Helmets are designed to protect athletes in many sports from head injuries, but a helmet that doesn’t fit properly could leave the athlete vulnerable to traumatic brain injury. To mitigate this danger, researchers at Western Michigan University have developed a pressure-sensing cap, worn under the helmet, that can provide specific data to show whether a helmet is sized correctly. The cap, developed by Ph.D. student Simin Masihi, professor Massood Atashbar and colleagues, is equipped with 16 fabric-based sensors that map pressure in real-time and quantify the amount of pressure being exerted on each sensor. When tested on multiple volunteers wearing a helmet of the same size, the cap accurately indicated that the person with the largest head experienced the greatest amount of pressure. With further development, the technology could be used to help athletes select the right off-the-shelf helmet, as well as support production of custom-fit helmets. Photo: Massood Atashbar/Western Michigan University.