Nonclinical Bench Performance Testing of a Very Low-Cost Nonelectric Bubble Continuous Positive Airway Pressure (bCPAP) and Blenders Device Designed for Newborn Respiratory Support.

Purpose: Bubble continuous positive airway pressure (bCPAP) is often used to treat respiratory distress experienced by some 15 million preterm infants born globally every year. In low- and middle-income countries, improvised bCPAP devices are used, often without a blender that protects the infant from the sequelae of excessive oxygen exposure.

Materials and methods: The aim of this bench testing was to assess the mechanical safety and performance of the PATH bCPAP and blenders device, which provides a stable and reliable source of pressurized blended gas without the requirement for a source of compressed medical air or electricity. The device includes two fixed ratio blenders: a "low" blend that provides 37% oxygen and a "high" blend that provides 60% oxygen. We performed bench testing to characterize the performance of the bCPAP and blenders, including respiratory circuit verification, blender verification, conditioned humidity testing, and sound measurement.

Results: Test results for all performance variables met the acceptance criteria of our product requirement specification. The device provides a fixed ratio of air and oxygen that is consistent over the entire range of clinically relevant pressures (4 to 8 cmH₂O) and remains consistent despite changes in flow (2 to 7 liters per minute). The blend is stable within ± 5% of the blenders' nominal blend ratio when used with a 100% oxygen source, irrespective of the flow and pressure from the oxygen source or the flow and pressure of the blended gas delivered to the neonate. Sound and humidity test results were within specifications.

Conclusion: This very low-cost nonelectric bCPAP and blenders device is optimally designed to deliver a stable and reliable source of pressurized blended gas.