Radially Adjustable Stent Delivery Tip for Vessel Safety

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Solution Overview

Problem

Stent-delivery assemblies with traumatic tips can cause injury or damage to vessels during stent placement and retrieval, and may dislodge or agitate lesions, while the balloon often gets caught or damaged by the stent during deployment.

Innovation Solution

A stent-delivery assembly with a radially adjustable tip that changes diameter in response to guidewire position, allowing for an a-traumatic shape during insertion and expansion, and accommodating fluid to adjust its dimensions for safe passage through the stent, minimizing vessel irritation and facilitating retrieval.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the stent-delivery assembly has a rigid tip for structural support, then the assembly maintains stability during delivery, but the tip causes injury or damage to the vessel wall

Engineering Contradiction:

Improvestructural stabilityVSAvoidvessel wall injury

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The tip is designed with radially adjustable characteristics that allow it to dynamically change its outer diameter. During delivery, the tip maintains a larger diameter for stability, then compresses to a smaller diameter to pass through the stent and minimize vessel injury. This dynamic adaptation resolves the contradiction between needing structural stability and avoiding vessel wall damage.

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If the tip maintains a large outer diameter for stability, then the assembly is stable during delivery, but the balloon cannot pass through the stent during retrieval

Engineering Contradiction:

Improvedelivery stabilityVSAvoidballoon retrieval

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The radially adjustable tip compresses from a first outer diameter (larger than or equal to the catheter inner diameter) to a second outer diameter (smaller than the stent inner diameter). This dynamic size change enables the tip to provide stability during delivery while allowing the balloon to pass through the stent during retrieval, resolving the contradiction between delivery stability and retrieval ease.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If the tip is compressed to pass through the stent, then retrieval is facilitated, but the tip may cause vessel irritation during insertion

Engineering Contradiction:

Improveretrieval facilitationVSAvoidvessel irritation

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The tip dynamically adjusts its diameter based on the operational phase: maintaining a larger diameter during insertion to minimize vessel irritation, then compressing to a smaller diameter during retrieval to pass through the stent. This temporal separation of functions resolves the contradiction between retrieval facilitation and vessel irritation prevention.

Inventive Principle:

Principle #15Dynamics

4Volume of moving object

If the stent-delivery assembly has a small profile for easy navigation, then the assembly can navigate narrow vessels, but the tip lacks sufficient structural support

Engineering Contradiction:

Improveassembly profileVSAvoidtip structural support

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The tip provides strong structural support when needed (during delivery and deployment) by maintaining a larger diameter, then compresses to a smaller profile for navigation through narrow vessels and stent passage. This dynamic profile adjustment resolves the contradiction between navigation ease and structural support.

Inventive Principle:

Principle #15Dynamics

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 assembly reduces vessel damage and dislodgment risks, enabling safe stent placement and retrieval by maintaining an a-traumatic shape and accommodating fluid expansion for smooth passage, thus improving the delivery and deployment process.

Implementation Method 1

the tip includes an elastic tip that is configured to accommodate a predetermined amount of a fluid... compression of the tip using the stent causes the predetermined amount of fluid to expand a portion of the radially adjustable middle portion

Methodology Applied

Scientific EffectElastic expansion: Elasticity

Implementation Method 2

compression of the tip using the stent causes the predetermined amount of fluid to expand a portion of the radially adjustable middle portion such that the first tip outer diameter is greater than the catheter inner diameter

Methodology Applied

Scientific EffectCompression-induced radial expansion: Poisson's Effect

Data Source

PatentUS10258491B2Deformable tip for stent delivery and methods of use

Publication Date: 2019.04.16 INSPIRE M D LTD

AI summary

A stent-delivery assembly that includes a catheter; an expandable stent that is movable, relative to the catheter, from a first position to a second position; and a guidewire assembly extending through a longitudinal passage of the catheter and a longitudinal passage of the stent, the guidewire assembly being movable, relative to the catheter, from a third position to a fourth position. While the expandable stent is in the first position and while the guidewire assembly is in the third position, the stent-delivery assembly has an a-traumatic shape. While the expandable stent is in the second position and while the guidewire assembly is in the fourth position, the guidewire assembly is capable of passing through the stent to allow for retrieval of the stent-delivery assembly. Methods of use and manufacture are also included.