Guide Extension Catheter Segmented Distal Tip Design
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Solution Overview
Problem
Conventional guide extension catheters face limitations in reaching distal lesion sites within coronary arteries due to insufficient flexibility and followability, leading to difficulties in delivering therapeutic catheters effectively.
Innovation Solution
A guide extension catheter design featuring a distal shaft with a flexible distal end tip and a main body that balances flexibility and pushability, incorporating a radiopaque marker made of a powder mixture for enhanced visibility under X-ray fluoroscopy, and a hydrophilic polymer coating for improved insertability, along with anti-slip features to prevent slippage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the guiding catheter is made with high torque transmission efficiency and kink resistance, then pushability is improved, but followability with serpentine coronary arteries deteriorates
Solution Approach 1:
The catheter is divided into two segments with different properties: a proximal shaft for pushability and a distal shaft for followability. The distal shaft has a smaller diameter and is made of more flexible material to follow the serpentine coronary artery curve, while the proximal shaft maintains rigidity for pushability.
Solution Approach 2:
Different parts of the catheter have different mechanical properties. The distal end tip is made with higher flexibility to navigate the curve of coronary arteries, while the proximal portion maintains higher rigidity for effective pushing. This local differentiation resolves the contradiction between pushability and followability.
2Ease of operation
If the guide extension catheter is made with smaller diameter to improve followability, then insertion into coronary arteries is improved, but structural strength deteriorates
Solution Approach 1:
The distal shaft is segmented from the proximal shaft, allowing the distal portion to have smaller diameter for better followability while the proximal portion maintains larger diameter for structural strength. This segmentation enables different diameter characteristics in different regions.
Solution Approach 2:
The catheter employs composite construction with the distal shaft made of more flexible material and the proximal shaft made of more rigid material. This composite structure allows the smaller distal shaft to maintain sufficient strength while achieving excellent followability.
3Ease of operation
If the distal end tip is made more flexible to improve crossability, then followability with coronary artery curve is improved, but resistance to kinking deteriorates
Solution Approach 1:
The distal shaft is further segmented into a main body and a distal end tip with different flexibility characteristics. The distal end tip is made more flexible for crossability, while the main body maintains higher kink resistance to prevent deformation during manipulation.
Solution Approach 2:
The distal end tip is given local quality of high flexibility to follow the coronary artery curve, while the main body of the distal shaft maintains local quality of kink resistance. This spatial differentiation of mechanical properties resolves the contradiction between crossability and kink resistance.
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 catheter achieves superior followability and crossability within coronary arteries, allowing for more distal insertion and effective delivery of therapeutic catheters to lesion sites while maintaining pushability and resistance to kinking.
Implementation Method 1
the distal end tip includes a marker part in which a powder comprising a radiopaque material is mixed
Implementation Method 2
a hydrophilic polymer coating for improved insertability
Data Source
AI summary
A guide extension catheter including a distal shaft and a proximal shaft, wherein: a main body of the distal shaft is placed on a support base of a three-point bending test jig where a distance between fulcrums is 15 mm; an indenter that approaches the support base at a speed of 10 mm/min in a middle between the fulcrums is pressed against the main body from a lateral side to deform the main body until kinking occurs; and at that time, a maximum load value acting on the main body is 0.1 to 0.6 N. A distal end tip that is more flexible than the main body is provided to the distal shaft. The distal end tip has a length dimension of 2.5 mm or greater, and includes a marker part mixed with a powder made of a radiopaque material.