GB2216801A

GB2216801A - Syringe system

Info

Publication number: GB2216801A
Application number: GB8808242A
Authority: GB
Inventors: Malcolm Melville Davies
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-04-08
Filing date: 1988-04-08
Publication date: 1989-10-18
Also published as: GB8808242D0

Abstract

A syringe system comprises a cartridge (3) and a syringe, the cartridge (3) being located within a body portion (1) of the syringe and a syringe plunger (4) being releasably attached to a movable closure member of the cartridge (3). The closure member is movable within the cartridge (3) to inject or withdraw a substance and is so shaped that the plunger (4) of the syringe can be releasably attached thereto. <IMAGE>

Description

SYRINGE SYSTE:4 The present invention relates to a syringe system and, more especially, to a disposable syringe system for medical use although the invention is also applicable to syringe systems for non-medical (e.g. veterinary or laboratory) use.

When using a conventional medical syringe, there are a number of steps that must be carried out before the syringe is ready for use. First, the syringe and a needle must be removed from their respective sterile containers and fitted together. The glass ampoule containing the medicament to be injected is then opened and the contents withdrawn into the syringe. The needle, being no longer completely sterile, should then be replaced by another.

The time taken to carry out those steps can be significant, particularly during an emergency and it is clearly desirable that the procedure for making a syringe ready for use should be as straight forward and as quick to carry out as possible.

The procedure described above also has the disadvantage that the person administering the injection may be cut by broken glass while opening the ampoule, placing that person or the patient at risk from bacterial or viral infection.

It is an object of the present invention to enable this risk of infection to be removed and to enable the procedure for preparing a syringe for use to be simplified.

The present invention provides a cartridge for use in a syringe system to contain a substance to be injected by, or aspirated by, the syringe, the cartridge having a closure member which is movable within the cartridge to inject or withdraw the substance and which is so shaped that the plunger of a syringe can be releasably-attached thereto.

Part at least of the cartridge may be so formed that it can be punctured by a syringe needle. That part of the cartridge may, for example, be in the form of a membrane, preferably a self-sealing membrane. In an embodiment of the invention described herein, the cartridge comprises an open-ended casing one end of which is closed by a membrane and the other end of which is closed by the closure member.

The closure member may have an opening into which the end of a syringe plunger can be inserted and which is so shaped that rotation of the plunger releasablyattaches the plunger to the closure member. The opening may be in the form of a slot leading to a circular cavity in which the end of the plunger can rotate.

The present invention further provides a syringe including a body portion shaped to receive a cartridge for containing a substance to be injected by, or aspirated by, the syringe, the syringe having a plunger which is operable to inject or withdraw the substance and which is so shaped that it can be releasablyattached to the cartridge.

The body portion may have an opening through which the cartridge can be inserted into and removed from the body portion. An additional opening may be provided to facilitate removal of the cartridge through the main opening.

The plunger may have a head portion which is shaped for releasable attachment to a closure member of the cartridge. In an embodiment of the invention describe herein, the head is of elongated form for insertion in a slot in the closure member and subsequent rotation to attach the plunger releasably to the closure member.

However, other arrangements for attaching the plunger to the closure member can be used.

The body portion of the syringe has an opening through which a substance is injected or aspirated by the syringe. That opening may be shaped to receive a needle in communication with the interior of the body portion. The needle may be double ended, one end being located in the interior of the body portion. In an embodiment of the invention, that end of the needle punctures a cartridge within the body portion.

The invention further provides a syringe system comprising, in combination, a syringe and a cartridge as defined above, the cartridge being located within the body portion of the syringe and the syringe plunger being releasably attached to the movable closure member of the cartridge. A double-ended needle may be attached to the syringe, one end of the needle passing into the cartridge and the other end being available to inject a substance from, or aspirate a substance into, the syringe.

A method of assembling this combination comprises the steps of placing a cartridge in the syringe body, releasably attaching the plunger to the closure member of the cartridge and attaching a double-ended needle to the syringe body so that one end of the needle punctures and enters the cartridge.

By way of example, a syringe constructed in accordance with the invention, and a cartridge for use with the syringe, will be described with reference to the accompanying drawings, in which: Fig. 1 is a longitudinal cross-section of the syringe, also showing a side view of a needle to be fitted to the syringe; Fig. 2 is an end view of the plunger of the syringe, in the direction of the arrow II in Fig. 1; Fig. 3 is a longitudinal cross-section of the cartridge, and Fig. 4 is a end view of the cartridge, in the direction of the arrow IV in Fig. 3.

The syringe shown in Fig. 1 has a cylindrical body 1 with an opening 2 through which the cartridge 3 shown in Figs 3 and 4 can be inserted in the body. At one end, the body 1 is open to receive one end of a cylindrical plunger 4 which slides inside a sleeve 5 extending between the open end of the body and the opening 2. The plunger extends out of the syringe body 1 and at the far end, has the customary thumb pad 4a.

A flange 6 is formed around the open end of the body to enable the syringe to be held when in use.

At the other end, the syringe body 1 has an end wall 7 with an upstanding externally-threaded projection 8 having an internal bore 9 which communicates with the interior of the body.

The needle 10 that is used with the syringe is also shown in Fig. 1. The needle is double-ended (that is, it has points 11, 12 at both ends) and has a body 13 located about a quarter of the way along its length from the end 11. The body 13 is internally threaded so that it can be screwed onto the projection 8 on the syringe with the shorter length of the needle extending through the bore 9 and the end 11 of the needle located within the syringe body 1.

A medicament to be administered by the syringe is contained in the cartridge 3 shown in Figs. 3 and 4.

The cartridge 3 comprises a cylindrical open-ended casing 15 with a diameter such that it will fit within the body 1 of the syringe, the length of the cartridge 3 being such that it can be inserted into the syringe casing through the opening 2. One end of the cartridge body 15 is covered by a self-sealing polymeric membrane 16 and the other end is closed by a stopper 17 which, as described below, acts not only as seal but also as a piston: to this end, the stopper 17 has circumferential ribs 18, or a similar arrangement, by which the stopper is sealed against, but is in sliding engagement with, the internal wall of the cartridge casing 15. On the outward-facing side of the stopper 17 is an upstanding peripheral wall 19 leading to an end wall 20 which, when the cartridge is un-used, is located adjacent the end of the cartridge casing 15 as shown in Fig. 3. A diametric slot 21 cuts across the end wall 20 and into the peripheral wall 19.

The end of the plunger 4 within the syringe body has an upstanding circular stem 23 with a head 22 which, as shown in Fig. 2, is of elongated form and extends diametrically across the plunger. The width and length of the head 22 are such that the head can be inserted in the slot 21 in the cartridge stopper 17 and then rotated so that the ends of the head engage underneath the end wall 20 of the stopper to releasably attach the plunger to the stopper, in the manner of a bayonet attachment.

The manner in which the syringe is prepared for use will now be described. Initially, the syringe body 1, including the plunger 4, is enclosed in a sterile container (for example, a rigid plastic container or a paper or foil wrapping) which is ideally but not necessarily sterile. The needle 10 is enclosed in a separate sterile container, with both ends of the needle protected by respective plastics covers. The cartridge 13 containing the medicament to be administered is also enclosed in a sterile container.

The syringe body 1 is removed from its container and the plunger 4 is withdrawn to the position shown in Fig. 1. The cartridge 3 is removed from its sterile container and is inserted through the opening 2 into the syringe body with the stopper 17 facing the end of the plunger 4 and the membrane 16 facing the end of the bore 9 in the projection 8. The needle 10 is now removed from its sterile container and the protective cover is removed from the end 11 which is inserted into the bore 9 in the projection 8 so that the needle body 13 can be screwed onto the projection. As this is being done, the end 11 of the needle punctures the membrane 16 of the cartridge and comes into contact with the medicament within the cartridge.The plunger 4 is now pushed back into the syringe body until the plunger head 22 comes up against the end of the cartridge, whereupon the head 22 is inserted into the slot 21 in the cartridge stopper and rotated to attach the plunger to the stopper as already described. The syringe is now ready for use, it being necessary only to remove the cover from the end 12 of the needle. Pressure on the plunger 4 causes the cartridge stopper 17 to slide into the cartridge displacing the medicament through the needle 10.

Because the stopper 17 is attached to the plunger 4 it can be drawn back, as required, simply by withdrawing the plunger from the syringe body. This enables the syringe to be used also for aspiration, either into a previously full cartridge following an injection or into a sterile empty cartridge inserted in the syringe specifically for this purpose. The cartridge can then be removed from the syringe and sent directly to a laboratory for analysis of the contents, eliminating the need to transfer the aspirate to a separate container for dispatch to the laboratory as at present.

Alternatively, when one cartridge has been used, another cartridge can be inserted in the syringe if required without withdrawing the needle from the patient. To do this, the plunger 4 is rotated and uncoupled from the cartridge stopper 17 and is then withdrawn, whereupon the cartridge can be removed and replaced by another.

The procedure for preparing the syringe for use is straightforward and can be carried out speedily even under difficult conditions, such as might be encountered in an emergency situation, without risk of infection either to the operator or to the patient. A syringe having the form described can be used for any of the main types of injection (for example, subcutaneous, intramuscular, intravenous and intra-articular injections) and a range of syringes of different sizes can be provided, each size being intended for use with a respective size of cartridge.

The syringe body 1 and plunger 4 can be formed from any suitable polymeric material, for example, polypropylene, polystyrene or polycarbonate. The materials from which the cartridge body 15, the membrane 16 and stopper 17 are formed must be selected having regard to the medicament that the cartridge is to contain, to ensure that there is no reaction with the medicament and that the latter has an adequate shelf life. For certain medicaments, plastics materials can be used for the body 15 and stopper 17 provided that the stopper will slide easily within the cartridge body when the medicament is being administered.

The self-sealing membrane 16 can be of any suitable material that will be readily punctured by the end 11 of the needle 10.

If required, a thumb hole (not shown) can be provided in the syringe body 1 diametrically opposite the opening 2 to enable a cartridge to be pushed out of the syringe after use.

Other arrangements for attaching the plunger 4 to the cartridge stopper 17 can be used. For example, the head 22 can be located on the stopper 17 and the slot 21 in the end of the plunger 4. Alternatively, a simple screw-threaded connection or hook-and-eye connection between the plunger 4 and the stopper 17 could be used or, as a further alternative, some form of suction, or magnetic, connection. Although not essential, some form of stop arrangement, for example a lip or rim, may be provided to ensure that the stopper 17 can not be withdrawn completely from the cartridge.

Claims

Claims:

1. A cartridge for use in a syringe system to contain a substance to be injected by, or aspirated by, the syringe, the cartridge having a closure member which is movable within the cartridge to inject or withdraw the substance and which is so shaped that the plunger of a syringe can be releasably-attached thereto.

2. A cartridge as claimed in claim 1, in which part at least of the cartridge is so formed that it can be punctured by a syringe needle.

3. A cartridge as claimed in claim 2, in which the part of the cartridge that can be punctured is in the form of a membrane.

4. A cartridge as claimed in any preceding claim, in which the cartridge comprises an open-ended casing one end of which is closed by a membrane and the other end of which is closed by the closure member.

5. A cartridge as claimed in any preceding claim, in which the closure member has an opening into which the end of a syringe plunger can be inserted and which is so shaped that rotation of the plunger releasably attaches the plunger to the closure member.

6. A cartridge as claimed in claim 5, in which the opening is in the form of a slot leading to a circular cavity in which the end of the plunger can rotate.

7. A cartridge for use in a syringe system to contain a substance to be injected by, or aspirated by, the syringe, the cartridge being substantially as herein described with reference to and as illustrated by Figs. 3 and 4 of the accompanying drawings.

8. A syringe including a body portion shaped to receive a cartridge for containing a substance to be injected by, or aspirated by, the syringe, the syringe having a plunger which is operable to inject or withdraw the substance and which is so shaped that it can be releasably attached to the cartridge.

9. A syringe as claimed in claim 8, in which the body portion has an opening through which the cartridge can be inserted into and removed from the body portion.

10. A syringe as claimed in claim 9, in which an additional opening is provided in the body portion to facilitate removal of the cartridge through the main opening.

11. A syringe as claimed in any of claims 8 to 10, in which the plunger has a head portion which is shaped for releasable-attachment to a closure member of the cartridge.

12. A syringe as claimed in claim 11, in which the head portion is of elongate form for insertion in a slot in the closure member and subsequent rotation to attach the plunger releasably to the closure member.

13. A syringe as claimed in any of claims 8 to 12, in which the body portion of the syringe has an opening through which a substance is, in use, injected or aspirated by the syringe, the opening being shaped to receive a needle in communication with the interior of the body portion.

14. A syringe as claimed in claim 13, in which the needle is double-ended, one end being located in the interior of the body portion.

15. A syringe including a body portion shaped to receive a cartridge for containing a substance to be injected by, or aspirated by, the syringe, the syringe being substantially as herein described with reference to and as illustrated by Figs. 1 and 2 of the drawings.

16. A syringe system comprising, in combination, a syringe as claimed in any of claims 8 to 15 and a cartridge as claimed in any of claims 1 to 7, the cartridge being located within the body portion of the syringe and the syringe plunger being releasably attached to the movable closure member of the cartridge.

17. A syringe system as claimed in claim 16, in which a double-ended needle is attached to the syringe, one end of the needle passing into the cartridge and the other end being available to inject a substance from or aspirate a substance into the syringe.

18. A method of assembling a syringe system as claimed in claim 17, the method comprising the steps of placing a cartridge in the syringe body, releasably attaching the plunger to the closure member of the cartridge and attaching a double-ended needle to the syringe body so that one end of the needle punctures and enters the cartridge.