Comparison of Linear and Nonlinear Models for Estimating Brain Deformation Using Finite Element Method

This paper presents finite element Computation for brain deformation during craniotomy. The results are used to illustrate the comparison between two mechanical models: linear solid-mechanic model, and non linear finite element model. To this end, we use a test sphere as a model of the brain, tetrahedral finite element mesh, two models that describe the material property of the brain tissue, and function optimization that optimizes the model's parameters by minimizing distance between the resulting deformation and the assumed deformation. Linear and nonlinear model assumes finite and large deformation of the brain after opening the skull respectively. By using the accuracy of the optimization process we conclude that the accuracy of nonlinear model is higher but its execution time is six time of the linear model.