Lubricating Coating for Flexible Medical Instruments in Bent Lumens

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Solution Overview

Problem

Existing medical devices face challenges in maintaining flexibility and lubrication durability during complex procedures in narrow and bent lumens of the body, particularly when delivering to small bending radii or multiple bends, leading to reduced operability and increased tissue damage risk.

Innovation Solution

A medical device with a base layer coated by a surface lubricating layer containing a hydrophilic polymer and a polyurethane with specific elongation and Young's modulus properties, enhancing flexibility and lubrication retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a coating layer containing maleic acid-based polymer substance is formed on the base material surface, then lubricating property is improved, but lubrication retaining property (durability) under severe conditions is insufficient

Engineering Contradiction:
Improvelubricating propertyVSAvoidlubrication retaining property
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent combines a hydrophilic polymer (polymer with carboxy group) and a polyurethane with specific elongation (700% or more) and Young's modulus (5.0 N/mm² or less) to form a surface lubricating layer. This composite material structure provides both excellent lubricating property and superior lubrication retaining property under severe conditions, resolving the contradiction between initial lubrication performance and durability.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If the medical device is made more flexible to navigate complicated lumens, then deliverability to lesion site is improved, but structural integrity and lubrication stability may deteriorate

Engineering Contradiction:
ImproveflexibilityVSAvoidlubrication stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent specifies precise parameter ranges for the polyurethane: elongation percentage of 700% or more and Young's modulus of 5.0 N/mm² or less. These parameter changes ensure the coating layer achieves optimal flexibility to follow complicated lumens while maintaining lubrication stability and structural integrity during insertion and indwelling.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of moving object

If the medical device is used for longer periods in complex procedures, then treatment effectiveness is improved, but friction and tissue damage risk increase

Engineering Contradiction:
Improveoperability durationVSAvoidfriction and tissue damage
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The surface lubricating layer composed of hydrophilic polymer and specific polyurethane maintains continuous lubrication performance throughout the entire operation period. The coating layer's superior lubrication retaining property ensures that friction resistance remains low even after repeated sliding and during prolonged indwelling, preventing tissue damage throughout the procedure.

Inventive Principle:
Principle #20Continuity of useful action

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 combination provides enhanced flexibility and lubrication durability, allowing the device to navigate complex body lumens with reduced friction and tissue damage, improving operability and maintaining lubrication under severe conditions.

Implementation Method 1

a coating layer containing a maleic acid-based polymer substance in which a ratio of a carboxylate is adjusted to a predetermined range is formed on a surface of a base material of a medical device to be inserted into a living body

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

the polyurethane has an elongation percentage of 700% or more and a Young's modulus of 5.0 N/mm² or less

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4349377B1Medical instrument and method for manufacturing same
Publication Date: 2026.03.18 TERUMO KK
  • EP4349377B1 patent drawingFigure 1~2
  • EP4349377B1 patent drawingFigure 3~4
  • EP4349377B1 patent drawingFigure 5A~6

AI summary

An object of the present invention is to provide a technique by which a lubrication retaining property (sliding durability) and flexibility can be exhibited even under severe situations. The present invention relates to a medical device including a base layer and a surface lubricating layer formed on at least a part of the base layer, in which the surface lubricating layer contains a polymer having a carboxy group, or a salt or an ester thereof, and a polyurethane, and the polyurethane has an elongation percentage of 700% or more and a Young's modulus of 5.0 N/mm2 or more.