A Biphasic Hyperelastic Model for Analysis of Fluid Transport in Brain Tissue

Poroelastic or biphasic models have been used to study hydrocephalus [1] and the fluid transport that occurs during positive pressure infusion, also called convection enhanced delivery [2,3]. Each of the studies is limited by the assumption of linear elasticity of the solid phase. Nonlinear stress-strain curves under finite deformations have been documented for brain tissue under tension [4] and compression [5]. The nonlinear variation of hydraulic conductivity with strain has also recently been taken into account [1,3] and this effect has been deemed to play an important role in both the mechanics of the tissue and the associated fluid transport.