Digital stethoscope system – the feasibility of cardiac auscultation

The application of the digital stethoscope system is a new tendency in methods of cardiac auscultation. Heart sounds,
generated by the fluctuations of blood velocity and vibrations of muscle structure, are an important signal in the primary
diagnosis of heart diseases. Since the XIXs century for physical examination an analog stethoscope was used, but the
development of microelectronics enable the construction of digital stethoscopes which started modern phonocardiography.
The typical hardware of the system could be divided into analog and digital parts, respectively. The first one consists of
microphone and pre-amplifier. The second one contains a microcontroller with peripherals for data saving and
transmission. Usually the specialized software is applied for the signal acquisition and digital signal processing (filtering,
spectral analysis and others).
This paper presents an overview of methods used in cardiac auscultation and expected developing path in the future. It also contains the description of our digital stethoscope system, which is planned to be used in poliphysiographical
studies.