Brainwave-Based Pain Estimation Using Sigmoid Classification

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Solution Overview

Problem

Current methods for objectively estimating pain using brainwaves face challenges due to subjective pain declaration and variability among individuals, making accurate and objective pain classification difficult.

Innovation Solution

A pain estimation apparatus and method that utilize a sigmoid function to classify pain based on brainwave data, allowing for objective and accurate estimation of pain levels without relying on subjective pain declaration, by stimulating individuals with varying intensities and analyzing brainwave amplitudes to generate a pain classifier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If subjective pain declaration is used for pain estimation, then individual pain perception can be captured, but objectivity and accuracy of pain evaluation deteriorates due to variability among individuals

Engineering Contradiction:
Improvepain estimation accuracyVSAvoidsubjective pain declaration
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the mechanical/subjective system of pain declaration with a physiological measurement system using brainwave signals. EEG-based objective pain evaluation substitutes subjective self-reporting, eliminating individual variability in pain expression while maintaining measurement accuracy through physiological indicators.

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

Solution Approach 2:

The patent introduces brainwave signals as an intermediary between the pain stimulus and evaluation. Instead of directly measuring subjective pain perception, the system uses EEG signals as a mediator that objectively reflects pain states, enabling accurate pain estimation without relying on subjective declaration.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If brainwave data from multiple individuals with different pain levels is used as reference data, then comprehensive pain coverage is achieved, but estimation accuracy deteriorates due to individual variability in brainwave characteristics

Engineering Contradiction:
Improvepain level coverageVSAvoidpain estimation accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary individual calibration by measuring brainwave responses at multiple stimulation levels before actual pain evaluation. This preliminary action creates a personalized reference pattern for each individual, allowing the system to accommodate different pain thresholds while maintaining estimation accuracy through subject-specific baselines.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by customizing the evaluation approach for each individual rather than using a universal reference. The system adjusts reference data and evaluation criteria locally for each subject based on their unique brainwave characteristics, enabling both comprehensive pain level coverage and high estimation accuracy simultaneously.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If strong pain stimulation is applied to establish reference data, then accurate pain classification threshold is obtained, but harmful effects increase due to inflicting strong pain on subjects

Engineering Contradiction:
Improvepain classification accuracyVSAvoidpain infiction to subject
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses partial action by applying multiple levels of stimulation including zero or mild stimulation instead of requiring strong pain induction. By measuring brainwave responses across a range from no stimulation to mild stimulation, the system can accurately classify pain levels without inflicting strong pain, achieving the necessary reference data through progressive rather than extreme stimulation.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4137042B1Classification of pain based on brain wave data
Publication Date: 2024.05.22 OSAKA UNIVERSITY
  • EP4137042B1 patent drawingFigure 1~2
  • EP4137042B1 patent drawingFigure 3~4
  • EP4137042B1 patent drawingFigure 5~6

AI summary

Provided is a pain estimating device with which it is possible to estimate objectively and accurately pain being experienced by a subject. A pain estimating device 110 estimates the magnitude of pain being experienced by a subject, on the basis of brainwaves of the subject, and is provided with: a measurement unit 111 which acquires a plurality of items of brainwave data or analysis data thereof by measuring brainwaves from the subject a plurality of times; and an estimation unit 112 which estimates the relative magnitude of the pain being experienced when the brainwave measurements were conducted a plurality of times, from the plurality of items of brainwave data or the analysis data thereof (for example the amplitude), on the basis of the linearity of a relationship between the brainwave data or the analysis data thereof (for example the amplitude) and the pain. The present invention also provides a pain estimating method and device with which it is possible to estimate objectively and accurately pain being experienced by a subject, and to classify simply the quality and quantity thereof. The present invention also provides a method for generating a pain classification value for classifying pain being experienced by the subject, on the basis of brainwaves of the subject.