Surgical generator for ultrasonic and electrosurgical devices

• US 9,039,695 B2
• Filed: 10/01/2010
• Issued: 05/26/2015
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Giordano, James R., Killinger, Scott B.
• Primary Examiner(s): Stoklosa, Joseph
• Assistant Examiner(s): Ram, Jocelyn D
• Application Number:
  US12/896,451
• Publication Number:
  US 20110087214A1
• Time in Patent Office: 1,698 Days
• Field of Search: 606/34, 606/38, 606/42
• US Class Current: 606/38
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00482 with a code
• CPC Class Codes: A61B 2017/00486 Adaptors for coupling parts with incompatible geometries
• CPC Class Codes: A61B 2017/2934 arcuate shaped guiding means
• CPC Class Codes: A61B 2017/2936 Pins in guiding slots
• CPC Class Codes: A61B 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2017/320071 with articulating means for working tip
• CPC Class Codes: A61B 2017/320094 additional movable means performing clamping operation
• CPC Class Codes: A61B 2017/320095 with sealing or cauterizing means
• CPC Class Codes: A61B 2018/00178 Electrical connectors
• CPC Class Codes: A61B 2018/00601 Cutting
• CPC Class Codes: A61B 2018/0063 Sealing
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00684 using lookup tables
• CPC Class Codes: A61B 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/0072 : Current
• CPC Class Codes: A61B 2018/00732 : Frequency
• CPC Class Codes: A61B 2018/00767 : Voltage
• CPC Class Codes: A61B 2018/00779 : Power or energy
• CPC Class Codes: A61B 2018/00803 : with temperature prediction
• 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 2018/00994 : combining two or more different kinds of non-mechanical energy or combining one or more non-mechanical energies with ultrasound
• CPC Class Codes: H01R 2201/12 : for medicine and surgery
• CPC Class Codes: H10N 30/802 : Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for

Abstract

In accordance with various embodiments, methods for controlling electrical power provided to tissue via a surgical device may comprise providing a drive signal to a surgical device; receiving an indication of an impedance of the tissue; calculating a rate of increase of the impedance of the tissue; and modulating the drive signal to hold the rate of increase of the impedance greater than or equal to a predetermined constant.

Claims

1. A method for controlling electrical power provided to tissue via a surgical device, the method comprising:

providing a drive signal to the surgical device;

receiving an indication of an impedance of the tissue;

calculating a rate of increase of the impedance of the tissue; and

modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a first predetermined constant, wherein the modulating comprises increasing a power of the drive signal when the rate of increase of the impedance of the tissue is below the first predetermined constant.

2. The method of claim 1, further comprising modulating the drive signal to hold the rate of increase of the impedance of the tissue equal to the first predetermined constant.

3. The method of claim 1, further comprising:

determining a first total energy provided to the tissue via the surgical device at a first time;

conditioned upon the first total energy exceeding a first energy threshold, determining if the impedance of the tissue has reached a first impedance threshold; and

conditioned upon the tissue not having reached the first impedance threshold, modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a second predetermined constant, wherein the second predetermined constant is greater than the first predetermined constant.

4. The method of claim 3, further comprising:

determining a second total energy provided to the tissue via the surgical device at a second time;

conditioned upon the second total energy exceeding a second energy threshold, determining if the impedance of the tissue has reached a second impedance threshold; and

conditioned upon the tissue not having reached the second impedance threshold, modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a third predetermined constant, wherein the third predetermined constant is greater than the first predetermined constant.

5. The method of claim 1, further comprising:

modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to the first predetermined constant for a first predetermined time period; and

at an expiration of the first predetermined time period, modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a second predetermined constant.

6. The method of claim 5, wherein the second predetermined constant is greater than the first predetermined constant.

7. The method of claim 5, further comprising:

at an expiration of the first predetermined time period, modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to the second predetermined constant for a second predetermined time period; and

at an expiration of the second predetermined time period, modulating the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a third predetermined constant.

8. The method of claim 7, wherein the third predetermined constant is greater than the second predetermined constant.

9. The method of claim 7, wherein the third predetermined constant is less than the second predetermined constant.

10. The method of claim 1, wherein providing the drive signal comprises providing the drive signal to first and second electrodes, wherein the tissue is in electrical communication with the first and second electrodes.

11. A surgical system, the surgical system comprising:

a generator comprising at least one processor and operatively associated memory, wherein the memory comprises instructions that, when executed by the at least one processor, cause the generator to;

provide a drive signal to a surgical device;

receive an indication of an impedance of tissue;

calculate a rate of increase of the impedance of the tissue; and

modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a first predetermined constant, wherein the modulating comprises increasing a power of the drive signal when the rate of increase of the impedance of the tissue is below the first predetermined constant.

12. The system of claim 11, wherein the memory further comprises instructions that, when executed by the at least one processor, cause the generator to modulate the drive signal to hold the rate of increase of the impedance of the tissue equal to the first predetermined constant.

13. The system of claim 11, wherein the memory further comprises instructions that, when executed by the at least one processor, cause the generator to:

determine a first total energy provided to the tissue via the surgical device at a first time;

conditioned upon the first total energy exceeding a first energy threshold, determine if the impedance of the tissue has reached a first impedance threshold;

conditioned upon the tissue not having reached the first impedance threshold, modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a second predetermined constant, wherein the second predetermined constant is greater than the first predetermined constant.

14. The system of claim 13, wherein the memory further comprises instructions that, when executed by the at least one processor, cause the generator to:

determine a second total energy provided to the tissue via the surgical device at a second time;

conditioned upon the second total energy exceeding a second energy threshold, determine if the impedance of the tissue has reached a second impedance threshold; and

conditioned upon the tissue not having reached the second impedance threshold, modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a third predetermined constant, wherein the third predetermined constant is greater than the first predetermined constant.

15. The system of claim 11, wherein the memory further comprises instructions that, when executed by the at least one processor, cause the generator to:

modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to the first predetermined constant for a first predetermined time period; and

at an expiration of the first predetermined time period, modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a second predetermined constant.

16. The system of claim 15, wherein the second predetermined constant is greater than the first predetermined constant.

17. The system of claim 15, wherein the memory further comprises instructions that, when executed by the at least one processor, cause the generator to:

at an expiration of the first predetermined time period, modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to the second predetermined constant for a second predetermined time period; and

at an expiration of the second predetermined time period, modulate the drive signal to hold the rate of increase of the impedance of the tissue greater than or equal to a third predetermined constant.

18. The system of claim 17, wherein the third predetermined constant is greater than the second predetermined constant.

19. The system of claim 17, wherein the third predetermined constant is less than the second predetermined constant.

20. The system of claim 11, wherein providing the drive signal comprises providing the drive signal to first and second electrodes, wherein the tissue is in electrical communication with the first and second electrodes.