Self-limiting electrosurgical return electrode with pressure sore reduction and heating capabilities

• US 8,876,812 B2
• Filed: 02/10/2010
• Issued: 11/04/2014
• Est. Priority Date: 02/26/2009
• Status: Active Grant

• Current Assignee: Megadyne Medical Products Incorporated (Johnson & Johnson)
• Original Assignee: Megadyne Medical Products Incorporated (Johnson & Johnson)
• Inventors: Aramayo, Thomas F.
• Primary Examiner(s): Peffley, Michael
• Assistant Examiner(s): VAHDAT, KHADIJEH A
• Application Number:
  US12/703,475
• Publication Number:
  US 20100217260A1
• Time in Patent Office: 1,728 Days
• Field of Search: 606/32, 606/34, 606/35, 606/41
• US Class Current: 606/32
• CPC Class Codes: A61B 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61B 2018/167 Passive electrodes capacitively coupled to the skin
• CPC Class Codes: A61F 7/007 characterised by electric heating

Abstract

A self-limiting electrosurgical electrode for use with electrosurgery and various other surgical procedures is disclosed. The electrode includes a heating element for generating heat to warm a patient resting upon the electrode. The electrode can also include one or more pads to prevent the creation of pressure sores or decubitus ulcers on a patient resting upon the electrode. The electrode has an effective bulk impedance equal to or greater than about 4,000 Ω·cm, which arises from resistive components, capacitive components, inductive components, or combinations thereof. Through the selection of the impedance characteristics for the electrode materials, and through tailoring of electrode geometries, the electrode of the present invention is self-regulating and self-limiting as to current density and temperature rise so as to prevent patient trauma.

Claims

1. An electrosurgical electrode comprising:

one or more pads configured to substantially prevent the creation of one or more pressure sores on a patient resting upon said electrosurgical electrode, said one or more pads comprising at least one pad having a first side and an opposing second side;

a conductive element configured to conduct electrical current, said conductive element being positioned adjacent said first side of said at least one pad; and

a heating element comprising a heat generating element and a heat spreading element, said heat generating element being adapted to generate heat for warming a patient resting upon said electrosurgical electrode when an electrical current is passed through the heat generating element, the heat spreading element being configured to conduct the heat away from the heat generating element and evenly distribute the heat uniformly over a surface area of the electrosurgical electrode, said heat generating element being disposed within and coplanar with said heat spreading element, the heating element being positioned adjacent said opposing second side of said at least one pad such that said heating element and said conductive element are spaced apart from one another by said at least one pad,

wherein, said conductive element and said one or more pads have an effective bulk impedance equal to or greater than about 4,000 Ω

·

m.

2. The electrosurgical electrode according to claim 1, further comprising a thermal insulation layer positioned adjacent said heating element on a side of said heating element opposite to said at least one pad, said thermal insulation layer being adapted to direct the heat generated by said heating element towards said at least one pad.

3. The electrosurgical electrode according to claim 1, wherein the electrosurgical electrode comprises a top surface configured to have a patient rest thereon, wherein one of said one or more pads is positioned on top of said conductive element such that said pad is positioned between said conductive element and said top surface.

4. The electrosurgical electrode according to claim 1, wherein said one or more pads comprise a material selected from the group consisting of a visco-elastic material, a gel, water, saline, a water based material, a conductive oil, or combinations thereof.

5. The electrosurgical electrode according to claim 1, wherein said heating element is positioned near a bottom surface of said electrosurgical electrode.

6. The electrosurgical electrode according to claim 1, wherein said heating element comprises a fabric formed of conductive fibers.

7. The electrosurgical electrode according to claim 1, wherein said conductive element comprises normally insulating material impregnated with electrically conducting fibers to render said electrosurgical electrode to have an effective bulk impedance equal to or greater than about 4,000 Ω

·

cm.

8. The electrosurgical electrode according to claim 1, wherein said effective bulk impedance of said conductive element and said one or more pads comprises electrical components selected from the group consisting of resistance, capacitive, inductive, or combinations thereof.

9. The electrosurgical electrode according to claim 1, wherein said conductive element comprises:

an electrode, said electrode comprising;

a first layer of predetermined limited electrical conductivity; and

a second layer of dielectric material having a predetermined capacitive reactance, said second layer contacting and overlying said first layer.

10. An electrosurgical electrode for warming a patient resting upon the electrosurgical electrode and preventing the creation of pressure sores on the patient, the electrosurgical electrode comprising:

a conductive element configured to conduct electrical current, the conductive element having a first surface and an opposing second surface;

an electrical heating element comprising a heat generating element and heat spreading element, the heat generating element being adapted to convert electrical energy to heat energy and the heat spreading element being generally planar and substantially uniform, heat spreading element being adapted to conduct the heat energy away from the heat generating element and evenly distribute the heat energy uniformly so as to warm a patient resting upon said electrosurgical electrode, the electrical heating element having a first surface and an opposing second surface and said heat generating element being disposed within and coplanar with said heat spreading element; and

first and second pads adapted to substantially prevent the creation of one or more pressure sores on a patient resting upon said electrosurgical electrode, said first pad being positioned between said conductive element and said electrical heating element such that said first surface of said conductive element is positioned adjacent a first side of said first pad and said first surface of said electrical heating element is positioned adjacent an opposing second side of said first pad, and said second pad being positioned adjacent said opposing second surface of said conductive element such that said second pad is positioned between said conductive element and a patient resting upon said electrosurgical electrode,

wherein, said electrosurgical electrode has a collective bulk resistance equal to or greater than about 4,000 Ω

·

cm.

11. The electrosurgical electrode according to claim 10, wherein-said first pad is substantially thicker than said second pad.

12. The electrosurgical electrode according to claim 10, wherein at least one of said first and second pads is formed of a visco-elastic material.

13. The electrosurgical electrode according to claim 10, wherein at least one of said first and second pads is formed of a gel.

14. The electrosurgical electrode according to claim 10, wherein at least one of said first and second pads is formed of water, saline, a water based material, a conductive oil, or a combination thereof.

15. The electrosurgical electrode according to claim 10, wherein said first and second pads are thermally conductive.

16. The electrosurgical electrode according to claim 10, wherein said conductive element comprises electrically conducting material having an effective bulk resistivity equal to or greater than about 4,000 Ω

·

cm.

17. The electrosurgical electrode according to claim 10, wherein said first pad is between about 0.20″

and about 3.0″

thick.

18. The electrosurgical electrode according to claim 10, wherein said second pad is between about 0.05″

and about 0.50″

thick.

19. An electrosurgical electrode configured to be disposed beneath a patient during electrosurgery to provide a return path for an electrosurgical current used in electrosurgery, the electrosurgical electrode being self-limiting such that the electrosurgical current is limited to safe thresholds so as to prevent an undesirable patient burn at the contact area between the patient and the electrode in the event of an accidental reduction in the contact area below a threshold level, the electrosurgical electrode comprising:

a first cover layer and a second cover layer associated with one another to form an envelope with an interior portion;

a heating element comprising a heat generating element and a heat spreading element, the heating element being disposed within said interior portion, said heat generating element being adapted to generate heat, said heat spreading element being generally planar and substantially uniform, said heat spreading element being adapted to conduct the heat energy away from the heat generating element and evenly distribute the heat energy uniformly for warming the patient resting upon said electrosurgical electrode, said heat generating element being disposed within and coplanar with said heat spreading element;

a conductive element disposed within said interior portion of said envelope and above said heating element, said conductive element being configured to conduct electrical current;

first and second pads disposed within said interior portion, said first pad being positioned between said heating element and said conductive element, said second pad being positioned between said conductive element and said second cover layer, said first and second pads being adapted to substantially prevent the creation of one or more pressure sores on the patient resting on said electrosurgical electrode; and

a thermal insulation layer disposed between said first cover layer and said heating element such that said thermal insulation layer directs heat away from said first cover layer and toward said heating element and said conductive element,

wherein, the effective bulk impedance of said second pad and said conductive element is equal to or greater than about 4,000 Ω

·

cm.

20. The electrosurgical electrode according to claim 19, wherein said first and second pads are adapted to transfer the heat generated by said heating element to the patient resting on said electrosurgical electrode.

21. The electrosurgical electrode according to claim 19, wherein said heating element comprises electrically conductive fibers and at least one of wool, polyester, or an aramid.

22. The electrosurgical electrode according to claim 19, wherein said heating element comprises a carbon impregnated polymer.

23. The electrosurgical electrode according to claim 19, wherein said thermal insulation layer directs heat toward said second cover layer.

24. The electrosurgical electrode according to claim 19, wherein said thermal insulation layer is adapted to substantially prevent the creation of one or more pressure sores on the patient resting on said electrosurgical electrode.

25. The electrosurgical electrode according to claim 19, wherein said first pad is between about 0.20″

and about 3.0″

thick and said second pad is between about 0.05″ and

about 0.50″

thick.