Dual-Filter Embolic Protection Device with Cinching Mechanism
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Solution Overview
Problem
During surgical interventions, there is a risk of dislodging tissue, plaque, or other masses that can form emboli, which can travel through blood vessels and cause blockages, potentially leading to life-threatening complications such as stroke, as existing technologies fail to effectively capture and remove these emboli from critical organs.
Innovation Solution
The use of a dual-filter embolic protection device comprising a proximal and distal basket, both with collapsible/expandable mesh structures, deployed via a catheter and steerable guidewire, which can be cinched to trap emboli and then retracted for safe removal, utilizing shape-memory alloys like NITINOL for structural support and expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single filter is used to capture emboli, then the device structure is simple, but the emboli may escape during device extraction
Solution Approach 1:
The patent employs a nested filter configuration where a distal filter is positioned within a proximal filter. The distal filter captures emboli at the distal site, and the proximal filter provides a secondary containment barrier. During extraction, the distal filter is cinched closed to trap emboli, then both filters work together to prevent emboli escape, resolving the contradiction between reliability and complexity through hierarchical nesting.
Solution Approach 2:
The filtration function is segmented into two distinct filters with different functions: the distal filter for initial emboli capture and the proximal filter for secondary containment and safe extraction. This segmentation allows each filter to be optimized for its specific role while working together to ensure emboli containment throughout the procedure, including during device removal.
2Reliability
If filters are made expandable to capture emboli effectively, then the filtration area increases, but the device cannot be easily removed from the body
Solution Approach 1:
The filters are designed with dynamic expandability, transitioning from a compressed delivery state to an expanded filtration state, and finally to a cinched removal state. The expandable mesh structure allows the filters to increase their surface area for effective emboli capture during the procedure, then the cinching mechanism dynamically changes the configuration to enable safe removal, resolving the contradiction between capture efficiency and ease of removal.
Solution Approach 2:
The filter structure undergoes parameter changes in its physical state: from compressed to expanded for filtration, then to cinched-closed for removal. The mesh configuration and diameter are dynamically adjusted through the cinching mechanism, allowing the same structure to optimize for both emboli capture (expanded state) and device extraction (cinched state).
3Adaptability or versatility
If a collapsible/expandable mesh structure is used, then the filter can be delivered through catheters, but the structural support during expansion is challenging
Solution Approach 1:
The filter structure utilizes composite construction combining shape-memory alloy (NITINOL) with polymeric materials. The NITINOL provides superelasticity and shape memory properties for structural support during expansion and cinching, while the polymeric mesh provides filtration functionality. This composite approach enables the filter to be delivered compressed through catheters while maintaining sufficient structural strength when expanded and cinched.
Solution Approach 2:
The shape-memory alloy undergoes parameter changes in its mechanical properties based on temperature and stress conditions. During delivery, the alloy remains in a compressed state with reduced structural resistance. Upon deployment and cinching, the material's superelastic properties activate to provide the necessary structural support for maintaining filter shape and trapping emboli, resolving the contradiction between deliverability and structural strength.
4Quantity of substance
If emboli are captured in an expanded filter, then the capture capacity is high, but the filter profile is large for body introduction
Solution Approach 1:
The filter employs dynamic size transformation, being delivered in a compressed low-profile state that minimizes the device volume for catheter introduction. Upon deployment, the filter expands to a large surface area configuration to maximize emboli capture capacity. The cinching mechanism then dynamically reduces the filter profile again by closing the mesh, allowing safe removal while maintaining high capture capacity throughout the procedure.
Solution Approach 2:
The distal filter is nested within the proximal filter during delivery, creating a compact configuration that minimizes the overall device profile for introduction through catheters. Upon deployment, both filters expand to provide large surface areas for emboli capture. The nested arrangement allows the system to achieve high capture capacity while maintaining a small delivery profile.
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
Effectively captures and removes emboli from blood vessels, reducing the risk of blockages in critical organs during and after surgical procedures, ensuring safer interventions by preventing emboli from re-entering the bloodstream during device extraction.
Implementation Method 1
utilizing shape-memory alloys like NITINOL for structural support and expansion
Data Source
AI summary
Embolic protection devices useful for filtering emboli during interventional cardiac, vascular, or other procedures are described. The device can include first and second expandable mesh filters having open and closed ends. The first filter is attached to a catheter at its closed end. The second filter is attached to a steerable guide wire at its closed end. The second filter includes a cinching wire circumferentially attached to the filter. The filters are deployed in separate vessels, such as the brachiocephalic artery and the left common carotid artery. A procedure is performed, and the filters trap any emboli travelling through the path of the filters. At the end of the procedure, the second filter is closed using the cinching wire, and retracted into the first filter. Both the first and second filters are collapsed into a sheath and removed from the body with along with any emboli trapped in the filters.