Characterization of biological internal dynamics by the synchronization of coupled chaotic system

We investigate an characterization method of biological internal dynamics which is extracted the observable biological signals. For the measured time series of the pulsation of human finger's capillary vessels, we reconstruct an internal dynamics with a form of vector field by using embedding method. In order to characterize and recognize such internal dynamic structure, we construct an artificial mimic dynamics of them in the digital computer. We characterize the similarity of internal dynamics of a target time series and previously measured series by the synchronized response of their mimic and target when we coupled them. In this paper, we show three types of coupled system and the effect of coupling is analyzed by the cross-correlation of coupled system.