Bevelled Foam Dressing for Leakage and Indentation Control

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Solution Overview

Problem

Venous leg ulcers with high exudation require wound dressings that manage exudate absorption while minimizing leakage and skin indentation risks under compression therapy, as existing foam dressings often lead to leakage and skin deterioration due to pressure and edge indentations.

Innovation Solution

A non-adhesive foam dressing with bevelled edges of higher density than the central part, where the edge portion has a density of 600-900 kg/m³ and the central portion 150-200 kg/m³, and a backing layer extending to the wound-contacting surface, reducing leakage and indentation risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the foam density at the edges is increased to prevent leakage of wound exudate, then the leakage risk is reduced, but the risk of indentations in the leg is enhanced

Engineering Contradiction:
Improveleakage preventionVSAvoidskin indentation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The foam dressing is designed with non-uniform density distribution: the edge portions have higher density (600-900 kg/m³) to prevent leakage, while the central portion has lower density (150-200 kg/m³) to reduce pressure on the skin and prevent indentations. This local differentiation of material properties resolves the contradiction between leakage prevention and skin protection.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a non-adhesive foam dressing is used to avoid skin deterioration, then adhesive-related skin damage is prevented, but the risk of exudate leakage from the edges increases

Engineering Contradiction:
Improveskin deteriorationVSAvoidexudate containment
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The non-adhesive foam dressing incorporates edge portions with higher density (600-900 kg/m³) that provide improved exudate containment at the boundaries, while maintaining the non-adhesive property across the entire dressing to prevent skin deterioration. The localized density enhancement at edges compensates for the lack of adhesive sealing.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If the foam dressing thickness is increased to improve absorption capacity, then the absorption capacity is enhanced, but the pressure from compression therapy causes more pronounced indentations

Engineering Contradiction:
Improveabsorption capacityVSAvoidindentation severity
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The foam dressing uses lower density (150-200 kg/m³) in the central portion where compression pressure is applied, which reduces the severity of indentations. The edge portions have higher density (600-900 kg/m³) to prevent exudate leakage. This density differentiation allows the dressing to maintain adequate absorption capacity while minimizing indentation-related skin damage under compression therapy.

Inventive Principle:
Principle #3Local quality

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 bevelled edge design minimizes leakage and skin indentations by creating a barrier for wound exudate and optimizing absorption capacity, preventing exudate from leaking through the edges and reducing skin pressure, thus enhancing wound healing.

Implementation Method 1

the absorbent layer comprising polymeric foam

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

the absorption capacity of the foam may reach its maximum

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP1931289B2Bevelled foam
Publication Date: 2023.03.08 COLOPLAST AS
  • EP1931289B2 patent drawingFigure 1~3G
  • EP1931289B2 patent drawingFigure 4~7
  • EP1931289B2 patent drawingFigure 8~10

AI summary

The invention relates to a foam dressing with a bevelled edge and where the density at the edge is higher than the density at the central part of the foam. The high density at the edges causes gel blocking of the wound exudate thereby preventing leakage of exudate through the edges. In a preferred embodiment the foam dressing is non-adhesive. The foam dressing may have a water-impervious backing layer, which extends all the way over the top of the dressing and down to the wound-contacting surface. The wound dressing is particularly useful in treatment of venous ulcers in connection with compression bandages, as the bevelling of the edges markedly reduces the indentations in the leg following use of this dressing when compared to a dressing with straight edges.