Lab Report: Modeling the Impact of Brain Damage
By Janelle Weaver ’99
Hundreds of thousands of people experience traumatic brain injuries (TBIs) each year due to sports or recreational activities in the United States alone. Even one blow to the head may cause temporary confusion or extended memory loss and depression.
Thayer assistant professor Songbai Ji is collaborating with Thayer adjunct associate professor Richard Greenwald and Dartmouth Medical School psychiatry professor Thomas McAllister to learn more about such injuries. The researchers equipped college and high school football and hockey players with helmets embedded with sensors—made by Greenwald’s company, Simbex—that measure head acceleration. McAllister administered neuropsychiatric tests and brain imaging scans to players before the season, after they experience concussions, and at the end of the season. Ji generated a model linking biomechanical data about head impacts in athletes to assessments of their brain damage.
By estimating tissue strain and stress responses in different brain regions, the model can predict the likelihood and severity of injury following a concussion. Ji’s subject-specific model produced more accurate results than a model that simply uses average head dimensions for males. Ultimately, Ji hopes to characterize the patterns of brain damage caused by distinct types of impacts, such as hitting a hard or soft surface. “This information will be useful because it will help us better design helmets and understand under what type of impact conditions there could be a higher risk of head injury in what regions,” he says.
—Janelle Weaver is a freelance writer based in Colorado.