The embedded digital stethoscope uses the adaptive noise cancellation filter and the type I Chebyshev IIR bandpass filter to reduce the noise of the heart sound

Abstract

In this paper, we propose a design and implementation of an embedded digital stethoscope that uses the adaptive noise cancellation filter and the Type I Chebyshev IIR bandpass filter to reduce the noise of the heart sound. We integrate a traditional stethoscope, two microphones, an amplifier, an analog to digital conversion, a DSP board, and embedded board. First, the system acquits the heart sound, amplify, digitize, and input into the DSP board for noise reduction by using of the adaptive noise cancellation and the IIR bandpass filter. Then, the preprocessed heart sound signals are send into the embedded board for the LCD displaying and the interface to PC. Overall, we design the digital filter, interface circuit, displaying driver, graphical user interface. The prototype system integration of the hardware and software modules shows the stable operation with a range of adjustments.