Abstract:
The disclosed invention describes a device that operates to reduce the hazard involved in the disposal of conventional hypodermic needles used throughout the medical world. When the needle is presented to the inventive device, while still attached to the syringe, it is vaporized with its final connection point to the syringe sterilized. In a second version of the inventive device, the entire syringe, including the needle, is vaporized. The byproducts of the needle destruction process are sterile metal vapor such as iron oxide, water vapor and carbon dioxide. The heat is so intense that all organic compounds present within the needle are reduced to their basic elements of hydrogen, oxygen and carbon with trace amount of nitrogen and infinitesimal amounts of other trace elements. When the entire syringe is destroyed, all organic compounds of the plastic are reduced to the basic elements.

Description:
[0001]    Priority claimed on Ser. No. 60/281,840 filed Apr. 6, 2001 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention disclosed herein involves the establishment of an electric arc with either a hypodermic needle or a complete syringe suspended within said arc and, thus, vaporized by the heat of that arc. With the needle only destroyer version, the needle is placed such that one end is in contact with a heavy heat absorbent electrode. The second electrode is positioned at the end of the needle, such that it does not actually make contact with the needle. A high voltage establishes an arc between this second electrode and the needle, which acts as a conductive path for high current to form a plasma spot of intense heat forming a plasma spot which rapidly transfers the length of the needle until the needle is entirely consumed.  
           [0004]    2. Brief Description of the Prior Art  
           [0005]    There are a number of needle destroyers or needle storage techniques that are utilized by the medical industry. Presently, the primary method of needle disposal involves placing the needle, after first removing it from the syringe, in a box and disposing of the syringe in the conventional red bag. The box is designed to contain the needles and prevent any accidental punctures to those who are involved with disposing of the boxes. However accidental punctures are known to occur and the needles with the box are not sterile and can contaminate anybody accidentally coming into contact with them. Safe disposal of the boxes has become a major problem. Other methods of disposal involve cutting off, rather than removing, the needle from the syringe such that only one hand is required. In some cases, the syringe with the needle still attached are disposed of together in a special container but something still must be done with the container. Other forms of needle destruction are being considered for the market which involve heating or melting the needle with an electric current until it becomes soft with motor driven electrodes to maintain needle contact while the current is passed through it, causing it to melt. Although the heat from this process most likely sterilizes the needle, it is an expensive, clumsy method and requires continuous maintenance.  
         SUMMARY OF THE INVENTION  
         [0006]    Accordingly, the above problems and difficulties are avoided by the present invention which provides a syringe and/or needle destruction device having a housing, enclosing a pair of electrodes and an insertion port provided through the housing and one electrode for insertably receiving a needle. The other electrode is spring biased and includes a ceramic button separating direct engagement of the needle with the other electrode. A contact is connected with the other electrode when pivoting occurs to complete an electrical circuit. Since the needle is part of the circuit, high voltage and current will destroy and vaporize the needle.  
           [0007]    In another embodiment, a syringe and needle combination are placed in an enclosure and the electrical circuit is employed to destroy and vaporize the combination. A blower unit and toxic gas filter are employed to clear the enclosure of toxic and nontoxic fumes.  
           [0008]    The primary object of the subject invention is the total destruction of hypodermic needles and the like immediately after their use, such that containment, storage and transfer to another location for destruction or disposal would not be required.  
           [0009]    A second object of this invention is to sterilize at least to the point at which the needle was connected to the syringe or other medical instruments, such as in a IV tube or the like.  
           [0010]    Yet another object of the invention is to be able to expand the amount of energy to destroy the entire needle and syringe.  
           [0011]    A further object of the invention is to totally sterilize the resultant by products of this destruction.  
           [0012]    Still a further object of the invention is to accomplish all of the above in a safe and non-disruptive manner.  
           [0013]    Another object of the invention is to accomplish all of the above objects with a relatively small device.  
           [0014]    The final object of the invention is to accomplish all the other objects in such an economical manner as to make its application practical throughout the entire medical industry.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description, taken in connection with the accompanying drawings in which:  
         [0016]    [0016]FIG. 1 is a perspective view of a syringe and needle destruction device incorporating the present invention;  
         [0017]    [0017]FIG. 2 is a sectional view of the device shown in FIG. 1 illustrating a contaminated needle in position for destruction;  
         [0018]    [0018]FIG. 3 is an enlarged longitudinal sectional view of the device for destroying both a needle and syringe; and  
         [0019]    [0019]FIG. 4 is a circuit diagram for supplying high voltage and high current to establish connection and high current to sustain an arc and vaporize the needle.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
       [0020]    [0020]FIG. 1 shows a needle destroying module  1  having a cone-shaped hole with a large outer diameter  2  and a small inner diameter  3 . A person holding a used needle and syringe presents the needle to the cone-shaped hole and the outer diameter guides the needle into the small hole  3  so that it may enter the interior of module  1  and be destroyed.  
         [0021]    [0021]FIG. 2 shows the same shaped hole outer dimension  2  and inner dimension  3  in a cross sectional view with an electrode  4  and a needle  6  protruding through said hole. The needle  6  is attached to a header  7  which is attached to syringe  8 . When needle  6  enters the hole  3 , it comes in contact with a ceramic button  12  attached to a spring electrode  13 . The electrode  13  and button  12  are shown in a relaxed position in broken lines. When the needle is fully inserted into the device as shown, the needle header comes in contact with electrode  4  and the needle pushes electrode  13  which engages against contact  5  to turn the device “on”, as will be discussed in FIG. 3. A straight contact with electrode  13  would simply short the output. In order for an arc to be established, ceramic button  12  is inserted between the electrode and the needle, and this allows an arc to form between the needle and electrode  13  causing current to pass through the needle and into electrode  4 . The arc current is connected to a power supply through lines  14  and  11  to point X and Y. Electrode  4  pivots at point  10  which allows it to make contact with a contact  5 , which is connected to a power supply at point Z. Once the arc has been established, the needle will be consumed from the tip backwards towards the syringe. As this happens, spring electrode  13  which is anchored by a screw  16  to a block  15  will spring towards the syringe, causing the arc to be maintained and the needle to be consumed. When the burning is complete, there will be a tiny, melted and sealed stub of metal at the needle holder  7 . At this point, the syringe  8  is withdrawn and safely disposed of.  
         [0022]    Referring to FIG. 3, which is a cross-sectional view of the inventive device as it would be employed to destroy the entire needle and syringe, a syringe  20 , with used needle attached, is placed in chamber  21  by lifting lid  22  and resting the syringe and needle between electrodes  23  and  24  on supports  25  and  26 . Lid  22  is then closed using handle  28  causing it to press down and activate a switch  27 . Closing switch  27  causes a signal to connect via line  30  to a power supply module of FIG. 4 at point Z to start the syringe and needle destruction process. The destruction process is started by applying a high voltage between electrodes  23  and  24  via mounting screws  42  and  43 , lines  44  and  45  to points X and Y of FIG. 4 respectively. Electrodes  31 - 35  in combination with capacitors  36 - 41  act to enable a plasma arc to travel the full length of chamber  21 . When the voltage is first applied there is no current flowing and therefore no voltage drop across the capacitive reactance of capacitors  36 - 41  so the same voltage appears at electrodes  31 - 35  as is present on electrode  24 . This causes an arc to form between the electrode  23 , the needle and the closest electrode  31 . Once the arc is formed and the current starts to flow, there is a voltage drop across capacitors  36 - 41 . The values of these capacitors are selected such that the major voltage drop is across capacitor  36 . This causes the arc to transfer to electrode  32 . Again the selection of values for the capacitors causes the major drop now to be across capacitor  37 . In this manner, the arc is established down the chamber until it is between electrodes  23  and  24 . Once the arc plasma path has been established, its impedance is very low and electrodes  31 - 35  will no longer be involved. In some cases, depending on the size of the needle, syringe and chamber it may operate better to place capacitors  36 - 41  in parallel with each connected to its respective electrode  31 - 35  and electrode  24 . Since electrodes  23  and  24  have a large heat sinking capability and are highly conductive, they will not be consumed along with the needle and syringe.  
         [0023]    At the same time, the voltage is applied, the blower unit  48  is activated drawing air from chamber  21  via duct  47 . Air can enter chamber  21  only through a pinhole  52 , thus the strong suction of the blower unit substantially lowers the pressure in chamber  21  which facilitates the formation of the arc plasma. Once the plasma is formed, large amounts of gasses are produced which forms the breakdown of the plastic material of the syringe. Depending upon the type plastic used, there is a possibility that some of this gas might be toxic; thus, the output of the blower unit is connected to a toxic gas filter  51  through duct  50 . Normally the heat is so intense that everything is reduced to non-toxic byproducts. Once everything has been destroyed, chamber  21  is cleared of all gasses by the air flowing in through pinhole  52 .  
         [0024]    Referring now to FIG. 4, line power enters on line and common inputs  15  and  16  which is protected by fuse F 1 , and is rectified to Direct Current power by bridge diodes comprising D 1 , D 2 , D 3  and D 4  and filter capacitor C 1 . Input power is also fed to a primary transformer T 2 , the output of which is rectified by bridge diodes  5 ,  6 ,  7  and  8 , filtered by capacitor C 2  and regulated by a zener diode D 9  to supply drive to the oscillating circuit.  
         [0025]    Contact with point  5  of FIG. 4, which is connected to point Z, detects the presence of the needle and turns on timer and switch  18 , which connects the power from the input bridge rectifier on line  17  to power FET Q 1 , which is connected in half bridge configuration with power FET Q 2 . Diodes D 11  and D 12  across Q 1  and Q 2  respectively are added for protection, since even though FET transistors have these diodes built-in they are not often of high enough quality to provide the protection needed when working with high frequency arcs. IC chip U 1  supplies the high frequency drive for the output. The frequency is set by the value of capacitor C 4  and the adjustment of variable resistor R 2 . Resistor R 3  is provided to set the proper frequency limit. IC chip U 1  provides a high side driver of driving the top transistor for the bridge configuration, since Q 1  and Q 2  are high power FETS, the drive from U 1  needs to be augmented by complimentary emitter follower pairs Q 3  and Q 4  in the case of Q 1  and Q 5  and Q 6  in the case of Q 2 . Resistor R 5  and C 7  in the case of the drive for Q 1  and R 4  and C 5  in the case of the drive for Q 2  form a slight slowdown of the switching to eliminate radio frequency interference when the needle is arcing as well as providing a filter to prevent high frequency spikes from getting into the fairly sensitive U 1  chip. The power to operate the high side driver comes from the action of diode D 10  and capacitor C 6 . When Q 2  is “on”, capacitor C 6  is charged to the logic supply voltage through diode D 10 . When Q 1  is on, capacitor C 6  is connected to its source at the bottom, thus the supply voltage will always be maintained at the logic supply voltage plus the output voltage of the junction of Q 1  and Q 2 .  
         [0026]    Capacitor C 8  serves as a DC blocking capacitor allowing only the high frequency AC to pass from the half bridge to L 1 , C 9 , L 2 , and output transformer T 1 . The values of L 1 , L 2 , capacitor C 9  and the turns ratio of transformer T 1  are set when there is no needle present and the appropriate frequency is applied through CB. The resonance effect of L 1  and C 9  produce a slightly stepped up voltage at the primary of T 1 , and since no current is flowing at this time, there will be a drop across inductor L 2  and maximum output voltage will be achieved which is enough to establish an arc. Once the arc is established, the impedance of the primary of T 1  becomes very low, and the current flowing into the transformer and into the needle is limited by the value of inductor L 2 . All these values are selected carefully such that maximum current and power can be transferred into the arc when the needle is present and maximum voltage can be achieved when the needle is absent.  
         [0027]    While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.