Abstract

Two major difficulties of analyzing the dynamics of biologic variables are their nonstationarity and nonlinearity.  Several approaches other than conventional Fourier-based analysis, such as reassignment method, wavelet analysis and Hilbert-Huang Transform (HHT), are proposed in biomedical research to improve the analysis of the time-frequency representations of the biosignals to better assess the time-varying nature of physiological systems.  Among those methods, HHT is suggested as an adaptive data analysis (data-driven) method to study trend and instantaneous frequency of nonlinear and non-stationary data and attracts more attentions recently in biological and medical areas. In this presentation, several clinical applications of HHT in probing the alterations of underlying physiological mechanisms during aging and pathological conditions will be introduced and discussed.