Nonlinear dynamics analysis of electrical signal time series evoked by acupuncture

Different kinds of the acupuncture methods to the Zu'san'li point can evoke various electrical signal time series, and nonlinear dynamics method is used to analyse them. We reconstruct the phase space attractor and get the time delay through calculating mutual information function. And the Cao's method is used to determine the optimal embedding dimension. The time series are considered chaotic by plotting the attractor, qualitatively. The largest Lyapunov exponents (LLE) are computed based on the Takers' embedding theorem. The LLEs of the time series are positive. Finally the difference among various acupuncture methods is discussed.