Time to next recharge session feedback while recharging an implantable medical device, system and method therefore

• US 8,751,010 B2
• Filed: 04/30/2008
• Issued: 06/10/2014
• 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., Bright, Kevin L., Sahasrabudhe, Rajeev M.
• Primary Examiner(s): BOCKELMAN, MARK
• Application Number:
  US12/112,719
• Publication Number:
  US 20090276015A1
• Time in Patent Office: 2,232 Days
• Field of Search: 607/33, 607/61, 607/32, 607/60, 320/132, 320/DIG.21
• US Class Current: 607/61
• CPC Class Codes: A61N 1/3708 for power depletion
• 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

Abstract

A system and method for determining, during a recharge session, an amount of time until a subsequent recharge session is required to charge a rechargeable power source of an implantable medical device. A model allows a determination of the time until recharge without suspending charging during the recharge session by basing the determination on an initial measured battery voltage and a present current into the rechargeable power source. Alternatively, charging is suspended during the recharge session, and voltage measurements are taken, after which time charging is resumed, without patient input or suspending the recharge session.

Claims

1. A recharge management system for use during a recharging session, comprising;

an implantable medical device having a rechargeable power source;

an external charger configured to charge said rechargeable power source when placed in proximity to said implantable medical device;

electronic componentry, operatively coupled to said implantable medical device, configured to determine a recharge interval from a present time until a time for next recharge should said recharging session not continue, said recharge interval being an interval until a recharge time when a charge level of a rechargeable power source of said implantable medical device reaches a value at which recharging of said rechargeable power source is indicated; and

a user output, operatively coupled to said electronic componentry, configured to communicate said recharge interval to a user.

2. The system as in claim 1 wherein said electronic componentry determines said recharge interval by applying a model.

3. The system as in claim 2 wherein said electronic componentry is further configured to measure an initial power source voltage of said rechargeable power source before said external charger begins to charge said rechargeable power source, and wherein said implantable medical device further comprises a current meter, said current meter configured to measure current to said rechargeable power source, and wherein said model utilizes said initial power source voltage and said measured current to determine said recharge interval.

4. The system as in claim 1 wherein said rechargeable power source has a power source voltage, a charge capacity and a charge level, and wherein said electronic componentry is further configured to:

measure said power source voltage during a time in which said external charger has suspended charging of said rechargeable power source;

determine said charge level as a function of said power source voltage and said charge capacity; and

determine said recharge interval based on said charge level.

5. The system as in claim 1 wherein said recharge interval is determined based on a present programmed rate.

6. The system as in claim 1 wherein said recharge interval is determined based on a past programmed rate.

7. The system as in claim 1 wherein said recharge interval is determined based on a present programmed rate and a past programmed rate.

8. The system as in claim 7 wherein said implantable medical device has a programmed therapeutic output having a programmed rate, and wherein said recharge interval is further determined based on said programmed rate.

9. The system as in claim 8 further comprising a user input, wherein said user inputs via said user input a prospective therapeutic output having a prospective rate, and wherein said recharge interval is determined based on said prospective rate should said recharging session not continue.

10. The system as in claim 1 further comprising a user input wherein said user inputs a desired time interval, wherein said rechargeable power source further comprises a present charge level, and wherein said electronic componentry further determines an estimated time to charge said rechargeable power source based on said present charge level and said desired time interval.

11. The system as in claim 10 wherein said user input is a component of said external charger.

12. The system as in claim 1 wherein said electronic componentry is a component of said implantable medical device.

13. The system as in claim 1 wherein said electronic componentry is a component of said external charger.

14. The system as in claim 1 wherein said user output is a component of said external charger.

15. A device implemented method for determining a recharge interval, said recharge interval being an interval from a present time until a recharge time when a charge level of a rechargeable power source of an implantable medical device reaches a value at which recharging of said rechargeable power source is indicated, comprising the steps of:

charging said rechargeable power source with an external charger during a recharging session;

determining, during said recharging session, said recharge interval should said recharging session not continue; and

outputting said recharge interval to a user.

16. The method as in claim 15 wherein said determining step determines said recharge interval by using a model.

17. The method as in claim 16 further comprising the step of measuring an initial power source voltage of said rechargeable power source before said charging step begins, and wherein said charging step further comprises measuring a measured current to said rechargeable power source, and wherein said model utilizes said initial power source voltage and said measured current to determine said recharge interval.

18. The method as in claim 15 wherein said rechargeable power source has a power source voltage, a charge capacity and a charge level, and wherein said determining step further comprises:

suspending said charging step;

measuring said power source voltage;

recommencing said charging step,

determining said charge level as a function of said power source voltage and said charge capacity; and

determining said recharge interval based on said charge level.

19. The method as in claim 15 wherein said recharge interval is determined based on a present programmed rate.

20. The method as in claim 15 wherein said recharge interval is determined based on a past programmed rate.

21. The method as in claim 15 wherein said recharge interval is determined based on a present programmed rate and a past programmed rate.

22. The method as in claim 21 wherein said implantable medical device has a programmed therapeutic output having a programmed rate, and wherein said recharge interval is further determined based on said programmed rate.

23. The method as in claim 22 further comprising the step of selecting, by said user, a prospective therapeutic output having a prospective rate, and wherein said determining step determines said recharge interval based on said prospective rate should said recharging session not continue.

24. The method as in claim 15 wherein said rechargeable power source further comprises a present charge level, further comprising the step of inputting, by said user, a desired time interval, and further comprising the step of determining an estimated time to charge said rechargeable power source based on said present charge level and said desired time interval.