Helical-Groove Cold Snare Wire for Secure Polyp Resection
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Solution Overview
Problem
Existing snares for resecting polyps during endoscopic procedures face challenges in securely grasping and resecting the desired amount of tissue without slipping, particularly for polyps of varying sizes and shapes.
Innovation Solution
A snare wire with a helical groove design that enhances tissue engagement and reduces slippage, featuring a groove depth less than half of the cross-sectional diameter, a helix pitch of 2-3 mm, and a cross-sectional area overlap of 5-20% of the total area, allowing for secure resection of polyps ranging from 1 to 40 mm in diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional smooth snare wire is used, then the device structure is simple, but the snare wire slips and cannot securely grasp the polyp tissue
Solution Approach 1:
The snare wire incorporates grooves only at specific locations where tissue contact is needed, rather than making the entire wire complex. The grooves are strategically positioned to engage polyp tissue while maintaining a relatively simple overall wire structure, thus improving reliability without excessive complexity
Solution Approach 2:
The grooves are formed with curved or helical patterns along the snare wire surface, creating a three-dimensional engagement structure that better conforms to the cylindrical shape of polyp tissue. This curvature enhances the mechanical interlocking between the snare and tissue, preventing slippage
2Area of moving object
If a smooth snare wire is used, then the manufacturing process is simple, but the resection site area is insufficient
Solution Approach 1:
The snare wire surface is segmented into multiple grooves that create distinct engagement zones along the wire. This segmentation increases the effective surface area available for tissue contact and resection without requiring a completely different manufacturing approach, as the grooves can be added through standard machining or forming processes
Solution Approach 2:
The grooves add a third dimension to the snare wire surface by creating depth variations. This dimensional addition increases the effective resection site area by utilizing the groove volumes, allowing for greater tissue engagement while still using conventional wire fabrication methods with added machining steps
3Reliability
If a smooth snare wire is used, then the device is easy to operate, but slippage occurs during polyp resection
Solution Approach 1:
The grooves on the snare wire automatically engage with the polyp tissue through mechanical interlocking as the snare is closed around the polyp. This self-engaging feature reduces the need for precise manual manipulation to maintain grip, as the groove geometry itself provides the securing mechanism, thereby preventing slippage while maintaining ease of operation
Data Source
AI summary
A snare including a snare wire. The snare wire is formed into a loop, includes an exterior surface, and exhibits a length and a cross-section. The cross-section is orthogonal to the length. The snare wire includes a groove extending helically along the length of the snare wire. The groove is defined by an open channel including an opening defined at the exterior surface. The cross-section defines a center line and a cross-sectional length. The open channel exhibits a groove depth less than half of the cross-sectional length. The open channel is bound in the cross-section by a first line and a second line, the first line intersects the first point and the second line intersects the second point, the first line and the second line are parallel to the center line, and the first line and the second line are equidistant from the center line.