Abstract: An electrosurgical system having an ultrasound generator, configured to emit a high-frequency electrical signal, and an ultrasound instrument, including an ultrasound transducer configured to convert the signal into an ultrasound oscillation, wherein the generator is further configured to determine a resonance frequency of the transducer and adapt a frequency of the signal to the resonance frequency, and wherein the generator is further configured to detect a phase position between the current and the voltage of the signal and based on the detected phase position to determine whether the frequency of the signal corresponds to the resonance frequency. To enable the resonance frequency of the transducer to be determined correctly irrespective of component tolerances, the electrosurgical system is characterized in that the generator is configured to consider, during determination of the phase position, correction values, which are or can be stored in a memory of the generator and/or of the instrument.

Abstract: A method for monitoring a high resistance condition at an instrument terminal of an electrosurgical generator, which includes current and voltage measuring devices for determining a current and a voltage at the terminal to determine the high resistance condition, and includes a calculation device connected to the measuring devices which is configured to evaluate the determined current and voltage, including: determining a crest factor value from the current and/or voltage, wherein the crest factor value describes a ratio of a peak value to an effective value of the current and/or voltage; comparing the determined crest factor value with a comparison value by means of a comparison device, wherein the comparison value is stored in a data storage device; and signaling a high resistance condition with a signaling device when the determined crest factor reaches or exceeds the predetermined crest factor comparison value. Also, an electrosurgical generator and electrosurgical generator system.

Abstract: An electrosurgical generator which outputs high-frequency AC voltage for an electrosurgical instrument includes a leakage current detecting device for the connected electrosurgical instrument. The leakage current detecting device is embodied as a voltage measuring device, the inputs of which are connected in each case via a capacitive coupling to an active and a neutral line of the output line and which has a bipolar voltage divider having a predetermined fixed ratio. An asymmetry detector connected via a capacitive coupling compares upper and lower voltage at the voltage divider, and outputs a fault signal for leakage current in the case of deviation of the ratio of upper to lower voltage from the predetermined fixed ratio.

Abstract: An electrosurgical generator for an electrosurgical instrument includes a DC voltage supply and a high-voltage inverter that generates a high-frequency AC voltage having a variable voltage and frequency that is output at an output for the connection of the electrosurgical instrument. The inverter is configured as a multilevel inverter and includes a plurality of inverter cells connected in a cascaded manner that are driven by a control device. Thanks to the cascading, switching losses incurred in the power semiconductors are reduced, both in terms of value (through the divided and thus lower voltage) and in terms of frequency (through the reduced switching frequency).

Abstract: An electrosurgical generator for an electrosurgical instrument includes DC voltage supply and high-voltage inverter that generates high-frequency AC voltage having variable voltage and frequency. Inverter is multilevel inverter controlled by reference signal and having at least two groups of series-connected inverter cells, wherein each group is supplied with different DC voltage and wherein the voltages output by the two groups are summed to be output at output. Group supplied with higher voltage enables fast and large voltage changes with its inverter cells, while inverter cells of other group supplied with lower voltage allow fine setting with high change speed. Dynamic range is improved both from temporal viewpoint and in terms of increased voltage span. The number of HVC cells to be switched may furthermore be varied by way of modulator, wherein further number of LVC cells are switched in an opposing manner for compensation purposes. Switching losses may be reduced.

Abstract: An electrosurgical generator comprising two HF generator units, two output transformers, and at least four output terminals for connecting electrosurgical instruments. Together with the associated output transformer and corresponding output terminals, each HF generator unit forms an HF generator module.

Abstract: An electrosurgical generator having connectors for an electrosurgical instrument including a high-voltage generator electrically connected to the connectors and produces a high-frequency alternating current in its activated state and output said high-frequency alternating current via the connectors. The electrosurgical generator has an effective power determination unit including a phase shift determination unit that supplies an output signal representing a phase shift between the current and the voltage of an alternating current output during operation. The phase shift determination unit produces a pulsed DC voltage signal, in which the pulse width reflects a time difference between the zero crossings of the current and the voltage—and consequently the phase shift—and to process the pulsed DC voltage signal by way of a low-pass filter to form a low-pass filter output signal, the magnitude of which depends on the pulse width of the pulses of the pulsed DC voltage signal.

Abstract: An electrosurgical system for treating tissue, including a first and second electrode; a high-frequency high-voltage supply unit which can be electrically connected to first and second electrode and is designed to supply a specified treatment alternating voltage to electrodes; and a measuring unit which can be electrically connected to first and second electrode and has a measurement voltage supply module that is designed to provide a measurement alternating voltage of at least one first and second frequency, wherein the measuring unit is additionally designed to receive an electric response signal for first and second frequency via first and second electrode and determine at least one property of a tissue located between first and second electrode therefrom. The electrosurgical system relates further to an electrosurgical generator for treating tissue, to a method of operating an electrosurgical system, to using electrosurgical system and to applying the method of operating an electrosurgical system.

Abstract: A method for operating an electrosurgical system including an ultrasound generator and an ultrasonic instrument, includes the steps: determining an initial resonant frequency of the ultrasonic instrument by the ultrasound generator, energizing the ultrasonic instrument by the ultrasound generator with an operating amplitude and an operating frequency which correspond to the initial resonant frequency, tracking the operating frequency of the ultrasound generator with changes in the resonant frequency of the ultrasonic instrument, and terminating the energizing of the ultrasonic instrument by the ultrasound generator. A method terminates the energizing of the ultrasonic instrument by the ultrasound generator, in a decay phase the operating amplitude of the ultrasound generator is reduced to zero with a predefined or predefinable rate of change. An ultrasound generator is also presented.

Abstract: An electrosurgical system having an ultrasound generator, configured to emit a high-frequency electrical signal, and an ultrasound instrument, including an ultrasound transducer configured to convert the signal into an ultrasound oscillation, wherein the generator is further configured to determine a resonance frequency of the transducer and adapt a frequency of the signal to the resonance frequency, and wherein the generator is further configured to detect a phase position between the current and the voltage of the signal and based on the detected phase position to determine whether the frequency of the signal corresponds to the resonance frequency. To enable the resonance frequency of the transducer to be determined correctly irrespective of component tolerances, the electrosurgical system is characterized in that the generator is configured to consider, during determination of the phase position, correction values, which are or can be stored in a memory of the generator and/or of the instrument.

Abstract: A plasma surgery apparatus includes an HF generator for generating an HF activation signal, a gas source for providing a plasma gas, and a plasma applicator having a channel which opens out at a distal end of the applicator and through which the plasma gas can flow. The apparatus also includes an HF electrode that is electrically connected to the HF generator. When the HF electrode is supplied with the HF activation signal, a plasma is provided originating from the distal end of the applicator. The apparatus also includes a control unit and a flow regulator for regulating a flow rate the plasma gas in the channel. The control unit receives or requests an operating variable of the HF generator and, according to a saved functional relationship, controls the flow regulator so that the flow rate of the plasma gas is correlated with a detected value of the operating variable.

Abstract: An electrosurgical system for treating tissue, including a first and second electrode; a high-frequency high-voltage supply unit which can be electrically connected to first and second electrode and is designed to supply a specified treatment alternating voltage to electrodes; and a measuring unit which can be electrically connected to first and second electrode and has a measurement voltage supply module that is designed to provide a measurement alternating voltage of at least one first and second frequency, wherein the measuring unit is additionally designed to receive an electric response signal for first and second frequency via first and second electrode and determine at least one property of a tissue located between first and second electrode therefrom. The electrosurgical system relates further to an electrosurgical generator for treating tissue, to a method of operating an electrosurgical system, to using electrosurgical system and to applying the method of operating an electrosurgical system.

Abstract: An electrosurgical generator having connectors for an electrosurgical instrument including a high-voltage generator electrically connected to the connectors and produces a high-frequency alternating current in its activated state and output said high-frequency alternating current via the connectors. The electrosurgical generator has an effective power determination unit including a phase shift determination unit that supplies an output signal representing a phase shift between the current and the voltage of an alternating current output during operation. The phase shift determination unit produces a pulsed DC voltage signal, in which the pulse width reflects a time difference between the zero crossings of the current and the voltage—and consequently the phase shift—and to process the pulsed DC voltage signal by way of a low-pass filter to form a low-pass filter output signal, the magnitude of which depends on the pulse width of the pulses of the pulsed DC voltage signal.

Abstract: A generator for the delivery of high frequency alternating current to a medical instrument has a power supply unit, a high frequency generator primary unit (HF generator primary unit), an application unit, and a control unit. The HF generator primary unit is connected to the power supply unit and the application unit and designed to supply the application unit with high frequency alternating current during operation. The application unit is electrically connected in a switchable manner to connections for connecting a medical instrument via at least one relay. The control unit is galvanically separated from the application unit and designed to control the at least one relay and the application unit as applicable. The control unit is connected to the application unit via an intermediate control circuit, wherein the intermediate control circuit is galvanically separated both from the control unit and from the application unit.

Abstract: A plasma surgery apparatus includes an HF generator for generating an HF activation signal, a gas source for providing a plasma gas, and a plasma applicator having a channel which opens out at a distal end of the applicator and through which the plasma gas can flow. The apparatus also includes an HF electrode that is electrically connected to the HF generator. When the HF electrode is supplied with the HF activation signal, a plasma is provided originating from the distal end of the applicator. The apparatus also includes a control unit and a flow regulator for regulating a flow rate the plasma gas in the channel. The control unit receives or requests an operating variable of the HF generator and, according to a saved functional relationship, controls the flow regulator so that the flow rate of the plasma gas is correlated with a detected value of the operating variable.