Abstract: A system and method for performing electrosurgical procedures are disclosed. The system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue in form of one or more electrosurgical waveforms having a crest factor and a duty cycle. The system also includes sensor circuitry adapted to measure impedance and to obtain one or more measured impedance signals. The sensor circuitry is further adapted to generate one or more arc detection signals upon detecting an arcing condition§. The system further includes a controller adapted to generate one or more target control signals as a function of the measured impedance signals and to adjust output of the electrosurgical generator based on the arc detection signal. An electrosurgical instrument is also included having one or more active electrodes adapted to apply electrosurgical energy to tissue.

Abstract: An electrosurgical system and method are disclosed. The system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The generator includes sensor circuitry adapted to continuously monitor tissue impedance to generate a variance impedance curve and a microprocessor adapted to calculate a slope of a segment of the variance impedance curve. The microprocessor also calculates a bubble factor that represents the rate of formation and absorption of bubbles within tissue to determine minimum tissue impedance and maximum tissue conductance. The system further includes an electrosurgical instrument which includes one or more active electrodes adapted to apply electrosurgical energy to tissue.

Abstract: An electrosurgical pencil configured and adapted to support an electrocautery blade. A strain gauge is affixed to the proximal end of the electrocautery blade and measures the displacement of the blade as a result of resistance and drag acting on the blade. The electrosurgical pencil also includes a meter electrically connected to the strain gauge for monitoring either a change in voltage, a change in electrical current or a change in optical wavelength. The amount of blade displacement as measured by the strain gauge is available for display to the surgeon and/or as sensory input for a control circuit in the electrosurgical generator that modulates the generator output waveform. The electrosurgical pencil further includes a control circuit electrically coupled between the electrocautery blade and the electrosurgical generator. The control circuit is configured and adapted to control power supplied to electrocautery blade based on the displacement measured by the strain gauge.

Abstract: The invention concerns a high frequency generator for the connection of an electrosurgical instrument comprising an electrical output terminal for an electrosurgical instrument, a current or voltage source connected at least indirectly to the output terminal, an arc detector, and a power control for controlling the electrical power delivered by way of the output terminal, wherein the power control is adapted firstly to cause the delivery of a high output power for a phase for the initial cutting support and subsequently thereto either if ignition of an arc has occurred during the phase for initial cutting support for a predetermined period of time of a cutting phase to cause the delivery of a power which is reduced in relation to the high power and subsequently for a predetermined period of time of a long pause interval to cause the delivery of no power or a lower 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 no pow

Abstract: A surgical operation apparatus includes a handpiece to be held by an operator, and an apparatus main body to be connected with the handpiece, wherein the handpiece includes a high-frequency treatment unit to treat a living tissue by a high-frequency current, an ultrasonic treatment unit to treat a living tissue by an ultrasonic vibration, and a sensor unit to perform detection for calculation of an impedance of a living tissue, and the apparatus main body includes a high-frequency output module to activate the high-frequency treatment unit, an ultrasonic output module to activate the ultrasonic treatment unit, a sensor module to calculate the impedance of the living tissue based on a detection result obtained from the sensor unit, and a control module to automatically control at least the ultrasonic output module of the high-frequency output module and the ultrasonic output module in accordance with the impedance calculated by the sensor module so as to automatically adjust an output of at least the ultrasoni

Abstract: An apparatus and method for stopping of ablation energy delivery to tissues during cardiac ablation procedures provides added safety. The apparatus uses control switch mechanism comprising relay switch and circuitry inserted between the ground patch and ablation generator. Alternatively, the control switching means can be on the catheter side of the ablation circuit. The switching mechanism is connected to a computer, which controls the on-off switch based on pre-determined conditions. When the control switch part of the circuit is opened, the ablation generator shuts of immediately. The software in the computer is configured, such that the computer controlled stopping of energy delivery only occurs when patient safety is at risk.

Abstract: Methods and apparatus for delivering, monitoring, balancing, and/or dispersing high-frequency current flow in monopolar electrosurgery. The methods generally include positioning an active electrode in or on target tissue, positioning at least two dispersive electrodes on tissue remote from the target tissue, establishing electrical current flow from the active electrode through the dispersive electrodes, and individually adjusting the current through at least one of the dispersive electrodes to balance the current through the dispersive electrodes. By adjusting and balancing the current through two or more dispersive electrodes, safety of electrosurgical systems may be enhanced by preventing unwanted patient burns.

Abstract: An electrosurgical generator is disclosed. The generator includes a radio frequency output stage configured to generate a radio frequency waveform and a sensor circuit configured to measure a property of the radio frequency waveform during a predetermined sampling period to determine whether an arc event has occurred. The generator also includes a controller configured to determine a total charge and/or total energy deposited by the radio frequency waveform during the predetermined sampling period associated with the arc event. The controller is further configured to adjust the output of the electrosurgical generator based on at least one parameter to limit arcing.

Abstract: Electrosurgical tissue specimen recovery apparatus and system employing a multi-leaf capture component configured with pursing cables which are electrosurgically excited to define a cutting leading edge. To complete a capture, the cables are loaded in tension to purse and thus converge the tips of the capture component leafs together. The forward regions of the leafs are configured with a combination of a thin flat stainless steel region over which a polymeric cable guide is positioned. The polymeric cable guide and stainless steel leaf driving combination improves frictional aspects as well as the resulting aspect ratio of a recovered tissue specimen.

Abstract: A device is disclosed for locating and treating an infarct scar in a heart. The device includes a catheter, a collapsible heater and energizing means connected to the collapsible heater for energizing the collapsible heater to raise the temperature of the infarct scar to a temperature sufficient to reduce the surface area of the infarct scar.

Abstract: An electrosurgical generator has an output power control system that causes the impedance of tissue to rise and fall in a cyclic pattern until the tissue is desiccated. The advantage of the power control system is that thermal spread and charring are reduced. In addition, the power control system offers improved performance for electrosurgical vessel sealing and tissue welding. The output power is applied cyclically by a control system with tissue impedance feedback. The impedance of the tissue follows the cyclic pattern of the output power several times, depending on the state of the tissue, until the tissue becomes fully desiccated. High power is applied to cause the tissue to reach a high impedance, and then the power is reduced to allow the impedance to fall. Thermal energy is allowed to dissipate during the low power cycle. The control system is adaptive to tissue in the sense that output power is modulated in response to the impedance of the tissue.

Abstract: The invention is concerned with cauterizing and resecting tissue. A pair of electrodes are placed on opposed tissue surfaces, and radio frequency power is applied through the electrodes to cauterizing a tissue mass therebetween. After cauterization has been effected, the tissue may be resected along a plane within the cauterized region with minimum or no bleeding. The tissue mass may then be removed.

Abstract: An electrosurgical pencil (100) configured and adapted to support an electrocautery blade (116). A strain gauge (130) is affixed to the proximal, end of the electrocautery blade and measures the displacement of the blade as a result of resistance and drag acting on the blade. The electrosurgical pencil also includes a meter electrically connected to the strain gauge for monitoring either a change in voltage, a change in electrical current or a change in optical wavelength. The amount of blade displacement as measured by the strain gauge is available for display to the surgeon and/or as sensory input for a control circuit in the electrosurgical generator (118) that modulates the generator output waveform. The electrosurgical pencil further includes a control circuit electrically coupled between the electrocautery blade and the electrosurgical generator. The control circuit is configured and adapted to control power supplied to electrocautery blade based on the displacement measured by the strain gauge.

Abstract: A thermocouple measuring circuit for sensing a temperature at a measuring point is provided. The thermocouple measurement circuit (12) includes a thermocouple input for sensing a temperature at a measuring point, a compensation circuit (14) for compensating thermocouple effects of junctions of the thermocouple, and an instrumentation amplifier (16) for summing an output of the thermocouple and an output of the compensation circuit and outputting a voltage indicative of the temperature sensed, wherein the output of the compensation circuit is a reference voltage for the output of the instrumentation amplifier. Various embodiments of the thermocouple measurement circuit may be employed in electrosurgical generators for controlling output power dependent on temperature conditions.

Abstract: A high-frequency cauterization power supply apparatus is provided with an electrosurgical scalpel device. When an operator starts to excise a living tissue in a conductive liquid, high-frequency power is applied to a treatment electrode. When an output impedance detected at that time is lower than a preset value, a variable DC power source circuit (HVPS) is set to a constant-current control mode. High-frequency power including an instantaneous high voltage is intermittently applied to the treatment electrode in a state that current output is kept at a fixed value, whereby a discharging operation starts. When the output impedance value is larger than a preset value or is large, the variable DC power source circuit is set to a constant-voltage control mode, electric power having a predetermined voltage value is supplied to the treatment electrode, whereby a living tissue to be cauterized is cauterized by using an appropriate high-frequency current.

Abstract: An electrosurgical generator has a control system formed by an array of logic gates programmed to execute mathematical algorithms for regulating at least one parameter of output power, output voltage or output current of an output electrosurgical signal in a closed loop response to sensed values of the output voltage and the output current.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes a multiple-secondary transformer configured for sensing voltage. The multiple-secondary transformer includes a primary winding coupled to an active terminal and a return terminal of the electrosurgical system and a plurality of secondary windings. Each of the secondary windings is configured to transform the radio frequency voltage into a sensed voltage. Each of the secondary windings includes an output coupled to a sensor circuit and configured to transmit the sensed voltage to the sensor circuit.

Abstract: Voltage and current of an electrosurgical output signal which is conducted by a transformer are accurately simulated by executing a simulation algorithm to compensate for inherent distortion in the values of the current and voltage induced between primary and secondary windings of the transformer. The simulation algorithm is executed in response to voltage and current signals from a primary winding of the transformer, which may be a power output transformer or part of an electrosurgical output signal sensor.

Abstract: In an electrosurgical generator for generating radio frequency power, the generator comprises a radio frequency output stage having three or more output connections, one or more sources of output power coupled to the output stage, and a controller operable to cause the generator to supply a first cutting RF waveform to the output connections or a second coagulating RF waveform to the output connections. In a combined mode, the controller causes the generator to deliver both first and second RF waveforms, the controller including means for feeding the waveforms to the output connections such that the first RF waveform is delivered between a first pair of the output connections, and the second RF waveform is delivered between a second pair of the output connections. The combined mode is adjustable between various settings, each setting having a different proportion of the first and second RF waveforms.

Abstract: A system including at least two target electrodes and at least one return electrode spaced outwards from the at least two target electrodes, at least two RF power sources in electrical communication with the electrodes and operative to generate RF energy waveforms to the at least two target electrodes, a controller in operative communication with the at least two RF power sources to control delivery of RF energy in a monopolar mode, a bipolar mode or a combined monopolar and bipolar mode, wherein in the monopolar mode at least one of the at least two target electrodes is energized by one of the RF power sources and cooperates with the at least one return electrode to deliver monopolar RF energy towards a first spatial region, and wherein in the bipolar mode the at least two target electrodes are energized by the at least two RF power sources to deliver bipolar RF energy between the at least two target electrodes in a second spatial region different from the first spatial region, and wherein in the combined mo

Abstract: A method and apparatus for fractional treatment of skin by irradiating the skin with electromagnetic energy is disclosed. Sources of the electromagnetic energy can include radio frequency (RF) generators, lasers, and flashlamps. The apparatus includes at least one sensor configured to detect a positional parameter, a skin characteristic, a skin response, or combinations thereof. The sensor provides feedback to a controller. The controller controls the treatment parameters, including the treatment density. By sensing the positional parameter, skin characteristic and/or skin response to a treatment, the controller automatically adjusts treatment density in real-time in response to the sensed positional parameter, skin characteristic and/or skin response.

Abstract: An electrosurgical system and method are disclosed. The system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The generator is further adapted to supply an electrical signal having at least one substantially constant value to tissue to determine initial tissue impedance response. The generator includes sensor circuitry adapted to continuously monitor initial tissue impedance response, wherein the initial tissue impedance response includes one of an initial impedance, an impedance drop, an impedance minimum and a first impedance rise. The generator also includes a microprocessor adapted to generate at least one tissue parameter based as a function of the initial impedance, the impedance drop, the impedance minimum and the first impedance rise. The system also includes an electrosurgical instrument including at least one active electrode adapted to apply electrosurgical energy to tissue for treatment.

Abstract: An electrosurgical system for sealing tissue is disclosed which includes an electrosurgical forceps having a shaft member and a jaw member disposed at a distal end thereof. The jaw members are movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members cooperate to grasp tissue therebetween. Each of the jaw members including a sealing plate which communicates electrosurgical energy through tissue held therebetween. The jaw members are adapted to connect to an electrosurgical generator. The system also includes one or more sensors which determine a gap distance between the sealing plates of the jaw members and a microprocessor which is adapted to communicate with the sensor and measure an initial gap distance between the sealing plates as well as to generate a desired gap distance trajectory based on the initial gap distance.

Abstract: An bipolar electrosurgical tool (10) for cauterizing or ablating tissue. The tool has a nose cone (12) which serves as a handle. A conductive shaft (14) extends from the nose cone. A tip assembly (18) with an active electrode (20) is mounted to the shaft. A circuit board (78) is mounted in the nose cone. Conductive traces that forming contact pads (96, 102) are formed on the circuit board. A web (108) formed from a single piece of elastomeric material is seated over the opening in which the printed circuit board is mounted to seal the opening shut. Integrally formed with the web are buttons (116, 118) that are in registration over the contact pads. The buttons can be depressed downwardly towards the contact pads. When a button is so depressed, a conductive landing pad (120) integral with the button closes the connection between the traces that form the contact pad. Thus, the tool of this invention is provided with switches. The circuit board also has two conductive traces (92, 104a) that run in parallel.

Abstract: A method for electrosurgically sealing a tissue includes steps of: (A) applying a first pulse of RF energy to the tissue; and (B) applying at least one subsequent RF energy pulse to the tissue and keeping constant or varying RF energy parameters of individual pulses in accordance with at least one characteristic of an electrical transient that occurs during the individual RF energy pulses. The method terminates the generation of subsequent RF pulses upon a determination that the electrical transient has passed a predetermined limit.

Abstract: A multi-channel radio frequency generator for high-frequency thermal treatment is used in combination with a plurality of electrodes. The multi-channel radio frequency generator includes an oscillator for producing a high-frequency, a waveform modulator part for modulating an waveform of the high-frequency generated by the oscillator, first to third amplifying channels for amplifying the high-frequency outputted from the waveform modulator part to have a root mean square output of 30-200 Watts and then supplying the root mean square output to the electrodes, a channel selection part for allowing a user to select one or more of the first to third amplifying channels, a key part for enabling the user to set a voltage, a current and an impedance for the first to third amplifying channels, and a microcontroller unit for controlling a power, a time and a phase of the high-frequency outputted from each of the first to third amplifying channels.

Abstract: In an electrosurgical generator for generating radio frequency power, the generator includes a radio frequency output stage having two or more output connections, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to cause the generator to supply a blended output signal alternating constantly between a first output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to at least a first predetermined threshold value for cutting or vaporisation of tissue, and a second output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to a second threshold value for coagulation.

Abstract: An axial elongate bipolar tissue sealer/cutter and method of use by a surgeon for electrosurgery on tissue. A chassis on a handle extends axially for axial movement. An effector on a distal end of the chassis first contacts tissue with axial movement. The effector provides bipolar electrosurgery. A member extending from the distal end is opposite the patient end of a tube. A part on the member is transverse to the axis to conduct electrosurgery. First and second bipolar electrodes on the effector and part are electrically isolated. A generator for bipolar electrosurgery supplies the electrodes. An activator is movably supported on the handle connects to the tube and/or chassis to axially move the patient end and its effector relative to the part. Tissue and bodily fluid therebetween are sealed or cut through application of compression and bipolar electrosurgery between the first and second electrodes.

Abstract: An electrosurgical generator is disclosed capable of controlling the output crest factor, as well as the output power of the electrosurgical generator across a range of tissue impedances during electrosurgery. The control occurs automatically, in real time and continuously during the duration of electrosurgical activation of the electrosurgical generator by varying both the output crest factor and output power based on the changing impedance of the tissue. The electrosurgical generator also includes controls for allowing a surgeon to manually select the appropriate crest factor value and power output value for a particular surgical procedure. By automatically adjusting the output crest factor and by giving the surgeon the ability to manually “tailor” the output crest factor across a range of tissue impedance, the electrosurgical generator enhances the ultimate surgical effect and desirable surgical results.

Abstract: A system for performing an electrosurgical procedure at a surgical site is disclosed. The system includes a sensor configured to continually sense an electrical and/or a physical property of tissue at a surgical site and to generate a sensor signal as a function thereof. The system also includes a control module configured to process the sensor signal using a processor, an algorithm, and a map having one or more predetermined values. The control module is further configured to compare the sensor signal to a predetermined level to determine reliability of the sensor signal and to signal an electrosurgical generator in response to a reliable sensor signal such that the electrosurgical generator enters energy control mode, wherein the electrosurgical generator matches an output of the control signal with a predetermined value from the map.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The electrosurgical generator includes impedance sensing circuitry which measures impedance of tissue, a microprocessor configured to determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid, and an electrosurgical instrument including at least one active electrode adapted to apply electrosurgical energy to tissue.

Abstract: An electrosurgical system is disclosed comprising a generator configured to electrosurgical coagulation waveforms. The generator includes a closed loop control system for controlling the electrosurgical coagulation waveforms. The closed loop control system includes a sensor configured to sense a tissue property and/or an energy property and to transmit the tissue property and/or the energy property as one or more sensor signals having an amplitude. The control system also includes a gain controller configured to process the at least one sensor signal to reduce the amplitude of the sensor signals and to obtain a signal to noise ratio of the at sensor signals within a predetermine range. A microprocessor coupled to the generator and is configured to adjust the electrosurgical coagulation waveforms as a function of the sensor signals.

Abstract: A high-frequency generator for high-frequency surgery is driven by a d.c. voltage supply. This d.c. voltage supply has a first working mode for transferring energy in a direction of the high-frequency generator, and also a second working mode for transferring energy in an opposite direction. With this arrangement, a particularly fast and efficient regulation of output voltage of the generator is possible. Therefore a reliable first cut may be performed on different kinds of tissue without any coagulation. Furthermore, owing to a high efficiency, a particularly small constructional size can be achieved.

Abstract: A high-frequency generator for high-frequency surgery comprises a power generator for supplying high frequency energy at a base frequency. A standardizing factor is determined, with which an output variable from the power generator must be scaled in order to attain a given desired value. Furthermore, harmonics of the base frequency are determined from the output variable and scaled using this factor. By means of an input, the thus obtained signal now controls the output power of the generator. With this arrangement, a reliable first cut may be performed on various kinds of tissue without occurrence of any coagulation.

Abstract: A medical instrument, in particular a generator for high-frequency surgery, comprises setting elements for presetting functions, and also functional elements for performing functions according to the settings. A controller interrogates the setting elements and controls the functional elements accordingly. Furthermore, a safety controller is provided for performing plausibility checks with the aid of information from the setting elements and also the functional elements, and for deactivating, or putting into a safe operating condition, the functional elements in the case of inadmissible working conditions.

Abstract: An electrosurgical generator apparatus controls a variable output signal to electrodes. The generator apparatus operates in a cut mode, a coagulation mode or a stimulate mode. The generator apparatus comprises a DC power supply that provides regulated low voltage and high voltage outputs and a radio frequency (RF) waveform generator circuit that provides pulse duration modulation (PDM) of a carrier signal. The carrier signal directly affects the variable output signal to the electrodes. A control circuit controls a variable output signal to electrodes used in electrosurgical procedures. The control circuit comprises a DC power supply circuit that provides regulated low voltage and high voltage outputs and an RF waveform generator circuit that provides pulse duration modulation of a carrier signal. The carrier signal directly affects the variable output signal to the electrodes.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the impedance of the tissue to be ablated. Rather than attempting to detect a desired drop or a desired increase impedance, completeness of a lesion is detected in response to the measured impedance remaining at a stable level for a desired period of time, referred to as an impedance plateau. The mechanism for determining transmurality of lesions adjacent individual electrodes or pairs may be used to deactivate individual electrodes or electrode pairs, when the lesions in tissue adjacent these individual electrodes or electrode pairs are complete, to create an essentially uniform lesion along the line of electrodes or electrode pairs, regardless of differences in tissue thickness adjacent the individual electrodes or electrode pairs.

Abstract: The control for an ablation catheter provides increased ablation catheter operation feedback and increased options for programmable control of the ablation catheter for clinicians. The control for an ablation catheter has a microcontroller containing memory, an input and output coupled to the microcontroller, a movement program, a comparison program, and an annunciating program. The movement program processes position information from the input to calculate ablation catheter movement. The comparison program compares ablation catheter movement to a predetermined control data.

Abstract: Semi-autonomously executed routines accomplish the primary functions of electrosurgical energy delivery on a responsive basis for power control purposes and to adapt the delivered output waveform to perform new and better surgical procedures. The routines include and output voltage and output current sampling routine, a control routine for establishing the width of drive pulses used to create the output waveform, a pattern generation routine for establishing the pattern of drive pulses to be delivered in one mode cycle established by a selected mode of operation, a pattern delivery routine for repeatedly delivering sequences of the mode cycle pattern of drive pulses, and a power supply control routine for varying the voltage of the drive pulses in coordination with varying the width of the drive pulses.

Abstract: An axial elongate bipolar tissue sealer/cutter and method of use by a surgeon for electrosurgery on tissue. A chassis on a handle extends axially for axial movement. An effector on a distal end of the chassis first contacts tissue with axial movement. The effector provides bipolar electrosurgery. A member extending from the distal end is opposite the patient end of a tube. First and second bipolar electrodes on the effector and a part on the member electrically isolated. A generator supplies the electrodes. An activator is movably supported on the handle and connects to the tube and/or chassis to axially move the effector relative to the part. Tissue and bodily fluid therebetween are sealed or cut through application of compression and bipolar electrosurgery between the first and second electrodes. The effector and the part have complimentary sealing or cutting surfaces for partial mating engagement upon axial movement toward one another.

Abstract: An electrosurgical apparatus comprises a high frequency generator (1) with an associated power control system, a handpiece (2) with means for removably mounting an electrode (5) therein, and a connection cable (3) between an output (4) of the generator and the handpiece. The transfer characteristic of the system provides a substantially true ohmic transfer of loads on the electrode side of the connection cable (3) to the generator side thereof at or around a predetermined load on the electrode. In order to achieve a fully automatic and optimalized control af power supplied from a cutting electrode, whereby the control is instantly responding, to changes in the electrode load, the electrosurgical apparatus is characterized in that the power control system comprises a driver stage (7) followed by a reflectormeter (9) adapted and arranged to sense the generator output (4).

Abstract: In an electrosurgical generator for generating radio frequency power, the generator includes a radio frequency output stage having two or more output connections, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to cause the generator to supply a blended output signal alternating constantly between a first output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to at least a first predetermined threshold value for cutting or vaporisation of tissue, and a second output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to a second threshold value for coagulation.

Abstract: A method for electrosurgically sealing a tissue includes steps of: (A) applying a first pulse of RF energy to the tissue; and (B) applying at least one subsequent RF energy pulse to the tissue and varying RF energy parameters of individual pulses of subsequent RF energy pulses in accordance with at least one characteristic of an electrical transient that occurs during the individual pulses of the subsequent RF energy pulses. The method terminates the generation of subsequent RF pulses upon a determination that the electrical transient has passed a predetermined limit.

Abstract: A system for facilitating the placement of a catheter within the human body, in a lumen or vessel such as the fallopian tubes, and controlling the catheter after placement. The system coordinates the operation of treatment electrodes on the catheter with informative displays and prompts to an operator, based on information derived from electrical parameters of position detection electrodes on the catheter.

Abstract: An electrosurgical generator is disclosed capable of controlling the output crest factor, as well as the output power of the electrosurgical generator across a range of tissue impedances during electrosurgery. The control occurs automatically, in real time and continuously during the duration of electrosurgical activation of the electrosurgical generator by varying both the output crest factor and output power based on the changing impedance of the tissue. The electrosurgical generator also includes controls for allowing a surgeon to manually select the appropriate crest factor value and power output value for a particular surgical procedure. By automatically adjusting the output crest factor and by giving the surgeon the ability to manually “tailor” the output crest factor across a range of tissue impedance, the electrosurgical generator enhances the ultimate surgical effect and desirable surgical results.

Abstract: A high frequency electrosurgical power generator configured to produce electrical power at a frequency of about 1 to about 14 MHz and preferably having an essentially sinusoidal waveform with a voltage level up to 1,000 Vrms, and a current level up to 5 Amps. The output of the high frequency electrosurgical power generator is connected to an electrosurgical tool configured to receive the voltage and current produced by the electrosurgical power generator and deliver the voltage and current to an electrosurgical site. The output of the electrosurgical generator preferably is an essentially sinusoid waveform with a frequency between about 3 MHz and about 8 MHz, up to about 700 volts rms, up to about 2 amps, with a total power of up to 1,000 watts.

Abstract: Instruments for thermally-mediated treatment of a patient's lower esophageal sphincter (LES) to induce an injury healing response to thereby populate the extracellular compartment of walls of the LES with collagen matrices to altere the biomechanics of the LES to provide an increased intra-esophageal pressure for preventing acid reflux. A preferred embodiment is a bougie-type device for trans-esophageal introduction that carries conductive electrodes for delivering Rf energy to walls of the LES (i) to induce the injury healing response or (ii) to “model” collagenous tissues of the LES by shrinking collagen fibers therein. Typically, an Rf source is connected to at least one conductive electrode that may be operated in a mono-polar or bi-polar fashion. A sensor array of individual sensors is provided in the working end.

Abstract: When a user steps on a footswitch, high-frequency output power is delivered. A control circuit included in a diathermic power supply calculates the impedance ZSn that is offered by a living tissue immediately after delivery of high-frequency output power is started during the n-th delivery period. The control circuit also calculates the impedance ZEn that is offered thereby immediately before delivery of high-frequency output power is discontinued with elapse of predetermined time. The control circuit then discontinues delivery of high-frequency output power for the predetermined time, and calculates a difference &Dgr;Zn between the impedances. When the difference meets a predetermined condition that implies coagulation or when the number of times of delivery reaches a predetermined value, the control circuit discontinues delivery of high-frequency output power.

Abstract: A method for calculating the impedance in a first circuit coupling a first radio frequency electrode to a radio frequency controller where the first electrode is disposed in tissue in the vicinity of a second radio frequency electrode coupled to a second circuit. The impedance IMP of the first circuit is measured when energy is being supplied to both electrodes. The impedance IMP0 of the first circuit is also measured when energy is being supplied to the first electrode but not to the second electrode, and subtracted from the impedance value IMP to determine a delta value IMP&Dgr;. The impedance IMP2 of the first circuit is then measured when energy is being supplied to both electrodes. The impedance delta value IMP&Dgr; is subtracted from the impedance value IMP2 to arrive at a calculated impedance value for the first circuit. A computer-readable memory and apparatus utilizing the method are provided.

Abstract: A device for electrothermal treatment of the human or animal body, in particular for tissue coagulation or electrotomy, has an elongate applicator with at least two electrodes for insertion into the body to be treated. To produce an electrical or electromagnetic field for heating the body tissue in the treatment region, the two electrodes are arranged on the applicator in electrically mutually insulated and mutually spaced relationship and are each connected by way of a respective feed line to an extracorporally arranged high-frequency generator, in order to be able better to control the treatment process there is provided a signal source which emits a signal that provides the user with information about the condition of the body tissue between the two electrodes during a treatment process.