Based On Information Theory, Heart Rate Rr Sequence Of Phase Space Reconstruction Study

The cardiac RR Intervals Series is one of the important heart condition performances. The heart movement is a process of information variatonal, each heart wrestles can consume the partial information of the previous heart wrestles. Therefore it is meaningful that applying the information theory method to research the cardiac RR intervals Series.This paper introduces several methods of delay time and embedding dimension for phase space reconstruction of RR time series. According to the information theory, we use equal-probability symbolic analysis method to compute mutual information, and the delay time is established by the rule of minimum mutual information. Furthermore, we use an information theory approach to determine embedding dimension, which is conditional entropy method. We conduct simulation experiments respectively using the Lorenz system, and show that this approach is reasonable.The Cardiac RR Intervals Series were used as experimental data, which were collected from the young (21-34 yr) and elderly (68-81 yr) groups of healthy subjects. We compute the delay time and Approximate Entropy of every Cardiac RR Intervals Serie respectively. The results indicate that, the delay times of old persons are obviously longer than the time of the younger (p<0.015) by t-test. The delay time and Approximate Entropy of Cardiac RR Intervals Series are negative correlative by analysising, which shows that delay time reflects complexity of Cardiac RR Intervals Series, and its value is negative correlative with HRV's activity and Cardiovas-cular's complexity. Through the phase space reconstruction of RR time series, we know the attractors of RR series is strange attractors, which shows that RR series are neither random signals nor simple periodic signals but chaos.