Hybrid Ball Joint Structure for Precise Surgical Shaft Articulation

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Solution Overview

Problem

Robotic surgical systems face challenges in articulating surgical forceps due to the complexity of guiding articulation cables and internal components through the shaft, which affects the precise orientation and operation of jaw members for tissue treatment.

Innovation Solution

An articulating surgical instrument featuring a ball joint with opposing spherical segments and casings that allow articulation cables to move from zero to sixty degrees, guiding actuation and electrical components without interference, and resisting rotation when cables are taught, facilitating precise control and efficient articulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If traditional articulation mechanisms are used with multiple components and cables, then articulation function is achieved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvearticulation mechanism complexityVSAvoidarticulation function
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines multiple articulation functions into a single ball joint mechanism. The ball joint integrates cable routing channels, articulation movement, and component guidance into one unified structure, eliminating the need for separate articulation mechanisms and reducing overall device complexity while maintaining reliable articulation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ball joint serves multiple functions simultaneously: it enables articulation movement, guides articulation cables through its channels, supports actuation components, and provides structural connection between shaft segments. This multi-functionality reduces the number of separate components needed and simplifies the overall articulation system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If articulation cables are routed through complex pathways, then articulation is achieved, but manufacturing precision and assembly difficulty increase

Engineering Contradiction:
Improvecable routing easeVSAvoidcable alignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The ball joint is pre-designed with integrated cable channels that define the exact routing path for articulation cables. This preliminary structuring of cable pathways during manufacturing eliminates the need for complex post-assembly cable routing and ensures precise cable alignment without requiring high manufacturing precision for separate cable guides.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If a single ball joint is used for sixty-degree articulation, then device simplicity is improved, but articulation precision may be compromised

Engineering Contradiction:
Improvearticulation mechanism complexityVSAvoidarticulation angle precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The ball joint is designed to dynamically accommodate articulation movement through its spherical geometry, allowing smooth rotation and positioning. The channels within the ball joint adapt to the articulation angle, maintaining cable tension and alignment throughout the sixty-degree range of motion while preserving articulation precision through the inherent dynamics of spherical movement.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4173584A1Hybrid ball joint for articulation shaft of a surgical instrument
Publication Date: 2023.05.03 COVIDIEN LP
  • EP4173584A1 patent drawingFigure 1
  • EP4173584A1 patent drawingFigure 2
  • EP4173584A1 patent drawingFigure 3

AI summary

An articulating surgical instrument includes a housing having a shaft extending therefrom, the shaft having a proximal segment and a distal segment separated by an articulation section configured to articulate the distal segment relative to the proximal segment upon actuation thereof. The articulating section includes: a ball joint having a plurality of opposing spherical segments, each adjacent pair of spherical segments defining a channel therebetween configured to receive an articulation cable therethrough, each channel including an angled surface on opposing sides thereof to allow articulation of each cable along a respective length thereof; and a pair of casings configured to operably receive and retain the ball joint on opposing ends thereof, each casing including a chamfer defined therein configured to rotationally receive an end of the ball joint therein, each casing including a corresponding number of apertures defined therein each configured to receive a respective articulation cable therethrough.