Retrievable Inferior Vena Cava Filter Using Nitinol and Segmented Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current inferior vena cava filters face challenges such as secondary thrombosis, limited biocompatibility, inadequate fixation, and short implantation time, failing to meet all desired features like effective thrombus capture, stable placement, and retrievability without causing vascular occlusion or complications.
Innovation Solution
A retrievable inferior vena cava filter design featuring a retrieval hook, connecting part, and multiple support poles with spherical round heads, forming a single-layer filter net made from nickel-titanium alloy, which reduces endothelialization contact area and provides multi-point support for stable placement and easy retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the filter is made from traditional metal materials with large surface area, then the filtration effect is good, but the biocompatibility is poor and thrombus formation increases
Solution Approach 1:
The patent uses nickel-titanium alloy (nitinol) as the filter material, which combines the mechanical strength and flexibility needed for filtration with superior biocompatibility. This composite material approach allows the filter to maintain its structural integrity while reducing thrombus formation compared to traditional metal filters.
Solution Approach 2:
The filter employs a single-layer mesh structure with optimized pore size and distribution. This porous design allows blood flow through while capturing thrombi, achieving effective filtration without requiring excessive material surface area that would increase thrombus formation risk.
2Device complexity
If the filter uses simple support structure, then the device complexity is low, but the fixation stability is insufficient
Solution Approach 1:
The filter is divided into multiple segments including the main body, support poles, and retrieval hook. This segmentation allows each component to perform its specific function: the support poles provide fixation stability by anchoring into the vena cava wall, while the main body performs filtration, and the retrieval hook enables easy removal.
Solution Approach 2:
The support poles feature curved or angled configurations rather than straight rigid structures. This curvature allows the poles to better conform to the vena cava anatomy and engage with the vessel wall at optimal angles, enhancing fixation stability while maintaining structural simplicity.
3Reliability
If the filter is designed for permanent implantation, then the fixation stability is improved, but the retrievability is lost
Solution Approach 1:
The retrieval hook is extracted as a separate functional component from the filter body. This allows the filter to maintain stable fixation during implantation while enabling complete retrieval when needed. The hook engages with the delivery system for insertion and can be re-engaged for removal, providing adaptability without compromising fixation stability.
4Reliability
If the filter uses multi-layer structure, then the filtration effect is enhanced, but the endothelialization contact area increases causing more thrombus
Solution Approach 1:
The single-layer mesh structure provides adequate filtration through optimized pore geometry and size distribution. This eliminates the need for multiple layers, thereby minimizing the contact area with the vascular wall and reducing endothelialization while maintaining effective thrombus capture capability.
Data Source
AI summary
An inferior vena cava filter comprises a recovery hook (1), a connection component (12), and multiple supporting rods. The connection component (12) is disposed below the recovery hook (1), and a component connected to a push device is disposed in the connection component. Multiple first supporting rods (4) are divided from the lower part of the connection component (12). One second supporting rod (2) and two third supporting rods (5) are divided from the far end of each first supporting rod (4). One part of the far end of the second supporting rod (2) is bent to form a hook shape. The third supporting rods (5) continue to extend downwards. When expanded, the third supporting rods (5) and the third supporting rods (5) divided from the first supporting rods (4) extend in an inner arc shape, and the lower ends of the adjacent two third supporting rods (5) divided from the adjacent two first supporting rods (4) get close. When expanded, the supporting rods form a filtering net shape as a whole.