Validation Studies for the Dual Optimization of Indentation Creep and Stress Relaxation of Biological Soft Tissues Using Biphasic Poroviscoelasticity: Potential Method for Brain Tissue

Abstract

Traumatic brain injury (TBI) is highly fatal and has profound physical and psychological repercussions for survivors. Knowledge of the precise material properties of brain tissue is crucial in developing holistic computational models to predict and prevent TBI. Despite the recent proliferation of material models of brain tissue, none have utilized porous media theory to explicitly include the significant fluid component of the hydrated soft tissue. Furthermore, the delicate composition of brain tissue limits the number of suitable biomechanical testing methodologies. In order to incorporate these considerations, in situ indentation creep and stress relaxation tests and linear biphasic poroviscoelasticity (BPVE) [1] were proposed to characterize the material properties of cerebral brain tissue. The objective of the present study was to evaluate these experimental and computational protocols in which the data from indentation creep and stress relaxation tests were simultaneously curve-fitted using a dual-optimization technique to determine the material parameters of the linear BPVE model.