Abstract: A surgical instrument comprising a handle and an elongated probe connected to the handle. The elongated probe has a terminus distal to the handle. At least one electrode that includes an electrode surface is positioned on the terminus so that a line from a geometric center of the electrode surface and substantially perpendicular to the electrode surface intersects at an angle a longitudinal axis formed by the elongated probe. A conductor is provided for attaching the at least one electrode to the handle.

Abstract: An electrosurgicalscissors for an endoscopic mucosal resection includes an flexible inserting portion that is to be inserted into a body cavity through an endoscope and first and second electrodes mounted to the distal end of the inserting portion so as to be movable between an open position and a closed position. The first and second electrodes are connected with conductive wires to be provided with high frequency voltage. Each of said first and second electrodes as a contact surface formed in a substantially straight shape. The first and second electrodes come into contact with each other at the contact surfaces when moved to the closed position and the contact surfaces are spaced apart from each other when the first and second electrodes are moved to the open position.

Abstract: An endoscopic forceps instrument has an inserting portion to be inserted into a body cavity through an endoscope, a clevis, a pair of rivets, and a pair of opposing jaws. The clevis is coupled to a distal end of the inserting portion. The pair of rivets is coupled to the clevis. Each of the rivets has a tip end that is swaged in order to fix the rivet to the clevis. The pair of opposing jaws is pivotably coupled to respective rivets so as to be movable between an open position and a closed position. The pair of rivets is arranged in parallel to each other. Further, the pair of rivets is arranged such that the tip ends thereof, which are swaged and therefore having relatively low mechanical strength, are located and swaged at opposite sides of the clevis.

Abstract: An RF tonsillar probe comprises a generally elongated insulated structure having means for coupling to the bipolar outlet of electrosurgical apparatus, and two internal insulated wires leading to a distal end that is angled downwardly and that terminates in two laterally-spaced needle electrodes whose tips are exposed. The probe works best with relatively high-frequency RF electrosurgical currents in excess of 1.5 MHz. The combination of the bipolar mode with electrosurgical currents in the MHz range causes relatively low tissue temperatures avoiding the need for the addition of a complicated temperature-controller structure and suitable circuitry, and the bipolar action confines the RFTA effect to the tissue region between the two active needle electrodes.

Abstract: According to the present invention, a heat generating element to be current-carried is provided at a grasp portion on the tip side of a treatment portion, the patient's body tissue grasped between a pair of grasp portions is coagulated by heat of the heat generating element, and a metal scissors blade for cutting the patient's body tissue is provided on the rear side of the grasp portion in the treatment portion.

Abstract: A bipolar endoscopic instrument including a tubular stem having a distal end and a proximal end. The stem distal end supports two jaws that are pivotable relative to one another. The proximal end of the tubular stem has a bipolar hf plug inserted therein at an acute angle to a push/pull wire. The plug applies a bipolar output of a high-frequency (hf) voltage source into the inside of the instrument. The inserted end of the hf plug is shaped such that the plug contacts are axially insulated from each other and each plug contact touches an electrically conducting contact element inside the instrument which, in turn, is connected in electrically conducting manner to one of the two jaws. A unit is present inside the instrument and includes the two contact elements and an insulator electrically separating the contact elements. The hf plug engages the insulator while a particular plug contact touches a particular contact element.

Abstract: A surgical device for severing tissue, the surgical device comprising; a first shaft having a first internal lumen and a first slot disposed at a distal end; a clamp slidingly disposed in the first slot between open and closed positions to capture tissue in the first slot, the clamp having a clamping surface disposed at a distal end; at least one electrode for applying RF energy to the tissue captured in the first slot; a cutting blade slidingly disposed in the first slot between open and closed positions, the cutting blade having a cutting edge to sever the tissue; first actuation means for actuating the clamp between the open and closed positions; and second actuation means for actuating the cutting blade between the open and closed positions.

Abstract: An endoscopic implement including two electrodes connected to the terminals of a high frequency generator and mounted to a distal end of an elongated insertion element. An insulator is disposed between and secured to the two electrodes. One of the electrodes is mounted to a lateral surface of the insulator at a location that is laterally spaced from an axis of the insertion element. The other electrode is mounted at a distal end of the insulator.

Abstract: The invention is directed to an electrosurgical device having a shapeable elongate cutting electrode having a free distal end with an exposed length of at least about 0.25 inch and secured by its proximal end to the distal end of a handle. The electrosurgical device is designed for use with a high frequency electrosurgical generator which has an output at a frequence of between about 1 MHz and about 10 MHz, preferably about 3 to about 8 MHz. Preferably, the output has an essentially sinusoidal waveform with little harmonic distortion. The methods provide for the enhanced cutting of a variety of tissue including muscular, connective, glandular and fatty tissue. The device is particularly suitable in performing a breast biopsy.

Abstract: An electrosurgical instrument for use in cutting and/or coagulating tissue includes one or more electrode surfaces coated with a material having a positive temperature coefficient of impedance. The PTC coating acts to control the temperature of the electrodes and to reduce the incidence of tissue becoming adhered to the electrode surface. Examples of electrosurgical instruments employing such coated electrodes include forceps, scissors or scalpel blade instruments.

Abstract: An electrosurgical cutting blade (1) comprises a first electrode (2), a second electrode (3), and an electrical insulator (4) separating the first and second electrodes. The first and second electrodes have dissimilar characteristics (cross-sectional area, thermal conductivity etc.) such that the first electrode (2) is encouraged to become an active electrode and the second electrode (3) is encouraged to become a return electrode. The spacing between the first and second electrodes (between 0.25 mm and 3.0 mm) and the peak voltage supplied to the electrodes (2 and 3) are both selected such that arcing does not occur directly between the electrodes, but between the first electrode and the tissue at the target site. The arrangement is such that, in use, a thermal differential of at least 50° C. is established between the first and second electrodes (2 and 3), such that the second electrode is maintained below a temperature of 70° C.

Abstract: Electrosurgical methods and apparatus for removing tissue from a target site of a patient. An electrosurgical suction apparatus includes an aspiration channel in communication with a distal aspiration port, and an electrode support having a plurality of active electrodes disposed thereon, the plurality of active electrodes spanning the aspiration port. Each of the plurality of active electrodes is adapted for removing tissue from a target site to form low molecular weight ablation by-products. Each of the plurality of active electrodes is also adapted for digesting resected tissue fragments to yield low molecular weight ablation by-products. Ablation by-products and resected tissue fragments are readily removed from the target site via an aspiration stream flowing proximally through the aspiration channel.

Abstract: A method and apparatus for transmural ablation using an instrument containing two electrodes or cryogenic probes. A clamping force is exerted on the two electrodes or probes such that the tissue of the hollow organ is clamped therebetween. Bipolar RF energy is then applied between the two electrodes, or the probes are cryogenically cooled, thus ablating the tissue therebetween. A monitoring device measures a suitable parameter, such as impedance or temperature, and indicates when the tissue between the electrodes has been fully ablated.

Abstract: A bipolar surgical device comprises 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: An electrosurgical cutting blade (1) comprises a first electrode (2), a second electrode (3), and an electrical insulator (4) separating the first and second electrodes. The first and second electrodes (2 and 3) have dissimilar characteristics (cross-sectional area, thermal conductivity etc.) such that the first electrode (2) is encouraged to become an active electrode and the second electrode (3) is encouraged to become a return electrode. The spacing between the first and second electrodes (between 0.25 mm and 3.0 mm) and the peak voltage supplied to the electrodes are both selected such that arcing does not occur directly between the electrodes, but between the first electrode and the tissue at the target site. The arrangement is such that, in use, a thermal differential of at least 50° C. is established between the first and second electrodes, such that the second electrode is maintained below a temperature of 70° C.

Abstract: A endoscopic bipolar forceps for clamping and sealing tissue includes first and second jaw members pivotally attached in opposing relation relative to one another which are movable from a first 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. A drive rod assembly connects each of the jaw members to a source of electrical energy such that the jaw members are capable of conducting bipolar energy through the tissue held therebetween. A handle attached to the drive rod assembly imparts movement of the first and second jaw members from the first and second positions. At least one stop member is attached to the jaw members for controlling the distance between the jaw members. The forceps may also include a yoke member for insulating the jaw members from one another to prevent short circuiting of the forceps.

Abstract: The invention relates to a surgical tool with an electricity supply provided from an electrosurgical generator. The apparatus includes an active or feed electrode and at least one return electrode, with the electrical supply controlled in order to allow and control the operations of the electrodes at any instant to operate in the predetermined active or return modes. This control is achieved by monitoring the dynamic feedback from the tool and altering the electrical output to maintain the active and return electrode conditions.

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 both ends 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. The electrosurgical device has an electrode and a heat pipe to conduct heat from the electrodes where substantially all heat conducted from the electrode through the heat pipe is dissipated along the length of the heat pipe. The heat pipe can have a thermal time constant less than 60 seconds and preferably less than 30 seconds.

Abstract: A removable electrode assembly for use in combination with a forceps having opposing end effectors and a handle for effecting movement of the end effectors relative to one another. The electrode assembly includes a housing which is removably engageable with the forceps and a pair of electrodes which are attachable to a distal end of the housing. The electrodes are removably engageable with the end effectors of the forceps such that the electrodes reside in opposing relation relative to one another. The electrode assembly also includes a cover plate which is removably attachable to the housing and at least one stop member for controlling the distance the electrodes move relative to one another.

Abstract: An instrument for high-frequency treatment is provided which includes a first jaw having, on a first holding surface thereof, an active electrode provided with a substantially flat portion and a protruded portion, and a second jaw having an opposing electrode formed on a second holding surface opposed to the first holding surface. The opposing electrode includes a portion opposed to the protruded portion of the active electrode, and the opposing portion has a shape different from that of the protruded portion of the active electrode. The instrument also includes an operation member for opening and closing the first jaw and the second jaw.

Abstract: A bipolar electrosurgical instrument that is configured for use in MIS and other electrosurgical procedures. The instrument is constructed as a bipolar electrode comprising a bare wire as the active electrode spaced from a window below which is the return electrode. The bare wire electrode preferably is configured as a straight wire projecting laterally from the distal end or with straight or curved sections that extend rearwardly toward the window. When energized, a bipolar discharge is generated between the active and return electrodes.

Abstract: A self-cooling electrode for use with an ablation catheter has greater surface area that allows electrode to dissipate heat to the blood pool more effectively and increased thermal mass, and, therefor greater heating capacity/thermal conductivity for improved heat transfer between the electrode and tissue for more effective tissue heating. The electrode design allows increased power to be delivered with minimized risk of overheating or coagulation at the tissue-electrode interface. The increased thermal mass and thermal conductivity of the electrode design are achieved with a substantially solid electrode body with thick walls. Cooling and increased heat exchange are achieved with an alternating pattern of channels and projections that collectively define a plurality of edges either parallel or perpendicular to the electrode axis.

Abstract: The present invention provides systems, apparatus and methods for selectively applying electrical energy to body tissue in order to ablate, contract, coagulate, or otherwise modify a target tissue or organ of a patients. An electrosurgical apparatus of the invention includes a shaft having a shaft distal end bearing an active electrode and a return electrode. At least one of the active electrode and the return electrode is moveable such that the shaft distal end can adopt a closed configuration or an open configuration. The apparatus can operate in an ablation mode or a sub-ablation mode. The closed configuration is adapted for clamping and coagulating a target tissue while the apparatus is operating in the sub-ablation mode, while the open configuration is adapted for ablating the target tissue via molecular dissociation of tissue components. A method of the present invention comprises clamping a target tissue or organ with an electrosurgical probe.

Abstract: An electrosurgical instrument is provided for the treatment of tissue in the presence of an electrically-conductive fluid medium. The instrument comprises an instrument shaft (10), a tissue treatment electrode (12) at one end of the shaft, and removal means, the instrument having an apertured portion (20a) through which matter can be aspirated by the removal means from the region surrounding the tissue treatment electrode. The removal means comprises a channel formed within the instrument shaft (10) and leading from the apertured portion (20a). The channel is provided with agitation means (14) for preventing the build-up of sublimation products within the channel.

Abstract: An electrosurgical instrument is provided for the treatment of tissue in the presence of an electrically-conductive fluid medium. The instrument comprises an instrument shaft (10), and a tissue treatment electrode (12) at the distal end of the shaft for electrosurgically excising tissue pieces at an operation site. The tissue treatment electrode (12) is cyclically movable relative to the distal end of the shaft (10). Threshold control means are provided for controlling the power threshold for vaporisation of the electrically-conductive fluid medium at the tissue treatment electrode (12).

Abstract: The present invention provides systems, apparatus and methods for selectively applying electrical energy to body tissue in order to incise, dissect, harvest or transect tissues or an organ of a patient. The electrosurgical systems and methods are useful, inter alia, for accessing, dissecting, and transecting a graft blood vessel, such as the internal mammary arteries (IMA) or the saphenous vein, for use in a by-pass procedure. A method of the present invention comprises positioning an electrosurgical probe adjacent the target tissue so that one or more active electrode(s) are brought into at least partial contact or close proximity with a target site in the presence of an electrically conductive fluid. A high frequency voltage is then applied between the active electrode and one or more return electrode(s). During application of the high frequency voltage, the electrosurgical probe may be translated, reciprocated, or otherwise manipulated such that the active electrode is moved with respect to the tissue.

Abstract: The invention provides a medical device that includes a housing, a tubular member extending from the distal end of the housing, a first arm extending from the distal end of the tubular member, the first arm including a first electrode, a second arm extending from the distal end of the tubular member, the second arm including a second electrode and being disposed coaxially with the first arm, at least one solution infusion opening on each electrode, and a solution delivery channel for delivery of a conductive solution to the solution infusion openings. According to the invention, at least one of the first arm or the second arm is translationally moveable, and at least one of the first arm or the second arm is adapted to be coupled to a source of radiofrequency energy. The invention also provides a corresponding method for treating blood vessels or other tissues of the body.

Abstract: In order to improve the cutting properties of surgical bipolar scissors with two scissor blades pivotable relative to each other, the first of which consists of an electrically conductive material and the second of an electrically insulating material on the side thereof facing the first scissor blade, but of an electrically conductive material on the side facing away from the first scissor blade, it is proposed that the second scissor blade comprise a ceramic shaped body in the form of a complete scissor blade which extends beyond a bearing point of the two scissor blades, that a metallic support blade which similarly extends beyond the bearing point rest against the outer side of the shaped body over the surface thereof, and that the shaped body and the support blade be permanently connected to each other at their contact surface.

Abstract: An electrosurgical device has an electrode and a heat pipe to conduct heat from the electrodes where substantially all heat conducted from the electrode through the heat pipe is dissipated along the length of the heat pipe. The heat pipe can have a thermal time constant less than 60 seconds and preferably less than 30 seconds.

Abstract: An electrosurgical instrument having a working end that utilizes a coagulation surface and a cutting surface that can be moved relative to each other and wherein only one of the two surfaces is electrically enabled depending on their relative positions. The user can then depress a switch to activate the electrically enabled surface.

Abstract: An electrosurgical system includes a generator (10) for generating radio frequency power, and an electrosurgical instrument (12) including at least three electrodes. The generator comprises a radio frequency output stage having at least a pair of output lines (60C), and a power supply (66) coupled to the output stage for supplying power to the output stage. The generator also includes a controller (72) capable of varying a radio frequency signal supplied to the output lines, and a switching circuit (62) having three or more output connections (62A, 62B, 62C) each electrically connected with a respective one of the at least three electrodes. This switching circuit is operable to vary the connections between the output lines (60C) and the output connections (62A, 62B, 62C).

Abstract: In a treating apparatus, a forceps body as a treating device is connected to a generator as a control device. The forceps body mainly includes a pair of handle portions, which are used for manipulation by being held by an operator, a pair of jaws provided between the handle portion and the pair of jaws, which are used to coagulate/resect by grasping living-body tissue to be treated and a pair of scissors component members. A heating member, which is a heat generating source as a heat generating portion for applying heat energy to living-body tissue, is embedded at least one of the jaws. A pair of electrode portions, which is a treating energy generator, is provided to the pair of jaws. By supplying bipolar electric surgical knife current between the pair of electrode portions, high frequency current as treating energy is applied to the grasped living-body tissue.

Abstract: An electrosurgical working end and method for transecting an anatomic structure along a targeted line and for creating a thermal welds along either of both transected tissue margins, for example for use in a partial lung resection procedure. In one embodiment, the working end provides elongate curved or linear guide members that can be positioned on opposing sides of the targeted anatomic structure. The working end carries a slidable member with interior channels that receive the guide or jaw members. The electrode or electrodes carried by of working end define a resistive gradient for creating controlled Rf ohmic heating in the engaged tissue.

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. The present invention includes a channeling technique in which small holes or channels are formed within tissue structures in the mouth, such as the tonsils, tongue, palate and uvula, and thermal energy is applied to the tissue surface immediately surrounding these holes or channels to cause thermal damage to the tissue surface, thereby stiffening the surrounding tissue structure. Applicant has discovered that such stiffening of certain tissue structures in the mouth and throat helps to prevent the tissue structure from obstructing the patient's upper airway during sleep.

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 both ends 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. The electrosurgical device has an electrode and a heat pipe to conduct heat from the electrodes where substantially all heat conducted from the electrode through the heat pipe is dissipated along the length of the heat pipe. The heat pipe can have a thermal time constant less than 60 seconds and preferably less than 30 seconds.

Abstract: The invention provides a device and method for reducing or segmenting a large tissue mass in a body cavity during a minimally invasive surgery. This is accomplished with using a device that uses both mechanical and electro-surgical mechanisms by creating an electrical path between two electrodes through the tissue mass. The invention uses an isolation bag to insulate the electrical path created from the body cavity.

Abstract: An electrosurgical working end and method for transecting an anatomic structure along a targeted line and for creating a thermal welds along either of both transected tissue margins, for example for use in a partial lung resection procedure. The working end provides elongate curved or linear guide-track members that can be positioned on opposing sides of the targeted anatomic structure. The working end carries a slidable member with interior channels that receive the guide-track members. The extension member can be moved from a proximal position to an advanced distal position by advancing over the guide-track members. As the extension member advances over the guide-track members (i) the tracks compress the tissue just ahead of the advancing extension member to allow the laterally-outward portion of the extension member to ramp over the tissue, (ii) while contemporaneously a cutting element at the distal end of the extension member transects the tissue.

Abstract: A surgical device including: a first shaft having a first projection radially offset from an axial direction of the first shaft, the first projection having a first clamping surface; a second shaft slidably disposed relative to the first shaft, the second shaft having a second projection radially offset from the axial direction, the second projection having a second clamping surface; a dissector for dissecting tissue from a blood vessel to be harvested; a first actuator for sliding the second projection relative to the first projection to capture a side branch of the vessel between the first and second clamping surfaces; at least one electrode for applying cauterizing energy to cauterize the captured side branch; a cutting blade movably disposed on one of the first or second projections; and a second actuator for moving the cutting blade to sever the side branch captured between the first and second projections.

Abstract: A bipolar electrosurgical hook probe includes an end effector that includes first and second electrodes placed in parallel, closely-spaced relationship, each being of a relatively large surface area and a conductive reciprocally movable hook member that is movable into and out of a space between the first and second electrodes. A switch mechanism is provided by which an RF current can alternatively be made to flow between the first and second electrodes during electrocoagulation and from the hook electrode to each of the first and second electrodes when the instrument is operating in its cut mode.

Abstract: A bipolar medical instrument is provided for cutting tissue. The instrument comprises a first working element and at least one second working element, which are arranged adjacent to one another at a distal end of the instrument. The first working element and the second working element are configured as an electrode connectable to high frequency current and a counter electrode. One of the first working element and the second working element comprises at least one projection, which is directed toward the other working element. The free end of the projection is configured such that a concentration of the current density occurs at the free end.

Abstract: A system and method for treating skin. The system comprises a source of radiation for irradiating the skin and a pair of electrodes for applying a voltage to the skin. An electrical meter measures an electrical response of the skin to the applied voltage. A processor adjusts a parameter of the radiation based upon the measured response. The invention may be used to control skin temperature during thermal treatment.

Abstract: Method, system and apparatus for carrying out accurate electrosurgical cutting. A thin resilient electrode is utilized at the forward end region of an instrument which is deployable from a longitudinally disposed slot positioned rearwardly of the tip of the instrument. Lateral sides of the slot extend between a forward location adjacent the tip and a rearward location. The electrode is deployed by urging it forwardly in compression to form an arch profile supported by the abutting slot sides adjacent the forward and rearward locations. Electrosurgically excitable with a cutting output, the electrode may carry out a cutting action both during its deployment and retraction into the noted slot. This permits a pivoting maneuver effective for circumscribing a volume of targeted tissue.

Abstract: A suction assisted ablation device having a support surface, suction elements disposed adjacent the support surface, at least one electrode and at least one suction conduit is provided. The device may further include fluid openings, which allow fluid to irrigate target tissue and aid in ablation. A method for ablating tissue using suction is also provided.

Abstract: A bipolar surgical device comprises 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: Device for delivering radio frequency (RF) energy, for example during tissue ablation procedures, comprising an electrode having a distal end associated with tissue puncturing means and a proximal end connectable to a radio frequency energy source, wetting means for wetting the proximity of the distal end of the electrode with a non-toxic (RF) conductive solution and cooling means for cooling at least the distal end of the electrode. The invention further relates to a process for cooling and wetting a radio frequency energy delivering device and to a guidance element therefor.

Abstract: An endoscopic bipolar forceps includes an elongated shaft having opposing jaw members at a distal end thereof. The jaw members are movable relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween. The forceps also includes a source of electrical energy connected to each jaw member such that the jaw members are capable of conducting energy through tissue held therebetween to effect a seal. A generally tube-like cutter is included which is slidably engaged about the elongated shaft and which is selectively movable about the elongated shaft to engage and cut tissue on at least one side of the jaw members while the tissue is engaged between jaw members.

Abstract: A laparoscopic bipolar electrosurgical instrument for sealing tissue includes a handle having an elongated tube affixed thereto. The tube includes first and second jaw members having electrically conductive sealing surfaces attached to a distal end thereof which are movable from a first position for approximating tissue to a second position for grasping tissue therebetween. The handle includes a fixed handle and a handle which is movable relative to the fixed handle to effect movement of the jaw members from the first position to the second position for grasping tissue. The jaw members connect to a source of electrosurgical energy such that the opposable sealing surfaces are capable of conducting electrosurgical energy through tissue held therebetween. A stop is included for maintaining a minimum separation distance between opposing sealing surfaces. A ratchet is also included to maintain a closure force in the range of about 7 kg/cm2 to about 13 kg/cm2 between opposing sealing surfaces.

Abstract: Electrosurgical apparatus and methods for ablating, coagulating, shrinking, stiffening, or other treatment of a target tissue of a patient. An apparatus of the invention includes an electrosurgical probe, and an introducer needle adapted for passing the distal end of the probe therethrough, wherein the probe includes an uninsulated shaft which makes electrical contact with the introducer needle when the shaft is engaged within a lumen of the introducer needle. The apparatus further includes an active electrode and a return electrode, wherein the return electrode comprises the shaft in combination with the introducer needle. In one embodiment, the active electrode includes an expandable electrode head.

Abstract: An electrosurgical probe is provided to vaporize, cut, coagulate or remove tissue from a body structure. A method of surgically treating a mammal includes providing a surgical instrument including a length of shaft and an active electrode having a curved current density edge with at least one convex surface; and ablating a tissue surface with said surgical instrument.

Abstract: An electrosurgical device has an electrode and a heat pipe to conduct heat from the electrodes where substantially all heat conducted from the electrode through the heat pipe is dissipated along the length of the heat pipe. The heat pipe can have a thermal time constant less than 60 seconds and preferably less than 30 seconds.