Far field radiative powering of implantable medical therapy delivery devices

Patent metadata

Field	Value
Publication number	US-9492678-B2
Application number	US-201213433907-A
Country	US
Kind code	B2
Filing date	Mar 29, 2012
Priority date	Jul 14, 2011
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

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.

First claim

What is claimed is:

1. A system comprising:
an external transmitter that transmits a pulsed far field radiative signal; and
an implantable medical device comprising:
an antenna configured to receive the pulsed far field radiative signal, wherein a power of the pulsed far field radiative signal is inversely proportional to a square of a distance between the antenna and a transmitter of the pulsed far field radiative signal;
a voltage rectifier configured to rectify the pulsed 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 system 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 system of claim 1 , the implantable medical device 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 system of claim 1 , wherein the voltage rectifier comprises a voltage multiplier.

5. The system of claim 4 , the implantable medical device 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 system of claim 1 , wherein the voltage rectifier comprises Schottky diodes.

7. The system 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 system of claim 1 , the implantable medical device further comprising a threshold detector coupled to the charge storage element, wherein the threshold detector is configured to enable the therapy delivery unit to deliver the therapy responsive to detecting that the charge stored at the charge storage element satisfies a charge threshold.

9. The system of claim 1 , wherein the external transmitter transmits the pulsed far field radiative signal at 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 system of claim 1 , wherein the external transmitter transmits the pulsed far field radiative signal over a distance of at least twice a wavelength of the pulsed far field radiative signal.

11. The system of claim 1 , wherein the external transmitter transmits the pulsed far field radiative signal over a distance of 0.1 meters or more.

12. The system of claim 1 , wherein the external transmitter transmits the pulsed far field radiative signal with a free-space path loss that is proportional to a free-space path distance squared.

13. The system of claim 1 , wherein the external transmitter transmits the pulsed far field radiative signal at an instantaneous transmission power of 5 watts or less.

14. The system of claim 13 , wherein the external transmitter transmits the pulsed far field radiative signal at a duty cycle of 10% or less.

15. The system of claim 1 , wherein the charge storage element has a charge storage capacity that is less than a quantity of charge used by the therapy delivery unit to deliver the therapy to the patient during a period of 24 hours or less.

16. The system of claim 1 , wherein the charge storage element has a charge storage capacity that is sufficient to enable the therapy delivery unit to deliver only a single treatment of the therapy to the patient.

17. A method comprising:
receiving, at an antenna of an implantable medical device a pulsed far field radiative signal, wherein a power of the pulsed far field radiative signal is inversely proportional to a square of a distance between the antenna and a transmitter of the pulsed far field radiative signal;
rectifying the received pulsed 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 pulsed far field radiative signal comprises multiplying a rectified voltage to provide the voltage.

19. The method of claim 17 , wherein rectifying the received pulsed 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 pulsed far field radiative signal is greater than 0.1 meters.

23. A system comprising:
an external transmitter that transmits a pulsed far field radiative signal at an average transmission power of 1 watt or less; and
an implantable medical device, the implantable medical device comprising:
an antenna configured to receive the pulsed far field radiative signal;
a voltage rectifier configured to rectify the received pulsed 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;
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; and
wherein a power of the pulsed far field radiative signal is inversely proportional to a square of a distance between the antenna and a transmitter of the pulsed far field radiative signal.

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

25. The system of claim 23 , further comprising a threshold detector coupled to the charge storage device, wherein the threshold detector is configured to enable the pulse generator to generate the electrical stimulation signal responsive to detecting that the charge stored at the charge storage device satisfies a charge threshold.

26. The system of claim 23 , wherein the external transmitter transmits the pulsed far field radiative signal at an instantaneous transmission power of 5 watts or less.

27. The system of claim 23 , wherein the external transmitter transmits the pulsed far field radiative signal over a distance of at least twice a wavelength of the pulsed far field radiative signal.

28. The system of claim 23 , wherein the external transmitter transmits the pulsed far field radiative signal over a distance of 0.1 meters or more.

29. The system of claim 23 , wherein the external transmitter transmits the pulsed far field radiative signal with a free-space path loss

Assignees

• Chow Eric Y
• Cyberonics Inc

Inventors

• Chow Eric Y

Classifications

• A61N1/3787 Primary

  from an external energy source · CPC title

• A61N1/40 Primary

  Applying electric fields by inductive or capacitive coupling (microwave apparatus A61N5/00); {Applying radio-frequency signals} · CPC title

• A61N1/3782

  producing a voltage above the power source level · CPC title