FAR FIELD RADIATIVE POWERING OF IMPLANTABLE MEDICAL THERAPY DELIVERY DEVICES

• US 20130018438A1
• Filed: 03/29/2012
• Published: 01/17/2013
• Est. Priority Date: 07/14/2011
• Status: Active Grant

• Current Assignee: LivaNova USA, Inc. (LivaNova Plc)
• Original Assignee: Cyberonics, Inc
• Inventors: CHOW, Eric Y.
• Granted Patent: US 9,492,678 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/3782 producing a voltage above the power source level
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals

Abstract

A particular implantable device may include an antenna configured to receive a far field radiative signal. The implantable device may also include a voltage rectifier configured to rectify the far field radiative signal received by the antenna to provide a rectified voltage signal. The implantable device may further include a charge storage element operative to receive the rectified voltage signal and to store charge responsive to the rectified voltage signal. The implantable device may also include a therapy delivery unit powered by the charge storage element. The therapy delivery unit is operative to deliver a therapy to a patient.

Claims

1. An implantable medical device comprising:

an antenna configured to receive a far field radiative signal;

a voltage rectifier configured to rectify the far field radiative signal received by the antenna to provide a rectified voltage signal;

a charge storage element operative to receive the rectified voltage signal and to store charge responsive to the rectified voltage signal; and

a therapy delivery unit powered by the charge storage element, the therapy delivery unit operative to deliver a therapy to a patient.

2. The implantable medical device of claim 1, wherein the charge storage element is one of a capacitor, a capacitor array, a rechargeable battery, and a thin film battery.

3. The implantable medical device of claim 1, further comprising a control unit powered by the charge storage element, the control unit operative to control delivery of the therapy by the therapy delivery unit.

4. The implantable medical device of claim 1, wherein the voltage rectifier comprises a voltage multiplier.

5. The implantable medical device of claim 4, further comprising a DC-to-DC converter coupled to the voltage multiplier, wherein the DC-to-DC converter is configured to receive output of the voltage rectifier.

6. The implantable medical device of claim 1, wherein the voltage rectifier comprises Schottky diodes.

7. The implantable medical device of claim 6, wherein the Schottky diodes are complementary metal-oxide-semiconductor (CMOS) devices, and wherein each of the Schottky diodes has a forward bias voltage of 0.15 volts or less.

8. The implantable medical device of claim 1, further comprising a threshold detector coupled to the charge storage element, wherein the threshold detector is configured to determine when the charge stored at the charge storage element satisfies a charge threshold.

9. The implantable medical device of claim 1, wherein the far field radiative signal has a frequency in a frequency band centered at one of approximately 433 MHz, approximately 900 MHz, approximately 2.4 GHz, and approximately 5.8 GHz.

10. The implantable medical device of claim 1, wherein the far field radiative signal is transmitted over a distance of at least twice a wavelength of the far field radiative signal.

11. The implantable medical device of claim 1, wherein the far field radiative signal is transmitted over a distance of 0.1 meters or more.

12. The implantable medical device of claim 1, wherein the far field radiative signal has a free-space path loss that is proportional to a free-space path distance squared.

13. The implantable medical device of claim 1, wherein the far field radiative signal is a pulsed signal.

14. The implantable medical device of claim 13, wherein the pulsed signal has a duty cycle of 10% or less.

15. The implantable medical device of claim 1, wherein a quantity of the charge stored by the charge storage element enables the therapy delivery unit to deliver the therapy to the patient during a period of 24 hours or less.

16. The implantable medical device of claim 1, wherein a quantity of the charge stored by the charge storage element enables the therapy delivery unit to deliver only a single treatment of the therapy to the patient.

17. A method comprising:

receiving a far field radiative signal at an antenna of an implantable medical device;

rectifying the received far field radiative signal at the implantable medical device to provide a voltage;

charging a charge storage element of the implantable medical device responsive to the voltage; and

providing a therapy to a patient using a therapy delivery unit of the implantable medical device, wherein the therapy delivery unit receives power from the charge storage element.

18. The method of claim 17, wherein rectifying the received far field radiative signal comprises multiplying a rectified voltage to provide the voltage.

19. The method of claim 17, wherein rectifying the received far field radiative signal further comprises increasing the provided voltage at a DC-to-DC converter.

20. The method of claim 17, further comprising detecting when charge stored at the charge storage element satisfies a threshold.

21. The method of claim 20, wherein a control unit is configured to cause the therapy delivery unit to provide the therapy in response to detecting that the threshold is satisfied.

22. The method of claim 17, wherein a distance between the antenna and a transmitter transmitting the far field radiative signal is greater than 0.1 meters.

23. A system comprising:

an external transmitter configured to transmit a far field radiative signal; and

an implantable medical device configured to receive the far field radiative signal, the implantable medical device comprising;

a voltage rectifier configured to rectify the received far field radiative signal to provide a rectified voltage signal;

a charge storage device operative to receive the rectified voltage signal and to store charge responsive to the rectified voltage signal; and

a pulse generator powered by the charge storage device, the pulse generator operative to generate an electrical stimulation signal to stimulate a target tissue of a patient.

24. The system of claim 23, wherein the far field radiative signal has a frequency within a range of approximately 100 MHz to approximately 5.8 GHz.

25. The system of claim 23, wherein the far field radiative signal is a pulsed signal.

26. The system of claim 25, wherein the pulsed signal has an average transmission power of 1 watt or less and an instantaneous transmission power of 5 watts or less.

27. The system of claim 23, wherein the far field radiative signal is transmitted over a distance of at least twice a wavelength of the far field radiative signal.

28. The system of claim 23, wherein the far field radiative signal is transmitted over a distance of 0.1 meters or more.

29. The system of claim 23, wherein the far field radiative signal has a free-space path loss that is proportional to a free-space path distance squared.