High frequency power source

Patent metadata

Field	Value
Publication number	US-9750557-B2
Application number	US-70386107-A
Country	US
Kind code	B2
Filing date	Feb 8, 2007
Priority date	Dec 28, 2000
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A high frequency electrosurgical power generator configured to produce electrical power at a frequency of about 1 to about 14 MHz and preferably having an essentially sinusoidal waveform with a voltage level up to 1,000 Vrms, and a current level up to 5 Amps. The output of the high frequency electrosurgical power generator is connected to an electrosurgical tool configured to receive the voltage and current produced by the electrosurgical power generator and deliver the voltage and current to an electrosurgical site. The output of the electrosurgical generator preferably is an essentially sinusoid waveform with a frequency between about 3 MHz and about 8 MHz, up to about 700 volts rms, up to about 2 amps, with a total power of up to 1,000 watts.

First claim

What is claimed is:

1. A method for controlling electrosurgical tissue cutting at a patient's site, comprising:
a. providing an electrosurgical cutting tool having a tissue cutting electrode with a distal tip and an exposed conductive length proximal to the distal tip that is configured to contact tissue;
b. providing a return electrode in contact with the patient's tissue remote from the patient's site;
c. providing an electrosurgical RF power generator in an electrical conductive relationship with the tissue cutting electrode and the return electrode;
d. contacting tissue with the exposed conductive length of the tissue cutting electrode;
e. generating RF energy as a waveform within the electrosurgical RF power generator and gating the RF energy to generate gated RF energy having a duty cycle of less than 100%;
f. delivering the gated RF energy from the electrosurgical RF power generator to the tissue cutting electrode so as to pass an electrical current from the exposed conductive length of the tissue cutting electrode to tissue in contact with the exposed conductive length of the tissue cutting electrode to form a steam layer between the tissue cutting electrode and the tissue by tissue desiccation and generate a conductive plasma along the exposed conductive length, and with the onset of the steam layer continued desiccation and cutting of the tissue is effected; and
g. regulating the electrosurgical RF power generator to maintain a voltage present at the tissue cutting electrode above a level needed to maintain formation of the steam layer by adjusting a gain of a voltage controlled amplifier in the electrosurgical RF power generator based at least in part on a voltage present at the electrosurgical cutting tool as well as a DC potential generated across a tool/tissue boundary of the electrosurgical cutting tool and the tissue.

2. The method of claim 1 wherein the electrosurgical RF power generator has a start mode when the voltage at the tissue cutting electrode is less than the level to cut tissue.

3. The method of claim 2 wherein the electrosurgical RF power generator has a sustaining mode when the voltage is at or exceeds the level to cut tissue.

4. The method of claim 1 wherein the exposed conductive length of the tissue cutting electrode has an arcuate shape.

5. The method of claim 4 wherein the arcuate shaped exposed conductive length of the tissue cutting electrode is moved to cut tissue by rotation.

6. A method for controlling an electrosurgical RF power generator for performing electrosurgical tissue cutting at a patient's site, comprising:
a. directly contacting tissue at the patient's site with an exposed conductive length of a tissue cutting electrode while a return electrode is in contact with the patient's tissue at a location that is remote from the patient's site, each of the tissue cutting electrode and the return electrode being in electrical communication with the electrosurgical RF power generator;
b. generating RF energy as a waveform within the electrosurgical RF power generator and gating the RF energy to generate gated RF energy;
c. delivering the gated RF energy from the electrosurgical RF power generator to the tissue cutting electrode so as to pass an electrical current from the exposed conductive length of the tissue cutting electrode to tissue in contact with the exposed conductive length of the tissue cutting electrode to form a steam layer between the tissue cutting electrode and the tissue by tissue desiccation and generate a conductive plasma along the exposed conductive length, and with the onset of the steam layer continued desiccation and cutting of the tissue is effected; and
d. regulating the electrosurgical RF power generator to maintain formation of the steam layer by adjusting a gain of a voltage controlled amplifier in the electrosurgical RF power generator based at least in part on a DC potential generated across a tool/tissue boundary of the electrosurgical cutting tool and the tissue at the patient's site.

7. A method for controlling an electrosurgical RF power generator for performing electrosurgical tissue cutting at a surgical site on a patient, comprising:
a. contacting tissue at the surgical site with an exposed conductive length of a tissue cutting electrode while a return electrode is in contact with the patient's tissue at a location that is remote from the surgical site, each of the tissue cutting electrode and the return electrode being in electrical communication with the electrosurgical RF power generator;
b. generating RF energy as a waveform within the electrosurgical RF power generator and gating the RF energy to generate gated RF energy;
c. delivering the gated RF energy from the electrosurgical RF power generator to the tissue cutting electrode so as to pass an electrical current from the exposed conductive length of the tissue cutting electrode to tissue in contact with the exposed conductive length of the tissue cutting electrode to form a steam layer between the tissue cutting electrode and the tissue by tissue desiccation and generate a conductive plasma along the exposed conductive length, and with the onset of the steam layer continued desiccation and cutting of the tissue is effected; and
d. regulating the electrosurgical RF power generator to maintain formation of the steam layer by adjusting a gain of a voltage controlled amplifier in the electrosurgical RF power generator based at least in part on a DC potential generated across a tool/tissue boundary of the electrosurgical cutting tool and the tissue at the patient's site.

Assignees

• Dabney James Huntington
• Quick Richard L
• Sawicz Conrad
• Lubock Paul
• Kussman Dan
• Senorx Inc

Inventors

• Dabney James Huntington
• Quick Richard L
• Sawicz Conrad
• Lubock Paul
• Kussman Dan

Classifications

• A61B2018/00702

  Power or energy · CPC title

• A61B2018/00607

  Coagulation and cutting with the same instrument · CPC title

• A61B2018/00892

  Voltage · CPC title

• A61B18/1233

  with circuits for assuring patient safety · CPC title

• A61B2018/0094

  Types of switches or controllers · CPC title