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. 2022 Jun 27:15:187-197.
doi: 10.2147/MDER.S318218. eCollection 2022.

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

Patricia S Coffey  1 , Alec Wollen  1
Affiliations

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

Patricia S Coffey et al. Med Devices (Auckl). .

Abstract

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.

Keywords: affordability; biomedical engineering; global health; hyperoxia; medical device design; noninvasive ventilation; preterm infants; respiratory distress syndrome.

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Conflict of interest statement

Both authors have been active in developing the bCPAP and blenders technology while employed at PATH. PATH and/or the authors do not hold any relevant financial or nonfinancial relationships related to this product. The authors report no other conflicts of interest in this work.

Figures

Figure 1
Figure 1
Bubble continuous positive airway pressure (bCPAP) assembly diagram. Contents: 1) bubbler stand, 2) cannula adapter, 3) air-oxygen blenders (37% and 60%), 4) nasal cannula, 5) bubbler straw, 6) bubbler bottle, 7) bubbler bottle lid. Circuit tubing: 8) cannula adapter to straw (140 cm), 9) cannula adapter to blender (50 cm), 10) blender to oxygen (130 cm).
Figure 2
Figure 2
Oxygen blenders included in PATH bCPAP device. (A) PATH’s fixed-rate bCPAP blenders. (B) Blender principle of operation.
Figure 3
Figure 3
Respiratory circuit with test lung.
Figure 4
Figure 4
Blender verification test setup.
Figure 5
Figure 5
Sound measurement test setup.
Figure 6
Figure 6
Blender FiO2 for high/low flow and pressure (n=45).
Figure 7
Figure 7
Difference in average flow before and after conditioning (LPM).
Figure 8
Figure 8
Difference in average FiO2 before and after conditioning (% oxygen).
Figure 9
Figure 9
PATH CPAP average sound levels 50 cm away from blender.
See this image and copyright information in PMC

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