关键词: 体位;心率;时频分析

    摘 要: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-Williams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，可将其应用于临床监测.

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

    WANG Shou-Yan，ZHANG Li-Fan，CHENG Jiu-Hua，WANG Xing-Bang

    Department of Physiology，Faculty of Aerospace Medicine，Fourth Military Medical University，Xi'an710033，China

    Keywords:posture;heart rate;time-frequency analysis

    Abstract: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 contin-uous wavelet transform.RESULTS Low frequency compo-nent 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 ......