EVENT-BASED BATTERY MONITOR FOR IMPLANTABLE DEVICES

• US 20100010559A1
• Filed: 06/26/2009
• Published: 01/14/2010
• Est. Priority Date: 07/09/2008
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: ZHANG, Cheng, Maile, Keith R.
• Granted Patent: US 8,131,365 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• CPC Class Codes: A61N 1/3708 for power depletion
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3835 involving only voltage measurements

Abstract

A remaining charge capacity of a battery having an initial charge capacity is monitored. The battery powers a remote implantable medical device (IMD) that includes an active state, during which the remote IMD performs at least one function, and an inactive state, during which the remote IMD performs no functions. An active state charge consumption is computed based on stored parameters associated with an operational charge consumption for each function, and an inactive state charge consumption is computed based on a leakage current associated with the inactive state and a time the remote IMD is in the inactive state. The active state charge consumption and inactive state charge consumption are subtracted from the initial charge capacity to determine the remaining charge capacity.

Claims

1. A cardiac rhythm management system comprising:

a remote physiological sensor powered by a battery having an initial charge capacity, wherein the remote physiological sensor includes an active state, during which the remote physiological sensor performs at least one function, and an inactive state, during which no functions are performed by the remote physiological sensor; and

a pulse generator configured to communicate with the remote physiological sensor via telemetry, wherein the pulse generator includes a memory operable to store parameters associated with charge consumption for each function performed by the remote physiological sensor and a leakage current associated with the inactive state, wherein the pulse generator further includes a processor operable to determine an active state charge consumption based on the stored parameters and an inactive state charge consumption based on the stored leakage current and a time the device is in the inactive state, and wherein the processor is further operable to subtract the active state charge consumption and inactive state charge consumption from the initial charge capacity to determine a remaining charge capacity of the battery.

2. The cardiac rhythm management system of claim 1, wherein the remote physiological sensor is operable to transmit a voltage of the battery to the pulse generator.

3. The cardiac rhythm management system of claim 2, wherein the processor is further operable to determine the remaining charge capacity based on the voltage of the battery.

4. The cardiac rhythm management system of claim 1, wherein the memory is operable to store operational charge consumption information for a function having a fixed duration.

5. The cardiac rhythm management system of claim 1, wherein, for a function having a fixed duration, the memory is operable to store information related to an amount of charge consumption of the fixed-duration function, and wherein the processor is operable to multiply the stored information associated with the fixed-duration function by a number of occurrences of the fixed-duration function during the active state to determine the active state charge consumption.

6. The cardiac rhythm management system of claim 1, wherein, for a function having a variable duration, the memory is operable to store information related to a current consumption of the variable-duration function, and wherein the processor is operable to multiply the stored information associated with the variable-duration function by a time the variable-duration function is active during the active state to determine the active state charge consumption.

7. The cardiac rhythm management system of claim 1, wherein the pulse generator is further operable to communicate battery status information for the remote physiological sensor to a remote computer.

8. A method for monitoring a remaining charge capacity of a battery having an initial charge capacity, wherein the battery powers a remote implantable medical device (IMD) that includes an active state, during which the remote IMD performs at least one function, and an inactive state, during which the remote IMD performs no functions, the method comprising:

activating the remote IMD from the inactive state to perform one or more functions;

receiving data related to the one or more functions from the remote IMD;

returning the remote IMD to the inactive state;

computing an active state charge consumption based on stored parameters associated with an operational charge consumption for each function;

computing an inactive state charge consumption based on a leakage current associated with the inactive state and a time the remote IMD is in the inactive state; and

subtracting the active state charge consumption and inactive state charge consumption from the initial charge capacity.

9. The method of claim 8, wherein, for a function having a fixed duration, determining the active state charge consumption comprises:

multiplying stored operational charge consumption information associated with the fixed-duration function by a number of occurrences of the fixed-duration function during the active state.

10. The method of claim 8, wherein, for a function having a variable duration, determining the active state charge consumption comprises:

multiplying stored operational current information associated with the variable-duration function by a time the variable-duration function is active during the active state.

11. The method of claim 8, and further comprising:

receiving data related to a voltage of the battery.

12. The method of claim 11, wherein the receiving step comprises receiving data related to the voltage of the battery periodically.

13. The method of claim 11, wherein the remaining charge capacity is further monitored based on the voltage of the battery.

14. A system for monitoring a remaining charge capacity of a battery in an implantable device, wherein the battery has an initial charge capacity, and wherein the implantable device includes an active state, during which the implantable device performs at least one function, and an inactive state, during which the implantable device performs no functions, the system comprising:

a memory operable to store parameters associated with charge consumption for each function and a leakage current associated with the inactive state; and

a processor operable to determine an active state charge consumption based on the stored parameters and an inactive state charge consumption based on the stored leakage current and a time the device is in the inactive state, wherein the processor is further operable to subtract the active state charge consumption and inactive state charge consumption from the initial charge capacity to determine the remaining charge capacity.

15. The system of claim 14, wherein the implantable device is operable to transmit a voltage of the battery to the processor.

16. The system of claim 15, wherein the processor is further operable to determine the remaining charge capacity based on the voltage of the battery.

17. The system of claim 14, wherein, for a function having a fixed duration, the memory is operable to store information related to an amount of charge consumption of the fixed-duration function, and wherein the processor is operable to multiply the stored information associated with the fixed-duration function by a number of occurrences of the fixed-duration function during the active state to determine the active state charge consumption.

18. The system of claim 14, wherein, for a function having a variable duration, the memory is operable to store information related to a current consumption of the variable-duration function, and wherein the processor is operable to multiply the stored information associated with the variable-duration function by a time the variable-duration function is active during the active state to determine the active state charge consumption.

19. The system of claim 14, and further comprising:

a telemetry module operable to communicate battery status information for the implantable device to a remote computer.

20. The system of claim 14, wherein the memory and the processor are included in a pulse generator.