Stent Delivery Core Assembly Recapture Mechanism
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Solution Overview
Problem
Current stent delivery systems face challenges in precisely positioning and repositioning stents within blood vessels, particularly in tortuous geometries, due to difficulties in recapturing, collapsing, and resheathing partially expanded stents, which can lead to suboptimal placement and increased risk of vessel damage.
Innovation Solution
A stent delivery system featuring a core assembly with a constraining member and engagement component that allows for the securement and controlled movement of the stent, enabling recapture, collapse, and resheathing of the stent even after partial expansion, along with a rotatable core member to navigate tortuous vessels without causing vessel abrasion or perforation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a stent is expanded at the treatment location using traditional methods, then the stent provides vascular support, but the initial placement position cannot be adjusted once expanded
Solution Approach 1:
The stent delivery system employs a dynamic recapture mechanism where the stent can be transitioned between expanded and compressed states. The core assembly includes engagement components that can grip the stent after expansion, allowing it to be withdrawn and repositioned. This dynamic capability resolves the contradiction by making the stent placement process adjustable rather than fixed upon initial expansion.
Solution Approach 2:
The system performs preliminary engagement of the stent by the core assembly before final deployment. The engagement components are positioned to secure the stent in advance, allowing the operator to verify placement accuracy and make adjustments before the stent is permanently fixed in the vessel wall.
2Length of moving object
If the stent is advanced through tortuous vessels, then the stent reaches the treatment site, but the rigid delivery system may cause vessel abrasion or perforation
Solution Approach 1:
The core member of the delivery system is designed with curved or flexible geometry rather than a straight rigid structure. This allows the delivery system to navigate tortuous vascular pathways by conforming to the natural curves of the vessels, eliminating the harmful abrasion and perforation risks associated with forcing a rigid system through curved anatomy.
Solution Approach 2:
The delivery catheter and core assembly incorporate flexible materials and thin-walled structures that can bend and flex to follow the contours of the vasculature. This flexibility enables the system to reach distant treatment sites through tortuous paths without causing mechanical damage to the vessel walls.
3Ease of operation
If the stent is securely engaged in the delivery system, then the stent can be recaptured and repositioned, but the engagement mechanism increases device complexity
Solution Approach 1:
The engagement components are integrated into the core assembly structure rather than being separate attached elements. The core member incorporates gripping surfaces and engagement features that are combined with the推进 and deployment functions, reducing the number of discrete parts while maintaining the recapture capability.
Solution Approach 2:
The core assembly serves multiple functions: it propels the stent to the target site, engages and secures the stent for recapture, and controls the expansion timing. This multi-functionality reduces overall device complexity by eliminating the need for separate mechanisms for each function.
Data Source
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Figure 3A~3B
AI summary
A stent delivery system can include a core member, first and second restraints, and a stent engagement component. The core member can have a distal segment. The first and second restraints can be coupled to the core member distal segment and axially spaced apart from each other to provide an axial gap. The first and second restraints can each have an outer profile that tapers radially inwardly in directions away from the gap. The stent engagement component can be at least partially disposed in the axial gap between the first and second restraints such that the component is slidably and rotatably coupled to the core member distal segment.