Conf. on Modeling Simulation and Visualization MSV ′ 07 143 Computational Modeling of Br.pdf

Conf. on Modeling Simulation and Visualization | MSV ′07 | 143 Computational Modeling of Brain Dynamics during Repetitive Head Motions Igor Szczyrba School of Mathematical Sciences University of Northern Colorado Greeley, CO 80639, U.S.A. Martin Burtscher School of Electrical and Computer Engineering, Cornell University Ithaca, NY 14853, U.S.A. Rafal Szczyrba Funiosoft, LLC Silverthorne, CO 80498, U.S.A. Abstract We numerically model the effects of repetitive human head motions in traumatic scenarios that are as- sociated with severe brain injuries. Our results are based on the linear Kelvin-Voigt brain injury model, which treats the brain matter as a viscoelastic solid, and on our nonlinear generalization of that model, which emulates the gel-like character of the brain tissue. To properly compare the various traumatic scenarios, we use the BIC scale, which we developed to generalize the HIC scale to arbitrary head motions. Our simulations of the brain dynamics in sagittal and horizontal 2D cross-sections of the skull interior indicate that a repetitive reversal of traumatic head rotations can increase the severity/likelihood of brain injuries due to resonance effects. Keywords: brain injury modeling, resonance effects 1 Introduction A rapid head motion can result in a severe brain injury even if the skull remains intact. The origin of such Closed Head Injury (CHI) is attributed to the brain’s elasticity, which supports the propagation of shear waves. Experiments and mathematical models show that in traumatic situations, brain shear waves can create locally sufficiently high values of strain to cause either neuronal damage or vein rupturing. In particular, the three known analytic solutions1 of the linear Kelvin-Voigt (K-V) PDE system describing viscoelastic solids have been used to explain the mechanisms of brain hematomas [1] and to develop the Diffuse Axonal Injury (DAI) tolerance criterion. This criterion specifies characteristics of uni-directional, rapid head