Tuesday, November 29, 2011

Groundbreaking research looks at how blasts injure brain


LANDSTUHL, Germany — During a firefight in Afghanistan’s Kandahar province in 2002, U.S. Army Maj. Kevin Kit Parker stood atop a hill awaiting a Medevac flight for an injured soldier when a bomb exploded several miles away.

He saw the bomb’s intense light first, then felt its shock waves ripple through his body.

“It felt like it was lifting my bowels, and I was quite far away,” Parker said.

Several years later, when he was working in bioengineering research at Harvard University, a friend of Parker’s suffered a severe traumatic brain injury, and Parker was reminded of his Kandahar experience. Parker chose to shift his focus from cardiac tissue to brain research after receiving encouragement from Col. Geoffrey Ling, a neurologist and program manager at the Defense Advanced Research Projects Agency, or DARPA.

Now a professor at Harvard, Parker has published groundbreaking research describing how blasts injure the brain. Gathering data directly on the battlefield from servicemembers who’ve been in close proximity to blasts, he said, will be key to understanding the devastating yet subtle damage caused.

The military currently is fielding several new technologies in Afghanistan to do exactly that. Now:

● Soldiers are being outfitted with high-tech gauges that can detect a blast’s severity and alert medics on site that a soldier has been exposed to shock waves.

● Armored vehicles are equipped with sensors that connect to each vehicle’s “black box,” which measures and stores information on blasts.

Gauging blasts

But new research is adding credence to the theory that a blast’s shock waves can cause a brain injury. Traveling at more than 1,600 miles per hour after an explosion, these violent waves of air, called overpressures, penetrate the skull and reach the brain, researchers say.

Overpressures have long been known to cause other types of internal injuries, including collapsed lungs. New research suggests that a blast’s shock waves can stretch brain cells, causing them to tear, or force the long nerves between brain cells to expand and contract, damaging them, or stretch the blood vessel walls beyond their limit, causing an injury called vasospasms.

To measure the force of blast waves on troops near explosions, DARPA developed a blast gauge. About the size of a watch face and weighing an ounce, the portable blast gauge can be attached to helmets and body armor. Inside it are a microprocessor and sensors that detect the blast’s force and measure its overpressures, storing the data until it can be downloaded.

In addition to measuring the bomb’s force, the device is designed to give medics attending blast victims an instant read of their exposure to blast waves. The medic inserts a stylus or pen tip into the device, causing a light to flash green, yellow or red. The color indicates whether the blast was strong enough to require the soldier receive further medical attention and rest.

“Thank God this is coming out now,” Parker said. “We can’t get this in the field fast enough.”
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