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Characterizing cardiorespiratory interaction in preterm infants across sleep states using visibility graph analysis
Dandan Zhang1,2, Xi Long1,2, Lin Xu3
1Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Insights
Cardiorespiratory interaction (CRI) in preterm infants differs across sleep states and postmenstrual age (PMA). Quiet sleep shows stronger, more regular CRI, potentially aiding sleep state differentiation.
Area of Science:
- Neonatal Physiology
- Complex Systems Analysis
- Cardiorespiratory Dynamics
Background:
- Cardiorespiratory interaction (CRI) is well-studied in adults but under-investigated in preterm infants across various sleep states.
- Understanding CRI in preterm infants is crucial for assessing their physiological development and well-being.
- Previous research has not explored the nonlinear dynamics of CRI in different sleep states (wake, active sleep, quiet sleep) of preterm infants.
Purpose of the Study:
- To quantify and analyze cardiorespiratory interaction (CRI) in preterm infants during different sleep states.
- To investigate the influence of postmenstrual age (PMA) on CRI characteristics in preterm infants.
- To apply advanced nonlinear methods for a deeper understanding of CRI complexity in neonatal sleep.
Main Methods:
- Utilized the visibility graph (VG) method for nonlinear analysis of CRI in preterm infants.
- Extracted network parameters (mean degree, clustering coefficient, assortativity, complexity) from CRI data for each sleep state.
- Analyzed the interaction effects of sleep state and PMA on CRI parameters.
Main Results:
- Significant interaction effects between sleep state and PMA were observed for most CRI parameters.
- Sleep state significantly impacted CRI parameters, except for the clustering coefficient (CCm).
- Postmenstrual age (PMA) significantly influenced CRI parameters, except for complexity (D_SE).
- Quiet sleep (QS) exhibited more regular, stratified, and stronger CRI compared to active sleep (AS) and wake (W).
Conclusions:
- Cardiorespiratory interaction (CRI) in preterm infants is significantly associated with both sleep state and postmenstrual age (PMA).
- CRI demonstrates a more clustered pattern in preterm infants with higher PMA across sleep states.
- The distinct CRI patterns observed across sleep states, particularly in QS, suggest potential for using these parameters to differentiate sleep states in preterm infants.
Abstract:
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 (Dm) and its variability (Dsd), clustering coefficient (CCm) and its variability (CCsd), assortativity coefficient (AC), and complexity (DSE) 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 DSE. The main effect between sleep state and CRI parameters was statistically significant except for CCm, and that between PMA and CRI parameters was statistically significant except for DSE. 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.NEW & NOTEWORTHY 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.
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