NPWT Exhaust Blockage Detection via Dual Pressure Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current negative pressure wound therapy (NPWT) systems face challenges in effectively managing fluid aspiration and detecting blockages, which can impede the healing process and require additional interventions.

Innovation Solution

The proposed NPWT system incorporates a wound dressing with integrated components, including a source of negative pressure, a pressure sensor, and a controller. This system is designed to absorb fluid, aspirate it under negative pressure, and feature a vent for gas release, with a pressure sensor and controller working together to indicate blockages and maintain optimal therapy settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a vent is added to allow gas to flow outside the system, then gas aspiration is improved, but the risk of vent blockage increases which can impede therapy

Engineering Contradiction:
Improvegas aspiration efficiencyVSAvoidvent blockage risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The pressure sensor continuously monitors pressure in the fluid flow path and provides feedback to the controller. When the vent becomes blocked, pressure changes are detected and transmitted to the controller, which then provides feedback indication to alert the user of the blockage condition, enabling timely intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The pressure sensor acts as an intermediary between the vent system and the controller. It detects pressure changes caused by vent blockage and translates them into signals that the controller can process and communicate to the user, serving as a mediator that bridges the physical blockage condition and the user interface.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If continuous monitoring is implemented to detect blockages, then therapy reliability is improved, but device complexity increases due to additional sensors and controllers

Engineering Contradiction:
Improveblockage detection capabilityVSAvoidsystem component count
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressure sensor serves multiple functions: it monitors pressure in the fluid flow path, detects vent blockage conditions, and provides data for controlling the negative pressure source. This multi-functionality reduces the need for separate dedicated blockage detection components, thereby limiting the increase in device complexity while maintaining reliable monitoring.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its existing pressure measurement infrastructure to simultaneously detect blockages without requiring entirely separate detection mechanisms. The same pressure sensor used for therapy control also serves blockage detection, allowing the system to monitor its own status using already-present components.

Inventive Principle:
Principle #25Self-service

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 system enhances wound healing by ensuring consistent negative pressure application, reducing the risk of blockages, and providing real-time indicators for user intervention, thereby improving treatment efficacy and patient outcomes.

Implementation Method 1

a source of negative pressure configured to aspirate fluid from the wound

Methodology Applied
Scientific EffectNegative pressure: Pressure Gradient

Implementation Method 2

a pressure sensor configured to measure pressure in the fluid flow path

Methodology Applied
Scientific EffectPressure measurement:

Data Source

PatentEP3941545B1Exhaust blockage detection for negative pressure wound treatment apparatuses
Publication Date: 2025.05.14 SMITH & NEPHEW PLC
  • EP3941545B1 patent drawingFigure 1A
  • EP3941545B1 patent drawingFigure 1B
  • EP3941545B1 patent drawingFigure 1C

AI summary

A negative pressure wound therapy apparatus can include a source of negative pressure configured to aspirate fluid from a wound covered by a wound dressing, a first pressure sensor configured to measure pressure downstream of the source of negative pressure, and a controller configured to, in response to a determination that pressure measured by the first pressure sensor satisfies a threshold indicative of a first blockage downstream of the source of negative pressure, provide an indication of the first blockage. The system can further include a second pressure sensor configured to measure pressure upstream of the source of negative pressure and the controller can be further configured to, in response to a determination that pressure measured by the second pressure sensor satisfies a threshold indicative of a second blockage upstream of the source of negative pressure, provide an indication of the second blockage.