提出了分频段相位随机化替代数据方法,与噪声滴定法相结合,观察了不同频率成分对心搏混沌的影响.结果显示心率变异性高频成分相位随机化的替代数据使混沌强度显著降低,提示谱分析的频率成分中蕴含着信号的非线性特性.提出的方法能有效分析不同频率成分对非线性的贡献,该法不仅适用于心率变异性还适用于其他确定性信号的特性分析.
We proposed a new hybrid method combining the band-phase-randomized surrogate data with noise titration to discern the influence of spectral components on heartbeat chaos. The results demonstrate that the chaotic strength of phase-randomized surrogate data in the high frequency band (HF) of heart rate variability (HRV) is reduced significantly, which indicates that the frequency components of spectral analysis involve intrinsic chaotic information. The hybrid method proposed in this study is effective to distinguish the different contributions of spectral components to chaotic strength of the test data. This method is applicable not only to HRV but also to other deterministic signals.