Surgical End Effector Lockout for Cartridge-Dependent Jaw Clamping

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Solution Overview

Problem

Existing surgical instruments lack a mechanism to prevent accidental clamping of jaws when a staple cartridge is missing, which can lead to tissue being cut but not sealed by staples.

Innovation Solution

A surgical end effector with a lockout arrangement that prevents rotational movement of the second jaw toward the first jaw unless a staple cartridge is positioned in the first jaw, featuring a lock bar that translates to unlock the pin when the cartridge is present.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lockout arrangement is added to prevent accidental clamping, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lockout arrangement integrates the lock bar and pin mechanism within the existing jaw structure. The lock bar translates along a defined path within the jaw assembly, and the pin is positioned within the rotational path of the lock bar, creating a nested configuration where safety components are embedded within the structural components rather than added as external attachments.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The lockout arrangement is automatically actuated by the presence or absence of the staple cartridge itself. When the cartridge is installed, its physical presence drives the lock bar to the proximal position, which automatically moves the pin to unlock the jaw. When the cartridge is removed, the spring automatically returns the lock bar to the distal position, re-engaging the pin to lock the jaw. The system uses its own operational components to provide the safety function without requiring separate control mechanisms.

Inventive Principle:
Principle #25Self-service

2Reliability

If a lockout mechanism is implemented to prevent clamping without cartridge, then reliability is improved, but ease of operation deteriorates

Engineering Contradiction:
ImprovereliabilityVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The lockout mechanism is passively actuated by the natural insertion and removal of the staple cartridge. The cartridge's physical presence directly drives the lock bar through its translation path, which in turn moves the pin to the unlocked position. No separate activation step or additional user action is required - the act of installing the cartridge itself performs the unlocking function.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The spring-loaded lock bar is pre-positioned in the distal locked configuration before the cartridge is installed. This preliminary positioning ensures that the jaw is automatically locked unless the cartridge is present to drive it to the unlocked position. The system is prepared in advance to prevent accidental operation, and the unlocking action is prepared to occur automatically upon cartridge insertion.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4278988B1Lockout arrangements for surgical end effectors and replaceable tool assemblies
Publication Date: 2025.09.10 ETHICON INC
  • EP4278988B1 patent drawingFigure 1
  • EP4278988B1 patent drawingFigure 1A
  • EP4278988B1 patent drawingFigure 2

AI summary

Surgical end effectors are disclosed. The surgical end effectors can include a first jaw, a second jaw rotatably coupled to the first jaw, and a lockout arrangement configured to prevent rotational movement of the second jaw toward the first jaw unless an unfired staple cartridge is positioned in the first jaw. The lockout arrangement can comprise a pivotable lock configured to pivot between a locked orientation and an unlocked orientation, a shiftable lock bar, and/or a spring-loaded lockout lever.