Project Description: 

Project Halo’s objective is to mitigate cognitive deficits resulting from blast exposure in Army Ranger mortarmen. Rangers are exposed to blasts in combat and training that can result in poor health outcomes, ranging from short-term cognitive deficits to traumatic brain injury (TBI). An understudied source of blast exposure is repetitive, low-level blasts from the firing of major concussive weapon systems. The mortar system specifically has no firing limitations. To better understand this blast exposure, Project Halo conducted an experiment at Ft. Benning military base to characterize the blast overpressure and cognitive deficits associated with mortar firing. The team found that mortarmen are exposed to an upwards of three times the US Army-established safety threshold of 4 psi. Additionally, cognitive symptoms such as headaches, ringing ears, irritability, and foggy thinking were reported. To address this problem, the team first identified various design inputs for a device. The team’s critical design inputs included reducing blast overpressure exposure to below the US Army safety threshold and allowing safe and proper loading of ammunition. The team generated over 100 design concepts and chose a final concept of a blast attenuator device (BAD). Project Halo then iteratively prototyped various BAD designs based off of user feedback and experimental observations. To test critical inputs of the design, the team conducted computational fluid dynamic modeling, finite element analysis, and shear-load testing. After final confirmation with users at Ft. Benning, the team decided on a final optimized BAD design. Project Halo’s BAD can reduce blast exposure by at least 30% by redirection of blast overpressure up and away from mortarmen. The team believes this device can save up to 12.6 million dollars in medical costs associated with blast-related traumatic brain injury treatment.