Stent with External Fluid Path and Localized Coating
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Solution Overview
Problem
Conventional stents cause tissue protrusion and friction issues when inserted into constricted ducts, leading to potential injury and inadequate fluid flow, especially when curved or divergent ducts are involved, and existing solutions like full coverage with silicon or films are costly, inflexible, and require additional biological testing.
Innovation Solution
A stent design featuring a hollow circumferential part with external paths formed by recessions or projections along its length, allowing fluid flow outside the stent, combined with a film and coating layer to prevent tissue protrusion and enhance flexibility, eliminating the need for sutures and reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire stent is coated with silicon to close holes, then tissue protrusion is prevented and stable fixation is achieved, but the stent loses flexibility and causes friction on diseased parts
Solution Approach 1:
The stent applies different treatments to different regions: the circumferential part is coated with silicon to prevent tissue protrusion, while the longitudinal part remains uncoated to maintain flexibility and reduce friction. This localized differentiation resolves the contradiction between reliability and adaptability.
2Reliability
If the stent is entirely covered with silicon or film, then body fluid flows smoothly inside the stent, but body fluid from divergent ducts cannot flow smoothly
Solution Approach 1:
The stent surface is segmented into two functional zones: a circumferential coated part for internal fluid flow and a longitudinal uncoated part that serves as an external path for fluid from divergent ducts. This segmentation allows both flow requirements to be satisfied simultaneously.
Solution Approach 2:
The invention adds an external flow path dimension by utilizing the longitudinal surface of the stent. Instead of relying solely on internal holes for fluid passage, the uncoated longitudinal surface provides an additional external pathway for fluid from divergent ducts to reach the duct lumen.
3Reliability
If a film is used to cover the stent, then tissue protrusion is prevented, but additional biological testing and suture fixation are required, increasing cost and manufacturing time
Solution Approach 1:
The invention extracts the coating application to only the circumferential part of the stent, eliminating the need for additional films and sutures. The silicon coating is applied directly during stent manufacturing without requiring separate biological testing or assembly steps, thereby reducing device complexity.
4Ease of operation
If holes are formed in the stent to reduce friction, then tissue protrusion occurs when pressure increases, but without holes the stent cannot be easily inserted
Solution Approach 1:
The stent structure is differentiated into a circumferential part with holes for easy insertion and a longitudinal part without holes to prevent tissue protrusion. The circumferential holes facilitate initial insertion while the covered longitudinal surface prevents harmful tissue interaction during expansion.
Data Source
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AI summary
A stent according to the present invention includes: a stent main body that has a plurality of holes formed in the surface thereof and a circumferential part of which the inside is hollow; and a cover that covers one side of the outer circumferential surface of the stent main body, in which the stent main body has an exterior path that provides a channel through which the body fluid secreted from a diverging duct can flow along the longitudinal direction of the stent main body to the outside of the cover.