Self-resonant inductor wound portion of an implantable lead for enhanced MRI compatibility of active implantable medical devices

• US 9,295,828 B2
• Filed: 11/18/2012
• Issued: 03/29/2016
• Est. Priority Date: 04/13/2001
• Status: Active Grant

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Halperin, Henry R., Stevenson, Robert A., Kondabatni, Kishore Kumar, Frysz, Christine A.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): D ABREU, MICHAEL JOSEPH
• Application Number:
  US13/680,083
• Publication Number:
  US 20130073021A1
• Time in Patent Office: 1,227 Days
• Field of Search: 607/116
• US Class Current: 1/1
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2090/374 NMR or MRI
• 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 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: G01R 33/3685 Means for reducing sheath currents, e.g. RF traps, baluns

Abstract

An implantable lead includes a lead conductor having a length extending from a proximal end to a distal end. A self-resonant inductor is connected in series along a portion of the length of the lead conductor. The self-resonant inductor includes a single length of conductive material including a dielectric coating substantially surrounding the single length of conductive material. The self-resonant inductor includes a first coiled or spiral conductor disposed along an inductor section spanning in a first direction from a first location to a second location. A second coiled or spiral conductor is disposed along the inductor section spanning in a second direction from the second location to the first location, where the second direction is opposite the first direction. A third coiled or spiral conductor is disposed along the inductor section spanning in the first direction from the first location to the second location.

Claims

1. An implantable lead, comprising:

a) at least one lead conductor extending from a proximal conductor end to a distal conductor portion having a distal conductor end, wherein the proximal conductor end is configured to be removably connectable or non-removably connected to electronic circuits of a medical device;

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end; and

c) a self-resonant inductor physically and electrically in series at or proximally adjacent to the at least one electrode, wherein the self-resonant inductor is of a continuous length of the at least one lead conductor and comprises;

i) a first insulated coiled portion of the continuous length of the lead conductor extending along a longitudinal axis in a distal direction from a first coiled portion proximal end to a first coiled portion distal end;

ii) a second insulated coiled portion of the continuous length of the lead conductor extending along the longitudinal axis in a proximal direction from a second coil portion distal end adjacent to the first coiled portion distal end to a second coiled portion proximal end; and

iii) a third insulated coiled portion of the continuous length of the lead conductor extending along the longitudinal axis in a distal direction from a third coiled portion proximal end adjacent to the second coiled portion proximal end to a third coiled portion distal end;

d) wherein the self-resonant inductor comprises parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of immediately adjacent ones of the first, second and third coiled portions of the continuous length of the lead conductor, and

ii) the immediately adjacent first and second coiled portions and the immediately adjacent second and third coiled portions aligned substantially perpendicular to the longitudinal axis, and

iii) the immediately adjacent first and second coiled portions and the immediately adjacent second and third coiled portions at an angle other than substantially perpendicular to the longitudinal axis,

e) wherein the self-resonant inductor is resonant at a first center frequency or across a range of frequencies about the first center frequency.

2. The lead of claim 1, wherein the self-resonant inductor is disposed inside a shield.

3. The lead of claim 2, wherein the self-resonant inductor comprises a parasitic capacitance between any or all of the first, second or third coiled conductors and the shield.

4. The lead of claim 3, wherein the self-resonant inductor comprises an equivalent circuit comprising an inductance in parallel with a capacitance.

5. The lead of claim 2, wherein the self-resonant inductor comprises an overall circuit Q within the shield and wherein the resultant 3-dB bandwidth is at least 128 kHz, so that the self-resonant inductor attenuates an RF current flow substantially about the first resonant center frequency that is at or near an MRI RF pulsed frequency.

6. The lead of claim 5, wherein the shield comprises a conductive electromagnetic shield.

7. The lead of claim 2, wherein the self-resonant inductor comprises a second resonant center frequency when removed from the shield and the first resonant center frequency within the shield, and wherein at least one of the inductance and the capacitance is adjusted to account for a shift between the first and second resonant center frequencies.

8. The lead of claim 1, wherein the first center frequency comprises an MRI RF pulsed frequency.

9. The lead of claim 8, wherein the self-resonant inductor has an inductance with an associated resistance and a parasitic capacitance with an associated resistance which inductance and parasitic capacitance and their respective resistances together determine a circuit Q having a resultant 3-dB bandwidth that is at least 128 kHz.

10. The lead of claim 9, wherein the circuit Q results in a 3-dB bandwidth that is on the order of megahertz.

11. The lead of claim 9, wherein the self-resonant inductor provides less than or equal to 3-dB of attenuation for a biological frequency range of 0-1 kHz.

12. The lead of claim 11, wherein the self-resonant inductor provides greater than or equal to 15-dB of attenuation at or near the MRI RF pulsed frequency.

13. The lead of claim 1, wherein the lead conductor is of a conductive material comprising an inner conductive core substantially surrounded by an outer conductive layer.

14. The lead of claim 13, wherein the outer conductive layer is biocompatible.

15. The lead of claim 13, wherein the outer conductive layer is selected from the group consisting of MP35N, nitinol, tungsten, tantalum, niobium, Co—

Cr—

Mo alloys, stainless steel alloys, stainless steel alloys with Mo, Ni, Cr combinations, carbon steels, and any combination thereof.

16. The lead of claim 13, wherein the inner conductive core is selected from the group consisting of silver, copper, platinum, platinum, platinum-iridium, platinum-tungsten, platinum alloys, tantalum, gold, palladium, nitinol, titanium, and titanium alloys.

17. The lead of claim 1, wherein the first, second and third coiled conductors are insulated with a dielectric coating selected from the group consisting of a thermoset, a thermoplastic coating, and a flexible coating.

18. The lead of claim 17, wherein the dielectric coating comprises a resin or modifier selected from the group consisting of pigments, plasticizers, filler particulates, flakes, spheres, nanoparticles, short fibers, long fibers, submicron fibers, isotropically dispersed submicron fibers, anistropically dispersed submicron fibers, laminate configurations, and any combination thereof.

19. The lead of claim 17, wherein the dielectric coating is selected from the group consisting of adhesives, elastomers, epoxies, fluoropolymers, copolymer blends, amorphous copolymer blends, semi-amorphous copolymer blends, copolymer blends with limited crosslinking, and any combination thereof.

20. The lead of claim 17, wherein the dielectric coating is selected from the group consisting of acrylonitrile butadiene styrene (ABS), acrylics, poly(methyl methacrylate) or PMMA, celluloids, acetates, cellulose acetate, ethylene-vinyl acetate, copolymers, cyclic olefin copolymer, polyethylene, poly(vinyl chloride), polystyrene, acetals, urethanes, carbothane, estane, pellethane, TECOFLEX®

, TECOTHANE®

, TEXIN®

, nylons, Aesno, Besno, Nylon 6, Nylon 6,6, Nylon 12, VESTAMID®

, polyether, polyester, polypropylene, polytetrafluoroethylene (PTFE), FEP, PFA, CTFE, ECTFE, PEEK, ETFE, PET, PBT, polyvinylidine fluoride (PVDF), ETTFE, THV, polycarbonate, polyetherimide, polysulfone, parylene, polyethylene, polypropylene, polyether block amides (PEBAX), acid copolymers, and any combination thereof.

21. The lead of claim 1, wherein the first coiled conductor is disposed radially inside the second coiled conductor, and wherein the second coiled conductor is disposed radially inside the third coiled conductor.

22. The lead of claim 1, wherein the lead conductor is of a conductive material selected from the group consisting of a cored tube, a clad tube, a plated tube, an electroplated tube, an anodized tube, and a filled tube.

23. The implantable lead of claim 1, wherein the self-resonant inductor is supported on a mandrel.

24. An elongate electrical medical lead, comprising:

a) at least one conductor with opposing proximal and distal conductor portions, wherein the proximal conductor portion is configured to be removably connectable or non-removably connected to electronic circuits of a medical device; and

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end,

c) wherein a continuous length of the at least one conductor comprises a first conductor section that extends in a first lengthwise direction along a longitudinal axis for a first physical length, then turns to define at least one reverse conductor section that extends in a substantially opposing lengthwise direction along the longitudinal axis for a second physical length, and then turns again to define a third conductor section that extends in the first lengthwise direction along the longitudinal axis for a third physical length,

d) wherein at least the first and reverse conductor sections or the reverse and third conductor sections are coiled conductor sections and have a parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of the immediately adjacent first and reverse coiled sections or the immediately adjacent reverse and third coiled sections of the continuous length of the lead conductor, and

ii) at least one of the immediately adjacent first and reverse coiled sections and the immediately adjacent reverse and third coiled sections, as the case may be, aligned substantially perpendicular to the longitudinal axis, and

iii) at least one of the immediately adjacent first and reverse coiled sections and the immediately adjacent reverse and third coiled sections, as the case may be, at an angle other than substantially perpendicular to the longitudinal axis;

e) wherein the at least first and reverse coiled conductor sections and the reverse and third coiled conductor sections, as the case may be, have an inductance with an associated resistance and the parasitic capacitance with an associated resistance which inductance and parasitic capacitance and their respective resistances together determine a circuit Q having a resultant 3-dB bandwidth that is at least 128 kHz.

25. The medical device of claim 24, wherein the at least one conductor comprising the first, reverse, and third conductor sections is disposed inside a shield.

26. The medical device of claim 25, wherein the at least one conductor comprises a parasitic capacitance between any of the first, reverse, and third conductor sections and the shield.

27. The medical device of claim 26, wherein the at least one conductor comprises an equivalent circuit comprising an inductance in parallel with a capacitance.

28. The medical device of claim 27, wherein the at least one conductor comprises an overall circuit Q within the shield and wherein the resultant 3-dB bandwidth is at least 128 kHz, so that the at least one conductor attenuates an RF current flow substantially about an MRI RF pulsed frequency.

29. The medical device of claim 25, wherein the shield comprises a conductive electromagnetic shield.

30. The medical device of claim 25, wherein the at least one conductor comprises a first resonant center frequency when removed from the shield and a second resonant center frequency within the shield, and wherein at least one of the inductance and the capacitance is adjusted to account for a shift between the first and second resonant center frequencies.

31. The medical device of claim 24, wherein the first, reverse, and third conductor sections comprise a continuous single length of conductive material.

32. The medical device of claim 31, wherein the continuous single length of conductive material is selected from the group consisting of a cored tube, a clad tube, a plated tube, an electroplated tube, an anodized tube, and a filled tube.

33. The medical device of claim 31, wherein the single length of conductive material comprises an inner conductive core substantially surrounded by an outer conductive layer, and wherein the outer conductive layer is biocompatible.

34. The medical device of claim 33, wherein the outer conductive layer is selected from the group consisting of MP35N, nitinol, tungsten, tantalum, niobium, Co—

Cr—

Mo alloys, stainless steel alloys, stainless steel alloys with Mo, Ni, Cr combinations, carbon steels, and any combination thereof.

35. The medical device of claim 33, wherein the inner conductive core is selected from the group consisting of silver, copper, platinum, platinum, platinum-iridium, platinum-tungsten, platinum alloys, tantalum, gold, palladium, nitinol, titanium, and titanium alloys.

36. The medical device of claim 24, wherein the first, reverse, and third conductor sections are insulated with a dielectric coating selected from the group consisting of a thermoset coating, a thermoplastic coating, and a flexible coating.

37. The medical device of claim 36, wherein the thermoset dielectric coating is selected from the group consisting of a resin or modifier comprising pigments, plasticizers, filler particulates, flakes, spheres, nanoparticles, short fibers, long fibers, submicron fibers, isotropically dispersed submicron fibers, anistropically dispersed submicron fibers, laminate configurations, and any combination thereof.

38. The medical device of claim 36, wherein the dielectric coating is selected from the group consisting of adhesives, elastomers, epoxies, fluoropolymers, copolymer blends, amorphous copolymer blends, semi-amorphous copolymer blends, copolymer blends with limited crosslinking, and any combination thereof.

39. The medical device of claim 36, wherein the dielectric coating is selected from the group consisting of acrylonitrile butadiene styrene (ABS), acrylics, poly(methyl methacrylate) or PMMA, celluloids, acetates, cellulose acetate, ethylene-vinyl acetate, copolymers, cyclic olefin copolymer, polyethylene, polyvinyl chloride), polystyrene, acetals, urethanes, carbothane, estane, pellethane, TECOFLEX®

, TECOTHANE®

, TEXIN®

, nylons, Aesno, Besno, Nylon 6, Nylon 6,6, Nylon 12, VESTAMID®

, polyether, polyester, polypropylene, polytetrafluoroethylene (PTFE), FEP, PFA, CTFE, ECTFE, PEEK, ETFE, PET, PBT, polyvinylidine fluoride (PVDF), ETTFE, THV, polycarbonate, polyetherimide, polysulfone, parylene, polyethylene, polypropylene, polyether block amides (PEBAX), acid copolymers, and any combination thereof.

40. The medical device of claim 24, wherein at least one of the first, reverse, and third conductor sections extends under, over or through a neighboring conductor section.

41. The medical device of claim 24, wherein at least one of the first, reverse, and third conductor sections resides proximate to and outside of a coiled portion of another conductor section.

42. The implantable lead of claim 24, wherein the first, reverse, and third conductor sections are supported on a mandrel.

43. An implantable lead, comprising:

a) at least one lead conductor extending from a proximal conductor end to a distal conductor portion having a distal conductor end, wherein the proximal conductor end is configured to be removably connectable or non-removably connected to electronic circuits of a medical device;

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end; and

c) a self-resonant inductor physically and electrically in series at or proximally adjacent to the at least one electrode, wherein the self-resonant inductor is of a continuous length of the at least one lead conductor and comprises;

i) a first insulated coiled layer of the continuous length of the lead conductor extending along a longitudinal axis in a distal direction from a first coiled layer proximal end to a first coiled layer distal end;

ii) a second insulated coiled layer of the continuous length of the lead conductor extending along the longitudinal axis in a proximal direction from a second coiled layer distal end adjacent to the first coiled layer distal end to a second coiled layer proximal end; and

iii) a third insulated coiled layer of the continuous length of the lead conductor extending along the longitudinal axis in a distal direction from a third coiled layer proximal end adjacent to the second coiled layer proximal end to a third coiled layer distal end;

d) wherein the self-resonant inductor comprises parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of immediately adjacent ones of the first, second and third coiled layers of the continuous length of the lead conductor, and

ii) the immediately adjacent first and second coiled layers and the immediately adjacent second and third coiled layers aligned substantially perpendicular to the longitudinal axis, and

iii) the immediately adjacent first and second coiled layers and the immediately adjacent second and third coiled layers at an angle other than substantially perpendicular to the longitudinal axis, and

e) wherein the self-resonant inductor is resonant at a center frequency or across a range of frequencies about the center frequency,

f) wherein the center frequency is at or near an MRI RF pulsed frequency, and

g) wherein a resultant 3-dB bandwidth of the self-resonant inductor is at least 128 kHz.

44. The lead of claim 43, wherein the self-resonant inductor is disposed inside a shield.

45. The lead of claim 44, wherein the shield comprises a conductive electromagnetic shield.

46. The lead of claim 43, wherein the first coiled conductor layer is electrically connected to the second coiled conductor layer, and wherein the second coiled conductor layer is electrically connected to the third coiled conductor layer.

47. The lead of claim 43, wherein the first coiled conductor layer is disposed radially inside the second coiled conductor layer, and wherein the second coiled conductor layer is disposed radially inside the third coiled conductor layer.

48. The lead of claim 43, wherein a dielectric coating surrounds at least a portion of the first, second and third coiled conductor layers.

49. The lead of claim 43, wherein the first, second and third coiled conductor layers comprise a continuous single length of conductive material.

50. The lead of claim 43, wherein the self-resonant inductor provides less than or equal to 3-dB of attenuation for a biological frequency range of 0-1 kHz, and wherein the self-resonant inductor provides greater than or equal to 15-dB of attenuation at or near the MRI RF pulsed frequency.

51. The implantable lead of claim 43 wherein the second coiled conductor proximal end is adjacent to the first coiled conductor proximal end and wherein the third coiled conductor distal end is adjacent to the second coiled conductor distal end.

52. The implantable lead of claim 43, wherein the self-resonant inductor is supported on a mandrel.

53. An implantable lead, comprising:

a) at least one lead conductor extending from a proximal conductor end to a distal conductor portion having a distal conductor end, wherein the proximal conductor end is configured to be removably connectable or non-removably connected to electronic circuits of a medical device;

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end; and

c) a self-resonant inductor in series at or proximally adjacent to the at least one electrode, wherein the self-resonant inductor is of a continuous length of the at least one lead conductor and comprises;

i) two or more even number of insulated coiled layers of the continuous length of the lead conductor extending proximally and distally from a first location to a second location along a longitudinal axis; and

ii) a return conductor electrically and physically connected to the electrode;

d) wherein the self-resonant inductor comprises parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of two immediately adjacent coiled layers of the two or more even number of coiled layers of the continuous length of the lead conductor, and

ii) the two immediately adjacent coiled layers aligned substantially perpendicular to the longitudinal axis, and

iii) the two immediately adjacent coiled layers at an angle other than substantially perpendicular to the longitudinal axis,

e) wherein the self-resonant inductor is resonant at or near an MRI RF pulsed frequency, and

f) wherein the self-resonant inductor has an inductance with an associated resistance and the parasitic capacitance with an associated resistance which inductance and parasitic capacitance and their respective resistances together provide a circuit Q having a resultant 3-dB bandwidth that is at least 128 kHz.

54. The lead of claim 53, wherein the circuit Q results in a 3-dB bandwidth that is on the order of megahertz.

55. The lead of claim 53, wherein the self-resonant inductor provides less than or equal to 3-dB of attenuation for a biological frequency range of 0-1 kHz.

56. The lead of claim 53, wherein the self-resonant inductor provides greater than or equal to 15-dB of attenuation at or near the MRI RF pulsed frequency.

57. The lead of claim 53, wherein the self-resonant inductor is disposed inside an electromagnetic shield, wherein the self-resonant inductor comprises a parasitic capacitance between its adjacent turns and between any of the two or more even number of layers of the coiled conductors and the shield, and wherein the self-resonant inductor comprises an equivalent circuit including an inductance in parallel with a capacitance along with their associated resistances, and wherein the self-resonant inductor comprises a first resonant center frequency when removed from the shield and a second resonant center frequency within the shield, wherein at least one of the inductance and the capacitance is adjusted to account for a shift between the first and second resonant center frequencies, and wherein the self-resonant inductor attenuates the MRI RF pulsed frequency substantially about the second resonant center frequency.

58. The implantable lead of claim 53, wherein the self-resonant inductor is supported on a mandrel.

59. An implantable lead, comprising:

a) a lead conductor having a length extending from a proximal conductor end to a distal conductor portion having distal conductor end; and

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end; and

c) a self-resonant inductor physically and electrically in series with the electrode, the self-resonant inductor comprising a dielectric coating substantially surrounding a continuous length of the at least one lead conductor, wherein the self-resonant inductor comprises

three or more odd number of insulated coiled layers of the continuous length of the lead conductor extending either proximally or distally along a longitudinal axis,

d) wherein the self-resonant inductor comprises a parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of two immediately adjacent coiled layers of the three or more odd number of coiled layers of the continuous length of the lead conductor, and

ii) the two immediately adjacent coiled layers aligned substantially perpendicular to the longitudinal axis, and

iii) the two immediately adjacent coiled layers at an angle other than substantially perpendicular to the longitudinal axis, and

d) wherein the self-resonant inductor has an inductance with an associated resistance and the parasitic capacitance with an associated resistance which inductance and parasitic capacitance and their respective resistances together provide a circuit Q having a resultant 3-dB bandwidth that is at least 128 kHz.

60. The implantable lead of claim 59, wherein the self-resonant inductor is supported on a mandrel.

61. The lead of claim 59, wherein the circuit Q results in a 3-db bandwidth that is on the order of megahertz.

62. The lead of claim 59, wherein the self-resonant inductor provides less than or equal to 3-dB of attenuation for a biological frequency range of 0-1 kHz.

63. The lead of claim 59, wherein the self-resonant inductor provides greater than or equal to 15-dB of attenuation at or near the MRI RF pulsed frequency.

64. The lead of claim 59, wherein the self-resonant inductor is disposed inside an electromagnetic shield, wherein the self-resonant inductor comprises a parasitic capacitance between its adjacent turns and between any of the three or more odd number of layers of coiled conductors and the shield, and wherein an equivalent circuit of the self-resonant inductor comprises an inductance in parallel with a capacitance along with their associated resistances, and wherein the self-resonant inductor comprises a first resonant center frequency when removed from the shield and a second resonant center frequency within the shield, wherein at least one of the inductance and the capacitance is adjusted to account for a shift between the first and second resonant center frequencies, and wherein the self-resonant inductor attenuates the MRI RF pulsed frequency substantially about the second resonant center frequency.

65. An implantable lead, comprising:

a) at least one lead conductor extending from a proximal conductor end to a distal conductor portion having a distal conductor end, wherein the proximal conductor end is configured to be removably connectable or non-removably connected to electronic circuits of an active implantable medical device;

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end; and

c) a self-resonant inductor physically and electrically in series at or proximally adjacent to the at least one electrode, wherein the self-resonant inductor is of a continuous length of the at least one lead conductor and comprises at least two insulated coiled conductors, and wherein;

i) a first one of the at least two insulated coiled portions of the continuous length of the lead conductor extends along a longitudinal axis in a distal direction from a first coiled portion proximal end to a first coiled portion distal end;

ii) a return conductor extends in a proximal direction from a return conductor distal end connected to the first coiled portion distal end to a return conductor proximal end; and

iii) a second one of the at least two insulated coiled portions of the continuous length of the lead conductor extends along the longitudinal axis in a distal direction from a second coiled portion proximal end adjacent to the return conductor proximal end to a second coiled portion distal end;

d) wherein the self-resonant inductor comprises parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of the immediately adjacent first and second coiled portions of the continuous length of the lead conductor, and

ii) the immediately adjacent first and second coiled portions aligned substantially perpendicular to the longitudinal axis, and

iii) the immediately adjacent first and second coiled portions at an angle other than substantially perpendicular to the longitudinal axis,

e) wherein the self-resonant inductor is resonant at a first center frequency or across a range of frequencies about the first center frequency.

66. The implantable lead of claim 65, wherein the return conductor resides inside the at least two insulated coiled conductors.

67. The implantable lead of claim 65, wherein the return conductor resides between the first and second insulated coiled conductors.

68. The implantable lead of claim 65, wherein the self-resonant inductor is supported on a mandrel.

69. An implantable lead, comprising:

a) at least one lead conductor extending from a proximal conductor end to a distal conductor portion having a distal conductor end, wherein the proximal conductor end is configured to be removably connectable or non-removably connected to electronic circuits of an active implantable medical device;

b) at least one electrode contactable with biological cells, wherein the electrode is electrically and physically connected to the distal conductor portion or the distal conductor end; and

c) a self-resonant inductor physically and electrically in series at or proximally adjacent to the at least one electrode, wherein the self-resonant inductor comprises at least two insulated coiled portions of a continuous length of the lead conductor, and wherein;

i) a first one of the at least two insulated coiled portions of the continuous length of the lead conductor extends along a longitudinal axis in a distal direction from a first coiled portion proximal end to a first coiled conductor distal end; and

ii) a second one of the at least two insulated coiled portions of the continuous length of the lead conductor extends in a proximal direction from a second coil portion distal end adjacent to the first coiled portion distal end to a second coiled portion proximal end;

d) wherein the self-resonant inductor comprises a total parasitic capacitance between;

i) axially extending and immediately adjacent surfaces of the immediately adjacent first and second coiled portions of the continuous length of the lead conductor, and

ii) the immediately adjacent first and second coiled portions aligned substantially perpendicular to the longitudinal axis, and

iii) the immediately adjacent first and second portions at an angle other than substantially perpendicular to the longitudinal axis,

e) wherein the self-resonant inductor is resonant at a first center frequency or across a range of frequencies about the first center frequency.

70. The implantable lead of claim 69, wherein the self-resonant inductor is supported on a mandrel.