Due to various diseases that neonates face, the period from birth to the first 28 days is the most hazardous period of life [1, 2]. Globally, in 2017 alone, an estimated 6.3 million children died and nearly half (47%) of the under-five deaths occurred in the first month of life. Africa contributed to one-third of the world’s neonatal mortality burden [3, 4]. In the Sub-Saharan region, about 75% of deaths occur during the first week of life, and almost half occur within the first 24 hours [3, 5]. Preterm birth, birth asphyxia, and infections are the major causes of deaths . Among the mortality reasons, preterm birth complications, which contribute to more than one-third of the global neonatal mortality burden, are the leading cause for which a neonate has a higher risk of developing respiratory distress syndrome (RDS) [7–9].
Respiratory distress (RDS) is a cause of death for preterm newborns immediately following birth [7, 10–12]. It causes babies to need extra oxygen and help with breathing [3, 13]. RDS is often seen during the transition from fetal to neonatal life. The successful transition from fetal to neonatal life requires a series of rapid physiologic changes in the cardiorespiratory systems. These changes result in a redirection of gas exchange from the placenta to the lungs and require the replacement of alveolar fluid with air and the onset of regular breathing . Respiratory support is needed to treat RDS that begins immediately after birth to support immature lungs and to establish physiologic stability . These supportive methods are divided into invasive (mechanical ventilation, endotracheal intubation)  and non-invasive (various CPAP devices, non-invasive mandatory ventilation, non-invasive pressure ventilation) .
In low-income countries, invasive mechanical ventilation is often not available for children at risk of death from respiratory failure . However, continuous positive airway pressure (CPAP), which is one of the non-invasive methods, and also recommended by the World Health Organization (WHO) [12, 17], can improve survival in premature neonates with respiratory distress syndrome, especially for tertiary centers [9, 16, 18]. In developing nations, early use of CPAP along with early rescue surfactant (InSurE) is the best approach to managing the respiratory distress syndrome in preterm and extremely preterm infants . A delivery room with CPAP is feasible and minimizes the use of surfactants and mechanical ventilation by almost 50% .
But in higher income countries, in addition to using CPAP, advanced use of technology such as antenatal corticosteroids, exogenous surfactant therapy and mechanical ventilation have been used, and have significantly improved the survival of neonates with RDS . Despite the fact that no study was large, and both were conducted in academic medical centers, research results [20, 21] confirm that CPAP could improve survival beyond the neonatal period in children with primary pulmonary disease. However, the conventional CPAP devices and mechanical ventilation are expensive options, and mechanical ventilation requires high-level expertise and trained personnel, which is not currently affordable in many resource-limited countries [8, 10]. For instance, even if there are several conventional CPAP devices available, they cost up to US $6,000 to US $10,000 [22, 23], while a low-cost bubble nasal continuous positive airway pressure (bNCPAP) system may cost as low as US $350 to US $2000 [8, 24]. This means, comparatively, BNCPAP may cost approximately 15% of the cost of the cheapest mechanical ventilator .
Although the existing CPAP machine helps prevent the collapse of alveoli in the lungs and increasing survival rates with the CPAP machine, some babies still develop Bronchi pulmonary dysplasia (BPD), which is a serious lung condition that affects newborns that need oxygen therapy [22, 23, 25]. In addition to this, however, the main engineering design gap with the existing CPAP machine was that the condensate in the exhalation limb of the patient circuit during bubble CPAP can significantly increase the pressure delivered to the neonate. The back and forth movement of this condensate fluid causes oscillations in airway pressure that are much greater than the oscillations created by gas bubbling out of the exhalation tube into the water bath , and allows delivered pressures to reach pressures significantly higher than those intended. This can result in serious physical consequences such as air leaks, over distention, and gastric distention. Moreover, the accumulation of condensate in the expiratory limb of the bubble CPAP circuit increases the delivered pressure to the infant, which will cause additional resistive loading of the respiratory system, causing serious physiological complications (such as increased PaCO2, reduction in venous return, and compromised cardiac output) and potentially leading to respiratory failure by imposing large airway pressure oscillations that are out of phase with the neonate's intrinsic respiratory efforts [25, 26]. Since neonates are very sensitive, disconnecting the expiratory tube for cleaning will leave them at a higher risk. In addition to this engineering gap, there is still a lack of knowledge regarding factors influencing the implementation of the already existing CPAP machine in relatively limited settings . Due to this, developing countries need to address these preventable deaths by scaling up efforts to implement innovative and yet effective low-tech interventions to achieve the Sustainable Development Goals. The objective of this project was, therefore, to develop a bubble CPAP machine that has features to control the delivered continuous positive air pressure to keep it in a safe range at minimum cost. The developed BCPAP machine delivers safe therapy and monitors the continuous positive air pressure to protect the infants from the excessive pressure caused by the condensate accumulation in the expiratory limb of the circuit.