Wu Ming-Chya, Hu Chin-Kun
Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 May;73(5 Pt 1):051917. doi: 10.1103/PhysRevE.73.051917. Epub 2006 May 24.
We use the empirical mode decomposition method to decompose experimental respiratory signals into a set of intrinsic mode functions (IMFs), and consider one of these IMFs as a respiratory rhythm. We then use the Hilbert spectral analysis to calculate the instantaneous phase of the IMF. Heartbeat data are finally incorporated to construct the cardiorespiratory synchrogram, which is a visual tool for inspecting synchronization. We perform analysis on 20 data sets collected by the Harvard medical school from ten young (21-34 years old) and ten elderly (68-81 years old) rigorously screened healthy subjects. Our results support the existence of cardiorespiratory synchronization. We also investigate the origin of the cardiorespiratory synchronization by addressing the problem of correlations between regularities of respiratory and cardiac signals. Our analysis shows that regularity of respiratory signals plays a dominant role in the cardiorespiratory synchronization.
我们使用经验模态分解方法将实验性呼吸信号分解为一组固有模态函数（IMF），并将其中一个IMF视为呼吸节律。然后，我们使用希尔伯特谱分析来计算该IMF的瞬时相位。最后纳入心跳数据以构建心肺同步图，这是一种用于检查同步性的可视化工具。我们对哈佛医学院从十名年轻（21 - 34岁）和十名老年（68 - 81岁）经过严格筛选的健康受试者收集的20个数据集进行了分析。我们的结果支持心肺同步的存在。我们还通过解决呼吸和心脏信号规律性之间的相关性问题来研究心肺同步的起源。我们的分析表明，呼吸信号的规律性在心肺同步中起主导作用。
