Wang S, Zhang L, Zheng J
Department of Aerospace Physiology, The Fourth Military Medical University, Xi'an.
Space Med Med Eng (Beijing). 1997 Aug;10(4):263-7.
In order to study the nonstationary heart rate variability (HRV) signals under gravitational stress, a time-variant autoregressive spectral estimation method has been implemented, which made it possible to study dynamically the process of cardiac autonomic regulation during various gravitational stresses. The HRV signals obtained from 8 subjects during seated-LBNP testing before and after a six-month aerobic training were analyzed by the implemented algorithm. The obtained time-variant spectra might clearly reveal the time course of changes of decrease in HFn and increase in LF/HF, reflecting the time course of cardiac vagal withdrawal and indices with time during seated-LBNP were increased in most of the subjects. In brief, our work shows that the method of time-variant AR spectrum analysis for non-stationary HRV signals makes it possible to elucidate the dynamics of cardiac autonomic regulatory activity under gravitational stress and to detect the subtle changes in HRV after aerobic training.
为了研究重力应激下的非平稳心率变异性（HRV）信号，已实施了一种时变自回归谱估计方法，这使得动态研究各种重力应激期间心脏自主调节过程成为可能。通过该算法分析了8名受试者在为期六个月的有氧训练前后进行坐姿下体负压试验期间获得的HRV信号。获得的时变谱可能清楚地揭示高频功率（HFn）降低和低频/高频（LF/HF）增加的变化时间进程，反映了心脏迷走神经活动减弱的时间进程，并且在大多数受试者中，坐姿下体负压期间的这些指标随时间增加。简而言之，我们的工作表明，用于非平稳HRV信号的时变自回归谱分析方法能够阐明重力应激下心脏自主调节活动的动态变化，并检测有氧训练后HRV的细微变化。
