Patent Number: 7,711,426

Title: Power supply monitoring for an implantable device

Abstract: A method and an apparatus for determining a time period remaining in a useful life of an energy storage device in an implantable medical device. The method may include measuring a voltage of the energy storage device to produce a measured voltage, and comparing the measured voltage to a transition voltage. While the measured voltage is greater than or equal to the transition voltage, the time period remaining in the energy storage device's useful life is approximated based upon a function of charge depleted. While the measured voltage is less than the transition voltage, the time period remaining in the energy storage device's useful life is approximated based upon a higher order polynomial function of the measured voltage. The transition voltage corresponds to a predetermined point on a energy storage device voltage depletion curve representing the voltage across the energy storage device over time.

Inventors: Armstrong; Randolph K. (Houston, TX), Armstrong; Scott A. (Danbury, TX), Inman; D. Michael (Gainesville, FL), Scott; Timothy L. (Sugar Land, TX)

Assignee: Cyberonics, Inc.

International Classification: A61N 1/00 (20060101)

Expiration Date: 5/04/12018