Figure 2.

Model predictions for Protocol 1 (left column), and Protocol 2 with either $g_1=0.1$ (middle column) or $g_1=0.01$ (right column). (a–c) Airway radius normalized with respect to the initial radius plotted as a function of time for the length of the whole protocol. Dashed lines indicate agonist level or amplitude of transmural pressure oscillations (right axes), gray curve shows results of application of static transmural pressure, and black curves show results from application of transmural pressure oscillations. On this timescale the oscillations in normalized radius appear as solid black regions (low $k_1$ in (a) and high $\text{Δ}{P}_{TM}$ in (b)). (d–f) Airway radius as a percentage of baseline radius, (g–i) wall thickness as a percentage of baseline wall thickness, and (j–i) strain amplitude as a percentage of baseline radius. The radius and thickness are taken at the end of the final oscillation when $P_{TM}=P_{TM0}$. Dashed lines for Protocol 1 (d, g, and j) show results for static transmural pressures $\left(\text{Δ}{P}_{TM}=0\right)$, whereas the solid lines show results for transmural pressure oscillations. B and C in (e, f, h, i, k, and l) refer respectively to the baseline (initially prestressed) state and contracted state (i.e., after application of agonist). The stars and error bars indicate the experimental findings of LaPrad et al. (15); only dynamic results are shown in (d, g, and j). To see this figure in color, go online.