Toothbrush Optical Sensing for Gum Bleeding Detection

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Solution Overview

Problem

Existing toothbrushing systems fail to effectively monitor and log gum bleeding, which is often ignored by individuals who do not feel pain, despite recommendations from the American Dental Association.

Innovation Solution

A toothbrush system equipped with a sensor that emits light at multiple wavelengths to detect hemoglobin in the oral cavity or toothpaste slurry during brushing, using intensity ratios to determine the presence of blood, and a processor to calculate and inform the user through an indicator or mobile app.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional toothbrush is used without monitoring capabilities, then the device complexity is low, but the ability to detect and monitor gum bleeding is lost

Engineering Contradiction:
Improvegum bleeding detectionVSAvoidtoothbrush system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical/visual detection methods with an optical sensor system that uses light absorption properties of hemoglobin to detect blood. The sensor emits light at multiple wavelengths and measures absorption to quantify blood presence, substituting the need for visual inspection or mechanical monitoring with an automated optical detection system.

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

Solution Approach 2:

The patent introduces an optical intermediary (light) that interacts with hemoglobin in the oral cavity to enable detection. The light serves as a mediator between the sensor and the target analyte (blood), allowing non-contact measurement through optical absorption properties without requiring direct contact or complex mechanical interaction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple light wavelengths are used to detect hemoglobin, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improvehemoglobin detectionVSAvoidsensor system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the optical parameters (wavelengths of light) to optimize hemoglobin detection. By using multiple specific wavelengths (including red and infrared where hemoglobin has characteristic absorption patterns), the system enhances measurement precision through spectral analysis. The processor analyzes the absorption spectrum at these specific wavelengths to accurately quantify blood presence.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The optical sensor system serves multiple functions: it detects the presence of blood, quantifies the amount of hemoglobin, and can potentially identify different types of oral cavity fluids. The same sensor hardware with multiple wavelengths provides comprehensive detection capabilities, making the system multi-functional for various oral health monitoring purposes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The system accurately detects and quantifies gum bleeding by analyzing light intensity ratios, providing users with real-time feedback to address potential oral health issues.

Implementation Method 1

the sensor is configured to emit first light at a first wavelength and second light at a second wavelength, receive reflected portions of the first light and the second light, and generate a first signal indicative of a first intensity of the reflected portion of the first light and a second signal indicative of a second intensity of the reflected portion of the second light

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

receive reflected portions of the first light and the second light

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4250314B1System for detecting blood in an oral cavity during toothbrushing
Publication Date: 2026.02.11 COLGATE PALMOLIVE CO
  • EP4250314B1 patent drawingFigure 1
  • EP4250314B1 patent drawingFigure 2
  • EP4250314B1 patent drawingFigure 3

AI summary

A system for detecting blood in an oral cavity during toothbrushing. The system may include a toothbrush having a sensor that is configured to emit first light at a first wavelength and second light at a second wavelength, receive reflected portions of the first and second light, and generate a first signal indicative of a first intensity of the reflected portion of the first light and a second signal indicative of a second intensity of the reflected portion of the second light. The system may include a processor operably coupled to the sensor, the processor being configured to receive the first and second signals and calculate a ratio of the first intensity to the second intensity to determine whether hemoglobin/blood is present in the oral cavity. The processor may be a part of the toothbrush or a part of a portable electronic device such as a smart phone.