Traumatic Brain Injury and Helmet Design
AP/Petr David Josek
According to Iraq and Afghanistan Veterans of America, from 10 to 20 percent of Iraq war vets, or between 150,000 and 300,000 soldiers, have suffered a traumatic brain injury. TBI does not necessarily leave a visible wound; rather, the force of an explosion can bruise the brain, causing a variety of symptoms than may be difficult to distinguish from other psychological injuries prevalent in combat zones. Developing better ways to diagnose and treat TBI is important, but preventing it in the first place would be even better.
Recent research from scientists at Lawrence Livermore National Laboratory investigates the mechanics of how blasts affect the brain and may provide an answer. Traditionally, armor design, including helmets, focused on minimizing the force of impacts–either from objects striking the soldier or from the soldier being thrown against hard surfaces. But the new study investigates how shock waves from explosions can flex and deform the skull itself, creating internal pressure on the soft brain tissue. Some current helmet designs that maintain a gap between the skull and the helmet wall actually amplify the pressure from blast waves. The research could lead to improved helmet design that protects from projectiles, impacts, and blast waves.
The abstract from “Skull Flexure from Blast Waves: A New Mechanism for Brain Injury with Implications for Helmet Design”:
Traumatic brain injury [TBI] has become the signature injury of current military conflicts. The debilitating effects of TBI on society are long-lasting and costly. Although the mechanisms by which impacts cause TBI have been well researched, the mechanisms by which blasts cause TBI are not understood. Various mechanisms, including impacts caused by the blast, have been investigated, but blast-induced deformation of the skull has been neglected. Through the use of hydrodynamical numerical simulations, we have discovered that non-lethal blasts can induce sufficient flexure of the skull to generate potentially damaging loads in the brain, even if no impact occurs. This mechanism has implications for the diagnosis of TBI in soldiers and the design of protective equipment such as helmets.
(Hat tip: VSL: Science)
Comments on this article