Eye Gaze Tracking Calibration via Saccade Detection
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Solution Overview
Problem
Existing eye gaze tracking systems face challenges in accurately calibrating electro-oculograms due to the phenomenon of drift, which occurs when the baseline of the electro-oculogram changes over time, affecting the accuracy of gaze-point calculation.
Innovation Solution
An eye gaze tracking apparatus that includes an electro-oculogram measuring unit, a calibration index presenting unit, a saccade detection unit, and a calibration parameter calculating unit, which detects saccadic movements and calculates calibration parameters based on the changes in the electro-oculogram before and after these movements to eliminate the effect of drift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is performed using electro-oculogram and gaze-point data over time, then calibration accuracy should improve, but drift causes the baseline to change and reduces measurement precision
Solution Approach 1:
The system performs preliminary actions by detecting saccadic movements and using them to establish calibration parameters before normal gaze tracking begins. This preliminary calibration based on saccades provides a stable reference that is not affected by subsequent drift in the electro-oculogram baseline.
Solution Approach 2:
The invention changes the parameter used for calibration from absolute electro-oculogram values to changes in electro-oculogram values during saccadic movements. By focusing on the dynamic change rather than static baseline values, the system eliminates the effect of drift on calibration accuracy.
2Productivity
If continuous electro-oculogram monitoring is performed to track gaze-point, then tracking capability is improved, but drift accumulates and reduces reliability
Solution Approach 1:
The system implements feedback by continuously monitoring electro-oculogram signals and using detected saccadic movements to update or verify calibration parameters. This feedback mechanism allows the system to maintain accurate gaze tracking over time by periodically referencing the drift-resistant saccade-based calibration.
Solution Approach 2:
By establishing a preliminary calibration based on saccades that is resistant to drift, the system creates a stable reference framework that enables reliable continuous monitoring without the accumulation of drift errors that would otherwise reduce accuracy over time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively calibrates the electro-oculogram and gaze-point by using saccadic movement changes, providing accurate calibration parameters that are not affected by drift, thereby improving the reliability of eye gaze tracking.
Implementation Method 1
an EOG that utilizes a potential generated between a cornea and a retina
Data Source
AI summary
An eye gaze tracking apparatus (100) includes: an electro-oculogram measuring unit that outputs an electro-oculogram original signal; a calibration index presenting unit (103) that presents a calibration index to a user; a saccade detection unit (104) that outputs an electro-oculogram change amount that is an amount of change in an electro-oculogram before or after a saccadic movement which is measured when a gaze-path position of the user moves to the calibration index; a calibration parameter calculating unit (105) that calculates a calibration parameter based on a position of the calibration index and an electro-oculogram change amount; and a calibration unit (101) that detects the gaze-path direction of the user from the electro-oculogram original signal.