Segmented Stent with Rigid Bendable Segment

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Solution Overview

Problem

During aortic valve replacement, there is a need to prevent adjacent blood vessels, such as coronary arteries, from being compressed or obstructed by the replacement valve, as existing solutions fail to maintain the cross-sectional area effectively.

Innovation Solution

A stent with a radially compressible and expandable first segment and a substantially rigid, bendable second segment that resists radial compression and expansion, positioned in a body lumen to anchor and maintain the cross-sectional area, preventing obstruction of adjacent vessels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid stent is used to maintain the cross-sectional area of a body lumen, then the ability to resist radial compression and expansion is improved, but the ability to anchor in the lumen and adapt to curved configurations deteriorates

Engineering Contradiction:

Improveradial rigidityVSAvoidbendability

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The stent is divided into multiple segments with different mechanical properties: a first segment with radially compressible and expandable struts for anchoring in the body lumen, and a second segment with radially rigid struts for maintaining cross-sectional area and preventing vessel obstruction. This segmentation allows each segment to independently perform its specialized function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the stent are赋予 different local properties: the first segment has flexible, compressible struts that can conform to and anchor in the lumen wall, while the second segment has rigid, non-compressible struts that maintain structural integrity and prevent external compression. Each local region is optimized for its specific functional requirement.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If a radially compressible and expandable stent segment is used to anchor in the body lumen, then the ability to engage the lumen wall is improved, but the ability to resist external radial compression deteriorates

Engineering Contradiction:

Improveanchoring capabilityVSAvoidradial resistance

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

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 stent effectively maintains the cross-sectional area of body lumens, preventing obstruction of coronary arteries by anchoring with the expandable segment and maintaining rigidity with the second segment, thus ensuring unimpeded blood flow and preventing potential occlusions.

Implementation Method 1

a first segment (12) that is radially compressible and expandable... expanding the first segment of the stent in the first body lumen so as to engage a wall defining the first body lumen

Methodology Applied

Scientific EffectRadial expansion: Elasticity

Implementation Method 2

a second segment (14) that is substantially rigid in a radial direction... the second segment... resisting radial compression and expansion

Methodology Applied

Scientific EffectRadial rigidity: Mechanical Force

Data Source

PatentUS8968386B2Stent and method for maintaining the area of a body lumen

Publication Date: 2015.03.03 THE CLEVELAND CLINIC FOUND

AI summary

A stent comprises (a) a first segment that is radially compressible and expandable and (b) a second segment that is substantially rigid in a radial direction. The second segment is bendable to assume a curved configuration while remaining substantially rigid in the radial direction and thereby resisting radial compression and expansion.