Patent ID: 8060201

Claim:
An implantable medical device comprising: a pulse generator configured to emit cardiac stimulating pacing pulses; a cardiac lead connected to said pulse generator and configured for placement relative to cardiac tissue of a patient to deliver said pacing pulses to said cardiac tissue; an acoustic energy sensor that senses acoustic energy in predetermined periods of a cardiac cycle during successive heart cycles of the patient, and that emits successive sensed signals respectively representing said acoustic energy in said predetermined periods during successive heart cycles; a signal processor supplied with said sensed signals and configured to extract an extracted signal representing the S 1 heart sound from each of said successive sensed signals, and to calculate an energy value associated with each extracted signal representing the S 1 heart sound; a storage unit; and a controller in communication with said signal processor and said storage unit and said pulse generator, and being configured to operate said pulse generator to control emission of said cardiac stimulating pacing pulses from said pulse generator, said controller being configured to, at selected times, initiate an optimization procedure to iteratively modify emission of said cardiac stimulating pacing pulses to optimize an interval selected from the group consisting of a PV interval and a AV interval with respect to said energy value, by setting said interval to a first interval length and iteratively reducing said first interval length and storing, in said storage unit, successively extracted signals representing the S 1 heart sound and the respective energy values corresponding thereto, and successively comparing said stored successive energy values, and stopping reduction of said first interval length when a comparison between successive energy values indicates an increase in the energy value of the associated extracted signal representing the S 1 heart sound, and operating said pulse generator, until a next optimization procedure, to cause said pulse generator to emit said cardiac stimulating pacing pulses with said first interval length that resulted in said increase, as an optimized length of said interval.