健康人心率变异性中的不稳定周期轨道

THE UNSTABLE PERIODIC ORBITS EMBEDDED IN HEART VARIABILITY OF HEALTHY SUBJECTS

为刻划心脏节律存在的确定性动力学特征 ,运用不稳定周期轨道分析方法对健康青年人的RR间期时间序列数据进行分析。研究结果揭示健康人心脏节律中存在显著的不稳定周期轨道及不稳定周期轨道分级(周期1 ,周期2 ,周期3 ,周期4)现象 ,表明健康青年人心脏节律的动力学特性中包含着显著的确定性行为。通过跟踪不稳定周期轨道随时间的演变 ,亦表明心脏节律的变化中存在着固有的非平稳性。

To characterize the deterministic dynamics in heart rhythm, the unstable periodic orbit analysis were the RR interval time series of healthy young men. The unstable periodic orbits (UPO) with statistical significance and the hierarchies of UPOs(period 1, period 2, period 3 and period 4) have been extracted from the heart rhythm. It suggests that in healthy young men, the dynamics of normal heart rhythm contains significant deterministic components. Furthermore, the inherent non-stationary of the heart rhythm can be shown by developing of period 1 orbit. The results provide further evidences to verify that chaos dynamics exists in heart rate variability.