Segmental Expansion Mesh for Flexible Vascular Implant Delivery
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Solution Overview
Problem
Existing delivery systems for self-expanding tubular implants, such as stents, lack flexibility and pushability, particularly at the distal end, and do not effectively manage the flattening and fitting of the implant's inner wall, and there is a need for improved control and safety during the release process.
Innovation Solution
A segmental expansion component with a mesh-tubular structure, comprising cross-braided wires and segmental restraints, is designed to provide appropriate flexibility, pushability, and radial support force, ensuring effective flattening and fitting of the implant's inner wall while maintaining safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional auxiliary pushing guidewire is used in the delivery system, then the delivery system can be assembled, but the flexibility and pushability of the guidewire are insufficient
Solution Approach 1:
The guidewire is divided into multiple sections with different properties: a shape memory alloy section for flexibility and tracking, a intermediate section for force transmission, and a pushing section for deliverability. This segmentation allows each section to optimize its function, resolving the contradiction between flexibility and pushability.
Solution Approach 2:
The guidewire uses composite material construction with shape memory alloy (Nitinol) combined with other materials having different mechanical properties. This allows the guidewire to exhibit both flexibility from the shape memory alloy and adequate pushability from the composite structure, resolving the performance limitation.
2Force
If the expandable body is fully expanded to provide radial support, then radial support force is improved, but the contact area with the blood vessel wall is reduced
Solution Approach 1:
The expandable body transitions from a compressed low-contact state during delivery to an expanded high-radial-support state after deployment. This dynamic transformation allows the system to achieve both adequate contact area during delivery and sufficient radial support force after implantation, resolving the contradiction between these two requirements.
3Adaptability or versatility
If the distal end of the tubular implant is made more flexible to improve wall fitting, then the adaptability is improved, but the control and safety during massaging operation are compromised
Solution Approach 1:
The delivery system separates the implant from the delivery mechanism, allowing the implant to be fully flexible for wall adaptation while the delivery system maintains structural integrity for controlled manipulation. The segmental expansion component acts as an interface that provides both flexibility and control.
Solution Approach 2:
The segmental expansion component serves as an intermediary between the delivery system and the implant, providing the necessary flexibility for wall contact while maintaining sufficient structural properties for safe and controlled massaging operations. This mediator resolves the contradiction between adaptability and safety.
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 segmental expansion component ensures appropriate distal axial thrust and radial support force, enhancing the flattening effect on the inner wall of the implant without compromising flexibility, thus improving the safety and efficacy of the delivery process.
Implementation Method 1
the segmental expansion component ensures appropriate distal axial thrust and radial support force, enhancing the flattening effect on the inner wall of the implant without compromising flexibility
Data Source
Figure 1~3
AI summary
The present application relates to a segmental expansion component, and a delivery device and vascular implant system comprising same. The segmental expansion component is provided with at least one segmental expansion unit, and the segmental expansion unit comprises an expandable portion, a proximal restraint portion connected to the proximal end of the expandable portion, and a distal restraint portion connected to the distal end of the expandable portion. The segmental expansion component is obtained by cross-weaving two or more wires into a mesh tube structure and performing segmental restraint according to a predetermined length. In the segmental expansion unit, when the expandable portion is in a radially expanded state, a ratio of the axial length of the expandable portion to the axial length of the proximal restraint portion is 8:1 to 20:1; and the expandable portion has 20 to 200 crossing points per inch of length. The segmental expansion component provided by the present application can obtain suitable distal axial thrust and radial support force without losing flexibility and pushability, thus ensuring the massaging and smoothing effect of the inner wall of an implant.