Sensing Passive Eye Response to Impact Induced Head Acceleration Using MEMS IMUs

Area of Science:

• Biomechanics
• Neuroscience
• Medical Devices

Background:

• The brain's response to head acceleration during impact is critical for understanding concussions.
• The eye's movement dynamics may serve as a surrogate indicator for brain injury.
• Current methods for measuring head impact often lack direct correlation with internal brain response.

Purpose of the Study:

• To develop and validate a novel technique for measuring passive eye movements using microelectromechanical systems (MEMS) inertial measurement units (IMUs).
• To assess the feasibility of using the eye as a surrogate for the brain in dynamic impact scenarios.
• To quantify relative eye-to-head motion during impact events to better understand concussion mechanisms.

Main Methods:

• Utilized ribbon-style flexible printed circuit board IMUs inserted into the eye socket and reference IMUs on the head.
• Conducted drop-and-impact experiments using a 3D-printed scaled human skull model and human volunteers.
• Employed a microcontroller unit for data acquisition and data fusion techniques for processing and displacement estimation.

Main Results:

• Successfully validated the IMU-based technique for sensing passive eye movements during dynamic impacts.
• Estimated displacements of the eye relative to the head, showing good agreement with measured parameters.
• Computed relative accelerations and displacements, providing insights into the influence of concussion-causing impacts.

Conclusions:

• Passive eye movements, when measured with IMUs, can effectively act as a surrogate for brain response to head impacts.
• The developed methodology offers a promising approach for analyzing head injury biomechanics and concussion risk.
• This technique has potential applications in sports safety, automotive safety, and clinical diagnostics for traumatic brain injury.