第二心音信号的瞬时功率和功率谱极大值分析

Instantaneous power maxima and power spectrum maxima analysis of second heart sounds signals

将时频分析方法用于第二心音的分析，研究了正常和异常第二心音信号的时频谱，根据时频分布的边缘条件，给出了第二心音的瞬时功率极大值和功率谱极大值特性，并将其作为描述心脏生理病理特性的量化指标。结果表明时频谱反映了第二心音各个成分在时频平面的能量分布及动态变化过程，瞬时功率极大值和功率谱极大值描述了第二心音信号的时变特征。

We employed the time-frequency analysis to the processing of the second heart sound signals and studiedthe time-frequency spectrum of the normal and abnormal second heart sound. According to the time marginal and frequencymarginal, we made the instantaneous power maxima and power spectrum maxima of the second heart sounds, which werethought as the quantity index about physiology and pathology. The results showed that the time-frequency spectrum of thesecond heart sounds gave a whole comprehensive description to dynamic course of the signals. The instantaneous power max-ima and power spectrun maximacontain the time varying information in the second heart sound.