Fig. 3
From: A new reservoir-based CPAP with low oxygen consumption: the Bag-CPAP
Oxygen delivery efficiency of the different devices to test. Oxygen delivery efficiency was assessed for noninvasive devices at two FiO2 target ranges corresponding to two clinical scenarios: 40–60% while the test lung simulated a moderate respiratory demand (panel A) and 80–100% while the test lung simulated a high respiratory demand (panel B), see methods section for more details. Oxygen flow rates were thus adjusted on each device according to manufacturer’s recommendations to reach those two FiO2 target ranges with the aim of delivering a PEEP level between 5 and 10 cm H2O. The areas shaded in orange represent the two FiO2 target ranges. The orange diamonds represent the value of the volume averaged FiO2 (i.e. the FiO2 actually delivered into the lungs in inspiration). The circles represent the oxygen delivery efficiency calculated as volume averaged FiO2/oxygen flow rate ratio; the greater this ratio, the more efficient the device is in terms of oxygen delivery and oxygen saving properties