Computer modelling has shown that brain injury may occur within a millisecond after someone's head hits the windscreen in a car accident. Paul Taylor of Sandia National Laboratory and Corey Ford, neurologist at the University of New Mexico's Department of Neurology and MIND Imaging Centre, made the discovery after modelling early-time wave interactions in the human head following impact with a windscreen, one scenario for traumatic brain injury (TBI).
TBI means that the brain can lose its ability to perform cognitive and memory tasks, process information, and perform a variety of motor and coordination functions. One aim of the research is to explain why people with head injuries of similar severity often have very different reactions.
Modelling brain injury is a more humane way to study scenarios leading to TBI than the traditional trial-and-error approach using laboratory animals. The two researchers imported a computed tomography (CT) scan of a healthy female head into the shock-physics computer program developed by Sandia. Computer models were then constructed representing the skull, brain, CSF, and windscreen glass. The simulations were run on Sandia's Thunderbird parallel computer using 64 processors for each simulation.
The model represents what would happen to an unrestrained person hitting the windscreen of an car in a 34 mph head-on collision with a stationary barrier. In discussions between Taylor and Ford, it became apparent that different types of cell damage might occur depending on the type of stress to which the cells are exposed.
‘Through our modelling we were able to predict early-time stress focusing within the brain during an impact event’ says Taylor. 'However, we have yet to identify what specific levels of stress will lead to TBI. This is the focus of our future research effort.' The models could also be used to develop better protection devices such as headgear for sports and military personnel.