TECHNICAL FIELD This invention relates to methods and apparatuses for destroying syringe needles.

BACKGROUND OF THE INVENTION

Disposable hypodermic syringes are widely used in hospitals and other medical facilities to draw body fluids from and to inject medications into patients. These syringes are made disposable because of the difficulties and inefficiencies involved in re-sterilizing syringes for reuse. Because the syringes are intended to be disposed of after use, a problem arises as to their safe post-use storage and disposal and in preventing them from being recklessly reused by others. By lav syringes may not be disposed cf as ordinary waste since their sharp needle tips, as well as disease causing organisms sometimes carried by them, may injure hospital and waste disposal personnel.

To dispose of syringes safely, devices have been devised that mechanically sever the syringe needles from their barrels. These are exemplified by those shown in U.S. Patent Noε. 4,255,996, 4,445,644 and 4,969,379. Though these devices do prevent reuse of syringes, a sharp needle stub remains intact and hazardous. Other types of syringe destruction devices grind the syringes into small pieces as shown in U.S. Patent No. 4,905,916. These

however do not provide for sanitary syringe resid disposal. Furthermore, their shearing action tends release fluid contaminates to ambience.

Incinerators have also been used to destroy syringe is a sanitary manner. Bulk incineration of accumulate syringes however poses the threat of injury still occurrin during accumulation and incineration input. Thus, portabl devices have been used which can incinerate the needles b passing an electric current through them. This approach i described in U.S. Patent No. 4,877,934 and 4,965,426 These devices however leave the barrel portion of th syringe with an opening at one end through whic contaminates may emerge to ambience. Furthermore, som pathogens contained within the needle and expelled from th syringe during insertion are not killed by the incineratio process.

It thus is seen that a need remains for a method an apparatus for destroying syringe needles in a mor effective and efficient manner. It is to the provision o such that the present invention is primarily directed.

SUMMARY OF THE INVENTION In a preferred form of the invention, a syringe needl destruction apparatus comprises a housing having an orific through which a syringe needle may be inserted into th housing. Crimping means are mounted within the housin adjacent the orifice for crimping a syringe needle t substantially seal the syringe. A needle tip contac element is mounted for movement along a needle path o travel within the housing in engagement with the needl tip. The apparatus also has means for establishing voltage across the crimping means and the needle ti contact element sufficient to burn that portion of th needle that extends between the needle crimp and tip. In another preferred form of the invention, a metho provides for destroying a portion of a hollow needle tha

extends outwardly from the barrel and hub of a syringe t a needle tip. The method comprises the steps of insertin the needle portion into an incinerator while leaving th barrel outside of the incinerator, forming a sealing crimp in the hollow needle, and burning the needle by passing an electric current through the needle between the needl crimp and tip.

BRIEF DESCRIPTION OF THE DRAWING Fig. 1 is a perspective view of a syringe needl destruction apparatus that embodies principles of th invention is a preferred form.

Fig. 2 is a perspective view of internal components of the apparatus of Fig. 1 shown with the housing and portion of the electric wiring removed for clarity.

Fig. 3 is a block diagram of the apparatus of Fig. 1. Fig. 4 is a flow diagram of the operation of th apparatus of Fig. 1 and method of the invention.

Figs. 5A-5F are a sequence of views, shown in cross section, of a portion of the apparatus of Fig. 1, showin a syringe needle being inserted, crimped, incinerated an severed in accordance with a method of the invention.

DETAILED DESCRIPTION With reference next to the drawings, there is shown an apparatus 10 having a housing 11. The housing 11 has a upper, self-contained unit 12 for syringe needle destruction operations that is mounted atop a lower, self- contained unit 13 in which residual syringe barrels may be collected and stored. The upper unit is shown in Fig. 2 as having a main power supply housing 15 to which an incinerator housing 16 is removably mounted. The incinerator housing 16 has a conically shaped needle receiving orifice guide 17 mounted about a central orifice. An annular activation switch, shown generally at 18, is mounted about the orifice guide 17 to the front of the

housing 16. The activation switch 18 is coupled by mea of conductors 21 with a controller 22 mounted within t housing 15.

A track 19 is mounted within the housing above t orifice guide 17. A spring biased carriage 20 is movab supported for travel upon the track 19. The carriage bears an electrode 23 with a concave face that faces and aligned with the needle orifice. The carriage 20 has fo wheels 24 rollably positioned upon the track 19, and a co spring 25 having one end mounted to the track so as to bi the carriage towards the needle orifice. A flexib conductor 26 connects the carriage electrode 23 to transformer 55 in all positions of the carriage along t track. A needle crimping means 30 is mounted in housing closely adjacent to the needle orifice. The crimping mea comprises an upper crimping plate 31 pivotably mounted o a pivot pin 34 above the orifice and a stationary low crimping plate 32 rigidly mounted below the needle orifice The lower plate 32 also functions as an electrode. conductor 33 couples the lower plate 32 with th transformer 55.

The apparatus also has means for severing needles tha includes a pivotable cutting blade or shearing plate 3 pivotable mounted on a pivot pin 34 in sliding contact wit the rear side of the upper crimping plate 31. Both th upper crimping plate 31 and the blade 36 extend throug aligned openings in two adjacent walls of the housing unit 15 and 16 so that one of their end portions is within th confines of the main power supply housing 15. An electri motor 40, mounted in the main power supply housing 15, ha its power output drive shaft coupled with both a crimpin cam 38 and a cutting cam 39. The motor is electricall coupled to the controller 22 by means of control line 37 as shown in Fig. 3. An ultraviolet light 41, mounted i the incinerator housing 16, is also coupled with th

controller by a conductor 42. A system ready LED type indicator lamp 48, a trouble/burn process LED type indicator lamp 49, and a full status LED type indicator lamp 50 are all mounted to the front of the incinerator housing 15. Each is connected to the controller 22 via a line or cable 51 of ganged conductors.

As shown best in Fig. 3, transformer 55 is coupled to the controller 22 by a conductor 56. A high temperature sensor is mounted on the transformer 55 coupled with the controller by conductor 58. The carriage electrode 23 and the lower crimping plate/electrode 32 are coupled with the transformer by means of conductors 26 and 33, respectively.

A photoelectric burn done sensor is also mounted within the incinerator unit 16. This sensor is mounted so that the carriage 20 interrupts its beam when the carriage is at a position closely adjacent the orifice. An unεhown motor home sensor is mounted adjacent the motor 40 to indicate that the cams have completed a full cycle so as to have returned to their initial, apparatus-ready positions prior to apparatus activation.

Finally, the housing lower portion 13 has a door 65 that is provided with a slot 66 located on its top edge. A removable bin 67 is located within the housing lower portion 13 which has a contoured chute 68 sized to extend through the door slot 66 when the door is closed.

OPERATION Operation of the apparatus may best by understood by reference to Figs. 5A-5F. In Fig. 5A a conventional syringe S having a barrel B, a plastic needle hub H, and a metallic, needle N is guided by an operator, such as a nurse, nurse's aid, or hospital attendant, into the needle receiving orifice. The conical shape of the orifice guide 17 serves to guide the needle tip into and through the orifice. As the needle N is pushed into the incinerator housing 16 it passes between the crimping plates 31 and 32

^W092 """ ⁶ - ⁶ - PCT/US92/0.035

bringing its tip into contact with the carriage electro 23. As the needle is pushed further into the unit drives the carriage 20 away from orifice along track 19 against the bias provided by spring 25, as shown in Fi 5 5B, until either the syringe hub H abuts the conica orifice guide, as shown in Fig. 5C, or until the carriag has traveled the maximum distance allowed by the track 1 by engaging an unshown carriage stop. Carriage movemen is limited to insure that an operator does not attempt ^' t

10 incinerate the entire length of an extraordinarily lon needle in a single operations and thereby exceed powe capacity limits. Such long' needles are instead incinerate in a succession of operations as such operations are herei described.

15 Once the syringe is fully inserted into th incinerator, as shown in Fig. 5C, the operator depresse the activation switch 18 as with his or her finger whil holding the syringe barrel. In response to this th controller 22, which is of conventional construction tha

20 preferably employs a microprocessor chip, energizes th motor 40 and the trouble/burn process lamp 49, and de energizes the system ready lamp 48. The motor the commences o rotate the crimping cam 38 and the cutting ca 39. The crimping cam 38 engages and pivots the uppe

25 crimping plate 31 about pivot pin 34 thereby crimpin needle N between the upper crimping plate 31 and the lowe crimping plate 32, as shown in Fig 5C. The crimping of th needle serves the dual function of sealing the syring needle residual stub and providing an electric contact wit

30 the needle at the crimp site since the lower plate 32 als functions as an electrode.

With the needle crimp still held firmly by the plate

31 and 32, the controller next energizes the electrodes 2 and 32 by coupling them with the transformer 55 and its

35 volt A.C. voltage. For the electrical resistance provide by a 16 gauge stainless steel needle portion of a lengt

approximately three an one half inches between the electrodes 23 and 32, approximately 40 amps is caused to flow through it causing the needle portion to burn and char throughout in less than a second. This general voltage level is preferred as substantially higher voltage levels can cause sparking and welding of the needle to the electrodes and substantially lower voltages can lead to insufficient or too slow incineration.

During the brief period of incineration, the spring 25 continuously urges the two electrodes towards one another. This serves to maintain them in good contact with the needle and also to create a compaction force on the needle char to lengthen the time that the charring needle provides a conductive path between the electrodes. As incineration progresses and the needle weakens, it becomes unable to hold the electrodes apart. As a result, the carriage and electrode 23 then advance towards the crimping means, as shown in Fig. 5D. This causes the needle to fold and twist which usually forms it into a compact, single extension needle residue char of a coil-like shape that usually remains attached to the unburned portion of the needle at its crimp.

Upon return of the carriage to its initial position adjacent the crimping means 30, the carriage interrupts the photoelectric burn done sensor beam which indicates to the controller that the burn process is complete. The controller then de-energizes the electrodes. If the burn done sensor beam has not been interrupted after expiration of a two second time period from burn initiation, the controller de-energizing the electrodes anyway. It is at approximately this time that the cutting cam 39 has rotated to a position forcing the cutting blade 36 downward through the needle char closely adjacent the crimp. The cutting blade severs the residue char whereupon it free falls, as shown in Fig. 5E, to the bottom of the incinerator. With the crimping plates once again separated, the needle crimp

is released enabling the operator to remove the syringe a its short, sealed, needle stub from the incinerator un and place it in the lower storage unit. Once the cams ha fully returned to their initial positions a motor home cycle complete sensor inputs a signal to the controller which de-energizes the motor 40, re-energizes the syst ready lamp 48, and de-energizes the trouble/burn process to indicate that the apparatus is reset and ready incinerate another needle. Though most pathogens within the needle are killed its incineration, some heat resiεtent ones may not b Also, some pathogens may be expelled during insertion a operation of the needle into the apparatus. For the reasons the incinerator is also provided with a germicid ultraviolet light 41 which is energized by the controll for a short time following needle severance to kill su remaining pathogens. Once the fill sensor lamp indicat that the incinerator housing 16 is filled to capacity, may by removed for disposal. Alternatively, t incinerator housing may have a disposable collecting b removably mounted within the incinerating housing 16.

From the foregoing, it is seen that a method a apparatus for destroying syringe needles is now provid which overcomes problems associated with those of the prio art. It should however be understood that the jus described embodiment merely illustrates principles of t invention in a preferred form. Many modifications additions and deletions may, of course, be made theret without departure from the spirit and scope of th invention as set forth in the following claims.