Articulation Mechanism for Tissue Specimen Retrieval

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Solution Overview

Problem

Minimally-invasive surgical procedures face challenges in retrieving large tissue specimens from internal body cavies due to restricted access, which often requires breaking down specimens, increasing the risk of cancer cell seeding.

Innovation Solution

The development of tissue specimen retrieval devices equipped with articulation mechanisms, including a housing, outer shaft, end effector assembly, actuator, and articulation mechanism, which allows the end effector assembly to articulate between aligned and articulated positions, facilitating the retrieval of large specimens without breaking them down.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large tissue specimen is retrieved intact through a minimally-invasive opening, then the risk of cancer cell seeding is reduced, but the restricted access prevents successful retrieval

Engineering Contradiction:

Improverisk of cancer cell seedingVSAvoidmaneuverability through restricted access

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The end effector assembly is designed with articulation capability that allows it to dynamically change its orientation and configuration. The assembly can articulate between an aligned position (for insertion through the minimally-invasive opening) and an articulated position (for manipulating and retrieving large tissue specimens within the body cavity), thereby resolving the contradiction between restricted access and the ability to maneuver large specimens.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the end effector assembly is articulated to improve maneuverability, then access to hard-to-reach areas is improved, but the device complexity increases

Engineering Contradiction:

Improvemaneuverability and visualizationVSAvoidarticulation mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The articulation mechanism is segmented into modular components including an articulation block with multiple degrees of freedom, individual articulation joints, and separate actuation systems. This segmentation allows each component to perform a specific function while collectively providing complex articulation capability, thereby reducing overall device complexity while maintaining high adaptability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The articulation mechanism employs a nested structure where the articulation block contains multiple articulation joints and actuation mechanisms within a compact form factor. This nesting approach allows the complex articulation system to be integrated into the end effector assembly without significantly increasing external dimensions or overall device complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Length of moving object

If the articulation block is retained in the first orientation during insertion, then the device profile is minimized for insertion, but the end effector assembly cannot articulate to reach target areas

Engineering Contradiction:

Improvedevice profile for insertionVSAvoidarticulation capability

Core Design Contradiction:

Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The articulation block is designed to be dynamically controllable, allowing it to switch between a constrained first orientation during insertion (minimizing device profile) and an articulated configuration during operation (maximizing reach and maneuverability). Actuation mechanisms enable the articulation block to transition between these states as needed, resolving the contradiction between compact insertion profile and articulation capability.

Inventive Principle:

Principle #15Dynamics

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

Enables the safe and intact retrieval of tissue specimens from internal body cavities, reducing the risk of cancer cell seeding and improving maneuverability and visualization during minimally-invasive surgeries.

Implementation Method 1

a spring operably associated with the articulation block and configured to bias the articulation block towards the second orientation

Methodology Applied

Scientific EffectSpring bias: Spring

Data Source

PatentUS11666351B2Articulation mechanisms for tissue specimen retrieval devices and tissue specimen retrieval devices incorporating the same

Publication Date: 2023.06.06 COVIDIEN LP

AI summary

A tissue specimen retrieval device includes a housing, an outer shaft extending from the housing, an end effector assembly extending from the outer shaft, an actuator associated with the housing, and an articulation mechanism operably coupled between the actuator and the end effector assembly. The articulation mechanism includes an articulation block supporting the end effector assembly thereon and is rotatable between first and second orientations to articulate the end effector assembly. A spring biases the articulation block towards the second orientation. An actuation sleeve is slidable relative to the articulation block, in response to actuation of the actuator, from an engaged position, wherein the actuation sleeve is disposed about and retains the articulation block in the first orientation, to a disengaged position, wherein the actuation sleeve is spaced from the articulation block such that the articulation block rotates to the second orientation to articulate the end effector assembly.