Trocar Retaining Mechanism Cam Wire Locking

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Solution Overview

Problem

Current surgical stapling devices lack an effective retaining mechanism to securely and releasably attach a trocar assembly within a reusable adapter assembly, making it difficult to clean and sterilize the adapter assembly for reuse.

Innovation Solution

A retaining mechanism is introduced, comprising a cam wire and retaining members with chamfered portions, allowing for secure locking and easy release of the trocar assembly within the adapter assembly, facilitating cleaning and reuse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the trocar assembly is permanently fixed within the adapter assembly, then the structural stability and reliability are improved, but the ease of cleaning and sterilization deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidease of cleaning and sterilization
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The retaining mechanism is divided into separate components: retaining members with cutouts, a cam wire, and a retaining block. These segmented parts can be easily disassembled and reassembled, allowing the trocar assembly to be securely fixed when needed and easily removed for cleaning and sterilization when required.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining mechanism transitions from a static fixed state to a dynamic removable state through the cam wire actuation. The cam wire can be moved between positions to engage or disengage the retaining members, enabling the system to adapt between secure fixation and easy removal based on operational needs.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a complex retaining mechanism is used to securely attach the trocar assembly, then the reliability of secure attachment is improved, but the device complexity increases

Engineering Contradiction:
Improvesecure attachmentVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cam wire mechanism utilizes the natural cam action and geometry of the cutouts to automatically engage and lock the retaining members into place. The design self-regulates through the interaction of the cam wire's angled surface with the cutout features, eliminating the need for additional springs, actuators, or complex control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The retaining block serves as an intermediary component that mediates between the cam wire and the retaining members. It provides a simple interface that translates the cam wire's linear movement into the rotational or linear engagement of the retaining members, simplifying the overall mechanism while ensuring reliable attachment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the retaining members are fully received within the openings for secure locking, then the reliability of retention is improved, but the ease of release and removal deteriorates

Engineering Contradiction:
Improveretention reliabilityVSAvoidease of release
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cutouts in the retaining members are pre-configured with specific geometries that guide the cam wire's movement. The angled surfaces and transitions in the cutouts are designed in advance to facilitate smooth engagement during locking and easy disengagement during release, eliminating the need for complex release mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of requiring a complex unlocking mechanism to release the retaining members, the design uses the inverse approach: a simple cam wire movement in one direction locks the members securely, while moving the cam wire in the opposite direction automatically releases them. This inversion of the locking and releasing actions simplifies the release process while maintaining secure retention.

Inventive Principle:
Principle #13The other way round (Inversion)

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

The mechanism ensures secure attachment and easy release of the trocar assembly, enabling effective cleaning and sterilization of the adapter assembly, thereby enhancing the device's reusability and hygiene.

Implementation Method 1

a cam wire moveably positioned relative to the retaining block between a lock position and a release position

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The retaining members each include a locking portion, an end surface of the locking portion having first and second chamfered portions. The first and second chamfered portions may facilitate reception of the pair of retaining members within the pair of openings in the trocar housing.

Methodology Applied
Scientific EffectMechanical Fastener: Mechanical Fastener

Data Source

PatentEP3782560B1Retaining mechanisms for trocar assembly
Publication Date: 2024.01.10 COVIDIEN LP
  • EP3782560B1 patent drawingFigure 1
  • EP3782560B1 patent drawingFigure 2
  • EP3782560B1 patent drawingFigure 3

AI summary

A retaining mechanism for releasably securing a trocar assembly within an outer sleeve of an adapter assembly includes a retaining block, a cam wire moveably positioned relative to the retaining block between a lock position and a release position, a retaining block extension maintaining the cam wire relative to the retaining block, a button member in operable engagement with the cam wire, and a pair of retaining members moveable from a first position received within first and second openings of the trocar assembly when the cam wire is in the lock position and a second position spaced from the trocar assembly when the cam wire is in the release position. The retaining members each define a cutout having first and second stepped cutout portions and a smooth transition between the first and second stepped cutouts for receiving the cam wire.