Stent Connection Webs with Recesses for Low Crimp Profile

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Solution Overview

Problem

Existing stent designs face challenges in achieving a compact crimp profile, high bending flexibility, and low opening pressure, while maintaining sufficient radial force and resistance to fatigue under dynamic loads, especially during expansion and deployment in tortuous vessels.

Innovation Solution

The stent design features connection webs with end branches that lead at right angles into sub-webs via termination bends, with recesses at the mouth region corners, and flat deflection bends that nestle between meander bends, optimizing crimpability and flexibility, and reducing the crimping profile and opening force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional stent designs are used, then structural stability is maintained, but crimping profile and opening pressure are increased

Engineering Contradiction:

Improvecrimping profileVSAvoidradial force

Core Design Contradiction:

Volume of moving objectVSStrength

Solution Approach 1:

The connection webs are designed with specific curvature radii at bends and corners, creating smooth curved transitions instead of sharp angles. This curvature optimization allows the stent to achieve a compact crimped state while maintaining structural integrity and radial force when expanded

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The stent structure is divided into discrete components (helix webs, sub-webs, connection webs with end branches) that can independently deform during crimping and expansion. This segmentation allows each element to contribute to the reduced crimping profile while collectively maintaining radial strength

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If conventional stent designs are used, then radial force is maintained, but axial flexibility is reduced

Engineering Contradiction:

Improveaxial flexibilityVSAvoidradial force

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The connection webs are designed with dynamic deformation capabilities, allowing them to flex axially during stent deployment while maintaining radial support. The end branches and termination bends enable the structure to adapt to vessel curvature while preserving radial force

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Different regions of the stent structure have optimized properties: connection webs provide axial flexibility through their bent geometry, while helix webs and sub-webs maintain radial strength. The mouth region corners with recesses provide localized flexibility without compromising overall structural integrity

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If conventional stent designs are used, then opening pressure is maintained, but crimpability is reduced

Engineering Contradiction:

ImprovecrimpabilityVSAvoidopening pressure

Core Design Contradiction:

Ease of manufactureVSStress or pressure

Solution Approach 1:

The optimized curvature radii at all bends and corners eliminate stress concentration points, allowing the stent to be crimped to a smaller profile without requiring excessive opening pressure to deploy. The smooth curved transitions enable easier compression while maintaining deployability

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Reliability

If conventional stent designs are used, then structural stability is maintained, but resistance to fatigue under dynamic loads is reduced

Engineering Contradiction:

Improveresistance to fatigueVSAvoidstructural stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The rounded bends and corners with optimized radii eliminate sharp stress concentration points that would initiate fatigue cracks under dynamic loading. The curved geometry distributes stresses more uniformly throughout the structure, enhancing fatigue resistance while maintaining structural stability

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The recesses at mouth region corners and the curved termination bends pre-compliance features that absorb and distribute dynamic loads before they reach critical stress points, providing beforehand cushioning against fatigue damage

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3021797B1stent

Publication Date: 2023.04.12 BIOTRONIK AG

Figure 1
Figure 2~3
Figure 4

AI summary

A stent with a preferably cylindrical circumferential wall (1) designed as an open, lattice-like, expandable supporting structure with a longitudinal axis (L) is provided, said stent comprising - helix webs (2.1, 2.2, 2.3) running around helically in windings (W) about the longitudinal axis (L) with a helical primary form and a meandering secondary form, which forms meander bends (3.1, 3.2) with a direction of curvature alternating in the circumferential direction (U) and also forms sub-webs (4.1, 4.2) connecting the meander bend (3.1, 3.2), and - connection webs (7) bridging the helix webs (2.1, 2.2, 2.3) of two adjacent windings (W) with a primary direction of extension (H) parallel to the longitudinal axis (L), said connection webs being joined at their sub-web-side ends (8) to adjacent sub-webs (4.1) of the respective helix web (2.1, 2.2, 2.3) and having a flat, zigzag-like shape with two end branches (9.1, 9.2) and an intermediate central branch (10), wherein the end branches (9.1, 9.2) each lead via a termination bend (12) at least approximately at right angles into the respective sub-web (4.1) and the comers in the mouth region (M) between the termination bends (12) and the sub-webs (4.1) are provided with a recess (14).