Computational Study on the Bridging Vein Rupture of Blast-Induced Traumatic Brain Injury Using a Numerical Human Head Model

The occurrence of blast-induced traumatic brain injury (bTBI) in people serving in battle environments is dramatically high. The blast front, or leading edge of the shock wave is a brief, acute overpressure wave that travels supersonically with a magnitude that is several times higher than that of ambient. The shock wave propagates through the human head and injures intracranial tissues. Classical neuropathologic signs of bTBI include cerebral contusion, diffuse axonal injury, subdural hematoma (SDH) and subarachnoid hematoma, of which subdural hematoma is the most dominating sign of bTBI. Here, computational finite element (FE) modeling is used to investigate the mechanical process of bTBI. The overall goal of the present study is to find the injury threshold of the SDH injury due to bTBI, by investigating the biomechanical response of the bridging veins in the human brain under shock wave loading that originates from detonation. This research mainly develops a basic FE human head model which consists of skull and parts of the brain. The geometric models of skull and brain are developed from segmentations of magnetic resonance imaging (MRI) files of a real human head. The boundary conditions on the neck and head are modeled as a displacement-fixed condition. The numerically simulated blast waves are applied on the human head model as external loading conditions. The internal response in the subarachnoid space is used as loadings on the bridging vein submodel. The maximum principal stress of the bridging vein is used to determine the whether there is failure of the bridging vein, thus estimating the “injury threshold” of SDH in bTBI. Results show that 150g TNT blast of 1 meter away from the head can result in a high possibility of SDH occurrence.