Removable Vena Cava Filter With Asymmetric Wings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vena cava filters often become tilted or off-centered, leading to endothelialization and permanent implantation, making them difficult to remove without causing trauma to the patient.
Innovation Solution
A removable vena cava filter design featuring a hub with filter struts and wire loops that extend radially and longitudinally, preventing tilting and facilitating easy retrieval using a retrieval sheath and snaring mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional filters are deployed in the vena cava, then they can capture blood clots, but they become tilted or off-centered leading to endothelialization and permanent implantation
Solution Approach 1:
The filter employs asymmetric wing structures that extend laterally from the filter body at specific angles. These wings are positioned to engage with the vessel wall in a way that prevents tilting and maintains central alignment within the vena cava, thereby preventing endothelialization while ensuring stable clot capture
Solution Approach 2:
The filter is designed with self-centering features that automatically align the filter hub with the vessel axis during deployment. The wings are pre-configured to engage the vessel wall in a manner that preemptively prevents tilting before endothelialization can occur, ensuring long-term retrievability
2Duration of action of moving object
If filters remain in the vessel for extended periods, then they can continue to capture clots, but intimal cells accumulate around the filter parts contacting the vessel wall preventing removal
Solution Approach 1:
The filter design extracts the problematic contact points between the filter body and vessel wall by using wings that engage the vessel wall while leaving the filter hub and retrieval mechanism suspended in the vessel lumen. This separation prevents intimal cell accumulation on the retrieval components, enabling removal even after extended periods
Solution Approach 2:
The filter is segmented into distinct functional zones: the wings contact the vessel wall for stabilization, while the hub and retrieval hook remain in the lumen. This segmentation isolates the retrieval mechanism from endothelialization, allowing for safe removal after prolonged implantation
3Stability of the object's composition
If the filter hub and retrieval hook engage the vessel wall along their lengths, then the filter becomes stable, but it becomes endothelialized and permanently implanted
Solution Approach 1:
Only specific localized portions of the filter (the wings) are designed to engage the vessel wall, while the hub and retrieval hook remain non-contacting. This localized engagement provides stability without causing widespread endothelialization or trauma to the vessel wall
Data Source
AI summary
A filter device has a single hub and a plurality of filter struts extending in a first longitudinal direction. A plurality of wire loops extend in a second longitudinal direction opposite the filter struts. The filter struts and wire loops each engage the vessel wall of a body lumen when deployed. The wire loops limit the filter device from becoming tilted and embedded in the vessel wall. A retrieval device includes a sheath and a snaring mechanism. The snaring mechanism engages a hook member of the filter and the sheath envelopes the wire loops and filter struts. The sheath will cause the wire loops to bend and fold over the filter struts during retrieval such that the wire loops and filter struts extend in the same longitudinal direction after being enveloped by the sheath.