Surgical Stapler Fire Lock Preventing Unintended Firing

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Solution Overview

Problem

Surgical stapling apparatuses used in endoscopic and laparoscopic procedures often inadvertently fire when the end effector is not in the articulated position, posing a risk of unintended tissue damage.

Innovation Solution

A fire lock assembly is integrated into the surgical stapling apparatus to prevent firing when the end effector is not articulated to a predetermined angle, allowing for safe clamping and unclamping of anvil and cartridge assemblies for navigation through small diameters, and enabling firing only when the end effector is in the articulated position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the end effector is allowed to fire in any position, then the ease of operation is improved, but the reliability deteriorates due to inadvertent firing when unarticulated

Engineering Contradiction:

Improveease of firingVSAvoidrisk of inadvertent firing

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

A fire lock assembly acts as an intermediary mechanism between the trigger and the firing mechanism. The fire lock includes a fire lock member that must be in a specific articulated position to allow the trigger to fire the end effector. This intermediary prevents inadvertent firing when the end effector is unarticulated, while still allowing firing when properly articulated.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the fire lock assembly is added to prevent inadvertent firing, then the reliability is improved, but the device complexity increases

Engineering Contradiction:

Improveprevention of inadvertent firingVSAvoidstructure of fire lock assembly

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fire lock assembly is merged with the existing articulation mechanism of the end effector. The fire lock member utilizes the same articulation joint and positioning structure already present in the device, rather than adding a completely separate control system. This integration reduces the overall complexity increase while maintaining the safety function.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the end effector must be articulated to fire, then the reliability is improved, but the ease of operation worsens due to additional positioning requirements

Engineering Contradiction:

Improvecontrolled firing positionVSAvoidpositioning requirement

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The fire lock mechanism automatically detects and responds to the articulation position of the end effector. The fire lock member is mechanically linked to the articulation joint, so that when the end effector is articulated to the correct position, the fire lock automatically engages and enables firing. The system self-regulates based on its own configuration without requiring additional user actions.

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP3586768B1Articulated stapling with fire lock

Publication Date: 2024.04.03 COVIDIEN LP

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AI summary

A loading unit for a surgical stapling apparatus includes a shaft assembly, an end effector coupled to the shaft assembly, an I-beam assembly supported in the shaft assembly, and a fire lock assembly supported on the shaft assembly. The end effector is positioned to articulate relative to the shaft assembly between an unarticulated position and an articulated position. The I-beam assembly is selectively movable relative to the end effector to fire the end effector. The fire lock assembly is configured to prevent the I-beam assembly from firing the end effector when the end effector is disposed in the unarticulated position.