Vena Cava Filter Bending Structure for Vessel-Safe Retrieval
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Solution Overview
Problem
Existing vena cava filters are inconvenient to remove without damaging blood vessel intima and pose risks of thrombosis, deformation, tilt, and penetration due to long-term implantation.
Innovation Solution
A filter design with a main body part, connecting segments, and support parts, featuring a bending part on the connecting segments and a flexible part on the filter mesh to avoid vessel contact, reduce stress concentration, and delay endothelial cell growth, facilitating easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the filter is implanted into the blood vessel for long-term use, then the filter can continuously prevent pulmonary embolism, but the filter may be crawled and wrapped by endothelial cells, causing damage to the blood vessel intima during removal
Solution Approach 1:
The filter is divided into a main body part and multiple connecting segments. The connecting segments are separable from the main body, allowing the filter to be divided into removable parts. This segmentation enables the filter to maintain its function during implantation while facilitating convenient removal by separating the connecting segments from the main body, thereby avoiding damage to the blood vessel intima.
Solution Approach 2:
The connecting segments are designed with dynamic characteristics, allowing them to be flexible during implantation to adapt to the blood vessel shape, but can be easily detached when removal is needed. The connecting segments can deform and adjust during implantation, then be separated when removal is required, providing dynamic adaptability that solves both long-term reliability and ease of removal.
2Reliability
If the filter is implanted for long-term use, then continuous protection against pulmonary embolism is achieved, but risks of thrombosis, venous blockage, and pulmonary embolism recurrence increase due to protein adsorption and platelet adhesion
Solution Approach 1:
The connecting segments are extracted as separate, removable components from the filter structure. By removing the connecting segments after the acute phase of deep venous thrombosis, the filter can be partially or fully removed, reducing the long-term presence of foreign material in the blood vessel. This extraction principle reduces the continuous risk of protein adsorption, platelet adhesion, and thrombosis while maintaining protection during the critical period.
Solution Approach 2:
The filter is designed as a temporary, disposable device intended for use during the acute phase of deep venous thrombosis. The connecting segments are designed to be removed after serving their protective function, rather than being permanent implants. This approach reduces long-term harmful effects while providing necessary protection when most needed.
3Ease of manufacture
If the connecting segments are made straight for simple structure, then manufacturing is easier, but stress concentrates at the connection between the first filter mesh and the connecting segments, reducing filter stability
Solution Approach 1:
The connecting segments are designed with curved or bent configurations instead of straight lines. The bending parts create smooth transitions that distribute stress along the curved path rather than concentrating it at sharp corners or direct connections. This curvature principle maintains structural stability while remaining manufacturable through standard forming processes.
Solution Approach 2:
The connecting segments extend in multiple dimensions rather than simple straight lines. By adding dimensional complexity with bent configurations, the structure distributes mechanical loads across multiple spatial paths, reducing stress concentration at any single point while maintaining manufacturability through standard forming techniques.
4Productivity
If the first filter mesh is positioned close to the blood vessel wall for effective filtration, then filtration efficiency is improved, but the filter mesh contacts the inner wall of the blood vessel, facilitating endothelial cell growth and making removal difficult
Solution Approach 1:
The filter is segmented into a main body with filter mesh and separate connecting segments. The connecting segments act as spacers that maintain distance between the main body and the blood vessel wall. This segmentation allows the filter mesh to remain close enough for effective filtration while the connecting segments prevent direct contact that would facilitate endothelial cell growth, enabling easier removal later.
Solution Approach 2:
The connecting segments serve as intermediary elements between the main body and the blood vessel wall. These intermediaries maintain the necessary spacing to prevent direct contact between the filter mesh and the vessel wall, reducing endothelial cell growth while still allowing effective filtration. The connecting segments mediate the relationship between filtration efficiency and ease of removal.
Data Source
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AI summary
A filter , comprising a main body part . The main body part comprises a heart-proximal end , a plurality of connecting segments , and a first filter mesh connecting between the heart-proximal end and the plurality of connecting segments . An end of the connecting segments that is connected to the first filter mesh is bent towards a central longitudinal axis of the filter to form a bending part. A vertical distance between a proximal end of the bending part and the central longitudinal axis of the filter is less than a vertical distance between a distal end of the bending part and the central longitudinal axis of the filter .