Stent Delivery System with Spirally Twisted Balloon
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Solution Overview
Problem
Current stent delivery systems face challenges in achieving a balance between flexibility and radial strength, particularly in navigating tortuous vascular paths and maintaining structural integrity under cyclic loading and radial compressive forces.
Innovation Solution
A stent delivery system featuring a balloon catheter with a spirally twisted balloon configuration and a stent made from a single continuous wire formed into a sinusoidal waveform, which undergoes dynamic deployment upon inflation, resulting in crowns with obtuse and acute deployment angles for enhanced flexibility and radial strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the stent is made with a traditional uniform structure, then the manufacturing process is simple, but the stent cannot simultaneously achieve sufficient flexibility for navigation and adequate radial strength for support
Solution Approach 1:
The stent structure transitions from uniform to non-uniform by creating alternating dense and sparse crown regions. The dense crowns provide high radial strength for vessel support, while the sparse crowns provide flexibility for navigation through tortuous vasculature. This local variation in structural density allows the stent to simultaneously achieve both flexibility and radial strength that cannot be obtained with a uniform structure.
Solution Approach 2:
The stent is segmented into distinct regions with different crown densities along its length. By dividing the stent into segments with varying structural characteristics (dense vs. sparse crowns), each segment can perform its specialized function - some segments prioritize radial support while others prioritize flexibility - thereby resolving the contradiction between these two opposing requirements.
2Adaptability or versatility
If the stent is crimped onto a conventional balloon for delivery, then the delivery system is simple, but the stent cannot achieve dynamic deployment with varying crown angles
Solution Approach 1:
The delivery system transitions from static to dynamic by incorporating a spirally twisted balloon configuration. When the balloon is inflated, the spiral twist dynamically transforms into radial expansion forces that selectively deploy crowns at different angles. This dynamic mechanism enables the stent to achieve varying crown deployment angles (acute in dense regions, obtuse in sparse regions) without requiring a complex multi-component delivery system.
Solution Approach 2:
The balloon's physical state changes from a compressed spiral configuration to an expanded cylindrical configuration during deployment. This parameter change in the balloon's geometry transforms the delivery mechanism, allowing it to dynamically control the deployment angles of different crown regions. The spiral-to-cylindrical transformation creates differential expansion forces that achieve the desired dynamic deployment pattern.
3Strength
If the stent has high radial strength to resist compressive forces, then the stent can maintain vessel patency, but the stent becomes rigid and difficult to maneuver through tortuous vascular paths
Solution Approach 1:
The stent structure uses local variation in crown density to resolve the strength-flexibility trade-off. Dense crown regions with closely spaced struts provide high radial strength to resist compressive forces and maintain vessel patency, while sparse crown regions with widely spaced struts provide flexibility and conformability for navigating tortuous vascular paths. This spatially differentiated structure allows the stent to exhibit both high strength and good maneuverability simultaneously.
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 system achieves a desirable balance of flexibility and radial strength, allowing for effective deployment and maintenance of the stent within the body lumen, with dynamically deployed crowns providing increased radial strength and flexibility, reducing recoil and maintaining vessel patency.
Implementation Method 1
a stent made from a single continuous wire formed into a sinusoidal waveform that is wrapped into a helical pattern
Implementation Method 2
Upon inflation of the spirally twisted balloon of the stent delivery system, the stent undergoes dynamic deployment
Data Source
AI summary
A stent delivery system for dynamic deployment of a stent loaded thereon and a method of manufacturing the system. The stent delivery system includes a balloon catheter with a balloon in a spirally twisted delivery configuration on which a stent is crimped or otherwise loaded. The stent is made from a single, continuous strand of wire formed into a sinusoidal waveform that is wrapped into a helical pattern and joined at selected crowns. Upon inflation of the spirally twisted balloon of the stent delivery system, the stent undergoes dynamic deployment such that the stent in a deployed or expanded configuration has crowns with obtuse deployment angles and crowns with acute deployment angles.