Fig. 3
A Average ± standard deviation stress–strain loading profiles of untreated, collagenase treated, and elastase treated porcine airway specimens for all lung regions shown in both axial and circumferential stretch directions. The untreated tracheal region exhibited the highest stresses while the small and large bronchi shared similar stress–strain profiles. In the large deformation region (strains > 0.3), enzymatic treatments tended to result in decreased stress values for all lung regions and directions compared to untreated counterparts