Multilayer Tubular Membrane Structure for Tear-Resistant Stent Grafts

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Solution Overview

Problem

Existing stent grafts face issues with membrane portions being torn or broken at sutured locations due to material choice, compromising low liquid permeability.

Innovation Solution

A multi-layer membrane structure comprising a first layer of fiber and a second layer with lower liquid permeability, where the first layer provides strength against tearing and the second layer ensures low permeability, with an adhesive layer in between.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tubular treatment tool is used to deliver a stent to a body lumen, then the stent can be delivered to the target location, but the tool becomes clogged with tissue debris and requires frequent cleaning or replacement

Engineering Contradiction:
Improvetool functionalityVSAvoidtool maintenance
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies a membrane formed from a tube with porous material that lines the interior surface of the tubular treatment tool. This flexible porous membrane allows tissue debris to pass through while maintaining the structural integrity of the tool, preventing clogging without requiring frequent cleaning or replacement. The membrane acts as a filter that can be integrated into the existing tool structure.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent utilizes porous material to form the membrane that lines the interior surface of the treatment tool. The porous structure allows fluid and tissue debris to pass through while preventing larger debris from blocking the tool lumen. This porous membrane enables continuous operation of the tool without frequent interruptions for cleaning.

Inventive Principle:
Principle #31Porous materials

2Reliability

If a tubular treatment tool is used to deliver a stent, then the stent can be delivered, but the tool cannot be easily sterilized between uses

Engineering Contradiction:
ImprovesterilityVSAvoidsterilization process
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The porous membrane formed from a tube can be integrated into the sterilization process. The membrane structure allows for effective sterilization between uses while maintaining its filtering function. The flexible nature of the membrane enables it to withstand sterilization procedures without compromising its integrity or filtering capability.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The porous material used in the membrane facilitates sterilization by allowing sterilizing agents to penetrate through the membrane structure. This enables thorough sterilization of the treatment tool between uses, ensuring sterility while simplifying the sterilization process compared to solid barrier materials.

Inventive Principle:
Principle #31Porous materials

3Volume of moving object

If a tubular treatment tool is used to deliver a stent, then the stent can be delivered, but the tool cannot be collapsed to a small profile for delivery through a catheter

Engineering Contradiction:
Improvetool profileVSAvoidtool structural integrity
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The membrane formed from a tube with porous material provides a flexible yet structurally sound lining for the treatment tool. This flexible membrane allows the tool to collapse to a small profile for delivery through a catheter while maintaining sufficient structural integrity to perform its function. The thin film structure can be compressed without compromising the porous filtering capability.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The membrane structure allows the treatment tool to undergo parameter changes in terms of volume and shape during delivery. The porous material maintains its structural properties while allowing the overall tool profile to be reduced for catheter delivery, then expanded at the target site to perform its filtering function.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4026517B1Membrane body for tubular treatment device and tubular treatment device
Publication Date: 2026.04.29 SB KAWASUMI LABORATORIES INC
  • EP4026517B1 patent drawingFigure 1
  • EP4026517B1 patent drawingFigure 2
  • EP4026517B1 patent drawingFigure 3~4

AI summary

A membrane body for a tubular treatment device includes a tubular membrane portion (12). The membrane portion forms a multi-layer structure having a first layer (21) formed of a fiber and a second layer (22) having liquid permeability lower than that of the first layer.