RELATED APPLICATION 
     This application is a continuation-in-part of application Ser. No. 08/897,404 filed Jul. 21, 1997 which is a continuation of application Ser. No. 08/614,122 filed on Mar. 12, 1996. 
    
    
     BACKGROUND 
     1. Technical Field 
     This disclosure relates to a replaceable accessory cord and hands witch set for use with an electrosurgical instrument having no hands witch. More particularly, the replaceable accessory cord connects with the terminal of the electrosurgical instrument and the hands witch attached to the replaceable accessory cord mounts conveniently on the electrosurgical instrument, so the hands witch is accessible to the surgeon controlling the electrosurgical current delivery to a patient. 
     2. Description of the Related Art 
     Any electrosurgical instrument, such as scissors, graspers, a forceps, and the like, receives elecrosurgical current from an electrosurgical generator. A remote foot switch or hand switch connected to the electrosurgical generator normally controls the application of electrosurgical current to the electrosurgical instrument. Surgeons frequently prefer the convenience of using a hand switch. Since one hand of the surgeon holds the electrosurgical instrument, the finer actuation of a switch mounted on the electrosurgical instrument is convenient. 
     To minimize the cost of such electrosurgical instruments, suppliers frequently provide them without an integral hands witch for use by the surgeon. That omission benefits cleanability and sterilization after use if the electrosurgical instrument is reusable (as sterilization would ruin the hands witch circuitry), and minimizes replacement cost if the electrosurgical instrument is disposable. Consideration of the addition of a convenient finger switch may not be worth added expense. 
     Control of high frequency electrosurgical current at the electrosurgical instrument has long been a problem addressed in many ways. The use of fluidic control disclosed in U.S. Pat. No. 3,494,363 teaches squeezing a bulb or closing a vacuum port by the surgeon to control electrosurgical current delivery to a forceps. U.S. Pat. No. 3,752,160 is a disposable electrode switch attached to a forceps and functional when the tines are squeezed together. In particular, the electrosurgical current is transmitted in a monopolar application when a terminal on the cord contracts bare metal on the forceps. 
     Removable hands witches for electrocautery instruments have been described in U.S. Pat. No. 4,370,980 and 4,552,143. Conductive spring clips attach the hands witches to an electrosurgical instrument such as scissors, graspers, or a forceps. The electrically wired hands witch allows current passage through electrically conductive clips for attachment to the electrosurgical instrument. Cutting or cauterizing electrosurgical current passing through the hands witch depends on the operation of the button by the surgeon. Insulated handles of the electrosurgical instrument protect the surgeon from the electrosurgical current, but nothing protects the surgeon from the exposed conductive spring clips. U.S. Pat. No. 5,196,007 discloses a hands witch for use in conjunction with electrosurgical instruments with several types of mounts for attachment. These mounting methods include a tubular clip, Velcro®, tie straps, and dual clips for conjunction with slotted receptacles. 
     There has been a need to convert existing standard electrosurgical instruments such as “Endopath” instruments by Johnson &amp; Johnson or the“Endo” products of United States Surgical Corporation to hand switching with a simple and low cost replaceable accessory cord and hands witch set. No combination of a replaceable accessory cord and hands witch set substitutes for the regular cord set by electrically coupling the electrosurgical generator and the electrosurgical instrument connects to and additionally affording finger switching on the electrosurgical instrument. No replaceable cord and hands witch set provides universal mounting capability to support a nonintegral hands witch button. No replaceable cord and hands witch set provides an attached hands witch for finger actuation of the switch button adhesively mountable on any reusable or disposable electrosurgical instrument. No replaceable cord and hands witch set provides secure attachment of the hands witch to the electrosurgical instrument by means of a mount or support resistant to longitudinal, lateral, or circumferential movement relative to the electrosurgical instrument. 
     SUMMARY 
     A replaceable accessory cord and hands witch set is provided for use with conventional electrosurgical instruments which are not manufactured with resident switches for activation or electrosurgical current. The accessory cord may carry electrosurgical current to the electrosurgical instrument from an electrosurgical generator. The accessory cord may connect with a hands witch, which can include a small button, for activation of the electrosurgical current. 
     Attached to the switch is a mechanical connector for universal mounting on and attachment to electrosurgical instruments. The mechanical connector may have two adjustable wing-like extensions which wrap around and conform to various parts and surfaces of any electrosurgical instrument. The mechanical connector may be composed of a laminate of a malleable metal and an adhesive, the metal providing tear resistance and stiffness as well as bendability and conformability, and in conjunction with the adhesive, preventing longitudinal, lateral, or circumferential movement of the hands witch relative to the instrument. The mechanical connector can allow for convenient activation of electrosurgical current by the surgeon pressing the button with a finger. The mechanical connector may electrically insulate the hands witch from the instrument preventing leakage, stray current, or grounding by the surgeon. 
     Alternate embodiments of the replaceable accessory cord provide connections for monopolar and bipolar instruments, as well as varied male or female plug connectors for use with differing models and brands of electrosurgical generators and electrosurgical instruments. The accessory cord may be configured to plug into a footswitch outlet on electrosurgical generator models not equipped with hands witch connections. Additionally, the hands witch may have additional switches for selective activation of different types of electrosurgical waveforms (e.g. cut or coagulation). 
     Another embodiment comprises the hands witch and mechanical connector described wherein the hands witch connects with a jumper connector for use with a reusable accessory cord. The jumper connector would connect between the reusable accessory cord and the electrosurgical instrument. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various embodiments of the present disclosure are described with reference to the drawings herein: 
     FIG. 1 is a perspective side view of one embodiment of the replaceable accessory cord and hands witch set; 
     FIG. 2 is a perspective view with partial cutaway showing a replaceable accessory cord and hands witch set of an alternate embodiment wherein the switch is separate from the receptacle for pressure sensitive application to the handle of any electrosurgical instrument; 
     FIG. 3 is a perspective view of an embodiment of the mechanical connector shown in FIG. 1 attached to the back of the hands witch; 
     FIG. 4 is a perspective view with partial cutaway of the mechanical connector shown in FIG. 1 viewed from the button side of the hands witch through the hands witch support; 
     FIG. 5 is a partial view of one half of the mechanical connector shown in FIG. 1, on edge, enlarged to detail the layers of the adjustable laminate of the tab; 
     FIG. 6 is a perspective view with partial cutaway of the replaceable accessory cord and hands witch set for use with a monopolar electrosurgical instrument; 
     FIG. 7 is a perspective view with partial cutaway of the replaceable accessory cord and hands witch set for use with a bipolar electrosurgical instrument; 
     FIG. 8 is a perspective view with partial cutaway of the replaceable accessory cord and hands witch set as part of the complete monopolar electrosurgical circuit between the electrosurgical generator and the electrosurgical instrument; 
     FIG. 9 is a perspective view with partial cutaway of the replaceable accessory cord and hands witch set as part of the complete bipolar electrosurgical circuit between the electrosurgical generator and the electrosurgical instrument; 
     FIG. 10 is a perspective view with partial cutaway of an alternate embodiment for a jumper hands witch set for use with a reusable generator cord and a monopolar electrosurgical instrument; 
     FIG. 11 is a perspective view with partial cutaway of an alternate embodiment for a jumper hands witch set for use with a reusable generator cord and a bipolar electrosurgical instrument; 
     FIG. 12 is a perspective view with partial cutaway of an alternate embodiment of the replaceable accessory cord and hands witch set for use in place of a standard footswitch and with a monopolar electrosurgical instrument; and 
     FIG. 13 is a perspective view with partial cutaway of an alternate embodiment of the replaceable accessory cord and hands witch set for use in place of a standard footswitch and with a bipolar electrosurgical instrument. 
    
    
     DETAILED DESCRIPTION 
     A replaceable accessory cord and hands witch set  10  for use with an electrosurgical instrument  11  by a surgeon on a patient  12  in an electrosurgical circuit  13  is shown in FIGS. 1,  2 ,  6 ,  7 ,  8 ,  9 ,  12 , and  13 . The electrosurgical circuit  13  connects between an electrosurgical generator  14  and the electrosurgical instrument  11 . The electrosurgical instrument  11  is an example of conventional instruments which arc not manufactured with resident switches for activation of electrosurgical current. The electrosurgical instrument  11  has a proximal end  15  with an insulated handle  26  for holding by the surgeon and a distal end  16  which delivers electrosurgical current to the patient  12  through an end effector  27  such as scissors, graspers, or forceps. 
     An accessory cord  17  in FIGS. 1,  2 ,  6 ,  7 ,  8 ,  9 ,  12 , and  13  is used in place of a standard replaceable cord and electrically connects the clectrosurgical general  14  to the electrosurgical instrument  11 . The accessory cord  17  houses various conductors  51 ,  53 ,  54 , and  60  which carry either RF or activation current. The accessory cord  17  additionally connects via a switch cord  18  to a hands witch  19  which mounts on the instrument  11  and actuates the electrosurgical current. The switch cord  18  houses various conductors  51 ,  51   a ,  51   b ,  52 , and  60  which carry activation current. In alternate embodiments shown in FIGS. 6,  7 ,  8 ,  9 ,  12 , and  13 , the accessory cord  17  may connect with a connector  50  via a connector cord  59 . The connector cord  59  may house conductors  53  and  54 . The accessory cord  17 , the switch cord  18 , and the connector cord  19  are composed of, for example, polyvinylchloride. The various conductors  5 , 51   a ,  51   b ,  52 ,  53 ,  54 , and  60  are composed of a conductive metallic wire such as, for example, copper and said conductors are insulated, for example, with a polyolefin coating. 
     A hands witch support  24  as in FIGS. 1,  3 ,  4 , and  6  through  13 , houses first and second hands witch contacts  20  and  21 . The hands witch support  24  may be boxlike with a front, back, and four additional sides; the edges where the sides meet may be smooth and rounded. The hand switch support  24  is composed of, for example, a nonconductive, inexpensive molded thermoplastic, such as polycarbonate. The hand switch support  24  is also coated with polyurethane. The hand switch support  24  is electrically insulated from the first and second hand switch contacts  20  and  21 , the instrument terminal  22 , the instrument return terminal  23 , and the conductors in the accessory cord  17 . The first and second hand switch contacts  20  and  21  are inside the hand switch support  24  and may be mounted on ABS plastic. 
     An operating button  25  on the hand switch support  24  is accessible to the surgeon. The operating button  25  is composed of polycarbonate and is electrically isolated from the first and second hand switch contacts  20  and  21 , and the conductors in the switch cord  18 . The operating button  25  moves relative to the hand switch support  24 . To apply electrosurgical current to the patient  12 , the surgeon&#39;s finger presses the operating button  25 , thereby closing the first and second hand switch contacts  20  and  21 . Alternative plastic compositions of the hand switch support  24 , the operating button  25 , the accessory cord  17 , the switch cord  18 , the connector cord  59 , and the insulators for the various conductors  51 ,  51   a ,  51   b ,  52 ,  53 ,  54 , and  60  may be selected from available dielectric materials. 
     In FIG. 2, the hand switch support  24  is backed by a pressure sensitive adhesive  44  to mechanically connect the hand switch  19  to the instrument handle  26  preventing relative movement therebetween. This provides access to the hand switch  19  by a finger of the surgeon. The mechanical connection of the hand switch  19  is a mechanical connector  40  which appears in FIGS. 1 and 6 through  13 , and is best shown in FIGS. 3,  4 , AND  5 . The mechanical connector  40  has two wing-like extensions, or tabs  65 , which adjustably wrap around and conform to various parts and surfaces of the electrosurgical instrument  11 , generally on the instrument handle  26 . The mechanical connector  40  is a thin laminate composed of insulating tape  41 , a sheet of malleable metal  42 , additional insulating tape  43 , adhesive  44 , and a release liner  45 . The malleable metal  42  can be copper, aluminum, steel, or any other metal with a modulus of elasticity in tension between  20  and 20 millions of pounds per square inch. The malleable metal  42  provides stiffness and tear resistance, as well as conformability, and in conjunction with the adhesive  44 , prevents longitudinal, lateral, and circumferential movement of the hand switch  19  relative to the instrument  11 . The insulating tape  41  and  43  is “3M 7331” polyester tape, the adhesive  44  is “3M 9472” adhesive, the release liner  45  is “3M 4994” release liner, (as manufactured by the 3M Corporation of Minneapolis, Minn.), and the malleable metal  42  is 0.005 mils thick annealed or soft copper. Skilled artisans will appreciate that other forms for the metallic layer, such as wire, mesh, screen, or the like, could be used. 
     The mechanical connector  40  is attached to the back of the hand switch support  24 , by such as, for example, an ultrasonic weld. The mechanical connector  40  is perforated to accept rivets  47 . The mechanical connector  40  is placed between the hand switch support  24  and a weld plate  46  with molded rivets  47 , the weld plate  46  and rivets  47  are composed of polycarbonate. The rivets  47  are placed through the perforations in the mechanical connector  40  and are ultrasonically welded to the hand switch support  24 , thereby clamping the mechanical connector  40  between the weld plate  46  and the hand switch support  24 . Additional means of attachment of the mechanical connector  40  to the hand switch support  24 , such as by adhesives, should be obvious to those skilled in the art. 
     For use with monopolar electrosurgical instruments, as in FIGS. 6 and 7, the first end of the replaceable accessory cord  17  may have plug  31  with at least first and second contacts, a plug RF contact  36  and a plug activation return contact  37 , respectively, for electrically coupling with the electrosurgical generator  14 , at the RF current output  34  and the activation current input  39 , respectively. Within the accessory cord  17  are first and second conductors, an RF conductor  53  and an activation current return conductor  51 , respectively, which electrically couple with the plug RF contact  36  and the plug activation return contact  37 , respectively. The RF conductor  53  supplies high voltage electrosurgical current (also known as “RF current ”) to the electrosurgical instrument  11  and also carries a low voltage activation current. The activation current controls the discharge of RF current by the electrosurgical generator  14  to the electrosurgical instrument  11 . The activation current return conductor  51  provides the return path for the activation current from the hand switch  19  to the electrosurgical generator  14 . 
     The second end of the replaceable accessory cord  17  may split into a connector cord  59  and a switch cord  18 . The connector cord  59  has at least a first conductor, the RF conductor  53 , electrically coupled with a first contact, a connector RF contact  48  within the connector  50 , for electrically coupling the RF conductor  53  with a terminal  22  on the electrosurgical instrument  11 . The switch cord  18  has at least first and second conductors, a switch conductor  52  and the activation current return conductor  51 , respectively. The switch conductor  52  electrically couples with the RF conductor  53  within the accessory cord  17  at a RF-switch junction  58  and the activation current flows through the switch conductor  52 . The switch conductor  57  electrically couples with the first hand switch contact  20  in the hand switch  19 . The activation current return  51  electrically couples with the second hand switch contact  21  in the hand switch  19 . 
     When the hand switch button  25  is depressed by the surgeon, the electrical switch created by the first and second hand switch contacts  20  and  21  is closed and the activation current flows from the switch conductor  52 , through first and second hand switch contacts  20  and  21 , and through the activation current return  51  to the generator  14 . A reference in the electrosurgical generator  14  monitors continuity across the first and second hand switch contacts  20  and  21 . When continuity is detected, the electrosurgical current is activated. Another scheme for power control is disclosed in U.S. pat. No. 3,752,160 which is hereby incorporated by reference. When using a monopolar instrument as in FIG. 8, the return path for the electrosurgical current passing through the end effectors  27  of the electrosurgical instrument  11  is through the patient  12 , then through a return electrode  29  adhered to the patient  12 , which is finally electrically coupled to a RF return conductor  54  returning to the electrosurgical generator  14  at the RF return input  28 . 
     Bipolar electrosurgical instruments as in FIGS. 7 and 9 typically have first and second contacts, a terminal  22  for supplying electrosurgical current to the instrument, and a return terminal  23  for returning the electrosurgical current to the electrosurgical generator  14 . For use with bipolar instruments, the replaceable accessory cord may have a third conductor, such as, for example, an RF return conductor  54 . On the first end of the accessory cord, the RF return conductor  54  electrically couples with a third contact, a plug RF return contact  38 , the plug RF return contact  38  electrically coupling with the RF return input  28  on the electrosurgical generator  14 . The RF return conductor  54  would continue through the connector cord  59  and electrically couple with a connector RF return contact  49  within the connector  50 , the connector RF return contact  49  electrically coupling with the return terminal  23 . In the bipolar configuration, the RF conductor  53 , the switch conductor  52 , and RF switch junction  58 , the activation current return conductor  51 , and the first and second hand switch contacts  20  and  21 , all function as in the monopolar circuit. When using a bipolar electrosurgical instrument, the RF current travels through the electrosurgical instrument  11  to the end effectors  27  and then returns through the instrument  11  rather than through the patient  12  as in the monopolar circuit. The RF return conductor  54  within the accessory cord  17  is the return path for the electrosurgical current. 
     While the accessory cord  17  is shown permanently attached to the hand switch  19  in the FIGS. 1,  2 ,  6 ,  7 ,  8 ,  9 ,  12 , andl  3 , skilled artisans will know that a removable connector such as a jumper  30  in FIGS. 10 and 11, could be used to allow the separation of the accessory cord  17  and the hand switch  19 . The jumper  30  is an alternative embodiment which allows for connection of the hand switch  19  with a reusable accessory cord. The jumper  30  is composed of, for example, polyurethane surrounding ABS plastic upon which several contacts  48 ,  49 ,  55 ,  56  and  57  are mounted. In the monopolar configuration houses on a first end first and second contacts, a jumper switch contact  55  and a jumper RF contact  56 , respectively. The jumper switch contact  55  electrically couples with the activation current return conductor  51  in a reusable accessory cord and with the activation current return conductor  51  in the switch cord  18 . The jumper RF contact  56  electrically couples with the RF conductor  53  in a monopolar reusable accessory cord and with the connector RF contact  48 , which in this embodiment is housed in the jumper  30 . The jumper RF contact  56  also electrically couples with the switch conductor  52  in the switch cord  18 . The switch cord  18  and its conductors  51   a  nd  52  electrically couple with the hand switch  19  as previously described. 
     In the bipolar configuration of FIG. 11, the jumper  30  has an additional contact, a jumper RF return contact  57 , on the first end. The jumper RF return contact  57  electrically couples with the RF return conductor  54  in a bipolar reusable accessory cord and with the connector RF return contact  49 , which in this embodiment is housed in the jumper  30 . 
     A typical electrosurgical generator  14  creates first and second types of electrosurgical current waveforms, cutting and coagulation (“coag ”), respectively. Cutting and coag waveforms differ in their shapes and tissue effects. Typically the plug  31  and the electrosurgical generator  14  in a monopolar circuit have first, second, and third conjugating connections, the first for a cut activation current, the second for a coag activation current, and the third for RF current. The embodiments described thus far have considered activation of only one type of current waveform, either cutting or coag, by the hand switch  19  and have referred to activation of either through the singular use of the term “activation current.” Depending upon the configuration of the plug  31 , i.e., whether the plug activation return contact  37  is electrically coupled with an activation current input  39  which is cut or an activation current input  39  which is coag, the hand switch  19  may activate either a cutting current waveform or coagulation current waveform. 
     In an alternative embodiment of the replaceable accessory cord and hand switch set  10 , the plug  31  may have an additional contact and the accessory cord  17  and switch cord  18  may have an additional conductor to differentiate between cut and coag return current. For example, there may be first and second activation return conductors, a cut return conductor  51   a  and a coag return conductor  51   b , respectively, as shown under different circumstances in FIGS. 12 and 13. A cut-coag switch  35  could then be created by splitting the hand switch button  25  into a cut button  25   a  and a coag button  25   b , see FIGS. 12 and 13, or substitute a rocker button as in common on electrosurgical pencils with integral switching. The cut-coag switch  35  could similarly be integrated on the plug  31 , along the accessory cord  17 , or within the electrosurgical generator  14 . See FIGS. 8 and 9. 
     An alternative embodiment of the replaceable accessory cord and hand switch set  10  for use with an electrosurgical generator  14 , the electrosurgical generator  14  without hand switch contacts, but having footswitch contacts (e.g., certain neurosurgery model generators), is shown in FIGS. 12 and 13. When using the footswitch contacts to activate a hand switch  19 , the RF current and the activation current are isolated. Therefore, an additional conductor, an activation current conductor  60 , are employed in the accessory cord  17  and switch cord  18 , and a separate RF plug  31   a  is used to electrically couple the RF conductor  53  and plug RF contact  36  with the RF current output  34 . The activation current conductor  60  electrically couples on the first end to an activation current contact  61  in a footswitch plug  31   b . The activation current contact  61  electrically couples with the activation current output  62  on the electrosurgical generator  14 . The second end of the activation current conductor  60  electrically couples with the first hand switch contact  20  in the hand switch  19 . In this embodiment the hand switch  19  has first and second hand switch buttons, a cut button  25   a  and a coag button  25   b , respectively. The first hand switch contact  20  is common to both the cut button  25   a  and the coag button  25   b.    
     When the cut button  25   a  is depressed by the surgeon, electrical contact is made between the first hand switch contact  20  and the cut hand switch contact  21   a . The cut hand switch contact  21   a  is electrically coupled with a cut return conductor  51   a , the cut return conductor  51   a  similarly electrically coupled with a cut return contact  37   a  in the footswitch plug  31   b . The cut return contact  37   a  electrically couples with the cut signal contact  32  in the electrosurgical generator  14 . Similarly, when the coag button  25   b  is depressed by the surgeon, electrical contact is made between the first hand switch contact  20  and the coag hand switch contact  21   b . The coag hand switch contact  21   b  is electrically coupled with a coag return conductor  51   b , the coag return conductor  51   b  similarly electrically coupled with a coag return contact  37   b in the footswitch plug  31   b . The coag return contact  37   b  electrically couples with the coag signal contact  33  in the electrosurgical generator  14 . 
     Typically footswitch receptacles have a fourth input contact, a footswitch ground input  64 , for a ground conductor from a footswitch to prevent a short, a footswitch being composed of metal and placed on the floor. The hand switch  19 , being completely electrically insulated, has no need for an additional ground conductor. The footswitch plug  31   b  may provide a fourth contact, a footswitch ground contact  63 , the footswitch ground contact  63  not electrically connected to any conductor, but simply holding a place and proving a more secure mechanical connection between the footswitch plug  31   b  and the electrosurgical generator  14 . 
     It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely an exemplification of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
A replaceable accessory cord and hand switch set for an electrosurgical instrument wherein the accessory cord electrically couples an electrosurgical generator to the electrosurgical instrument. The hand switch is electrically coupled with the accessory cord. A button on the hand switch activates the flow of electrosurgical current in the instrument. An insulated mechanical connector on the hand switch conforms and adheres to the electrosurgical instrument, mounting the hand switch thereon, and preventing longitudinal, lateral, and circumferential movement therebetween. The hand switch is positioned on the electrosurgical instrument for easy access and control by the surgeon's finger.