WIRELESS ENERGY TRANSFER FOR IMPLANTABLE DEVICES

• US 20120032522A1
• Filed: 06/06/2011
• Published: 02/09/2012
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Schatz, David A., Kesler, Morris P., Hall, Katherine L., Ganem, Steven J.
• Granted Patent: US 9,577,436 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: A61M 2205/8243 by induction
• 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 60/191 mechanically acting upon the outside of the patient's native heart, e.g. compressive structures placed around the heart
• CPC Class Codes: A61M 60/289 Devices for mechanical circulatory actuation assisting the residual heart function by means mechanically acting upon the patient's native heart or blood vessel structure, e.g. direct cardiac compression [DCC] devices
• CPC Class Codes: A61M 60/875 specially adapted for optimising alignment of external and implantable coils
• CPC Class Codes: A61N 1/3975 Power supply A61N1/378 takes precedence
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: H01F 2003/005 Magnetic cores for receiving several windings with perpendicular axes, e.g. for antennae or inductive power transfer
• 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 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Described herein are improved configurations for a wireless power transfer. Described are methods and designs for implantable electronics and devices. Wireless energy transfer is utilized to eliminate cords and power cables puncturing the skin to power an implantable device. Repeater resonators are employed to improve the power transfer characteristics between the source and the device resonators.

Claims

1. A wireless energy transfer system for powering devices implanted in a patient comprising:

a high-Q source resonator having a first resonant frequency, the source resonator being external to the patient, coupled to a power source, and configured to generate oscillating magnetic fields at substantially the first resonant frequency,

a high-Q device resonator having a second resonant frequency, the device resonator coupled to an implantable device requiring a supply power, the device resonator being internal to the patient, and configured to capture the oscillating magnetic fields generated by the source resonator,

a repeater resonator;

wherein the repeater resonator is positioned to improve the energy transfer between the source resonator and the device resonator.

2. The wireless energy transfer system of claim 1, wherein the repeater resonator is external to the patient.

3. The wireless energy transfer system of claim 2, wherein the repeater resonator is integrated into a garment wearable by the patient.

4. The wireless energy transfer system of claim 1, wherein the repeater resonator is internal to the patient.

5. The wireless energy transfer system of claim 1, further comprising at least one additional repeater resonator positioned to improve the wireless energy transfer between the source resonator and the device resonator.

6. The wireless energy transfer system of claim 5, wherein the repeater resonators are positioned to provide substantially uniform energy transfer between the source resonator and the device resonator over a range of positions of the source resonator.

7. The wireless energy transfer system of claim 1, wherein the repeater resonator comprises at least one loop of Litz wire.

8. The wireless energy transfer system of claim 1, wherein the source resonator and the device resonator have a Q>

100.

9. The wireless energy transfer system of claim 1, wherein the repeater resonator is positioned to improve the coupling between the source and device by at least 10%.

10. A wireless energy transfer system for powering devices implanted in a patient comprising:

a high-Q source resonator having a first resonant frequency, the source resonator being external to the patient, coupled to a power source, and configured to generate oscillating magnetic fields at substantially the first resonant frequency,

a high-Q device resonator having a second resonant frequency, the device resonator coupled to an implantable device requiring a supply power, the device resonator being internal to the patient, and configured to capture the oscillating magnetic fields generated by the source resonator,

a temperature sensor, positioned to measure the temperature of the device resonator, and

a tunable component coupled to the device resonator,

wherein the tunable component is adjusted to change the first resonant frequency of the device resonator in response to the reading from the temperature sensor.

11. The wireless energy transfer system of claim 10, wherein the tunable component is adjusted to change the first resonant frequency to a lower frequency away from the second resonant frequency.

12. The wireless energy transfer system of claim 10, wherein the tunable component is adjusted to change the first resonant frequency to a higher frequency away from the second resonant frequency.

13. The wireless energy transfer system of claim 10, wherein the tunable component is adjusted maintain the temperature of the device resonator below 50 degrees Celsius.

14. The wireless energy transfer system of claim 10, wherein the tunable component is a capacitor.

15. The wireless energy transfer system of claim 10, wherein the tunable component is an inductor.

16. The wireless energy transfer system of claim 10, wherein the strength of the oscillating magnetic fields generated by the source resonator is adjusted to maintain a substantially uniform level of power captured by the device resonator.

17. The wireless energy transfer system of claim 16, wherein the strength of the oscillating magnetic fields generated by the source resonator is adjusted by changing the driving voltage of the source resonator.

18. The wireless energy transfer system of claim 16, wherein the strength of the oscillating magnetic fields generated by the source resonator is adjusted by changing the driving current of the source resonator.

19. The wireless energy transfer system of claim 10, wherein the source resonator and the device resonator have a Q>

100.