Stent Annular Body Design for Vascular Navigability
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Solution Overview
Problem
Current stents, particularly self-expanding types used in coronary and cerebrovascular regions, face challenges in reducing diameter during insertion due to design limitations, which can lead to difficulties in navigating through small and bent blood vessels effectively.
Innovation Solution
The design incorporates annular bodies with one end side and other end side bent portions connected by connection linear portions, where axial linear portions extend parallel to the stent axis and bent portions extend circumferentially, allowing for reduced diameter compression and improved radial deformability, enabling stable indwelling even in small and bent vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a conventional self-expanding stent design is used, then the stent can be inserted into the body, but the diameter cannot be sufficiently reduced at the connection portion, making it difficult to navigate through small and bent blood vessels
Solution Approach 1:
The stent is divided into multiple connection portions along its length, with each connection portion independently designed with bent portions that can be compressed. This segmentation allows different parts of the stent to be compressed uniformly, enabling the entire stent to be reduced to a smaller diameter for navigation through tortuous vessels while maintaining structural integrity
Solution Approach 2:
The connection portions incorporate bent portions with specific curvature radii (R1 and R2) that allow the stent to flex and compress effectively. The curved geometry enables the rigid stent structure to deform into a more compact form during insertion while maintaining strength, and then expand back to its original shape at the target site
2Ease of operation
If the stent diameter is reduced for insertion into small vessels, then navigability improves, but the expansion force and radial strength may be compromised
Solution Approach 1:
The stent is designed with dynamic characteristics that allow it to transition between two states: a compressed low-diameter state for navigation through small and bent vessels, and an expanded high-diameter state for providing radial strength and support at the target site. The bent portions act as mechanical springs that store elastic energy during compression and release it during expansion
Solution Approach 2:
The stent's physical parameters (diameter, shape, and structural configuration) are changed dynamically during the procedure. The bent portions are designed with specific geometric parameters (curvature radii R1 and R2, segment lengths) that enable the stent to achieve adequate compression ratios while maintaining sufficient expansion force and radial strength when deployed
3Ease of manufacture
If the stent is designed with uniform structure, then manufacturing is simplified, but the ability to follow complex vascular paths and maintain stability in bent vessels is reduced
Solution Approach 1:
The stent incorporates local variations in structure at the connection portions, where bent portions with specific curvature radii (R1 and R2) are introduced to enhance flexibility and adaptability. These localized structural modifications allow the stent to follow complex vascular paths and maintain stability in bent vessels, while the overall uniform structure of the main body is preserved to maintain manufacturing simplicity
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 design enhances the stent's ability to reduce diameter for insertion and maintain stability within small and complex vascular structures, such as cerebral arteries, while ensuring uniform expansion force and improved blood vessel followability.
Implementation Method 1
the stent is formed in a substantially cylindrical shape, configured to be compressed in a central axis direction at the time of in-vivo insertion, and to expand outward so as to be able to restore a shape before compression
Data Source
AI summary
In an in-vivo indwelling stent, a plurality of annular bodies formed in a circular shape with linear components are arranged in an axial direction, and adjacent annular bodies are connected by connection portions. Each of the annular bodies includes connection linear portions that connect one end side bent portions and other end side bent portions. One of the connection linear portions of the annular bodies located in a central portion of the stent includes axial linear portions that have one end side vertices of the one end side bent portions as starting ends and extend so as to be parallel to the axial direction of the stent, and bent portions that have starting ends at terminal ends of the axial linear portions and extend in a circumferential direction of the stent.