Electrocautery method and apparatus

Patent metadata

Field	Value
Publication number	US-10314642-B2
Application number	US-41032209-A
Country	US
Kind code	B2
Filing date	Mar 24, 2009
Priority date	May 12, 2005
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An electrode structure and a mechanism for automated or user-selected operation or compensation of the electrodes, for example to determine tissue coverage and/or prevent arcing between bottom electrodes during electrocautery is disclosed.

First claim

The invention claimed is:

1. An electrocautery apparatus, comprising:
a first electrode surface comprising a plurality of first electrodes, wherein at least one of the plurality of first electrodes is arranged so as to be substantially contiguous with at least one other of the plurality of the first electrodes;
a second electrode surface comprising at least one second electrode, the at least one second electrode opposite facing the plurality of first electrodes;
a power supply having at least one adjustable output channel for application of high frequency power to targeted tissue via selective coupling of said high frequency power to said plurality of first electrodes and to said at least one second electrode;
at least one sensor for sensing at least one first parameter comprising any of voltage, current, impedance, phase angle between applied voltage and current, temperature, energy, and frequency and for producing an output representative of a value or rate of change of said at least one first parameter;
a controller configured to control at least one aspect of said high frequency power provided by said power supply based on the output of the at least one sensor, the controller configured to selectively apply said high frequency power from said power supply between more than one of said plurality of first electrodes and said at least one second electrode, and during the selective application, the controller implementing a firing order for the more than one of said plurality of first electrodes which applies the high frequency power to the at least one of the plurality of first electrodes and the at least one other of the plurality of first electrodes neither concurrently nor sequentially;
wherein said high frequency power provided by said power supply cauterizes or necroses tissue between surfaces of said plurality of first electrodes and said at least one second electrode.

2. The apparatus of claim 1 , wherein said power supply is adjustable by any of real-time control, pre-set selection by a user, default settings, or selection of a predetermined profile.

3. The apparatus of claim 2 , said power supply comprising:
an RF generator selectively operable by the controller to insert a conjugate impedance in the form of an inductance to cancel out capacitive reactance with one of the plurality of first electrodes that is fully covered by tissue, and to permit measurement of phase-angle of RF voltage and current.

4. The apparatus of claim 3 , further comprising:
means for maintaining an impedance match between said RF generator and tissue;
wherein impedance matching is achieved when a phase-angle is about zero.

5. The apparatus of claim 4 , said means for maintaining an impedance match between said RF generator and tissue further comprising:
one or more reactive elements which compensate for increased capacitive reactance.

6. The apparatus of claim 5 , said means for maintaining an impedance match between said RF generator and tissue further comprising any of:
means for insertion of a continuously variable inductor with a finite range and nearly infinite resolution, wherein said inductor adjustable to a near zero phase;
means for insertion of discrete elements to find a lowest phase;
and means for changing the frequency of said RF generator, wherein said RF generator compensates for phase discrepancy by electronically changing frequency.

7. The apparatus of claim 2 , the controller further comprising:
an RF generator control algorithm for changing a frequency of the high frequency power upon detection of smaller surface areas of contact between the plurality of first electrodes and the tissue to maintain maximum power transfer while minimizing electrical arcing and suboptimal and/or excessive energy delivery.

8. The apparatus of claim 7 ,
wherein the controller is configured to detect electrical arcing and preventing suboptimal or excessive energy delivery based on rapid changes in the phase angle or the impedance sensed by the at least one sensor.

9. The apparatus of claim 8 , wherein the controller is configured to use any of the first and second electrodes which are only partially covered by tissue to signal said RF generator control algorithm to shorten or change the at least one first parameter.

10. The apparatus of claim 1 ,
wherein the at least one sensor senses the phase angle between applied voltage and current, and the controller is configured to determine the area of tissue coverage of said plurality of first electrodes and said at least one second electrode based on the phase angle between applied voltage and current.

11. The apparatus of claim 1 , said power generating high frequency power in frequency bands comprising any of 100 kHz to 10 MHz or 200 kHz to 750 kHz.

12. The apparatus of claim 1 , said power generating high frequency power at power levels comprising any of 10 W to 500 W, or 25 W to 250 W, or 50 W to 200 W.

13. The apparatus of claim 1 , said power supplying high frequency power to said plurality of first electrodes and said at least one second electrode at power levels comprising any of 1 W/cm 2 to 500 W/cm 2 or 10 W/cm 2 to 100 W/cm 2 .

14. The apparatus of claim 1 , said sensor comprising any of:
a voltmeter, analog-to-digital converter, thermistor, transducer, or ammeter.

15. The apparatus of claim 1 , further comprising:
means for selecting impedance to maintain an impedance match between said power supply and said tissue to achieve maximum power transfer and to make accurate power measurements;
wherein impedance matching is achieved when the phase-angle between applied voltage and current is at or near zero.

16. The apparatus of claim 15 , further comprising:
an inductive element that is adjustable to a near zero phase angle to increase inductance and compensate for increased capacitive reactance.

17. The apparatus of claim 1 , said power supply comprising adjustment means for any of:
identifying the more than one of said plurality of first electrodes to be activated to focus energy of the more than one of said plurality of first electrodes on a specific region of tissue;
establishing a firing order for said more than one of said plurality of first electrodes, the firing order established such that the at least one of the plurality of first electrodes and the at least one other of the plurality of first electrodes are not fired concurrently or sequentially;
assessing or measuring magnitude of impedance to be used in compensating and/or impedance matching between said power supply and the plurality of first electrodes and said at least one second electrode; and
establishing at least one second parameter of electrical power to be applied in electrocautery, said second parameter comprising voltage, current, impedance, phase angle between applied voltage and current, temperature, energy, frequency, and/or rate of change of said at least one second parameter.

18. The apparatus of claim 1 , wherein said at least one sensor is constructed to provide raw data to the controller, and the controller is configured to analyze whether and how to adjust the impedance by changing the frequency of RF energy delivered by said power supply.

19. The apparatus of claim 1 ,
wherein the controller is configured to determine whether or not tissue is present at any one of the first and second electrodes at the beginning of a cauterization cycle by measuring the at least one first parameter sensed by the at least one sensor, and/or a rate of change of said at least one first parameter;
wherein,

Assignees

• Eder Joseph Charles
• Nordell Ii Benjamin Theodore
• Edelstein Peter Seth
• Nezhat Camran
• Kane Mark
• Aesculap Ag

Inventors

• Eder Joseph Charles
• Nordell Ii Benjamin Theodore
• Edelstein Peter Seth
• Nezhat Camran
• Kane Mark

Classifications

• A61B2018/00702

  Power or energy · CPC title

• A61B2018/00827

  Current · CPC title

• A61B2018/165

  Multiple indifferent electrodes · CPC title

• A61B2018/00791

  Temperature · CPC title

• A61B2018/00595

  Cauterization · CPC title