A Nonlinear Biphasic Model for Mass Transport During Constant Flow-Rate Infusion Into Brain Tissue

摘要

Convection-enhanced delivery is a means to deliver therapeutic agents directly into brain tissue. Biphasic models have been used to study the concomitant fluid and mass transport that occurs during infusion, however previous studies have been limited by the assumption of linear elasticity of the solid phase [1]. In contrast, nonlinear stress-strain curves have been documented for brain tissue under finite deformation in tension and compression [2, 3].rnRecently, we proposed a spherical, biphasic model for constant flow-rate infusions that considers nonlinear stress-strain curves under finite deformation and nonlinear variation of hydraulic conductivity with deformation [4]. With this model, we demonstrated that the tissue deformation and the resulting convective fluid velocity show significant differences relative to the previous linear models. In this study, we determine the effect of geometric and material nonlinearities on the transport and distribution of the infused therapeutic agent.