Circular Stapler Collar Coupling for Secure Shaft Engagement

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Solution Overview

Problem

Existing circular surgical staplers face challenges in securely coupling the stapling head assembly to the shaft assembly, which can lead to inadvertent malfunction or detachment during anastomosis procedures, affecting the reliability and precision of tissue clamping, cutting, and stapling.

Innovation Solution

The implementation of a collar with flexible tabs and a shaft assembly featuring an annular ridge or detents allows for a snap-fit engagement between the stapling head assembly and the shaft assembly, ensuring secure coupling and preventing relative movement along the longitudinal axis, thereby enhancing the stability and reliability of the surgical stapler.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional coupling mechanism is used between the stapling head assembly and shaft assembly, then the device structure is simple, but the coupling reliability is poor and detachment may occur during procedures

Engineering Contradiction:
Improvecoupling reliabilityVSAvoidcoupling mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The collar is designed with flexible tabs that can dynamically change their configuration - flexing radially outward during assembly to engage with detents, and maintaining that engaged state during operation. This dynamic behavior allows a relatively simple structure to achieve reliable, secure coupling without requiring complex fastening mechanisms.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the collar flexible tabs are spaced closely together, then the coupling is more secure, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecoupling securityVSAvoidtab spacing precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The collar is segmented into multiple flexible tabs spaced circumferentially around the collar. This segmentation allows the coupling security to be distributed across multiple engagement points rather than relying on a single complex mechanism. The tabs can be spaced at standard manufacturing intervals while collectively providing secure coupling through their combined engagement with multiple detents on the shaft assembly.

Inventive Principle:
Principle #1Segmentation

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 a secure and reliable coupling mechanism that prevents detachment and ensures precise anastomosis procedures by maintaining the stapling head assembly in a stable position relative to the shaft assembly, improving the consistency and reliability of tissue manipulation and staple formation.

Implementation Method 1

a collar having at least one latching feature, the collar defined by a plurality of circumferentially-arranged flexible tabs configured to flex radially outwardly

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4210597B1Coupling feature for circular surgical stapler end effector
Publication Date: 2024.11.13 CILAG GMBH INTERNATIONAL
  • EP4210597B1 patent drawingFigure 1
  • EP4210597B1 patent drawingFigure 2
  • EP4210597B1 patent drawingFigure 3~4

AI summary

A surgical stapling instrument includes a body member having a distal end. The distal end is configured to be fixedly secured to an annular deck member having a plurality of staple openings. The body member is configured to slidably house a staple driver member. The body member includes a radially expandable collar having at least one latching feature. The surgical stapling instrument also includes a shaft assembly, including a proximal sheath portion, a distal sheath portion, and at least one protrusion extending radially outwardly from the distal sheath portion. The at least one protrusion includes at least one abutment surface configured to engage the at least one latching feature of the radially expandable collar for coupling the body member to the shaft assembly.