Design and Development of Digital Stethoscope

This research explores the fusion of cardiac auscultation and phonocardiography (PCG) to enhance cardiac acoustic analysis. Traditional stethoscopes face limitations, including the need for expertise to discern abnormalities based solely on auditory information and the challenge of isolating heart sounds from background noise. We introduce a robust hardware and software framework for signal acquisition and processing, effectively reducing noise and enabling signal playback. The hardware incorporates an omnidirectional Electret Condenser Microphone, signal conditioning with AD620 and IC741, and a second-order bandpass filter for noise reduction. The Python-based software enables real-time signal recording, playback, and parameter computation. The heart sounds were acquired for 10 subjects using the fabricated chest piece. The recordings spanned a duration of one minute, and subsequently, sounds were played back, displaying both the waveform and the heart rate of the measured signal on the application screen, allowing for visual analysis. The heart rate obtained from our measurements was validated by cross-referencing it with the heart rate data derived from a patient monitoring system. Validation demonstrates accuracy comparable to clinical monitoring systems with a minimal acceptable variation. This standalone device holds great potential for healthcare, improving cardiac diagnostics' precision. Future work aims to integrate wireless capabilities, ensuring data security and ethical compliance.