Fig. 3

Bland–Altman plots showing estimation error versus true ΔP across the cohort of 90 virtual adult ARDS patients, with \({P}_{high}\)= 30 cmH₂O and \({P}_{low}\) = 5 cmH₂O. Solid lines indicate the average deviation (‘Bias’) between the true and estimated value of ΔP, dashed lines indicate the limits of agreement (LOA, the distribution of values within ± 1.96 standard deviation from the mean) A ΔP estimated by switching to volume controlled ventilation (as described in [2]), assuming that the monitoring PEEP recorded is exactly equal to the actual total expiratory pressure. B ΔP estimated using Eqs. (6) and (7), under the assumption that flow, volume and pressure decay mono-exponentially, as proposed in [7]. C ΔP estimated using Eqs. (4) and (5) as proposed in [6], under the assumption that the time taken to achieve full expiration and eliminate PEEP_i (i.e., achieve zero expiratory flow) is equal to 4 expiratory time constants \(\tau .\) D ΔP estimated as in C but under the assumption that the time taken to eliminate PEEP_i is equal to 3 expiratory time constants \(\tau\)