Integrated Curriculum for Anthroposophic Medicine, University of Witten/Herdecke, Witten, Germany Institute of Integrative Medicine, University of Witten/Herdecke, Witten, Germany
Integrated Curriculum for Anthroposophic Medicine, University of Witten/Herdecke, Witten, Germany Institute of Integrative Medicine, University of Witten/Herdecke, Witten, Germany.
Philos Trans A Math Phys Eng Sci. 2015 Feb 13;373(2034). doi: 10.1098/rsta.2014.0087.
The analysis of symbolic dynamics applied to physiological time series retrieves dynamical properties of the underlying regulation which are robust against the symbolic transformation. In this study, three different transformations to produce a symbolic series were applied to fetal RR interval series to test whether they reflect individual changes of fetal heart rate variability in the course of pregnancy. Each transformation was applied to 215 heartbeat datasets obtained from 11 fetuses during the second and the third trimester of pregnancy (at least 10 datasets per fetus, median 17). In the symbolic series, the occurrence of symbolic sequences of length 3 was categorized according to the amount of variations in the sequence: no variation of the symbols, one variation, two variations. Linear regression with respect to gestational age showed that the individual course during pregnancy performed best using a binary transformation reflecting whether the RR interval differences are below or above a threshold. The median goodness of fit of the individual regression lines was 0.73 and also the variability among the individual slopes was low. Other transformations to symbolic dynamics performed worse but were still able to reflect the individual progress of fetal cardiovascular regulation.
应用符号动力学分析从生理时间序列中提取出潜在调节的动力学特性，这些特性对符号转换具有鲁棒性。在这项研究中，将三种不同的转换应用于胎儿 RR 间隔序列，以测试它们是否反映了胎儿心率变异性在妊娠过程中的个体变化。每种转换都应用于从 11 名胎儿在妊娠第二和第三个三个月获得的 215 个心跳数据集（每个胎儿至少 10 个数据集，中位数为 17）。在符号序列中，根据序列中符号变化的数量对长度为 3 的符号序列的出现进行分类：符号没有变化、有一个变化、有两个变化。关于胎龄的线性回归表明，使用反映 RR 间隔差异是否低于或高于阈值的二进制转换来执行个体妊娠期间的表现最佳。个体回归线的中位数拟合优度为 0.73，个体斜率之间的变异性也较低。其他符号动力学转换表现较差，但仍能够反映胎儿心血管调节的个体进展。
