Medical Device Incising Member Sliding Core Wire
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Solution Overview
Problem
Existing medical devices with incising members for treating calcified stenosis or stricture face issues where the incising member becomes detached during radial expansion or contraction of the expandable-and-contractible member, and interferes with its movement, leading to potential impairment of blood vessel or digestive organ walls.
Innovation Solution
A medical device design featuring an incising member with a hollow portion open towards the proximal end, a core wire inserted from the proximal end that can slide longitudinally within this hollow portion, and a distal tip and ring for secure attachment to both ends of the expandable-and-contractible member, preventing detachment and optimizing positioning during expansion and contraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the incising member is directly fixed to the outer circumference of the wire that constitute the expandable-and-contractible member, then the incising member can incise the stenosis or stricture in the longitudinal direction upon radial expansion, but the incising member cannot move in the longitudinal direction as the expandable-and-contractible member expands or contracts, causing interference with the expanding or contracting movement
Solution Approach 1:
The incising member is designed to be movable along the core wire in the longitudinal direction, transitioning from a fixed state during delivery to a mobile state during expansion. This dynamic capability allows the incising member to move freely during radial expansion and contraction of the expandable-and-contractible member, eliminating interference while maintaining incising function when needed.
Solution Approach 2:
The incising member is separated from direct fixation to the expandable-and-contractible member wires. Instead, it is positioned on the outer circumference and allowed to move independently along the core wire, creating a segmented structure where the incising member can move relative to the expandable-and-contractible member during expansion and contraction.
2Stability of the object's composition
If the incising member is directly fixed to the expandable-and-contractible member, then the incising member remains in position, but the incising member comes off the expandable-and-contractible member when the expandable-and-contractible member is forcefully made expand or when the stenosis or stricture is caught between them
Solution Approach 1:
The core wire serves as an intermediary element between the incising member and the expandable-and-contractible member. The incising member is positioned on the outer circumference of the expandable-and-contractible member and can move along the core wire, allowing it to remain stable during normal operation while accommodating forceful expansion or stenosis entrapment without detaching.
Solution Approach 2:
The incising member is designed with dynamic positioning capability along the core wire, allowing it to adjust its position during forceful expansion or when stenosis is caught. This dynamic design prevents detachment by enabling the incising member to move with the expandable-and-contractible member rather than being rigidly fixed.
3Ease of operation
If the incising member is not fixed to the expandable-and-contractible member, then the incising member can move freely during expansion and contraction, but the incising member may detach during manipulation when stenosis is caught between components
Solution Approach 1:
The core wire acts as an intermediary that guides and constrains the incising member's movement. The incising member can move freely along the core wire during expansion and contraction, but the core wire prevents complete detachment by serving as a track that limits the incising member's movement to the longitudinal direction only.
Data Source
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AI summary
[PROBLEMS TO BE SOLVED] An object of the present invention is to provide a medical device in which an incising member is not likely to come off upon radial expansion or radial contraction of an expandable-and-contractible member and the incising member is not likely to interfere with the expanding or contracting movement of the expandable-and-contractible member. [SOLUTION] A medical device 1 has a configuration where a distal end 11 of an expandable-and-contractible member 10 and a distal end 21 of an incising member 20 are fixed to a distal tip 40, a proximal end 12 of the expandable-and-contractible member 10 and a proximal end 33 of a core wire 30 are fixed to a ring 50, the core wire 30 is inserted in a hollow portion 22 of the incising member 20 from a proximal end direction, and the core wire 30 can slide in the longitudinal direction within the hollow portion 22 as the expandable-and-contractible member 10 expands or contracts. Owing to the presence of the core wire 30 inserted in the hollow portion 22, the incising member 20 does not come off the expandable-and-contractible member 10 as the expandable-and-contractible member 10 expands or contracts and can slide to an optimum position. As a result, the possibility of the incising member 20 interfering with the radial expansion or the radial contraction of the expandable-and-contractible member 10 can be reduced. The core wire 30 can be pulled out of the hollow portion 22 of the incising member 20 (in other words, the core wire 30 and the incising member 20 can become separated from each other), so that the load (external force) applied on the incising member 20 by the stenosis or stricture that is caught can be reduced, consequently reducing the possibility of the incising member 20 coming off.