Control systems for electrosurgical generator

Patent metadata

Field	Value
Publication number	US-11969201-B2
Application number	US-202117403977-A
Country	US
Kind code	B2
Filing date	Aug 17, 2021
Priority date	Apr 23, 2015
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

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 method for controlling an electrosurgical generator comprising:
generating a first component of an electrosurgical waveform at a first pair of switches of a radio frequency (RF) inverter and a second component of the electrosurgical waveform at a second pair of switches of the RF inverter, wherein the first pair of switches and the second pair of switches are arranged in an H-bridge configuration;
obtaining a measured value of at least one of a voltage, a current, or power of the first and second components of the electrosurgical waveform;
generating a desired value for at least one of the voltage, the current, or the power of the first and second components of the electrosurgical waveform;
generating a phase shift between the first and second components of the electrosurgical waveform based on the measured value and the desired value; and
generating at an RF inverter controller a pulse-width modulation (PWM) signal based on the phase shift to control the RF inverter.

2. The method according to claim 1 , further comprising:
selecting a target value for at least one of the voltage, the current, or the power of the first and second components of the electrosurgical waveform; and
compensating for a first phase based on the target value.

3. The method according to claim 2 , wherein compensating is performed at a proportional-integral-differential (PID) controller.

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

5. The method according to claim 2 , wherein compensating is performed for each period of the PWM signal.

6. The method according to claim 2 , wherein generating the desired value further includes:
calculating a voltage gain and an impedance gain for each of the first and second components of the electrosurgical waveform; and
calculating a phase gain.

7. The method according to claim 6 , wherein generating the desired value further includes:
multiplying the first phase by the impedance gain and the voltage gain to obtain a second phase.

8. The method according to claim 7 , wherein generating the desired value further includes:
multiplying the second phase by the phase gain to obtain a third phase.

9. The method according to claim 6 , wherein generating the desired value further includes:
generating the phase shift for the RF inverter controller in response to an update signal from the RF inverter controller.

10. The method according to claim 2 , wherein generating the desired value further includes:
limiting a third phase within a predetermined range.

11. The method according to claim 10 , further comprising:
scaling the third phase; and
providing the scaled third phase as the phase shift to the RF inverter controller.

12. The method according to claim 10 , further comprising:
adjusting average power of the first and second components of the electrosurgical waveform based on the phase shift.

13. The method according to claim 1 , further comprising providing high voltage direct current (HVDC) to the RF inverter from a power supply.

14. The method according to claim 13 , wherein the PWM signal includes a fixed phase for a phase between the first and second electrosurgical waveforms to control the RF inverter based on a set value of the power supply.

Assignees

• Covidien Lp

Inventors

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

Classifications

• A61B18/1233 Primary

  with circuits for assuring patient safety · CPC title

• A61B18/1206

  Generators therefor · CPC title

• A61B2018/00642

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

• A61B2018/00666

  using a threshold value · CPC title

• A61B2018/0072

  Current · CPC title