Wearable Heart Sound and EKG Recorder

Acute congestive heart failure is a leading cause of morbidity and mortality. Patients often undergo repeated hospitalizations with an annual cost in excess of $32B dollars. Early detection of impending acute congestion allows for pharmaceutical interdiction that prevents hospitalization, improves outcomes, and reduces healthcare spending. A subcutaneous implantable monitoring device that detects impending acute congestive heart failure by using heart sounds may provide a valuable tool that can be used to titrate heart failure medications to prevent acute heart failure requiring hospitalization. The device may be used to measure changes in the intervals between the R-wave and S1 and S2 heart sounds, and to detect evolving S3 and S4 heart sounds consistent with volume overload. The amplitudes of S1 and S3 heart sounds change as heart failure patients\u27 symptoms worsen. Designing a non-invasive, external device, capable of recording heart sounds and EKGs in patients undergoing pharmaceutical regression of acute congestive heart failure in a hospital setting may give important insight into the nature of heart sound and EKG changes that occur in patients during progression of acute heart failure while they lead their day-to-day lives. This thesis details the design of a portable, non-invasive device, worn externally on the left-pectoral muscle, capable of continuously recording human EKG signals and heart sounds (through custom MEMS accelerometer technology) over a period of two days. Hardware testing for the scope of this thesis exclusively involved healthy volunteers