Surgical generator for ultrasonic and electrosurgical devices

• US 9,050,093 B2
• Filed: 10/01/2010
• Issued: 06/09/2015
• 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: Aldridge, Jeffrey L., Killinger, Scott B., Davison, Mark A.
• Primary Examiner(s): Stoklosa, Joseph
• Assistant Examiner(s): Ram, Jocelyn D
• Application Number:
  US12/896,467
• Publication Number:
  US 20110087215A1
• Time in Patent Office: 1,712 Days
• Field of Search: 606/34, 606/38, 606/42
• US Class Current: 1/1
• 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 to control electrical power provided to tissue via first and second electrodes may comprise providing a drive signal to the tissue via the first and second electrodes and modulating a power provided to the tissue via the drive signal based on a sensed tissue impedance according to a first power curve. The first power curve may define, for each of a plurality of potential sensed tissue impedances, a first corresponding power. The methods may also comprise monitoring a total energy provided to the tissue via the first and second electrodes. When the total energy reaches a first energy threshold, the methods may comprise determining whether an impedance of the tissue has reached a first impedance threshold. The methods may further comprise, conditioned upon the impedance of the tissue failing to reach the first impedance threshold, modulating the power provided to the tissue via the drive signal based on the sensed tissue impedance according to a second power curve. The second power curve may define, for each of the plurality of potential sensed tissue impedances, a second corresponding power.

Claims

1. A method for controlling power provided to tissue via first and second electrodes, the method comprising:

providing a drive signal to the tissue via the first and second electrodes;

modulating the drive signal according to a first power curve, wherein the first power curve defines a first corresponding power level for each of a plurality of potential tissue impedances, and wherein the modulating comprises;

receiving an indication of a first tissue impedance value sensed between the first and second electrodes;

determining the first corresponding power level defined by the first power curve for the first tissue impedance value; and

modifying the drive signal to provide the first corresponding power level defined by the first power curve for the first tissue impedance value to the tissue;

monitoring a total energy provided to the tissue via the first and second electrodes;

when the total energy reaches a first energy threshold, determining whether an impedance of the tissue has reached a first impedance threshold; and

conditioned upon the impedance of the tissue failing to reach the first impedance threshold, modulating the drive signal according to a second power curve, wherein the second power curve defines a second corresponding power level for each of the plurality of potential tissue impedances, and wherein modulating the drive signal according to the second power curve comprises;

receiving an indication of a second tissue impedance value sensed between the first and second electrodes;

determining the second corresponding power level defined by the second power curve for the second tissue impedance value; and

modifying the drive signal to provide the second corresponding power level defined by the second power curve for the second tissue impedance value.

2. The method of claim 1, wherein the first corresponding power level is less than the second corresponding power level for at least half of the plurality of potential tissue impedances.

3. The method of claim 1, wherein a sum of the first corresponding power level over the plurality of potential tissue impedances is less than a sum of the second corresponding power level over the plurality of potential tissue impedances.

4. The method of claim 1, further comprising:

while modulating the drive signal according to the second power curve, when the total energy reaches a second energy threshold, determining whether the impedance of the tissue has reached the first impedance threshold; and

conditioned upon the impedance of the tissue failing to reach the first impedance threshold, modulating the drive signal according to a third power curve, wherein the third power curve defines a third corresponding power level for each of the plurality of potential tissue impedances.

5. The method of claim 4, wherein the second corresponding power level is less than the third corresponding power level for at least half of the plurality of potential tissue impedances.

6. The method of claim 1, further comprising:

while modulating the drive signal according to the second power curve, when the total energy reaches a second energy threshold, determining whether the sensed tissue impedance has reached a second impedance threshold; and

conditioned upon the impedance of the tissue failing to reach the second impedance threshold, modulating the drive signal according to a third power curve, wherein the third power curve defines a third corresponding power level for each of the plurality of potential tissue impedances.

7. The method of claim 1, wherein the first impedance threshold is a predetermined tissue impedance.

8. The method of claim 1, wherein the first impedance threshold is a predetermined tissue impedance rate of change.

9. The method of claim 1, wherein the first impedance threshold is based on both a predetermined tissue impedance and a predetermined tissue impedance rate of change.

10. The method of claim 1, wherein modulating the drive signal according to the first power curve comprises at least one action selected from the group consisting of:

modulating a current level of the drive signal;

modulating a voltage level of the drive signal; and

modulating a duty cycle of the drive signal.

11. The method of claim 1, wherein for each of the plurality of potential tissue impedances, the second corresponding power is equal to the first corresponding power multiplied by a constant.

12. The method of claim 1, further comprising terminating the provision of energy to the tissue when a termination threshold is reached.

13. The method of claim 12, wherein the termination threshold is based on a power curve.

14. 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 surgical system to;

provide a drive signal to tissue via first and second electrodes;

modulate the drive signal according to a first power curve, wherein the first power curve defines a first corresponding power level for each of a plurality of potential tissue impedances, and wherein the modulating comprises;

receiving an indication of a first tissue impedance value sensed between the first and second electrodes; and

determining the first corresponding power level defined by the first power curve for the first tissue impedance value;

modifying the drive signal to provide the first corresponding power level defined by the first power curve for the first tissue impedance value to the tissue;

monitor a total energy provided to the tissue via the first and second electrodes;

when the total energy reaches a first energy threshold, determine whether an impedance of the tissue has reached a first impedance threshold; and

conditioned upon the impedance of the tissue failing to reach the first impedance threshold, modulate the drive signal according to a second power curve, wherein the second power curve defines a second corresponding power level for each of the plurality of potential tissue impedances, and wherein the modulating comprises;

receiving an indication of a second tissue impedance value sensed between the first and second electrodes;

determining the second corresponding power level defined by the second power curve for the second tissue impedance value; and

modifying the drive signal to provide the second corresponding power level defined by the second power curve for the second tissue impedance value.

15. The surgical system of claim 14, wherein the surgical system further comprises a surgical device in communication with the generator, wherein the surgical device comprises the first and second electrodes.

16. A method for controlling power provided to tissue via first and second electrodes, the method comprising:

providing a drive signal to the tissue via the first and second electrodes;

determining a power to be provided to the tissue, wherein the determining comprises;

receiving an indication of a sensed tissue impedance;

determining a first corresponding power for the sensed tissue impedance according to a power curve, wherein the power curve defines a corresponding power for each of a plurality of potential sensed tissue impedances; and

multiplying the corresponding power by a multiplier, resulting in a scaled power;

modulating the drive signal to provide the scaled power to the tissue; and

conditioned upon the impedance of the tissue failing to reach a first impedance threshold, increasing the multiplier as a function of total energy provided to the tissue.

17. The method of claim 16, further comprising conditioned upon the impedance of the tissue reaching the first impedance threshold, maintaining the multiplier.

18. The method of claim 16, further comprising continuing to apply energy without modifying the multiplier until a termination threshold is reached.

19. The method of claim 18, wherein the termination threshold is based at least in part on a value of the multiplier.

20. The method of claim 16, wherein modulating the drive signal to provide the scaled power to the tissue comprises at least one action selected from the group consisting of:

modulating a current level of the drive signal;

modulating a voltage level of the drive signal; and

modulating a duty cycle of the drive signal.

21. The method of claim 16, wherein the first impedance threshold is a predetermined tissue impedance.

22. The method of claim 16, wherein the first impedance threshold is a predetermined tissue impedance rate of change.

23. The method of claim 16, wherein the first impedance threshold is based on both a predetermined tissue impedance and a predetermined tissue impedance rate of change.

24. 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 surgical system to;

provide a drive signal to the tissue via first and second electrodes;

determine a power to be provided to the tissue, wherein the determining comprises;

receiving an indication of a sensed tissue impedance;

determining a first corresponding power for the sensed tissue impedance according to a power curve, wherein the power curve defines a corresponding power for each of a plurality of potential sensed tissue impedances; and

multiplying the corresponding power by a multiplier, resulting in a scaled power;

modulate the drive signal to provide the scaled power to the tissue; and

conditioned upon the impedance of the tissue failing to reach a first impedance threshold, increase the multiplier as a function of the total energy provided to the tissue.

25. The surgical system of claim 24, wherein the surgical system further comprises a surgical device in communication with the generator, wherein the surgical device comprises the first and second electrodes.

26. A method for controlling power provided to tissue via first and second electrodes, the method comprising:

providing a drive signal to the tissue via the first and second electrodes;

determining a power to be provided to the tissue, wherein the determining comprises;

receiving an indication of a sensed tissue impedance;

determining a first corresponding power for the sensed tissue impedance according to a power curve, wherein the power curve defines a corresponding power for each of a plurality of potential sensed tissue impedances; and

multiplying the corresponding power by a first multiplier to find a scaled power;

modulating the drive signal to provide the scaled power to the tissue;

monitoring a total energy provided to the tissue via the first and second electrodes;

when the total energy reaches a first energy threshold, determining whether the impedance of the tissue has reached a first impedance threshold; and

conditioned upon the impedance of the tissue not reaching the first impedance threshold, increasing the first multiplier by a first amount.

27. The method of claim 26, further comprising:

when the total energy reaches a second energy threshold, determining whether the impedance of the tissue has reached a second impedance threshold; and

conditioned upon the impedance of the tissue not reaching the second impedance threshold, increasing the first multiplier by a second amount.

28. The method of claim 26, wherein the first impedance threshold is a predetermined tissue impedance.

29. The method of claim 26, wherein the first impedance threshold is a predetermined tissue impedance rate of change.

30. The method of claim 26, wherein the first impedance threshold is based on both a predetermined tissue impedance and a predetermined tissue impedance rate of change.

31. The method of claim 26, wherein modulating the drive signal comprises at least one action selected from the group consisting of:

modulating a current level of the drive signal;

modulating a voltage level of the drive signal; and

modulating a duty cycle of the drive signal.

32. 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 surgical device to;

provide a drive signal to tissue via first and second electrodes;

determine a power to be provided to the tissue, wherein the determining comprises;

receiving an indication of a sensed tissue impedance;

determining a first corresponding power for the sensed tissue impedance according to a power curve, wherein the power curve defines a corresponding power for each of a plurality of potential sensed tissue impedances; and

multiplying the corresponding power by a first multiplier to find a scaled power;

modulate the drive signal to provide the scaled power to the tissue;

monitor a total energy provided to the tissue via the first and second electrodes;

when the total energy reaches a first energy threshold, determine whether the impedance of the tissue has reached a first impedance threshold; and

conditioned upon the impedance of the tissue not reaching the first impedance threshold, increase the first multiplier by a first amount.

33. The surgical system of claim 32, wherein the surgical system further comprises a surgical device in communication with the generator, wherein the surgical device comprises the first and second electrodes.