System and method for return electrode monitoring

• US 9,539,051 B2
• Filed: 08/11/2014
• Issued: 01/10/2017
• Est. Priority Date: 08/01/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Gregg, William N., Rick, Kyle R.
• Primary Examiner(s): DELLA, JAYMI E
• Application Number:
  US14/456,851
• Publication Number:
  US 20140350546A1
• Time in Patent Office: 883 Days
• Field of Search: 606 34- 38
• US Class Current: 1/1
• 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 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/0072 Current
• CPC Class Codes: A61B 2018/00755 Resistance or impedance
• CPC Class Codes: A61B 2018/00827 Current
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/162 located on the probe body
• CPC Class Codes: A61B 2018/165 Multiple indifferent electrodes

Abstract

A system for determining probability of tissue damage includes a plurality of return electrodes adhered to a patient and adapted to couple to an electrosurgical generator configured to generate an electrosurgical current. The system also includes a current monitor and a switching component connected in series with each of the plurality of the return electrodes. The current monitor is configured to measure the electrosurgical current passing therethrough. The system further includes a processor coupled to each of the current monitors and the switching components. The processor is configured to determine the balance of a current load among the plurality of the return electrodes and configured to control each of the switching components to adjust the current passing through each of the return electrodes to balance the current load.

Claims

1. A method for determining probability of tissue damage, the method comprising:

coupling a plurality of return electrodes to a patient and to an electrosurgical generator that is configured to generate an electrosurgical current, wherein each of the plurality of return electrodes includes a current monitor and a switching component connected in series with each of the plurality of return electrodes;

measuring the electrosurgical current passing through each of the plurality of return electrodes;

determining a balance of a current load among the plurality of return electrodes, determining the balance of the current load including;

determining a current threshold based on a tolerance value of the plurality of return electrodes and a summation of the electrosurgical current passing through each of the plurality of return electrodes; and

determining whether the electrosurgical current passing through at least one of the plurality of return electrodes exceeds the determined current threshold; and

controlling each of the switching components to adjust the electrosurgical current passing through each of the plurality of return electrodes to balance the current load.

2. The method according to claim 1, wherein the switching components are controlled using a pulse width modulated control signal.

3. The method according to claim 1, wherein controlling each of the switching components further includes adjusting an impedance of at least one of the plurality of return electrodes.

4. The method according to claim 3, wherein each of the switching components is selected from the group consisting of a resistor network, a variable capacitor, and a transformer coupled load.

5. The method according to claim 1, wherein each of the switching components is selected from the group consisting of a relay and a transistor.

6. The method according to claim 1, wherein controlling each of the switching components further includes disconnecting at least one of the plurality of return electrodes.

7. The method according to claim 1, wherein each of the plurality of return electrodes is coupled to an impedance sensor.

8. A method for determining probability of tissue damage, the method comprising:

generating an electrosurgical current;

measuring the electrosurgical current passing through each of a plurality of return electrodes adhered to a patient;

determining a current threshold based on a tolerance value of the plurality of return electrodes and a summation of the electrosurgical current passing through each of the plurality of return electrodes; and

comparing the electrosurgical current passing through at least one of the plurality of return electrodes with the current threshold to determine whether the electrosurgical current passing through the at least one of the plurality of return electrodes exceeds the current threshold.

9. The method according to claim 8, further comprising adjusting the electrosurgical current passing through at least one of the plurality of return electrodes to balance an average current load.

10. The method according to claim 9, wherein adjusting the electrosurgical current to balance the average current load is based on comparing the electrosurgical current passing through the at least one of the plurality of return electrodes to the current threshold.

11. The method according to claim 9, wherein adjusting the electrosurgical current includes controlling a plurality of switching components, each of the plurality of switching components is connected to a respective one of the plurality of return electrodes.

12. The method according to claim 11, wherein controlling the plurality of switching components includes disconnecting at least one of the plurality of return electrodes.

13. The method according to claim 12, wherein disconnecting the at least one of the plurality of return electrodes occurs for a time-off period based on measuring of the electrosurgical current passing through each of the plurality of return electrodes.

14. The method according to claim 11, wherein controlling the plurality of switching components includes adjusting an impedance of at least one of the plurality of return electrodes.

15. The method according to claim 11, wherein each of the plurality of switching components is configured to operate via a pulse width modulated control signal.

16. The method according to claim 11, wherein each of the plurality of switching components is selected from the group consisting of a resistor network, a variable capacitor, a transformer coupled load, and combinations thereof.

17. The method according to claim 11, wherein each of the plurality of switching components is selected from the group consisting of a relay and a transistor.

18. The method according to claim 8, wherein each of the plurality of return electrodes is coupled to an impedance sensor.