Temperature monitoring return electrode

• US 20080281311A1
• Filed: 05/11/2007
• Published: 11/13/2008
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Dunning, James E., Gadsby, Peter, Gresback, David
• Granted Patent: US 8,388,612 B2
• Time in Patent Office: Days
• US Class Current: 606/32
• CPC Class Codes: A61B 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61B 2017/00101 using an array of thermosensors

Abstract

An electrosurgical return electrode includes a conductive pad including a patient-contacting surface configured to conduct electrosurgical energy, and a temperature sensing circuit coupled to the conductive pad. The temperature sensing circuit includes a plurality of switching elements connected in series, wherein each of the plurality of switching elements is configured to vary in impedance in response to temperature changes, such that an interrogation signal transmitted therethrough is indicative of the temperature change.

Claims

1. An electrosurgical return electrode, comprising:

a conductive pad including a patient-contacting surface configured to conduct electrosurgical energy; and

a temperature sensing circuit coupled to the conductive pad, the temperature sensing circuit including a plurality of switching elements connected in series, wherein each of the plurality of switching elements is configured to vary in impedance in response to temperature changes, such that an interrogation signal transmitted therethrough is indicative of the temperature change.

2. An electrosurgical return electrode according to claim 1, wherein each of the plurality of switching elements is a polymeric positive temperature coefficient overcurrent protection device.

3. An electrosurgical return electrode according to claim 1, wherein duration of the interrogation signal is adjusted in response to the temperature.

4. An electrosurgical return electrode, comprising:

a conductive pad including a patient-contacting surface configured to conduct electrosurgical energy; and

a temperature sensing circuit coupled to the conductive pad, the temperature sensing circuit including a thermocouple matrix having a first plurality of metallic wires and a second plurality of metallic wires intersecting at a plurality of junctions, wherein each of the junctions is adapted to be interrogated to obtain a respective temperature measurement.

5. An electrosurgical return electrode according to claim 4, wherein the first plurality of metallic wires are laid out in a first direction and the second plurality of metallic wires are laid out in a second direction substantially perpendicular to the first direction.

6. An electrosurgical return electrode according to claim 4, wherein the first plurality of metallic wires is formed from copper and the second plurality of metallic wires is formed from constantan.

7. An electrosurgical return electrode according to claim 4, further comprising a multiplexer configured to individually interrogate each of the junctions.

8. An electrosurgical return electrode, comprising:

a conductive pad including a patient-contacting surface configured to conduct electrosurgical energy; and

a temperature sensing circuit coupled to the conductive pad, the temperature sensing circuit including at least one temperature sensor coupled to a multiplexer, the temperature sensor having a predetermined forward voltage drop that is indicative of temperature of the conductive pad.

9. The electrosurgical return electrode of claim 8, wherein the temperature sensor is selected from the group consisting of a transistor, a diode, a thermocouple, and a thermistor.