Method of routing electrical current to bodily tissues via implanted passive conductors

• US 7,502,652 B2
• Filed: 01/23/2006
• Issued: 03/10/2009
• Est. Priority Date: 01/22/2004
• Status: Active Grant

• Current Assignee: 2249020 Alberta Limited
• Original Assignee: Rehabtronics, Inc.
• Inventors: Gaunt, Robert Andrew, Prochazka, Arthur
• Primary Examiner(s): Layno; Carl H
• Assistant Examiner(s): Behringer; Luther G
• Application Number:
  US11/337,824
• Publication Number:
  US 20060184211A1
• Time in Patent Office: 1,142 Days
• Field of Search: 600/391, 606/32, 607/2, 607/45, 607/46, 607/48, 607/60, 607/142, 607/152, 607/28, 607/49, 607/118, 623/11.11
• US Class Current: 607/46
• CPC Class Codes: A61B 5/0028 Body tissue as transmission medium, i.e. transmission systems where the medium is the human body
• CPC Class Codes: A61B 5/4029 for evaluating the peripheral nervous systems A61B5/24 takes precedence
• CPC Class Codes: A61B 5/4082 Diagnosing or monitoring movement diseases, e.g. Parkinson, Huntington or Tourette
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• 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 1/0504 Subcutaneous electrodes
• CPC Class Codes: A61N 1/0556 Cuff electrodes
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36021 for treatment of pain
• CPC Class Codes: A61N 1/36071 Pain

Abstract

The invention provides an implant, system and method for electrically stimulating a target tissue to either activate or block neural impulses. The implant provides a conductive pathway for a portion of electrical current flowing between surface electrodes positioned on the skin and transmits that current to the target tissue. The implant has a passive electrical conductor of sufficient length to extend from subcutaneous tissue located below a surface cathodic electrode to the target tissue. The conductor has a pick-up end which forms an electrical termination having a sufficient surface area to allow a sufficient portion of the electrical current to flow through the conductor, in preference to flowing through body tissue between the surface electrodes, such that the target tissue is stimulated to either activate or block neural impulses. The conductor also has a stimulating end which forms an electrical termination for delivering the current to the target body tissue.

Claims

1. An implant for electrically stimulating a target body tissue in a subject, the implant, once implanted, providing a conductive pathway for at least a portion of the electrical current flowing between surface cathodic and anodic electrodes positioned in spaced relationship on the subject'"'"'s skin and transmitting the portion of the electrical current to the target body tissue, the implant comprising:

a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between its ends, the pick-up end forming an electrical termination having a sufficient surface area to allow a portion of the electrical current to flow through the conductor, in preference to flowing through body tissue between the surface cathodic and anodic electrodes, such that the target body tissue is stimulated, and the stimulating end forming an electrical termination to deliver the portion of the electrical current to the target body tissue, the implant being configured to provide electrical conductivity between body tissue and the conductor to allow the portion of the electrical current to flow, wherein the implant is configured to pick up the portion of the electrical current via resistive coupling.

2. The implant according to claim 1, wherein the conductor is formed from at least one of a metal wire, carbon fibers, a conductive rubber or other conductive polymer, or a conductive salt solution in rubber.

3. The implant according to claim 1, wherein the electrical termination on at least one of the pick-up end and the stimulating end of the conductor includes an enlarged surface area in the form of a coil, a spiral, a cuff, a rod, or a plate or a sheet in the form of an oval or a polygon.

4. The implant according to claim 1, wherein at least one of the electrical terminations of the conductor is formed from at least one of an uninsulated end of the conductor, or from other conductive or capacitive materials.

5. The implant according to claim 1, further comprising a coating on one or both of the terminations, the coating being at least one of a conductive or capacitive coating, an oxide layer, an anti-inflammatory agent, an antibacterial agent, an antibiotic, or a tissue ingrowth promoter.

6. The implant of claim 1, wherein the implant is further configured to pick up the portion of the electrical current at least partially via capacitive coupling.

7. The implant according to claim 1, wherein the implant further comprises:

an electrical return conductor of sufficient length to extend, once implanted, from the target tissue to subcutaneous tissue located below the surface anodic electrode, the return conductor having a collecting end and a returning end and being insulated between the collecting end and the returning end, the collecting end forming an electrical termination having a sufficient surface area to allow a portion of the current delivered to the target body tissue to return through the return conductor in preference to returning through body tissue, and the returning end forming an electrical termination that returns the electrical current to the surface anodic electrode via the subcutaneous tissue and skin underlying the surface anodic electrode.

8. The implant according to claim 7, wherein one or both of the conductor and the return conductor is formed from at least one of a metal wire, carbon fibers, a conductive rubber or other conductive polymer, or a conductive salt solution in rubber.

9. The implant according to claim 7, wherein the electrical termination on at least one of the pick-up end and the stimulating end of the conductor and the return conductor includes an enlarged surface area in the form of a coil, a spiral, a cuff, a rod, or a plate or a sheet in the form of an oval or a polygon.

10. The implant according to claim 7, wherein at least one of the electrical terminations of the conductor or the return conductor is formed from at least one of an uninsulated end of the conductor or return conductor, or from other conductive or capacitive materials.

11. The implant according to claim 7, further comprising a coating on one or both of the terminations of the conductor or the return conductor, the coating being at least one of a conductive or capacitive coating, an oxide layer, an anti-inflammatory agent, an antibacterial agent, an antibiotic, or a tissue ingrowth promoter.

12. A system configured to electrically stimulate a target body tissue in a subject comprising:

a surface cathodic electrode and a surface anodic electrode configured to make direct electrical contact with the subject'"'"'s skin, and to transmit electrical current to the target body tissue;

a stimulator external to the subject'"'"'s body, electrically connected to the surface cathodic and the surface anodic electrodes, the stimulator supplying direct, pulsatile, or alternating current to the surface cathodic electrode and the surface anodic electrode; and

an implant configured to pick up at least a portion of the electrical current flowing between the surface cathodic electrode and surface anodic electrode and transmit the portion of the electrical current to the target body tissue, the implant comprising a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between its ends, the pick-up end forming an electrical termination having a sufficient surface area to allow a portion of the electrical current being applied to flow through the conductor, in preference to the electrical current flowing through body tissue between the surface cathodic electrode and the surface anodic electrode, such that the target body tissue is stimulated, and the stimulating end forming an electrical termination to deliver the portion of the electrical current to the target body tissue, wherein the implant is configured to pick up the portion of the electrical current via resistive coupling.

13. The system according to claim 12, wherein the conductor is formed from at least one of a metal wire, carbon fibers, a conductive rubber or other conductive polymer, or a conductive salt solution in rubber.

14. The system according to claim 12, wherein at least one of the termination on the pick-up end or the termination on the stimulating end is configured to include an enlarged surface area in the form of at least one of a coil, a spiral, a cuff, a rod, or a plate or a sheet in the form of an oval or a polygon.

15. The system according to claim 12, wherein the surface cathodic electrode and the surface anodic electrode include a conductive plate or a conductive sheet, a conductive gel electrode, a conductive rubber or polymer electrode that may be partially coated with an electrode paste or gel, or a moistened absorbent pad electrode.

16. The system according to claim 12, wherein at least one of the electrical terminations of the conductor can be formed from at least one of an uninsulated end of the conductor or from other conductive or capacitive materials.

17. The system according to claim 12, further comprising a coating on one of both of the electrical terminations of the conductor, the coating being at least one of a conductive or capacitive coating, an oxide layer, an anti-inflammatory agent, an antibacterial agent, an antibiotic, or a tissue ingrowth promoter.

18. The system according to claim 12, wherein the implant is one implant from a plurality of implants, each of the plurality of implants configured to electrically stimulate target body tissue independently or in unison, each implant from the plurality of implants being implanted entirely under the subject'"'"'s skin and being of a sufficient length to extend to a different target body tissue, and the surface cathodic electrode being one of a plurality of surface cathodic electrodes and at least the surface cathodic electrode and the surface anodic electrode configured to be positioned relative to the plurality of implants to stimulate the different target body tissues independently or in unison.

19. The system of claim 12, wherein the implant is further configured to pick up the portion of the electrical current at least partially via capacitive coupling.

20. The system according to claim 12, further comprising an electrical return conductor of sufficient length to extend, once implanted, from the target tissue to subcutaneous tissue located below the surface anodic electrode, the return conductor having a collecting end and a returning end and being insulated between the collecting end and the returning end, the collecting end forming an electrical termination having a sufficient surface area to allow a portion of the current delivered to the target body tissue to return through the return conductor in preference to returning through body tissue, and the returning end forming an electrical termination to return the electrical current to the surface anodic electrode via the subcutaneous tissue and skin underlying the surface anodic electrode.

21. The system according to claim 20, wherein at least one of the conductor and the return conductor is formed from at least one of a metal wire, carbon fibers, a conductive rubber or other conductive polymer, or a conductive salt solution in rubber.

22. The system according to claim 20, wherein at least one of the termination on the pick-up end or the termination on the stimulating end is configured to include an enlarged surface area in the form of at least one of a coil, a spiral, a cuff, a rod, or a plate or a sheet in the form of an oval or a polygon.

23. The system according to claim 20, wherein the surface cathodic electrode and the surface anodic electrode include a conductive plate or a conductive sheet, a conductive gel electrode, a conductive rubber or polymer electrode that may be partially coated with an electrode paste or gel, or a moistened absorbent pad electrode.

24. The system according to claim 20, wherein at least one of the electrical terminations of the return conductor are can be formed from at least one of an uninsulated end of the conductor or from other conductive or capacitive materials.

25. The system according to claim 20, further comprising a coating on one or both of the electrical terminations of the conductor or the return conductor, the coating being at least one of a conductive or capacitive coating, an oxide layer, an anti-inflammatory agent, an antibacterial agent, an antibiotic, or a tissue ingrowth promoter.

26. The system according to claim 20, wherein the implant is one implant from a plurality of implants, each of the plurality of implants configured to electrically stimulate target body tissue independently or in unison, each implant from the plurality of implants being implanted entirely under the subject'"'"'s skin and being of a sufficient length to extend to a different target body tissue, and the surface cathodic electrode being one of a plurality of surface cathodic electrodes and at least the surface cathodic electrode and the surface anodic electrode configured to be positioned relative to the plurality of implants to stimulate the different target body tissues independently or in unison.

27. A method for electrically stimulating a target body tissue in a subject comprising:

implanting an implant entirely under the subject'"'"'s skin, the implant being configured to act as a conductive pathway for at least a portion of an electrical current flowing between a surface cathodic electrode and a surface anodic electrode to be positioned in spaced relationship on the subject'"'"'s skin and to transmit the portion of the electrical current to the target body tissue,

the implant comprising a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between the pick-up end and the stimulating end, the pick-up end being positioned in subcutaneous tissue located below the surface cathodic electrode and forming an electrical termination having a sufficient surface area to allow a portion of the electrical current to flow through the conductor, in preference to flowing through body tissue between the surface cathodic electrode and the surface anodic electrode, such that the target body tissue is stimulated, and the stimulating end being positioned proximate to the target body tissue and forming an electrical termination to deliver the portion of electrical current to the target body tissue;

positioning the surface cathodic electrode and the surface anodic electrode in spaced relationship on the subject'"'"'s skin to make direct electrical contact with the subject'"'"'s skin, with the surface cathodic electrode positioned over the pick-up end of the electrical conductor so the portion of the current is transmitted through the conductor to the target body tissue, and so that the current flows through the target body tissue and returns to the anodic surface electrode through body tissues or through an implanted electrical return conductor extending between the target body tissue and subcutaneous tissue located below the surface anodic electrode; and

applying direct, pulsatile or alternating electrical current between the surface cathodic electrode and the surface anodic electrode to cause the portion of the electrical current to flow through the implant to stimulate the target body tissue, wherein the portion of the electrical current flows to the implant via resistive coupling.

28. The method according to claim 27, further comprising implanting the return conductor entirely under the subject'"'"'s skin, the return conductor being of sufficient length to extend, once implanted, from the target tissue to subcutaneous tissue located below the surface anodic electrode, the return conductor having a collecting end and a returning end and being insulated between the collecting end and the returning end, the collecting end forming an electrical termination having a sufficient surface area to allow a portion of the electrical current delivered to the target body tissue to return through the return conductor in preference to returning through body tissue, and the returning end forming an electrical termination to return the electrical current to the surface anodic electrode via the subcutaneous tissue and skin underlying the surface anodic electrode.

29. The method according to claim 27, wherein the body tissue includes at least one of a neural tissue in the peripheral nervous system or the central nervous system, a nerve, a muscle or an organ.

30. The method according to claim 29, wherein activation of the neural tissue or the nerve is conducted at a frequency in the range of between about 1 Hz and 100 Hz, alternatively in the range of between about 1 Hz and 50 Hz, or still alternatively, in the range of between about 1 Hz and 20 Hz, by applying pulsatile or alternating electrical current.

31. The method according to claim 27, wherein stimulation of the body tissue is conducted to treat a condition including at least one of a movement disorder, a muscular disorder, incontinence, urinary retention, pain, epilepsy, a cerebrovascular disorder, a sleep disorder, an autonomic disorder, a disorder of vision, a hearing or balance disorder, or a neuropsychiatric disorder, to promote bone growth or wound healing, or to promote tissue regeneration.

32. The method according to claim 27, wherein one or both of the conductor and the return conductor is formed from at least one of a metal wire, carbon fibers, a conductive rubber or other conductive polymer, or a conductive salt solution in rubber.

33. The method according to claim 27, wherein the terminations on one or both of the pick-up end or the stimulating end include an enlarged surface area in the form of a coil, a spiral, a cuff, a rod, or a plate or a sheet in the form of an oval or a polygon.

34. The method according to claim 27, wherein the surface cathodic electrode and the surface anodic electrode include a conductive plate or a conductive sheet, a conductive gel electrode, a conductive rubber or polymer electrode that may be partially covered with an electrode paste or gel, or a moistened absorbent pad electrode.

35. The method according to claim 27, wherein at least one of the electrical terminations of the conductor or the return conductor can be formed from at least one of an uninsulated end of the conductor or the return conductor or from other conductive or capacitive materials.

36. The method according to claim 27, further comprising a coating on one or both of the electrical terminations of the conductor or the return conductor, the coating being at least one of a conductive or capacitive coating, an oxide layer, an anti-inflammatory agent, an antibacterial agent, an antibiotic, or a tissue ingrowth promoter.

37. The method according to claim 27, the implant being one implant from a plurality of implants, the method further comprising implanting the plurality of implants to electrically stimulate more than one target body tissue independently or in unison, each implant from the plurality of implants being implanted entirely under the subject'"'"'s skin and being of a sufficient length to extend to a different target body tissue, and

positioning a plurality of surface cathodic electrodes and one or more surface anodic electrodes relative to the plurality of implants to stimulate the different target body tissues independently or in unison.

38. The method of claim 27, wherein the portion of the electrical current flows to the implant at least partially via capacitive coupling.

39. A method of treating a disorder in a subject comprising:

implanting an implant entirely under the subject'"'"'s skin, the implant configured to act as a conductive pathway for at least a portion of an electrical current flowing between a surface cathodic electrode and a surface anodic electrode to be positioned in spaced relationship on the subject'"'"'s skin and to transmit the portion of the electrical current to the target body tissue,

the implant comprising a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between the pick-up end and the stimulating end, the pick-up end being positioned in subcutaneous tissue located below the surface cathodic electrode and forming an electrical termination having a sufficient surface area to allow a portion of the electrical current to flow through the conductor, in preference to flowing through body tissue between the surface cathodic electrode and the surface anodic electrode, such that the target body tissue is stimulated, and the stimulating end being positioned proximate to the target body tissue and forming an electrical termination to deliver the portion of electrical current to the target body tissue;

positioning the surface cathodic electrode and the surface anodic electrode in spaced relationship on the subject'"'"'s skin to make direct electrical contact with the subject'"'"'s skin, with the surface cathodic electrode positioned over the pick-up end of the electrical conductor so the portion of the current is transmitted through the conductor to the target body tissue, and so that the current flows through the target body tissue and returns to the anodic surface electrode through body tissues or through an implanted electrical return conductor extending between the target body tissue and subcutaneous tissue located below the surface anodic electrode; and

applying electrical current between the surface cathodic electrode and the surface anodic electrode in a cyclical waveform at a frequency capable of blocking the target body tissue so as to treat the disorder, wherein the portion of the electrical current flows to the implant via resistive coupling.

40. The method according to claim 39, further comprising implanting the return conductor entirely under the subject'"'"'s skin, the return conductor being of sufficient length to extend, once implanted, from the target tissue to subcutaneous tissue located below the surface anodic electrode, the return conductor having a collecting end and a returning end and being insulated between the collecting end and the returning end, the collecting end forming an electrical termination having a sufficient surface area to allow a portion of the electrical current delivered to the target body tissue to return through the return conductor in preference to returning through body tissue, and the returning end forming an electrical termination to return the electrical current to the surface anodic electrode via the subcutaneous tissue and skin underlying the surface anodic electrode.

41. The method according to claim 39, wherein the disorder includes at least one of urinary retention, incontinence, pain, epilepsy, a cerebrovascular disorder, a sleep disorder, an autonomic disorder, a disorder of vision, a hearing or a balance disorder, a neuropsychiatric disorder or a movement disorder.

42. The method according to claim 39, wherein the body tissue includes a neural tissue in the peripheral nervous system or the central nervous system or a nerve.

43. The method according to claim 39, wherein the electrical current is in the form of a cyclical waveform applied at a frequency in the range of between about 100 Hz and 30,000 Hz.

44. The method according to claim 39, wherein the electrical current is in the form of a cyclical waveform applied at a frequency in the range of between about 100 Hz and 20,000 Hz, alternatively in the range of between about 100 Hz and 10,000 Hz, and still alternatively in the range of between about 200 Hz and 5,000 Hz.

45. The method according to claim 39, wherein one or both of the conductor and the return conductor is formed from at least one of a metal wire, carbon fibers, a conductive rubber or other conductive polymer, or a conductive salt solution in rubber.

46. The method according to claim 39, wherein the electrical terminations on one or both of the pick-up end or the stimulating end include an enlarged surface area in the form of a coil, a spiral, a cuff, a rod, or a plate or a sheet in the form of an oval or a polygon.

47. The method according to claim 39, wherein the surface cathodic electrode and the surface anodic electrode include a conductive plate or a conductive sheet, a conductive gel electrode, a conductive rubber or polymer electrode that may be partially covered with an electrode paste or gel, or a moistened absorbent pad electrode.

48. The method according to claim 39, wherein at least one of the electrical terminations of the conductor or the return conductor can be formed from at least one of an uninsulated end of the conductor or the return conductor or from other conductive or capacitive materials.

49. The method according to claim 39, further comprising a coating formed on at least one of the electrical terminations of the conductor or the return conductor, the coating being at least one of a conductive or capacitive coating, an oxide layer, an anti-inflammatory agent, an antibacterial agent, an antibiotic, or a tissue ingrowth promoter.

50. The method according to claim 39, the implant being one implant from a plurality of implants, the method further comprising implanting a plurality of implants to electrically block more than one target body tissue independently or in unison, each implant from the plurality of implants being implanted entirely under the subject'"'"'s skin and being of a sufficient length to extend to a different target body tissue, and

positioning a plurality of surface cathodic electrodes and one or more surface anodic electrodes relative to the plurality of implants to block the different target body tissues independently or in unison.

51. The method according to claim 39, the implant being one implant from a plurality of implants, the method further comprising implanting the plurality of implants to electrically stimulate an action potential in more than one target body tissue independently or in unison, each implant from the plurality of implants being implanted entirely under the subject'"'"'s skin and being of a sufficient length to extend to a different target body tissue, and

positioning a plurality of surface cathodic electrodes and one or more surface anodic electrodes relative to the plurality of implants to stimulate the different target body tissues independently or in unison.

52. The method of claim 39, wherein the portion of the electrical current flows to the implant at least partially via capacitive coupling.

53. An implant for electrically stimulating a target body tissue in a subject, the implant, once implanted, providing a conductive pathway for at least a portion of the electrical current flowing between surface cathodic and anodic electrodes positioned in spaced relationship on the subject'"'"'s skin and transmitting the portion of the electrical current to the target body tissue, the implant comprising:

a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between its ends, the pick-up end forming an electrical termination having a sufficient surface area to allow a portion of the electrical current to flow into and through the conductor via resistive coupling, in preference to flowing through body tissue between the surface cathodic and anodic electrodes, such that the target body tissue is stimulated, and the stimulating end forming an electrical termination to deliver the portion of the electrical current to the target body tissue, the implant being configured to provide electrical conductivity between body tissue and the conductor to allow the portion of the electrical current to flow.

54. The implant of claim 53, wherein the portion of the electrical current flows into and through the conductor at least partially via capacitive coupling.

55. A system configured to electrically stimulate a target body tissue in a subject comprising:

a surface cathodic electrode and a surface anodic electrode configured to make direct electrical contact with the subject'"'"'s skin, and to transmit electrical current to the target body tissue;

a stimulator external to the subject'"'"'s body, electrically connected to the surface cathodic and the surface anodic electrodes, the stimulator supplying direct, pulsatile, or alternating current to the surface cathodic electrode and the surface anodic electrode; and

an implant configured to pick up at least a portion of the electrical current flowing between the surface cathodic electrode and surface anodic electrode and transmit the portion of the electrical current to the target body tissue, the implant comprising a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between its ends, the pick-up end forming an electrical termination having a sufficient surface area to allow a portion of the electrical current being applied to flow into and through the conductor without magnetic inductive coupling, in preference to the electrical current flowing through body tissue between the surface cathodic electrode and the surface anodic electrode, such that the target body tissue is stimulated, and the stimulating end forming an electrical termination to deliver the portion of the electrical current to the target body tissue.

56. A method for electrically stimulating a target body tissue in a subject comprising:

implanting an implant entirely under the subject'"'"'s skin, the implant being configured to act as a conductive pathway for at least a portion of an electrical current flowing between a surface cathodic electrode and a surface anodic electrode to be positioned in spaced relationship on the subject'"'"'s skin and to transmit the portion of the electrical current to the target body tissue,

the implant comprising a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between the pick-up end and the stimulating end, the pick-up end being positioned in subcutaneous tissue located below the surface cathodic electrode and forming an electrical termination having a sufficient surface area to allow a portion of the electrical current to flow into and through the conductor without magnetic inductive coupling, in preference to flowing through body tissue between the surface cathodic electrode and the surface anodic electrode, such that the target body tissue is stimulated, and the stimulating end being positioned proximate to the target body tissue and forming an electrical termination to deliver the portion of electrical current to the target body tissue;

positioning the surface cathodic electrode and the surface anodic electrode in spaced relationship on the subject'"'"'s skin to make direct electrical contact with the subject'"'"'s skin, with the surface cathodic electrode positioned over the pick-up end of the electrical conductor so the portion of the current is transmitted through the conductor to the target body tissue, and so that the current flows through the target body tissue and returns to the anodic surface electrode through body tissues or through an implanted electrical return conductor extending between the target body tissue and subcutaneous tissue located below the surface anodic electrode; and

applying direct, pulsatile or alternating electrical current between the surface cathodic electrode and the surface anodic electrode to cause the portion of the electrical current to flow through the implant to stimulate the target body tissue.

57. A method of treating a disorder in a subject comprising:

implanting an implant entirely under the subject'"'"'s skin, the implant configured to act as a conductive pathway for at least a portion of an electrical current flowing between a surface cathodic electrode and a surface anodic electrode to be positioned in spaced relationship on the subject'"'"'s skin and to transmit the portion of the electrical current to the target body tissue,

the implant comprising a passive electrical conductor of sufficient length to extend, once implanted, from subcutaneous tissue located below the surface cathodic electrode to the target body tissue, the electrical conductor having a pick-up end and a stimulating end and being insulated between the pick-up end and the stimulating end, the pick-up end being positioned in subcutaneous tissue located below the surface cathodic electrode and forming an electrical termination having a sufficient surface area to allow a portion of the electrical current to flow into and through the conductor without magnetic inductive coupling, in preference to flowing through body tissue between the surface cathodic electrode and the surface anodic electrode, such that the target body tissue is stimulated, and the stimulating end being positioned proximate to the target body tissue and forming an electrical termination to deliver the portion of electrical current to the target body tissue;

positioning the surface cathodic electrode and the surface anodic electrode in spaced relationship on the subject'"'"'s skin to make direct electrical contact with the subject'"'"'s skin, with the surface cathodic electrode positioned over the pick-up end of the electrical conductor so the portion of the current is transmitted through the conductor to the target body tissue, and so that the current flows through the target body tissue and returns to the anodic surface electrode through body tissues or through an implanted electrical return conductor extending between the target body tissue and subcutaneous tissue located below the surface anodic electrode; and

applying electrical current between the surface cathodic electrode and the surface anodic electrode in a cyclical waveform at a frequency capable of blocking the target body tissue so as to treat the disorder.