Path length entropy analysis of diastolic heart sounds.
Early detection of coronary artery disease (CAD) using the acoustic approach, a noninvasive and cost-effective method, would greatly improve the outcome of CAD patients. To detect CAD, we analyze diastolic sounds for possible CAD murmurs. We observed diastolic sounds to exhibit 1/f structure and developed a new method, path length entropy (PLE) and a scaled version (SPLE), to characterize this structure to improve CAD detection. We compare SPLE results to Hurst exponent, Sample entropy and Multiscale entropy for distinguishing between normal and CAD patients. SPLE achieved a sensitivity-specificity of 80%-81%, the best of the tested methods. However, PLE and SPLE are not sufficient to prove nonlinearity, and evaluation using surrogate data suggests that our cardiovascular sound recordings do not contain significant nonlinear properties.
Department of Surgery, University of Medicine and Dentistry of New Jersey, Clinical Academic Building, 125 Patterson Street, New Brunswick, NJ 08901, USA. benjamin.griffel@gmail.com
Benjamin
B
Griffel
Mohammad K
MK
Zia
Vladamir
V
Fridman
Cesare
C
Saponieri
John L
JL
Semmlow
D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology*; D003971:Diastole; D019277:Entropy; D005260:Female; D006347:Heart Sounds; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted
1/f noise; Bioacoustics; Coronary artery disease; Diastolic murmurs; Entropy; Noninvasive measurements; Nonlinear signal processing