Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Philips Research, Eindhoven, The Netherlands.
J Appl Physiol (1985). 2021 Apr 1;130(4):1015-1024. doi: 10.1152/japplphysiol.00333.2020. Epub 2021 Feb 4.
Cardiorespiratory interaction (CRI) has been intensively studied in adult sleep, yet not in preterm infants, in particular across different sleep states including wake (W), active sleep (AS), and quiet sleep (QS). The aim of this study was to quantify the interaction between cardiac and respiratory activities in different sleep states of preterm infants. The postmenstrual age (PMA) of preterm infants was also taken into consideration. The CRI during sleep was analyzed using a visibility graph (VG) method, enabling the nonlinear analysis of CRI in a complex network. For each sleep state, parameters quantifying various aspects of the CRI characteristics from constructed VG network including mean degree () and its variability (), clustering coefficient (CC) and its variability (CC), assortativity coefficient (AC), and complexity () were extracted from the CRI networks. The interaction effect of sleep state and PMA was found to be statistically significant on all CRI parameters except for AC and . The main effect between sleep state and CRI parameters was statistically significant except for CC, and that between PMA and CRI parameters was statistically significant except for . In conclusion, the CRI of preterm infants is associated with sleep states and PMA in general. For preterm infants with a larger PMA, CRI has a more clustered pattern during different sleep states, where QS shows a more regular, stratified, and stronger CRI than other states. In the future, these parameters can be potentially used to separate sleep states in preterm infants. The interaction between cardiac and respiratory activities is investigated in preterm infant sleep using an advanced nonlinear method (visibility graph) and some important characteristics are shown to be significantly different across sleep states, which has not been studied before.
心肺交互作用（CRI）在成人睡眠中得到了深入研究，但在早产儿中，特别是在不同的睡眠状态（包括觉醒（W）、活跃睡眠（AS）和安静睡眠（QS））中，尚未进行研究。本研究旨在量化早产儿不同睡眠状态中心肺活动的相互作用。还考虑了早产儿的胎龄（PMA）。使用可视性图（VG）方法分析睡眠期间的 CRI，从而能够在复杂网络中对 CRI 的非线性进行分析。对于每个睡眠状态，从构建的 VG 网络中提取量化 CRI 特征的各种参数，包括平均度（）及其变异性（）、聚类系数（CC）及其变异性（CC）、配价系数（AC）和复杂性（）。睡眠状态和 PMA 的交互作用对除 AC 和 之外的所有 CRI 参数均具有统计学意义。睡眠状态与 CRI 参数之间的主要作用除 CC 外具有统计学意义，而 PMA 与 CRI 参数之间的主要作用除 外具有统计学意义。总之，早产儿的 CRI 一般与睡眠状态和 PMA 有关。对于具有较大 PMA 的早产儿，CRI 在不同睡眠状态下具有更聚类的模式，其中 QS 比其他状态表现出更规则、分层和更强的 CRI。将来，这些参数可用于分离早产儿的睡眠状态。使用先进的非线性方法（可视性图）研究早产儿睡眠中心肺活动的相互作用，并显示出一些重要特征在睡眠状态之间存在显著差异，这在以前的研究中尚未进行过研究。
