Endoscope Basket Wire Geometry for Gallstone Capture
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Solution Overview
Problem
Existing endoscope treatment tools face difficulties in capturing and removing gallstones that have become lodged in stepped portions with a lopsided structure at the boundary between the bile duct and duodenal papilla, as conventional basket-type forceps struggle to reach and retrieve such stones effectively.
Innovation Solution
An endoscope treatment tool featuring a basket portion formed by elastic wires with a unique configuration, including a maximum-outer-diameter portion and a largest portion, which allows for enhanced expansion and contraction to reach and capture gallstones in complex bile duct structures, combined with a support member and manipulation wire for precise movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional basket-type forceps is used, then the structure is simple and easy to manufacture, but it cannot reach small gallstones in stepped portions effectively
Solution Approach 1:
The basket portion is divided into multiple elastic wires (first elastic wire, second elastic wire, etc.) that can independently expand and contract. Each wire can be manipulated separately to reach into stepped portions and capture gallstones, while the entire basket can be controlled through the manipulation wire for retrieval.
Solution Approach 2:
The basket portion is designed with dynamic expandability and contractability through elastic wires. The basket can expand to access gallstones in stepped portions and contract for retrieval, transforming from a static structure to a dynamic one that adapts to different anatomical conditions.
2Strength
If the basket portion is made with larger wires for strength, then the structural strength is improved, but the ability to reach into tight stepped portions is reduced
Solution Approach 1:
Different portions of the basket have different wire configurations. The elastic wires are arranged to provide localized strength where needed while maintaining flexibility in other areas. The basket can locally adapt its structure to reach into stepped portions while maintaining overall structural integrity.
3Ease of manufacture
If a balloon catheter is used to press gallstones against the bile duct wall, then the method is simple, but it cannot remove gallstones from stepped portions
Solution Approach 1:
The basket portion acts as an intermediary tool between the manipulation wire and the gallstone. It can be advanced through the bile duct, expanded to reach stepped portions, capture gallstones, and then retrieved, serving as a mediating mechanism that enables gallstone removal in locations inaccessible to simple pressing methods.
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 tool enables reliable capture and removal of gallstones from stepped portions by adjusting its diameter and shape to accommodate stones in tight spaces, improving the effectiveness of gallstone retrieval in challenging bile duct geometries.
Implementation Method 1
a basket portion (4) that is configured to protrude from the lumen (2a) of the sheath (2) and that is formed of at least one elastic wire (4a)
Data Source
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AI summary
For the purpose of more reliably capturing and removing even a gallstone that has gotten into a stepped portion formed in a lopsided manner at a boundary between the bile duct and the duodenal papilla, an endoscope treatment tool according to the present invention includes: a sheath having a lumen (2a) that extends along a longitudinal axis thereof; a basket portion (4) that is configured to protrude from the lumen (2a) and that is formed of at least one elastic wire (4a); and a manipulation wire (5) that causes the basket portion (4) to be moved forward and backward, wherein the elastic wire (4a) has a maximum-outer-diameter portion (P1) between a distal end and a proximal end of the elastic wire (4a) and a largest portion (P2) that, between the maximum-outer-diameter portion (P2) and the proximal end of the elastic wire (4a), reaches the maximum size in an opposite direction from maximum-outer-diameter portion (P1) in a side view from a direction that is orthogonal to a perpendicular line (Lv) drawn to a center axis (O) from the maximum-outer-diameter portion (P1), and wherein, in a front view of the basket portion (4), the largest portion (P2) is positioned on an opposite side from the side of the maximum-outer-diameter portion (P1) with respect to a straight line that is orthogonal to the perpendicular line (Lv) on the center axis (O).