Hearable System for Impact and Blast

The high incidence of Traumatic brain injury (TBI) in the military has long-term consequences for force readiness and for service members’ health. Repeated mild traumatic brain injuries (mTBI) also affect performance and build to permanent damage while making individuals more susceptible to further TBI from subsequent impact or blast events. Hearing damage is another consequential injury. It is the most prevalent disability among Veterans and affects mission performance during service and post-service quality of life.  Monitoring impact and blast exposure will enable the military to protect service members’ health by evaluating the effectiveness of protective equipment and by structuring training to reduce injuries. Various monitoring devices developed to date suffer from inadequate integration and poor coupling to the head. Furthermore, these devices fail to accurately capture actual exposure because they measure the external field and do not account for the level of protection provided by personal protective equipment (PPE). More accurate data would result from sensors positioned inside the PPE, closer to the critical site of damage, which is the brain. The most attractive of potential sites is the ear.  Paxauris has seized the opportunity to develop an in-ear device that provides improved hearing protection, clear communications, and enhanced situational awareness while also monitoring exposure to blast, impact, and noise. By measuring blast overpressures in the ear canal, inside the wearer’s hearing protection, we can obtain measurements that correlate well with the brain overpressures while using sensors with lower bandwidth and dynamic range than required to capture the external blast wave. The multiple sensors in our Blast and Noise Safety Hearables for Extreme Environments (Banshee™) capture the full range of damaging exposure, from continuous engine noise, through impulses from weapons fire, to explosive blast events. Sensor signals are processed into exposure damage metrics that are recorded on a body-worn monitor that warns when safe exposure levels are exceeded. Individual metrics are downloaded when in range of a work station, where a Dashboard shows the status of all members in a team. In Phase I of this project, we proved the feasibility of our concept for integrated blast and impact sensors. In Phase II we developed the complete system and demonstrated the performance of our hearables in impact tests and with simulated blasts from shock tubes. We repeated these tests with our hearable fitted in the ears of a biofidelic head simulator and a post mortem human subject (PMHS) head and we also conducted fit and motion detection tests with human subjects.  In this Sequential Phase II, we will further mature the system and implement improvements identified during our previous tests.