Even through traumatic brain injury has the word "traumatic" in it, it's often the case that soldiers in combat are exposed to things blowing up that leave mild to moderate brain injuries that go undetected. DARPA's new field blast gauge is designed to help medics tell exactly how much blast exposure someone has, and whether they need treatment.
Somewhat unusually for a DARPA project, the blast gauge only cost about a million dollars to develop, and after less than a year, it's just about ready for field trials. Designed to be cheap enough to be worn by individual soldiers, the gauges can be worn on helmets, attached to clothing, or mounted on vehicles. If something bad happens, it records exactly what went on, and then those data can be downloaded via USB or read directly on some handy little lights on the device itself for immediate triage.
This video shows some of the testing that DARPA put the blast gauge through; if you pay close attention at about the 1:00 mark, you can see both the initial blast wave plus a second wave that reflects off the ground, illustrating why having a sensitive piece of equipment to catalog exactly what went on is such a good idea.