Patent ID: 7431699

Claim:
A heart sound detection system, comprising: a cardiac signal input to receive a cardiac signal indicative of ventricular events; an acoustic signal input to receive an acoustic signal indicative of at least second heart sounds (S 2 ) and third heart sounds (S 3 ); and a heart sound detector coupled to the cardiac signal input and the acoustic signal input, the heart sound detector including: an S 2 window generator to generate an S 2 window after a first predetermined delay starting with each of the ventricular events; an S 2 detector to detect S 2 using an S 2 threshold during the S 2 windows; an S 3 window generator, coupled to the S 2 detector, to generate an S 3 window after a second predetermined delay starting with each of the detected S 2 ; an S 3 detector to detect S 3 using an S 3 threshold during the S 3 windows; a measurement module to detect an acoustic energy using the acoustic signal; and an S 3 threshold generator adapted to determine the S 3 threshold based on the acoustic energy.