Abstract: A plasma-generating device comprising an anode, a plurality of intermediate electrodes, an insulator sleeve, and a cathode is disclosed. The plurality of the intermediate electrodes and the anode form a plasma channel. One of the intermediate electrodes forms a plasma chamber. The cathode has a tapering portion that projects downstream the distal end of the insulator sleeve only partially. Also, the distal-most point of the cathode is located some distance away from the plasma channel inlet. Methods of surgical use of the plasma-generating device are also disclosed.

Abstract: A high frequency generator connected to an electrosurgical instrument comprising an electrical output terminal, a power source electrically connected to the output terminal, an arc detector, and a power control for controlling the electrical power delivered through the output terminal. The power control initially causes the delivery of a high output power for a phase for initial cutting support and thereafter, if ignition of an arc has occurred for a predetermined period of time to cause the delivery of reduced or no power and subsequently for a predetermined period of time to cause the delivery of reduced or no power at which no arc occurs, or if no ignition of an arc has occurred during the phase for initial cutting support, to cause the delivery of reduced or no power for a predetermined period of time of a short pause interval.

Abstract: An electrical conductor, such as a wire or catheter, which is coated circumferentially with a ferromagnetic material in a selected region, is fed from a high frequency alternating current source. The ferromagnetic material has a quick response in heating and cooling to the controllable power delivery. The ferromagnetic material can be used for separating tissue, coagulation, tissue destruction or achieving other desired tissue effects in numerous surgical procedures.

Abstract: An improved electrosurgical scalpel, with light emission, for generating electrical signals intended for applications to the body of a patient via an electrosurgical electrode is provided. An electrosurgical scalpel includes a handle with a receptacle portion of a conductive member for mounting and retaining an electrode blade, a light source with a power source encapsulated within the handle and a means to direct the light emitted outwardly towards the electrode tip. Operation of a switch on the handle to an on position serves to complete a circuit, activating the light source and, thereby directing light through an opening or upper portion and out from the first end of the handle towards the distal end of the electrode blade.

Abstract: The invention relates to a catheter, provided with an elongated body with an electrically conductive first end, wherein through said body at least one live wire extends which is connected to said first end and a channel for feeding a cooling fluid through said body, which channel is provided, in or near said first end, with at least one outlet opening and wherein, in said first end, a temperature sensor has been arranged, while said channel is thermally insulated from said first end.

Abstract: A hemostatic surgical blade is described which is formed of five symmetrically disposed layers. A martensitic stainless steel core is provided with oppositely disposed faces which are bonded to hard pure copper thermal transfer layers which, in turn, are supported by buttressing layers of austenitic stainless steel. The blade is heated by a blade heater circuit which is provided as a flexible circuit carrying one or more resistor heaters and associated leads supported by a polyimide substrate. A thermally conductive and electrically insulative adhesive is used to bond the flexible circuit to a blade blank. The system employs a multi-lead cable which is removable from an instrument handle. One blade embodiment involves an elongate stem for accessing body cavities and another embodiment incorporates a controller function within an instrument handle.

Abstract: A medical device system and method provide an RF electrosurgical generator coupled to an electrosurgical electrode via a patient box disposed in close proximity to the patient. An RF signal is delivered from the generator to the patient box where signal power is increased and the RF signal delivered to the electrosurgical electrode. The patient box is coupled to the electrosurgical electrode by a short cable capable of carrying an HV, high frequency 5 MHz signal without leakage. An electrical characteristic associated with the electrosurgical electrode is monitored and a desired RF power output and duty cycle maintained by adjusting DC input voltage applied to an RF amplifier, responsive to the monitoring. The system determines when the electrosurgical cutting electrode has started cutting and switches from a start mode to a run mode having a different RF duty cycle and a reduced RF power output controlled by a servo system.

Abstract: A method with apparatus for performing surgery using plasma is described. In one exemplary embodiment, the apparatus includes a radiofrequency signal generator, a conditioning network coupled to the radiofrequency signal generator, and a catheter coupled to the conditioning network, the catheter including at least one electrode, such that the conditioning network conditions radiofrequency energy produced by the radiofrequency signal generator to create plasma at the at least one electrode of the catheter. Such novel plasma ablation system provides the capability to create high precision ablation with minimal damage to adjacent structures in numerous types of matter while employing multiple operation platforms including catheter based plasma application.

Abstract: A medical device system and method provide an RF electrosurgical generator coupled to an electrosurgical electrode via a patient box disposed in close proximity to the patient. An RF signal is delivered from the generator to the patient box where signal power is increased and the RF signal delivered to the electrosurgical electrode. The patient box is coupled to the electrosurgical electrode by a short cable capable of carrying an HV, high frequency 5 MHz signal without leakage. An electrical characteristic associated with the electrosurgical electrode is monitored and a desired RF power output and duty cycle maintained by adjusting DC input voltage applied to an RF amplifier, responsive to the monitoring. The system determines when the electrosurgical cutting electrode has started cutting and switches from a start mode to a run mode having a different RF duty cycle and a reduced RF power output controlled by a servo system.

Abstract: Open electrosurgical forceps for sealing tissue are provided which include first and second shaft portions pivotably associated with one another. Each shaft portion has a jaw member disposed at a distal end thereof. Each of the jaw members includes an electrically conductive sealing surface adapted to communicate electrosurgical energy through tissue held therebetween and a slot formed through the sealing surface thereof. The forceps includes a cutting mechanism operatively associated with the first and second jaw members. The cutting mechanism includes a cutting element disposed within the slot of the at least one jaw member, the cutting element being movable from a first position wherein the cutting element is retracted within the at least one jaw member and a second position in which the cutting element at least partially projects from a sealing surface of the at least one jaw member.

Abstract: A surgical tool system including a laparoscopic surgical tool for heating, ablating, sealing, and/or dissecting tissue, a control system for monitoring impedance of the tissue during treatment thereof, and a tactile feedback system integrated onto a handle of the tool that generates relevant feedback from the control system in at least the form of haptic effects to the user. The tactile feedback alerts the tool user of changes in tissue properties, i.e., when the impedance of the tissue indicates that the treatment procedure is complete. In addition, the tactile feedback provided may supply information relating to the operating status of the control system to the user.

Abstract: An electrical ablation apparatus includes a housing extending along a longitudinal axis. A first electrode and a second electrode are disposed within the housing. The electrodes are configured to connect to electrically conductive wires. The first and second electrodes are separated by a gap. The second electrode includes first and second prongs defining an opening suitable to receive tissue to be ablated therebetween. When the first and second electrodes are energized at a predetermined energy level, an electric current suitable to ablate the tissue flows across the gap and forms an electric arc between the distal end of the first electrode and the tissue. A system includes an energy source to drive the electrical ablation apparatus. A method includes introducing the electrical ablation apparatus into a patient and ablating tissue with the electric arc.

Abstract: The present invention relates to a plasma-generating device, comprising an anode, a cathode and a plasma channel which in its longitudinal direction extends at least partly between said cathode and said anode. The end of the cathode which is directed to the anode has a cathode tip tapering towards the anode, a part of said cathode tip extending over a partial length of a plasma chamber connected to the plasma channel. The plasma chamber has a cross-sectional surface, transversely to the longitudinal direction of the plasma channel, which exceeds the cross-sectional surface, transversely to the longitudinal direction of the plasma channel, of an opening, positioned closest to the cathode, of the plasma channel. The invention also concerns a plasma surgical device and use of such a plasma surgical device.

Abstract: The present invention relates to a plasma-generating device comprising an anode, a cathode and an elongate plasma channel which extends substantially in the direction from said cathode to said anode. The plasma channel has a throttling portion which is arranged in said plasma channel between said cathode and an outlet opening arranged in said anode.

Abstract: A method for controlling an electrosurgical generator is contemplated by the present disclosure. The method includes applying an electrosurgical waveform to tissue through an electrode. The electrosurgical waveform includes one or more positive half-cycles one or more negative half-cycles. The method also includes measuring voltage and current of the electrosurgical waveform to detect a peak voltage of each of the positive half-cycles and the negative half-cycles and comparing the peak voltage of the half-cycles and the peak voltage of the negative half-cycles to determine generation of electrical discharges. The method further includes adjusting the current of the electrosurgical waveform to regulate the generation of the electrical discharges based on a comparison of the peak voltage of the positive half-cycles and the peak voltage of the negative half-cycles.

Abstract: An apparatus and method for performing surgery using plasma is described. In one exemplary embodiment, the apparatus includes a radiofrequency signal generator, a conditioning network coupled to the radiofrequency signal generator, and a catheter coupled to the conditioning network, the catheter including at least one electrode, such that the conditioning network conditions radiofrequency energy produced by the radiofrequency signal generator to create plasma at the at least one electrode of the catheter.

Abstract: A method and apparatus include determining a value of a parameter associated with operation of an electrosurgical probe having a particular probe design, and determining whether the value of the parameter is within a range of values that has been predetermined for the particular probe design to indicate that the probe is treating tissue in a desired manner. Power is delivered to the probe according to an algorithm based upon a determination that the value of the parameter is outside the range of values The algorithm delivers power in a pulsed profile including portions of low power and portions of high power. In one embodiment, the tissue treatment is ablation, the parameter is impedance, and the method limits tissue necrosis to less than 200 microns. In another embodiment, the tissue treatment is shrinkage, the parameter is temperature, and the method limits power delivery when the probe is not shrinking tissue.

Abstract: In a bipolar cutter for a living body tissue, a groove part is formed in a member that is arranged close to an active electrode, thereby providing a constitution to cut while the blood stanching is ensured since when a heat amount generated by the active electrode is conducted in the member, an excessive heat conduction to the member is efficiently interrupted by a layer of air that is produced due to the groove part and the living tissue is thus provided with more heat.

Abstract: A method and system are disclosed enabling configuration of a control system for an electrosurgical generator system for creating new surgical applications without changing the underlying software system. The system includes an outer loop controller for generating a control signal in accordance with at least a first subset of sensor data from at least one sensor; an inner loop controller for generating a setpoint control signal which is provided to an RF stage in accordance with at least the control signal generated by the outer loop controller and a second subset of sensor data from the at least one sensor; and a configuration controller for generating configuration data and providing first and second configuration data sets of the configuration data to the inner loop and outer loop controllers, respectively, for configuration thereof to provide a type of control selectable from a variety of types of control.

Abstract: A system and tool for performing a capsulotomy procedure. The system includes an air pressure unit, a capsulotomy and movement control unit providing electrical current and movement control, and a capsulotomy tool, and an extendable-retractable burning element coupled to the tool, and a slidable shaping element. A capsulotomy and movement control unit provides electrical current to the burning element and movement control for extending and retracting the burning element. When the burning element is in a flattened, retracted configuration, the tip of the tool can be inserted through a relatively small corneal incision. Then, the burning element is opened to a full circular, extended configuration, by pressing the shaping element against both joints of the bands, allowing a capsulotomy by applying an electrical pulse to the burning element.

Abstract: A catheter system for positioning an instrument within a body that includes a hub defining a lumen therethrough for passage of the instrument toward the body. The catheter system also includes an elongate tubular member defining a lumen therethrough. The lumen of the elongate tubular member is in communication with the lumen of the hub for further passage of the instrument toward the body. The system also includes a slitter member that is coupled to the hub. The slitter member is disposed to slit the elongate tubular member as the elongate tubular member moves relative to the hub.

Abstract: The invention relates to a variety of catheters provided with an elongate body with an electrically conductive first end. Wherein through said elongate body at least one conductive wire extends which is connected to an electrode. The electrode is coupled to said first end and an irrigation means (e.g. a channel, duct, tube, etc.) for feeding an irrigation fluid through said elongate body, where said irrigation means is provided, in, on, near, through, or adjacent said first end with at least one outlet opening, while said irrigation means is at least partially thermally insulated from said first end. Optionally a temperature sensor couples to the first end.

Abstract: A medical device system and method provide an RF electrosurgical generator coupled to an electrosurgical electrode via a patient box disposed in close proximity to the patient. An RF signal is delivered from the generator to the patient box where signal power is increased and the RF signal delivered to the electrosurgical electrode. The patient box is coupled to the electrosurgical electrode by a short cable capable of carrying an HV, high frequency 5 MHz signal without leakage. An electrical characteristic associated with the electrosurgical electrode is monitored and a desired RF power output and duty cycle maintained by adjusting DC input voltage applied to an RF amplifier, responsive to the monitoring. The system determines when the electrosurgical cutting electrode has started cutting and switches from a start mode to a run mode having a different RF duty cycle and a reduced RF power output controlled by a servo system.

Abstract: An electrosurgical high frequency (HF) generator for cutting and/or coagulating biological tissue. The generator comprises a power supply and a generator stage for exciting an HF oscillation signal in an output filter comprising a parallel resonant circuit coupled to a series resonant circuit, to which at least one electrode is connected. The generator has an improved efficiency level if the series resonant circuit has a resonance frequency that is higher than the resonance frequency of the parallel resonant circuit.

Abstract: In accordance with various embodiments, methods for controlling electrical power provided to tissue via a surgical device may comprise providing a drive signal. A power of the drive signal may be proportional to a power provided to the tissue via the surgical device. The methods may also comprise periodically receiving indications of an impedance of the tissue and applying a first composite power curve to the tissue, wherein applying the first composite power curve to the tissue comprises. Applying the first composite power curve to the tissue may comprise modulating a first predetermined number of first composite power curve pulses on the drive signal; and for each of the first composite power curve pulses, determining a pulse power and a pulse width according to a first function of the impedance of the tissue The methods may also comprise applying a second composite power curve to the tissue.

Abstract: The present invention provides for an apparatus and method to excise a tissue sample having a conducting element configured to receive power, an insulating holder coupled to said conducting element, and a connector coupled to said insulating holder for connection to a medical device.

Abstract: An electrosurgical system comprises a generator and an instrument including a first electrode, a second electrode, and an insulating spacer separating the first and second electrodes. The generator repeatedly measures a characteristic of the radio frequency output such as the impedance between the first and second electrodes. The generator analyses the impedance measurements, and interrupts the radio frequency signal when the rate of change of the impedance is such as to indicate the onset of a “flare-out”. In this way, the power is reduced before the flare-out leads to permanent damage or failure of the instrument.

Abstract: An battery-powered electrosurgical instrument includes a blade having a conductor edge portion and insulation layer with geometric shapes and composition that concentrate electrosurgical energy and reduce or eliminate the production of smoke and eschar and reduce tissue damage, thereby providing more efficient application of electrosurgical energy. The more efficient use of electrosurgical energy permits configuring the system to be battery-powered. The system may be portable or configured as a battery-backup powered system.

Abstract: A tip for a surgical handpiece having two coaxial tubes or channels mounted within a body. The tip has one or more features that shape the fluid discharge so as to optimize the performance of the handpiece for varying parts of the surgical procedure.

Abstract: A device for morcellating tissue within a body cavity of a patient comprises a stationary tube (8) having a distal end portion (12), and a bipolar electrosurgical electrode assembly (13) located at the distal end of the tube. The electrosurgical electrode assembly (13) comprises first and second electrodes (14, 16) separated by an insulating member (15), the bipolar electrosurgical electrode assembly extending around the circumference of the distal edge of the tube (8). When a pulsed electrosurgical cutting voltage is applied to the electrode assembly (13) and relative movement is initiated between the tube (8) and the tissue, a core of severed tissue is formed within the tube such that it can be removed from the body cavity of the patient. Temperature sensors (60) can be used to measure the temperature at the distal end of the tube (8), and to vary the duty cycle of the pulsed cutting voltage.

Abstract: This invention is an improved tissue-localizing device with an electrically energized locator element for fixedly yet removal marking a volume of tissue containing a suspect region for excision. The electrical energizing of the locator element facilitates the penetration of the locator element in to subject's tissue and minimizes resistance due to dense or calcified tissues. At least one locator element is deployed into tissue and assumes a predetermined curvilinear shape to define a tissue border containing a suspect tissue region along a path. Multiple locator elements may be deployed to further define the tissue volume along additional paths defining the tissue volume border that do not penetrate the volume. Delivery of electric cut-rent may be achieved through monopolar or bipolar electronic configuration depending on design needs. Various energy sources, e.g, radio frequency, microwave or ultrasound, may be implemented in this energized tissue-localizing device.

Abstract: The invention relates to a catheter, provided with an elongated body with an electrically conductive first end, wherein through said body at least one live wire extends which is connected to said first end and a channel for feeding a cooling fluid through said body, which channel is provided, in or near said first end, with at least one outlet opening and wherein, in said first end, a temperature sensor has been arranged, while said channel is thermally insulated from said first end.

Abstract: A device for resection and/or ablation of organic tissue by means of high-frequency current comprises, at the distal end, a loop that can be acted upon by high-frequency voltage and, in the proximal direction from the loop, at least one helix that can likewise be acted upon by high-frequency voltage, the arrangement of loop and helix being able to be moved in rotation about the longitudinal axis of the helix.

Abstract: This invention relates to a method of straddling an intraosseous nerve with an energy transmitting device to improve the therapeutic treatment of the nerve.

Abstract: A catheter and catheter system can use energy tailored for remodeling and/or removal of target material along a body lumen, often of atherosclerotic material of a blood vessel of a patient. An elongate flexible catheter body with a radially expandable structure may have a plurality of electrodes or other electrosurgical energy delivery surfaces to radially engage atherosclerotic material when the structure expands. An atherosclerotic material detector system may measure and/or characterize the atherosclerotic material and its location, optionally using impedance monitoring.

Abstract: An electrosurgical device is provided which can prevent the decrease of the effect of a treatment performed by an operator or the like on a biological tissue. A high-frequency voltage generated in an alternating power supply is transformed in a transformer. A high-frequency current in accordance with the transformed high-frequency voltage is supplied to the biological tissue via two high-frequency current supply lines. In this case, the impedance between the two high-frequency current supply lines is set in an impedance matching circuit so as to become maximum with respect to the frequency of the high-frequency current. Accordingly, the decrease of the effect of the treatment performed on the biological tissue can be prevented.

Abstract: An electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporizing tissue has an RF output stage (42) with an RF power bridge (Q1, Q2, Q3, Q4), a pair of output lines (74) and a series-resonant output network (48). The output impedance of the output stage (42) at the output lines (74) is less than 200/?P ohms, where P is the maximum continuous RF output power of the generator. The generator offers improved cutting and vaporizing performance, especially in relation to the reliability with which an arc can be struck when presented with an initial low impedance load. Overloading of the output stage is prevented by rapidly operating protection circuitry responsive to a predetermined electrical condition such as a substantial short-circuit across the output lines. In the preferred embodiment, the output stage is capable of maintaining output pulses at least 1 kW peak by supplying the power bridge from a large reservoir capacitor (60).

Abstract: The invention relates to a method of regulating the power available at the manipulator of an electronic scalpel so as to make said manipulator adapted to be used to obtain blood clotting, said electronic scalpel being of the kind comprising: at least a mains voltage rectifying circuit supplying rectified and direct voltage to at least a radio frequency circuit adapted to emit as output a current carrier signal at a main frequency set by an oscillator, said current signal feeding said manipulator through a radio frequency transformer, wherein said method consists in applying to the manipulator a wave form resulting from the sum of the carrier wave and a modulating wave of such frequency that the energy transmitted to the tissue to be coagulated is such to raise the temperature of the tissue to be coagulated until denaturation of the fibrinogen contained therein is caused and transforming it into fibrin.

Abstract: Tissue is treated using a radiofrequency power supply connected to an applicator having a chamber filled with an electrically non-conductive gas surrounded by a thin dielectric wall. A radiofrequency voltage is applied at a level sufficient to ionize the gas into a plasma and to capacitively couple the ionized plasma with the tissue to deliver radiofrequency current to ablate or otherwise treat the tissue.

Abstract: The subject invention utilizes the characteristics of in vivo tissue impedances to provide an embodiment of a retinal rake capable of providing a visible and/or preferably an audible signal to a surgeon that more clearly indicates which type of tissue(s) is in contact with the retinal rake. A preferred embodiment comprises a handheld, battery operated retinal rake having two electrodes, wherein at least one electrode is the modified retinal rake. Upon contact with different optical tissues, e.g., epiretinal membranes, retinal tissue, vitreous humor, etc., the electrodes detect varying impedances which are translated by onboard circuitry into various signals that indicate what type of tissue, fluid, structure, etc. is in contact with the retinal rake.

Abstract: An electrosurgical instrument for use by a surgeon that provides additional features and benefits compared with known designs. The operating mode as well as other operating parameters, especially power level, can be preset by the surgeon before commencing the procedure. Five operating modes are available using a three-button fingerswitch handpiece and a 3-way footswitch, including three unipolar modes and two bipolar modes over a full range of power levels including a new turbo mode for treating heavy bleeders.

Abstract: A method and device for incising tissue within the gastrointestinal tract is described. The device is an electrosurgical sphincterotome cutting device. The sphinctertome includes a pre-curved, heat set FEP distal tip. An electrically conductive cutting wire is positioned along the pre-curved distal tip. Manipulating a control handle tightens the cutting wire and incises and cauterizes target tissue. The curvature of the distal tip allows the sphincterotome to orient and steer itself towards a patient's sphincter as it emerges from an accessory channel of an endoscope.

Abstract: The invention relates to a high-frequency surgical apparatus in which, for the purpose of cutting and/or coagulating biological tissue by means of high-frequency current, a high-frequency generator having a first electrode and a second electrode forms a high-frequency circuit through the tissue being treated, with an electric arc being formed, said apparatus having a measuring device to detect DC voltage components forming in the high frequency circuit when the arc is formed, said DC voltage components being usable for controlling the high-frequency generator via a controlling device. The invention is characterized in that the measuring device has an arc-decoupling circuit which separates the DC voltage components in the positive half-cycle of the high-frequency AC voltage from the DC voltage components in the negative half-cycle of the high-frequency AC voltage and makes available at least one of the separated DC voltage components as a signal for subsequent processing in the controlling device.

Abstract: A device and system for removing tissue such as polyps is provided and includes a tubular member having proximal and distal ends, a snare portion operably extending from within the distal end of the tubular member and including first and second electrodes configured to treat tissue therebetween, the snare portion further including a cutting member for severing the treated tissue. The tissue removal device may further include a handle portion operatively extending from within the proximal end of the tubular member. The handle portion may be configured for operable engagement by a user and the cutting member may extend between distal ends of the first and second electrodes.

Abstract: A method and apparatus include determining a value of a parameter associated with operation of an electrosurgical probe having a particular probe design, and determining whether the value of the parameter is within a range of values that has been predetermined for the particular probe design to indicate that the probe is treating tissue in a desired manner. Power is delivered to the probe according to an algorithm based upon a determination that the value of the parameter is outside the range of values The algorithm delivers power in a pulsed profile including portions of low power and portions of high power. In one embodiment, the tissue treatment is ablation, the parameter is impedance, and the method limits tissue necrosis to less than 200 microns. In another embodiment, the tissue treatment is shrinkage, the parameter is temperature, and the method limits power delivery when the probe is not shrinking tissue.

Abstract: An electrosurgical electrode capable of vaporization, coagulation, desiccation or cutting of tissue is disclosed. The probe has a first portion configured for tissue vaporization, and a second portion configured for tissue desiccation or coagulation. Simultaneous vaporization and desiccation may be achieved, the balance between the effects being controlled by the orientation and motions of the electrode. The electrode may have irrigation and aspiration means.

Abstract: A surgical jaw assembly having a top portion and a bottom portion hingedly attached. The top and bottom portion having a base, a seal plate and a cover, the seal plate and base being in direct contact and being electrically common. The bottom portion having a blade that is stationary relative to the base and the top portion having an insert configured to receive the blade when the top portion and bottom portion are in a predetermined position. The cover is overmolded onto the base, securing the seal plate to the base on both the top portion and bottom portion.

Abstract: A method and apparatus for minimally invasive total joint replacement is disclosed. The method involves sculpting the articular surface of a second bone that normally articulates with a first bone by attaching or supporting a bone sculpting tool directly or indirectly to the first bone with the tool in sculpting engagement with the articular surface of the second bone, and then sculpting the articular surface of the second bone with the joint reduced. The reamer system includes a reamer drive, a grater, a handle and a femoral broach.

Abstract: Methods and apparatus are provided for selective surgical removal of tissue. In one variation, tissue may be ablated, resected, removed, or otherwise remodeled by standard small endoscopic tools delivered into the epidural space through an epidural needle. The sharp tip of the needle in the epidural space, can be converted to a blunt tipped instrument for further safe advancement. The current invention includes specific tools that enable safe tissue modification in the epidural space, including a barrier that separates the area where tissue modification will take place from adjacent vulnerable neural and vascular structures. A nerve stimulator may be provided to reduce a risk of inadvertent neural abrasion.

Abstract: An ultrasonic clamp coagulator assembly that is configured to permit selective cutting, coagulation and clamping of tissue during surgical procedures. An elongated portion of the instrument can be configured for endoscopic applications and has an outside diameter of less than 6 mm. The construction includes a clamping mechanism, including a clamp arm pivotally mounted at the distal portion of the instrument, which is specifically configured to create a desired level of tissue clamping forces, exceeding 4 pounds when the trigger is fully closed. The clamping mechanism includes a two-piece pad design and pad material that enables the higher tissue clamping forces and a force-limiting mechanism that effectively smooths out abusive tissue forces. The assembly also features hand activation configured to provide an ergonomical grip and operation for the surgeon. Hand switches are placed in the range of the natural swing of the surgeon's thumb, whether gripping the surgical instrument right-handed or left handed.