Variable-Stiffness Overtube for Distal Digestive Tract Insertability
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Solution Overview
Problem
Existing overtubes become either too stiff or too soft in the longitudinal direction, leading to reduced insertability of the distal end into the digestive tract and complicating movement operations, particularly in the upper digestive tract.
Innovation Solution
An overtube design with distinct regions: a first region that can switch between flexible and stiff states via fluid supply/discharge, and a second region that is softer than the first region, ensuring optimal flexibility and stiffness for improved insertability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the overtube is switched from softened state to stiffened state, then the supportability and stability are improved, but the insertability of distal end into digestive tract deteriorates
Solution Approach 1:
The overtube is divided into multiple sections with different stiffness characteristics. The distal end portion maintains higher flexibility compared to the proximal end, allowing the insertability to be improved without compromising the overall structural support when needed
Solution Approach 2:
Different portions of the overtube have different flexibility characteristics. The distal end is designed to be softer and more flexible to facilitate insertion into the digestive tract, while the proximal end maintains sufficient stiffness for support and control
2Ease of operation
If the overtube is in softened state, then the insertability is improved, but the movement operation becomes complicated and difficult
Solution Approach 1:
The overtube employs a variable stiffness mechanism that allows dynamic adjustment between softened and stiffened states. This enables the tube to be soft during insertion for ease of operation, then stiffen for stable movement control, reducing operational complexity
3Strength
If the entire overtube becomes stiff, then the supportability is improved, but the flexibility for guidance deteriorates
Solution Approach 1:
The overtube is segmented into regions with different stiffness properties, allowing the proximal end to provide support while the distal end maintains flexibility for guidance and navigation through the digestive tract
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
Enhances the insertability of the overtube's distal end into the digestive tract by maintaining flexibility and control over stiffness, facilitating smoother movement and alignment with the endoscope insertion part.
Implementation Method 1
a shape-deformable body that can be deformed following a shape of the tube body is provided between the outer tube and the inner tube
Implementation Method 2
in a case where an inner space between the outer tube and the inner tube is depressurized, the overtube is in a rigid state (stiffened state)
Implementation Method 3
a first region that is located on a distal end side with respect to the supply and discharge port and includes an outer tube having a flexibility, an inner tube having a flexibility
Implementation Method 4
the fluid is supplied to a space between the outer tube and the inner tube via the supply and discharge port
Data Source
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AI summary
Provided is an overtube with improved insertability of a distal end side of the overtube into a digestive tract. An overtube includes a supply and discharge port for supplying and discharging a fluid, a first region that is located on a distal end side with respect to the supply and discharge port and includes an outer tube, an inner tube, and a shape-deformable body, and a second region that is located on the distal end side with respect to the first region and includes the outer tube and the inner tube. The first region is switchable between a first state in which the fluid is supplied to a tube inner space between the outer tube and the inner tube via the supply and discharge port and a second state that is stiffer than the first state and in which the fluid is discharged, and the second region is softer than the second state of the first region.