Catheter Tip Separation via Composite Strip Bonding

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Solution Overview

Problem

Existing methods for manufacturing catheters with separated tip configurations face challenges in creating distinct, movable tip members that can maintain bi-directional fluid flow effectively during hemodialysis procedures, particularly in ensuring strong bonding between different materials while allowing for the separation of lumens at the distal end.

Innovation Solution

The method involves extruding a thermoplastic material through a die to form a catheter body with a septum between two lumens, inserting a strip with different bonding capabilities between the lumens, and using a combination of mechanical and chemical bonding to create separated tip members, where one section of the strip does not bond with the extrusion material, allowing for the formation of distinct, movable tips.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a strip with uniform bonding capability is used throughout its length, then bonding strength with extrusion material is maximized, but separation of tip members cannot be achieved

Engineering Contradiction:
Improvebonding strengthVSAvoidseparation capability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The strip is designed with spatially varying bonding properties: the proximal portion has bonding capability matching the extrusion material for strong attachment, while the distal portion has reduced or incompatible bonding capability to enable separation. This local differentiation of material properties resolves the contradiction between achieving strong bonding and enabling separation.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the same material is used for both bonding and separation sections of the strip, then manufacturing simplicity is maintained, but functional differentiation is lost

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidfunctional differentiation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The strip is constructed as a composite structure with at least two different materials: a bonding material in the proximal portion that chemically or mechanically bonds to the extrusion material, and a separation material in the distal portion that does not bond or has reduced bonding capability. This composite approach enables functional differentiation while maintaining manufacturing feasibility.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If extensions are formed during extrusion, then material distribution is improved, but additional post-processing steps are required

Engineering Contradiction:
Improvematerial distributionVSAvoidprocess complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The extensions formed during extrusion are removed in a post-processing step through cutting or grinding. This extraction of the extensions eliminates the complexity they introduce while preserving the benefit of improved material distribution achieved during the extrusion process.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach enables the creation of catheters with effectively separated tip members that maintain structural integrity and bi-directional fluid flow, enhancing the efficiency of hemodialysis procedures by ensuring strong bonding and precise separation of lumens at the distal end.

Implementation Method 1

The extrusion material may be extruded with an extruder heated before the extrusion process, and/or cooled after the extrusion process.

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

some catheters are formed by extruding molten polymer material through a die

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

The first material is capable of forming a covalent bond with the extrusion material. The chemical bond formed between the first material and the extrusion material may have an attractive bond greater than the ionic forces of the first material and the extrusion material, i.e, an integral bond.

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP2448616B1Method for manufacturing a separated tip catheter
Publication Date: 2016.08.03 COVIDIEN LP
  • EP2448616B1 patent drawingFigure 1
  • EP2448616B1 patent drawingFigure 2~3
  • EP2448616B1 patent drawingFigure 4~5

AI summary

A method for manufacturing a separated tip catheter having a separated tip configuration includes the steps of: extruding an extrusion material through a die to form a catheter including a catheter body having a proximal end and a distal end and defining a first lumen and a second lumen, the catheter body having a septum positioned between the first and second lumens; and feeding a strip into the die so that the strip is positioned between the first lumen and the second lumen along a length of the catheter, the strip having a first proximal section formed of a first material capable of bonding with the extrusion material and a second distal section formed of a second material incapable of bonding with the extrusion material.