Expanding Helmet Design Methodologies Through Brain Functional Area Representative Threat Models

In combat zones, warfighters may be exposed to multiple threat types that can result in impacts to the head. These head impacts can lead to traumatic brain injury (TBI) or other functional or cognitive impairments, depending on the impact location, duration, and severity. Personal protective equipment mitigates the damage to the head, and current equipment design efforts focus on high-level protective metrics such as local helmet deformations and penetrations, as well as global accelerations or rotations of the head. Advances in brain imaging and mapping have made it possible to couple brain regions with specific functions, which could lead to higher resolution injury models and a more integrated helmet design process.The Naval Research Laboratory has developed a design tool to relate cognitive and functional brain regions from the literature to representative threat models for a head-helmet system. In this study, the philosophy and methods behind this augmented design tool and some of its applications are discussed. Through surveying detailed brain mappings and Brodmann functional areas, spatial coordinates for a coarse and a fine brain model were identified, scaled, and positioned within a three-dimensional model of the head. Projectile threats to the brain from all directions were simulated to evaluate the vulnerability of specific brain regions for a given protective helmet geometry. Using this platform, a variety of design tools were developed to investigate the functional effects of making geometric changes to the helmet.© 2013 ASME