Figure 5
From: Tidal Volume Estimation during Helmet Noninvasive Ventilation: an Experimental Feasibility Study
Bland-Altman plot of the differences between tidal volume measured by the turbine driven ventilator and the lung simulator at PEEP 8 cmH2O and different levels of leak flow. Data are reported in ml. LF: leak flow (values are expressed in liter per minute); TDV: Tidal volume (VT) measured by turbine driven ventilator; LS: Tidal volume (VT) measured by lung simulator. Average (x-axys): average of the two measurements; TDV – LS (y-axys): difference between mesurements. Bias: Average of the differences between measurements. 95% LoA: Limits of agreement (±1.96 standard deviation - SD - of the bias). In this plot, the overall bias is 29 ml, and 95% LoA are from 19 to 38 ml. The difference between VT measured by the TDV and the LS remains of no clinical relevance among all simulated leak flows.
