Brain Function Measurement Device Using Polarized Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current brain function measurement techniques using near-infrared spectroscopy face issues with motion artifacts due to unstable probe positions and lack of clear criteria for identifying signal fluctuations, leading to inconsistent removal of motion artifacts.
Innovation Solution
A brain function measurement device and method involving linearly polarized light irradiation, blocking of directly reflected light components by hairs, and detection of light intensity to improve measurement reliability, using a multidistance probe arrangement and neutral-density filters to normalize light intensities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If probes are placed on the head for brain function measurement, then measurement can be conducted non-invasively, but the positions of the probes become unstable due to gaps between hairs
Solution Approach 1:
The patent segments the light detection into two distinct paths: directly reflected light (which causes motion artifacts) and transmitted light (which contains brain function information). By using separate detection channels for reflected light intensity and transmitted light spectrum, the system can isolate and eliminate the harmful reflected component while preserving the useful transmitted component.
Solution Approach 2:
The patent extracts and removes the directly reflected light component from the detection signal. By measuring reflected light intensity separately and using it to cancel out the reflected component in the transmitted light signal, the system extracts only the useful brain function information while discarding the motion artifact-containing reflected component.
2Measurement precision
If motion artifact removal techniques are applied, then data quality may improve, but the criteria for identifying motion artifacts are not clearly defined leading to inconsistent results
Solution Approach 1:
The patent changes the detection parameters by measuring both reflected light intensity and transmitted light spectrum simultaneously. This dual-parameter approach provides clear, objective criteria for identifying and removing motion artifacts based on the physical properties of light interaction with hair and brain tissue, eliminating the need for ambiguous motion artifact identification criteria.
Solution Approach 2:
The patent uses reflected light intensity measurement as feedback to cancel out the reflected component in the transmitted light signal. This feedback mechanism provides a clear, automated criterion for motion artifact removal, improving consistency by systematically eliminating reflected light based on measured intensity variations rather than ambiguous identification.
3Productivity
If probes fluctuate due to subject motion, then motion artifacts are generated in the data, but unclear criteria exist for determining which signal fluctuations are motion artifacts
Solution Approach 1:
The patent segments the detection into reflected light path and transmitted light path, allowing clear identification of motion artifacts in the reflected component. This segmentation makes it easy to detect and measure motion artifacts by focusing on the reflected light intensity variations rather than trying to identify them within the mixed transmitted signal.
Solution Approach 2:
The patent uses reflected light intensity measurement as an intermediary to identify and quantify motion artifacts. This intermediary measurement provides a clear proxy for subject motion, making it easy to detect and measure motion artifacts without directly observing probe movement or relying on ambiguous criteria.
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 enhances the reliability of brain function measurements by selectively removing directly reflected light components and reducing motion artifacts, thereby improving data accuracy and consistency.
Implementation Method 1
first polarizing means for linearly polarizing the light beam emitted from the light irradiation means in a first direction
Implementation Method 2
blocking means for blocking a component in the first direction of a reflected light beam that is generated as the light beam emitted from the first polarizing means is reflected by a hair of the test subject
Data Source
AI summary
Provided is a brain function measurement device capable of improving the reliability of brain function measurement using a simple configuration. The brain function measurement device includes light source probes LD2 and LD12 for irradiating the scalp of a test subject with light beams; linearly polarizing films P2 and P3 for polarizing the light beams emitted from the light source probes LD2 and LD12 in a first direction; a linearly polarizing film P1 for blocking components in the first direction of reflected light beams that are generated as the light beams emitted from the linearly polarizing film P2 and P3 are reflected by the hairs of the test subject; and a detection probe PD1 for detecting the intensity of a light beam that has passed through the linearly polarizing film P1.