Eye Tracker Accuracy: Quantitative Evaluation of the Invisible Eye Center Location

摘要

Purpose. We present a new method to evaluate the accuracy of an eye trackerbased eye localization system. Measuring the accuracy of an eye tracker'sprimary intention, the estimated point of gaze, is usually done with volunteersand a set of fixation points used as ground truth. However, verifying theaccuracy of the location estimate of a volunteer's eye center in 3D space isnot easily possible. This is because the eye center is an intangible pointhidden by the iris. Methods. We evaluate the eye location accuracy by using aneye phantom instead of eyes of volunteers. For this, we developed a testingstage with a realistic artificial eye and a corresponding kinematic model,which we trained with {\mu}CT data. This enables us to precisely evaluate theeye location estimate of an eye tracker. Results. We show that the proposedtesting stage with the corresponding kinematic model is suitable for such avalidation. Further, we evaluate a particular eye tracker based navigationsystem and show that this system is able to successfully determine the eyecenter with sub-millimeter accuracy. Conclusions. We show the suitability ofthe evaluated eye tracker for eye interventions, using the proposed testingstage and the corresponding kinematic model. The results further enablespecific enhancement of the navigation system to potentially get even betterresults.