Pivoting Stent Attachment Mechanism for Complete Release

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Solution Overview

Problem

Current stent deployment systems often fail to achieve complete release of the stent due to the stent becoming stuck on the attachment mechanism, particularly due to twisting forces during delivery.

Innovation Solution

A delivery system with a pivoting attachment mechanism that includes a casing, a lug, and fingers to securely engage the stent, allowing the lug to pivot relative to the casing upon retraction of the delivery sheath capsule, ensuring the stent is released from the system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional attachment mechanism is used to secure the stent during delivery, then the stent can be held firmly in place, but the stent may become stuck on the attachment mechanism during deployment, preventing complete release

Engineering Contradiction:
Improvestent retention reliabilityVSAvoidstent release completeness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The attachment mechanism employs a pivoting lug that can rotate between engaged and disengaged positions. During delivery, the lug pivots to engage with the stent frame for secure retention. During deployment, the lug pivots again to release the stent, enabling complete disengagement and preventing entrapment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The attachment mechanism is divided into separate functional components: a casing that houses the mechanism, a pivoting lug that performs the engagement/disengagement action, and fingers that contact the stent frame. This segmentation allows each component to be optimized for its specific function while enabling smooth transition between retention and release modes.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the delivery sheath capsule is retracted to deploy the stent, then the stent can expand and be released, but twisting forces during delivery may cause the stent to get caught on the attachment mechanism

Engineering Contradiction:
Improvedeployment efficiencyVSAvoidrelease completeness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The pivoting lug is designed with a geometry and pivot mechanism that proactively prevents engagement with the stent frame during the deployment phase. As the delivery sheath capsule is retracted, the lug automatically pivots to a disengaged position, counteracting any twisting forces that might otherwise cause the stent to get caught.

Inventive Principle:
Principle #9Preliminary anti-action

3Strength

If the attachment mechanism uses a fixed structure to ensure secure engagement, then the stent can be held firmly, but the mechanism cannot accommodate twisting forces during delivery and deployment

Engineering Contradiction:
Improveengagement strengthVSAvoidflexibility to twisting forces
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The attachment mechanism transitions from a fixed structure to a dynamic pivoting system. The lug can rotate about a pivot point within the casing, allowing it to adapt to twisting forces during delivery while maintaining strong engagement with the stent frame when needed. This dynamic capability enables the mechanism to accommodate various delivery scenarios without compromising engagement strength.

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

Prevents stent entrapment by allowing the stent to be released effectively from the delivery system, ensuring complete deployment without getting caught on the attachment mechanism.

Implementation Method 1

The attachment mechanism is configured to pivot relative to the inner shaft assembly upon retraction of the delivery sheath capsule to release the stent from the delivery system

Methodology Applied
Scientific EffectPivoting mechanism: Hinge

Data Source

PatentEP2595581B1Attachment mechanism for stent release
Publication Date: 2017.11.01 MEDTRONIC INC
  • EP2595581B1 patent drawingFigure 1
  • EP2595581B1 patent drawingFigure 2~3
  • EP2595581B1 patent drawingFigure 4~7

AI summary

An attachment mechanism ( 120 ) for coupling a stent to a delivery system is disclosed. The attachment mechanism is configured to pivot relative to an inner shaft assembly ( 112 ) of the delivery system in order to release the stent from the delivery system.