Characterizing white matter tissue in large strain via asymmetric indentation and inverse finite element modeling.

摘要: Characterizing the mechanical properties of white matter is important to understand and model brain development injury. With embedded aligned axonal fibers, typically modeled as a transversely isotropic material. However, most studies characterize tissue using models with single anisotropic invariant or in small-strain regime. In this study, we combined experimental procedure - asymmetric indentation inverse finite element (FE) modeling estimate nearly incompressible material parameters matter. A minimal form comprising three was employed simulate responses large-strain The were estimated global optimization based on genetic algorithm (GA). Experimental data from two configurations porcine matter, parallel perpendicular fiber direction, utilized parameters. Results study confirmed strong anisotropy large strain. Further, our results suggested that both are needed sufficient accuracy, indenter-sample friction important. Finally, also showed consistent those previously obtained via trial-and-error forward FE method These findings useful parameterization especially under deformation, demonstrate potential proposed technique other soft biological tissues properties.