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Updated: Dec 29, 2025

Using Eye-tracking to Assess the Relative Importance of Visual and Vestibular Input to Subcortical Motion Processing in the Roll Plane
Published on: August 22, 2025
Technical Note: Benchmarking automated eye tracking and human detection for motion monitoring in ocular proton
Riccardo Via1, Fabian Hennings1, Giovanni Fattori1
1Paul Scherrer Institut (PSI), Center for Proton Therapy, 5232, Villigen PSI, Switzerland.
Purpose:
Ocular proton therapy is an effective therapeutic option for patients affected with uveal melanomas. An optical eye-tracking system (ETS) aiming at noninvasive motion monitoring was developed and tested in a clinical scenario.
Materials And Methods:
The ETS estimates eye position and orientation at 25 frames per second using the three-dimensional position of pupil and cornea curvature centers identified, in the treatment room, through stereoscopic optical imaging and infrared eye illumination. Its capabilities for automatic detection of eye motion were retrospectively evaluated on 60 treatment fractions. Then, the ETS performance was benchmarked against the clinical standard based on visual control and manual beam interruption.
Results:
Eye-tracking system detected eye position successfully in 97% of all available frames. Eye-tracking system-based eye monitoring during therapy guarantees quicker response to involuntary eye motions than manual beam interruptions and avoids unnecessary beam interruptions.
Conclusions:
Eye-tracking system shows promise for on-line monitoring of eye motion. Its introduction in the clinical workflow will guarantee a swifter treatment course for the patient and the clinical personnel.

