THE TIME DELAY OF AIR/OXYGEN MIXTURE DELIVERY AFTER THE CHANGE OF SET FIO2: AN IMPROVEMENT OF A NEONATAL MATHEMATICAL MODEL
Leoš Tejkl; Jakub Ráfl; Petr Kudrna
Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
Vyšlo v časopise:
Lékař a technika - Clinician and Technology No. 3, 2019, 49, 77-82
Oxygen therapy is an essential treatment of premature infants suffering from hypoxemia. Normoxemia is maintained by an adjustment of the fraction of oxygen (FiO2) in the inhaled gas mixture that is set manually or automatically based on peripheral oxygen saturation (SpO2). Automatic closed-loop systems could be more successful in controlling SpO2 than traditional manual approaches. Computer models of neonatal oxygen transport have been developed as a tool for design, validation, and comparison of the automatic control algorithms. The aim of this study was to investigate and implement the time delay of oxygen delivery after a change of set FiO2 during noninvasive ventilation support to enhance an available mathematical model of neonatal oxygen transport. The time delay of oxygen delivery after the change of FiO2 during the noninvasive nasal Continuous Positive Airway Pressure (nCPAP) ventilation support and during the High Flow High Humidity Nasal Cannula (HFHHNC) ventilation support was experimentally measured using an electromechanical gas blender and a physical model of neonatal lungs. Results show the overall time delay of the change in the oxygen fraction can be divided into the baseline of delay, with a typical time delay 5.5 s for nCPAP and 6.5 s for HFHHNC s, and an exponential rising phase with a time constant about 2–3 s. A delay subsystem was implemented into the mathematical model for a more realistic performance when simulating closed-loop control of oxygenation.
computer model – oxygen support – neonatal oxygen transport – Respiratory system – time delay
Polin R, Fox WW. Fetal and neonatal physiology. Philadelphia: Saunders, 1992. ISBN 0-7216-3514-8.
Tin W, Gupta S. Optimum oxygen therapy in preterm babies. Arch Dis Child Fetal Neonatal Ed. 2007;92(2):F143-F147. DOI: 10.1136/adc.2005.092726
Hasan A. Understanding mechanical ventilation: A practical handbook. 2nd ed. New York: Springer, 2010. ISBN 978-184-8828-681.
Hagadorn JI, Furey AM, Nghiem TH, Schmid CH, Phelps DL, Cole CH. Achieved versus intended pulse oximeter saturation in infants born less than 28 weeks' gestation: The AVIOx study. Pediatrics. 2006;118(4):1574-1582. DOI: 10.1542/peds.2005-0413
Clarke A, Yeomans E, Elsayed K, Medhurst. A randomised crossover trial of clinical algorithm for oxygen saturation targeting in preterm infants with frequent desaturation episodes. Neonatology. 2015;107(2):130-136. DOI: 10.1159/000368295
Mitra S, Singh B, El-Naggar W, McMillan DD. Automated versus manual control of inspired oxygen to target oxygen saturation in preterm infants: A systematic review and meta-analysis. J Perinatol. 2018;38(4):351-360. DOI: 10.1038/s41372-017-0037-z
Morozoff EP, Saif M. Oxygen therapy control of neonates: Part II – Evaluating manual, PID and fuzzy logic controller designs. Control Intell Syst. 2008;36(3):238-249.
Claure N, Gerhardt T, Everett R, Musante G, Herrera C, Bancalari E. Closed-loop controlled inspired oxygen concen-tration for mechanically ventilated very low birth weight infants with frequent episodes of hypoxemia. Pediatrics. 2001;107(5): 1120-1124. DOI: 10.1542/peds.107.5.1120
Morozoff EP, Saif M. Oxygen Therapy Control of Neonates – Part I: A Model of Neonatal Oxygen Transport. Control Intell Syst. 2008;36(3):227-237.
Morozoff EP. Modelling and fuzzy logic control of neonatal oxygen therapy [master’s thesis]. Burnaby: Simon Fraser University, Department of Engineering Science; 1996.
Krone B. Modelling and control of arterial oxygen saturation in premature infants [master’s thesis]. Columbia: University of Missouri; 2011.
Fathabadi OS, Gale TJ, Lim K, Salmon P, Dawson JA, Wheeler KI, Olivier JC, Dargaville PA. Characterisation of the oxy-genation response to inspired oxygen adjustments in preterm infants. Neonatology. 2015;109(1):37-43. DOI: 10.1159/000440642