Vein Filter with Central Clot Routing and Atraumatic Hooks
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Solution Overview
Problem
Current vein filters for preventing pulmonary embolism are invasive, pose risks due to major surgery, and have limitations in anchoring, deployment, and removal, with existing designs either causing vessel damage or requiring lengthy recovery times.
Innovation Solution
A vein filter with a first region for directing particles to the center of the filter and a second region for secure anchoring, featuring hooks with a penetrating tip and heel for atraumatic engagement and easy removal, made from shape memory materials for collapsible and expandable configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If major surgery with ligatures or clips is used to block blood clots, then the filter effectiveness is improved, but the invasiveness and patient trauma increase significantly
Solution Approach 1:
The filter is divided into multiple struts (typically 6) that can be independently deployed and positioned. Each strut can be controlled separately during deployment, allowing for precise placement and reducing the risk of complications while maintaining effective clot blocking capability.
Solution Approach 2:
The filter struts are nested within a delivery catheter in a collapsed state during insertion. Once positioned in the inferior vena cava, the struts are deployed outward from the catheter to their expanded filtering configuration. This nesting allows minimally invasive insertion through small venous access sites without requiring major surgical incisions.
2Stability of the object's composition
If filters with anchors embedding in vessel wall are used, then the anchoring force is improved, but the vessel wall damage increases
Solution Approach 1:
The filter incorporates a retrieval mechanism that allows transition from a permanently anchored state to a removable state. The retrieval catheter can engage with the filter struts and pull them back into the delivery catheter for removal. This dynamic capability allows the filter to be temporarily anchored during use but easily removed when no longer needed, avoiding permanent vessel wall damage.
3Reliability
If filters with complex deployment mechanisms are used, then the anchoring reliability is improved, but the device complexity increases
Solution Approach 1:
The filter incorporates multiple functions into the struts themselves: filtering capability through the strut geometry, anchoring through the expansion mechanism, and retrieval through engagement features. The delivery catheter also serves multiple purposes: protecting the collapsed filter during insertion, providing the expansion force, and enabling retrieval. This merging reduces the need for separate complex mechanisms for each function.
4Stability of the object's composition
If filters are designed for secure anchoring, then the filter stability is improved, but the ease of removal decreases
Solution Approach 1:
The retrieval catheter serves as an intermediary tool that facilitates filter removal without requiring direct manipulation of the anchored filter. The retrieval catheter engages with the filter struts through engagement features and uses its own delivery mechanism to pull the filter back into the sheath. This intermediary approach maintains filter stability during use while enabling easy removal when needed.
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 provides secure anchoring within the vessel while minimizing trauma to the vessel wall, facilitates easy deployment and removal, and enhances clot dissolution by directing clots to the center of the vessel, reducing the risk of vessel distortion and enabling minimal invasive procedures.
Implementation Method 1
made from shape memory materials for collapsible and expandable configurations
Data Source
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AI summary
A vessel filter (1010) comprises a first region (1012) and a second region (1024), the filter movable between a collapsed position for delivery to the vessel and an expanded position for placement within the vessel. The first region (1012) has a filter portion (1019) having a converging region (1022) to direct particles toward the center of the filter. The first region includes a plurality of spaced apart filter struts (1014), the struts each having a plurality of hooks (1032) at the second region. The hooks have a vessel penetrating tip (1034) and a heel (1044), the penetrating tip of one hook longitudinally aligned in the collapsed position with a portion of the heel of an adjacent hook.