Comparison of Actual Performance in the Flow and Fraction of Inspired O₂ among Different High-Flow Nasal Cannula Devices: A Bench Study

Table 2

The structure and mechanism differences among devices.

Devices	Air supply^a	Oxygen supply^b	Air-oxygen mixer^c	FiO2 monitor^d
AIRVO 2	Integrated turbines	Low-pressure oxygen supply from separated oxygen flowmeters	Manually adjusts oxygen flow to titrate the aimed FiO2 based on monitored or calculated FiO2 in real time	Ultrasonic oxygen analyzer
TNI softFlow 50				Not mentioned in public information
HUMID-BH
OH-70C		Wall supply	Proportional valves	FiO2 monitor provided
Bellavista 1000	Wall supply

Note: ^aAir supply may be responsible for flow accuracy. ^bOxygen supply would affect the FiO₂ accuracy. Flowmeters cannot provide enough oxygen flow when higher FiO₂ at high-flow levels is needed. ^cChanges in settings would alter the input air and oxygen flow or pressure, which will challenge the air-oxygen mixer and cause an inaccurate output. ^dThe FiO₂ monitor influences the FiO₂ accuracy.