Patent ID: 7670298

Claim:
An implantable device comprising: a transducer that converts heart sounds into an electrical signal; a control circuit coupled to the transducer, the control circuit configured to receive the electrical signal, identify an S 1 heart sound, convert the S 1 heart sound into morphological data comprising a maximum S 1 amplitude and a minimum S 1 amplitude, and determine and provide, to a user or automated process, a patient status indicator based on an indication of a peak-to-peak difference between the maximum S 1 amplitude and the minimum S 1 amplitude, wherein the patient status indicator is correlative to at least one of contractility or a maximum time rate of change of pressure within a ventricle of a heart during a cardiac cycle; and a housing enclosing the control circuit, the housing defining a volume coextensive with an outer surface of the housing; wherein the transducer is located in a region in or on the housing.