Patent ID: 8718766

Claim:
An activity-responsive implantable medical device comprising: a connector connectable to an implantable medical lead having at least one pacing electrode; a pulse generator connected to the connector and configured to generate pacing pulses to be applied to the at least one pacing electrode; an activity processor configured to receive a sensor signal representative of an activity level of a subject from an activity sensor and determine a current activity level of the subject based on the sensor signal; and a pulse generator controller connected to the pulse generator and configured to control the pulse generator to generate the pacing pulses; wherein the activity processor is further configured to directly determine a time period during which the current activity level determined based on the sensor signal has exceeded a first threshold level; and wherein the pulse generator controller is configured to control the pulse generator to generate pacing pulses at a pacing rate determined based on the current activity level and directly based on a length of the time period such that the pacing rate=f(L A , T A ), wherein L A is the current activity level and T A is the length of the time period.