Articulation Screw and Nut Mechanism for Surgical End Effector Control

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Solution Overview

Problem

Existing surgical instruments lack a robust and efficient mechanism for articulating surgical end effectors between parallel and non-parallel orientations, which is essential for precise surgical procedures, and often require complex and costly proprietary drive systems.

Innovation Solution

A hand-held surgical instrument featuring a handle housing with an articulation screw and nut system, where the articulation nut is rotatably supported and threadedly coupled to the articulation screw, allowing for manual or motor-driven articulation of the surgical end effector between parallel and non-parallel orientations, integrated with a fire assembly for stapling functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a proprietary drive system is used to articulate the surgical end effector, then articulation functionality is achieved, but device complexity and cost increase

Engineering Contradiction:

Improvearticulation functionalityVSAvoiddrive system complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The articulation mechanism is segmented into distinct functional components: an articulation screw for linear motion, an articulation nut for rotational motion, and an articulation link for transferring motion to the end effector. This segmentation allows each component to perform its specific function independently, simplifying the overall drive system while maintaining articulation capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The articulation link serves as an intermediary element that connects the articulation screw to the surgical end effector. It transfers the linear motion generated by the screw-nut mechanism into the desired articulation motion of the end effector, enabling complex motion control through a simplified intermediate mechanism.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If a complex proprietary drive system is implemented, then articulation precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improvearticulation precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces complex electronic or motorized drive systems with a purely mechanical screw-nut articulation mechanism. This mechanical substitution reduces manufacturing costs by eliminating motors, controllers, and electronic components while maintaining articulation precision through the inherent precision of threaded mechanical connections.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The articulation precision is controlled by changing mechanical parameters such as the thread pitch of the articulation screw and the gear ratio between the articulation nut and screw. These parameter adjustments allow for precise articulation angles to be achieved through simple mechanical modifications rather than complex electronic control systems.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If manual articulation control is used, then device complexity is reduced, but articulation speed decreases

Engineering Contradiction:

Improvedrive system complexityVSAvoidarticulation speed

Core Design Contradiction:

Device complexityVSSpeed

Solution Approach 1:

The articulation system is designed to be dynamically adaptable, allowing the surgeon to switch between manual control for precision and motorized actuation for speed. The mechanical screw-nut mechanism provides immediate mechanical feedback and control, while the option for motorized actuation is integrated to provide rapid articulation when needed, thus meeting different operational requirements without permanently increasing system complexity.

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 precise and efficient articulation of surgical end effectors, simplifies the drive system, and allows for both manual and motor-powered operation, enhancing surgical precision and reducing complexity and costs.

Implementation Method 1

The articulation screw is configured to translate in response to a rotation of the articulation nut, whereby the articulation screw articulates the surgical end effector between a parallel orientation relative to the shaft portion and a non-parallel orientation relative to the shaft portion

Methodology Applied

Scientific EffectScrew mechanism: Screw

Data Source

PatentUS11510669B2Hand-held surgical instruments

Publication Date: 2022.11.29 COVIDIEN LP

AI summary

A hand-held surgical instrument includes a handle housing, an elongated shaft portion configured to extend distally relative to the handle housing, and a surgical end effector configured to be coupled to a distal end portion of the shaft portion. An articulation screw is operably coupled to the surgical end effector, and an articulation nut is disposed about and operably coupled to the articulation screw. The articulation screw is configured to translate in response to a rotation of the articulation nut, whereby the articulation screw articulates the surgical end effector between a parallel orientation relative to the shaft portion and a non-parallel orientation relative to the shaft portion.