Strain energy descriptions of biological swelling. II: Multiple fluid compartment models

A series of multicompartmental, biphasic elastic tissue models is developed. In its most general form, the models consist of multiple tubular networks, each with an internal spring network. In addition, another spring network occupies the extratubular compartment. Strain energy functions are derived for the models, as well as expressions for the fluid pressures in each compartment arising from volume expansion or swelling. Calculations also show that the distribution of fluid among compartments is a significant determinant of tissue elasticity.