Portable, Neonatal, Continuous Positive Airway Pressure Device for Low-Resource Settings

Abstract

An estimated 9 million infants are born prematurely each year in south Asia and sub-Saharan Africa, and the leading cause of death in preterms is respiratory distress syndrome (RDS). Continuous positive airway pressure (CPAP) is a popular treatment for RDS and has been proven to be safe, feasible, and effective for use in low- and middle-income countries (LMICs). The well-documented success of supportive CPAP in LMICs and prophylactic CPAP in developed countries indicates that delivery room CPAP has the potential to be implemented successfully in LMICs. The aim of this thesis is to explore the feasibility of a simple, low-cost, portable neonatal CPAP device for use in the delivery room in LMICs. A portable CPAP device was modelled in Simulink to predict the pressure and flowrate at any point in the CPAP circuit. A prototype composed of a centrifugal fan, silicone tubing, nasal cannula, and a PEEP valve was constructed. The prototype was tested using a Dräger Infant Test Lung to simulate a breathing neonate. The model predicted that neonates with higher peak inspiratory flows risked rebreathing exhaled gas. When compared to the experimental data, it was determined that the model underestimated resistance in the circuit and overestimated the mean pressure delivered to the patient. The prototype effectively delivered a positive pressure to the simulated patient; however, the pressure was not consistent across all experimental conditions. Cannula type, amount of leak, and breathing pattern all impacted the treatment delivered. The Simulink model can be used as a tool to aid in design decisions, but is not highly accurate, and thus does not eliminate the need for practical experimentation. The prototype was a good proof-of-concept and should be investigated further in consultation with clinicians.