Petty Officer 2nd Class Michael J. Pena, 26, from Munford, Tenn., aviation physiology technician with Alpha Surgical Company, 1st Medical Battalion, 1st Marine Logistics Group (Forward), performs an internal scan to make sure a simulated patient's heart is functioning normally inside a Mobile Trauma Bay at Camp Dwyer, Afghanistan, April 27. An MTB is an armored container on top of a Logistics Vehicle System Replacement, consisting of one doctor, one nurse and three corpsmen, that brings medical treatment closer to the battlefield.