Pulse Wave Chaos Analysis for Comfortable Environment Control

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Solution Overview

Problem

Existing environment control systems struggle to accurately infer and maintain a comfortable feeling for users due to reliance on invasive equipment, individual variability, and the need for long-term biological data collection, which limits real-time stimulus adjustment.

Innovation Solution

An environment control device that acquires time-series biological data, performs chaos analysis to calculate parameters like the maximum Lyapunov exponent and wave height, and uses these to infer a user's thermal sensation, allowing for real-time stimulus control to enhance comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If brain wave analysis is used to infer comfortable feeling, then measurement precision is improved, but device complexity and ease of operation deteriorate due to large-scale equipment requirements and movement restrictions

Engineering Contradiction:

Improvecomfortable feeling inference accuracyVSAvoidequipment complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential physiological information needed for comfortable feeling inference from complex brain wave analysis by using simpler pulse wave signals instead. This extraction allows maintaining inference accuracy while eliminating the need for complex large-scale equipment and movement restrictions associated with brain wave analysis.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical and complex brain wave measurement system with a simpler optical or electrical pulse wave measurement system. This substitution maintains the ability to infer comfortable feeling while dramatically reducing device complexity and improving ease of operation through minimal user constraints.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If brain wave analysis is used to infer comfortable feeling, then measurement precision is improved, but ease of operation deteriorates due to movement restrictions

Engineering Contradiction:

Improvecomfortable feeling inference accuracyVSAvoiduser convenience

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If chaos analysis with maximum Lyapunov exponent is used, then measurement precision is improved, but calculation complexity increases

Engineering Contradiction:

Improvethermal sensation inference accuracyVSAvoidcalculation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by pre-calculating and storing the maximum Lyapunov exponent values and their corresponding thermal sensation mappings during a calibration phase. This allows the system to quickly reference pre-computed chaos analysis results rather than performing complex real-time calculations, thereby maintaining high measurement precision while reducing operational calculation complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies partial action by using only the most critical chaos analysis parameter (maximum Lyapunov exponent) rather than computing the full spectrum of chaos theory metrics. This selective approach maintains sufficient measurement precision for thermal sensation inference while significantly reducing calculation complexity and processing requirements.

Inventive Principle:

Principle #16Partial or excessive action

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 and accurate maintenance of a comfortable state by eliminating the need for invasive equipment and accounting for individual variability, allowing for immediate adjustments to environmental stimuli.

Implementation Method 1

a blood flow discharged from the heart and delivered to peripheral fingertips comes under a significant influence of physiological conditions, such as a change in property of a heart rate, hemodynamics, and an arteriolovenular system, and such a change is reflected on the waveform of the pulse wave

Methodology Applied

Scientific EffectPulse wave:

Implementation Method 2

a parameter about the biological information is calculated through chaos analysis of the time-series data

Methodology Applied

Scientific EffectChaos analysis:

Data Source

PatentUS8140191B2Environment control device, environment control method, environment control program, and computer-readable recording medium containing the environment control program

Publication Date: 2012.03.20 PANASONIC HOLDINGS CORP

AI summary

An environment control device, an environment control method, an environment control program, and a computer-readable recording medium containing the environment control program for enabling the user to actually have a comfortable feeling in a reliable manner and further to maintain such a comfortable state, are provided. A biological information measuring portion acquires time-series data of the biological information of the user. A chaos analysis portion calculates a parameter about the biological information through chaos analysis of the time-series data acquired by the biological information measuring portion. A state inferring portion infers a comfortable feeling of the user on the basis of the parameter calculated by the chaos analysis portion. A device control portion controls generation of a stimulus to be given to the user on the basis of the result of inference made by the state inferring portion.