Developing new brain injury criteria for predicting the intracranial response by calculating von Mises stress, coup pressure and contrecoup pressure

Abstract

Animal and anatomic research has shown that head impact direction is an influential parameter in the risk of traumatic brain injury (TBI). In this field, however, not much research has been done on human subjects. The aim of this study is to assess influences of head impact direction on the intracranial responses. Furthermore, brain injury criteria have been developed to predict the influences of impact direction on probability of head injury and brain responses. For this purpose, 150 head impacts were simulated for three magnitudes and 50 directions of translational impact using finite element head model. Simulations were performed to evaluate pressure and stress responses by brain tissues due to changing the impact direction. Next, statistical analysis was used to develop new head injury criteria. The results indicate that TBI risk in simulations with sagittal and frontal planes are higher than those with transverse plane impacts. Furthermore, it has been shown that impact direction is as important as the impact magnitude and duration to develop head injury index. Moreover, new head injury indices have been proposed for predicting von Mises stress, coup pressure, and contrecoup pressure in the brain which have correlation coefficients 0.86, 0.92 and 0.89 with FEM responses, respectively. However, the results of this study show the influence of impact direction on TBI risk. It also indicates that impact direction and brain responses are necessary for developing head injury index.