GB2260707A - Hypodermic needle destruction device - Google Patents

Abstract

The device comprises a housing 1 having an aperture for access to a pair of electrical contacts adapted to make contact with a hypodermic needle at spaced positions to heat and destroy the needle between those positions as the needle is fed, roughly axially, towards the contacts. The device is battery powered and preferably completely self-contained with provision for recharging or replacing the battery. Two access apertures 3, 4 may be provided, one being formed to enable the removal of friction fit needle bases from a syringe and the other to facilitate removal of screw thread type bases such as barrel or twist noodles. <IMAGE>

Description

HYPODERMIC NEEDLE DISPOSAL DEVICE FIELD OF THE INVENTION This invention relates to a hypodermic needle disposal device which is adapted to dispose of, and render harmless, at least the zone of a hypodermic needle which actually penetrates the skin of a patient during use thereof and which may, accordingly, carry harmful germs or viruses.

BACKGROUND TO THE INVENTION There is a fear, and a real danger, that personnel working with patients who have, or may have, the HIV or Hepatitis B or Hepatitis C viruses, as well as other germs and viruses, could become infected, particularly as a result of the skin of such a person being broken by, in amongst other things, hypodermic needles which have been used to inject, infuse, or transfuse into or from a patient. The breaking of medical personnel's own skin with a used hypodermic needle is commonly referred to as a "needle-stick". It is well known that medical personnel suffer from needle sticks on a regular, although infrequent basis.

The problems associated with sterilising hypodermic needles adequately results in the use, primarily, and almost exclusively, of disposable hypodermic needles. This approach takes care of the danger to other patients but does not adequately protect medical personnel, or other persons attending to the ultimate disposal of such hypodermic needles from the danger of needle-sticks or like injuries and consequent infections.

In order to facilitate disposal of hypodermic needles in a manner in which any germs or viruses adhering to the needle are simultaneously destroyed, there has been proposed, in U S Patent Number 4628169, an electrical mains operated hypodermic needle destruction device. This device embodies a transformer which provides a low voltage AC output to a pair of contacts which are spaced apart and arranged so that a hypodermic needle can be located to short circuit the contacts which thereby become thermally destroyed by virtue of the resultant temperature generated by the current flowing through the relatively small cross-section of the needle. In fact, the zone of the hypodermic between the contacts at any time becomes thermally destroyed, often into a powder form.

Said U S Patent Number 4628169 also describes a casing having an aperture providing access to the contacts from outside. The access aperture has means for enabling a frictional fit type of needle supporting base to be removed from the relevant syringe or the like.

However, the device proposed in this prior patent suffers from certain shortcomings. Firstly, and most importantly, the fact that the device is mains operated means that it must be connected to an electrical mains outlet at the point where it is to be used. Thus, when medical personnel move around a hospital, from patient to patient, used and possibly infected needles, are nevertheless kept on a tray or trolley for destruction at a point where the destruction device is located and connected to an electrical mains power supply. Accordingly, the used needles need to be handled further after they have been used for injection purposes and this creates the same danger as existed previously albeit of a shorter duration.

Secondly, the proposed device does not adequately cater for the removal of the needle supporting base from its associated syringe in the case of a barrel syringe where the needle base is to be rotated relative to the syringe in order to release it therefrom. Applicant believes that there are other forms of needle bases which also require unscrewing from their associated syringes or other medical equipment.

It is the object of this invention to provide a hypodermic needle destruction device which is capable of being employed in a manner in which the aforesaid disadvantages are, at least to some extent, alleviated.

SUMMARY OF THE INVENTION In accordance with this invention there is provided a hypodermic needle destruction device comprising a housing, an access aperture through the wall of the housing and providing an access path for a hypodermic needle to contact a pair of electrodes within the housing, the electrodes being arranged to operatively contact a hypodermic needle introduced through said aperture at spaced positions along the length of the needle to short circuit the electrodes and thereby to destroy the needle by electrically generated heat between said spaced positions, and an electrical supply circuit for supplying electrical power to the contacts, the device being characterised in that the electrical supply circuit is adapted to supply direct current electrical power to the electrodes from an electrical battery power supply.

Further features of the invention provide for the device to be self-contained and to include an electrical battery power supply; for the electrical battery power supply to be located within the housing; for the batteries to be rechargeable in which case the electrical circuit embodies a battery charger circuit adapted for releasable connection to an external supply of electrical energy for charging the batteries; for the battery power supply to be, in the alternative, releasably attached to the device wherein the attachment embodies contacts for connecting the battery to the electrical supply circuit; for the electrical supply circuit to embody a normally open, spring loaded switch connected between the battery power supply and the electrodes; and, for the electrical power supply circuit to embody one or more displays for indicating the state of the battery power supply.

Still further features of this invention provide for the battery power supply to have a capacity of at least 2,2 ampere hours and preferably 2,5 ampere hours at a capacity of 5 hours duration; and for the battery power supply to be nickel cadmium batteries, preferably four such batteries permanently electrically connected to each other.

Additional features of the invention provide for the housing to have two access apertures, one having means for enabling a friction fit needle to be parted from a syringe, and the other having a convergent zone adapted to grip a needle base and hold it angularly to enable a syringe to be unscrewed therefrom, in which case each access aperture has a pair of electrodes associated therewith.

In order that the invention may be fully understood one embodiment thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Fig. 1 is an isometric view of one embodiment of the invention; Fig. 2 is an enlarged isometric view of one access aperture, partly broken away; Fig. 3 is a detailed sectional view taken along line III - III in Fig. 1; Fig. 4 is a plan view of the other access aperture to the housing; Fig. 5 is a detailed cross section through the latter aperture taken along line V - V in Fig. 4; Fig. 6 is a partly schematic plan view showing the interior of the device and the most important components thereof; Fig. 7 is a cross section taken along line VII VII in Fig. 6 with the casing complete; and Fig. 8 is a block type of circuit diagram of the electrical circuit of the device.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS In the embodiment of the invention illustrated in the drawings, the hypodermic needle destruction device comprises a housing, generally indicated by numeral 1 made of injection moulded plastics material.

The top face 2 of the housing has two elongate access apertures 3 and 4 therethrough each of which provides access to a pair of electrodes 5 fixed to the underside of the top 6 (see Fig. 7). In each case the one electrode 5a is inclined away from the top 6 and extends across the access of the aperture at one end thereof. The other electrode 5b is parallel to the top 6 and its end edge 7 terminates midway across the access of the aperture. Thus, as illustrated in Fig. 7, when a hypodermic needle (indicated by numeral 8) is passed through the one end of the aperture it will abut the inclined surface of the one electrode 5a and be pushed into contact with the end of the other electrode Db.

The hypodermic needle will then carry current from one electrode to the other and, with the electrodes suitably energised, the hypodermic needle will become heated to an extremely high temperature between the two positions contacted by the electrodes and will in fact be incinerated. As the hypodermic needle is thrust further against the inclined electrode 5a so the needle will continue to be incinerated until it can no longer be fed towards the electrode.

In the case of the one aperture 3, the one end 9 is provided with an inner flange forming a stop 10 for the flange 11 on the base 12 of a hypodermic needle 13 (see Figs 2 and 3) of the friction fit type. In the case of this aperture 3, the flange 11 on the base will engage the stop 10 in the aperture and thereby prevent further feeding of the hypodermic needle towards the electrodes. This stage is chosen such that any part of the hypodermic needle which would have been actually inside a patients skin will have been incinerated.

Adjacent the end 9 of the aperture 3 are a pair of inwardly directed lips 14, the undersurface 15 of which is ramped so that it increases in distance away from the face 2 of the housing with increasing distance from the end 9. Thus, as shown in Fig 3, when a syringe 16 carrying a hypodermic needle base 12 is moved along the slot-like aperture, the ramp surface 15 will enagage the flange 11 on the hypodermic needle base to cause it to be moved axially off the spigot 17 carrying the base and to fall down into a receptacle 18 in the form of a drawer. The drawer also receives any remnants of the incinerated needles which fall from the electrodes.

The other aperture 4, on the other hand, and which is elongate in shape, has two convergent, oppositely directed flanges 19 converging along its length. These flanges 19 are arranged such that, by urging a syringe carrying a screw thread type of hypodermic needle base can be urged between the converging surfaces to grip the base and thereby enable the syringe to be rotated relative thereto to release the hypodermic needle base and allow it also to fall into the receptacle 18.

In the above manner the two different methods of attachment of hypodermic needle bases to syringes is catered for.

As provided by this invention, the electrodes 5 are energised by means of a self-contained battery 20 which, in this case, comprises four 1.2 volt nickel cadmium batteries welded together with a nickel strip in series The capacity of the composite battery is 2,5 ampere hours over 5 hours. The batteries are connected to the electrodes by way of a DC fuse 21 and a normally open, spring-loaded switch 22 which must be depressed in order to energise the electrodes.

The electrical circuit of the device also embodies three light emitting diodes 23, one of which is adapted to become illuminated when the switch 22 is depressed.

The electrical circuit still further includes a battery charger circuit 24 connected by way of fuse 25 to an input plug 26 adapted to releasably receive a power lead. The battery charger circuit is connected to a second of the LED's to indicate when the battery is being charged and to a third LED to indicate when the charge in the battery is high.

In the manner described above a completely self-contained hypodermic needle destruction device is provided which can simply be charged during periods of non-use. Thereafter it may be transported, for example, on a medical persons trolley, tray or the like, and used to destroy hypodermic needles as patients are administered injections and other medication. The provision of a destruction device of this nature which is portable and which can be taken to the site at which an injection is actually given, is highly advantageous in that no handling of the hypodermic needles after use is necessary. The only requirement is that they be thrust against the electrodes through one of the apertures with the switch button depressed so that each one becomes incinerated. The base of the needle can then be separated from a syringe by appropriate action in either of the apertures.

It will be understood that numerous variations may be made to the embodiment of the invention described above without departing from the scope thereof.

In particular the battery arrangement can be varied widely The battery may be a separate unit easily associated with the destruction device itself. It may also be a rechargeable battery unit releasably securable to the housing of the destruction device so that a fully charged battery unit can replace a discharged unit as and when required. Also, the recharging arrangement could be varied widely and, in the case of medical personnel who travel in vehicles for an appreciable length of time, the batteries could be charged from a motor vehicle battery through a suitable modifying circuit.

It has been found that with an arrangement as is described above, a single charge in the batteries has enabled about 180 hypodermic needles (depending on thickness) to be incinerated and a battery of the nature described is expected to accept at least 800 recharges.

Accordingly, although incineration of hypodermic needles using batteries would not normally appear to be feasible, it has now surprisingly been found that a most useful portable, self-contained unit utilising batteries as a power source can, in fact, be produced.

Claims (12)

Claims

1. A hypodermic needle destruction device comprising a housing, an access aperture through the wall of the housing and providing an access path for a hypodermic needle to contact a pair of electrodes within the housing, the electrodes being arranged to operatively contact a hypodermic needle introduced through said aperture at spaced positions along the length of the needle to short circuit the electrodes and thereby to become destroyed by electrically generated heat between said spaced positions, and an electrical supply circuit for supplying electrical power to the contacts, the device being characterised in that the electrical supply circuit is adapted to supply direct current power to the electrodes from an electrical battery power supply.

2. A device as claimed in claim 1 in which the device is self-contained and includes an electrical battery power supply.

3. A device as claimed in claim 2 in which the electrical battery power supply is located within the housing.

4. A device as claimed in claim 3 in which the batteries are rechargeable and the electrical circuit embodies a battery charger circuit adapted for releasable connection to an external supply of electrical energy for charging the batteries.

5. A device as claimed in claim 2 in which the electrical battery power supply is releasably attached to the device, the attachment embodying contacts for connecting the battery to the electrical supply circuit.

6. A device as claimed in any one of the preceding claims in which the electrical supply circuit embodies a normally open spring loaded switch connected between the battery power supply and the electrodes.

7. A device as claimed in any one of the preceding claims in which the electrical supply circuit embodies one or more displays for indicating the state of the battery power supply.

8. A device as claimed in any one of the preceding claims in which the housing has two access apertures, one having means for enabling a friction fit needle base to be parted from a syringe, and the other having a convergent zone adapted to grip a needle base and hold it angularly to enable a syringe to be unscrewed therefrom, each access aperture having a pair of electrodes associated therewith.

9. A device as claimed in any one of the preceding claims in which the battery power supply has a capacity of at least 2,2 ampere hours.

10. A device as claimed in any one of the preceding claims in which the battery power supply is a plurality of nickel-cadmium batteries.

11. A device as claimed in claim 10 in which the battery power supply is composed of four nickel-cadmium batteries.

12. A device substantially as herein described and exemplified with reference to the accompanying drawings.