Removable Vena Cava Filter with Arcuate Struts
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Solution Overview
Problem
Existing vena cava filters often perforate vessel walls and are permanent, lacking effective features to prevent perforation and facilitate removal after the underlying medical condition has passed.
Innovation Solution
A removable vena cava filter design featuring primary and secondary struts with distal hooks that expand to engage the vessel wall, reducing the risk of perforation and allowing for retrieval, utilizing superelastic materials and a hub with a retrieval hook for safe removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional vena cava filters are designed to firmly anchor in the vessel wall, then filtering effectiveness is improved, but the risk of perforating the vessel wall increases
Solution Approach 1:
The filter is divided into multiple struts (at least three struts) that can independently engage with the vessel wall. Each strut acts as a separate anchoring element, distributing the mechanical load across multiple contact points rather than relying on a single anchoring mechanism, thereby reducing the risk of perforation while maintaining filtering effectiveness
Solution Approach 2:
The struts are designed with curved or arcuate configurations rather than straight rigid structures. This curvature allows the struts to conform to the vessel wall geometry, creating a more gradual engagement that reduces stress concentrations and minimizes perforation risk while still providing firm anchoring
2Reliability
If permanent implants are used to ensure long-term filtering, then filtering reliability is improved, but the ability to remove the device after condition resolution is lost
Solution Approach 1:
The filter transitions from a static permanent implant to a dynamic removable device. The struts are designed to be deployable and retrievable, allowing the filter to be inserted when needed and removed after the medical condition resolves. This dynamic design enables adaptation to changing patient needs while maintaining filtering reliability during the required period
Solution Approach 2:
The filter is designed as a temporary device that can be safely removed after serving its purpose. The retrieval mechanism allows the filter to be recovered and removed from the vessel, eliminating the need for permanent implantation and allowing the vessel to heal without long-term foreign material
3Ease of manufacture
If simple filter structures are used, then ease of manufacture is improved, but the capability to prevent perforation and enable removal is reduced
Solution Approach 1:
The struts are formed from flexible, superelastic materials that can be shaped into complex arcuate configurations and then retain their form when deployed. This flexibility allows the struts to conform to the vessel wall and provide secure anchoring while maintaining a relatively simple overall structure that is ease of manufacture using standard wire forming techniques
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
The filter effectively captures thrombi while minimizing vessel wall perforation risk and can be removed after the medical condition has resolved, ensuring patient safety and reducing long-term implantation complications.
Implementation Method 1
utilizing superelastic materials and a hub with a retrieval hook for safe removal
Data Source
Figure 1
Figure 2a
Figure 2b~2c
AI summary
A removable filter for capturing thrombi in a body vessel is disclosed. The filter comprises a plurality of primary struts comprising proximal and distal portions. Each proximal portion has a first end, wherein the first ends are attached together along a longitudinal axis. Each primary strut extends arcuately along the longitudinal axis and linearly radially. The distal portions of the primary struts are configured to expand in the body vessel, engaging the distal hooks with the body vessel. Each distal portion integrally extends from the proximal portion to a plurality of distal hooks. The distal hooks are substantially equal in size relative to each other.