Control systems for electrosurgical generator

Patent metadata

Field	Value
Publication number	US-11090106-B2
Application number	US-201615098822-A
Country	US
Kind code	B2
Filing date	Apr 14, 2016
Priority date	Apr 23, 2015
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

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.

First claim

What is claimed is:

1. A controller for an electrosurgical generator, the controller comprising:
a radio frequency (RF) inverter including an H-bridge configured to generate a first electrosurgical waveform from a first pair of switches of the H-bridge and a second electrosurgical waveform from a second pair of switches of the H-bridge;
a signal processor configured to output a measured value of at least one of a voltage, a current, or a power of the first and second electrosurgical waveforms;
a software compensator configured to generate a desired value for at least one of the voltage, the current, or the power of the first and second electrosurgical waveforms;
a hardware compensator configured to generate a phase shift between the first and second electrosurgical waveforms based on the measured value and the desired value; and
an RF inverter controller configured to generate a pulse-width modulation (PWM) signal based on the phase shift to control the RF inverter.

2. The controller according to claim 1 , wherein the hardware compensator includes:
a setpointer configured to select a target value for at least one of the voltage, the current, or the power of the first and second electrosurgical waveforms; and
a compensator configured to compensate for a first phase based on the target value.

3. The controller according to claim 2 , wherein the compensator includes a proportional-integral-differential (PID) controller.

4. The controller according to claim 3 , wherein the PID controller implements a second order PID algorithm.

5. The controller according to claim 2 , wherein the software compensator and the hardware compensator perform compensation for each period of the PWM signal.

6. The controller according to claim 2 , wherein the hardware compensator further includes:
an impedance gain scheduler configured to calculate an impedance gain;
a voltage gain scheduler configured to calculate a voltage gain; and
a phase gain scheduler configured to calculate a phase gain.

7. The controller according to claim 6 , wherein the hardware compensator is further configured to multiply the first phase by the impedance gain and the voltage gain to obtain a second phase.

8. The controller according to claim 7 , wherein the hardware compensator is further configured to multiply the second phase by the phase gain to obtain a third phase.

9. The controller according to claim 6 , wherein the hardware compensator is further configured to generate the phase shift for the RF inverter controller in response to an update signal from the RF inverter controller.

10. The controller according to claim 8 , wherein the hardware compensator further includes a limiter configured to limit the third phase within a predetermined range.

11. The controller according to claim 10 , further comprising a scale configured to scale the third phase and provide the scaled third phase as the phase shift to the RF inverter controller.

12. The controller according to claim 1 , wherein the RF inverter is further configured to adjust average power of the first and second electrosurgical waveforms based on the phase shift, the phase shift being from about zero to about pi radian.

13. The controller according to claim 1 , wherein the signal processor is further configured to decimate and filter sensed voltage and current waveforms of the first and second electrosurgical waveforms to provide first and second path data to the software compensator.

14. An electrosurgical generator comprising:
a radio frequency (RF) inverter including an H-bridge configured to generate a first electrosurgical waveform from a first pair of switches of the H-bridge and a second electrosurgical waveform from a second pair of switches of the H-bridge;
a plurality of sensors coupled to the RF inverter and configured to sense a voltage waveform and a current waveform of the first and second electrosurgical waveforms;
a plurality of analog-to-digital converters (ADCs) configured to digitally sample the sensed voltage and current waveforms; and
a controller coupled to the plurality of ADCs, the controller including:
a signal processor configured to output a measured value of at least one of a voltage, a current, or a power of the first and second electrosurgical waveforms;
a software compensator configured to generate a desired value for at least one of the voltage, the current, or the power of the first and second electrosurgical waveforms;
a hardware compensator configured to generate a phase shift between the first and second electrosurgical waveforms based on the measured value and the desired value; and
an RF inverter controller configured to generate a pulse-width modulation (PWM) signal based on the phase shift to control the RF inverter.

15. An electrosurgical generator comprising:
a power supply configured to output high voltage direct current (HVDC) power;
a radio frequency (RF) inverter coupled to the power supply, wherein the RF inverter includes an H-bridge configured to generate a first electrosurgical waveform from a first pair of switches of the H-bridge and a second electrosurgical waveform from a second pair of switches of the H-bridge;
a plurality of sensors configured to sense a voltage waveform and a current waveform of the first and second electrosurgical waveforms;
a plurality of analog-to-digital converters (ADCs) configured to digitally sample the sensed voltage and current waveforms; and
a controller coupled to the plurality of ADCs, the controller including:
a signal processor configured to output a measured value of at least one of a voltage, a current, or a power of the first and second electrosurgical waveforms based on the digitally sampled voltage and current waveforms;
a HVDC setpointer configured to set a desired value for the HVDC power; and
an RF inverter controller configured to generate a pulse-width modulation (PWM) signal having a fixed phase for a phase between the first and second electrosurgical waveforms to control the RF inverter based on the desired value.

16. The electrosurgical generator according to claim 15 , wherein the fixed phase is in a range where the RF inverter operates in zero voltage switching.

17. The electrosurgical generator according to claim 15 , wherein the signal processor is further configured to calculate a phase shift.

18. The electrosurgical generator according to claim 17 , wherein the signal processor is further configured to compare the phase shift with the fixed phase.

19. The electrosurgical generator according to claim 18 , wherein the HVDC setpointer is further configured to decrease the desired value for the HVDC power when the phase shift is less than the fixed phase.

20. The electrosurgical generator according to claim 18 , wherein the HVDC setpointer is further configured to increase the desired value for the HVDC power when the phase shift is greater than a threshold.

Assignees

• Covidien Lp

Inventors

• Wham Robert H
• Tonn Donald L
• Mattmiller Aaron
• Faulkner William D
• Brannan Edward L
• Johnston Mark A

Classifications

• A61B2018/0075

  Phase · CPC title

• A61B2018/00666

  using a threshold value · CPC title

• A61B18/1206

  Generators therefor · CPC title

• A61B2018/00642

  with feedback, i.e. closed loop control · CPC title

• A61B2018/00767

  Voltage · CPC title