Apparatus and method for exercising a battery for an implantable medical device

1. An implantable medical device for implantation into a patient, comprising:

a battery having an electrode that develops a resistive film;

a low deformation-rate capacitor capable of storing a charge from the battery, the capacitor requiring few or no periodic discharges of the battery for reformation;

means for periodically discharging energy from the battery into the low deformation-rate capacitor to reduce film buildup on the electrode; and

means for optimizing the battery discharge.

2. An implantable medical device according to claim 1 , further comprising a lead for sensing electrical signals of a patient via at least one electrode operatively coupled to the lead.

3. An implantable medical device according to claim 2 , further comprising a status system for monitoring heart activity of the patient through the lead.

4. An implantable medical device according to claim 3 , further comprising a therapy delivery system for delivering electrical energy through the lead to a heart of the patient.

5. An implantable medical device according to claim 1 , further comprising a means for determining time elapsed since a therapy was delivered to a patient or since the battery was at least partially discharged.

6. An implantable medical device according to claim 1 , wherein the battery discharge is greater than about 2.5 Joules.

7. An implantable medical device according to claim 1 , further comprising a means for optimizing the time between discharging the battery.

8. An implantable medical device according to claim 7 , wherein the means for optimizing the battery discharge is dependant upon voltage delay.

9. An implantable cardioverter defibrillator according to claim 1 , further comprising a means for optimizing the time between discharging the battery.

10. An implantable cardioverter defibrillator according to claim 9 , wherein the means for optimizing the battery discharge is dependant upon voltage delay.

11. An implantable cardioverter defibrillator comprising:

a lead for applying electrical energy to the patient;

a battery having an electrode for powering the implantable cardioverter defibrillator, the battery having an electrode that develops a film on it over time due to a lack of battery discharge;

an ICD status system for monitoring heart activity of the patient through the lead;

a therapy delivery system for delivering electrical energy through the lead to a heart of the patient;

a capacitor capable of storing a charge from the battery, the capacitor requiring no periodic discharges of the battery for reformation;

means for periodically discharging the battery to reduce film buildup on the electrode; and

means for otimizing the battery discharge.

12. An implantable cardioverter defibrillator according to claim 11 , further comprising a means for determining elapsed time since a therapy was delivered to a patient or since the battery was discharged to reduce film buildup.

13. An implantable cardioverter defibrillator according to claim 11 , wherein the battery discharge is greater than about 2.5 Joules.

14. A method of exercising a battery of an implantable medical device, comprising:

determining whether a film is disposed on a portion of an electrode of a battery;

discharging the battery a sufficient amount to reduce the film disposed on a portion of the electrode of the battery; and

optimizing energy used during exercising the battery.

15. A method according to claim 14 , further comprising: optimizing a time period, wherein said time period is defined as the amount of time elapsed between consecutive exercising of the battery.

16. A method according to claim 14 , wherein the energy used during exercising the battery is optimized based upon voltage delay during charging of a capacitor.

17. A method according to claim 14 , wherein the energy used during exercising the battery is optimized based upon discharging of the battery.

18. A method according to claim 14 , wherein the battery supplies energy to a capacitor or an electrical resistor to exercise the battery.

19. A method according to claim 18 , wherein the capacitor charged by the battery subsequently powers the device.

20. A method according to claim 14 , wherein the battery is discharged through a resistive load to exercise the battery.

21. A method of exercising a battery of an implantable cardiac defibrillator, comprising:

determining a period of time elapsed since a cardiac therapy was administered to a patient or since a battery exercising session was performed;

resuming normal implantable cardiac defibrillator operation if the last therapy or exercising session was less than a predetermined amount of time; and

charging a capacitor with a predetermined amount of energy if the last therapy or exercising session was performed a greater time than the predetermined time;

wherein the energy used during exercising the battery is optimized by minimizing the amount of energy removed from the battery.

22. A method according to claim 21 , further comprising the step of determining whether the cardiac therapy needs to be administered.

23. A method according to claim 22 , further comprising:

instructing a therapy delivery system to charge the capacitor to deliver the cardiac therapy on a scheduled basis.

24. A method according to claim 21 , wherein the energy used during exercising the battery is optimized by minimizing the amount of energy removed from the battery based on a voltage delay.

25. A method according to claim 24 , wherein a processor executes a software module to optimize energy removal from the battery.

26. A method according to claim 21 , wherein the energy used during exercising the battery is optimized by minimizing the amount of energy removed from the battery based on a capacitor charge time, wherein said capacitor charge time comprises a period of time during which the capacitor is charged to a maximum or rated voltage of said capacitor.

27. A method according to claim 26 , further comprising the step of determining whether the capacitor was charged to the maximum or rate voltage of said capacitor.

28. A computer readable medium for storing instructions for performing a method of exercising a battery of an implantable cardiac defibrillator, comprising:

instructions for determining a period of time elapsed since a cardiac therapy was administered to a patient or since a battery exercising session was performed;

instructions for resuming normal implantable cardiac defibrillator operation if the last therapy or exercising session was less than a predetermined amount of time;

instructions for charging a capacitor with a predetermined amount of energy if the last therapy or exercising session was performed a greater time than the predetermined time; and

instructions for optimizing the energy used during exercising the battery by minimizing the amount of energy removed from the battery.

29. A medium according to claim 28 , further comprising instructions for determining whether the cardiac therapy needs to be administered.

30. A medium according to claim 29 , further comprising instructions for instructing a therapy delivery system to charge the capacitor to deliver the cardiac therapy on a scheduled basis.

31. A medium according to claim 28 , wherein the instructions for optimizing the energy used during exercising the battery comprise instructions for minimizing the amount of energy removed from the battery based on a voltage delay.

32. A medium according to claim 31 , wherein a remote processor executes the instructions for optimizing energy removal from the battery.

33. A medium according to claim 28 , wherein the instructions for optimizing the energy used during exercising the battery comprise instructions for minimizing the amount of energy removed from the battery based on a capacitor charge time, wherein said capacitor charge time comprises a period of time during which the capacitor is charged to a maximum or rated voltage of said capacitor.

34. A medium according to claim 33 , further comprising instructions for determining whether the capacitor was charged to the maximum or rated voltage of said capacitor.