Endoscopic Snare Wire Loop Stability via Cap Guide Member

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Solution Overview

Problem

Existing endoscopic mucosal resection devices face challenges in maintaining the shape of the snare wire loop during tissue resection, leading to incomplete or inaccurate resection due to the snare wire retracting towards the insertion portion, which can cause the loop to collapse.

Innovation Solution

A medical device featuring a cap member with a guide member that restricts the retraction of the snare wire, forming a pre-loop that is maintained within the cap member's internal space, and a restriction member that defines the snare wire's projecting direction, ensuring the loop's stability and preventing collapse during tissue resection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the snare wire is advanced through the channel for tissue resection, then the resection function is enabled, but the snare wire tends to retract toward the insertion portion causing the loop to collapse

Engineering Contradiction:

Improveloop shape maintenanceVSAvoidsnare wire retraction control

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The guide member acts as an intermediary between the snare wire and the cap member internal surface. It provides a dedicated pathway that guides the snare wire to form a stable loop while preventing unwanted retraction toward the insertion portion, thus maintaining loop shape without complicating the overall device structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The function of preventing snare wire retraction is extracted from the cap member itself and implemented through a separate guide member component. This allows the cap member to focus on its primary function of defining the resection space while the guide member specifically addresses the loop maintenance issue

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If the cap member internal space is made larger to accommodate the snare wire loop, then the loop formation is facilitated, but the device size increases

Engineering Contradiction:

Improvesnare wire loop accommodationVSAvoidcap member internal space

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

Instead of uniformly increasing the cap member internal space, the guide member creates a localized pathway with appropriate dimensions specifically where the snare wire needs to form its loop. The rest of the cap member internal space can remain compact, optimizing the balance between loop accommodation and device size

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11413061B2Medical tool for endoscope

Publication Date: 2022.08.16 OLYMPUS CORPORATION(JP)

AI summary

A medical device includes a snare wire advanceable and retractable inserted through a channel in an insertion portion that is inserted through an endoscope; a substantially tubular cap member including a first portion and a second portion connected to a distal end of the insertion portion, the cap member having an annular distal end surface, the first portion being attachable to the distal end of the insertion portion in phase with the channel, and the cap member having an internal space formed by the first portion and the second portion; and a guide member being linearly extended along an internal surface of the distal end side of the cap member at a side of the second portion, the guide member being configured to guide the snare wire to form a loop and to restrict a retraction of the snare wire toward the side of the insertion portion.