Patent ID: 6671552
Filing Date: 2003-12-30
Classification: A61N

Abstract:
In an implantable medical device (IMD) that is powered by a battery exhibiting a characteristic voltage drop at any given current drain from a beginning-of-life battery voltage to an elective replacement indicator battery voltage, the IMD imposing a quiescent current drain on the battery and periodically imposes an episodic current drain on the battery in an energy consuming incident including one or more of delivery of a therapy through a therapy delivery channel or monitoring a physiologic condition through a monitoring channel, the quiescent and episodic current drain consuming battery energy that cumulatively causes battery voltage to drop, a method of estimating the remaining life of the battery until battery voltage drops to the elective replacement indicator battery voltage comprising the steps of:periodically measuring battery voltage and averaging a plurality of battery voltage measurements to derive an average measured battery voltage; estimating the estimated past current drain of the IMD comprising an average of the sum of the quiescent current drain and the episodic current drain; and determining the estimated remaining longevity from the measured voltage and the estimated past current drain.