Application of MEMS Inertial Sensors in Sensing Passive Eye Response as a Surrogate for Brain Response to Head Acceleration and Rotation for On-field Objective Assessment of Concussion

Abstract

The passive eye response (PER) may act as a surrogate for the brain response to head acceleration during a concussion causing impact. A novel eye movement sensor designed in this dissertation is used to verify this hypothesis and to predict the risk of mild traumatic brain injury (mTBI). Microelectromechanical systems (MEMS) accelerometers are proven to capture the relative displacement of the eye to the bony socket/skull in a similar fashion to the brain. Expansion to dynamic systems is achieved by applying 6-DoF MEMS inertial measurement units (IMU), which are tested on a skull-brain-eye model and human volunteers in drop-and-impact experiments. An advanced sensor fusion technique is designed and applied in processing the IMU data. Similar angular accelerations of eye and brain relative to skull are observed in the IMU data during rotation tests. Strong correlations of eye and brain accelerations are discovered in the drop-and-impact model tests suggesting that sensing the PER using IMU's could provide better outcomes than sensing head acceleration for real-time on-field objective mTBI monitoring, assessment, and diagnosis.