A three-dimensional porcine brain model was developed to investigate the similarities/differences between porcine and human head models on impact response.

Three two-dimensional porcine brain finite element models were then developed to simulate the animal tests. It was found that to produce a realistic shear stress response of the brain, differentiation between the gray and white matter and the ventricles should be made. High shear stress/strain locations predicted by the models corresponded well with DAI (diffuse axonal injury) sites found in the test, which suggested that shear stresses/strain could be the cause of DAI and could be used to predict DAI.

A three-dimensional human head model has been developed to study the influence of the gray and white matter as well as ventricles on brain impact response, the causation of DAI and SDH (subdural hematoma). A frontal and a sagittal plane rotational impact were simulated. Simulation results confirmed the findings of the two-dimensional porcine model. Only an inhomogeneous brain model can reproduce shear stress concentrations at boundaries between the gray and white matter, and around ventricles induced by impacts. The impact response of the bridging veins was found to be reasonable and consistent with experimental findings. Tension in the bridging veins induced by the rebound of the brain in a frontal impact can be an important mechanism for SDH. The importance of impact direction in causing SDH was confirmed by simulation results.

A side impact motor vehicle accident reconstruction was attempted using EDSMAC, the MADYMO model and the new human head model.

This study leads to a new concept for brain injury modeling. For the first time, the brain is modeled as an inhomogeneous structure of the gray and white matter with the ventricles inside, and with the parasagittal bridging veins included, in a three-dimensional human brain finite element model.