Abstract: High-frequency device to generate a plasma arc (5) for the treatment of biological tissue (1), in particular in medicine, with a high-frequency generator (3) having an internal resistor (8) and, connected thereto by means of a flexible lead (10), an electrode (4) with which the plasma arc (5) is produced in a plasma segment (6) between the electrode (4) and the biological tissue (1), which is likewise electrically connected to the high-frequency generator (3), such that in the high-frequency generator (3) a high-frequency voltage source (7) is provided to which is connected a resonant circuit (2) that comprises a first reactance element (9a) with a capacitive action and, in series therewith, a second reactance element (9a) with an inductive action, and that has a resonant frequency at the frequency of the high-frequency oscillation emitted by the high-frequency voltage source (7), wherein the voltage to generate the plasma arc (5) is derived from the first or second reactance element (9a, 9b).

Abstract: The present invention relates to a high-frequency surgical generator (1) for adjusted cutting and coagluation having adjustment devices for setting the momentary electric output values, such as, e.g., current, voltage and power and having a device for direct and/or indirect determination of the state of the tissue in the vicinity of the cutting electrodes.

Abstract: A system for controlling the operation of a high frequency biological tissue cutting device for cutting biological tissue with high-frequency current having a HF generator component designed so that the amplitude of the voltage (UG) applied to the tissue can be changed. At least one adjustment device is provided to adjust one of the characteristic values (K) of the high frequency generator component to a 1st desired value (b), related to the output of an indicator device that indicates by an electrical signal (d) the size and intensity of the electric arc occurring between the surgical probe and the tissue during cutting. A desired-value transmitter provides a second desired value (c) representing the desired size and intensity of the electric arc.

Abstract: The present invention relates to a high-frequency surgical generator (1) for adjusted cutting and coagluation having adjustment devices for setting the momentary electric output values, such as, e.g., current, voltage and power and having a device for direct and/or indirect determination of the state of the tissue in the vicinity of the cutting electrode.

Abstract: The present invention relates to high-frequency generator for cutting tissue having adjustment devices, with which at least one of the momentary electric output values, such as e.g., current, voltage, power or electric arc can be set.The present invention is distinguished by, for improvement of the initial incision behavior, an electronic desired-value transmitter and a measurement device having an evaluation unit for direct and/or indirect determination of cutting being provided and said electronic desired-value transmitter providing upon commencement of an incision a particularly suited generator setting for the initial incision as long as said measurement device signals tissue-separating cutting of the probe and thereupon providing a lower desired value for the generator in such a manner that normal cutting corresponding to the desired surgical goal ensues.

Abstract: A high-frequency electrosurgery apparatus for cutting and/or coagulating biological tissues that may have a number of operating modes is described. As control panel on which one or more parameters of the high-frequency output of the apparatus can be set. Particularly important is the current-limiting system which includes setting of a desired maximal current level, to which for a particular mode of operation the current can be limited or in response to which a warning signal may be activated and/or the high-frequency generator shut down. The effective current that the application instrument reaches or exceeds previously set maximal current level. In such a high-frequency electrosurgery apparatus the cable leading to the active electrode is provided with electrial shielding which is connected to the conductor leading to the neutral electrode at a location between the output transformer of the apparatus and the current sensor of the current limiting system.

Abstract: The invention relates to a high-frequency generator with automatic power control for tissue cutting and for coagulating in high-frequency surgery. The power control in the "cutting" mode of operation is effected with an arc control system for keeping the arc burning between the surgical probe and the tissue constant. The high-frequency generator contains a voltage-limiting circuit, which limits the output voltage to a preset maximum value if the arc control system were to adjust a higher voltage.The advantage of the invention lies is a reduction of the mean power delivered to the patient as compared with a high-frequency generator that contains only an arc control system. The cutting quality is not adversely influenced by the power reduction.

Abstract: A self-oscillating inverted rectifier has a series-resonant circuit connected between a load and the selector terminal of an electronically controllable switch, the other terminals of which are connected respectively to d.c. sources of different potential. Phase detection and feedback circuits provide a rectangular control wave for connecting and disconnecting the resonant circuit to each d.c. source only at null transits of the current in the resonant circuit. The feedback circuit includes a control circuit supplied with a regulation voltage, which may be derived from the load, whereby the switch is intermittently prevented from connecting the resonant circuit to energizing d.c. for an integral number of half cycles of the resonant frequency. The load may be a high-frequency electrosurgical device or, more generally, a rectifier circuit providing accurately regulated d.c. power to a variable load.

Abstract: A high-frequency power oscillator is built around a power amplifier utilizing semiconductors in a complementary or quasi-complementary stage which operate in a switching mode of operation. The output of the amplifier supplies high-frequency oscillations to a load impedance through an output filter composed of a series-resonant circuit and a parallel-resonant circuit. A feedback driving voltage is obtained from the output filter in a manner providing a first portion of the driving voltage from a voltage present in the parallel-resonant circuit for voltage feedback and a second portion of the driving voltage obtained by current inverse feedback from the current in the series-resonant circuit. These two components of the driving voltage are combined in an addition circuit and supplied to an input of the power amplifier through a pulse modification stage.

Abstract: A power amplifier driven in the switching mode is started into oscillation by a pulse from an auxiliary oscillator when it is first activated. Reactive currents thereby resulting in an output filter network, containing a series resonant circuit followed by a parallel resonant circuit which is connected across a load impedance, then produce the switching in of a feedback circuit, after which the amplifier oscillates in a self-excited mode, at a frequency determined by the tuning of the resonant circuits.

Abstract: A high-frequency generator having automatic power-control for use in high-frequency surgery. The frequency of a high-frequency generator is adjustable by electronic circuit brought by a control circuit to a value such that at the output of the power amplifier there is an optimal phase relation between output voltage and output current, i.e., generally a phase shift of zero. The signal necessary for the control of the output power is obtained from harmonic oscillations generated by the arc at the surgical probe. A harmonic-measuring device to obtain the harmonic oscillations generated by the arc at the surgical probe has a phase-controlled rectifier which is controlled by the oscillator of the high-frequency generator. A simple filter is used at the output of the power amplifier, and the measurement filter used before the harmonic-measuring device can either be completely eliminated or need only be very simple in construction.

Abstract: A power generator is provided to drive an high power ultrasonic transducer at its resonant frequency even under changing conditions cause by e.g. load fluctuations, aging or heating. The power generator uses a variable-controlled oscillator driving a power amplifier; a three winding transformer has one winding coupled to the transducer, one winding coupled to the output of the power amplifier and the third winding coupled to a phase measuring means. The output of the phase measuring means is fed back to the variable-controlled oscillator.

Abstract: A circuit for a selective push-pull amplifier having amplifier triple poles of the same polarity which simultaneously produces high efficiency and low nonlinear distortions. The circuit has control electrodes controlled by out-of-phase control voltages and an output inductance having a center tap which produces a magnetic combination of output currents of the amplifier triple poles. The output electrodes of each triple pole is connected to an output inductance through a transformer having three windings. Two oppositely polarity windings connect the output of the triple poles to the output inductance while the third winding is connected to provide a series resonant circuit.

Abstract: A device and system for the cutting and/or coagulation of human tissue with the use of high frequency currents. This invention is used to cut materials similar to the human tissue which can emit steam or gassy products when sufficiently heated. It controls the extent of the arc generated during the cutting operation, and controls the heat generated during the coagulating operation, both of these for the purpose of minimizing formation of harmful forms of albumen.

Abstract: In a surgical system for high frequency electrical cutting and cauterizing circuitry to prevent stray currents from harming the surgeon or the patient. This circuitry provides a preferred path for undesirable currents, and to indicate to a surgeon when the undesirable currents are too intense.

Abstract: A device and system for the cutting and/or coagulation of human tissue with the use of high frequency currents. This invention is used to cut materials similar to the human tissue which can emit steam or gassy products when sufficiently heated. It controls the extent of the arc generated during the cutting operation, and controls the heat generated during the coagulating operation, both of these for the purpose of minimizing formation of harmful forms of albumen.