stefan, dumer head of virginia tech's biomedical department has been much. >> the mission is not to endootball, but understand what is better. research? >> we can tell a college player, what exposure you have, if you are a quarterbacker, lion backer - we can tell you what the exposure is. >> that impact simulated 100 gs of slartion on the -- acceleration on the brain. is. >> that's the kind of force you may experience in a serious car crash. so right here on this diagram you can see the impacts that players are taking. >> this is how professor dumer collects his detat with hits, he picks up the angle and acceleration of the head any time a player is hit. >> so the system is showing real-time impacts? >> basically within a couple of seconds of the impact it comes into the antenna and we can see live what happens to the players. >> you can plot this out through a practice or on entire season. >> we were one of the first teams to limit exposure and practices. we had data saying we are getting really high exposure and practice. the data allowed us to see that. >> in 2011 virginia tech teame