Elastic Band Ligation Device Locking Mechanism

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Solution Overview

Problem

Existing elastic band ligation devices for hemorrhoid treatment suffer from premature deployment of the elastic band, leading to delays and increased patient discomfort due to the lack of control over the deployment timing.

Innovation Solution

An elastic band ligation device with a locking mechanism, including a manually actuated tab on the outer tubular pusher sleeve, which prevents relative movement between the outer and inner tubular members until intentionally unlocked by the user, ensuring controlled deployment of the elastic band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the outer tubular pusher sleeve is designed to move freely over the inner tubular member, then the elastic band can be deployed easily, but premature deployment occurs causing delays and patient discomfort

Engineering Contradiction:

Improveease of elastic band deploymentVSAvoidcontrol over deployment timing

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The locking mechanism applies a preliminary restraining force to the outer tubular pusher sleeve through the frangible connection, preventing any unintended movement that could cause premature band deployment. This counter-action ensures the sleeve remains stationary until the operator intentionally activates the release mechanism.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The system transitions from a static locked state to a dynamic deployed state through a controlled mechanism. The frangible connection allows the outer sleeve to move only when a specific activation force is applied to the tab, providing dynamic control over the deployment timing while maintaining reliability.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the locking mechanism is made robust to prevent premature deployment, then deployment control is improved, but the device complexity increases

Engineering Contradiction:

Improveprevention of premature deploymentVSAvoidcomplexity of locking mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is segmented into distinct functional components: the tab for activation, the frangible connection for controlled release, and the outer tubular pusher sleeve for deployment action. This segmentation allows each component to perform its specific function simply, reducing overall complexity while maintaining reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The frangible connection acts as an intermediary element between the tab and the outer tubular pusher sleeve. It provides a controlled release mechanism that is simpler than a full mechanical locking system, reducing complexity while ensuring reliable prevention of premature deployment.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the frangible connection is made strong to prevent accidental release, then deployment control is improved, but intentional release becomes more difficult

Engineering Contradiction:

Improveprevention of accidental tab releaseVSAvoidease of intentional band deployment

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The frangible connection is pre-designed with specific mechanical properties that allow it to resist accidental forces during normal operation but fail easily when a specific activation force is applied to the tab. This preliminary preparation ensures both reliability and ease of intentional deployment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The frangible connection's mechanical strength parameters are optimized to be high enough to prevent accidental release during insertion and positioning, but low enough to allow easy release when the tab is intentionally activated. This parameter optimization resolves the contradiction between strength and ease of release.

Inventive Principle:

Principle #35Parameter changes

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

This solution provides precise control over the deployment of the elastic band, reducing the need for re-loading and minimizing patient discomfort by preventing premature deployment, thus enhancing the efficiency and smoothness of the banding procedure.

Implementation Method 1

the handle for sliding the plunger away from the front end of the inner tubular member to provide a suction for drawing hemorrhoidal tissue into the inner tubular member

Methodology Applied

Scientific EffectSuction: Suction

Implementation Method 2

an outer tubular pusher sleeve configured to provide a limited friction fit over the inner tubular member

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9622750B2Elastic band ligation device with locking mechanism and method for treatment of hemorrhoids

Publication Date: 2017.04.18 CRH MEDICAL CORP

AI summary

Elastic band ligation device for treating hemorrhoidal tissue, including an inner tube for retaining an elastic band, a plunger in the inner tube for drawing hemorrhoidal tissue into the inner tube, and an outer tube pusher sleeve disposed over the inner tube. A thumb pusher on the sleeve allows the operator to push the sleeve towards the front of the inner tube to deploy the elastic band from the front end of the inner tube onto hemorrhoidal tissue drawn into the inner tube. The sleeve has a locking mechanism including a tab for locking the sleeve to the inner tube to prevent relative movement of the sleeve and inner tube until the sleeve is unlocked by the user, thereby preventing premature deployment of an elastic band.