TIME REMAINING TO CHARGE AN IMPLANTABLE MEDICAL DEVICE, CHARGER INDICATOR, SYSTEM AND METHOD THEREFORE

• US 20090273318A1
• Filed: 04/30/2008
• Published: 11/05/2009
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Rondoni, John C., Davis, Jon P., Sahasrabudhe, Rajeev M., Bright, Kevin L.
• Granted Patent: US 8,193,766 B2
• Time in Patent Office: Days
• US Class Current: 320/149
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition

Abstract

System and method for estimating a time to recharge a rechargeable power source of an implantable medical device. A plurality of measured parameters relating to the implantable medical device and an external charging device are applied to a model of recharging performance and an estimate is provided to a patient, perhaps in advance of charging. Once charging has begun, updated estimates can be provided until charging is complete. Once charging is complete, the model may be updated to reflect any differences in the estimated time to complete charging and the actual time required to complete charging. The model may be based on limitations to the rate at which charge may be transferred to the rechargeable power source over a plurality of intervals.

Claims

1. A system, comprising:

an implantable medical device having a rechargeable power source, said rechargeable power source having a charge level and a charge capacity;

an external charger operatively coupled to said implantable medical device, said external charger having an external power source, said external charger charging said rechargeable power source;

electronic componentry determining an estimated time until said charge level reaches a predetermined level following commencement of a recharge session based on a plurality of measured parameters and a predetermined recharge model; and

a user output operatively coupled to said external charger and to said electronic componentry, outputting said time to a user;

wherein said predetermined recharge model is updated based on an actual time to recharge compared with said estimated time.

2. The system as in claim 1 wherein said external charger further comprises a primary coil, wherein said implantable medical device further comprises a secondary coil, and wherein said external charger operatively couples to said implantable medical device when said primary coil is placed in proximity of said secondary coil.

3. The system as in claim 2 wherein said plurality of measured parameters comprise at least one of:

voltage over said primary coil;

current through said primary coil;

voltage over said external power source;

voltage over said implantable power source;

current through said implantable power source;

voltage over said secondary coil;

current through said secondary coil;

temperature;

charge stored in said external power source;

charge capacity of said external power source;

temperature of said external charger; and

temperature of said implantable medical device.

4. The system as in claim 3 wherein said electronic componentry further determines a plurality of charging rates based on said plurality of measured parameters and said recharge model.

5. The system as in claim 4 wherein said predetermined recharge model has a plurality of intervals, each individual one of said plurality of intervals having an individual one of a plurality of limiting factors, said plurality of charging rates being based, at least in part, on at least one of said plurality of limiting factors.

6. The system as in claim 5 wherein said electronic componentry determines said time further based on said lowest individual one of said plurality of charging rates for each of said plurality of intervals.

7. A system, comprising:

an implantable medical device having a rechargeable power source, said rechargeable power source having a charge level and a charge capacity;

an external charger having;

an external power source operatively coupled to said implantable medical device and charging said rechargeable power source;

an electronic componentry determining an estimated time until said charge level reaches a predetermined level following commencement of a charge session by determining a plurality of charging rates based on a plurality of measured parameters and a predetermined recharge model, said predetermined recharging model having a plurality of intervals, each individual one of said plurality of intervals having an individual one of a plurality of limiting factors, said plurality of charging rates being based, at least in part, on at least one of said plurality of limiting factors, wherein said charging of said rechargeable power source occurs at a lowest individual one of said plurality of charging rates; and

a user output operatively coupled to said external device and to said electronic componentry, outputting said time to a user;

wherein said predetermined recharge model is updated based on an actual time to recharge compared with said estimated time.

8. The system as in claim 7 wherein said external charger further comprises a primary coil, wherein said implantable medical device further comprises a secondary coil, and wherein said external charger operatively couples to said implantable medical device when said primary coil is placed in proximity of said secondary coil.

9. The system as in claim 8 wherein said plurality of measured parameters comprise at least one of:

voltage over said primary coil;

current through said primary coil;

voltage over said external power source;

voltage over said implantable power source;

current through said implantable power source;

voltage over said secondary coil;

current through said secondary coil;

temperature;

charge stored in said external power source;

charge capacity of said external power source;

temperature of said external charger; and

temperature of said implantable medical device.

10. A method for determining an estimated time to charge an implantable medical device having a rechargeable power source, said rechargeable power source having a charge level and a charge capacity and being operatively coupled to an external charger, comprising the steps of:

determining said estimated time until said charge level reaches a predetermined level following commencement of a recharge session, based on a plurality of measured parameters and a predetermined recharge model;

charging said rechargeable power source using said external charger, wherein said determining step occurs during said charging step;

outputting said estimated time to a user; and

updating said predetermined recharge model based on an actual time to recharge compared with said estimated time.

11. The method as in claim 10 wherein said external charger has a primary coil, said implantable medical device has a secondary coil, and wherein said external charger and said implantable medical device are operatively coupled when said primary coil is placed in proximity of said secondary coil.

12. The method as in claim 11 wherein said plurality of measured parameters comprise at least one of:

voltage over said primary coil;

current through said primary coil;

voltage over said external power source;

voltage over said implantable power source;

current through said implantable power source;

voltage over said secondary coil;

current through said secondary coil;

temperature;

charge stored in said external power source;

charge capacity of said external power source;

temperature of said external charger; and

temperature of said implantable medical device.

13. The method as in claim 12, further comprising the step of determining a plurality of charging rates based on said plurality of measured parameters and said recharge model.

14. The method as in claim 13 wherein said predetermined recharge model has a plurality of intervals, each individual one of said plurality of intervals having an individual one of a plurality of limiting factors, said plurality of charging rates being based, at least in part, on at least one of said plurality of limiting factors.

15. The method as in claim 14 wherein said determining step is further based on said lowest individual one of said plurality of charging rates for each of said plurality of intervals.

16. A method for determining an estimated time to charge an implantable medical device having a rechargeable power source, said rechargeable power source having a charge level and a charge capacity, said rechargeable power source being operatively coupled to an external charger, comprising the steps of:

charging said rechargeable power source using said external charger at a lowest individual one of a plurality of charging rates determined by a plurality of measured parameters and a predetermined recharge model, wherein said predetermined recharge model has a plurality of intervals, each individual one of said plurality of intervals having an individual one of a plurality of limiting factors, said plurality of charging rates being based, at least in part, on at least one of said plurality of limiting factors;

determining said estimated time until said charge level reaches a predetermined level following commencement of a recharge session based on said plurality of measured parameters and said predetermined recharge model;

outputting said estimated time to a user; and

updating said predetermined recharge model based on an actual time to recharge compared with said estimated time.

17. The method as in claim 16 wherein said external charger has a primary coil, said implantable medical device has a secondary coil, and wherein said external charger and said implantable medical device are operatively coupled when said primary coil is placed in proximity of said secondary coil.

18. The method as in claim 17 wherein said plurality of measured parameters comprise at least one of:

voltage over said primary coil;

current through said primary coil;

voltage over said external power source;

voltage over said implantable power source;

current through said implantable power source;

voltage over said secondary coil;

current through said secondary coil;

temperature;

charge stored in said external power source;

charge capacity of said external power source; and

capacity fade of said rechargeable power source.

19. The method as in claim 18 wherein said determining step is further based on said lowest individual one of said plurality of charging rates for each of said plurality of intervals.