Electrodes for sustained delivery of energy

• US 7,463,917 B2
• Filed: 06/07/2004
• Issued: 12/09/2008
• Est. Priority Date: 04/28/2004
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Martinez, Gonzalo
• Primary Examiner(s): Layno; Carl H
• Assistant Examiner(s): LEE, YUN H
• Application Number:
  US10/862,214
• Publication Number:
  US 20050246002A1
• Time in Patent Office: 1,646 Days
• Field of Search: 607/121, 600/372, 600/395
• US Class Current: 600/395
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61N 1/0476 Array electrodes (including any electrode arrangement with more than one electrode for at least one of the polarities)
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/306 Arrangements where at least part of the apparatus is introduced into the body

Abstract

Electrodes include a coating that provides a barrier to fluids and ions within a biological environment. The coating increases the overpotential of the electrode. The coating permits the introduction and use of the electrodes into biological environments without the detrimental complications of electro-chemical reactions typically present with the use of metal and metal-alloy electrodes in such environments.

Claims

1. An electrode comprising:

an electrically conductive, monolithic substrate layer;

an elongated electrical conductor having an insulating cover layer and coupled to the conductive substrate layer; and

an electrically non-insulating, coating layer covering the substrate layer, wherein the coating layer provides an increased overpotential for the electrode in a fluid.

2. The electrode according to claim 1, wherein the overpotential is increased relative to an equilibrium potential of a reference electrode.

3. The electrode according to claim 2, wherein the reference electrode is a saturated calomel electrode and the overpotential increase is at least approximately 1.2 volts.

4. The electrode according to claim 2, wherein the reference electrode is a saturated calomel electrode and the overpotential increase is at least approximately 1.8 volts.

5. The electrode according to claim 1, wherein the coating layer comprises a boron-doped diamond material having boron ions in a concentration of between 2,000 to 10,000 parts per million.

6. The electrode according to claim 1, wherein the coating layer includes a dopant and a material selected from the group consisting of:

diamond, diamond-like carbon, borosilicate glass, carbides, nitrides.

7. The electrode according to claim 1, wherein the coating layer includes a doped dielectric material.

8. The electrode according to claim 1, wherein the coating layer has a thickness between approximately 2 and 10 nm.

9. The electrode according to claim 1, wherein the coating layer has a thickness between approximately 1 and 100 nm.

10. The electrode according to claim 1, wherein the substrate layer comprises a plurality of electrode array elements.

11. The electrode according to claim 10, wherein the electrical conductor includes a plurality of electrical conductors, and each of the electrode array elements is separately coupled to a separate one of the electrical conductors.

12. The electrode according to claim 10, wherein each of the electrode array elements is individually actuable to generate an electric field independently of the other electrode array elements.

13. The electrode according to claim 1, wherein the electrically conductive substrate includes a metal.

14. The electrode according to claim 1, wherein the coating layer is sputtered or vapor deposited.

15. The device according to claim 14, further comprising an implantable component configured to deliver a therapy upon interaction with the electric field.

16. The device according to claim 1, wherein the implantable component includes a device that releases a therapeutic substance upon interaction with the electric field.

17. The device according to claim 16, wherein the therapeutic substance includes an injected, ingested, or inhaled substance.

18. A medical device comprising:

a first electrode having a first electrically conductive, monolithic substrate layer, a first elongated electrical conductor having an insulating cover layer and coupled to the first substrate layer, and a first non-insulating, coating layer covering the first substrate layer, wherein the first coating layer provides an increased overpotential for the first electrode in a fluid;

a second electrode having a second electrically conductive, monolithic substrate layer, a second elongated electrical conductor having an insulating cover layer and coupled to the conductive substrate layer, and a second electrically non-insulating coating layer covering the second substrate layer, wherein the second coating layer provides an increased overpotential for the second electrode in a fluid;

an electrical power source coupled to apply a substantially continuous electric potential across the first and second elongated electrical conductors.

19. The medical device of claim 18, wherein the electrical power source applies a substantially continuous electric potential of greater than or equal to approximately one volt across the first and second electrical conductors for a period of greater than or equal to approximately one second.

20. The device according to claim 18, wherein the overpotential is increased relative to an equilibrium potential of a reference electrode.

21. The device according to claim 18, wherein the reference electrode is a saturated calomel electrode and the overpotential increase is at least approximately 1.2 volts.

22. The device according to claim 18, wherein the reference electrode is a saturated calomel electrode and the overpotential increase is at least approximately 1.8 volts.

23. The device according to claim 18, wherein each of the first and second coating layers comprises a boron-doped diamond material having boron ions in a concentration of at between about 2,000 to 10,000 parts per million.

24. The device according to claim 18, wherein each of the first and second coating layers includes a dopant and a material selected from the group consisting of:

diamond, diamond-like carbon, borosilicate glass, carbides, nitrides.

25. The device according to claim 18, wherein each of the first and second coating layers includes a doped dielectric material that increases the overpotential by at least approximately 1.2 volts.

26. The device according to claim 18, wherein each of the first and second coating layers includes a doped dielectric material.

27. The device according to claim 18, wherein each of the first and second coating layers has a thickness between approximately 2 and 10 nm.

28. The device according to claim 18, wherein each of the first and second coating layers has a thickness between approximately 1 and 100 nm.

29. The device according to claim 18, wherein each of the first and second substrate layers comprises a plurality of electrode array elements.

30. The device according to claim 29, wherein each of the electrical conductors includes a plurality of electrical conductors, and each of the electrode array elements is separately coupled to a separate one of the electrical conductors.

31. The device according to claim 29, wherein each of the electrode array elements is individually actuable to generate an electric field independently of the other electrode array elements.

32. The device according to claim 18, wherein each of the first and second electrically conductive substrates includes a metal.

33. The device according to claim 18, wherein each of the first and second coating layers is sputtered or vapor deposited.

34. The device according to claim 18, wherein the electric potential is a time varying electric potential.

35. The device according to claim 18, wherein the electric potential is a non-time varying electric potential.

36. An electrode comprising:

an electrically conductive, monolithic substrate layer;

an elongated electrical conductor having an insulating cover layer and coupled to the conductive substrate layer; and

an electrically non-insulating, coating layer formed of a material comprising a boron dopant covering the substrate layer, wherein the coating layer provides an increased overpotential for the electrode in a fluid without substantially increasing an impedance of the electrode as compared to a coating layer formed of the material without a dopant.

37. An electrode comprising:

an electrically conductive, monolithic substrate layer;

an elongated electrical conductor having an insulating cover layer and coupled to the conductive substrate layer; and

an electrically non-insulating, coating layer formed of a material comprising a boron dopant covering the substrate layer, wherein the coating layer provides an increased overpotential for the electrode in a fluid.