NPWT Dressing Liquid Spreading Layer for Longer Wear Time

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Solution Overview

Problem

Portable NPWT systems face issues with dressing saturation due to excessive wound exudate, leading to reduced wear time and instability, as the dressing needs frequent replacement.

Innovation Solution

Incorporation of a liquid spreading layer between the absorbent structure and backing layer, along with a balanced distribution of superabsorbent particles, to efficiently manage and distribute exudate, ensuring effective transfer to a remote fluid collection means while maintaining wound dryness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a portable NPWT device with a smaller pump is used, then the device portability is improved, but the capacity to handle wound exudate is reduced

Engineering Contradiction:

Improvedevice portabilityVSAvoidwound exudate handling capacity

Core Design Contradiction:

Weight of moving objectVSQuantity of substance

Solution Approach 1:

The absorbent structure is divided into multiple layers including a hydrophilic layer, a hydrophobic layer, and a liquid spreading layer. This segmentation allows different layers to perform specific functions: the hydrophilic layer initially absorbs exudate, the liquid spreading layer distributes it evenly, and the hydrophobic layer prevents saturation, collectively enhancing the overall exudate handling capacity of the portable device.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The absorbent structure uses composite materials combining hydrophilic polymers, hydrophobic polymers, and liquid spreading agents in a multi-layer configuration. This composite structure leverages the complementary properties of different materials to achieve both high exudate absorption capacity and efficient distribution, compensating for the limited pump capacity in portable devices.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If the dressing absorbs a large amount of wound exudate, then the wound exudate removal is improved, but the wear time of the dressing is reduced due to saturation

Engineering Contradiction:

Improvewound exudate removalVSAvoiddressing wear time

Core Design Contradiction:

Quantity of substanceVSDuration of action of moving object

Solution Approach 1:

The liquid spreading layer is pre-configured in the absorbent structure to distribute exudate evenly across the absorbent layers before saturation occurs. This preliminary distribution action prevents localized saturation, allowing the dressing to maintain absorption capacity throughout its wear time and extend the duration before replacement is needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The absorbent structure dynamically manages exudate flow through its multi-layer design, where the liquid spreading layer continuously redistributes absorbed fluid to unsaturated regions. This dynamic redistribution mechanism allows the dressing to handle large amounts of exudate while maintaining operational effectiveness throughout an extended wear period.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If the dressing is disconnected from the negative pressure source, then the portability and ease of use is improved, but exudate may flow back towards the wound site

Engineering Contradiction:

Improveportability and ease of useVSAvoidexudate backflow

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The liquid spreading layer acts as an intermediary barrier between the absorbent structure and the external environment. When the dressing is disconnected from the negative pressure source, this layer prevents direct backflow of exudate towards the wound site by distributing and containing the fluid within the absorbent structure, thus protecting the wound while maintaining portability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 extends the wear time of the dressing by efficiently managing exudate distribution and transfer, reducing the frequency of replacements and maintaining therapeutic effectiveness.

Implementation Method 1

The liquid spreading layer improves the spreading and distribution of wound exudate within the dressing

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

an absorbent structure arranged between the backing layer and the adhesive skin contact layer

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

Negative pressure wound therapy (NPWT) is a technique that promotes healing of e.g. surgical, acute and chronic wounds by the application of a sub-atmospheric pressure to the wound, using a negative pressure pump

Methodology Applied

Scientific EffectNegative pressure: Pressure Gradient

Data Source

PatentEP4157177B1A negative pressure wound therapy (NPWT) dressing

Publication Date: 2025.12.03 MOLNLYCKE HEALTH CARE AB

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AI summary

The present disclosure generally relates to a negative wound therapy (NPWT) dressing (100) comprising a backing layer (101), an adhesive skin contact layer (102); the adhesive skin contact layer (102) being configured to detachably adhere the dressing (100) to a dermal surface, wherein the backing layer (101) comprises a coupling member (104); the coupling member (104) comprising a tubing (105) configured to connect the dressing (100) to a negative pressure source and to a remote fluid collection means.