心率变异性短时分析的非平稳性影响研究

针对短时心率变异性(heart ratev ariability,HRV)分析在临床中常常不能得到一致性结果的情况,研究几种常用HRV短时分析参数受非平稳性的影响。通过几种参数与平稳性衡量参数(均值、标准差)的相关性分析,结果表明,各短时参数在长时数据中呈现出随时间变化的波动,其中HFnorm和SE受非平稳干扰影响大,LFnorm和BE受非平稳干扰影响小。从而推论,非平稳干扰是影响短时HRV分析结果一致性的一个原因,尽量排除非平稳干扰,严格保证数据的可比性前提,可提高其分析结果的可靠性和一致性;同时,HRV中的低频波动不只包含了非平稳干扰的影响,还蕴含了心脏动力系统的固有特性,短时分析参数由于未能包含这部分低频信息,所以不能对心脏动力系统提供全面描述,这是导致短时HRV分析结果一致性差的另一个重要原因。

The Effects of Non-Stationary on Short Term Analysis of Heart Rate Variability

In short-term analysis of Heart Rate Variability （HRV）, it is hard to get the consistent results. In order to explain this phenomenon, the non-stationary interference on analysis parameters of short-term HRV has been studied. In virtue of correlation analysis, the results showed that although all the four parameters （HFnorm, LFnorm, SE, BE） considered fluctuate with the lapse of time, only some of them （HFnorm and SE） correlate significantly with non-stationary. Therefore, on the one hand, the consistence of short-term analysis of HRV is impacted by non-stationary interference, and the equal environmental impacts are prerequisite in collecting HRV data from different subjects to make them comparable. On the other hand, the low frequency fluctuations of HRV contain not only the non-stationary interference, but also the intrinsic cardiac dynamic characteristics. Thus, short-term analysis methods, which discard absolutely the low frequency components, can not reveal the all-sided information of HRV. This is the inherent shortage of short-term HRV analysis methods, which contributes to the results inconsistence.