Flexible Electrode Array for EOG Gaze Tracking
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Solution Overview
Problem
Current electro-oculogram (EOG) electrode configurations are cumbersome, impractical for frequent use, and limited in their ability to accurately assess eye movements, particularly convergence, due to their rigid design and limited number of electrodes, which restricts their application in tracking gaze position and movement with high accuracy.
Innovation Solution
A self-adhesive flexible electrode array with a plurality of electrodes positioned around the eyes, eyebrows, and nose, fabricated on a flexible substrate such as plastic or polymer films, which conforms to facial contours and improves signal-to-noise ratio, allowing for more precise tracking of both vertical and horizontal eye movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional rigid electrodes with few measurement points are used, then the device complexity is reduced, but the measurement precision of eye movements particularly convergence is insufficient
Solution Approach 1:
The electrode array is segmented into multiple functional groups: horizontal measurement electrodes (100) for detecting horizontal eye movements, vertical measurement electrodes (101) for detecting vertical eye movements, and medial measurement electrodes (102) for detecting convergence movements. This segmentation allows precise measurement of different eye movement types independently, resolving the contradiction between measurement precision and device complexity by organizing complexity into functional segments.
Solution Approach 2:
The invention transitions from conventional 1D or 2D electrode placement to a comprehensive 3D spatial arrangement around the eye, incorporating horizontal, vertical, and medial dimensions. This dimensional expansion enables simultaneous measurement of multiple eye movement planes, achieving high measurement precision while the modular array design keeps device complexity manageable.
2Measurement precision
If multiple electrodes are placed around the eyes for accurate gaze tracking, then the measurement precision improves, but the ease of operation deteriorates due to cumbersome placement
Solution Approach 1:
Multiple individual electrodes are merged into a single flexible substrate array that can be applied as one unit to the face. This integration maintains the measurement precision benefits of multiple electrodes while dramatically improving ease of operation, as the entire multi-electrode array can be positioned and secured in a single application process rather than placing each electrode separately.
Solution Approach 2:
The electrodes are mounted on a flexible substrate that can conform to the contours of the face and wrap around the eye area. This flexibility enables the multi-electrode array to be easily positioned and secured to the subject's face, improving ease of operation while maintaining the precise spatial arrangement of electrodes needed for accurate gaze tracking.
3Ease of manufacture
If conventional metal electrodes with leads are used, then the manufacturing precision is easier to achieve, but the ease of operation worsens due to discomfort during prolonged recording
Solution Approach 1:
The invention replaces rigid metal electrodes with flexible thin-film electrodes deposited on a flexible substrate. This transformation maintains ease of manufacture through established thin-film deposition techniques while dramatically improving comfort during prolonged recording, as the flexible material conforms to the skin and eliminates the discomfort associated with rigid metal contacts and attached leads.
Solution Approach 2:
The invention replaces the mechanical lead-wire connection system with integrated flexible printed circuit traces on the substrate. This substitution eliminates the need for external leads and connectors that cause discomfort, while maintaining electrical connectivity through the flexible substrate itself, thereby improving ease of operation during prolonged recording without sacrificing manufacturability.
4Measurement precision
If a dense array of electrodes is implemented, then the measurement precision of eye movements improves, but the device complexity increases
Solution Approach 1:
The dense electrode array is segmented into functionally distinct groups (horizontal electrodes 100, vertical electrodes 101, medial electrodes 102) with specific spatial arrangements optimized for different measurement types. This segmentation reduces perceived device complexity by organizing the dense array into manageable functional units, while maintaining the high measurement precision benefits of the dense configuration.
Solution Approach 2:
The flexible substrate array is designed as a universal platform that can detect horizontal eye movements, vertical eye movements, and convergence movements simultaneously through its multi-functional electrode configuration. This universality reduces device complexity by consolidating multiple measurement capabilities into a single integrated array, eliminating the need for separate electrode sets for different measurement types.
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 flexible electrode array enhances the accuracy of eye-gaze tracking by increasing the number of data sources, reducing discomfort, and enabling prolonged recordings, making it more practical for routine use in various settings.
Implementation Method 1
The discrete nature of the EOG recording apparatus allows the subject to wear corrective lenses if necessary... An alternative method of recording gaze and eye tracking movements is referred to as the electro-oculogram (EOG) which measures the measures electro-potential difference between the retina and the cornea
Implementation Method 2
A self-adhesive flexible electrode array with a plurality of electrodes positioned around the eyes, eyebrows, and nose, fabricated on a flexible substrate such as plastic or polymer films, which conforms to facial contours
Data Source
AI summary
This invention is directed to a bio-potential electrode-set for measuring electrical signals during an electrooculogram (EOG) from a human, particularly to flexible self-adhesive bio-potential sensing electrode-set substrate specifically to cover the perimeter of the eyes for EOG recordings. In general, EOG is a technique for measuring the cornea-retinal standing potential that exists between the front and the back of the human eye. The resulting signal is called the electrooculogram. Primary applications include, but are not limited to, ophthalmological assessments that require recording eye movements or gaze tracking and human computer/machine interfaces.