Navy researchers are developing a system that could help determine the severity of a brain injury suffered by a warfighter following an explosion.
The wearable, sensor-based, three-part Blast Load Assessment Sense and Test -- or BLAST -- is sponsored by the Washington-based Office of Naval Research and involves its Naval Research Laboratory, the University of North Carolina, NASA and New Mexico-based research firm Applied Research Associates Inc.
Though invisible, traumatic brain injury or TBI has been called the signature wound to emerge from the military campaigns in Afghanistan and Iraq. The Pentagon and U.S. Department of Veterans Affairs have spent millions researching and developing tools to detect TBI and treat service members.
More than 357,000 have been diagnosed since 2000, according to the Defense Department's Defense and Veterans Brain Injury Center. Of that total, 294,000 cases have been of the mild variety, better known as a concussion.
"A concussion causes the brain to be extremely vulnerable to any other type of stimulation," said David A. Hovda, director of the University of California Los Angeles' Brain Injury Research Center. Hovda has worked with the military on past TBI projects but is not involved in BLAST.
The five-year, $30 million program will use sensors in helmets to take "real time" measurements of overpressure, or the shockwave propelled by an explosion, as well as acceleration and deceleration of the body during the exposure, said Dr. Timothy Bentley, the program manager overseeing BLAST for the Office of Naval Research's Warfighter Performance Department.
An algorithm being developed -- the second component of the program -- will convert that data to develop a threshold for injury that will be used to determine if the affected warfighter needs an additional exam.
If that's the case, a tool that's being developed to assess neurofunction -- BLAST's third component -- would be used. The tool would fit into a medic's hand and check for TBI by assessing whether the injured warfighter responds to a pattern of vibrations emitted by the device.
"When you're injured mildly, you don't want to get another injury on top of that because they don't add up linearly," Bentley said. "One plus one doesn't equal two, but one plus one may equal three, even, because you're weakened."
The high-profile deaths of several professional athletes in recent years, most notably among National Football League players, helped raise public awareness of TBI. While the effects of even the most mild TBI may not be immediately apparent, some experts have said exposure to blast or head trauma even off the battle- or playing field may later reveal itself in symptoms including headaches, depression, personality change or dementia.
There also is evidence that TBI may increase the risk for developing degenerative neurological diseases including Alzheimer's or chronic traumatic encephalopathy, which causes the brain to atrophy and, for now, is only diagnosed after death.
"There's no sort of advanced or speed testing for human aging in brains," Bentley said.
Data from BLAST also could lead to changes in Pentagon policy that currently requires service members within 50 meters of a blast -- about half a city block -- to rest for at least 24 hours.
That policy doesn't have a "great medical basis," Bentley said. But BLAST could improve response to exposure by giving more information to commanders and medical personnel that can signal when an affected warfighter needs to be pulled out for treatment or can return to the fight.
"It was a great policy, a good plan, but now what we've done is we've added some more medical information, exposure information, and then better medical tests," Bentley said. "We've learned a great deal about how brains get injured now, much more than we knew previously."
Bentley said sensors being used in the program could have a battery life of up to a year and be customized by serial number to track the wearer. Other details about the program, including the number of sensors worn at a time, have yet to be determined.
BLAST could be tested in a year although its rollout, if approved, is still several years away, he said.