Systems and methods for generating electrosurgical energy using a multistage power converter
First Claim
1. An electrosurgical generator comprising:
- a power converter coupled to an electrical energy source and configured to generate electrosurgical energy, the power converter including;
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;
a plurality of sensors configured to sense voltage and current waveforms of the generated electrosurgical energy; and
a controller coupled to the power converter and the plurality of sensors, the controller comprising;
a signal processor configured to determine a tissue impedance based on the sensed voltage and current waveforms; and
an output controller configured to select one among a plurality of output characteristics based on the tissue impedance, and to generate a first control signal to control the boost converter and a second control signal to control the PS-PWM resonant inverter, according to the selected output characteristic,wherein a switching frequency of the boost converter is greater than a switching frequency of the PS-PWM resonant inverter and the switching frequency of the boost converter is an integer multiple of the switching frequency of the PS-PWM resonant inverter,wherein the plurality of output characteristics include a constant current output characteristic, a constant voltage output characteristic, and a constant power output characteristic,wherein, when the output characteristic is the constant voltage output characteristic, the output controller generates the second control signal having a first fixed phase and a varying duty cycle, andwherein, when the output characteristic is the constant power output characteristic, the output controller generates the second control signal having a second fixed phase, which is different from the first fixed phase, and a fixed duty cycle.
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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. The controller includes a signal processor configured to determine tissue impedance based on the sensed voltage and current, and an output controller configured to select one of a plurality of output characteristics based on the determined tissue impedance, and to generate control signals to control the boost converter and the PS-PWM resonant inverter, according to the selected output characteristic.
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Citations
14 Claims
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1. An electrosurgical generator comprising:
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a power converter coupled to an electrical energy source and configured to generate electrosurgical energy, the power converter including; 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; a plurality of sensors configured to sense voltage and current waveforms of the generated electrosurgical energy; and a controller coupled to the power converter and the plurality of sensors, the controller comprising; a signal processor configured to determine a tissue impedance based on the sensed voltage and current waveforms; and an output controller configured to select one among a plurality of output characteristics based on the tissue impedance, and to generate a first control signal to control the boost converter and a second control signal to control the PS-PWM resonant inverter, according to the selected output characteristic, wherein a switching frequency of the boost converter is greater than a switching frequency of the PS-PWM resonant inverter and the switching frequency of the boost converter is an integer multiple of the switching frequency of the PS-PWM resonant inverter, wherein the plurality of output characteristics include a constant current output characteristic, a constant voltage output characteristic, and a constant power output characteristic, wherein, when the output characteristic is the constant voltage output characteristic, the output controller generates the second control signal having a first fixed phase and a varying duty cycle, and wherein, when the output characteristic is the constant power output characteristic, the output controller generates the second control signal having a second fixed phase, which is different from the first fixed phase, and a fixed duty cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification