IMPLANTABLE WIRELESS POWER SYSTEM

• US 20120146575A1
• Filed: 03/02/2011
• Published: 06/14/2012
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: Corvion Incorporated
• Original Assignee: Everheart Systems LLC
• Inventors: Armstrong, Randolph K., Aber, Greg S.
• Granted Patent: US 8,901,775 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• 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 comprises,

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 comprises,

a receiving resonant coil providing a second conductor; and

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

wherein said first conductor or second conductor has a thickness T that is less than or equal to two times a skin depth at the resonant frequency of said transmitting resonant coil or receiving resonant coil.

2. The apparatus of claim 1, wherein said first conductor or second conductor is a conductive foil or a conductive plating, and the conductor width W is larger than the thickness T.

3. The apparatus of claim 1, wherein said first conductor 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 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 thickness T of said first conductor or second conductor is less than 0.020 inch.

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

7. 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.

8. 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.

9. The apparatus of claim 8, wherein said receiving resonant coil is maintained in a stable temperature environment of 37+/−

5 degrees C.

10. The apparatus of claim 1, wherein said transmitting resonant coil is maintained in a stable temperature environment of 25+/−

5 degrees C.

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

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

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

14. 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.

15. 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.

16. The apparatus of claim 15, wherein one or more sympathetic resonant coils are over-coupled with said transmitting resonant coil.

17. 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 comprises,

a transmitting resonant coil providing a first conductor and a first 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 comprises,

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

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

wherein said first or second insulating medium comprises one or more dielectric materials that is solid with a polygonal cross section.

18. The apparatus of claim 17, wherein said dielectric materials have a dielectric dissipation factor of 0.01 or less.

19. The apparatus of claim 17, wherein said first or second conductor has an inter-turn spacing D greater than 0.003 inch.

20. The apparatus of claim 17, wherein one or more external capacitors are connected to a start and an end of said first conductor or second conductor, and said external capacitors have a temperature coefficient of less than 3000 ppm/degree C and a total capacitance at least one tenth of the capacitance provided by said insulating media.

21. The apparatus of claim 17, wherein one or more external capacitors are connected to a start and an end of said first conductor or second conductor, and said one or more external capacitors have a dielectric dissipation factor of 0.01 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 comprises,

a transmitting resonant coil providing a 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 comprises,

a receiving resonant coil providing a 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 all components from body fluids and tissues.

23. The apparatus of claim 22, wherein said receiving assembly is less than 1 inch thick.

24. The apparatus of claim 22, wherein a largest dimension of said receiving resonant coil is equal to or less than 3 inches and has a quality factor Q greater than 300.

25. The apparatus of claim 22, 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.

26. 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 comprises,

a transmitting resonant coil providing a first conductor; and

an excitation coil inductively coupled to said transmitting resonant coil;

a receiving assembly implanted 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.

27. The apparatus of claim 26, wherein said first conductor or second conductor has a thickness T that is less than or equal to two times a skin depth at the resonant frequency of said transmitting resonant coil or receiving resonant coil.

28. The apparatus of claim 26, 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.