Influence of bulk surfactant transport on airway reopening

During pulmonary airway reopening, a finger of air creates an interface that is continually expanding into a surfactant filled fluid. The quantity of surfactant transported to this interface affects the local surface tension, /spl gamma/, and thus the reopening pressure. The goal of this study is to demonstrate how transport barriers can affect the mechanics of this system. We use a combined boundary integral and finite difference technique to solve the governing equations in an axisymmetric geometry. When the quantity of surfactant in the fluid is low, a bulk diffusion barrier exists such that C/sub s//spl gamma//sub eq/, the equilibrium surface tension.