3D-Knitted Wound Dressing for Exudate Storage and Open Flow

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Solution Overview

Problem

Existing wound dressings for negative pressure wound therapy face issues with limited exudate capacity, blockages due to solid material accumulation, and vulnerability to compressive and shear forces, which can disrupt wound healing.

Innovation Solution

A wound dressing with a 3D knitted transmission layer, absorbent layer, and moisture vapor permeable cover layer, designed to collect and store exudate, manage fluid flow, and absorb forces, maintaining an open flow path and preventing blockages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wound dressing is used to store extracted wound exudate, then the dressing acts as a buffer to prevent compression or shear forces from harming the wound, but the dressing has limited capacity for fluid uptake before a dressing change is required

Engineering Contradiction:

Improveprotection from compression or shear forcesVSAvoidfluid uptake capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The wound dressing is divided into multiple functional layers: a fluid-permeable layer for force buffering, an absorbent layer for exudate storage, and a moisture vapor permeable cover layer for vapor transmission. This segmentation allows each layer to specialize in one function, resolving the contradiction between protection and fluid capacity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces moisture vapor permeability as a new dimension of fluid management. By allowing moisture vapor to escape through the cover layer while the absorbent layer stores liquid exudate, the system effectively increases total fluid handling capacity beyond what a single layer could provide.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If a liquid impermeable moisture vapor permeable cover layer is used, then liquid can constantly evaporate away from the top of the dressing, but solid material build-up can lead to blockages in the flowpath

Engineering Contradiction:

Improveliquid evaporation rateVSAvoidflowpath blockage prevention

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

Different regions of the dressing have different properties: the cover layer is moisture vapor permeable for evaporation, the absorbent layer has high liquid absorption capacity to prevent solid concentration, and the fluid-permeable layer maintains open flow paths. This local differentiation resolves the contradiction between evaporation and blockage prevention.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The absorbent layer acts as an intermediary between the wound exudate and the moisture vapor permeable cover layer. It absorbs liquid exudate and prevents solid material from reaching the cover layer surface where it could form blockages, while still allowing moisture vapor to pass through.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If a separate canister is provided for storage of wound exudate, then exudate can be stored for later disposal, but the canister is costly and bulky and prone to failure

Engineering Contradiction:

Improveexudate storage capacityVSAvoidcanister structure

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The storage function previously separated into a distinct canister is merged into the wound dressing itself. The absorbent layer within the dressing provides exudate storage capacity, eliminating the need for a separate canister and its associated complexity, cost, and failure points.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The wound dressing is designed to perform multiple functions: it protects from mechanical forces, absorbs and stores exudate, allows moisture vapor evaporation, and prevents blockages. This multi-functionality eliminates the need for separate specialized components like canisters.

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 dressing extends the therapy duration by absorbing exudate, reduces blockages, and protects the wound from external forces, ensuring continuous negative pressure application and enhanced healing.

Implementation Method 1

an absorbent layer for absorbing wound exudate, the absorbent layer overlying the transmission layer

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

The moisture vapor permeability of this covering layer is selected so that liquid can constantly evaporate away from the top of the dressing

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

a transmission layer comprising a 3D knitted or fabric material configured to remain open upon application of negative pressure to the wound dressing

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Data Source

PatentUS12414877B2Wound dressing and method of use

Publication Date: 2025.09.16 SMITH & NEPHEW PLC

AI summary

A system, method, and apparatus are disclosed for dressing a wound. The apparatus comprises a liquid and gas permeable transmission layer, an absorbent layer for absorbing wound exudate, the absorbent layer overlying the transmission layer, a gas impermeable cover layer overlying the absorbent layer and comprising a first orifice, wherein the cover layer is moisture vapor permeable.