Visco-hyperelastic characterization of human brain white matter micro-level constituents in different strain rates.
In this study, we propose a computational characterization technique for obtaining the material properties of axons and extracellular matrix (ECM) in human brain white matter. To account for the dynamic behavior of the brain tissue, data from time-dependent relaxation tests of human brain white matter in different strain rates are extracted and formulated by a visco-hyperelastic constitutive model consisting of the Ogden hyperelastic model and the Prony series expansion. Through micromechanical finite element simulation, a derivative-free optimization framework designed to minimize the difference between the numerical and experimental data is used to identify the material properties of the axons and ECM. The Prony series expansion parameters of axons and ECM are found to be highly affected by the Prony series expansion coefficients of the brain white matter. The optimal parameters of axons and ECM are verified through micromechanical simulation by comparing the averaged numerical response with that of the experimental data. Moreover, the initial shear modulus and the reduced shear modulus of the axons are found for different strain rates of 0.0001, 0.01, and 1 s-1. Consequently, first- and second-order regressions are used to find relations for the prediction of the shear modulus at the intermediate strain rates. Graphical Abstract The applied procedure for characterization of brain white matter micro-level constituents. The macro-level experimental data in different strain rates are used in the context of simulation-based optimization to obtain the properties of axons and extracellular matrix material.
['Ramzanpour|Mohammadreza|M|', 'Hosseini-Farid|Mohammad|M|', 'McLean|Jayse|J|', 'Ziejewski|Mariusz|M|', 'Karami|Ghodrat|G|']
D000818:Animals D001369:Axons D001696:Biomechanical Phenomena D001698:Biomedical Engineering D000070642:Brain Injuries, Traumatic D003198:Computer Simulation D004548:Elasticity D005109:Extracellular Matrix D020342:Finite Element Analysis D006801:Humans D008959:Models, Neurological D013314:Stress, Mechanical D014783:Viscosity D066127:White Matter
Visco-hyperelastic Strain rate Micromechanical simulation Simulation-based optimization