Facial Skin Temperature Brain Activity Estimation

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Solution Overview

Problem

Current methods for estimating human brain activity, such as electroencephalography, functional magnetic resonance imaging, and near infrared spectroscopy, are cumbersome and costly, requiring pretreatment of electrodes and restrictive measurement conditions, making it difficult to obtain useful information about emotional and physical states.

Innovation Solution

A device that estimates brain activity using time-series facial skin temperature and facial blood circulation volume data, acquired without the need for electroencephalogram electrodes or sensors, by decomposing the data into components using singular value decomposition and analyzing correlations with brain resting and activated times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electroencephalography, fMRI, or NIRS methods are used to estimate brain activity, then measurement precision is improved, but device complexity and ease of operation deteriorate due to electrode pretreatment and restrictive measurement conditions

Engineering Contradiction:
Improvebrain activity estimation accuracyVSAvoidoperational simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces complex mechanical sensor systems (electrode attachments, probe applications) with optical imaging systems that capture facial skin temperature and blood circulation volume data. This substitution eliminates the need for physical contact and pretreatment while maintaining measurement capability through non-invasive thermal and colorimetric detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a simplified proxy measurement system that captures brain activity information indirectly through facial physiological changes (temperature and blood circulation) rather than directly measuring neural electrical activity. This copying approach uses easily obtainable facial images and temperature data as substitutes for complex direct brain measurements.

Inventive Principle:
Principle #26Copying

2Measurement precision

If electroencephalography, fMRI, or NIRS methods are used to estimate brain activity, then measurement precision is improved, but device complexity worsens due to complex equipment requirements

Engineering Contradiction:
Improvebrain activity estimation accuracyVSAvoidequipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical sensor systems (electrode attachments, probe applications) with optical imaging systems that capture facial skin temperature and blood circulation volume data. This substitution eliminates the need for physical contact and pretreatment while maintaining measurement capability through non-invasive thermal and colorimetric detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a simplified proxy measurement system that captures brain activity information indirectly through facial physiological changes (temperature and blood circulation) rather than directly measuring neural electrical activity. This copying approach uses easily obtainable facial images and temperature data as substitutes for complex direct brain measurements.

Inventive Principle:
Principle #26Copying

3Measurement precision

If traditional brain activity measurement methods are used, then measurement precision is improved, but loss of time increases due to preparation work and restrictive measurement conditions

Engineering Contradiction:
Improvebrain activity estimation accuracyVSAvoidpreparation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary data processing by decomposing facial skin temperature and blood circulation volume data into multiple components using singular value decomposition before analysis. This preliminary decomposition separates signal components related to brain activity from noise and other physiological variations, enabling faster and more accurate measurement without requiring extensive preparation time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex mechanical sensor systems (electrode attachments, probe applications) with optical imaging systems that capture facial skin temperature and blood circulation volume data. This substitution eliminates the need for physical contact and pretreatment while maintaining measurement capability through non-invasive thermal and colorimetric detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 easy and accurate estimation of brain activity, reducing subject burden and costs, while providing valid information on emotional and physical states without the need for complex equipment or restrictive measurement conditions.

Implementation Method 1

facial skin temperature acquisition means for acquiring time-series facial skin temperature data including position data of a detection site on the basis of photographic image data of the facial surface of the subject

Methodology Applied
Scientific EffectThermal radiation detection: Thermography

Implementation Method 2

decomposes the face skin temperature data into a plurality of components; extracts a component, the waveform amplitude of which correlates with a change at a time of stability or activation of the brain

Methodology Applied
Scientific EffectSingular value decomposition:

Implementation Method 3

The brain has a mechanism called the selective brain cooling system whereby the brain is cooled independently of body temperature. The selective brain cooling system is known to discharge heat generated by brain activity using the areas around the forehead and the paranasal sinuses.

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP3363352B1Useful information presentation device
Publication Date: 2020.11.25 DAIKIN INDUSTRIES LTD
  • EP3363352B1 patent drawingFigure 1(a)~1(b)
  • EP3363352B1 patent drawingFigure 2(a)~2(b)
  • EP3363352B1 patent drawingFigure 3(a)~3(b)

AI summary

A useful information presentation device (300, 301, 302) includes facial skin temperature acquisition means (20) and/or image data acquisition means (120), brain activity estimation means (30, 130), and useful information presentation means (200). The facial skin temperature acquisition means (20) acquire facial skin temperature data in time-series. The image data acquisition means (120) acquire photographic image data of the facial surface in time-series. A plurality of components is obtained by decomposing the facial skin temperature data and/or the facial blood circulation volume data by singular value decomposition, principal component analysis, or independent component analysis. The brain activity estimation means (30, 130) estimate the brain activity of the subject on the basis of this plurality of components. The useful information presentation means (200) present useful information related to an emotional or physical state on the basis of the brain activity of the subject estimated by the brain activity estimation means (30, 130).