 This study will use a novel approach to monitor the health of older adults following a moderate severe traumatic brain injury, TBI. It will utilize passive and wearable sensors to measure physical, functional and cognitive outcomes, as well as changes in sleep and activity patterns. This information will be analyzed using machine learning techniques to identify any changes in routine behavior and predict clinical events. Additionally, qualitative interviews will be conducted with patients, caregivers and clinicians to assess the acceptability and utility of the system. This article was authored by Parish Malhotra, David J. Sharp and others.