GB2294855A

GB2294855A - Needle destroyer

Info

Publication number: GB2294855A
Application number: GB9418740A
Authority: GB
Inventors: Philippe Zanado; Regis Bouzigon
Original assignee: ADVANCED MEDICAL Ltd
Current assignee: ADVANCED MEDICAL Ltd
Priority date: 1994-09-16
Filing date: 1994-09-16
Publication date: 1996-05-08
Anticipated expiration: 2014-09-16
Also published as: GB2294622A; GB2294855B; GB2295302A; GB2295302B; GB9418740D0; WO1996008282A1; GB9526340D0; AU3479795A; GB2294622B; GB9526341D0

Abstract

To destroy a needle 40, a current is first passed longitudinally through the needle as the needle is pressed between electrode portions 21c, 22a of electrode assembly 20, the needle progressively melting to leave just a stub which is then destroyed by passing a current transversely between electrode portions 21b, 22c. Waste material may be arranged to fall into a compartment 8, a gate 25 to which is opened when power is supplied to the electrodes. The needle destroyer may be powered by rechargeable batteries housed in a main body to which a cassette containing the electrodes and the waste compartment may be removably fitted. <IMAGE>

Description

ELECTRICAL NEEDLE DESTROYER AND AN ELECTRODE STRUCTURE FOR DESTROYING NEEDLES DESCRIPTION The present invention relates to the electrical destruction of syringe needles.

Many devices have been proposed for destroying syringe needles by passing an electric current through them. Some of these devices, such as that disclosed in FR-A-2686516, have fixed closely spaced electrode which enable current to be passed through the distal region of a needle and thereby progressively melt it from the tip to the hub. DE-A-4103562 discloses a device where the electrodes are initially more widely spaced. However, as the needle destruction process reaches its end, one of the electrodes is pushed towards the other. Again with this device current is passed longitudinally through a needle as it is progressively destroyed.

A disadvantage suffered by both of these devices is that the needle is not completely destroyed and a small stub of needle always remains protruding from the needle hub. This stub can be sharp and present a risk of injury.

It is an aim of the present invention to overcome this problem.

It has been discovered by the present inventors that the undesirable stub can be destroyed by passing a current transversely through it.

According to a first aspect of the present invention, there is provided an electrode structure for electrically destroying a syringe needle, comprising a first station and a second station, wherein the first station comprises first and second electrode portions arranged for passing a current longitudinally through at least a distal portion of a syringe needle and the second station comprises third and fourth electrode portions arranged for passing a current transversely through at least a portion of a needle.

Preferably, the first and third electrode portions are portions of the same element. Similarly, the second and fourth electrode portions are portions of the same element.

Preferably, the second station comprises a slot. This means that the stub can be destroyed by the user performing a convenient swiping action.

According to a second aspect of the present invention, there is provided a method of electrically destroying a syringe needle comprising the steps of: passing a current, sufficient to melt a needle, longitudinally through a needle until a stub remains; and passing a current, sufficient to melt a needle, transversely through the stub.

The present invention also extends to an electrical needle destroyer including an electrode structure according to the first aspect of the present invention.

Preferably, such an electrical needle destroyer includes cover means slidingly mounted over the electrode structure, the cover having an aperture through which a needle can be applied to the electrode structure, wherein the cover means is slidable from a start position at which the aperture is over the first station, through an intermediate position at which the aperture is over the second station to a stop position. More preferably, it includes means to prevent the cover means sliding from the start position until the needle destruction process at the first station is complete. This may be achieved by providing a T-shaped opening through a wall of the destroyer over the electrodes and by a middle portion of the cover being stepped. Initially, the stepped portion will protrude through the wide portion of the Tshaped opening. In this condition the cover cannot be slid.

However, when the cover is pressed towards the electrode, only the narrower part of the stepped portion will protrude into the T-shaped opening. Since the narrower part is narrower than the leg portion of the T-shaped opening, the cover can be slid. The cover also serves to hide sparks during needle destruction.

Conveniently, the cover means includes an apertured portion containing said aperture and spring means biasing the apertured portion away from the electrode structure. This biasing is particularly beneficial when the means to prevent the cover sliding and acts to prevent the cover sliding other than when a stub is to be destroyed.

Another problem suffered by prior art electrical needle destroyers is that the electrodes wear out with time and when this happens the whole unit must be replaced.

Furthermore, some form a receptacle must be provided to collect needle waste. Usually, these receptacles comprise open-topped drawers. It is desirable that any waste receptacle be closed when removed from a needle destroyer.

It is also an aim of the present invention to overcome these problems.

According to a third aspect of the present invention, there is provided an electrical needle destroyer comprising a main body containing power supply circuitry and a cassette removably attachable to the main body, wherein the cassette contains needle destroying electrodes and a waste compartment for receiving needle waste.

Preferably, the waste compartment is provided with a gate and the main body is provided with a control for energizing the electrode assembly and a mechanical linkage, whereby operation of the control to energize the electrode assembly causes said gate to open to allow needle waste to enter the waste compartment. The linkage between the control and the gate means that the compartment is only open during needle destruction. Preferably, the gate is hinged. However, a sliding gate could be used.

According to a fourth aspect of the present invention, there is provided a needle destroying system comprising a plurality of electrical needle destroyers, each containing a rechargeable battery and having contacts for supplying charging current to the battery, and a charging unit having means to receive said plurality of said electrical needle destroyers simultaneously and contacts arranged to cooperate with the contacts on the electrical needle destroyers for charging of the batteries therein.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a hand held needle destroyer according to the present invention; Figure 2 shows the needle destroyer of Figure 1 with the cassette separated from the main body of the unit; Figure 3 is a sectional view of the cassette of Figure 2 at the start of the needle destroying process; Figure 4 is a sectional view of the cassette of Figure 2 towards the end of the needle destroying process; Figure 5a shows the cassette of Figure 1 and the button of the housing with the housing cut away for clarity; Figure 5b shows the cassette as in Figure 5a but with the button depressed; Figure 6a shows the electrode assembly of the needle destroyer of Figure 1; ; Figure 6b is a plan view of the electrode assembly of Figure 3a; Figure 7 is a schematic diagram of the electrical circuit of the needle destroyer of Figure 1; Figure 8 shows the hub of a needle and the needle stub left after the first stage of needle destruction; Figure 9 shows the hub of a needle after the second stage of needle destruction; and Figure 10 shows a multi-unit charger for needle destroyers as shown in Figure 1.

A needle destroyer according to the present invention will now be described. In the following description, terms such as top, bottom, front, back, left and right relate to the needle destroyer in the orientation shown in Figure 1.

Referring to Figures 1 to 4, a needle destroyer comprises a generally box-like housing 1 and a cassette 2 which is slidingly received in a cut away portion 3 of the housing 1.

The cut away portion 3 receives the cassette 2 such that a face of the cassette 2 forms substantially all of the front face of the needle destroyer.

The housing 1 contains a rechargeable battery pack (not shown). Contacts (not shown) are provided on the base 4 of the housing 1 so that a charging current can be applied to the battery pack. A thumb-operable button 5 is provided on the lefthand side face of the housing 1. The button 5 is coupled to control the supply of power from the battery pack.

First and second contacts 6,7 are provided on the back wall of the cut away portion 3. The first contacts 6 are connected via switching circuitry to the positive terminal of the battery pack and the second contacts 7 are connected to the negative terminal of the battery pack.

The cassette 2 contains an electrode assembly 20 at an upper location and a compartment 8 for receiving needle waste at a lower location. A T-shaped aperture 9 is provided in the front face of the cassette 2 in alignment with the electrode assembly 20. First and second vertical walls 13,14 project inwardly from the left and right side walls of the cassette.

The vertical walls 13,14 extend from the top of the cassette 2 to a point immediately above the compartment 8 and define a slot 15 between the T-shaped aperture 9 and the electrode assembly 20.

A sliding cover 10 is mounted immediately behind the aperture 9. The sliding cover 10 comprises a stepped collar 11, centrally mounted to a leaf spring 16 and which projects through the T-shaped aperture 9. A tapered hole 12 is provided through the collar 11 to enable a needle to be applied to the electrode assembly 20. The free ends of the leaf spring 16 slidingly contact the vertical walls 13,14 at their margins on either side of the slot 15. The leaf spring 16 biases the sliding cover 10 towards the front of the cassette 2.

The collar 11 has a rear portion which is shaped to conform to the shape of the bar portion of the T-shaped aperture 9.

The stepping of the collar 11 is such that a front portion thereof is narrower than the rear portion. The width of the front portion of the collar 11 is slightly less than the width of the leg portion of the T-shaped slot.

A wall 17 extends inwardly from the front wall of the cassette 2, following a rectangular path about the aperture 9.

Contacts (not shown) are provided on the back face of the cassette 2 for cooperation with the first and second contacts 6,7 on the housing 1. The contacts on the cassette 2 are coupled to respective electrodes of the electrode assembly 20. Thus, when the cassette 2 is in position and the button 5 is depressed, a voltage is applied across the electrodes of the electrode assembly 20.

A pivotable gate 25 is mounted below the electrode assembly 20 to provide access to the needle waste compartment 8 for needle waste from the electrode assembly 20.

Referring particularly to Figure 4, the collar 11 is shaped such that, when the sliding cover 10 is fully depressed, the distal end of the hub 41 of a needle 40 being destroyed can abut the electrode assembly 20.

Referring also to Figures 5a and 5b, the button 5 has a downwardly depending finger 30. The finger 30 abuts a lever 31 connected to the gate 25 of the needle waste compartment 8. When the button 5 is depressed, the finger 30 presses against the lever 31, causing it to pivot against a return spring (not shown) and thereby open the gate 25 of the needle compartment 8.

The electrode assembly will now be described in detail with reference to Figures 6a and 6b.

The electrode assembly 20 comprises a positive electrode 21 and a negative electrode 22. The positive electrode 21 has a rectangular back portion 21a, a rectangular wall portion 21b extending perpendicularly from the full length of one edge of the back portion 21a and an L-shaped front portion 21c extending parallel to and away from the back portion 21a. The negative electrode 22 comprises an L-shaped back portion 22a, lying in the same plane as the back portion 21a of the positive electrode 21, a rectangular wall 22b extending parallel to the wall 21b of the positive electrode 21 from an inner edge of the back portion 22a, and a generally rectangular front portion 22c extending from an edge of the wall portion 2b in the plane of the front portion 21c of the positive electrode 21.The electrodes 21,22 are arranged such that a needle can be placed against the internal angle 21d of the front portion 21c of the positive electrode 21 with its tip touching the back portion 22a of the negative electrode 22 whilst being parallel to the wall portions 21b,22b. This forms a first station.

Furthermore, the front portions 21c,22c are arranged such that a slot 23 is formed, running parallel to the wall portions 21b,22b. A corner of the front portion 22c of the negative electrode 22 is cut away to increase the width of the entrance to the slot 23. The slot 23 forms a second station.

Referring to Figure 7, the positive terminal of a nickelcadmium battery 50 is coupled to a first charging contact 56 and to the positive electrode 21 of the electrode assembly 20. The negative terminal of the battery 50 is coupled to a second charging contact 57 and to the source of a power MOSFET device 51. A switch 52, operatively coupled to the button 5 (see Figure 1), is connected in series with a thermal switch 53 between the negative terminal of the battery 50 and the gate of the MOSFET 51. The drain of the MOSFET 51 is coupled to the negative electrode 22 of the electrode assembly 20.

The thermal switch 53 acts to protect thee electrodes 21, 22 and prolong their lives.

The operation of the needle destroyer shown in the accompanying drawings will now be described.

Assuming that the battery pack is fully charged and a cassette 2 has been inserted into the housing 1. A user wishing to destroy a needle 40, first inserts the distal end of the needle 40 through the collar 11 so that its tip is touching the negative electrode 22 (see Figure 3). The position of the needle 40 may need some adjustment to ensure that it also contacts the positive electrode 21.

Once the needle 40 is in position at the first station, the user depresses and holds depressed the button 5. This has the effect of opening the gate 25 of the needle waste compartment 8 and turning on the MOSFET 51 to apply power to the electrodes 21,22. When the electrodes 21,22 become live, a current begins to flow longitudinally through the end portion of the needle 40 between the electrodes 21,22.

This current is sufficient to melt the needle material through which it is conducted. The user applies an axial force to the needle 40 towards the electrode assembly 20 and the needle 40 is progressively melted.

Eventually, the hub 41 of the needle 40 will be received by the collar 11. From this point on, further pressure along the needle 40, causes the collar 11 to move towards the electrode assembly 20 against the leaf spring 16. The collar 11 moves back until the needle's hub 41 contacts the electrode assembly 20 (see Figure 4).

At this stage, the needle 40 is substantially destroyed.

However, a small stub 42 (see Figure 8), slightly shorter than the spacing between the electrodes 21,22 of the electrode assembly 20 at the first station, remains.

With the leaf spring 16 fully compressed, the rear portion of the collar 11 is behind the aperture 9 and the sliding cover 10 can be slid downward, guided by the front portion of the collar 11 projecting into the leg portion of the Tshaped slot 9. Maintaining pressure against the spring, the user removes the stub 42 by swiping the syringe downwards so that the stub 42 passes along the slot 23 in the electrode assembly 20. As the stub 42 passes along the slot 23 a current flows transversely through it, melting it. The result is that no needle material extends beyond the hub 41 (see Figure 9).

The button 5 can now be released and the sliding cover 10 returned to its original position by a return spring (not shown).

Individual chargers may be provided for needle destroyers according to the present invention. Alternatively, a multiunit charger may be used to charge a plurality of destroyer.

Referring to Figure 10, a multi-unit charger 50 has a plurality of sockets 51 for receiving needle destroyers as described above. The sockets 51 contain contacts for mating with the charging contacts on the needle destroyers.

It is envisaged that the multi-unit charger 50 would be placed at a location accessible to medical staff, for example a nurses' station, and that staff would take a needle destroyer at the start of a shift and replace it at the end of the shift for recharging.

The electrode assembly of the present invention has been described with reference to a handheld needle destroyer.

However, the advantages of an electrode assembly according to the present invention may be gained also by employing it in desk-mounted or other portable electric needle destroyers.

A cassette according to the present invention and containing electrodes and a waste compartment can also be applied to desk-mounted or other portable electric needle destroyers.

In the foregoing description polarities have been assigned to the electrodes. However, the polarities of the electrodes is a matter of choice. Indeed, the present invention can be embodied using an ac power supply to the electrodes.

Claims

1. An electrode structure for electrically destroying a syringe needle comprising a first station and a second station, wherein the first station comprises first and second electrode portions arranged for passing a current longitudinally through at least a distal portion of a syringe needle and the second station comprises third and fourth electrode portions arranged for passing a current transversely through at least a portion of a needle.

2. An electrode structure according to claim 1, wherein the first and third electrode portions are portions of the same element.

3. An electrode structure according to claim 1 or 2, wherein the second and fourth electrode portions are portions of the same element.

4. An electrode structure according to claim 1, 2 or 3, wherein the second station comprises a slot.

5. An electrical needle destroyer including an electrode structure according to any preceding claim.

6. An electrical needle destroyer according to claim 5, including cover means slidingly mounted over the electrode structure, the cover having an aperture through which a needle can be applied to the electrode structure, wherein the cover means is slidable from a start position at which the aperture is over the first station, through an intermediate position at which the aperture is over the second station to a stop position.

7. An electrical needle destroyer according to claim 6, including means to prevent the cover means sliding from the start position until the needle destruction process at the first station is effectively complete.

8. An electrical needle destroyer according to claim 6 or 7, wherein the cover means includes an apertured portion containing said aperture and spring means biasing the apertured portion away from the electrode structure.

9. An electrical needle destroyer comprising a main body containing power supply circuitry and a cassette removably attacable to the main body, wherein the cassette contains needle destroying electrodes and a waste compartment for receiving needle waste.

10. An electrical needle destroyer according to claim 9 and any one of claims 5 to 8.

11. A electrical needle destroyer according to claim 9 or 10, wherein the waste compartment is provided with a gate and the main body is provided with a control for energizing the electrode assembly and a mechanical linkage, whereby operation of the control to energize the electrode assembly causes said gate to open to allow needle waste to enter the waste compartment.

12. A method of electrically destroying a syringe needle comprising the steps of: passing a current, sufficient to melt a needle, longitudinally through a needle until a stub remains; and passing a current, sufficient to melt a needle, transversly through the stub.

13. A needle destroying system comprising a plurality of electrical needle destroyers, each containing a rechargeable battery and having contacts for supplying charging current to the battery, and a charging unit having means to receive said plurality of said electrical needle destroyers simultaneously and contacts arranged to cooperate with the contacts on the electrical needle destroyers for charging of the batteries therein.

14. An electrode arrangement substantially as hereinbefore described with reference to Figures 6a and 6b of the accompanying drawings.

15. A method of destroying a syringe needle substantially as hereinbefore described.

15. An electrical needle destroyer substantially as hereinbefore described with reference to the accompanying drawings.

16. A method of destroying a syringe needle substantially as hereinbefore described.

17. A needle destroying system substantially as herein before described with reference to Figure 9 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. An electrode arrangement for electrically destroying a syringe needle comprising discrete first and second stations, wherein the first station comprises first and second electrode portions arranged for passing a current longitudinally through at least a distal portion of a syringe needle whereby the needle can be reduced to a stub, and the second station comprises third and fourth electrode portions arranged for passing a current transversely through the needle stub so as to destroy it.

2. An electrode arrangement according to claim 1, wherein the first and third electrode portions are portions of the same element.

3. An electrode arrangement according to claim 1 or 2, wherein the second and fourth electrode portions are portions of the same element.

4. An electrode arrangement according to claim 1, 2 or 3, wherein the second station comprises a slot.

5. An electrical needle destroyer including an electrode arrangement according to any preceding claim.

6. An electrical needle destroyer according to claim 5, including cover means slidingly mounted over the electrode arrangement, the cover having an aperture through which a needle can be applied to the electrode arrangement, wherein the cover means is slidable from a start position at which the aperture is over the first station, through an intermediate position at which the aperture is over the second station to a stop position.

8. An electrical needle destroyer according to claim 6 or 7, wherein the cover means includes an apertured portion containing said aperture and spring means biasing the apertured portion away from the electrode arrangement.

9. An electrical needle destroyer according to any one of claims 5 to 8, including a removably attachable cassette, wherein the cassette contains the needle destroying arrangement and a waste compartment for receiving needle waste.

11. A electrical needle destroyer according to claim 9 or 10, wherein the waste compartment is provided with a gate and the main body is provided with a control for energizing the electrode portions and a mechanical linkage, whereby operation of the control to energize the electrode portions causes said gate to open to allow needle waste to enter the waste compartment.

12. A method of electrically destroying a syringe needle comprising the steps of: passing a current longitudinally through a needle until a stub remains at a first station, the current being sufficient to melt the needle; and passing a current, sufficient to melt the stub, transversly through the stub at a discrete second station so as to destroy it.

13. An electrode arrangement substantially as hereinbefore described with reference to Figures 6a and 6b of the accompanying drawings.

14. An electrical needle destroyer substantially as hereinbefore described with reference to the accompanying drawings.