Stent Deployment System with Radial Sheath Cutting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stent deployment methods face challenges with high friction between stents and deployment systems, leading to increased deployment forces and difficulties in stent placement, often requiring larger delivery devices that contradict market requirements.
Innovation Solution
The development of alternative delivery systems featuring a cutting element, such as a blade or saw tooth blade, integrated into the outer tubular member to radially cut the sheath upon retraction, reducing surface area interaction and minimizing the force required for stent deployment by releasing the stent from its radially collapsed configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional stent deployment methods are used with continuous contact between delivery system and stent, then stent can be delivered to target location, but high friction increases deployment force requirements and delivery device size
Solution Approach 1:
The delivery system is segmented into an outer tubular member and an inner tubular member that can move relative to each other. The cutting element is integrated into the outer tubular member to divide the sheath, allowing the stent to be released in segments rather than requiring complete removal of the entire delivery system, thereby reducing deployment force while maintaining manageable device size
Solution Approach 2:
The cutting element is extracted as a separate functional component integrated into the outer tubular member. This element radially cuts the sheath to release the stent from the inner tubular member, separating the deployment function from the delivery function and reducing the frictional contact area during expansion
Solution Approach 3:
The cutting action transitions from axial to radial direction. The cutting element extends radially inward from the inner surface of the outer tubular member and cuts the sheath in the radial dimension, allowing the stent to expand outward while minimizing contact friction with the delivery system
2Reliability
If larger delivery devices are used to overcome high friction, then stent deployment becomes feasible, but it contradicts market requirements for smaller device sizes
Solution Approach 1:
The cutting element is positioned and ready to cut the sheath before stent deployment begins. This preliminary action of dividing the sheath reduces the frictional contact area in advance, allowing reliable stent deployment without requiring oversized delivery devices
Solution Approach 2:
The system changes the friction parameter by reducing the contact surface area between the stent and delivery system through radial cutting of the sheath. This parameter change enables reliable deployment with smaller delivery devices by lowering the friction force that must be overcome
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 approach decreases the deployment force needed, allowing for more efficient and effective stent placement with reduced friction, thereby accommodating smaller delivery device sizes while ensuring successful stent expansion within the body lumen.
Implementation Method 1
high friction between stents and deployment systems, leading to increased deployment forces
Implementation Method 2
an expandable stent disposed about the outer surface of the inner tubular member adjacent the distal end region of the inner tubular member
Data Source
AI summary
A delivery system for delivering a stent to a body lumen. The delivery system includes a tubular member having an expandable stent disposed about the outer surface of the inner tubular member. The stent is maintained in a radially compressed configuration with a removable sheath. The sheath can be released using a variety of techniques.