Fig. 2

A A representative stress–strain loading profile of an airway tissue where the stress and strain transitions were calculated by determining the intersection of the initial and final modulus slopes from a bilinear fit of the low- and high-strain portions of the curve. Maximum stress was defined as the stress value at 60% strain with a strain rate of 1%/s. B A representative cyclic loading cycle utilized to measure tissue hysteresis and calculate energy loss. C A representative viscoelastic hold used to calculate the stress relaxation with a loading strain rate of 5%/s