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

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