Articulation Assembly Asymmetric Links Surgical Tool Positioning
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Solution Overview
Problem
Non-invasive surgical procedures, particularly in the gastrointestinal tract, face challenges in manipulating surgical tools to precise locations due to the tool's flexible shaft length and the need to navigate to regions not in-line with the entry point, requiring advanced articulation mechanisms for effective positioning.
Innovation Solution
An elongate articulation assembly with asymmetric link sections and a cable system that allows for controlled pivoting, enabling the tool to be positioned at various angles and planes, including orthogonal configurations, with adjustable angular positioning of the distal-end fitting for precise tool placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a flexible shaft is used to access the gastrointestinal tract, then the tool can reach distant target sites, but the tool cannot be precisely positioned at regions not in-line with the entry point
Solution Approach 1:
The flexible shaft is divided into multiple articulated sections with joints that can pivot relative to each other. Each section can be independently controlled to change the overall configuration of the shaft, allowing the distal end to reach target sites that are not in-line with the entry point while maintaining precise positioning capability
Solution Approach 2:
The shaft incorporates dynamic articulation mechanisms that allow it to change its configuration from straight to curved as needed. The articulated sections can pivot to form curves in different planes, enabling the tool to navigate complex anatomical pathways and position the distal end at various angles relative to the entry point
2Length of moving object
If the shaft is made longer to reach distant targets, then access to remote sites is improved, but control and manipulation of the tool becomes more difficult
Solution Approach 1:
The long shaft is segmented into multiple controllable sections, each with its own articulation joints. This allows the operator to control each section independently, maintaining manageable control complexity even as the overall shaft length increases to reach distant targets
Solution Approach 2:
The articulation mechanism allows the shaft to curve in multiple planes (different dimensions), enabling the distal end to reach targets in three-dimensional space. This multi-planar articulation provides comprehensive positioning capability without requiring excessive shaft length in a single direction
3Ease of manufacture
If symmetric pivot angles are used in all links, then the assembly is simpler to manufacture, but the tool cannot achieve precise angular positioning in specific directions
Solution Approach 1:
Different links in the articulation assembly have different pivot angle characteristics tailored to their specific functions. Some links have smaller pivot angles in one direction for precision positioning, while others have larger pivot angles for navigating sharp anatomical angles. This local customization of pivot angles achieves precise angular positioning without requiring all links to be identical
Solution Approach 2:
The articulation assembly incorporates asymmetric links with different pivot angles in different directions. This asymmetry allows the tool to achieve precise positioning in specific directions while maintaining the ability to navigate complex anatomical pathways, resolving the contradiction between manufacturing simplicity and positioning precision
Data Source
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AI summary
A device for use in guiding the position of a surgical tool from a remote location is disclosed. The device includes a handle, an elongate shaft mounted on the handle, an elongate articulation assembly carried at its proximal end to the shaft and adapted to receive the surgical tool at the assembly's distal end, and a cable operatively connecting the handle to the articulation assembly. The position of the articulation assembly is controlled by rotating a knob on the handle, which moves the articulation into different angled configurations depending on whether the knob is rotated in clockwise or counterclockwise directions.