Powerful explosive devices of 21st century warfare prompt urgent calls to re-engineer protective gear

Battle-inflicted head injuries are as old as war itself, evidenced by the copper helmets worn by Bronze Age soldiers to deflect blows from spears and axes. Over the ensuing millennia, as weapons evolved, so did armor. Today, the powerful explosive devices of 21st century warfare have once again raised the stakes, prompting urgent calls to re-engineer protective gear.

With two major grants from the U.S. Department of Defense, NJIT will help meet this challenge by investigating the effects of shock waves on the brain in order to design and test helmets that can withstand the penetrating blasts from weapons such as improvised explosive devices (IEDs).

"We want to protect people and save lives. These weapons have changed the landscape of war, and we are working on new paradigms of protection and health," said Namas Chandra, director of NJIT's Center for Injury Biomechanics, Materials and Medicine and the principal investigator for two recent grants from the military totaling nearly $4.5 million.

Studies from recent conflicts indicate that 20 percent of the U.S. deployed force suffers from traumatic brain injury (TBI), and that in Afghanistan and Iraq, about two-thirds of military personnel with TBI were wearing protective equipment when they were hurt. Helmets designed to protect against bullets and other impacts are unproven against shock waves from IEDs, NJIT researchers say.

Indeed, scientists and engineers still do not understand what physical component of the IED blast induces TBI or the delayed, secondary biochemical damage at the cellular level. Researchers at the Center will determine these mechanisms of injury while also shedding light on the capabilities of protective devices such as helmets, body armor and eye goggles under blast-loading conditions. Their goal is to develop specifications that would guide the development of new personal protection systems for soldiers.

In the university's blast simulation lab, Chandra and his team are examining the connection between the strength, distance, speed and positioning of a blast and the type and degree of injury it causes. They are also assessing the physical damage to both the structure of cells and their capabilities, including the ability to transmit signals.

To study these impacts, researchers release compressed gases such as helium to create air shocks that race down an enclosed "shock tube" at speeds of up to 1,300 miles an hour toward a helmet outfitted with pressure gauges. Over the course of the project, they will test different types of helmets in the chamber as well as live biological tissues to explore the actual mechanisms of injuries.

The biomedical engineers at the Center are collaborating with biologists, neuroscientists, clinicians, and computer modelers at NJIT and other institutions to establish metrics that will allow field doctors to determine if a soldier has sustained a brain injury, exactly where in the brain it occurred and its degree of severity, from mild concussion to serious TBI. These collaborations are expanding the Center's scope to encompass biology, engineering and medical research.

"The DoD medical research community has asked for guidance on building combat helmets to? protect against blast-related brain injury, but we can't give it until we understand the injury mechanisms," said Michael Leggieri, director of the DOD's Blast Injury Research Program, during a recent visit to NJIT. "Understanding the underlying mechanisms of blast-related brain injury is a critically important problem that we've been after for years, but have yet to solve."

Blast injury is a complex problem "that cannot be solved by a single community - not by engineering, life sciences or biomedical engineering alone. These communities must work together," Leggieri added, calling NJIT's Center "a necessary collaboration to solve a difficult blast-injury problem."

Chandra has added several students to the team as well, noting, "We're not just here to solve a problem, but to train the next generation of researchers, as understanding how to maintain brain health will take time." Matthew Kuriakose, a Ph.D. student in the third year of a biomedical engineering program, said he joined the team for the chance to contribute to what he called "a fresh field" with a compelling mission.

"Soldiers are being injured in ways we don't even know about and I feel that those of us with relevant expertise should help them in any way we can," Kuriakose said, adding, "There haven't been many thorough field-relevant experiments that accurately measure the impact on the brain of high-pressure blast waves."

Atam Dhawan, NJIT's vice provost for research, said he expected the project to also shed light on brain injuries sustained outside of military conflicts.

"Traumatic brain injuries occur in war zones, but also in our daily lives - in sports matches and car crashes, among other accidents. The tests, measurements and computational models our researchers are developing can help save and improve these lives as well," Dhawan said. "This work will have impacts beyond the Center for Injury Biomechanics, Materials and Medicine, on research taking place in departments across the campus that are also focused on brain health and science, and in many cases, collaborating across disciplines, including cell biology, physiology, instrumentation, imaging and computer modeling."

He added, "We expect their work to produce technological advances with implications for brain imaging and neurophysiology as well, that we hope will aid in the diagnosis and characterization of neurological diseases such as strokes, epilepsy and Parkinson's disease."