With their “digital head” a team of mechanical engineers is perfecting a computer model that could have profound implications—from the battlefield to the playing field.
Knocked Out. Bell Rung. Punch Drunk. Shell Shocked. Seeing Stars. The lexicon of concussion is long and colorful, but creative as these twists of phrase are, they mask a much darker truth: Head trauma is no laughing matter.
In the best cases, a short wait, a few smelling salts, and things are back to normal. In more serious cases, the resulting dizziness, moodiness, headaches, and confusion can haunt the victim for life. In the most extreme cases, repeated concussion can be fatal.
Deciphering the difference between these extremes has been a challenge for medical science. Concussion cannot be photographed or measured by conventional medical imaging—MRI, CT, PET scans, and the like—and so it remains a largely invisible menace. Doctors are left with an arcane series of cognitive tests to determine whether an injury has occurred and, if so, how bad the damage is. It is a problem that has become, quite literally, a matter of life and death.
Into this void have stepped K.T. Ramesh, the Alonzo G. Decker Jr. Professor in Science and Engineering, and a team of mechanical engineers who have begun to apply their specialized knowledge of extreme materials to better understand traumatic brain injury. Ramesh, a professor of mechanical engineering and director of the Hopkins Extreme Materials Institute (HEMI), has developed an advanced computer model that uses real-world data to recreate the physiological and biomechanical dynamics of brain injuries. His goal is to combine real-time, in-game data from sensors mounted in helmets and mouth guards to help assess brain injuries as they happen.
“We call our model the digital head, and believe it will address some of the big challenges of studying brain injury. The biggest is ethical in nature because you can’t do injury-causing experiments on living people, so the digital head gives us insights that just aren’t available in other ways,” explains Nitin Daphalapurkar, an assistant research professor at HEMI, collaborating with Ramesh on the project.
Though computer models to study brain injury are not new, Ramesh and Daphalapurkar have incorporated several novel factors in their model that help them not only understand what is happening to the cellular and subcellular structures of the brain but also pinpoint where damage has occurred and what sort of cognitive impairments—blurred vision, memory loss, dizziness, and so forth—might result from any specific injury.
Jell-o With a Twist
Ramesh has approached the matter as a true engineer, as a study of a complex biomechanical material. The brain is hyperelastic. In texture, it is not unlike Jell-O. Tap it, shake it, push it, pull it, the brain will move about, stretching, straining, and deforming but eventually returning to its resting state.
When the head is subjected to a rapid and powerful force or change of direction, like that from an aggressive hit in football, a car accident, or the explosion of a bomb, the brain quite literally sloshes around within the rigid confines of the skull, compressing and stretching, twisting and turning until the energy of the blow dissipates. These motions are at the core of traumatic brain injury.