胎儿心率时间序列的非线性混沌特性分析

根据胎儿心率（Fetal heart rate, FHR）信号属于短数据量时间序列的特点, 利用替代数据方法, 并结合判断混沌特性的特征量关联维、 最大李氏指数和复杂度对FHR信号进行分析. 结果表明, 两组FHR信号与依据两种零假设所产生的替代数据差别较大, FHR信号具有非线性成分, 由混沌特征量的判据S＞2可知, FHR信号具有非线性混沌特性. 

Analysis on Non-linear Chaos Characteristic of Fetal Heart Rate Time Series

Signal change of fetal heart rate is reflected by the function of the circulatory system and the central nervous system. Understanding the dynamics behavior of fetal heart rate is a kind of simple method to infer the situation of fetus in the uterus. According to the characteristic of FHR signal belonging to the short data time series, the FHR signal was analyzed by means of the surrogate data method combined with correlation dimension, the largest Lyapunov exponent and complexity which can identify chaotic features. The research indicates that there are remarkable discriminations between the FHR signal and the surrogate data produced by two groups of two kinds of null hypotheses respectively, indicating that the FHR signal has the nonlinear components and chaos characteristic quantity criterion S＞2, which explains that the FHR signal has nonlinear chaos characteristic.