H. Sava et al., APPLICATION OF THE MATCHING PURSUIT METHOD FOR STRUCTURAL DECOMPOSITION AND AVERAGING OF PHONOCARDIOGRAPHIC SIGNALS, Medical & biological engineering & computing, 36(3), 1998, pp. 302-308
The paper evaluates the performance of an automatic adaptive time-freq
uency method to detect each cardiac cycle of a phonocardiogram (PCG) a
nd extract average heart sounds and PCG cycles. The proposed method co
mbines a global search of the PCG, in terms of the energy distribution
of the most important components, with a local search relating to the
specific events found within a cardiac cycle. The method is applied t
o 100 PCG recordings from 50 patients with an aortic bioprosthetic val
ve. The performance of the proposed method is compared with a commonly
used semi-automatic method that is based on the combined analysis of
an electrocardiogram (ECG) and the PCG signal. Results show that the p
roposed method clearly outperforms the semiautomatic method, especiall
y in the case of patients with malfunctioning bioprostheses. By elimin
ating the need to record an ECG as the time-reference signal, this met
hod reduces hardware overheads when analysis of PCG signals is the pri
mary aim. It is also independent of subjective human judgment for sele
ction of reference templates and threshold levels. Furthermore, the me
thod is robust to artefacts, background noise and other kinds of signa
l interferences. With minor modifications, the procedure described cou
ld be applied to other types of biomedical signal in order to extract
coherent transient components and identify specific events.