Circuit Lake

Electronic Project and Circuit Collection

AVR Digital Stethoscope

02/11/2013 Category: AVR, Data Acquisition, Detector, Measurement, Microcontroller

This digital stethoscope can be used as computer aided diagnosis (CAD) applications for the detection of cardiac murmurs. It can assist physicians in analyzing cardiac signals in real time during auscultation to reduce the risks of not detecting heart murmurs conditions.

The Stethoscope system is built based on ATmega644 AVR microcontroller and custom-built sensor to capture heart sounds at 8 kHz. After processed by MCU, the captured signals are outputted via pulse-width modulation to a standard 3.5 mm audio socket for real-time auscultation. To record and playback audio waveforms, it is equipped with 1MB external Flash memory chip.

Digital Stethoscope Project

This portable auscultation device uses 20×4 wide LCD display and a 16-button keypad for user interface. User can also use MATLAB interface to visualize real-time and recorded data via USART for better analysis. The MATLAB uses transmitted data to calculate and display the patient’s average heart rate in beats per minute. This useful project is built by Michael Wu & Garen Der-Khachadourian.