US Patent 7016730 Method of operating implantable medical devices to prolong battery life

A method of conserving power and extending the life of a battery in an implantable rate-responsive cardiac rhythm management device. In accordance with the preferred embodiment, a first physiologic sensor is used to enable a power consuming feature only when the first sensor produces an output falling within a predetermined range and subsequently disables the power consuming feature when the output of the first sensor falls back outside the predetermined range. The first sensor may measure heart rate, physical movement, posture or other parameters and the power consuming feature may comprise further physiologic sensors, a different mode of pacing or a combination thereof.