Abstract :
Keywords Prematurity; Apnea of prematurity; Oxygen desaturation; Cardio-respiratory model; Oxygen model Highlights * Decay in oxygen saturation and heart rate depends on apnea length in premature infants * Cardiorespiratory models can successfully simulate apneas of premature infants * Chemoresponse is needed to simulate the decay in heart rate Abstract Apnea of prematurity (AOP) is a critical condition for preterm infants which can lead to several adverse outcomes. Despite its relevance, mechanisms underlying AOP are still unclear. In this work we aimed at improving the understanding of AOP and its physiologic responses by analyzing and comparing characteristics of real infant data and model-based simulations of AOP. We implemented an existing algorithm to extract apnea events originating from the central nervous system from a population of 26 premature infants (1248 h of data in total) and investigated oxygen saturation (SpO.sub.2) and heart rate (HR) of the infants around these events. We then extended a previously developed cardio-vascular model to include the lung mechanics and gas exchange. After simulating the steady state of a preterm infant, which successfully replicated results described in previous literature studies, the extended model was used to simulate apneas with different lengths caused by a stop in respiratory muscles. Apneas identified by the algorithm and simulated by the model showed several similarities, including a far deeper decrease in SpO.sub.2, with the minimum reached later in time, in case of longer apneas. Results also showed some differences, either due to how measures are performed in clinical practice in our neonatal intensive care unit (e.g. delayed detection of decline in SpO.sub.2 after apnea onset due to signal averaging) or to the limited number of very long apneas ([greater than or equal to]80 s) identified in our dataset. Abbreviations AOP, Apnea of prematurity; HR, Heart rate; CI, Chest impedance; SpO .sub.2, Oxygen saturation; CASEs, Central apnea-suspected event; CASE-D, Central apnea-suspected event followed by oxygen desaturation Author Affiliation: (a) Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands (b) Clinical Physics, Máxima Medical Center, Veldhoven, the Netherlands (c) Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands (d) Pediatrics, Máxima Medical Center, Veldhoven, the Netherlands * Corresponding author at: Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands. Article History: Received 3 June 2021; Revised 3 December 2021; Accepted 29 December 2021 Byline: Gabriele Varisco [g.varisco@tue.nl] (a,b,*), Irene Lensen (c), Deedee Kommers (a,d), Peter Andriessen (a,d), Peter Bovendeerd (c), Carola van Pul (a,b)