Year: 2026
Type: article
Abstract: The acoustic cardiography method is popular in medical practice; the method is simple, non-invasive and relatively cheap, though the accuracy of obtained results appears to depend strongly on the distortions of the vibroacoustic field occurring near transducer location due to mechanical properties (small stiffness) of the biotissues, which results in methodological errors. The aim of the work was to investigate the methodological error occurring in the recording of heart sounds registration by an accelerometer and an electronic stethoscope. The investigations were performed in the frequency range from 20 to 1000Hz corresponding to the main spectrum of heart sounds. Cases of recording kinematic characteristics of chest surface vibrations using an accelerometer placed directly on the body surface or secured with an elastic strap, as well as recording dynamic characteristics when using an electronic stethoscope, were studied. A variant of the electronic stethoscope was analysed in two versions: with and without a short sound tube. To describe the interaction between the transducer and biological tissues, a viscoelastic layer model was used, taking into account the mechanical impedance of the “biotissue – sensor” system. Analytical expressions were obtained for estimating the relative methodological error as a function of signal frequency and transducer parameters. The numerical estimates of the methodological error of heart sounds registration at different frequencies with regard to parameters of transducers are given. Calculation of the expressions obtained shows that reducing the mass of the sensor reduces the error. Using an elastic fastening strap increases the error due to additional damping of tissue vibrations. For an electronic stethoscope the error proved to depend on the volume of the stethoscope head cavity and the presence of a short sound tube, which changes the frequency characteristics of the system up to causing the resonance effects. The results obtained can be useful for optimizing the sensor design and improving the accuracy of heart sound recording methods.
Institution: Lviv Polytechnic National University
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7220698680