Fig. 1
From: Influence of different noninvasive oxygenation support devices on tidal volume
Effect of each device on tidal volume and mouth pressure–time product in bench model. A and C Represent the effect of each device on tidal volume (A) and mouth pressure–time product (C) according to the simulated respiratory effort. A low respiratory effort denotes an inspiratory muscle pressure of 5 cmH2O; a moderate respiratory effort denotes an inspiratory muscle pressure of 10 cmH2O; a distress denotes an inspiratory muscle pressure of 20 cmH2O combined with an expiratory muscle pressure of 10 cmH2O. Panels B and D represent the effect of each device on tidal volume (B) and mouth pressure–time product (D) according to the respiratory mechanics. p < 0.001 for both overall comparisons on one-way ANOVA. * denotes p < 0.05 vs. O2-mask within each respiratory effort and respiratory mechanics. HFNC: high-flow oxygen through nasal cannula; CPAP: continuous positive airway pressure; NIV: noninvasive ventilation