Stent Retention Structure Using Elongatable Engagement Member
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Solution Overview
Problem
Current drainage stent delivery systems lack effective retention mechanisms for securing stents to the delivery system, leading to challenges in controlled positioning and deployment within body lumens without premature stent deployment.
Innovation Solution
The development of a retention structure featuring an elongate engagement member that can be stretched from a first length to a second length to securely attach and release the stent from the delivery system, utilizing adhesive or frictional engagement to maintain the stent in place during deployment and allow for controlled release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flexible thread or suture is used to releasably connect the drainage stent to the delivery system, then the stent can be secured to the delivery system, but the control over positioning and deployment is insufficient
Solution Approach 1:
The engagement member is designed to be dynamically adjustable in length, transitioning from a first length for secure engagement to a second length for release. This dynamic adjustment allows the system to provide both reliable retention during positioning and ease of deployment when needed, resolving the contradiction between retention reliability and positioning control.
Solution Approach 2:
The engagement member's length parameter is changed from a fixed value to a variable value that can be adjusted between two states. This parameter change enables the system to adapt to different operational requirements - secure engagement during delivery and controlled release during deployment - thereby improving both retention reliability and positioning control.
2Reliability
If the engagement member is secured to maintain stent attachment, then the stent remains in place during placement, but the release mechanism becomes complex
Solution Approach 1:
The engagement member is segmented into a first portion that remains engaged with the stent and a second portion that can be independently actuated. This segmentation allows the release mechanism to be simplified by isolating the actuation function to a specific portion, while maintaining stable attachment through the engaged first portion, thus reducing overall device complexity.
Solution Approach 2:
The release function is extracted from a complex multi-component mechanism and consolidated into a single engageable member that can be actuated by a simple pulling motion. This extraction simplifies the release mechanism while maintaining reliable attachment during the delivery phase.
3Ease of operation
If the engagement member is made stretchable to enable release, then controlled deployment is achieved, but the structural integrity during delivery is compromised
Solution Approach 1:
The engagement member is designed with dynamic mechanical properties that allow it to transition between a rigid state during delivery (maintaining structural integrity) and a flexible state during deployment (enabling controlled release). This dynamic behavior resolves the contradiction between maintaining strength and enabling deployment control.
Solution Approach 2:
The engagement member is pre-configured with the capability to elongate when a pulling force is applied during the deployment phase. This preliminary preparation of the release mechanism allows controlled deployment while the member maintains its structural integrity during the delivery phase before actuation.
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
This solution enables precise control over stent positioning and deployment, ensuring the stent remains attached during placement and is securely released from the delivery system, facilitating effective deployment and retrieval within body lumens.
Implementation Method 1
utilizing adhesive or frictional engagement to maintain the stent in place during deployment
Implementation Method 2
utilizing adhesive or frictional engagement to maintain the stent in place during deployment
Implementation Method 3
The engagement member is configured to be elongated from a first length to a second length greater than the first length by longitudinal movement parallel to the central longitudinal axis of the tubular stent
Data Source
AI summary
A drainage stent delivery system including an elongate shaft of a medical device, a drainage catheter or stent, and an engagement member, such as a distensible member or a compressible member, for selectively coupling the stent to the elongate shaft. The engagement member is positioned between the inner surface of the stent and the outer surface of the elongate shaft and is elongatable from a first length to a second length by longitudinal movement generally parallel to the central longitudinal axis of the stent to release the stent. At the first length, the engagement member is engaged with the inner surface of the stent to secure the stent on the elongate shaft, and at the second length the engagement member is sufficiently disengaged from the inner surface of the stent to release the stent from the elongate shaft such that the elongate shaft may be withdrawn from the stent.