心率变异信号的多尺度分析

Multiscale Analysis of Heart Rate Variability Signal

心率变异信号(HRV)综合反映了脑神经、中枢神经和呼吸等生理活动,包含了大量自主神经系统功能的重要信息,即便没有确定扰动的影响,HRV信号仍具有高度不平稳性,存在非线性动力学特征,对于临床上心脏活动状态评估和疾病诊断有着重要意义。然而,目前对HRV信号的非线性动力学研究主要采用单一维度和尺度的分析方法,很难完全表征HRV信号对应的非线性生理机制。本文以健康人和心脏病人为研究对象,分别利用尺度相关Lyapunov指数(SDLE)和多尺度多重分形分析(MSMF)刻画HRV信号的多尺度混沌特性和分形特性两个方面的非线性动力学特征。结果发现,HRV信号是一个动力学过程,心脏病人HRV信号的混沌特性指数比健康人的高,分形特性指数比健康人的低,表明健康人的心脏对内外环境刺激有更强的适应性和可变性,而且利用多尺度分析比单一分析更加准确。该研究对于进一步解析HRV信号非线性特性的生理学意义有着促进作用。

Heart rate variability signal(HRV)reflects the physiological activities of the brain,central nervous system and respiration,including a large number of important functions of the autonomic nervous system function,even if there is no determination of the impact of disturbance,HRV signal is still highly uneven,there is non-linear Dynamic characteristics,for the clinical assessment of cardiac status and disease diagnosis is of great significance.However,the nonlinear dynamics research of HRV signals is mainly based on a single dimension and scale analysis method,it is difficult to fully characterize the nonlinear physiological mechanism of HRV signal.In this paper,we use the scale-dependent Lyapunov exponent(SDLE)and multiscale multifractal analysis(MSMF)to characterize the non-linear dynamics of HRV signal's multiscale chaotic and fractal properties.It was found that the HRV signal was a dynamic process.The chaotic characteristic index of HRV signal was stronger than that of healthy people,the fractal characteristic index was weeker than that of healthy people,which indicated that the heart of healthy people had better adaptability to internal and external environmental stimuli and variability,and the use of multi-scale analysis is more accurate than a single analysis.This study has a positive effect on further analysis of the physiological significance of HRV signal's nonlinearity.