Summary of studies evaluating oxygen delivery devices using a high-fidelity human simulator with smoke particles of <1 µm (an aerosol of solid particles). The smoke was illuminated by a laser light-sheet and high-definition video was used to measure dispersion distance away from the manikin. Indicated dispersion distances give an idea of proximity of contaminated bio-aerosols, to which healthcare workers may be directly exposed. HFNC: high-flow nasal cannula;F_IO2：吸入氧比例。