Low-Resource Oxygen Blender for Use in Modified Bubble CPAP Circuits

Continuous positive airway pressure (CPAP) is a method of respiratory support used around the world to treat children with lower respiratory tract infections (LRTI) [1]. Bubble continuous positive airway pressure (bCPAP) is an effective form of CPAP that is currently used in both high and low-resource countries. Low cost, modified bCPAP devices have been designed as an ideal form of CPAP in low-resource areas [2]. However, patients in low-resource settings undergoing bCPAP treatment are often given pure oxygen, which has been linked to retinopathy in neonates and cardiovascular complications [3]. This problem is typically avoided by using commercial oxygen blenders which can titrate down the concentration of oxygen delivered, however these blenders can cost nearly 1000 USD and are almost always unavailable in low-resource settings. The fact that there are no low-cost oxygen blenders compatible with bCPAP available prevents low-resource hospitals from being able to provide blended oxygen to patients. There is a need for a low-cost oxygen blender for use in low-resource settings. We propose a passive oxygen blender that operates via entrainment of atmospheric air. The device can easily be assembled in low-resource areas using a 22 gauge hypodermic needle, two 3cc syringes, tape or super glue, and materials required for bCPAP - for approximately 1.40 USD per device. The blender can achieve oxygen concentrations as low as 60% with bCPAP levels of 5cm H2O (490 Pa).