WASHINGTON, Jan. 14, 2008 - While it still may be years away, military medical officials hope to one day place a sensor on every troop that would measure a blast's impact and alert a combat medic to the possibility of a brain injury.The latest fielding of helmets fitted with blast sensors to troops deploying to combat could be the first step to gathering the data to support that technology, Michael J. Leggieri Jr., deputy coordinator for DoD's Blast Injury Research Program Coordinating Office, said.Brigades from the 101st Airborne and the 4th Infantry divisions will wear helmets fitted with sensors throughout their deployments to Afghanistan and Iraq, respectively. The sensors will record routine impact data, as well as any blasts, or "events," to which the soldiers are exposed.Leggieri is quick to point out that at this stage, however, the data will not be used in diagnosing or treating soldiers. Still in its infancy, the technology's first hurtle will be to prove that a sensor reading can be matched to an event, he said."We need to figure out if we can actually, with some confidence, say that 'Yes, these data are representative of an ... event.' We don't know that yet," he explained.The sensor data will be recorded along with other operational data that is typically gathered after an event such as a bomb explosion. That data is entered into an intelligence database with the National Ground Intelligence Center that already is in use in the field. At the same time, if an injury occurred, patient data is recorded in a trauma registry also already in place.The two databases are kept separate, Leggieri said."These helmet sensors, they are not medical devices. The data that they record are not medical data. So you can't take, and we won't allow anyone to take, the raw sensor data and make any kinds of decisions about medical treatment, or injuries or anything else," Leggieri said.After the blast data is studied, and officials determine that it is reliable, they will then go back and match the event data with injury data. The medical community has access to the data through the Joint Trauma Analysis and Prevention of Injury in Combat Program. Officials want to see if they can make a connection between what is seen on the sensor reading and any resulting injury. This will help them to begin "unraveling" some of the causes of brain injury, Leggieri said."We know that if you hit your head against something, or if something hits your head, that you can get a brain injury. But the mechanism, at the cellular level -- how does that happen' There are still a lot of unknowns there," Leggieri said.For example, Leggieri said that despite reports that exposure to a blast - or primary blast overpressure - can cause mild traumatic brain injury, there are no definitive studies to show that link."We don't know, in fact, if being exposed to primary blast overpressure can cause a mild traumatic brain injury. And, if it can cause a mild traumatic brain injury, we don't know what that mechanism would be," he said.The specific cause of the injury, or the mechanism, is used to develop protection strategies and to design diagnostic tools and treatments.Within the next year, if the data proves reliable, the impact data may be used as an "event monitor," Leggieri said. Similar devices are used in football players' helmets, where a particularly hard hit would signal a doctor's need for review. Combat leaders on the ground could use the data to refer the servicemember to medical officials who would then use diagnostic tools to determine if an injury occurred.But, first things first, Leggieri said. What makes this project valuable, he explained, is that researchers will be able to gather actual impact data from soldiers in combat, as opposed to research conducted in a laboratory."Right now we are getting an understanding of what happens out there - what kinds of impacts are the soldiers seeing - trying to understand that first, and then linking it to resulting injuries," he said.Currently, data collection from only these two deployments is planned.The sensor model fielded to 101st Airborne Division attaches to the back of the advanced combat helmet. It weights about 6 ounces and has enough memory to store data on 527 events. An internally mounted model will be fielded to the 4th Infantry Division. The sensor sits under the padding in the crown of the helmet. To harvest information from either sensor type, a soldier simply connects it to a computer using a USB port, hits "save" and sends the data to a secure database.