Implantable wireless power system

• US 8,901,775 B2
• Filed: 03/02/2011
• Issued: 12/02/2014
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: Corvion Incorporated
• Original Assignee: EverHeart Systems Inc.
• Inventors: Armstrong, Randolph K., Aber, Greg S.
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Kessie, Daniel
• Application Number:
  US13/038,671
• Publication Number:
  US 20120146575A1
• Time in Patent Office: 1,371 Days
• Field of Search: 307/104, 307/108
• US Class Current: 307/104
• CPC Class Codes: A61M 2205/8243 by induction
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/226 the blood flow through the rotating member having mainly radial components
• CPC Class Codes: A61M 60/232 Centrifugal pumps
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/824 Hydrodynamic or fluid film bearings
• CPC Class Codes: A61M 60/873 specially adapted for wireless or transcutaneous energy transfer [TET], e.g. inductive charging
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

A wireless power system capable of transmitting power through the skin without percutaneous wires over distances ranging from a few inches to several feet includes an external transmitting coil assembly and a receiving coil assembly. The transmitting coil assembly includes an excitation coil and transmitting resonant coil which are inductively coupled to each other. The receiving coil assembly includes a receiving resonant coil and a power pick-up coil which are also inductively coupled to each other. A high frequency AC power input, such as radio frequency (RF), supplied to the excitation coil inductively causes the transmitting resonant coil to resonate resulting in a local time varying magnetic field. The transmitting and receiving resonant coils are constructed as to have closely matched or identical resonant frequencies so that the magnetic field produced by the transmitting resonant coil is able to cause the receiving resonant coil to resonate strongly also, even when the distance between the two resonant coils greatly exceeds the largest dimension of either coil. The receiving resonant coil then creates its own local time varying magnetic field which inductively produces a voltage in a power pick-up coil to provide power to an active implantable medical device or implantable rechargeable battery.

Claims

1. An apparatus for use in wireless energy transfer to power a medical device, the apparatus comprising:

a transmitting assembly configured to transmit electromagnetic energy, the transmitting assembly comprising,

a transmitting resonant coil providing a first conductor; and

an excitation coil inductively coupled to said transmitting resonant coil;

a receiving assembly magnetic resonance coupled to the transmitting assembly, the receiving assembly comprising,

a receiving resonant coil sized to be implantable in a human body and providing a second conductor; and

a power pick-up coil inductively coupled to said receiving resonant coil;

wherein a first capacitor is electrically connected to said first conductor and a second capacitor is electrically connected to said second conductor; and

wherein said first conductor and/or second conductor has a thickness T, smaller than a width W of said first conductor and/or second conductor, such that every point within said first conductor and/or second conductor resides within a skin depth at a resonant frequency of said transmitting resonant coil and/or receiving resonant coil, wherein the skin depth is defined by

2. The apparatus of claim 1, wherein said first conductor and/or second conductor is a foil or a plating.

3. The apparatus of claim 1, wherein said first conductor and/or second conductor provides two conductive layers arranged on opposing faces of a coil structure formed from an electrically non-conductive material.

4. The apparatus of claim 1, wherein said first conductor and/or second conductor provides a continuous electrically conductive layer arranged around all surfaces of a coil structure formed from an electrically non-conductive material.

5. The apparatus of claim 1, wherein a length of said first conductor and/or second conductor is less than one tenth of a resonant frequency wavelength of said transmitting and/or receiving resonant coil.

6. The apparatus of claim 1, wherein an enclosed area of said transmitting resonant coil is at least twice an enclosed area of said receiving resonant coil.

7. The apparatus of claim 1, wherein said receiving assembly is secured in a hermetically-sealed biocompatible housing, and said receiving assembly is implantable into a human body.

8. The apparatus of claim 1, wherein said power pick-up coil is within an enclosed volume of said receiving resonant coil.

9. The apparatus of claim 1, wherein said first conductor and/or second conductor is insulated from previous or subsequent coil turns by one or more electrical insulating media having a dielectric dissipation factor of 0.01 or less.

10. The apparatus of claim 1, wherein a distance between said transmitting assembly and said receiving assembly is equal to or greater than five times a largest dimension of said receiving resonant coil.

11. The apparatus of claim 1, wherein said receiving assembly provides power to recharge an implantable battery, to operate an implantable medical device, or to simultaneously recharge an implantable battery and operate an implantable medical device.

12. The apparatus of claim 1 comprising one or more sympathetic resonant coils, wherein the sympathetic resonant coils extend a transmission range for wireless energy transfer.

13. The apparatus of claim 12, wherein one or more sympathetic resonant coils are over-coupled with said transmitting resonant coil.

14. The apparatus of claim 1, wherein a first electrical insulating medium between coil turns of the transmitting resonant coil and/or a second electrical insulating medium between coil turns of the receiving resonant coil provides a dielectric dissipation factor of 0.01 or less.

15. The apparatus of claim 1, wherein a first electrical insulating medium between coil turns of the transmitting resonant coil and/or a second electrical insulating medium between coil turns of the receiving resonant coil is solid with a polygonal cross section.

16. The apparatus of claim 1, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 100.

17. The apparatus of claim 1, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 300.

18. The apparatus of claim 1, wherein an electrical insulating medium between coil turns of the receiving resonant coil provides a dielectric dissipation factor of 0.01 or less;

wherein said second conductor is a foil or a plating;

wherein said second insulating medium is solid with a polygonal cross section; and

wherein said receiving resonant coil has a quality factor Q greater than 300.

19. The apparatus of claim 1, wherein said transmitting resonant coil has a diameter of 6 inches or greater.

20. The apparatus of claim 1, wherein said transmitting resonant coil has a quality factor Q greater than 600.

21. The apparatus of claim 1, wherein said first conductor has a width W of 1.0 inch or less.

22. An apparatus for use in wireless energy transfer to power a medical device, the apparatus comprising:

a transmitting assembly configured to transmit electromagnetic energy, the transmitting assembly comprising,

a transmitting resonant coil providing a first conductor and a first electrical insulating medium between coil turns of said first conductor; and

an excitation coil inductively coupled to said transmitting resonant coil; and

a receiving assembly magnetic resonance coupled to the transmitting assembly, the receiving assembly comprising,

a receiving resonant coil providing a second conductor and a second electrical insulating medium between coil turns of said second conductor; and

a power pick-up coil inductively coupled to said receiving resonant coil;

wherein a first capacitor is electrically connected to said first conductor and a second capacitor is electrically connected to said second conductor;

wherein said first and/or second insulating medium comprises one or more dielectric materials that is solid with a polygonal cross section, said first and/or second insulating medium providing a dielectric dissipation factor of 0.01 or less;

wherein said first and/or second conductor has a thickness T of less than 0.02 inches and a width W of 0.5 inch or less; and

wherein said transmitting and/or receiving resonant coil has a diameter of 3 inches or less.

23. The apparatus of claim 22, wherein said first and/or second conductor has an inter-turn spacing D greater than 0.003 inch.

24. The apparatus of claim 22, wherein each of said first and second capacitors has a temperature coefficient of less than 3000 ppm/degree C and a total capacitance at least one tenth of the capacitance provided by said first and/or second insulating medium.

25. The apparatus of claim 22, wherein the first capacitor is electrically connected to a start and an end of said coil turns of said first conductor, the second capacitor is electrically connected to a start and an end of said coil turns of the second conductor, and each of said first and second capacitors has a dielectric dissipation factor of 0.01 or less.

26. The apparatus of claim 22, wherein the thickness T and the width W are sized such that every point within said first conductor and/or second conductor resides within a skin depth at a resonant frequency of said transmitting resonant coil and/or receiving resonant coil, wherein the skin depth is defined by

27. The apparatus of claim 22, wherein the thickness T is smaller than the width W and wherein said first conductor and/or second conductor is a foil or a plating.

28. The apparatus of claim 22, wherein said power pick-up coil is within an enclosed volume of said receiving resonant coil.

29. The apparatus of claim 22, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 100.

30. The apparatus of claim 22, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 300.

31. The apparatus of claim 22, wherein the thickness T is smaller than the width W, such that every point within said second conductor resides within a skin depth at a resonant frequency of said receiving resonant coil, wherein the skin depth is defined by

32. The apparatus of claim 22, wherein said transmitting resonant coil has a diameter of 6 inches or greater.

33. The apparatus of claim 22, wherein said transmitting resonant coil has a quality factor Q greater than 600.

34. The apparatus of claim 22, wherein said first conductor has a width W of 1.0 inch or less.

35. An apparatus for use in wireless energy transfer to power a medical device, the apparatus comprising:

a transmitting assembly configured to transmit electromagnetic energy, the transmitting assembly comprising,

a transmitting resonant coil providing a first conductor and a first electrical insulating medium between coil turns of said first conductor; and

an excitation coil inductively coupled to said transmitting resonant coil; and

a receiving assembly magnetic resonance coupled to the transmitting assembly, the receiving assembly comprising,

a receiving resonant coil providing a second conductor and a second electrical insulating medium between coil turns of said second conductor;

a power pick-up coil inductively coupled to said receiving resonant coil;

a rectification circuit connected to said power pick-up coil;

DC filter components connected to said rectification circuit; and

a biocompatible housing which houses and hermetically seals the receiving resonant coil, the power pick-up coil, the rectification circuit, and the DC filter components from body fluids and tissues;

wherein a first capacitor is electrically connected to said first conductor and a second capacitor is electrically connected to said second conductor;

wherein said first and/or second insulating medium comprises one or more solid dielectric materials providing a dielectric dissipation factor of 0.01 or less;

wherein said first and/or second conductor has a thickness T of less than 0.02 inches and a width W of 0.5 inch or less;

wherein the thickness T is smaller than the width W; and

wherein said transmitting and/or receiving resonant coil has a diameter of 3 inches or less.

36. The apparatus of claim 35, wherein said power pick-up coil is implanted proximate to a skin surface, and said excitation coil is placed proximate to said receiving assembly to inductively transfer power to said power pick-up coil.

37. The apparatus of claim 35, wherein the thickness T and the width W are sized such that every point within said first conductor and/or second conductor resides within a skin depth at a resonant frequency of said transmitting resonant coil and/or receiving resonant coil, wherein the skin depth is defined by

38. The apparatus of claim 35, wherein said first conductor and/or second conductor is a foil or a plating.

39. The apparatus of claim 35, wherein said first and/or second insulating medium has a polygonal cross section.

40. The apparatus of claim 35, wherein said power pick-up coil is within an enclosed volume of said receiving resonant coil.

41. The apparatus of claim 35, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 100.

42. The apparatus of claim 35, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 300.

43. The apparatus of claim 35, wherein the thickness T is smaller than the width W, such that every point within said second conductor resides within a skin depth at a resonant frequency of said receiving resonant coil, wherein the skin depth is defined by

44. The apparatus of claim 35, wherein said transmitting resonant coil has a diameter of 6 inches or greater.

45. The apparatus of claim 35, wherein said transmitting resonant coil has a quality factor Q greater than 600.

46. The apparatus of claim 35, wherein said first conductor has a width W of 1.0 inch or less.

47. An apparatus for use in wireless energy transfer to power a medical device, the apparatus comprising:

a transmitting assembly configured to transmit electromagnetic energy, the transmitting assembly comprising,

a transmitting resonant coil providing a first conductor; and

an excitation coil inductively coupled to said transmitting resonant coil;

a receiving assembly sized to be implantable inside a human body, wherein the receiving assembly comprises a power pick-up coil hermetically sealed in a biocompatible housing; and

a receiving resonant coil magnetic resonance coupled to the transmitting assembly, wherein said receiving resonant coil comprises a second conductor that is inductively coupled to said power pick-up coil;

wherein a first capacitor is electrically connected to said first conductor and a second capacitor is electrically connected to said second conductor; and

wherein said first conductor and/or second conductor has a thickness T, smaller than a width W of said first conductor and/or second conductor, such that every point within said first conductor and/or second conductor resides within a skin depth at a resonant frequency of said transmitting resonant coil and/or receiving resonant coil, wherein the skin depth is defined by

48. The apparatus of claim 47, wherein said receiving assembly further comprises:

a rectification circuit connected to said power pick-up coil; and

DC filter components connected to said rectification circuit.

49. The apparatus of claim 47, wherein a first electrical insulating medium between coil turns of the transmitting resonant coil and/or a second electrical insulating medium between coil turns of the receiving resonant coil provides a dielectric dissipation factor of 0.01 or less.

50. The apparatus of claim 47, wherein a first electrical insulating medium between coil turns of the transmitting resonant coil and/or a second electrical insulating medium between coil turns of the receiving resonant coil is solid with a polygonal cross section.

51. The apparatus of claim 47, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 100.

52. The apparatus of claim 47, wherein said transmitting and/or receiving resonant coil has a quality factor Q greater than 300.

53. The apparatus of claim 47, wherein an electrical insulating medium between coil turns of the receiving resonant coil provides a dielectric dissipation factor of 0.01 or less;

wherein said second conductor is a foil or a plating; and

wherein said receiving resonant coil has a quality factor Q greater than 300.

54. The apparatus of claim 47, wherein said transmitting resonant coil has a diameter of 6 inches or greater.

55. The apparatus of claim 47, wherein said transmitting resonant coil has a quality factor Q greater than 600.

56. The apparatus of claim 47, wherein said first conductor has a width W of 1.0 inch or less.