Return electrode temperature prediction

• US 8,784,410 B2
• Filed: 03/04/2013
• Issued: 07/22/2014
• Est. Priority Date: 09/29/2009
• Status: Expired due to Fees

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Dunning, James E.
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): Ram, Jocelyn D
• Application Number:
  US13/784,202
• Publication Number:
  US 20130184701A1
• Time in Patent Office: 505 Days
• Field of Search: 606/32, 606/34, 606/35, 607/152
• 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. An electrosurgical generator for supplying electrosurgical energy to tissue, the electrosurgical generator comprising:

sensor circuitry configured to determine at least one of a characteristic of a patient or a tissue temperature at a return electrode pad site;

a processing device configured to calculate a constant relative to patient tissue type and determine a maximum temperature of tissue based on the constant relative to patient tissue type at the return electrode pad site; and

a controller configured to regulate output of the electrosurgical generator based on the at least one characteristic of a patient and the determined maximum temperature.

2. The electrosurgical generator according to claim 1, wherein the processing device is configured to calculate the maximum temperature based on the at least one characteristic of a patient and an impedance value of at least one electrode.

3. The electrosurgical generator according to claim 1, wherein the controller is configured to adjust the output of the electrosurgical generator to a predetermined level based on the determined maximum temperature.

4. The electrosurgical generator according to claim 1, wherein the type of return electrode pad is determined automatically.

5. The electrosurgical generator according to claim 1, wherein variables from a look-up table are loaded into the electrosurgical generator and automatically adjusts the energy based on the type of return electrode pad.

6. The electrosurgical generator 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 patient tissue type;

calculating a maximum temperature utilizing the constant relative to 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.