Abstract: An electrosurgical generator is disclosed, which includes an RF output stage connected to a DC power supply and first and second connections. The first connection includes a first switching component and a first parallel inductor-capacitor resonant circuit. The second connection includes a second switching components and a second parallel inductor-capacitor resonant circuit. The first and second switching components are configured to open and close at a predetermined frequency based on a phase-correlated dual drive signal emitted by a driver and are in a 180 degree out-of-phase relationship. The first parallel inductor-capacitor resonant circuit is further configured to produce a first half-sinusoidal waveform and the second parallel inductor-capacitor resonant circuit is configured to produce a second half-sin half-sinusoidal waveform.

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: According to one aspect of the present invention, there is provided a treatment device for cutting a living tissue, comprising a main unit which is to be inserted into a body, a tip-end treatment portion which is disposed at a tip end of the main unit to cut the living tissue, a notch groove which is disposed at the tip-end treatment portion and which compresses the living tissue guided into the notch groove, and an electrode which is positioned in a part of the notch groove and which electrically cuts the living tissue compressed by the notch groove.

Abstract: An intelligent selection system for operating an electrosurgical instrument for use by a surgeon that depends primarily on the surgical procedure to be employed. The operating mode as well as other operating parameters can be controlled by the handpiece chosen by the surgeon to perform the procedure. Each handpiece is customized to activate when operated one of several preset operating modes of the electrosurgical instrument.

Abstract: This invention is an improved tissue-localizing device with an electrically energized locator element for fixedly yet removably 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 current 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: A system and method for performing a simulation of an electrosurgical procedure are disclosed. The method includes the steps of generating a three-dimensional medium, which includes one or more material regions representing a physical object. The method also includes the steps of dividing the medium into multiple hexahedron elements to generate a three-dimensional conformal mesh and assigning each element to the material region. The method further includes the steps of calculating an electrical energy solution and a thermal transport solution and generating graphical representations illustrating one or more aspects of the electrical energy and the thermal transport solutions.

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: A power supply and control apparatus operable in a bipolar mode, a unipolar mode, and a combined bipolar/unipolar mode.

Abstract: An electromagnetic pedicle awl utilizes a tightly focused time-varying magnetic flux to create a localized electromotive force (EMF) near the tip of a pedicle awl. The localized EMF creates localized eddy currents in nearby nerves which in turn excite ionic nerve channels, the excitation being detected by an electromyographic recording device. In comparison to the electrically stimulated pedicle awl of the prior art, the electromagnetic pedicle awl only excites nerves directly in front of and directly to the side of the tip. The electromagnetic pedicle awl is comprised of a tapered awl or drill tip in combination with a solid core surrounded by a solenoid. A pulsed electric current source drives the solenoid to create a time-varying magnetic field in the vicinity of the tapered tip. The awl or drill tip may be stationary with respect to the solenoid or it may rotate.

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 surgical instrument includes a hand piece including a probe to be supplied with a high frequency current, a high frequency drive circuit for supplying a high frequency current to the probe and an ultrasonic transducer rigidly secured to the probe to provide an ultrasonic oscillation. The ultrasonic transducer drive circuit adjusts the current being supplied to the ultrasonic transducer and controls the amplitude of oscillations of the ultrasonic transducer according to the impedance value detected at the high frequency drive circuit.

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: The electrode of a manipulator cuts tissue. The scalpel has rectifying circuit for supplying a rectified voltage to a radio frequency circuit which produces an output current signal at a substantially constant frequency to the electrode. The radio frequency circuit has an electronic switch controlled by an oscillator and pilot circuit. According to the method a wave form is applied to the electrode having such a power that the energy transferred to the manipulator is substantially equal to the sum of the energies required to break the bonds of the molecules of the tissue to be cut. The invention relates also to the electronic scalpel carrying out said method.

Abstract: An internal indifferent electrode device including a flexible shaft, an energy transmission device adapted to be inserted into the body supported on the shaft, and a connector adapted to mate with the power return connector of a power supply apparatus.

Abstract: A surgical handpiece having a tip with at least two coaxially spaced electrically conductive tubes. The tubes are separated by an electrical insulator. The interior of the inner tube is used for aspiration of liquefied tissue. The outer tube is surrounded by a soft irrigation sleeve that forms an irrigation fluid path. The distal portion of the interior tube terminates inside of the outer tube so as to form a boiling region. Surgical fluid from the irrigation fluid path can enter the boiling region through a hole or port in the outer tube. Electrical current is passed between the inner and outer tube to rapidly boil any surgical fluid in the boiling region. The boiling fluid rapidly expands out of the ring between the tube ends and forces hot fluid to contact the targeted tissue, thereby liquefying the tissue and allowing the tissue to be aspirated. Such a construction allows the boiling chamber to be self-priming and operate even if the outer tube is occluded with material.

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: An apparatus and method for the dissociation of soft proteinaceous tissue using pulsed rapid variable direction energy field flow fractionization is disclosed. The pulsed rapid disruptive energy field is created by the use of a probe which surrounds the soft proteinaceous tissue to be removed. Once the adhesive mechanism between tissue constituents has been compromised, fluidic techniques are used to remove the dissociated tissue.

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: 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 electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporising 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 vaporising 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 1kW peak by supplying the power bridge from a large reservoir capacitor (60).

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: Improved pacing thresholds for capturing the heart are achieved by forming a discontinuity in the cardiac tissue of the heart chamber, disposing a pacing electrode at a distance less than a space constant of the cardiac tissue from the discontinuity in the cardiac tissue, and applying a stimulus of a first polarity at an energy insufficient to cause the directly stimulated tissue adjacent to the pacing electrode to propagate a depolarization wave through the cardiac tissue mass of the heart chamber but sufficient to induce a transmembrane potential change at the tissue adjacent to the discontinuity that results in a propagated wave front. Thus, pacing energy is advantageously reduced.

Abstract: Improved pacing thresholds for capturing the heart are achieved by forming a discontinuity in the cardiac tissue of the heart chamber, disposing a pacing electrode at a distance exceeding a space constant of the cardiac tissue from the discontinuity in the cardiac tissue, and applying a stimulus of a first polarity at an energy insufficient to cause the directly stimulated tissue adjacent to the pacing electrode to propagate a depolarization wave through the cardiac tissue mass of the heart chamber but sufficient to induce a transmembrane potential change at the tissue adjacent to the discontinuity that results in a propagated wave front. Thus, pacing energy is advantageously reduced.

Abstract: An electrosurgical apparatus comprises an HF generator and an HF instrument, the HF instrument having a first switch and a second switch, the first switch being assigned a first operating state, and the second switch being assigned a second operating state of the HF generator, the first switch and the second switch further being connected to at least one control signal line, there being assigned, furthermore, to the first switch and the second switch signal coding means that, as a function of the switching state of the first and the second switch, generate from a control input signal different control output signals for the optional activation of the first operating state or of the second operating state of the HF generator, which are fed to the HF generator via the common control line, and the HF instrument furthermore having at least a third switch, which is assigned at least a third operating state of the HF generator.

Abstract: An electrosurgical instrument that is capable of generating high-quality RF energy at a single frequency in the MHz range best suited for delicate, precise and quick-healing cutting procedures with low leakage currents using a monopolar handpiece, and also provides high-quality RF energy at the same frequency suited for use for carrying out similar procedures for use with a bipolar handpiece. In a preferred embodiment, the instrument is capable of generating sub-modes of electrosurgical currents with different waveforms optimized for cutting and hemostasis, and the various sub-modes are available for both the monopolar and bipolar handpieces. A preferred operating frequency is in the range of 4 MHz. The instrument includes means for maintaining a substantially constant power output irrespective of selection of one of the sub-modes.

Abstract: A circuit is disclosed which minimizes the amount of tissue vaporized during a first half (positive half cycle) of an electrosurgical current cycle and minimizes the amount of current applied to tissue during a second half (negative half cycle) of the electrosurgical current cycle to control thermal spread. The circuit is preferably provided within an electrosurgical generator which is capable of controlling the amount of energy delivered to a patient during electrosurgery on a per arc basis.

Abstract: An intelligent selection system for operating an electrosurgical instrument for use by a surgeon that depends primarily on the surgical procedure to be employed. The operating mode as well as other operating parameters can be controlled by the handpiece chosen by the surgeon to perform the procedure. Each handpiece is customized to activate when operated one of several preset operating modes of the electrosurgical instrument.

Abstract: Samples are recoverable from very dense tissue utilizing an instrument incorporating a capture component formed with leafs extending to leaf tip regions supporting a stainless steel pursing cable assembly. The cables of this assembly are electrosurgically excited to define a confronting leading edge and extend rearwardly to a terminator component. Motor drive is imparted to the capture component to deploy the leafs at a substantially constant initial angle of attack. During this procedure the terminator component is drawn forwardly by the cable until encountering a cable stop whereupon continued motor operation loads the cables in tension. By applying a preliminary loading tension to the cables before encountering the pursing cable stop, the angle of attack of the leaf tip region is gradually altered to lessen the development of lateral tissue induced forces against the leaf structures.

Abstract: An electrosurgical generator which provides a constant power output particularly suited for cutting arc formation at an active electrode which exhibits a dynamic active surface area of varying geometry. Essentially constant power-based control is achieved through the utilization of a d.c. link voltage the level of which functions to establish the amplitude of the output of an RF resonant inverter. A dual loop feedback control is described wherein output power based control signals are slowly introduced at low gain, while link voltage based controls are comparatively rapidly applied. Enhanced development of a controlling d.c. link voltage is achieved through the utilization of an input network incorporating a power factor correction stage.

Abstract: A percutaneous cellulite removal needle of the present invention can be used to make the appearance of cellulite less obvious by cutting the fibrous bridges that connect the skin to muscle/fascia or fibrous septae in the subcutaneous fat in a minimally invasive manner. The percutaneous cellulite removal needle of the present invention preferably includes a body having an internal chamber that ends at a laterally disposed aperture. A cutting mechanism is substantially positioned within the internal chamber in a retracted position and at least partially protrudes through the laterally disposed aperture in a cutting position. A situating mechanism transitions the cutting mechanism between the retracted position and the cutting position. The present invention also includes a method in which the percutaneous cellulite removal needle is inserted through the skin with the cutting mechanism in the retracted position. The cutting mechanism is then extruded so that the cutting mechanism is in the cutting position.

Abstract: Microfluidic devices and methods for their use in producing pulsed microfluidic jets in a fluid environment are provided. The subject microfluidic devices are characterized by the presence of a microfluid chamber at their distal ends. The microfluid chamber is bounded by an opening at one end, a vapor producing means opposite the opening, and side walls between the opening and the vapor producing means. The microfluid chambers are further characterized in that the only way fluid can exit the microfluid chambers is through the opening. In using the subject devices to produce a fluid jet in a fluid environment, the chamber is first contacted with the fluid environment. The vapor producing means is then actuated in a manner sufficient to produce a vapor bubble in the chamber which, in turn, produces a microfluidic jet in the fluid environment. The subject devices and methods find use in a variety of different applications, e.g., cutting tissue, introducing fluid into a cell, and the like.

Abstract: An electrosurgical working end and method for obtaining a tissue sample for biopsy purposes, for example, from a patient's lung or a liver. The working end provides curved jaw members that are positioned on opposing sides of the targeted anatomic structure. The working end carries a slidable extension member that is laterally flexible with inner surfaced that slide over the jaw members to clamp tissue therebetween. As the extension member advances, the jaws 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 while a cutting element contemporaneously cuts the tissue. By this means, the transected tissue margin is captured under high compression. The working end carries a bi-polar electrode arrangement that engages the just-transected medial tissue layers as well as surface layers to provides Rf current flow for tissue welding purposes that is described as a medial-to-surface bi-polar approach.

Abstract: A method and apparatus is disclosed for mechanically-assisted liposuction treatment. The apparatus includes a hand-holdable housing, an electro-cauterizing cannula assembly, and a reciprocation mechanism. The hand-holdable housing has a cavity adaptable for receipt of a portion of the electro-cauterizing cannula assembly. The electro-cauterizing cannula assembly has a distal end and a proximal end and at least one aspiration aperture about the distal end. The reciprocation mechanism is disposed within the housing and is operably associated with either the cannula so that the cannulas can be selectively caused to reciprocate relative to the housing. As the cannula is caused to reciprocate relative to the housing, the aspiration aperture formed through the distal end of the cannula assembly is caused to undergo periodic displacement.

Abstract: Improved robotic surgery end-effectors include at least one insulation material for inhibiting surface conduction of electrical current in a proximal direction, from a distal active electrode toward the proximal end of the end-effector and toward the rest of the surgical instrument itself. Some embodiments include two layers of insulation to further prevent proximally-directed current. By inhibiting proximal current flow, the end-effectors prevent unwanted patient burns as well as electricity-related wear and tear in and around the area where the end-effector is coupled with the rest of the surgical instrument. In various embodiments, such end-effectors are preferably removably coupleable with a robotic surgical instrument.

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 internal indifferent electrode device including a flexible shaft, an energy transmission device adapted to be inserted into the body supported on the shaft, and a connector adapted to mate with the power return connector of a power supply apparatus.

Abstract: An apparatus for treating body tissue includes a treatment instrument 1 for treating the body tissue and a measuring unit 3 for measuring the actual value of a parameter of the body tissue at at least one measuring point. An identifier 4 is connected to the measuring unit 3 for identifying the body tissue to be treated on the basis of the actual value and for outputting a coordinate signal containing the coordinates of the body tissue to be treated. A positioning device 2 receives the coordinate signal and moves the treatment instrument 1 to the body tissue to be treated. An updating device 8 is connected to the measuring unit 3 and the identifier 4 and outputs an updating signal for triggering renewed measurement of the actual value and renewed identification of body tissue to be treated.

Abstract: A medical probe device comprises a catheter having a stylet guide housing with one or more stylet ports in a side wall thereof and a stylet guide for directing a flexible stylet outward through the stylet port and through intervening tissue at a preselected, adjustable angle to a target tissue. The total catheter assembly includes a stylet guide lumen communicating with the stylet port and a stylet positioned in said stylet guide lumen for longitudinal movement from the port through intervening tissue to a target tissue. The stylet can be an electrical conductor enclosed within a non-conductive layer, the electrical conductor being a radiofrequency electrode. Preferably, the non-conductive layer is a sleeve which is axially moveable on the electrical conductor to expose a selected portion of the electrical conductor surface in the target tissue. The stylet can also be a microwave antenna. The stylet can also be a hollow tube for delivering treatment fluid to the target tissue.

Abstract: Methods for diagnosing skin lesions are disclosed. Generally, the method include topically administering an IRM compound to a treatment area for a period of time and in an amount effective to cause a visible change in the appearance of a skin lesion including, in some cases, causing subclinical lesions to become visible. Suitable IRM compounds include agonists of one or more TLRs.

Abstract: An electrosurgical apparatus comprises an HF generator and an HF instrument, the HF instrument having a first switch and a second switch, the first switch being assigned a first operating state, and the second switch being assigned a second operating state of the HF generator, the first switch and the second switch further being connected to at least one control signal line, there being assigned, furthermore, to the first switch and the second switch signal coding means that, as a function of the switching state of the first and the second switch, generate from a control input signal different control output signals for the optional activation of the first operating state or of the second operating state of the HF generator, which are fed to the HF generator via the common control line, and the HF instrument furthermore having at least a third switch, which is assigned at least a third operating state of the HF generator.

Abstract: A plasma tool adapted to emit high quantum energy inert gas atoms in a stream for cutting, liquefying, or evaporating material such as human tissue during surgical procedures. The apparatus comprises a source of inert gas, a plasma cell in communication with the inert gas source for imparting energy to the inert gas atoms and defined in part by a positive electrode and a negative electrode, at least one power supply electrically connected between the positive and negative electrodes, and means for directing the high quantum energy inert gas atoms at a target. The power supply initially provides an ionization voltage between the negative and positive electrodes to initiate a plasma from the inert gas in the plasma cell, and subsequently provides a pulsed voltage curve to sustain the plasma at a predetermined energy level. Methods for using the tool, including for performing surgical procedures, are also described.

Abstract: An electrosurgical generator which provides a constant voltage and variable power output particularly suited for cutting arc formation at an active electrode which exhibits a dynamic active surface area of varying geometry. Essentially constant voltage-based control is achieved through the utilization of a d.c. link voltage the level of which functions to establish the amplitude of the output of an RF resonant inverter. A dual loop feedback control is described wherein output voltage based control signals are slowly introduced at low gain, while link voltage motor-based controls are comparatively rapidly applied. Enhanced development of a controlling d.c. link voltage is achieved through the utilization of an input network incorporating a power factor correction stage.

Abstract: The present invention provides a bipolar high-frequency treatment tool for coagulating and incising the vital tissue, comprising a pair of jaws provided at a distal end portion of an elongated member such that they can be closed and opened between a closed position and an open position, an operation unit having a handle provided at a proximal end portion of the elongated member, the operation unit closing and opening the jaws when the handle is operated, a first electrode portion provided at one of the jaws, and a second electrode portion provided at the other of the jaws. When vital tissue is gripped between the jaws, the effective electrode surface of the second electrode portion, which is to be brought into contact with the vital tissue, is smaller than that of the second electrode portion.

Abstract: An electromagnetically induced cutting mechanism which can provide accurate cutting operations on both hard and soft materials is disclosed. The electromagnetically induced cutter is capable of providing extremely fine and smooth incisions, irrespective of the cutting surface. Additionally, a user programmable combination of atomized particles allows for user control of various cutting parameters. The various cutting parameters may also be controlled by changing spray nozzles and electromagnetic energy source parameters. Applications for the cutting mechanism include medical, dental, industrial (etching, engraving, cutting and cleaning) and any other environments where an objective is to precisely remove surface materials without inducing thermal damage, uncontrolled cutting parameters, and/or rough surfaces inappropriate for ideal bonding. The cutting mechanism further does not require any films of water or any particularly porous surfaces to obtain very accurate and controllable cutting.

Abstract: A method and apparatus for presbyopia correction via combination of a surgical and pharmacological means are disclosed. The pharmacological means is to either “trigger” or enhance the contraction effect after a surgical method for larger accommodation and/or for more stable post-surgery results. In addition, the invention discloses that lower dose range is especially useful in providing eye drugs that is low enough to be both safe and effective when used together with the surgical methods. The preferred embodiments for the surgical methods to remove a portion of the sclera tissue include lasers at wavelength of (0 19-0.36) um and (0.9-3.2) um and the non-laser device of radio frequency wave, electrode device, bipolar device and plasma assisted device. The preferred embodiment for pharmacological means includes the use of pilocarpine hydrochloride, phosphorothioate, physostigmine or other beta-adrenergic propanolamines.

Abstract: Systems and methods are provided for applying a high frequency voltage in the presence of an electrically conductive fluid to create a relatively low-temperature plasma for ablation of tissue adjacent to, or in contact with, the plasma. In one embodiment, an electrosurgical probe or catheter is positioned adjacent the target site so that one or more active electrode(s) are brought into contact with, or close proximity to, a target tissue in the presence of electrically conductive fluid. High frequency voltage is then applied between the active electrode(s) and one or more return electrode(s) to non-thermally generate a plasma adjacent to the active electrode(s), and to volumetrically remove or ablate at least a portion of the target tissue. The high frequency voltage generates electric fields around the active electrode(s) with sufficient energy to ionize the conductive fluid adjacent to the active electrode(s).

Abstract: The invention relates to an HF generator and to a method for limiting the output effective power of the HF generator, especially for performing HF surgical cutting and coagulation of human or animal tissue. According to the invention, the output voltage and the HF output current of the HF generator are detected by at least two detector devices, the peak values and the effective values of the HF output voltage and of the output current as well as the mean value of the output effective power of the HF generator are determined by an evaluation device, and the calculated mean value is compared to a defined maximum mean value of the output effective power of the HF generator by a comparison device. Afterwards, a modulation device modulates the HF output voltage using a pulse-shaped modulation signal.

Abstract: An electrosurgical generator which provides a constant power output particularly suited for cutting arc formation at an active electrode which exhibits a dynamic active surface area of varying geometry. Essentially constant power-based control is achieved through the utilization of a d.c. link voltage the level of which functions to establish the amplitude of the output of an RF resonant inverter. A dual loop feedback control is described wherein output power based control signals are slowly introduced at low gain, while link voltage based controls are comparatively rapidly applied. Enhanced development of a controlling d.c. link voltage is achieved through the utilization of an input network incorporating a power factor correction stage.

Abstract: Method, system and apparatus for carrying out electrosurgical procedures interstitially. Elevated temperature fluid such as steam generated by an instrument born electrosurgical cutting arc is evacuated through an intake port located adjacent the cutting electrode. Instrument cannula surface heating caused by transport of the heated fluid is isolated. Such thermal isolation is provided by a thermal shield which may be configured as an enveloping sheath.

Abstract: An ultrasonic dissection and coagulation system for surgical use is provided. The system includes an ultrasonic instrument, a control module, and a remote actuator. The ultrasonic instrument has a housing and an elongated body portion extending from the housing. An ultrasonic transducer supported within the housing is operatively connected to a cutting jaw by a vibration coupler. The vibration coupler conducts high frequency vibration from the ultrasonic transducer to the cutting jaw. The cutting jaw has a blade surface which is curved downwardly and outwardly in the distal direction with respect to the longitudinal axis of the elongated body portion along its length such that an angle defined by a line drawn tangent to the blade surface and the longitudinal axis of the elongated body portion varies between 5 degrees and 75 degrees.