Curved Dilator Tip for Endovascular Introducer

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Solution Overview

Problem

The deployment of stent-grafts and stents in curved lumens, such as the aortic arch, often results in tissue damage due to the jerking action of the introducer assembly, causing the dilator tip to prod into the vessel wall, leading to complications like stenosis, as the flexible tip is not adequately curved to avoid contact.

Innovation Solution

An endovascular introducer assembly with a dilator tip formed of a flexible material that has a natural curvature of at least 180°, allowing it to maintain a U-shape or more, and a guide wire with varying flexibility regions to ensure the tip remains curved during deployment, preventing it from jutting forward and minimizing contact with the vessel wall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the dilator tip is made flexible to follow the guide wire, then the introducer can navigate curved vasculature, but the tip still prods into the vessel wall during implant release causing tissue damage

Engineering Contradiction:

Improveability to navigate curved vasculatureVSAvoidvessel wall trauma

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The dilator tip is designed with a permanent curved configuration (U-shape or more) rather than being straight. This curvature is built into the tip structure itself, allowing it to follow the curved path of the vasculature without proding forward during implant release. The curved geometry distributes contact forces along the curved surface rather than concentrating them at a sharp tip, thereby reducing vessel wall trauma while maintaining navigation capability through curved anatomy.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Strength

If the dilator tip is made harder to resist proding action, then it can better maintain position, but it causes more tissue damage when prodding into the vessel wall

Engineering Contradiction:

Improveresistance to proding actionVSAvoidtissue damage

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The curved configuration of the dilator tip changes the mechanical interaction with the vessel wall. Instead of a straight tip concentrating force at a point, the curved surface distributes the proding action along an arc, reducing stress concentration. This allows the tip to maintain position stability while minimizing localized tissue damage.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the dilator tip by introducing a permanent curve (U-shape or more). This parameter change transforms the tip from a straight configuration to a curved one, fundamentally altering how it interacts with the vessel wall during deployment. The curvature radius and shape are optimized to balance position maintenance with tissue protection.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If the guide wire is made stiffer to maintain shape, then the dilator tip can follow the guide wire path, but the assembly creates more jerking action during implant release

Engineering Contradiction:

Improveshape maintenanceVSAvoidjerking action

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The curved dilator tip acts as a buffer that absorbs and distributes the jerking forces generated during implant release. The curvature allows the tip to flex and absorb shock rather than transmitting sharp jerking motions directly to the vessel wall. This reduces the harmful effects of jerking action while maintaining the overall shape and path guidance function of the assembly.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 curved dilator tip effectively reduces the risk of vessel wall trauma during deployment, ensuring smoother implant placement and reducing the likelihood of complications like stenosis by maintaining a curved configuration that avoids direct contact with the vessel wall.

Implementation Method 1

The dilator tip is formed of a flexible material able to curve so as to follow the path of the guide wire over which is slides

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9161850B2Introducer for endovascular implants

Publication Date: 2015.10.20 COOK MEDICAL TECHNOLOGIES LLC

AI summary

An introducer assembly for introducing a stent-graft or other device into a vessel of a patient is provided with a dilator tip which is naturally curved, preferably to be substantially a U-shape. The dilator tip is flexible so as to be able to become substantially straight with a guide wire therein and yet to be able to curve back towards its natural curvature during deployment of an implant. The curvature of the dilator tip can ensure that the dilator tip does not cause damage to the vessel wall during deployment of an implant carried thereon, as can occur with straight dilator tips.