Gradient Rigidity Contrast Markers for Stent Delivery Kinking
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Solution Overview
Problem
The existing stent delivery systems experience kinking issues due to the placement of contrast markers, which can lead to poor insertion operability and safety risks, as the markers can cause the stent to partially expand or slip out.
Innovation Solution
A delivery system with a shaft portion, a living body indwelling member, and contrast markers arranged such that the markers' bending rigidity decreases in a gradient away from the stent, preventing kinking by minimizing excessive changes in rigidity and ensuring the markers do not overlap the stent, thereby improving insertion safety and operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a hard contrast marker is disposed at a position overlapping the stent, then the stent position is visible during X-ray fluoroscopy, but the catheter kinks between the hard contrast marker and the stent, resulting in poor insertion operability
Solution Approach 1:
The contrast marker is designed with non-uniform bending rigidity along its length, with the distal end having lower bending rigidity than the proximal end. This local variation in mechanical properties allows the distal end to flex and conform to the stent contour, preventing kinking while maintaining radiopacity for imaging.
Solution Approach 2:
The bending rigidity parameter of the contrast marker is changed along its length, creating a gradient from higher rigidity at the proximal end to lower rigidity at the distal end. This parameter change enables the marker to maintain structural integrity while allowing the distal portion to adapt to the stent geometry, eliminating kinking issues.
2Ease of operation
If a hard contrast marker is disposed at a position not overlapping the stent, then the catheter insertion is easier, but the stent position cannot be accurately visualized during X-ray fluoroscopy
Solution Approach 1:
The contrast marker employs local quality variation with different bending rigidity zones, allowing the distal end to flex and contact the stent for accurate positioning visualization, while the proximal end maintains higher rigidity for easy catheter insertion and manipulation.
3Stability of the object's composition
If the contrast marker has high bending rigidity throughout, then the marker structure is stable, but the catheter kinks between the marker and stent, causing the stent to partially expand or slip out
Solution Approach 1:
The contrast marker features local quality differentiation where the proximal portion maintains high bending rigidity for structural stability, while the distal portion has reduced bending rigidity to allow conformal contact with the stent, preventing kinking and ensuring reliable stent deployment.
Solution Approach 2:
The contrast marker is effectively segmented into zones with different bending rigidity characteristics, with the distal end having lower rigidity to prevent kinking and the proximal end having higher rigidity to maintain overall marker stability and structural integrity.
Data Source
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AI summary
[Problem] There is provided a delivery system for a living body indwelling member which can suppress kink probably occurring in an end portion of a contrast marker, and which can improve insertion operability and safety. [Means for Resolution] A delivery system for a living body indwelling member (10) includes a shaft portion (20) that extends in a long length, a stent (70) that is disposed on a distal side of the shaft portion (20), and that is caused to indwell a living body, and contrast markers (81) and (82) that are disposed on at least one side of a proximal side or a distal side of the stent (70), and that have contrasting property. The contrast markers (81) and (82) are arranged up to a position where the contrast markers do not overlap the stent (70) in a separating direction away from the stent (70) from a position where the contrast markers overlap the stent (70) at an axial position of the shaft portion (20), or from a position where the contrast markers coincide with an edge portion of the stent (70). Bending rigidity of the contrast markers on the separating direction side is smaller than bending rigidity of the contrast markers on a side where the contrast markers come close to the stent (70).