Anvil Assembly Snap Backup Ring Retention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing tiltable anvil assemblies in circular anastomosis staplers face issues where the backup member may return to its proximal position due to residual force, preventing the anvil head from tilting during stapling, as the deformable tabs used for retention may stick to the knife blade or fail to maintain the distal position effectively.

Innovation Solution

An anvil assembly with a center rod assembly and a head assembly that includes a backup member with first and second locking features, which are configured to engage with a post's annular grooves, allowing the backup member to move from a proximal to a distal position upon application of a predetermined force, ensuring the anvil head can tilt by disengaging from a tab and aligning with a distal groove for secure retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If deformable tabs are used to retain the backup member in the proximal position, then the backup member can be held securely before firing, but the tabs may stick to the knife blade or fail to maintain the distal position after firing

Engineering Contradiction:

Improvebackup member retentionVSAvoidbackup member movement

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The backup member is designed with dynamic retention features that change state based on operational phase. The locking features engage with annular grooves to provide stable retention in both proximal and distal positions, while the deformable tabs provide controlled flexibility during the transition phase, allowing reliable movement from proximal to distal position while maintaining secure retention in both states

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The retention mechanism utilizes changes in physical parameters of the deformable tabs - specifically their deformation state. The tabs deform under predetermined force to allow movement from proximal to distal position, then maintain the new position through geometric engagement with annular grooves, changing from a flexible retention state to a rigid locked state

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the backup member is allowed to move to the distal position to permit tilting, then the anvil head can tilt during stapling, but the backup member may return to the proximal position due to residual force

Engineering Contradiction:

Improveanvil head tiltingVSAvoidbackup member position stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The annular grooves are pre-positioned in the post at specific locations corresponding to the proximal and distal positions. The locking features on the backup member are designed to engage these pre-positioned grooves, ensuring that when the backup member reaches the distal position during firing, it automatically locks into place and cannot return to the proximal position due to residual forces

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The annular grooves act as intermediary retention points between the locking features of the backup member and the post. These grooves provide stable engagement points that mediate the interaction, ensuring the backup member remains securely held in the distal position while allowing the anvil head to tilt freely

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If locking features are added to the backup member to engage with annular grooves, then the backup member can be reliably retained in both positions, but the device complexity increases

Engineering Contradiction:

Improvebackup member position retentionVSAvoidretention mechanism structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The retention mechanism is segmented into distinct functional elements: locking features on the backup member and corresponding annular grooves on the post. This segmentation allows each element to perform its specific function independently - the locking features provide engagement while the grooves provide retention - resulting in a reliable system that achieves robust position retention through modular, manageable components rather than a single complex mechanism

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 effectively retains the backup member in the distal position post-firing, allowing the anvil assembly to tilt reliably, preventing premature return to the proximal position and ensuring consistent stapling performance.

Implementation Method 1

The retainer member includes a plurality of deformable tabs which prevent distal movement of the backup member until a predetermined force sufficient to deform the tabs is applied to the backup member

Methodology Applied

Scientific EffectDeformation: Deformation

Implementation Method 2

The backup member includes a locking feature receivable within the proximal annular groove of the post to maintain the backup member in the first position

Methodology Applied

Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentUS11540834B2Anvil assembly with snap backup ring

Publication Date: 2023.01.03 COVIDIEN LP

AI summary

An anvil assembly is provided. The anvil assembly includes center rod assembly, a head assembly pivotal relative to the center rod assembly between an operative position and a tilted position, and a mechanism for selectively maintaining the head assembly in the operative position.