Diagonal Closed-Cell Retrieval Devices for Tortuous Bodily Ducts
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Solution Overview
Problem
Existing retrieval devices for removing obstructions from bodily ducts, such as blood vessels and urinary tracts, face challenges in capturing and navigating through tortuous pathways, leading to potential dislodgment of obstructions and device buckling, especially in tight bends.
Innovation Solution
The devices feature a cylindrical body with a plurality of closed cell structures arranged in diagonal rows, separated by multiple diagonal rows at the same circumferential location to enhance capture and navigation, along with strategically aligned and partially straight struts for enhanced stiffness and flexibility, and a radiopaque marker for visualization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the retrieval device uses a standard cylindrical structure with uniform cell structures, then the device is easy to manufacture, but the device cannot securely capture obstructions in tortuous pathways and is prone to dislodgment and buckling
Solution Approach 1:
The cylindrical body is segmented into multiple cell structures arranged in diagonal rows, where each cell structure comprises struts forming a cage-like configuration. This segmentation allows the device to maintain structural integrity while adapting to tortuous pathways, securing the obstruction without dislodgment.
Solution Approach 2:
The cell structures are arranged asymmetrically in diagonal rows rather than uniform concentric circles, with struts positioned at specific circumferential locations. This asymmetric arrangement enhances the device's ability to navigate tortuous pathways while maintaining capture security.
2Strength
If the retrieval device uses curved struts throughout, then the device is flexible for navigation, but the device lacks stiffness and is prone to buckling in tight bends
Solution Approach 1:
Different portions of the struts have different curvatures - proximal and distal end portions are curved to provide flexibility for navigation, while mid-portions are straight to provide stiffness and prevent buckling. This local differentiation of structural properties allows the device to simultaneously achieve flexibility and strength.
3Reliability
If the cell structures are closely spaced, then the device has better obstruction capture, but the device cannot navigate tight bends without buckling
Solution Approach 1:
The cell structures are arranged in diagonal rows around the longitudinal axis, creating a three-dimensional configuration that optimizes both capture surface area and structural flexibility. This diagonal arrangement allows the device to maintain capture effectiveness while adapting to tortuous pathways.
4Ease of operation
If the struts are entirely straight, then the device maintains structural integrity, but the device cannot navigate tortuous pathways
Solution Approach 1:
The struts incorporate curved end portions for navigation flexibility while maintaining straight mid-portions for structural integrity. This localized curvature allows the device to navigate tortuous pathways without compromising overall structural stability.
Data Source
AI summary
A device for capturing and removing an obstruction in a bodily duct of a patient. The device includes a cylindrical body having a circumference and a longitudinal axis. According to some implementations the cylindrical body is comprised of a plurality of closed cell structures arranged in diagonal rows around the longitudinal axis. At least some of closed cell structures have substantially the same shape and size. According to some implementations at least some of the closed cell structures of substantially the same shape and size occupy a same circumferential location in the cylindrical body and are longitudinally separated from one another by no less than two, three, four or more diagonal rows of closed cell structures. According to other implementations the closed cell structures include diagonally extending struts having at least a curve portion and a straight portion.