graduate research assistant university of virginia
Abstract Text: Despite recent research, the mechanisms and pathology of blast brain injuries remains unclear. The finite element (FE) method is one potential tool used to address many of the biomechanics‐based questions related to blast brain injuries, particularly given the challenges related to experimental work in this field. FE models of animals may provide more insight into the mechanics and response of brain tissue because they can be matched with in vivo injury models to relate assessments made between biomechanists and neurologists to identify the tissue-level injury mechanisms and outcomes. This study developed and validated a FE model of a ferret head and brain for blast simulation. The response of the computational model was compared to in vivo shock-tube injury model, including the comparison between the spatial distribution of tissue-level metrics predicted in the FE model and the histopathology response of the animal model. In general, intracranial pressures were dependent on the peak pressure of the impinging blast wave, but strain responses in the brain were dependent on both peak pressure and duration of the incident blast wave. The strain response of the ferret brain model was better correlated with the injury outcome and histopathology of the in vivo injury models than the pressure response. In addition, strains in the blasted brain were an order‐of‐magnitude lower than those expected to produce blunt closed‐head TBI, but an order‐of‐magnitude higher in strain rate. The results suggest that the mechanism of neuropathology in blast brain injuries is high-rate strain response of neural tissue, and not high pressure as often hypothesized. Correlating the local mechanics of brain tissue with injury and severity is an important step to identify the mechanisms associated with blast neurotrauma. The mechanisms will be further realized with the ongoing enhancements to the FE ferret brain model to include axonal tractography and cerebrovasculature, and the work in development to collect ferret brain deformation data using controlled dynamic rotation.
Keywords: Blast-induced Traumatic Brain Injury, Ferret FE model, Injury Mechanisms
