Stent Delivery Balloon Folding Direction Inversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Helically shaped stent struts are prone to twisting during expansion, which can lead to re-coiling when deployed in a lumen, as they do not maintain their shape effectively due to uneven expansion forces.
Innovation Solution
The stent delivery system employs a balloon folding direction opposite to the helical extending direction of the stent strut, ensuring that the expansion force aligns with the helical direction, preventing twist and re-coiling by maintaining even expansion of the helical portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a helical strut is used to improve flexibility, then the stent can follow the lumen shape better, but the strut becomes easily twisted during expansion
Solution Approach 1:
The patent applies inversion by making the balloon folding direction opposite to the helical extending direction of the strut. The balloon is folded in a first circumferential direction while the strut helix extends in a second circumferential direction opposite to the first. This opposite direction configuration ensures that when the balloon inflates, the expansion force acts in the same direction as the helical extending direction, preventing twist and maintaining strut stability.
2Ease of operation
If the strut is twisted during expansion, then the stent can be delivered, but the stent may re-coil when indwelled in the lumen
Solution Approach 1:
The patent resolves the re-coiling issue by inverting the balloon folding direction relative to the strut helical direction. This configuration ensures that the expansion force from balloon inflation acts in the same direction as the helical extending direction of the strut, preventing twist during expansion and thereby preventing re-coiling after the stent is delivered and indwelled in the lumen.
3Productivity
If the balloon is inflated to expand the stent, then the stent is deployed, but uneven expansion forces cause the helical strut to twist
Solution Approach 1:
The patent ensures even expansion by inverting the balloon folding direction opposite to the strut helical direction. When the balloon inflates, the expansion force is applied in the same direction as the helical extending direction, causing uniform expansion of the helical strut without twist. This configuration transforms the expansion process into a controlled, even expansion that maintains strut integrity.
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
This configuration effectively inhibits twisting and re-coiling of the stent, ensuring it remains expanded and functional within the lumen, thereby maintaining the open state of the lumen effectively.
Implementation Method 1
a balloon catheter comprised of an elongated shaft and an inflatable/deflatable balloon provided at a distal end side of the shaft
Implementation Method 2
the helical portion receives a force in the helical extending direction as the limb portion moves, the helix evenly expands, so that it is possible to prevent a twist of the stent
Data Source
AI summary
To provide a stent delivery system configured to prevent twisting of a strut during expansion of a stent. A balloon has a plurality of limb portions folded at a plurality of folding pleats in a deflated state. The limb portions are folded in a first circumferential direction to surround the shaft as seen from a proximal end side of an axial direction of the shaft. The strut of the stent has helical portions formed in a helical shape extending along a second circumferential direction opposite to the first circumferential direction as seen from the proximal end side of the axial direction with being centered on an axis extending along the axial direction of the shaft.