Electrosurgical generator apparatus

• US 20040082946A1
• Filed: 10/24/2002
• Published: 04/29/2004
• Est. Priority Date: 10/24/2002
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Valley Forge Scientific Corporation (Bausch Health Cos., Inc.)
• Inventors: Solt, David L., Acorcey, Robert R., Groch, Anthony John, Malis, Jerry L., Malis, Leonard L.
• Granted Patent: US 7,041,096 B2
• Time in Patent Office: Days
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2018/0075 Phase
• CPC Class Codes: A61B 2018/00755 Resistance or impedance
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body

Abstract

An electrosurgical generator apparatus controls a variable output signal to electrodes. The generator apparatus operates in a cut mode, a coagulation mode or a stimulate mode. The generator apparatus comprises a DC power supply that provides regulated low voltage and high voltage outputs and a radio frequency (RF) waveform generator circuit that provides pulse duration modulation (PDM) of a carrier signal. The carrier signal directly affects the variable output signal to the electrodes. A control circuit controls a variable output signal to electrodes used in electrosurgical procedures. The control circuit comprises a DC power supply circuit that provides regulated low voltage and high voltage outputs and an RF waveform generator circuit that provides pulse duration modulation of a carrier signal. The carrier signal directly affects the variable output signal to the electrodes.

Claims

1. A control circuit that controls a variable output signal to electrodes used in electrosurgical procedures, the control circuit comprising:

(a) a DC power supply circuit that provides regulated low voltage and high voltage outputs; and

(b) a radio frequency (RF) waveform generator circuit that provides pulse duration modulation of a carrier signal, the carrier signal directly affecting the variable output signal to the electrodes.

2. The control circuit according to claim 1, wherein the RF waveform generator circuit includes at least one shift register integrated circuit (IC) device.

3. The control circuit according to claim 1, wherein the RF waveform generator circuit includes two shift register integrated circuit (IC) devices and a processor.

4. The control circuit according to claim 3, wherein the processor is a microcontroller that has a controlling program for generating a plurality of different user selectable waveforms based on the pulse duration modulation of the carrier signal.

5. An electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in either a cut mode or a coagulation mode, the generator apparatus comprising:

(a) a DC power supply that provides regulated low voltage and high voltage outputs; and

(b) a radio frequency (RF) waveform generator circuit that provides pulse duration modulation of a carrier signal, the carrier signal directly affecting the variable output signal to the electrodes.

6. An electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode, the generator apparatus comprising:

(a) a DC power supply that provides regulated low voltage and high voltage outputs; and

(b) an off-line switching power supply that provides a high voltage DC output to a radio frequency (RF) waveform generator circuit, the RF waveform generator circuit providing pulse duration modulation of a carrier signal, the carrier signal directly affecting the variable output signal to the electrodes.

7. An electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode, the generator apparatus comprising:

(a) a controller for controlling the generator apparatus;

(b) a memory that stores data for the controller; and

(c) a touchscreen interface that communicates with the controller to display the data from the memory and that allows a user to enter a setting.

8. The electrosurgical generator apparatus of claim 7, wherein the touchscreen has an on-screen indicator for displaying the data.

9. The electrosurgical generator apparatus of claim 8, wherein the on-screen indicator is an alphanumeric value.

10. The electrosurgical generator apparatus of claim 8, wherein the on-screen indicator is a bar graph.

11. The electrosurgical generator apparatus of claim 8, wherein the on-screen indicator displays at least one of a pulse width setting, a frequency setting, a voltage setting, an amperage setting, a measured temperature value, a temperature setpoint value, a measured impedance value, an actual time, an elapsed time, a remaining time, and a time setpoint value.

12. The electrosurgical generator apparatus of claim 8, wherein the on-screen indicator displays at least one of an operating mode, an alarm status, a calibration status, a maintenance status, and a selected user parameter.

13. The electrosurgical generator apparatus of claim 7, wherein the touchscreen has an on-screen field for allowing a user to enter a setpoint.

14. The electrosurgical generator apparatus of claim 13, wherein the on-screen field allows entry of at least one of a pulse width setting, a frequency setting, a voltage setting, an amperage setting, a temperature setpoint value, and time setpoint value.

15. The electrosurgical generator apparatus of claim 7, wherein the touchscreen has an on-screen software pushbutton having a first state and a second state.

16. The electrosurgical generator apparatus of claim 7, wherein the touchscreen has an on-screen software selector switch having a first position and a second position.

17. An electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode, the generator apparatus comprising:

(a) a DC power supply that provides regulated low voltage and high voltage outputs;

(b) a radio frequency (RF) waveform generator circuit that provides modulation of a carrier signal, the carrier signal directly affecting the variable output signal to the electrodes;

(c) an impedance monitoring circuit that detects an impedance as measured across a pair of leads of the electrodes, the impedance being correspondingly proportional to an amount of cell destruction caused by the generator apparatus.

18. The electrosurgical generator apparatus according to claim 17, wherein the impedance monitoring circuit further comprises a bridge detector for measuring an overall signal and a reference detector for measuring a reference signal.

19. The electrosurgical generator apparatus according to claim 18, wherein the bridge detector further comprises a bridge in-phase detector for measuring overall in-phase components of the overall signal and a bridge quadrature detector for measuring overall quadrature components of the overall signal.

20. The electrosurgical generator apparatus according to claim 18, wherein the reference detector further comprises a reference in-phase detector for measuring reference in-phase components of the reference signal and a reference quadrature detector for measuring reference quadrature components of the reference signal.

21. A method for detecting an amount of cell destruction using an electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode, the method comprising the steps of:

(a) measuring a baseline impedance across a pair of leads of the electrodes with an impedance monitoring circuit when the leads are applied to an area of cell tissue before a cutting operation, a coagulation operation or a stimulating operation;

(b) implementing a selected operation, the selected operation selected to be the cutting operation, the coagulation operation or the stimulating operation;

(c) measuring a present impedance across the pair of leads of the electrodes with the impedance monitoring circuit during the selected operation of step (b);

(d) determining the amount of cell destruction which has occurred by comparing the present impedance to the baseline impedance, a difference between the impedances being correspondingly proportional to the amount of cell destruction caused by the generator apparatus; and

(e) stopping the selected operation after a predetermined level of cell destruction.

22. The method according to claim 21, wherein step (a) further includes measuring overall signal in-phase components using a bridge in-phase detector and overall signal quadrature components using a bridge quadrature detector and measuring reference signal in-phase components using a reference in-phase detector and reference signal quadrature components using a reference quadrature detector.

23. The method according to claim 22, wherein step (a) further includes combining the overall in-phase components and the overall quadrature components, combining the reference in-phase components and the reference quadrature components, comparing the overall components to the reference components to create a comparison result, in order to determine the magnitude and angle of an impedance.

24. A method for measuring impedance using an electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode, the method comprising the steps of:

(a) measuring an impedance across a pair of leads of the electrodes with an impedance monitoring circuit when the leads are applied to an area of tissue, the impedance monitoring circuit including a bridge in-phase detector, a bridge quadrature detector, a reference in-phase detector and a reference quadrature detector;

(b) measuring overall signal in-phase components using the bridge in-phase detector and overall signal quadrature components using the bridge quadrature detector;

(c) measuring reference signal in-phase components using the reference in-phase detector and reference signal quadrature components using the reference quadrature detector;

(d) combining the overall in-phase components and the overall quadrature components;

(e) combining the reference in-phase components and the reference quadrature components;

(f) comparing the combined overall components to the combined reference components to determine the magnitude and angle of the impedance.

25. A method for storing user-defined parameters using an electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode and having a controller, memory and an user interface, the method comprising the steps of:

(a) entering a first user-defined set-up parameter using the user interface;

(b) storing the first user-defined set-up parameter in a first memory location in the memory using a program in the controller; and

(c) selecting the first user-defined parameter using the user interface.

26. The method according to claim 25 further comprising the steps of:

(d) entering a second user-defined set-up parameter using the user interface;

(e) storing the second user-defined set-up parameter in a second memory location in the memory using a program in the controller; and

(f) selecting either the first user-defined set-up parameter or the second user-defined set-up parameter using the user interface.

27. The method according to claim 25, wherein the first user-defined set-up parameter is one of a pulse width setting, a frequency setting, a voltage setting, an amperage setting, a temperature limit, a time duration and an alarm setting.

28. A method of controlling an electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus operating in a cut mode, a coagulation mode or a stimulate mode and having a controller, memory and a user interface, the method comprising the steps of:

(a) setting a temperature setpoint;

(b) setting a soak time preset;

(c) measuring the actual temperature at the electrodes;

(d) comparing the actual temperature to the temperature setpoint and controlling an output power of the generator apparatus using an algorithm stored in the memory;

(e) determining when the actual temperature is approximately equal to the temperature setpoint;

(f) starting a timer that compares an elapsed time to the soak time preset; and

(g) reducing the power of the output signal to the electrodes to approximately zero.