Stent Profiles for Balloon Catheter Grip and Fabrication

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Solution Overview

Problem

Conventional stent delivery methods face issues with uneven crimping leading to sharp edges and reduced flexibility, which can damage or catch on the patient's vasculature, and excessive expansion causing delivery difficulties through narrow passages.

Innovation Solution

A stent design with tapered sections for improved attachment and flexibility, featuring a proximal section tapering inward to the proximal end and a distal section tapering inward to the distal end, and a mold for fabricating stents with oscillating cross-sections to enhance grip and navigation through bodily lumens.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional crimping techniques are used to attach the stent to the catheter, then the stent can be delivered through the vasculature, but the crimping is uneven leading to sharp edges that can damage or get caught on the patient's vasculature

Engineering Contradiction:

Improvestent deliveryVSAvoidsharp edges damaging vasculature

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The stent is pre-formed with tapered ends before crimping, so that when the stent is compressed onto the catheter, the tapered geometry ensures uniform contact and prevents sharp edge formation during the crimping process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The stent geometry is modified by tapering the ends, which changes the physical parameters of the stent structure to achieve more uniform stress distribution during crimping and eliminate sharp edges

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If conventional crimping techniques are used to attach the stent to the catheter, then the stent can be delivered, but the crimping decreases flexibility of the stent making it hard to deliver through curvatures

Engineering Contradiction:

Improvestent deliveryVSAvoidstent flexibility

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The stent has different geometries in different sections: the ends are tapered to improve crimping, while the body maintains its original structure to preserve flexibility and radial strength where needed

Inventive Principle:

Principle #3Local quality

3Ease of operation

If the balloon catheter is expanded before delivery, then the stent can be attached to the catheter, but the balloon catheter causes excessive expansion of the stent making it hard to transport through narrow passages

Engineering Contradiction:

Improvestent attachmentVSAvoidstent diameter

Core Design Contradiction:

Ease of operationVSLength of moving object

Solution Approach 1:

The stent is pre-formed with tapered ends that allow it to be crimped onto the catheter in a compressed state, enabling attachment without requiring pre-expansion of the balloon catheter

Inventive Principle:

Principle #10Preliminary action

4Ease of operation

If the balloon catheter is expanded before delivery, then the stent can be attached to the catheter, but the distal and proximal ends expand further causing upward tapered edges that can get caught in the patient's vasculature

Engineering Contradiction:

Improvestent attachmentVSAvoidtapered edges getting caught in vasculature

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

Instead of allowing the balloon expansion to create the tapered shape, the invention inverts the approach by pre-forming the tapered shape on the stent itself before crimping, so the taper is created by the stent geometry rather than by expansion

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS7381048B2Stents with profiles for gripping a balloon catheter and molds for fabricating stents

Publication Date: 2008.06.03 ABBOTT CARDIOVASCULAR SYSTEMS INC

AI summary

Embodiments of stents having profiles that improve gripping of the stent on a stent delivery system are provided. Additionally, embodiments of molds for fabricating the stents are provided.