System and method for estimating battery capacity
AssigneeCyberonics, Inc.
InventorsAnthony W. Cowley, Saadat Hussain
Life of this patent
Estimating the term…
Abstract
A method for estimating capacity of a battery in an implantable medical device includes obtaining a characteristic curve of voltage versus resistance for the battery, periodically determining voltage and resistance of the battery, and comparing the resistance with a third derivative function of the characteristic curve, the third derivative function having roots representing near depletion of the battery and end of service of the battery, respectively. Remaining time of service of the battery can also be determined by comparing the resistance value with a curve of battery capacity versus resistance for the battery.
Claims20
A method comprising:
- accessing, at a computing device, data indicating a characteristic relationship between voltage and resistance for a battery of an implantable medical device;
- determining, at the computing device, a voltage value and a resistance value of the battery during a first time interval;
- comparing, at the computing device, the resistance value to one or more values indicated by a third derivative function based on the data indicating the characteristic relationship, wherein the data further indicates a first period corresponding to near depletion of the battery and a second period corresponding to end of service of the battery, and wherein the first period and the second period are based on the third derivative function;
- and
- estimating, at the computing device, one or more future performance characteristics of the battery based on a comparison of the resistance value to the one or more values indicated by the third derivative function.
A computing device comprising:
- a processor;
- and
- a memory accessible to the processor, the memory including instructions that, when executed by the processor, cause the processor to:
- access data indicating a characteristic relationship between voltage and resistance for a battery of an implantable device;
- determine a voltage value and a resistance value of the battery during a first time interval;
- compare the resistance value to one or more values indicated by a third derivative function based on the data indicating the characteristic relationship, wherein the data further indicates a first period corresponding to near depletion of the battery and a second period corresponding to end of service of the battery, and wherein the first period and the second period are based on the third derivative function;
- and
- estimate one or more future performance characteristics of the battery based on a comparison of the resistance values to the one or more values indicated by the third derivative function.
A tangible computer-readable storage device including instructions that, when executed by a processor, cause the processor to:
- access data indicating a characteristic relationship between voltage and resistance for a battery of an implantable device;
- determine a voltage value and a resistance value of the battery in the implantable device during a first time interval;
- compare the resistance value to one or more values indicated by a third derivative function based on the data indicating the characteristic relationship, wherein the data further indicates a first period corresponding to near depletion of the battery and a second period corresponding to end of service of the battery, and wherein the first period and the second period are based on the third derivative function;
- and
- estimate one or more future performance characteristics of the battery based on a comparison of the resistance value to the one or more values indicated by the third derivative function.
Dependencies are inferred from the claim text.