Moisture Indicator for Wound Dressings Using pH-Dependent Color Change

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Solution Overview

Problem

Current wound dressings lack reliable and sensitive moisture detection methods, with existing indicators being difficult to perceive and potentially fostering bacterial colonization due to excess fluid accumulation.

Innovation Solution

A wound dressing with a pH-dependent moisture indicator that utilizes a soluble composition to release hydrogen or hydroxide ions, causing a color change in a pH indicator, providing a more sensitive and perceivable visual signal for moisture levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pH indicator is used to detect wound exudate, then moisture detection sensitivity is improved, but the visual signal is difficult to perceive

Engineering Contradiction:
Improvemoisture detection sensitivityVSAvoidvisual signal perception
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent changes the pH parameter of the wound exudate by introducing a soluble composition that releases hydrogen or hydroxide ions upon dissolution. This pH change amplifies the color change of the pH indicator, making the visual signal more perceptible while maintaining high moisture detection sensitivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes color changes as the primary indication mechanism. A pH indicator is employed that changes color in response to pH changes caused by the soluble composition. The color change is amplified by the pH modification, providing a clear and easily perceptible visual signal that resolves the perception difficulty

Inventive Principle:
Principle #32Color changes

2Measurement precision

If an impermeable outer covering with blister indicator is used, then moisture leakage detection is improved, but bacterial colonization risk increases

Engineering Contradiction:
Improvemoisture leakage detectionVSAvoidbacterial colonization risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent removes the impermeable outer covering and blister formation mechanism from the dressing system. Instead, it uses a chemical indication mechanism (pH indicator with soluble composition) that detects moisture through pH changes, eliminating the fluid accumulation that fosters bacterial growth while maintaining detection capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potentially harmful wound exudate into a useful indicator. The exudate itself, when it dissolves the soluble composition and changes pH, becomes the trigger for the color change indication, turning a potential bacterial growth medium into a beneficial detection mechanism

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 solution provides an amplified and easily readable color change, indicating optimal moisture levels, reducing the risk of desiccation or maceration and enhancing wound healing monitoring.

Implementation Method 1

a second composition which dissolves upon contact with a wound exudate to release hydrogen or hydroxide ions

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 2

release hydrogen or hydroxide ions into the wound exudate

Methodology Applied
Scientific EffectIon release: Electrolysis

Implementation Method 3

a first composition which has a first colour and which changes to a second colour in response to a change in pH

Methodology Applied
Scientific EffectpH-dependent color change: Photochromism

Data Source

PatentEP3004854B1Moisture indicating system
Publication Date: 2020.07.08 SMITH & NEPHEW PLC
  • EP3004854B1 patent drawingFigure 1A~1B
  • EP3004854B1 patent drawingFigure 2A~2B
  • EP3004854B1 patent drawingFigure 3A~3B

AI summary

Device which indicates wound exudate loading within a wound dressing.