located at the opposite side 8 of the first section to the needle 18, and is a 9 simple bore through the body 12.

11 Two finger grips 20 are provided on the body 12, 12 adjacent the second section of the chamber 12a. The 13 finger grips 20 are formed as loop-shaped lugs on 14 either side of the body 12. As the finger grips 20 are formed as loops, this aids the user in keeping a 16 firm grip on the syringe 10.

18 A breech plug 14 is also provided which fits into an 19 initial portion of the second section of the chamber 12a. Detail of the breech plug 14 is shown in Fig. 21 6.

23 The breech plug 14 is also formed from Ales and 24 includes a central bore 14a running through it. The breech plug 14 has a circular cross-section portion 26 14b that fits into the initial portion of the second 27 section of the chamber 12a. The breech plug 14 also 28 has a square cross-section portion 14c. The central 29 bore 14a runs through both of these sections. In this embodiment, the body 12 and breech plug 14 have 31 co-operating locking means to lock the breech plug 32 14 securely to the body 12 when the syringe 10 is in 1 use, but permit the breech plug 14 to be removed 2 from the body 12 when necessary. The locking means 3 is provided by a simple projection 12c and L-shaped 4 slot lid, the projection 12c being provided on the body 12 with the L- shaped slot 14d being provided on 6 the square cross section portion 14c. It will be 7 understood that the locking means may be omitted 8 without departing from the scope of the present 9 invention.

11 An aspirating plunger 16 is also provided, detail of 12 which is shown in Fig. 2. The aspirating plunger 16 13 comprises a central stem 16a with a finger grip 16b 14 provided at one end of the stem 16a. The finger grip 16b is also formed as a loop.

17 At the other end of the stem 16a from the finger 18 grip 16b there is provided a vial-engaging tip 16c, 19 shown in greater detail in Fig. 3.

21 The vial-engaging tip 16c is formed from three 22 sections. The first section 16d is frusto-conical 23 in shape, and tapers from the diameter of the stem 24 16a to a lesser diameter. The second section 16e follows on from the first section 16d and is a short 26 cylindrical section which leads to the third section 27 16f, a flange of greater diameter than the second 28 section 16e but of lesser diameter than the stem 29 16a.

31 A non-aspirating plunger 116 is shown in Fig. 4, 32 compatible with the syringe 10. This non-aspirating 1 plunger 116 differs from the plunger 16 in that 2 there is no vial-engaging tip 16c.

4 Referring to Fig. 5 there is shown detail of the hollow needle 18. The hollow needle 18 includes a 6 long needle section 18a, a short needle section 18b 7 and a cube section 18c.

9 When the needle 18 is moulded within the body 12, the long needle section 18a projects out from the 11 body 12 for insertion into a patient. The short 12 needle section 18b projects into the vial-holding 13 chamber 12a. The cube section 18c is located within 14 the nose 12b of the body 12. The shape of the cube section 18c assists the fixing of the needle 18 in 16 place within the body 12 and impedes movement of the 17 needle 18 within the moulded body 12.

19 In use, the user removes the breech plug 14 by twisting it so that the projection 12c is disengaged 21 from the L-shaped slot lid. The breech plug 14 can 22 then be removed from the body 12 along with the 23 plunger 16.

A vial 28 is inserted into the vial-holding chamber 26 12a. The sealed lid end (not shown) of the vial 28 27 is inserted first and is pushed through into the 28 chamber 12a. The breech plug 14 is reattached to 29 the body 12 and locked into place. The dimensions of the breech plug 14 and the action of reattaching 31 forces the short needle section 18b to penetrate the 32 sealed lid of the vial 28.

2 A plunger 16 or 116 can be fed through the breech 3 plug 14 to engage a vial stopper 30 (see Figs. 7 and 4 8). The vial stopper 30 depicted in Figs. 7 and 8 has a conical bore 32 within it. Detail of the 6 conical bore 32 can be seen in Fig. 8.

8 With the aspirating plunger 16, the plunger tip 16c 9 is inserted into the conical bore 32. The flange 16f is slightly wider than the initial section of 11 the conical bore 32, but since the vial stopper 30 12 is formed from a resilient material, the user can 13 force the flange 16f into the conical bore 32. Once 14 the plunger tip 16c is engaged with the vial plunger 30, the user is then able to inject by forcing the 16 vial plunger 30 toward the nose 12b of the body 12 17 or can aspirate by pulling the vial plunger 30 away 18 from the nose 12b. The ability to aspirate as well 19 as inject allows the user to ensure that the long needle section 18a is correctly placed within the 21 patient. If, for example, the syringe 10 is being 22 used to inject a local anaesthetic into a patient it 23 can be dangerous to inject a local anaesthetic into 24 a blood vessel as this can cause bradycardia, slowing of the heart rate.

27 For situations where the ability to aspirate is not 28 needed, a non-aspirating plunger 116 can be used 29 instead of a plunger 16. The non-aspirating plunger 116 does not engage the vial stopper 30, but simply 31 pushes against it, forcing it toward the needle 18 32 in use. Drawing the non-aspirating plunger 116 out 1 of the vial chamber 12a does not aspirate, since the 2 non-aspirating plunger 116 does not draw the vial 3 stopper 30 back along the vial 28 from the needle 4 18.

6 Since the syringe 10 is made from a relatively 7 inexpensive material, the present invention finds 8 particular advantage as a single use or single 9 patient (i.e. used several times but only with the one patient) device. After use, the entire syringe 11 10 can be disposed of without the user having to 12 remove the needle 18 from the body 12.

14 The embodiment of present invention described herein also provides particular advantage when used for the 16 injection of local analgesia for dentistry or 17 cervical procedures, such as LLETZ (Large Loop 18 Excision of the Transformation Zone), cold 19 coagulation, etc. particularly due to its relatively slim profile (the body is approximately lOmm in 21 diameter).

23 In prior art metal syringes where the syringe body 24 is reprocessed after use, there is a tendency for the syringe to wear and slightly deform. In 26 syringes that have been used many times, this can 27 lead to a vial breaking within the vial chamber 28 because of misalignment between plunger and body.

29 The relatively short lifetime of the present invention mitigates this tendency.

1 Modifications are envisaged to the present invention 2 which do not depart from its scope. In addition to 3 the graduated scale on the legs 12d, a collar made 4 of rubber, foam or other suitable material may be provided in the vial chamber 12a to help locate the 6 vial within the vial chamber.

8 It is to be understood that the present invention is 9 not limited to the embodiment described herein, but may be further modified in both construction and 11 detail.

Claims (1)

1 Claims 3 1. A syringe comprising a body and a needle, the 4 body being

moulded around the needle.

6 2. A syringe according to Claim 1 wherein the 7 needle includes a thickened portion around a portion 8 of its outer surface.

3. A syringe according to Claim 2 wherein the 11 thickened portion is generally cube-shaped 13 4. A syringe according to any preceding claim 14 wherein the body is formed from a plastics material.

16 5. A syringe according to any preceding claim 17 further including a chamber within the body adapted 18 to receive a vial of anaesthetic, drug or other 19 substance for injecting into a patient.

21 6. A syringe according to any preceding claim 22 wherein a portion of the needle projects into the 2 3 chamber.

7. A syringe according to any proceeding claim 26 wherein there is also provided a plunger co-operable 27 with the body and chamber, and in use is co-operable 28 with a vial stopper of a vial.

8. A syringe according to claim 7 wherein the 31 plunger is provided with a finger grip at one end 32 and at the distal end there is provided a plunger 1 tip, the plunger tip being adapted to engage with a 2 vial stopper.

4 9. A syringe substantially as hereinbefore described with reference to the accompanying 6 drawings.