Pupil Frequency Tagging Biomarker for Color Perception
Solution Overview
Problem
Current methods for evaluating color perception in mammals, such as those based on optokinetic responses, require sophisticated equipment and precise analysis of eye movements, making them challenging for non-cooperative subjects like animals and babies, and are subjective in nature.
Innovation Solution
A method utilizing the slower pupillary response to a dynamic multicolored stimulus with periodically inverted colors, allowing for the generation of a biomarker of color perception using less sophisticated equipment and without the need for precise eye movement analysis, by acquiring and processing oscillatory pupil responses at a low marking frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optokinetic response methods are used to evaluate color perception, then measurement precision is improved, but device complexity increases and ease of operation deteriorates
Solution Approach 1:
The patent replaces complex mechanical/optical eye tracking systems with a simplified pupillary response measurement system. Instead of tracking eye movements requiring sophisticated cameras and processing, the invention measures pupil diameter changes using basic imaging equipment, substituting a complex mechanical measurement system with a simpler physiological response measurement approach.
Solution Approach 2:
The patent introduces the pupillary response as an intermediary indicator to indirectly measure color perception. Rather than directly measuring eye movements or subjective perceptions, the system uses pupil diameter changes as a mediator that reflects chromatic isoluminance, simplifying the measurement chain while maintaining accuracy.
2Measurement precision
If optokinetic response methods are used to evaluate color perception, then measurement precision is improved, but ease of operation deteriorates due to calibration requirements
Solution Approach 1:
The pupillary response measurement system is inherently self-calibrating through the physiological characteristics of the pupil. The natural pupillary response to light provides built-in reference points, eliminating the need for external calibration procedures. The system automatically adapts to individual subject characteristics without requiring operator intervention for calibration.
3Measurement precision
If eye movement analysis is used to evaluate color perception, then measurement precision is improved, but productivity decreases due to processing requirements
Solution Approach 1:
The patent extracts the essential measurement signal from complex eye movement analysis by focusing specifically on pupil diameter changes. This extraction of the key physiological response eliminates the need for sophisticated real-time processing of entire eye movement sequences, reducing computational requirements while preserving the critical information needed for color perception assessment.
4Measurement precision
If chromatic isoluminance assessment is used to evaluate color perception, then measurement precision is improved, but ease of operation deteriorates due to subjective judgment requirements
Solution Approach 1:
The patent replaces subjective perceptual judgment with objective physiological measurement. Instead of relying on subjects' subjective reports of color perception, the system measures objective pupillary responses to chromatic stimuli, substituting subjective psychological assessment with objective biophysical measurement that eliminates observer bias.
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 approach provides a reliable, objective, and simpler method for assessing color perception, reducing equipment requirements and eliminating the need for calibration, while maintaining high signal quality and noise resistance.
Implementation Method 1
relying on the pupil's response to changes in luminance. Indeed, since this response (pupil contraction or dilation) is slower than nystagmus
Data Source
Figure 1~2
Figure 3(a)~3(e)
Figure 4
AI summary
The invention relates to the evaluation of the colour perception of mammals for obtaining a biomarker characteristic of each subject tested. It takes advantage of the slow pupillary oscillation response to generate an objective neurological signature of said colour perception. A pupil frequency tagging method is used at a tagging frequency Ftag adapted to the speed of the pupillary response. A dynamic two-coloured stimulus is displayed, comprising a two-coloured motif, both colours being inverted at the frequency Ftag and one of the colours varying progressively through a range of possible values. On the basis of the pupillary response, a signal representing the power of the oscillatory response of the pupil is generated. The minimum of the signal corresponds to the relative isoluminance of the pair of colours tested.