A Wireless Digital Stethoscope Design

This paper presents a design and implementation of a digital stethoscope using a mobile device and wireless transmission. Our goal is to develop a smart digital stethoscope that adopts modern electronics and computing technologies to provide accurate information to assist cardiac auscultation. A signal conditioning circuit was designed to process an auscultation signal measured by a microphone. An Arduino processor board was used to convert the processed signal to a digital format. A Bluetooth module was employed to allow communication between the Arduino computer and an Android mobile phone. A mobile signal processing app was developed and implemented in Java. The current mobile app can store and retrieve uploaded heart sound signals for display; it also engages further analysis to identify the first and second heart sounds, and thus the systole and the diastole. The mobile app was implemented and validated using different clinical heart sound episodes.