Eye Motion Sensing via Flexible Contact Magnet and External Coils
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Solution Overview
Problem
Current eye motion detection methods, such as imaging sensing and coil sensing, suffer from low precision and susceptibility to interference, making them inadequate for accurate and stable eye motion analysis.
Innovation Solution
An eye motion sensing method utilizing a flexible contact body with a permanent magnet implanted around the pupil area, coupled with external sensing coils arranged in a cross configuration, generates a servo motion signal through an induced magnetic field, which is converted into an electromotive force to restore accurate eye motion signals, enhancing detection precision and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If imaging sensing method is used to detect eye motion, then detection can be performed, but measurement precision is relatively low due to great error in pupil image analysis
Solution Approach 1:
The patent replaces the optical imaging system with a magnetic field-based sensing system. A permanent magnet is implanted in the flexible contact body that contacts the eye, and external coils detect the magnetic field changes caused by eye motion. This substitution of mechanical/optical system with electromagnetic system eliminates the errors associated with image analysis and provides more precise and reliable measurements.
Solution Approach 2:
The patent changes the detection parameter from optical image characteristics to magnetic field parameters. By detecting the position and motion of the permanent magnet through external coils, the system transforms the measurement from analyzing pupil image geometry to measuring magnetic field variations, thereby improving precision and reliability.
2Measurement precision
If dual induction coil sensing method is used, then eye motion can be detected, but measurement precision is relatively low due to weak secondary induction phenomenon
Solution Approach 1:
The patent extracts and eliminates the intermediate induction step that causes signal weakness and interference. Instead of using two groups of coils where one induces current in the other (secondary induction), the invention directly places a permanent magnet in the contact body and uses external coils to detect its position directly, removing the weak secondary induction link and its associated problems.
Solution Approach 2:
The patent introduces a permanent magnet as a direct intermediary between the eye motion and the external sensing coils. This permanent magnet serves as a stable magnetic field source that directly translates eye motion into detectable magnetic field changes, eliminating the need for electromagnetic induction chains and reducing interference susceptibility.
3Reliability
If end-to-end induction coil is attached to eyeball, then eye motion can be detected, but anti-interference capability is relatively low
Solution Approach 1:
The patent uses a permanent magnet to create a stable, reproducible magnetic field signature that copies the eye motion pattern. This magnetic signature serves as a reliable reference that can be detected externally without being affected by electromagnetic interference, thereby improving anti-interference capability and detection stability.
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
This method allows for precise detection and analysis of eye movements, including tiny saccades and nystagmus, providing valuable information on brain behavior patterns and changes caused by defects or training, with improved accuracy and resistance to interference.
Implementation Method 1
If an eye motion occurs, the induction coil induces a high frequency current. A high frequency magnetic field generated by the induction current is further induced into the detection coils, so as to detect the eye motion.
Data Source
AI summary
The present invention discloses an eye motion sensing method, a flexible contact body, an external sensing coil, and a system. The method may include: sensing an eye motion by using a servo motion signal of a permanent magnet implanted into a flexible contact body; applying at least four coils disposed externally on a same plane, and monitoring a servo motion of the permanent magnet according to an electromotive force in the coils; and converting the electromotive force to restore an eye motion signal. The present invention can use the sensing coils distributed around an eyepit to detect the electromotive force generated when the eye motion leads to the servo motion of the flexible contact body, and analyze the electromotive force. Accordingly, the eye motion triggered by a perceptual task can be analyzed objectively.