Abstract: An adapter unit for a mechanical tissue cutting implement such as a shaver, morcellator or the like includes a mounting block from which an electrically insulating sheath extends. The sheath fits over the cannula or shaft of the cutting implement, and is secured in alignment and attached so that the cutting tip, for example, the tool and its window in the cannula tip, are exposed through the sheath. A conductor, which may be a conductive layer, extends along the length of the sheath and is exposed to form a distal electrode at the tip in close proximity to the opening, constituting one electrode of a bipolar electrode arrangement at the exposed tool. The other electrode is provided by electrical connection to the implement itself, so that a high current density path is formed through tissue in the cutting region.

Abstract: An electrosurgical device for performing uvulopalatoplasty is provided. The device of the present invention includes two configurations. The first configuration includes a handle having an actuator mechanism which actuates a barrel fixedly mounted to a handle. This embodiment is contemplated to be disposable for single patient use. The second configuration includes a handle having an actuator mechanism having a detachable barrel. Both devices of the present invention are designed to fit easily into a patient's mouth and maximize the surgeon's manual control.

Abstract: A method is described for the operation of a radiofrequency ablation instrument comprising a radiofrequency energy source having a plurality of regulatable outputs, with a plurality of electrodes being connectable to its outputs. A respective power value and/or current value representative of the power and/or the current transmitted by the radiofrequency energy source is detected for each output. The voltage delivered from the radiofrequency energy source is regulated in dependence on the detected power value and/or current value in such a way that the latter corresponds substantially to a predetermined power value and/or current value. A predetermined phrase relationship is in each case maintained between the currents or between the voltages at the outputs of the radiofrequency energy source. Furthermore, a corresponding apparatus is described.

Abstract: An electrical connecting cable for bipolar electrosurgical scissors. The cable has a pair of insulated parallel conductors having insulating coatings. The coatings are separably connected. A slidable grommet is mounted to the cable. The conductors are partially separable from each other. A plug is mounted to one end of the cable. Spring loaded connectors are mounted to the other end of the cable.

Abstract: An apparatus for thermal treatment of a tissue mass having an elongated housing having a proximal and a distal end and defining a longitudinal axis, and further including at least two electrodes supported at its distal end and mounted for rotation to facilitate entry and passage through a tissue mass. A drive shaft may be disposed within the elongated housing and operatively engageable with the electrodes for causing their rotational movement. The apparatus may include an electrode gear and a drive shaft gear in cooperative engagement whereby rotation of the drive shaft causes corresponding rotation of the electrodes. Preferably, a motor is operatively connected to the drive shaft causing its rotational movement. Desirably, the distal end of the electrodes are threaded. A method for thermally treating a tissue mass is disclosed.

Abstract: In the present invention, a surgical trocar is adapted to capacitively couple electrosurgical energy to specially adapted cordless electrosurgical instruments. In one embodiment of the present invention, an electrosurgical trocar includes a cannula, a capacitive electrosurgical adapter and a locking connector adapted to connect the cannula to the capacitive electrosurgical adapter. The cannula is an elongated tube which may be inserted into a body cavity, duct or vessel. The electrosurgical adapter includes a housing with an elongated central aperture, an adapter proximal capacitor plate and an adapter distal capacitor plate positioned in and extending axially along the elongated aperture, first and second electrical conductors, first and second external conductors, a compression mechanism, an outer housing and an electrical cord.

Abstract: The present invention is directed to systems, methods and apparatus for removing implanted objects from a patient's body, particularly implanted endocardial or epicardial pacemaker leads and transvenous defibrillation leads from a patient's heart. In one aspect of the invention, an electrosurgical catheter is advanced to a position within the thoracic cavity adjacent a portion of a pacemaker lead that is affixed to heart tissue. Preferably, the catheter is advanced over the pacemaker lead, i.e., using the pacemaker lead as a guidewire, to facilitate this positioning step. Once the distal end of the catheter reaches a blockage, or a portion of the lead that is attached to fibrous scar tissue, a high frequency voltage difference is applied between one or more electrode terminal(s) at the distal end of the catheter and one or more return electrode(s) to remove the scar tissue around the lead.

Abstract: Bipolar electrosurgical scissors are disclosed having a pair of blades joined for relative movement in a scissor-like action between open and closed positions. At least one of the blades comprises a tissue contacting surface and first and second spaced apart electrodes extending along the surface. Current flow between the first and second electrodes promotes hemostasis in tissue contacting the surface. Preferably, each blade of the scissors includes first and second spaced-apart electrodes.

Abstract: An electrosurgical cutting apparatus for performing laparoscopic section of an organ makes use of an electrical current transporter. The transporter includes a conducting wire, electrical insulation portions around the conducting wire at the first end and at the second end, forming respectively a first and a second insulated end and defining a non-insulated cutting portion between said first insulated end and said second insulated end, and a first fastening device located at the first end of the conducting wire and a second fastening device located at the second end of said conducting wire. The second fastening device is in electrical contact with the conducting wire.

Abstract: An electrosurgical instrument, which is used to treat tissue in the presence of an electrically-conductive fluid, comprises an instrument shaft and an electrode assembly at one end of the shaft. The electrode assembly comprises a tissue treatment electrode (11) and a return electrode (12) which is electrically insulated from the tissue treatment electrode by means of an insulation member (15). The tissue treatment electrode (11) is exposed at the extreme distal end of the instrument, and the return electrode (12) has a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member (15). The instrument further comprises feed means (17) for feeding electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode (11) in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment and the return electrode (12).

Abstract: The present invention is directed to a bipolar electrosurgical instrument suitable for use in mesentery tissue and other suitable tissue structures, including vessels. A bipolar electrosurgical instrument according to the present invention includes an end effector which includes a tissue slot and electrodes arranged on either side of the tissue slot. The opposing electrodes are electrically connected such that tissue passing through the slot is electrically treated with electrosurgical current passing laterally through the tissue. An end effector according to the present invention further includes a tissue separator arranged at the end of the slot to divide tissue as it is passed through the slot and after it is treated.

Abstract: A bipolar surgical device includes a pair of actuable jaws. A first electrode member which optionally includes a line of electrically coupled tissue-penetrating elements is formed on one of the jaws, and a second electrode member which optionally includes a line of electrically coupled tissue-penetrating elements is formed on the same or the other jaw. The electrode members are laterally spaced-apart and arranged in a parallel, usually linear manner so that the lateral distance therebetween remains generally constant. In operation, tissue may be grasped between the jaws so that the electrode members contact and/or the tissue-penetrating elements enter into the tissue. By energizing the electrode members at opposite polarities using a high frequency energy source, tissue between the jaws will be heated, coagulated, and/or necrosed, while heating of tissue outside of the lines will be minimized.

Abstract: A surgical handpiece tip with at least two coaxially spaced electrically conductive tubes. The tubes are separated by an electrical insulator. The interior of the inner tube is used for aspiration of liquefied tissue. The distal portion of the interior tube terminates just inside of the outer tube so as to form a boiling region. Electrical current is passed between the inner and outer tube to rapidly boil any surgical fluid in the boiling region. The boiling fluid rapidly expands out of the ring between the tubes and contacts the targeted tissue, thereby liquefying the tissue and allowing the tissue to be aspirated.

Abstract: A bipolar forceps for sealing, cauterizing, coagulating and/or cutting vessels and vascular tissue at multiple sites includes a pair of multi-pronged jaw members pivotally attached in opposing relation relative to one another and selectively movable from an open position wherein the jaw members are disposed in spaced relation relative to one another to a second clamping position wherein the jaw members cooperate to grasp tissue therebetween. The forceps also includes at least one electrode disposed on the inner facing surface of each prong of the jaw members and a switch for selectively controlling electrosurgical energy to each electrode. The electrodes on each of the jaw members can be activated simultaneously, sequentially, or in a multiplexed fashion. The disclosure also relates to a method of sealing, cauterizing, coagulating and/or cutting vessels and vascular tissue at multiple sites without manipulation of the forceps.

Abstract: Disclosed herein is a new arthroscopic probe with a concave distal tip which simultaneously constrains and cuts tissue. It is particularly adapted to cutting ligaments and tendons. Also disclosed is a thermal energy delivery apparatus which includes (a) a probe means with a distal end and a proximal end, wherein the distal end has a concave tip; (b) a first electrode means positioned at the distal end of the probe means, wherein the first electrode means is configured to deliver sufficient thermal energy to cut ligaments or tendons; and (c) a cabling means coupled to the proximal end of the probe means.In another embodiment of the invention a controller for controlling the delivery of energy and liquid to a surgical instrument with a temperature sensor is disclosed. The energy is supplied by an energy source and the liquid is supplied by a pump. The controller includes a temperature and a flow regulator. The temperature regulator is coupled to the energy source and coupled to the pump.

Abstract: A safety-shielded trocar having an obturator with a linear cutting edge surface defining a base width substantially less than the diameter of the safety shield is disclosed. When the trocar is inserted through tissue, the tissue dilates from the width of the linear incision to accommodate the size of the safety shield of the trocar, thus making it possible to provide an access opening greater than the incisional width made by the linear cutting edge surface of the obturator. In a preferred embodiment, the safety shield has a shield tip region which is asymmetric to facilitate the dilation of the tissue as the trocar is inserted.

Abstract: Systems and methods are provided for removing fatty tissue underlying a patient's epidermis (e.g., blepharoplasty, brow lifts, eyelid shortening procedures, and the like). These methods include positioning one or more active electrode(s) and one or more return electrode(s) in close proximity to a target site on an external body surface of the patient. A high frequency voltage difference is applied between the active and return electrode(s), and the active electrode(s) are translated across the external body surface to create an incision therein. The bipolar configuration controls the flow of current to within and around the distal end of the probe, which minimizes tissue necrosis and the conduction of current through unwanted paths in the patient. The residual heat from the electrical energy also provides simultaneous hemostasis of severed blood vessels, which increases visualization and improves recovery time for the patient.

Abstract: The invention provides methods, systems and apparatus for electrosurgically treating tissue particularly within the uterus and prostate. In an exemplary method, a surgical instrument comprising an elongate shaft having a proximal end and a distal end, an active electrode near the distal end, and a return electrode is introduced into the uterus. An electrically conductive fluid is then introduced into the uterus to distend the uterus and to form an electrically conductive path between the active electrode and the return electrode. The active electrode is then contacted against tissue within the body cavity. Current is passed between the active electrode and the return electrode while the active electrode is contacting the tissue. The active electrode is provided with a surface area which is selected to produce a power density sufficient to resect or coagulate tissue. The active electrode is then moved along and through the tissue to remove, coagulate or vaporize the tissue.

Abstract: Systems and methods are provided for resecting and/or ablating tissue within the urethra, prostate and bladder, such as transurethral resection of the prostate (TURP). A resectoscope includes an active loop electrode and a return electrode oversheath for applying high frequency electrical energy therebetween. Electrically conductive fluid, e.g., isotonic saline, is delivered to the target site to generate a current flow path between the active and return electrodes, and it allows for a new mechanism for ablation or molecular dissociation of tissue. The isotonic saline also eliminates the complications associated with the use of hypotonic (low salt) irrigating solutions.

Abstract: A cutting device for use in electrotomy is disclosed for use with a high frequency generator to make a cut in a cutting direction. The cutting device comprises a carrier element, and first and second electrodes each connected to the high frequency generator. Each electrode has a proximal portion attached to the carrier element and an elongated distal leg portion which terminates in a distal end. An insulation element connects the distal ends to each other with predetermined spacing between them. The elongated segments oppose each other and are aligned to be co-linear with each other along the cutting direction.

Abstract: A bipolar electrosurgical cutting and coagulating instrument for cutting and coagulating tissue in open surgery. The instrument comprises a handle member from which an electrically conductive first forceps rod and an electrically conductive second forceps rod extend in opposing relationship to each other. An electrically conductive wire extends from the handle member to reside within a longitudinal lumen of the second forceps rod. The first forceps rod is partially movable proximally within the handle member wherein a movable electrical conduit resides. Proximal movement of the first forceps rod causes the rod to contact and move the conduit which, in turn, causes distal movement of the conductive wire with which the conduit is in contact. Such distal wire movement causes the distal end of the wire to extend distally from the second forceps rod.

Abstract: In the present invention, a surgical trocar is adapted to capacitively couple electrosurgical energy to specially adapted cordless electrosurgical instruments. In one embodiment of the present invention, an electrosurgical trocar includes a cannula, a capacitive electrosurgical adapter and a locking connector adapted to connect the cannula to the capacitive electrosurgical adapter. The cannula is an elongated tube which may be inserted into a body cavity, duct or vessel. The electrosurgical adapter includes a housing with an elongated central aperture, an adapter proximal capacitor plate and an adapter distal capacitor plate positioned in and extending axially along the elongated aperture, first and second electrical conductors, first and second external conductors, a compression mechanism, an outer housing and an electrical cord.

Abstract: Open surgery and endoscopic versions of an electrosurgical cutting instrument incorporating a unique cutting arrangement for opening and closing the cutting edge parallel to an anvil surface resulting in a simultaneous cutting of a linear section of tissue, large vessels, or a group of vessels. Simultaneous with the cutting, the instrument further being capable of either a monopolar or bipolar cauterization of tissue. Also disclosed herein, are methods for use of the various electrosurgical cutting instruments.

Abstract: A bipolar endoscopic scissors is provided with scissor blades where at least one scissor blade is coated with an electrically non-conductive ceramic from its cutting edge along at least a contiguous portion of its shearing surface. The coated blade is provided with a cutting edge having an obtuse included angle which is preferably between approximately 95.degree.-140.degree., and more preferably between 110.degree. and 120.degree.. The blades according to the invention may be configured in several different ways with regard to the number of layers and types of material used, the extent of the ceramic coating, and whether one or both blades are configured in an identical manner. The blades according to the invention having cutting edges defined by obtuse angles cut well and provide a good cutting feel to the practitioner while preventing the ceramic coating from chipping at the cutting edge.

Abstract: A laparoscopic bipolar electrosurgical instrument can apply a large closure force between its jaws without damaging the small yoke assembly.

Abstract: A bipolar electrosurgical instrument having a pair of relatively moveable jaws, each of which includes a tissue contacting surface. The tissue contacting surfaces of the jaws are in face-to-face relation with one another, and adjacent each of the tissue contacting surfaces are first and second spaced-apart electrodes that are adapted for connection to the opposite terminals of a bipolar RF generator so as to generator a current flow therebetween. The first and second electrodes of one jaw are in opposed relation, respectively, with the first and second electrodes of the other jaw. The tissue contacting surfaces are disposed between the electrodes on each jaw, and the first opposed electrodes of each jaw are connectable to one terminal of the bipolar RF generator, while the second opposed electrodes of each jaw are connectable to the other terminal of the bipolar RF generator.

Abstract: An electric cautery used with an endoscope includes a hood mounted to a distal end of an insertion part of the endoscope. An electrode is provided to an inner surface and/or an end surface of the hood. A cable is provided to supply electricity to the electrode. The cable extends in the channel of the insertion part of the endoscope.

Abstract: A device and method for treating infected or damaged heart valve tissue by selectively heating, applying pressure, or both to the heart valve tissue to sterilize any infected portion of the tissue, reshape any misshapen portion, effect selective thinning of any thickened portion, and reduce the floppiness of any selected portion. The heat can be applied to or induced in the heart valve tissue.

Abstract: An electrosurgical instrument includes an electrode assembly having an electrode mechanically interlocked with a non-conductive body to as to form a gap therebetween. In one embodiment, complimentary surface features of the respective electrode and the non-conductive body interlock the components of the electrode assembly. In another embodiment, the electrode assembly includes a generally spherical electrode that is rotatable with respect to a non-conductive hood. A gap is formed between an outer surface of the electrode and an inner surface of the hood.

Abstract: A cooled electrosurgical system includes an electrosurgical device having at least one electrode for applying electrical energy to tissue. In one embodiment, the electrode includes an internal cavity in which a cooling medium such as water is contained. The internal cavity is closed at the distal end of the device such that the cooling medium is contained within the electrode at the surgical site such that the cooling medium does not contact the tissue being treated.

Abstract: An electrosurgical instrument having an active electrode with a portion that is coated with an insulative material. An exposed portion of the electrode is effective to treat tissue while the insulative coating minimizes energy dissipation into surrounding isotonic solution.

Abstract: A method and apparatus for destroying blood borne pathogens is disclosed which utilizes a low intensity direct current to generate positive particles from various metals which destroy viral pathogens. A first electrode comprised of a metal such as silver is inserted into a patient's venous system. Then, a second electrode is placed on the patient's exterior in the vicinity of the first electrode. A low intensity direct current is applied to the first metal electrode which releases silver cations to be bonded to the virus, resulting in the denaturing of the virus. The first electrode is placed in the venous system of the infected patient via a catheter.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within the head and neck of a patient's body, particularly including tissue in the ear, nose and throat. In one aspect, a method is provided for reducing the volume of enlarge swollen tissue in the patient's nose, such as swollen nasal tissue, mucus membranes, turbinates, polyps, neoplasms, cartilage (e.g., the nasal septum) or the like. In particular, the turbinates are treated by positioning one or more electrode terminal(s) adjacent to the turbinates, and delivering electrically conductive fluid, such as isotonic saline, to the nasal cavity to substantially surround the electrode terminal(s) with the fluid.

Abstract: A bipolar endoscopic instrument has a tubular stem fitted at its distal end with two arms pivotally supported on a shaft. The arms are pivoted by actuating an axially displaceable push/pull element mounted in the stem. The arms are connected through mutually electrically insulated leads to the terminals of a high-frequency power source, the shaft having two mutually insulated, electrically conductive segments each electrically connected to one of the electrical leads and the arm associated with this lead.

Abstract: An intravascular device and methods for forming multiple percutaneous myocardial revascularization (PMR) holes in a heart chamber wall simultaneously. One device includes a basket formed of flexible arms carrying cutting probes over their length. The basket arms are outwardly arcuately biased so as to assume an outwardly bowed, arcuate shape when unconstrained. The device includes an inner shaft distally secured to a proximal portion of the basket and slidably disposed within an outer shaft. The inner shaft and collapsed basket can be retracted within the outer shaft, delivered intravascularly to the left ventricle, and distally advanced, forcing the basket to assume the bowed shape. Radio frequency current supplied to the electrical cutting probes burn holes into the ventricle wall and myocardium. One embodiment has high pressure fluid jet cutting means. Another embodiment uses a basket as an anchor to position a steerable cutting probe.

Abstract: The invention concerns a high-frequency surgical instrument comprising two electrodes which are designed as forceps jaws and to which a high-frequency current from a high-frequency generator can be applied such that a high-frequency current flows between the jaws through the area of tissue to be treated. The instrument according to the invention is characterized in that, for alternative cutting and coagulation, an electrically non-conductive spacer is provided which is introduced between the electrodes when tissue is being cut. At least one duct is provided for flushing and/or removal purposes.

Abstract: In an electrosurgical instrument for the treatment of tissue in the presence of an electrically conductive fluid medium, a bipolar electrode assembly has an active electrode with an exposed tissue treatment portion, a return electrode having an exposed fluid contact surface, and an insulating member positioned between and electrically insulating the active electrode and the return electrode. The insulating member serves to space apart the exposed active electrode treatment portion and the exposed fluid contact portion of the return electrode. The dimensions and configurations of the exposed portions of the electrodes and of the insulating member are such that, when the electrode assembly is immersed in a conductive fluid medium, the ratio between the longest and shortest conduction path lengths between the active and return electrodes is greater than or equal to 1.25 to 1. The invention also includes a combination of an electrosurgical instrument and a radio frequency generator.

Abstract: An Rf energy applicator with a working end that carries a bi-polar Rf electrode system for creating a Rf-tissue interaction or ionothermal effect in subsurface tissue (a first ionothermal system) which effect is focused by concurrent actuation of a photonic tissue-sensitizing system or photoconductance system (a second ionothermal system). The photonic energy system is adapted to create a "lens electrode" in subsurface tissue that enhances the targeted tissue's conductance of Rf current which serves as a means of focusing Rf ionothermal effects at a subsurface level. A dosimetry control system is provided that controls the dose and timing of Rf energy delivery as well as the dosimetry of photonic energy delivery. The ionothermal applicator has a handle portion coupled a tubular extending member. The distal termination of the probe has at least one pair of opposing conductive electrodes in a spaced relationship around a perimeter of the distal termination of the extending member.

Abstract: A bipolar electrosurgical instrument having an improved pivot screw design is disclosed. The bipolar electrosurgical instrument has a first half which has a first pivot surface and a first bore. The first bore has a first stepped portion and an elongated portion proximate to the first pivot surface. A second half has a second pivot surface and a second bore having a second stepped portion. An insulating material is disposed on the first pivot surface and the elongated portion of the first bore. A first insert having a third bore in which the third bore has first threads is disposed in the second bore and prevented from entering the first bore by the second stepped portion. A second insert having a fourth bore is disposed in the second bore between the second stepped portion and the first insert and prevented from entering the first bore by the second stepped portion.

Abstract: A device for cutting tissue from a body comprises a cutting member including a cable formed of first and second conductors insulated from one another. The first and second conductors are arranged in an alternating distribution along the cutting member with the first conductor having a plurality of exposed portions forming a plurality of first electrodes and the second conductor having a plurality of exposed portions forming a plurality of second electrodes. The first and second electrodes are distributed along a cutting edge of the cutting member.

Abstract: A clamping force mechanism and its method of use with electrosurgery allow a user to seal and/or join patient's particular vascular tissue; the mechanism is elongate with user and patient ends. An actuator is at the user end and the effectors are at the patient end. Each effector has a face of an area to contact the particular vascular tissue. A lost motion connection transfers user actuation to the effectors to hold a predetermined clamping force during electrosurgical tissue sealing. A yielding member in the loss motion connection clamps the particular tissue between the faces with a predetermined force. The yielding member is a spring, slip clutch or hydraulic coupling possibly near the actuator. An active electrode is carried on one end effector and a return electrode contacts the tissue so an electrosurgical energy supply connected thereacross delivers energy therebetween. A feedback circuit responds to parameters of energy delivered to tissue.

Abstract: A bipolar surgical device includes a pair of actuable jaws. A first electrode member which usually includes a line of electrically coupled tissue penetrating elements is formed on one of the jaws, and a second electrode member which usually includes a line of electrically coupled tissue penetrating elements is formed on the same or the other jaw. The electrode members are laterally spaced-apart and arranged in a parallel, usually linear manner so that the lateral distance therebetween remains generally constant. In operation, tissue may be grasped between the jaws so that the electrode members contact and/or the tissue penetrating elements enter into the tissue. By energizing the electrode members at opposite polarities using a high frequency energy source, tissue between the jaws will be heated, coagulated, and/or necrosed, while heating of tissue outside of the lines will be minimized.

Abstract: An electrosurgical instrument, which is used to treat tissue in the presence of an electrically-conductive fluid, comprises an instrument shaft and an electrode assembly at one end of the shaft. The electrode assembly comprises a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member. The tissue treatment electrode is exposed at the extreme distal end of the instrument, and the return electrode has a fluid contact surface spaced from the exposed end of the tissue treatment electrode by the insulation member. The instrument further comprises feed means for feeding electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment and the return electrode.

Abstract: An electrosurgical instrument, which is used for the treatment of tissue in the presence of an electrically-conductive fluid medium, comprises an instrument shaft, and an electrode assembly at one end of the shaft. The electrode assembly comprises a tissue treatment electrode and a return electrode which is electrically insulated from the tissue treatment electrode by means of an insulation member. The tissue treatment electrode is exposed at the distal end portion of the instrument, and the return electrode has a fluid contact surface spaced proximally from the exposed end of the tissue treatment electrode by the insulation member. The exposed end of the tissue treatment electrode is constituted by a plurality of tissue treatment filamentary members made of an electrically-conductive material, the filamentary members being electrically connected to a common electrical supply conductor.

Abstract: In an electrosurgical instrument for the treatment of tissue in the presence of an electrically conductive fluid medium a bipolar electrode assembly has an active electrode with an exposed tissue treatment portion, a return electrode having an exposed fluid contact surface, and an insulating member positioned between and electrically insulating the active electrode in the return electrode. The insulating member serves to space apart the exposed active electrode treatment portion and the exposed fluid contact portion of the return electrode. The dimensions and configurations of the exposed portions of the electrodes and of the insulating member are such that when the electrode assembly is immersed in a conductive fluid medium, the ratio between the longest and shortest conduction path lengths between the active and return electrodes is less than or equal to 2:1. The invention also includes a combination of an electrosurgical instrument and a radio frequency generator.

Abstract: An electrosurgical instrument includes a housing and a first connector in the housing for receiving electrical energy. A shaft assembly is movably connected to the housing. The shaft assembly also includes at least one electrode at a distal end of the shaft assembly as well as at least one conductive portion for passing the electrical energy to the electrode. A spring is positioned between the shaft assembly and the housing for biasing the shaft assembly a distance away from the first connector. The distance defines a pre-determined gap between the first connector and the shaft assembly. The shaft assembly is proximally movable in the housing upon an application of force at the shaft assembly distal end for compressing the spring such that the conductive portion traverses the predetermined gap such that electrical energy is passed from the first connector to the electrode through the conductive portion.

Abstract: A coagulation instrument has a handle section and detachably connected thereto an electrode shank (4). Electrode conductors (5, 6) are led in the electrode shank from contact pick-off points (7, 8) situated in the direction of the handle to the operating end (9) of the electrode shank. In the region of the contact pick-off points staggered in the longitudinal direction of the electrode shank (4), directly adjacent to the respective internal conductors (5, 6), there is in each case an opening (15) in the insulating outer cover (11). In this region contact sleeves (13, 14) are arranged on the electrode shank and have a depression (16) penetrating the respective opening (15) for contacting the corresponding conductor (5) or (6).

Abstract: A safety-shielded trocar having an obturator with a linear cutting edge surface defining a base width substantially less than the diameter of the safety shield is disclosed. When the trocar is inserted through tissue, the tissue dilates from the width of the linear incision to accommodate the size of the safety shield of the trocar, thus making it possible to provide an access opening greater than the incisional width made by the linear cutting edge surface of the obturator. In a preferred embodiment, the safety shield has a shield tip region which is asymmetric to facilitate the dilation of the tissue as the trocar is inserted.

Abstract: A bipolar push rod assembly is disclosed in conjunction with an endoscopic bipolar cautery scissors instrument. The push rod assembly has two conductive push rods which are substantially covered and insulated from each other by a double lumen flexible sheath. The proximal ends of the push rods are stabilized by an overmolded plastic collar and the distal ends of the push rods are stabilized by a ceramic insulator. The plastic collar is provided with a snap retainer for coupling it to a plastic plug retainer having a pair of spaced apart passages. A pair of female plug adapters are press fit onto the proximal ends of the push rods and are maintained in place by the plug retainer with each adaptor residing in a respective one of the passages. The distal ends of the push rods are swaged approximately 90.degree. in opposite directions. A ceramic insulator is disclosed as a one-piece unit into which the distal ends of the push rods are inserted.

Abstract: A bipolar electrosurgical scissors for use in open or endoscopic surgery has a pair of opposed blade members pivotally joined to one another and to the distal end of the scissors itself by a rivet which extends through a insulated bushing member. Each of the blade members comprises a blade support and a blade itself, each fabricated from metal, such as stainless steel. The blades are affixed to their associated supports by means of a suitable adhesive or adhesive composite material such as a fiberglass reinforced epoxy exhibiting dielectric properties. Cutting is performed, steel-on-steel, without causing a short circuit between the two blade supports which themselves function as the bipolar electrodes.