Flexible Tube Winding Density for Endoscope Insertion
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Solution Overview
Problem
Existing flexible tubes for insertion apparatuses, such as endoscopes, face challenges in efficiently navigating complex anatomical passages due to inconsistent bending rigidity and resilience, which can lead to difficulties in reaching deep portions of the body and cause unwanted bending or sticking phenomena.
Innovation Solution
A flexible tube design featuring a helical tube with alternating closely wound and sparsely wound regions, along with a change region that adjusts unbendability and resilience stepwise, allowing for controlled bending and easy navigation through curved passages by matching the bending characteristics to the external forces encountered.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the flexible tube uses a uniform helical structure, then the manufacturing is simple, but the bending rigidity is inconsistent causing sticking phenomena
Solution Approach 1:
The helical tube is divided into multiple regions with different winding densities: a first sparsely wound region, a closely wound region with alternating closely and sparsely wound portions, and a second sparsely wound region. This segmentation creates varying bending rigidities along the longitudinal axis, preventing sticking phenomena while maintaining navigability through complex passages.
Solution Approach 2:
Different portions of the helical tube are assigned different structural qualities. The closely wound region provides higher bending rigidity for pushability, while the sparsely wound regions provide lower bending rigidity for flexibility and navigation. This local differentiation optimizes both insertion performance and passage navigation.
2Strength
If the wire portions are closely wound, then the pushability and support are improved, but the flexibility and ease of navigation are reduced
Solution Approach 1:
The tube is segmented into regions with different winding densities. The closely wound region (with wire portions applied with tight contact force) provides high pushability and support, while the sparsely wound regions provide flexibility for navigation. This segmentation allows the tube to exhibit both high strength and flexibility at different locations.
Solution Approach 2:
The helical tube structure implements local quality by varying the winding density at different positions. The closely wound portions provide high bending rigidity for pushability, while sparsely wound portions provide low bending rigidity for flexibility. This local differentiation resolves the contradiction between strength and ease of operation.
3Ease of operation
If the wire portions are sparsely wound, then the flexibility and navigation are improved, but the pushability and structural support are reduced
Solution Approach 1:
The tube structure is segmented into sparsely wound regions for flexibility and a closely wound region for pushability. The sparsely wound regions allow easy navigation through curved passages, while the closely wound region provides the necessary structural support and pushability to advance the tube through the passage.
Solution Approach 2:
Different local regions of the tube are assigned different winding densities to optimize their functions. Sparsely wound regions provide flexibility for navigation, while the closely wound region provides strength for pushability. This local quality differentiation allows the tube to simultaneously achieve both navigation flexibility and pushability.
4Strength
If the bending rigidity is increased, then the pushability is improved, but the ability to bend and return to original shape is reduced
Solution Approach 1:
The tube is segmented into regions with different bending rigidities. The closely wound region has high bending rigidity for pushability, while the sparsely wound regions have low bending rigidity for flexibility and resilience. This segmentation allows the tube to push effectively while still being able to bend and return to its original shape in the flexible regions.
Solution Approach 2:
The helical tube implements local quality by varying winding density to create regions with different mechanical properties. The closely wound region provides high bending rigidity for pushability, while sparsely wound regions provide low bending rigidity for resilience. This local differentiation allows the tube to simultaneously achieve pushability and the ability to bend and recover.
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
The flexible tube effectively bends and returns to its original shape, facilitating deep insertion and preventing sticking, by ensuring consistent and adaptable bending properties along its length, thus enhancing the insertion process and reducing the risk of mechanical failure.
Implementation Method 1
a flexible tube defining a longitudinal axis by a distal end and a proximal end thereof, includes: a tubular outer sheath defining a length of the flexible tube; and a helical tube including: a first sparsely wound region arranged along the longitudinal axis, including adjacent wire portions of a wire member which are adjacent along the longitudinal axis and which are separate from each other, and cooperating with the outer sheath to form a first flexible portion
Implementation Method 2
a closely wound region located closer to the proximal side than the first sparsely wound region along the longitudinal axis, the closely wound region including a plurality of closely wound portions that include adjacent wire portions of the wire member which are adjacent along the longitudinal axis applied with a tight contact force
Data Source
AI summary
A flexible tube includes a helical tube having a first sparsely wound region, a closely wound region, a change region, and a second sparsely wound region. In a state where the change region is arranged between the closely wound region and the second sparsely wound region, the change region changes an unbendability such that the unbendability of the distal end portion of the third flexible portion is closer to the unbendability of the second flexible portion and the unbendability of the proximal end portion of the third flexible portion is closer to the unbendability of the fourth flexible portion.