Hyper-viscoelastic modeling of brain tissues based on the Ogden model

Constitutive modeling serves as a crucial tool for understanding and predicting the behavior of human brain tissue in both healthy and diseased states. This process necessitates the formulation of precise constitutive laws and the integration of ample experimental data to accurately correlate tissue deformation with stress. In this work, we present a phenomenological hyper-viscoelastic model based on the Ogden model that effectively differentiates between elastic and viscous stress responses, enhancing the precision in capturing the mechanical behavior of brain tissue. This includes aspects such as nonlinear response, rate dependence, and tensile–compressive asymmetry. We have validated our model using experimental data from porcine, monkey, and human brain tissues under a variety of loading conditions, thereby confirming its accuracy and reliability. Furthermore, we have undertaken comprehensive review and analysis of experimental conditions in the existing studies on porcine brain tissue, aiming to standardize data selection. The model demonstrates its ability to accurately predict the mechanical behavior across different human brain regions under varied loading scenarios with minimal adjustments. This significant progress promises to aid in the development of medical diagnostic tools and enhance research into brain functionality and injury mechanisms.