Stent Delivery Expandable Member Axial Control
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Solution Overview
Problem
Current stent delivery systems face challenges in conforming to the tortuous vasculature and ensuring adequate blood flow around aneurysms, particularly in preventing blood flow diversion and ensuring perfusion to adjacent structures during stent deployment.
Innovation Solution
A stent delivery system comprising an elongate body, a stent, a core wire, and an expandable member, where the expandable member is configured to facilitate the expansion of the stent by engaging its inner surface, with blocking members to control the movement of the expandable member and prevent axial compression, allowing for self-expansion when unrestrained, thereby conforming to vessel shapes and maintaining blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stent is compressed within the delivery system for navigation through tortuous vessels, then the device can be delivered to the target site, but the stent may undergo axial foreshortening and inversion during deployment
Solution Approach 1:
The delivery system is divided into distinct functional segments: an elongate body for navigation, a core wire for support, and an expandable member for controlled expansion. This segmentation allows each component to perform its specific function without interfering with others, preventing stent inversion while enabling delivery through tortuous vessels.
Solution Approach 2:
The expandable member acts as an intermediary between the core wire and the stent. It facilitates controlled expansion by engaging the inner surface of the stent and preventing axial compression, thereby maintaining stent orientation and preventing inversion during the deployment process.
2Ease of operation
If the expandable member is allowed to move freely on the core wire, then it can be positioned easily, but it cannot effectively control stent expansion and prevent axial compression
Solution Approach 1:
The expandable member is designed with dynamic characteristics, allowing it to be freely positionable on the core wire during delivery. Once positioned, it becomes dynamically active in preventing axial compression of the stent during expansion, thus providing both ease of positioning and reliable control.
Solution Approach 2:
The expandable member changes its functional parameters based on its position and the expansion phase. During delivery, it allows free movement; during expansion, it engages the stent inner surface to prevent axial compression, thereby controlling the expansion process reliably.
3Reliability
If the stent expands radially to treat the aneurysm, then blood flow can be redirected away from the aneurysm, but adjacent structures may be deprived of necessary blood flow
Solution Approach 1:
The stent is designed with local quality variations, having different expansion characteristics and porosity in different regions. This allows selective blood flow redirection to occlude the aneurysm while maintaining adequate perfusion to adjacent structures through controlled porosity and expansion patterns.
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 system effectively deploys stents that conform to the vasculature, direct blood flow away from aneurysms, and ensure adequate perfusion to adjacent tissues, reducing the risk of stent foreshortening and inversion, thus enhancing the deployment process and clinical outcomes.
Implementation Method 1
The expandable member is configured to facilitate the expansion of at least a portion of the stent to the expanded configuration by expanding and engaging the inner surface of the stent
Implementation Method 2
The core wire is extensible through the elongate body and the stent has a distal region or terminal portion
Implementation Method 3
The blocking member is configured to limit the movement of the expandable member relative to the core wire
Data Source
Figure 1
Figure 2~3B
Figure 3C~3F
AI summary
Described herein are delivery systems for flexible implantable devices or stents that can, for example, navigate tortuous vessels of the neurovasculature. In accordance with some embodiments, a stent delivery system (5) is provided that comprises an elongate body (8), a stent (66), a core wire (59), and an expandable member (54). The elongate body comprises a distal portion, a proximal portion, and an inner surface extending from the distal portion to the proximal portion. The distal portion is configured to extend within a blood vessel of a patient. The stent is expandable from a compressed configuration to an expanded configuration. The core wire is extensible through the elongate body and the stent and has a distal region or terminal portion. The expandable member is disposed along the core wire. The expandable member is configured to facilitate the expansion of at least a portion of the stent to the expanded configuration by expanding and engaging the inner surface of the stent.