The mechanics of lung tissue under high-frequency ventilation (Q2706100)

The paper describes the use of homogenization theory to predict the macroscopic behaviour of lung tissue based on the three-dimensional microstructure of respiratory regions, under the simplifying assumption that the microstructure is periodic. The equations for macroscopic air flow, pressure, and tissue deformation are derived, and the parameters are determined from a specification of tissue microstructure and its material properties. For isotropic tissue, the parameters determining the macroscopic tissue response can be estimated from bulk measurements. Using these parameter estimates, the authors obtain solutions in one dimension. The significant difference is observed in solution behaviour when the alveolar wall obeys the structural damping hypothesis (dependence of lung tissue shear viscosity on the frequency of forcing).