Covidien LP

Aaron Mattmiller

Mark A Johnston

Donald L Tonn

Robert H Wham

James A Gilbert

William D Faulkner

Joshua H Johnson

Alexander M Waskiewicz

Edward L Brannan

Dean C Buck

Tom E McMunigal

Gary E MacIndoe

A controller for an electrosurgical generator includes an RF inverter, a signal processor, a software compensator, a hardware compensator, and an RF inverter controller. The RF inverter generates an electrosurgical waveform and the signal processor outputs a measured value of at least one of a voltage, a current, or power of the electrosurgical waveform. The software compensator generates a desired value for at least one of the voltage, the current, or the power of the electrosurgical waveform, and the hardware compensator generates a phase shift based on the measured value and the desired value. The RF inverter controller generates a pulse-width modulation (PWM) signal based on the phase shift to control the RF inverter.

Control systems for electrosurgical generator

The disclosed apparatus relates to an apparatus for sensing current that includes a Rogowski coil assembly and a circuit board. The Rogowski coil assembly has a housing, a slot in the housing configured to receive a conductor through the slot, a Rogowski coil formed within the housing, and a connector. The circuit board has a substantially planar substrate, which has a slot through the substrate configured to receive the Rogowski coil assembly. A complementary connector of the circuit board is configured to receive the connector of the Rogowski coil assembly. The Rogowski coil assembly is positioned through the slot of the substrate, and the complementary connector of the circuit board couples with the connector of the Rogowski coil assembly. In various embodiments, the conductor can be a conductive trace on the substrate of the circuit board, and the Rogowski coil is configured to detect a current through the conductive trace.

Apparatus having a Rogowski coil assembly

An electrosurgical generator includes a gain-compensated full bridge topology. Gain nonlinearity is corrected by applying impedance and phase correction factors to a control loop to achieve a linear gain structure. In embodiments, gain compensation is performed by comparing an RF setpoint signal with a calculated output signal to generate a first error signal. An impedance correction factor is applied to the first error signal to generate a second error signal. The second error signal is processed by a proportional-integral-derivative controller to generate a phase control signal. A phase control correction factor is applied to the phase control signal to generate a corrected pulse width modulation driving signal, which is used to generate PWM driving signals for a full-bridge inverter. One or more sensors provide feedback for comparison with the RF setpoint.

Gain compensation for a full bridge inverter

An electrosurgical generator is presented including a radio frequency (RF) amplifier coupled to an electrical energy source and configured to generate electrosurgical energy, the RF amplifier including an inverter configured to convert a direct current (DC) to an alternating current (AC), and a plurality of sensors configured to sense voltage and current of the generated electrosurgical energy. The electrosurgical generator further includes a controller coupled to the RF amplifier and the plurality of sensors. The electrosurgical may be further configured to determine a power level based on the sensed voltage and the sensed current, determine an efficiency of the electrosurgical generator, and insert a predetermined integer number of off cycles when the efficiency of the electrosurgical generator reaches a threshold power efficiency.

Systems and methods for improving efficiency of electrosurgical generators

A method of improving efficiency of an electrosurgical generator is presented, the method including controlling an output of an electrosurgical generator by converting a direct current (DC) to an alternating current (AC) using an inverter, and sensing a current and a voltage at an output of the inverter. The method further includes the steps of determining a power level based on the sensed voltage and the sensed current, determining an efficiency of the electrosurgical generator, and inserting a predetermined integer number of off cycles when the efficiency of the electrosurgical generator reaches a threshold power efficiency.

An electrosurgical generator and related systems and methods using a gain-compensated full bridge topology. Gain nonlinearity is corrected by applying impedance and phase correction factors to a control loop to achieve a linear gain structure. In embodiments, gain compensation is performed by comparing an RF setpoint signal with a calculated output signal to generate a first error signal. An impedance correction factor is applied to the first error signal to generate a second error signal. The second error signal is processed by a proportional-integral-derivative controller to generate a phase control signal. A phase control correction factor is applied to the phase control signal to generate a corrected pulse width modulation driving signal, which is used to generate PWM driving signals for a full-bridge inverter. One or more sensors provide feedback for comparison with the RF setpoint.

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Longmont, CO, United States of America

Aaron Mattmiller