Stress Estimation Models Using Data Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing devices for estimating stress levels from biological data face instability in estimation accuracy, particularly for unknown data.

Innovation Solution

A learning device and method that classify observed feature values to enhance the correlation with stress values, and train stress estimation models for each class to improve estimation accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If stress estimation is performed using biological data without classification, then the estimation process is simple, but the estimation accuracy for unknown data is unstable

Engineering Contradiction:
Improvestress estimation accuracyVSAvoidmodel training complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the stress estimation task into multiple specialized models, each trained on specific classes of biological data patterns. The classification means segments the input data into different classes based on correlation with stress values, and the learning means trains separate estimation models for each class. This segmentation allows each model to specialize in particular data patterns, improving overall estimation accuracy while maintaining manageable complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple stress estimation models are trained for respective classes, then the estimation accuracy improves, but the device complexity increases

Engineering Contradiction:
Improveestimation stabilityVSAvoidnumber of models
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the correlation threshold parameter that determines how data is classified into different classes. The classification means uses this adjustable parameter to control the granularity of data segmentation, allowing optimization between model complexity and estimation reliability. By changing this parameter, the system can adapt to different operational requirements without fundamentally altering the multi-model architecture.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If data is classified to increase correlation with stress values, then the estimation accuracy for unknown data improves, but the processing time increases

Engineering Contradiction:
Improveunknown data estimation accuracyVSAvoiddata processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing data classification and model selection before the actual stress estimation process. The classification means pre-processes the biological data to identify which class it belongs to, and the learning means pre-trains multiple estimation models for different classes during the learning phase. During operation, this preliminary classification allows the system to quickly route data to the appropriate pre-trained model, reducing real-time processing time while maintaining high accuracy for unknown data.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20250068698A1Learning device, stress estimation device, learning method, stress estimation method, and storage medium
Publication Date: 2025.02.27 NEC CORP
  • US20250068698A1 patent drawing
  • US20250068698A1 patent drawing
  • US20250068698A1 patent drawing

AI summary

A learning device 1X mainly includes a classifying means 14X and a learning means 17X. The classification means 14X classifies observed feature values of subjects so that an index representing a correlation between the observed feature values and a stress value becomes higher than the correlation before the classification, wherein the stress value is a correct answer corresponding to the observed feature values. The learning means 17X trains, based on the observed feature values and the stress value which is the correct answer, stress estimation models for respective classes divided at least by the classification, wherein the stress estimation models each estimates a relation between the observed feature values and the stress value.