头高位倾斜实验心率变异性时频动态分析

Time-frequency analysis of heart rate variability during head up tilt

目的 研究心率变异性的动态时频分析 .方法 采用四种时频分析方法 ,包括短时傅立叶变换、Choi- William s分布、锥形核表示法与连续小波变换 ,分析头高位倾斜实验过程中的心率变异性信号 .结果 利用时频分析方法所得到的头高位倾斜实验中心率变异性变化趋势与用传统谱估计方法所得结果一致 ,倾斜开始后低频成份有所升高 ,高频成份降低 ;时频分析结果表明心率变异性谱成份在各个状态下均处于动态调节 .结论 利用时频分析方法可以观察心率变异性的动态变化 。

AIM To study the time frequency analysis of heart rate variability. METHODS Four time frequency methods were applied to heart rate variability analysis during head up tilt, which were short time Fourier transform, Choi Williams distribution, cone kernel representation and continuous wavelet transform. RESULTS Low frequency component increased while high frequency component decreased. Each component was under dynamic modulation during supine and head up tilt. CONCLUSION Time frequency methods can be applied to studying the dynamic change of heart rate variability, which could be potential in clinical monitoring.