Compliance (c) Static compliance measured in absence of flow o C=AV/AP= 1/E where e=elastance, V=volume, P=pressure =AV/(Pairspace-Ppleura) Pleura esophageal total=AV/(Pairspace-Patmospheric) total chest wall Etotal= Elmg Chest wall COPD, asthma 3100 normal Pulm Fibrosis. fibrothorax Pressure C=ΔV/ΔP = 1/E where E=elastance,V=volume, P=pressure  Clung = ΔV/(Pairspace –Ppleura), Ppleura = Pesophageal  Ctotal = ΔV/(Pairspace-Patmospheric)  . Ctotal Clung Cchest wall 1 1 1   Etotal  Elung  Echest wall % Predicted Volume Pressure 100 0 normal COPD, asthma Pulm. Fibrosis, fibrothorax Static compliance measured in absence of flow