Patent Document ID: 9375152
Application ID: 13767362
Patent Flag: 1

Claim One:
1. An apparatus comprising: a sensor configured to sense a heart sound signal of a patient; and a heart sound processor circuit, configured to: receive the heart sound signal; obtain an initial heart sound expectation window function that describes a heart sound timing, of a specified type of heart sound, as a first function of at least one physiologic variable, the physiologic variable comprising at least one of intrinsic vs. non-intrinsic beat, respiration rate, index of circadian timing, or posture, and the first function comprising at least one characteristic parameter that describes a value of the heart sound timing of the specified type of heart sound at a specified value of the physiologic variable; detect a patient heart sound, of the specified type, using the initial heart sound expectation window function and the heart sound signal; update the at least one characteristic parameter using timing information from the detected patient heart sound of the specified type; and provide an updated heart sound expectation window function, using the updated at least one characteristic parameter, for subsequent use in detecting a patient heart sound of the specified type, the updated heart sound expectation window function describing the heart sound timing, of the specified type of heart sound, as a second function different from the first function of the at least one physiologic variable.