Akuisisi, Pengolahan, dan Analisis Isyarat Suara Jantung (Heart Sound Signal Acquisition, Processing, and Analysis).

Different physicians may hear the same heart sound differently, and perhaps interpret them differently. The aim of this research is to realize a system that can aid the physicians to interpret objectively the heart sounds by analyzing the heart sound signals in time, spectral, and wavelet domain. The research was realized by constructing an acquisition circuit that amplifi and filter the signal detected by a stethoscope coupled with a microphone. The amplified signal is then digitalized and processed by computer besides amplifying its power to drive a loudspeaker. The processed signal is then analyzed using time, frequency, and wavelet techniques. The results show that the acquisition circuit can amplifi and filter the signal with the pass-band gain of 90 dB with a cut-of ffrequency of about 1 KHz and a transition-band slope of â40 dB/decade. The heart sounds interval and heart beat rate of the sample persons can be measured. The spectral bandwidth of the signal can be estimated and the time âfrequency pattern of the signal can be observed. Keywords: Heart sound, acquisition, processing, spectral, wavelet, analysi