Helical Basket for Endoscopic Calculus Snaring

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Solution Overview

Problem

Existing endoscope treatment tools struggle to snare foreign matter, such as calculi, in dilated bile ducts near the duodenal papilla due to a significant diameter difference, causing the basket to deform and fail to reach the calculus when retracted into the papilla.

Innovation Solution

An endoscope treatment tool featuring a pliable flexible sheath with a basket portion composed of helically wound elastic wires, where the maximum diameter portion is positioned closer to the locking portion than the intermediate position, maintaining the outside diameter even when the proximal end is reduced, allowing the basket to reach and snare calculi in dilated areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the basket is retracted into the duodenal papilla, then the basket can be inserted into the body passage, but the whole basket is reduced in size and the elastic wires do not reach the dilated portion

Engineering Contradiction:
Improvebasket insertionVSAvoidelastic wire reach
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The basket is divided into distinct functional zones: a proximal portion with larger diameter for reaching dilated sections, and a distal portion with smaller diameter for navigation. The elastic wires are segmented into different length groups, with longer wires in the proximal region and shorter wires in the distal region, allowing differential reach capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the basket have different structural properties. The proximal portion has a larger diameter and longer elastic wires to reach dilated portions, while the distal portion has a smaller diameter for easy navigation. The elastic wires are arranged with varying lengths and orientations to provide localized reach capabilities where needed.

Inventive Principle:
Principle #3Local quality

2Volume of moving object

If the basket shape is deformed to reduce overall size for retraction, then the basket fits into the papilla, but the maximum diameter portion cannot reach the dilated bile duct

Engineering Contradiction:
Improvebasket sizeVSAvoidmaximum diameter portion reach
Core Design Contradiction:
Volume of moving objectVSLength of moving object

Solution Approach 1:

The basket is divided into proximal and distal portions with different diameter characteristics. The proximal portion maintains a larger diameter to reach dilated bile duct sections, while the distal portion has a smaller diameter for navigation. This segmentation allows the basket to have non-uniform size distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The basket structure transitions from a uniform cylindrical shape to a conical or tapered shape with varying diameter along its length. This dimensional variation allows the proximal end to extend further radially to reach dilated portions while the distal end remains compact for navigation through the papilla.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 effectively snares calculi in dilated bile ducts by maintaining the maximum diameter portion's outside diameter, ensuring the basket can capture foreign matter even in areas where the prior-art baskets fail to reach, reducing the risk of losing the calculus during retrieval.

Implementation Method 1

a basket portion which is provided at a distal end of the manipulation wire, is constituted by a plurality of elastic wires, and opens and closes in a radial direction orthogonal to a central axis of the manipulation wire

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2638870B1Endoscopic treatment instrument
Publication Date: 2016.01.13 OLYMPUS CORPORATION(JP)
  • EP2638870B1 patent drawingFigure 1
  • EP2638870B1 patent drawingFigure 2
  • EP2638870B1 patent drawingFigure 3

AI summary

An endoscope treatment tool includes: a pliable flexible sheath; a manipulation wire inserted through the flexible sheath so as to freely advance and retract; a basket portion which is provided at a distal end of the manipulation wire, and is constituted by a plurality of elastic wires; and a locking portion which is provided at distal ends of the elastic wire, and integrates the plurality of elastic wires. A maximum diameter portion of the basket portion in the radial direction is at a position closer to the locking portion than an intermediate position between a proximal end of the basket portion and the locking portion in a direction of the central axis. The plurality of elastic wires is formed in a shape of a helix in which each of the plurality of elastic wires is wound in a same direction over an entire length of the plurality of elastic wires, and a winding pitch of the plurality of elastic wires becomes gradually smaller from the distal end of the manipulation wire toward the locking portion.