When the Virginia Tech Hokies football team takes the field, 18 of the players are connected to a computer that sits quietly on the sidelines. Every hit, every tackle and every fall is recorded in a Sybase database that keeps track of head impacts.
Eventually, the data being gathered on the Virginia Tech football players as well as other participants in other sports will become part of a nationwide database that is intended to reduce concussions and the injuries that stem from them.
"We hatched this idea to use small accelerometers inside the helmets with a small chip to transmit the information to the sidelines," said Dr. Gunnar Brolinson, team physician for the football players at Virginia Polytechnic Institute and State University in Blacksburg, Virginia. Brolinson is also chief of the division of sports medicine at the Virginia College of Osteopathy, also in Blacksburg.
"When I came to Virginia Tech I got in touch with Stefan Duma, who is director of the impact biomechanics lab at Virginia Tech," Brolinson said. Duma had already established his lab as a top research facility for the study of head injuries related to car crashes. Brolinson said that he wanted to study concussive forces and concussions in athletics, which had similar biomechanics issues.
Brolinson worked with Simbex, based in Lebanon, N.H., which was already working to measure head injuries and develop a wireless telemetry system that fits inside a football helmet without interfering with the players use of the helmet. To do this, they also worked with Riddell—part of Easton-Bell Sports—which makes nearly all of the football helmets used at the college and professional levels.
"Simbex developed the HITS (head impact telemetry system) initially because theres a large gap in the information as to what causes brain injury, especially in sports. But theres this big hole about how people got the injury," said Simbex president Rick Greenwald. "We wanted to understand the injury from a biomechanical basis so we could come back to changes in equipment and rules."
Greenwald said the technology works by taking small accelerometers, similar to what are used in car airbag systems, and placing them against the head.
"We place them in the helmet with a radio transmitter that can reach across an entire football field, and it can relay information about impacts that are occurring during the game," he said.
Greenwald said that the helmet-based telemetry systems use a frequency hopping spread spectrum wireless transmitter that works in the 900MHz band. He said that as more teams adopt the technology, the radio signals will be differentiated so that one team wont receive the others telemetry.
"We initially started out with eight instrumented helmets and rotated them among players," Brolinson said. "We needed to get a feel for the type of impact we were seeing, get an idea of the direction of the blows they were receiving. The first year was spent getting a feel for the technology," he said.
Things have expanded since then, as Brolinson now has around 18 players that are instrumented, and they remain instrumented for the entire season.
"The idea is that concussions are a very common thing. There are 1.5 million traumatic brain injuries on a national basis in a given year and about 300,000 are athletes. Football has the largest total," Brolinson said.
"One of the things that is important is to understand the biomechanics," Brolinson added. "This system has allowed us to dig into the kinds of loads and motions that give a concussion to the athlete. It allows us to study this in a real environment."
Greenwald said that one of the factors that make this study important is that the information can be learned in real time. The system that allows for recording real time impacts on the field and it provides a clinical tool for the medical staff to see injuries they might otherwise have missed in the busy environment of a football field, Greenwald said.
The telemetry information is sent from the wireless transmitter to a Sybase database thats running on a laptop computer located on the sidelines of the football field.