Charging System for an Implantable Medical Device Employing Magnetic and Electric Fields

• US 20120004709A1
• Filed: 06/20/2011
• Published: 01/05/2012
• Est. Priority Date: 07/01/2010
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Chen, Joey, Ozawa, Robert, Hyun, Joonho, Dronov, Vasily
• Granted Patent: US 9,044,616 B2
• Time in Patent Office: Days
• US Class Current: 607/61
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A base station for passively recharging a battery in an implant without patient involvement is disclosed. The base station can be hand held or may comprise equipment configured to be placed at a fixed location, such as under a bed, on or next to a wall, etc. The base station can generate electric and magnetic fields (E-field and B-field) that couple with an antenna and a receiving coil within the implant to generate a charging current for charging the implant'"'"'s battery. No handling or manipulation on part of the patient is necessary; the implant battery is passively charged whenever the patient is within range of either the magnetic or electric charging fields generated by base station. Charging using the B-field occurs when the IPG is at a relatively short distance from the base station, while charging using the E-field occurs at longer distances. Back telemetry from the implant can inform the base station whether B-field or E-field charging is indicated, and is preferred if possible for its ability to transfer higher amounts of power to the implant.

Claims

1. An external device for charging a battery in an implantable medical device, comprising:

at least one first antenna selectively enabled to generate an electric field for charging the battery in the implantable medical device; and

at least one second antenna selectively enabled to generate a magnetic field for charging the battery in the implantable medical device.

2. The device of claim 1, wherein the at least one first antenna comprises a quarter-wavelength monopole antenna or a half-wavelength dipole antenna.

3. The device of claim 1, wherein the at least one first antenna comprises a wire, patch or slot antenna.

4. The device of claim 1, wherein the at least one second antenna comprises a coil.

5. The device of claim 1, wherein the electric field comprises a first frequency and the magnetic field comprises a second frequency lower than the first frequency.

6. The device of claim 1, wherein the external device is positionable on a floor or wall.

7. The device of claim 1, wherein the electric field is not modulated with data.

8. The device of claim 1, further comprising first demodulation circuitry coupleable to the first antenna for receiving charging information from the implantable medical device, and second demodulation circuitry coupleable to the second antenna for receiving charging information from the implantable medical device.

9. The device of claim 1, further comprising demodulating circuitry for receiving charging information from either or both of the first and second antennas, wherein the charging information is used to enable either the first or second antenna.

10. The device of claim 1, further comprising a third antenna for receiving charging information transmitted from the implantable medical device during generation of either the electric or magnetic fields.

11. The device of claim 1, wherein only one of the first and second antennas are enabled at one time.

12. An implantable medical device, comprising:

a battery;

a first antenna configured to receive an electric field for charging the battery;

a second antenna configured to receive a magnetic field for charging the battery; and

a microcontroller for determining whether either or both of the electric field and the magnetic field have been received at the first or second antennas respectively, and for issuing at least one control signal enabling charging of the battery either by the electric field or the magnetic field.

13. The device of claim 12, further comprising a first rectifier coupled to the first antenna for producing a first DC voltage, and a second rectifier coupled to the second antenna for producing a second DC voltage.

14. The device of claim 13, wherein the microcontroller determines whether either or both of the electric field and the magnetic field have been received at the first or second antennas respectively using first and second DC voltages.

15. The device of claim 13, further comprising charging circuitry, wherein the charging circuitry is responsive to the at least one control signal to select either the first DC voltage or the second DC voltage as the power source for charging the battery.

16. The device of claim 12, wherein the at least one control signal enables a transmitter for transmitting charging information from the implantable medical device.

17. The device of claim 16, wherein the transmitter transmits the charging information from either the first or second antenna.

18. The device of claim 12, wherein the charging information comprises a voltage of the battery.

19. The device of claim 12, wherein the first antenna comprises an electrode lead coupled to an electrode for providing stimulation to a patient'"'"'s tissue.

20. An implantable medical device system, comprising:

an implantable medical device, comprising

a battery,

a first antenna for receiving an electric field for charging the battery, and

a second antenna for receiving a magnetic field for charging the battery; and

an external device, comprising

a third antenna for generating the electric field for charging the battery, and

a fourth antenna for generating the magnetic field for charging the battery.

21. The system of claim 20, further comprising an external charger separate from the external device comprising a fifth antenna for generating a magnetic field received at the second antenna for charging the battery.

22. The system of claim 20, further comprising an external controller separate from the external device comprising a sixth antenna for communicating data with the first antenna.

23. The system of claim 20, wherein the second and fourth antennas comprise coils.

24. The system of claim 23, wherein the first and third antennas comprise quarter- or half-wavelength antennas.

25. The system of claim 20, wherein only one of the third or fourth antennas generates their respective fields at one time.

26. The system of claim 25, wherein the third antenna generates the electric field when the implantable medical device are separated by more than a distance, and wherein the fourth antenna generates the magnetic field when the implantable medical device are separated by less than the distance.

27. A method for charging a battery in an implantable medical device using an external device, comprising:

electronically determining at the external device whether the battery in the implantable medical device can be charged by the external device using a magnetic field;

if the battery in the implantable medical device can be charged by the external device using a magnetic field, automatically generating a magnetic field at the external device to charge the battery; and

if the battery in the implantable medical device cannot be charged by the external device using a magnetic field, automatically generating an electric field at the external charger to charge the battery.

28. The method of claim 27, wherein the external device determines whether the battery in the implantable medical device can be charged by the magnetic field in accordance with data received from the implantable medical device.

29. The method of claim 28, wherein the data comprises a voltage of the battery or data indicative of the coupling between the external device and the implantable medical device.

30. The method of claim 27, wherein the electric field and magnetic field are generated using separate antennas in the external device.

31. The method of claim 30, wherein the electric field comprise a first frequency, and wherein the magnetic field comprises a second frequency lower than the first frequency.

32. A method for charging a battery in an implantable medical device using an external device, comprising:

(a) generating a magnetic field at the external device;

(b) determining at the external device whether the implantable medical device is receiving the magnetic field;

(c) if the implantable medical device is receiving the magnetic field, continuing to generate the magnetic field at the external device to charge the battery; and

(d) if the implantable medical device is not receiving the magnetic field, generating an electric field at the external charger to charge the battery.

33. The method of claim 32, further comprising

(e) if the external device is generating an electric field in step (d), periodically ceasing the generation of the electric field to generate a magnetic field at the external device;

and

(f) repeating steps (b) through (e).

34. The method of claim 32, wherein the electric field and magnetic field are generated using separate antennas in the external device.

35. The method of claim 34, wherein the electric field comprises a first frequency, and wherein the magnetic field comprises a second frequency lower than the first frequency.

36. The method of claim 32, wherein step (a) occurs automatically when the external device is powered on.