Abstract: The present disclosure is directed to an electrosurgical generator an H-bridge and a tank driven by the H-bridge. The tank includes a transformer having a primary winding and a secondary winding. The secondary winding includes a first coil and a second coil. In the electrosurgical generator, a capacitor is connected in series between the first coil and the second coil.

Abstract: The present disclosure is directed to an electrosurgical generator including a tank configured to output energy and an H-bridge configured to drive the tank. The generator also includes a choke. The choke impedes a common mode current generated by the H-bridge and provides a leakage inductance for the tank.

Abstract: The present disclosure is directed to an electrosurgical generator including a resonant inverter having an H-bridge and a tank. The generator also includes a pulse width modulation (PWM) controller configured to output PWM timing signals to the H-bridge. A switch is configured to select a modality from among a plurality of modalities and the PWM controller adjusts a frequency of the PWM timing signals based on the selected modality.

Abstract: The present disclosure is directed to an electrosurgical generator including a resonant inverter having an H-bridge and a tank. The tank includes a transformer including a first core half, a second core half, a primary winding, and a secondary winding having a number of turns, wherein each turn is separated by a gap. The transformer is configured to provide a parallel capacitance based on the gap.

Abstract: 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.

Abstract: 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.

Abstract: The electrosurgical systems and methods according to the present disclosure use a multi-stage power converter for generating electrosurgical energy. The electrosurgical systems include an electrosurgical generator having a power converter coupled to an electrical energy source and configured to generate electrosurgical energy. The power converter includes a boost converter configured to convert a first direct current from the electrical energy source to a second direct current, and a phase-shifted pulse width modulation (PS-PWM) resonant inverter configured to invert the second direct current to an alternating current. The electrosurgical generator also includes a plurality of sensors configured to sense a voltage and a current of the generated electrosurgical energy and a controller coupled to the power converter and the plurality of sensors.

Abstract: The present disclosure is directed to an electrosurgical generator including a resonant inverter having an H-bridge and a tank. A sensor array measures at least one property of the tank. A pulse width modulation (PWM) controller outputs a first PWM timing signal and a second PWM timing signal to the H-bridge. The PWM controller controls a dead-time between the first PWM timing signal and the second PWM timing signal based on the at least one property measured by the sensor array.

Abstract: An electrosurgical generator is disclosed. The generator includes an RF output stage configured to generate at least one electrosurgical waveform including a plurality of cycles; at least one sensor coupled to the RF output stage, the at least one sensor configured to measure a voltage and a current of the at least one electrosurgical waveform; and a controller coupled to the at least one sensor and the RF output stage, the controller including a proportional-integral-derivative controller having at least one of voltage limiter or a current limiter, the proportional-integral-derivative controller configured to saturate the RF output stage based on voltage-current characteristics of the RF output stage.

Abstract: A method for controlling an electrosurgical generator includes generating at least one electrosurgical waveform at a selected energy setting through an RF output stage comprising an RF inverter coupled to a power source. The at least one electrosurgical waveform has a duty cycle and a crest factor. The method also includes adjusting a repetition rate of the at least one electrosurgical waveform based on the selected energy setting to regulate the duty cycle of the at least one electrosurgical waveform. The method also includes applying the at least one electrosurgical waveform to tissue through at least one electrode and measuring an output voltage of the at least one electrosurgical waveform. The method also includes supplying a control signal to the RF inverter based on the repetition rate when the output voltage is increasing to regulate the crest factor of the at least one electrosurgical waveform.

Abstract: An electrosurgical generator is provided. The generator includes a DC-DC buck converter configured to output a DC waveform, the DC-DC buck converter including at least one first switching element operated at a first duty cycle; a DC-AC boost converter coupled to the DC-DC buck converter and including at least one second switching element operated at a second duty cycle, the DC-AC boost converter configured to convert the DC waveform to generate at least one electrosurgical waveform; and a controller coupled to the DC-DC buck converter and the DC-AC boost converter and configured to adjust the first duty cycle and the second duty cycle to operate the at least one electrosurgical waveform in at least one of constant current, constant voltage, or constant power modes.