Linxia Gu, associate professor of mechanical and materials engineering, is lead author in a study that examines how improvised explosive devices impact blood vessel networks and can lead to traumatic brain injury. (Photo credit: University of Nebraska-Lincoln)
Blast waves from improvised explosive devices (IEDs) that are placed throughout combat zones in the Middle East may strain on the brain more greatly than previously thought, researchers suggest in a new study published in the online journal Computational and Mathematical Models in Medicine.
Lead author Linxia Gu, associate professor of mechanical and materials engineering at the University of Nebraska-Lincoln (UNL), and her team authored the study to examine how blood vessel networks affect the potential incidence of traumatic brain injury (TBI) from these IEDs, according to a release from the university.
The release explains that the team simulated the force of the IEDs by using a “shock tube” to propel 900-mile-per-hour blasts of air at two models of the human head—one featuring blood vessels, the other without.
The model embedded with blood vessels suffered almost three times as much principal strain and more than six times as much shear strain in the brain stem than the model without the blood vessels. As well, its corpus callosum, which facilitates communication between the left and right hemispheres of the brain, experienced almost twice the principal strain and nearly 2.5 times the shear strain of the model without the embedded blood vessels, the release continues.
The study also showed that both types of strain rose in tandem with the density and diameter of blood vessels, per the release.
“If it turns out that these blood vessel networks really are having such a big impact, then maybe we’ve been underestimating the strains caused by blast waves,” Gu says in the release.
Since blood vessels are much stiffer than brain tissue, Gu and her team initially thought that they might reinforce the brain against blast waves in the same way that steel rebar strengthens concrete, per the release.
“This might be true for a lower-frequency blast loading, but under high-frequency loading, it’s not,” Gu explains in the release. “We think the interface between the vessel network and brain tissue contributes to the increased strains. It really seems to make a big difference.”
The study was conducted through UNL’s Trauma Mechanics Research Initiative, which according to the release houses a range of experiments aimed at better understanding and protecting against TBI.
Gu believes that findings from her study and others could help improve the design of helmets worn by military forces worldwide.
“If we understand how these blood vessel networks impact brain dynamics, maybe we can design (headgear) differently to optimize its protection,” Gu says in the release. “No helmet can protect equally against every type of force. Current helmets protect well against bullets and shrapnel, but they don’t protect as well against blasts.
“To improve the design of a helmet, we need to know why this damage occurs. That’s the ultimate goal,” Gu concludes.
[Source(s): University of Nebraska-Lincoln, EurekAlert]
