Skin Collagen Thickness Measurement Using 3D Surface Normalization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for measuring skin collagen thickness are limited by the need for strict calibration procedures, which restrict their application to small areas of skin with flat surface geometry, making it difficult to accurately measure collagen thickness over larger areas or those with non-flat geometries like the face.

Innovation Solution

An apparatus and method that use a digital camera, lighting calibration data, and 3D surface modeling to normalize light intensity variations due to surface geometry, allowing for the measurement of collagen thickness by processing infra-red and color channel data to account for illumination and orientation changes, enabling collagen thickness measurement over wider areas with non-flat surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strict calibration procedures are used to measure collagen thickness, then measurement precision is improved, but the method is limited to small areas with flat surface geometry

Engineering Contradiction:
Improvecollagen thickness measurement accuracyVSAvoidapplicability to different skin areas and geometries
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the measurement parameter from absolute light intensity to light intensity ratios. By using ratios of light intensity at different wavelengths or positions, the method eliminates the need for strict calibration while maintaining measurement accuracy. This parameter transformation allows the system to work on various skin areas with different geometries without requiring flat surfaces or precise calibration procedures.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If calibration procedures are implemented, then measurement accuracy is improved, but device complexity and operational difficulty increase

Engineering Contradiction:
Improvecollagen thickness measurement accuracyVSAvoidcalibration procedure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the calibration procedure from the measurement system. By using ratio-based measurements, the method eliminates the need for separate calibration steps and calibration references. This extraction simplifies the overall system operation, making it easier to use while maintaining measurement accuracy across different skin areas and geometries.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If calibration is performed on small flat areas, then measurement precision is improved, but the measurable area size is limited

Engineering Contradiction:
Improvecollagen thickness measurement accuracyVSAvoidmeasurable skin area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent applies segmentation by measuring collagen thickness at multiple discrete points across the skin surface and then integrating or averaging these measurements. This allows the system to measure large areas by combining data from multiple smaller measurement points, maintaining precision while expanding the measurable area beyond the limitations of single-point calibration methods.

Inventive Principle:
Principle #1Segmentation

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 accurate measurement of skin collagen thickness over larger areas, including the face, by normalizing light intensity variations, thus overcoming the limitations of previous techniques and providing a more comprehensive analysis of skin histology.

Implementation Method 1

a digital camera to obtain image data of an area of skin when the area of skin is illuminated by light

Methodology Applied
Scientific EffectLight remittance: Reflection

Implementation Method 2

the Kubelka-Munk theory is sufficient to model light transport within skin

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 3

a model of the scattering and absorption characteristics of the skin

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP2050385B1Method and apparatus for measuring collagen thickness
Publication Date: 2011.04.27 BIOCOMPATIBLES UK LTD
  • EP2050385B1 patent drawingFigure 1
  • EP2050385B1 patent drawingFigure 2
  • EP2050385B1 patent drawingFigure 3

AI summary

A camera (1) is provided which is operable to obtain a RGB and infra-red image of an area of illuminated skin (2). The obtained image is then passed to a computer (8) which determines the manner in which light returned by points on the surface of the illuminated area of skin (2) appearing in the obtained image varies due to variations in lighting intensity and surface geometry. The infra-red channel of the obtained image is then normalized on the basis of the determined variations and a measurement of collagen thickness can then be determined utilizing the processed infra-red channel of the obtained image. The determination of variations in intensities of light returned by points on the surface of the illuminated area of skin (2) can be achieved by processing an obtained image to generate a 3-D model of the surface being imaged and using the 3-D model to select and process pre-stored lighting level data.