Heart sound analysis based on autoregressive power spectral density

This paper presents a new spectral analysis method of heart sound (HS) by using autoregressive power spectral density (AR-PSD) for discriminating normal and abnormal HS. Digital stethoscope was used to collect HS and transmitted into computer by USB interface, so as to store, display and analysis. Practical cases of normal/abnormal HS analysis are demonstrated to validate the usefulness and efficiency of the proposed method. In order to improve diagnosis accuracy and see the result more clearly, characteristic parameters were defined by the intervals between the crossed points of AR-PSD envelope curve and Threshold value(THV) line. From the scatter graph of 20 normal and 20 abnormal HS, their characteristic parameters distributed in different obvious areas, it provides a new idea for heart sound quantized analysis.