Scalp Type Classification Using Sebum and Humidity Sensing

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Solution Overview

Problem

Existing methods for determining scalp type are subjective, inconvenient, and inaccurate, often relying on visual assessment and user input, which can lead to unsuitable hair and scalp care product recommendations.

Innovation Solution

A method using biophysical measurements of humidity and sebum levels on the scalp, categorized into five distinct groups, each associated with specific hair and scalp care product recommendations, utilizing a portable device and processor for objective assessment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple indicators (sebum content, blood flow, temperature, oxygen saturation) are measured to accurately determine scalp type, then classification accuracy is improved, but device complexity and measurement time increase

Engineering Contradiction:
Improvescalp type classification accuracyVSAvoidmeasurement device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple measurement functions (sebum content measurement, blood flow measurement, temperature measurement, and oxygen saturation measurement) into a single integrated scalp analysis device. This merging approach allows simultaneous acquisition of multiple indicators through coordinated sensors, improving classification accuracy while managing device complexity through unified control architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The analysis device is designed with multi-functionality to perform diverse measurements (sebum, blood flow, temperature, oxygen saturation) using a single device platform. This universal design enables comprehensive scalp type determination without requiring separate specialized devices for each parameter, balancing measurement precision with device complexity.

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

2Measurement precision

If multiple indicators are measured to accurately determine scalp type, then classification accuracy is improved, but measurement time increases

Engineering Contradiction:
Improvescalp type classification accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The device performs multiple measurements (sebum content, blood flow, temperature, oxygen saturation) in a continuous and coordinated manner rather than sequentially. The sensors operate simultaneously to capture all required indicators during a single scalp analysis session, maintaining high classification accuracy while minimizing total measurement time through parallel data acquisition.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If sebum content measurement is performed frequently to track scalp condition changes, then monitoring accuracy is improved, but user discomfort and device wear increase

Engineering Contradiction:
Improvescalp condition monitoring accuracyVSAvoiduser discomfort
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical contact-based measurement methods with optical sensing technology for sebum content measurement. The optical sensors detect sebum levels through non-contact or minimal-contact means, enabling frequent monitoring to improve accuracy while significantly reducing user discomfort and avoiding device wear associated with mechanical contact methods.

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

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

Provides a simple, objective, and convenient method for determining scalp type, enabling personalized and accurate product recommendations based on biophysical parameters, reducing subjectivity and improving scalp and hair care outcomes.

Implementation Method 1

amount of sebum secreted by the scalp

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Implementation Method 2

amount of sebum secreted by the scalp

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 3

blood flow in the scalp

Methodology Applied
Scientific EffectPhotoplethysmography: Photoelectric Effect

Implementation Method 4

blood flow in the scalp

Methodology Applied
Scientific EffectLaser Doppler vibrometry: Laser Doppler Velocimetry

Implementation Method 5

temperature of the scalp

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 6

temperature of the scalp

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 7

oxygen saturation in the scalp

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Data Source

PatentEP4171376B1Method for determining a scalp type of a user
Publication Date: 2026.05.06 HENKEL KGAA
  • EP4171376B1 patent drawingFigure 1
  • EP4171376B1 patent drawingFigure 2
  • EP4171376B1 patent drawingFigure 3

AI summary

A method (10) for determining a scalp (21) type of a user (20), the method (10) comprising: obtaining a value indicative of a humidity level (111) of a region of the scalp (21) of the user (20) and a value indicative of a sebum level (112) in the region of the scalp (21) of the user (20), comparing a set comprising both values to reference ranges of scalp humidity levels (111) and sebum levels (112), the reference ranges forming at least five scalp groups (131-135), each scalp group (131-135) being associated with a humidity level (111) range and a sebum level (112) range, and with a corresponding category of skin and/or hair care compositions and/or skin and/or hair care treatments compatible with humidity level (111) range and sebum level (112) range, identifying, based on the comparison, the scalp (21) type of the user (20) and outputting the identified scalp (21) type.