Elastic Moduli of Lungs

Macroscopic elastic moduli governing the incremental deformation of pressurized lungs are calculated on the basis of a micromechanical study of an individual lung element (alveolus). The spongy lung tissue (parenchyma) is presumed to be in an initial state of isotropic tension, and the lung alveolus is idealized as a pin-jointed truss in the shape of a regular dodecahedron. The analysis is based on a variational statement of nonlinear structural mechanics, and the results show how the moduli depend on the initial tension and the assumed constitutive behavior of the idealized truss members.