Automatic On-Off Charger for an Implantable Medical Device

• US 20170143981A1
• Filed: 02/03/2017
• Published: 05/25/2017
• Est. Priority Date: 01/16/2012
• Status: Abandoned Application

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Aghassian, Daniel
• Application Number:
  US15/424,365
• Publication Number:
  US 20170143981A1
• Time in Patent Office: Days
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

An external charger for an implantable medical device is disclosed which can automatically detect an implant and generate a charging field. The technique uses circuitry typically present in an external charger, such as control circuitry, a Load Shift Keying (LSK) demodulator, and a coupling detector. An algorithm in the control circuitry periodically issues charging fields of short duration in a standby mode. If the coupling detector detects the presence of a conductive material, the algorithm issues a listening window during which a charging field is generated. If an LSK reply signal is received at the LSK demodulator, the external charger can charge the implant in a normal fashion. If a movement signature is detected at the LSK demodulator indicative of a predetermined user movement of the external charger, a charging field is issued for a set timing period, to at least partially charge the IPG battery to restore LSK communications.

Claims

1. A charger, comprising:

a coil; and

control circuitry configured to automatically provide power to an implantable medical device (IMD) in the charger'"'"'s vicinity by;

evaluating a voltage across the coil or a current through the coil during one or more periodic activations of the coil; and

energizing the coil to provide power to the IMD when the voltage or the current indicates that the IMD is possibly in the charger'"'"'s vicinity.

2. The charger of claim 1, wherein the control circuitry comprises a coupling detector that compares the voltage across the coil to a threshold voltage.

3. The charger of claim 2, wherein the threshold voltage is dependent upon one or more charging parameters.

4. The charger of claim 2, wherein the control circuitry determines that the IMD is possibly in the charger'"'"'s vicinity when the voltage across the coil is less than the threshold voltage for a plurality of consecutive periodic activations of the coil.

5. The charger of claim 1, wherein the control circuitry is further configured to generate a user alert when the voltage or the current indicate that the IMD is possibly in the charger'"'"'s vicinity.

6. The charger of claim 1, wherein the control circuitry is further configured to de-energize the coil at the end of a first time period unless a verification that the IMD is in the charger'"'"'s vicinity is received.

7. The charger of claim 6, wherein the verification is an LSK signal reflected to the charger by the IMD.

8. The charger of claim 6, wherein the verification is an indication of a predefined movement of the charger by a user.

9. The charger of claim 6, wherein the control circuitry is further configured to modify the evaluation of the voltage or the current when the coil is de-energized a predetermined number of consecutive times.

10. A method, comprising:

automatically providing power to an implantable medical device (IMD) from a coil in a charger by;

evaluating a voltage across the coil or a current through the coil during one or more periodic activations of the coil; and

energizing the coil to provide power to the IMD when the voltage or the current indicates that the IMD is possibly in the charger'"'"'s vicinity.

11. The method of claim 10, wherein evaluating the voltage across the coil comprises comparing the voltage across the coil to a threshold voltage.

12. The method of claim 11, wherein the threshold voltage is dependent upon one or more charging parameters.

13. The method of claim 11, wherein the coil is energized when the voltage across the coil is less than the threshold voltage for a plurality of consecutive periodic activations of the coil.

14. The method of claim 10, further comprising generating a user alert when the voltage or the current indicate that the IMD is possibly in the charger'"'"'s vicinity.

15. The method of claim 10, further comprising de-energizing the coil at the end of a first time period unless a verification that the IMD is in the charger'"'"'s vicinity is received.

16. The method of claim 15, wherein the verification is an LSK signal reflected to the charger by the IMD.

17. The method of claim 15, wherein the verification is an indication of a predefined movement of the charger by a user.

18. The method of claim 15, further comprising modifying the evaluation of the voltage or the current when the coil is de-energized a predetermined number of consecutive times.

19. A charger, comprising:

a coil;

means for evaluating a voltage across the coil or a current through the coil during one or more periodic activations of the coil; and

means for automatically energizing the coil to provide power to the IMD when the voltage or the current indicates that the IMD is possibly in the charger'"'"'s vicinity.

20. The charger of claim 19, wherein the means for evaluating the voltage across the coil comprise means for comparing the voltage across the coil to a threshold voltage.