The primary outcome, the (transpulmonary) ΔP level, is analyzed using a repeated measures ANOVA. The effect mediation of ventilator parameters on the (transpulmonary) ΔP is analyzed by mediation analysis. P-values of 0.05 are used for statistical significance. When appropriate, statistical uncertainty will be expressed by the 95% confidence levels. All statistical analysis will be performed with the R language and environment for statistical computing.