Linear power control with PSK regulation

• US 6,309,386 B1
• Filed: 10/06/1998
• Issued: 10/30/2001
• Est. Priority Date: 10/06/1997
• Status: Expired due to Fees

• Current Assignee: Somnus Medical Technologies, Inc. (Olympus Corporation)
• Original Assignee: Somnus Medical Technologies, Inc. (Olympus Corporation)
• Inventors: Bek, Robin B.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): Ruddy, David M.
• Application Number:
  US09/167,412
• Time in Patent Office: 1,120 Days
• Field of Search: 606/32, 606/34, 606/35, 606/36, 606/38, 606/40, 606/41, 606/42, 606/45, 606/46, 606/48, 606/50, 607/97, 607/101, 607/122
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 2017/00482 with a code
• CPC Class Codes: A61B 2018/00178 Electrical connectors
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/0075 Phase
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00827 Current
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00892 Voltage
• CPC Class Codes: A61B 2018/00988 Means for storing information, e.g. calibration constants, or for preventing excessive use, e.g. usage, service life counter
• CPC Class Codes: A61B 2018/1273 including multiple generators in one device
• CPC Class Codes: Y10S 128/923 by comparison of patient data to other data

Abstract

It is an object of the present invention to provide a multi-channel radio frequency (RF) power delivery and control system for applying energy to multiple electrodes of an RF tissue heating device.

In a first embodiment of the invention an apparatus for controlling electrical cross-talk in an electro-surgical instrument is disclosed. The apparatus includes: a driver, a first electrode, a second electrode, a ground for delivery of power to a surgical site, a power measurement circuit and a waveform generator. The power measurement circuit computes differences between a target power and an actual power delivered to the first electrode and the second electrode to establish an amount by which to increase and to decrease the power emanating from the first electrode and the second electrode. The waveform generator modulates a driver signal generated by the driver to increase and to decrease an integer number of whole wavelengths of the driver signal to produce a first oscillating signal measured at the first electrode and a second oscillating signal measured at the second electrode.

In an alternate embodiment of the invention a method for power control in an electro-surgical instrument is disclosed.

Claims

1. A method for power control in an electro-surgical instrument including a driver, and at least one electrode and a ground for delivery of power in the form of a first oscillating signal to a surgical site, and the method for power control comprising the acts of:

computing differences between a target power and an actual power delivered to the at least one electrode to establish an amount by which to increase and to decrease the power in the first oscillating signal; and

modulating a driver signal generated by the driver to increase and to decrease an integer number of whole wavelengths of the driver signal to produce the first oscillating signal, responsive to said computing act.

2. The method of claim 1, wherein said modulating act further comprises the act of:

switchable decoupling the at least one electrode from the driver signal to decrease by the integer number of the whole wavelengths the first oscillating signal.

3. The method of claim 1, wherein said modulating act further comprises the act of:

establishing a control interval corresponding to a first integer number of characteristic wavelengths of the driver signal;

implementing an active interval in the first oscillating signal in which the first oscillating signal corresponds with the driver signal;

implementing a null interval in the first oscillating signal by decoupling the driver signal from the electrode.

4. The method of claim 1, wherein the decoupling in said act of implementing a null interval results in said first oscillating signal exhibiting a null level.

5. A method for power control in an electro-surgical instrument including a driver, a first electrode and a second electrode and a ground for delivery of power to a surgical site, and the method for power control comprising the acts of:

computing differences between a target power and an actual power delivered to the first electrode and the second electrode to establish an amount by which to increase and to decrease the power emanating from the first electrode and the second electrode; and

modulating a driver signal generated by the driver to increase and to decrease an integer number of whole wavelengths of the driver signal to produce a first oscillating signal measured at the first electrode and a second oscillating signal measured at the second electrode, responsive to said computing act.

6. The method of claim 5, wherein said modulating act further comprises the act of:

switchably decoupling the first electrode from the driver signal to decrease by the integer number of the whole wavelengths the first oscillating signal, to avoid an electrical crosstalk between the second electrode and the first electrode; and

switchably decoupling the second electrode from the driver signal to decrease by the integer number of the whole wavelengths the second oscillating signal to avoid an electrical crosstalk between the first electrode and the second electrode.

7. The method of claim 5, wherein said modulating act further comprises the act of:

establishing a control interval corresponding to a first integer number of characteristic wavelengths of the driver signal;

implementing active intervals in the first oscillating signal and the second oscillating signal in which the first oscillating signal and the second oscillating signal correspond with the driver signal; and

implementing null intervals in the first oscillating signal and the second oscillating signal by decoupling the driver signal from the electrode.

8. The method of claim 5, wherein the decoupling in said act of implementing null intervals results in the first oscillating signal and the second oscillating signal exhibiting a null level.

9. The method of claim 5, wherein the decoupling in said act of implementing null intervals reduces an electrical crosstalk between the first electrode and the second electrode.

10. The method of claim 5, wherein the first oscillating signal and the second oscillating signal are phase synchronous.

11. An apparatus for controlling electrical cross-talk in an electro-surgical instrument including a driver, a first electrode and a second electrode and a ground for delivery of power to a surgical site, and the apparatus for controlling cross-talk comprising:

a power measurement circuit for computing differences between a target power and an actual power delivered to the first electrode and the second electrode to establish an amount by which to increase and to decrease the power emanating from the first electrode and the second electrode; and

a waveform generator coupled to a power drive and an isolation switchs the waveform generator modulating a driver signal generated by the power drive to increase and to decrease an integer number of whole wavelengths of the driver signal to produce a first oscillating signal measured at the first electrode and a second oscillating signal measured at the second electrode.

12. The apparatus of claim 11, wherein the isolation switch decouples the first electrode from the driver signal to decrease by the integer number of the whole wavelengths the first oscillating signal, to avoid an electrical crosstalk between the second electrode and the first electrode;

and for switchably decoupling the second electrode from the driver signal to decrease by the integer number of the whole wavelengths the second oscillating signal to avoid an electrical crosstalk between the first electrode and the second electrode.

13. The apparatus of claim 11, further comprising:

a timer for establishing a control interval corresponding to a first integer number of characteristic wavelengths of the driver signal;

a logic unit for implementing active intervals in the first oscillating signal and the second oscillating signal in which the first oscillating signal and the second oscillating signal correspond with the driver signal; and

implementing null intervals in the first oscillating signal and the second oscillating signal by decoupling the driver signal from the electrode.

14. The apparatus of claim 11, wherein the decoupling results in the first oscillating signal and the second oscillating signal exhibiting a null level.

15. The apparatus of claim 11, wherein the decoupling reduces an electrical crosstalk between the first electrode and the second electrode.

16. The apparatus of claim 11, wherein the first oscillating signal and the second oscillating signal are phase synchronous.