Wearable Wearing-State Detection Using Multi-Wavelength Reflected Light

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Solution Overview

Problem

Existing wearable device detection technologies suffer from high error rates and high power consumption due to inaccurate determination of wearing state, often caused by light reflection from non-skin tissues and continuous monitoring of heart rate signals.

Innovation Solution

A method and module for detecting wearing state using at least two types of light signals with different wavelengths, where the light emitter emits light signals according to a preset emission period, and the light receiver receives and processes reflected light to determine the wearing state based on change trends and signal differences, reducing interference and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple optical threshold method is used to detect wearing state by monitoring reflected light, then the device complexity is reduced, but the measurement precision deteriorates due to large error rates and wrong determination when non-skin tissue approaches

Engineering Contradiction:
Improvedetection method complexityVSAvoidwearing state detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses multiple light wavelengths (e.g., 650nm red light and 530nm green light) instead of a single wavelength to detect wearing state. By analyzing the differential absorption characteristics of skin tissue at different wavelengths, the system achieves more accurate detection while maintaining relatively simple device structure. The processor compares reflected light intensities at multiple wavelengths to distinguish skin from non-skin surfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary processing layer where the processor analyzes the relationship between reflected light intensities at different wavelengths. Instead of directly thresholding single-wavelength signals, the system computes a differential metric that serves as an intermediary indicator for wearing state, thereby improving precision without significantly increasing hardware complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If continuous heart rate signal monitoring is used to determine wearing state, then the reliability of detection is improved, but the energy consumption increases significantly

Engineering Contradiction:
Improvedetection reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of continuous monitoring, the patent implements periodic wearing state detection using light reflection analysis. The system periodically emits light signals at multiple wavelengths and analyzes the reflected intensities to determine wearing state. This periodic operation maintains detection reliability while significantly reducing power consumption compared to continuous heart rate monitoring.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts the essential wearing state information from optical reflection characteristics alone, separating this detection function from continuous physiological signal monitoring. By taking out the wearing detection task from the continuous heart rate monitoring system, the patent achieves reliable detection with minimal energy expenditure, as the light emission and analysis can be performed intermittently.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If multiple light wavelengths are used to improve detection accuracy, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improvewearing state detection accuracyVSAvoidoptical system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple light wavelengths from a single light emitter (e.g., multiple LEDs or a multi-wavelength source) and uses a single photodetector to receive reflected light. The processor then separates and analyzes the different wavelength components by comparing their reflected intensities. This merging approach achieves multi-wavelength detection without requiring separate optical paths for each wavelength, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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

Accurately determines the wearing state of a wearable device with reduced power consumption by utilizing the optical characteristics of human tissue, providing simple and accurate detection through dynamic analysis of reflected light trends.

Implementation Method 1

controlling the light receiver to receive reflected light corresponding to the at least two types of light signals reflected by the user

Methodology Applied
Scientific EffectOptical reflection: Reflection

Data Source

PatentEP3542711B1Wearing state detection method, and detection module and wearable device thereof
Publication Date: 2025.12.10 SHENZHEN GOODIX TECH CO LTD
  • EP3542711B1 patent drawingFigure 1~2
  • EP3542711B1 patent drawingFigure 3~4
  • EP3542711B1 patent drawingFigure 5~7

AI summary

The present disclosure relates to intelligent wearable devices, and provides a method and a module for detecting a wearing state, and a wearable device thereof. The method for detecting a wearing state is applied to the wearable device, and the wearable device includes a light emitter and a light receiver. The detection method includes: controlling the light emitter to emit at least two types of light signals to a user; controlling the light receiver to receive reflected light corresponding to the at least two types of light signals reflected by the user; and determining the wearing state of the wearable device according to change trends of at least two types of the received reflected light. The wearing state of the wearable device is determined more accurately by adopting embodiments of the present disclosure.