Articulating Torqueable Hollow Device Stacked Link Mechanism
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Solution Overview
Problem
Conventional flexible endoscopes face challenges such as inconsistent bending, twisting under torque, high cost, complexity, fragility, and the need for expensive maintenance and disinfection, which affect navigation, patient comfort, and risk of cross-contamination.
Innovation Solution
A low-cost, disposable articulation mechanism for endoscopes featuring stacked links with tapered and wedge-shaped recesses for precise control of deflection, allowing multiple planes of movement and reduced friction, along with a control cam system for operator control, and an outer sleeve for reduced friction and potential drug coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If elastic elements like Pebax are used for articulation, then the device can achieve bending deflection, but the bending plane consistency deteriorates due to material homogeneity and manufacturing variations
Solution Approach 1:
The articulation mechanism is divided into multiple discrete links (first link, second link, third link, fourth link) instead of using a continuous elastic element. Each link can pivot independently around defined pivoting points, ensuring consistent bending plane behavior. The segmentation allows each component to be manufactured separately with precise geometric constraints, eliminating the variability inherent in molded elastic materials.
2Reliability
If conventional composite material structures are used, then the endoscope can withstand repeated cleaning and high temperatures, but the flexibility and patient comfort deteriorate
Solution Approach 1:
The patent changes the material parameter from rigid composite materials to flexible materials that can still withstand sterilization. The flexible material structure allows the device to maintain flexibility for patient comfort while being compatible with sterilization processes, representing a parameter change in material selection and structural design.
3Ease of operation
If pull-wire mechanisms are used for deflection control, then active deflection at the distal portion can be achieved, but the shaft tends to twist and form S-shapes under tension
Solution Approach 1:
The patent introduces asymmetric geometric features including tapered sections on the first link and wedge-shaped recesses on the second link. These asymmetric features create mechanical constraints that guide the bending motion to occur in a specific plane, preventing twisting and S-shape formation. The asymmetric geometry ensures that forces are distributed to maintain planar bending while allowing active deflection control.
4Productivity
If conventional endoscopes are designed for multiple uses, then cost per use decreases, but the complexity and fragility increase requiring expensive repair
Solution Approach 1:
The patent describes an articulation mechanism that can be manufactured as a disposable component. By simplifying the design to use stacked links with simple pivot connections rather than complex continuous structures, the device can be produced at low cost for single-use applications, eliminating the need for expensive repair and sterilization infrastructure while maintaining clinical effectiveness.
Data Source
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AI summary
An articulating mechanism for use in a medical device, such as an endoscope or a catheter, includes a series of stacked links disposed adjacent to one another and movable with respect to each other. Each link includes a front face tapered to a pair of pivot points and a rear face defining a wedge shaped recess for receiving the pivot points of the adjacent link. Pull-wires provide tension and hold the staked links together while also allowing for controlled bending of the distal portion by movement of one or more of the pull-wires.