fNIRS Sensor for Mental Engagement Detection in Driving
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Solution Overview
Problem
Current technologies lack a reliable method to predict visual perceptual task performance of individuals, particularly in driving scenarios, where a driver's mental state may be disengaged from the task, leading to impaired visual perception without overt indicators.
Innovation Solution
An electronic device using functional near-infrared spectroscopy (fNIRS) sensors to measure working memory load at the frontal cortex, predicting visual perceptual task performance by detecting increased brain activity associated with high mental engagement, which impairs visual perception, and a computer vision method to assess perceptual load from visual scenes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If EEG is used to measure mental engagement, then mental state can be assessed, but the measurement is strongly distorted by muscular activity and head movements
Solution Approach 1:
The patent replaces the electrical measurement system (EEG) with an optical measurement system (fNIRS). Instead of measuring electrical fields that are sensitive to muscular activity, the system uses near-infrared light to measure hemoglobin concentration changes in the frontal cortex, which are not affected by muscular movements or head motions.
Solution Approach 2:
The patent introduces hemoglobin concentration as an intermediary measurement. Rather than directly measuring brain electrical activity (which is distorted by muscles), the system measures blood oxygenation levels in the frontal cortex, which serve as a reliable proxy for working memory load and mental engagement without being affected by muscular activity.
2Measurement precision
If pupil dilation is measured to assess mental engagement, then working memory capacity can be evaluated, but the measurement is highly susceptible to ambient light intensity changes
Solution Approach 1:
The patent replaces the optical measurement of pupil size (which is light-sensitive) with near-infrared spectroscopy that measures hemoglobin concentration. This optical substitution uses a different wavelength range (near-infrared) that penetrates tissue and is not affected by ambient visible light conditions.
Solution Approach 2:
The patent changes the measurement parameter from pupil diameter (which varies with light intensity) to hemoglobin concentration in the frontal cortex. This parameter change allows assessment of working memory load while being insensitive to ambient light conditions, as fNIRS measures internal physiological parameters rather than external optical responses.
3Reliability
If fNIRS is used to measure working memory load, then reliable detection of mental engagement is achieved, but the device complexity increases
Solution Approach 1:
The patent applies fNIRS sensors specifically to the frontal cortex region, focusing measurement on the area most relevant to working memory functions. This localized approach improves reliability by targeting the specific brain region involved in working memory tasks, while keeping the sensor array size manageable compared to whole-brain coverage.
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
Enables reliable detection of 'mind off the road' states without environmental changes, providing non-intrusive brain activity measurements insensitive to light and muscular noise, and triggering warnings or adjusting automated driving systems.
Implementation Method 1
receive an output of a first sensor device configured to measure the working memory load at the frontal cortex of the human
Data Source
AI summary
The invention relates to an electronic device (1) for predicting the visual perceptual task performance of an individual human. The electronic device is configured to: •receive an output of a first sensor device configured to measure the working memory load at the frontal cortex of the human, and •predict the visual perceptual task performance as a function of said sensor output. The invention further relates to a system and a method.