RETURN ELECTRODE TEMPERATURE PREDICTION

• US 20130184701A1
• Filed: 03/04/2013
• Published: 07/18/2013
• Est. Priority Date: 09/29/2009
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: DUNNING, JAMES E.
• Granted Patent: US 8,784,410 B2
• Time in Patent Office: Days
• US Class Current: 606/35
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61B 2018/00875 Resistance or impedance

Abstract

The present disclosure relates to an electrosurgical generator for supplying electrosurgical energy to tissue and methods thereof. The electrosurgical generator includes sensor circuitry, a processing device, and a controller. The type of return electrode pad may be determined automatically. The sensor circuitry is configured to determine one or more characteristics of a patient and/or measure tissue temperature at a return electrode pad site. The processing device is configured to determine a maximum temperature of tissue and calculate real-time predicted temperature at the return electrode pad site. The controller is configured to regulate output of the electrosurgical generator based on one or more characteristics of a patient and the determined maximum temperature.

Claims

1. A method for controlling an electrosurgical generator, the method comprising:

determining tissue temperature at a return electrode pad site;

calculating a maximum temperature of tissue at the return electrode pad site based on at least one characteristic of a patient; and

regulating output of an electrosurgical generator based on the tissue temperature and the determined maximum temperature.

2. The method according to claim 1, further comprising:

measuring impedance at the at least one return electrode pad; and

determining the at least one characteristic of the patient based on the measured impedance.

3. The method according to claim 1, further comprising:

adjusting the output of the electrosurgical generator to a predetermined level based on the calculated maximum temperature.

4. The method according to claim 1, further comprising:

determining a type of the at least one return electrode pad.

5. The method according to claim 4, further comprising:

loading at least one variable relating to the output of the electrosurgical generator from a look-up table into the electrosurgical generator based on the type of the at least one return electrode pad; and

adjusting the output of the electrosurgical generator based on the at least one variable.

6. The method according to claim 1, wherein the at least one characteristic of the patient is selected from the group consisting of sex, body weight, body mass index, and body fat percentage.

7. A method for calculating a maximum temperature at a return electrode pad site, the method comprising the steps of:

determining at least one characteristic of a patient and calculating a constant relative to a patient tissue type;

calculating a maximum temperature utilizing the constant relative to the patient tissue type at the return electrode pad site;

applying energy to tissue at a surgical site;

measuring a real-time temperature of tissue at the return electrode pad site and calculating a difference between the real-time temperature and the maximum temperature; and

adjusting the energy according to the difference between the real-time temperature and the maximum temperature.

8. The method according to claim 7, further comprising the step of:

determining a type of a return electrode pad adapted to be placed on tissue at the return electrode pad site based on the constant relative to patient tissue type.

9. The method according to claim 8, wherein the type of return electrode pad is determined automatically.

10. The method according to claim 9, wherein variables from a look-up table are loaded into an energy source that supplies energy to tissue and automatically adjusts the energy based on the type of return electrode pad.

11. The method according to claim 7, wherein the at least one characteristic of a patient is selected from the group consisting of sex, body weight, body mass index, and body fat percentage.