Selective Deployment Mechanisms for Repositionable Stent-Grafts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing delivery systems for stents and stent-grafts face challenges in precisely positioning and deploying these devices in a minimally invasive manner, particularly in navigating tortuous vasculature while ensuring accurate deployment and staged expansion.
Innovation Solution
A medical device deployment apparatus featuring constraining fibers arranged in a warp knit pattern about the device circumference, allowing for staged deployment through sequential release of interlocking strands, enabling controlled expansion from a constrained to fully deployed configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a stent or stent-graft is radially compressed to be mounted on a delivery catheter, then the device can be delivered through tortuous vasculature and through introducer sheaths, but the device cannot be deployed at the target location
Solution Approach 1:
The constraint system is divided into multiple independent constraining fibers that can be selectively released. Each fiber can be independently manipulated to control different stages of deployment, allowing the device to transition from a compressed delivery state to an expanded deployed state while maintaining reliability throughout the process
Solution Approach 2:
The constraint system transitions from a static compressed state to a dynamic deployable state through controlled release of constraining fibers. The system allows for intermediate configurations where the device can be partially expanded and re-constrained, enabling precise control over the deployment process at the target location
2Reliability
If a stent or stent-graft is deployed to expand at the target location, then the device can provide radial support, but the device cannot be repositioned or adjusted
Solution Approach 1:
The constraint system enables dynamic control over device expansion and repositioning. By selectively releasing and re-constraining individual fibers, the operator can adjust the device position and expansion degree before final deployment, providing both repositioning capability and reliable radial support when fully deployed
Solution Approach 2:
The device is preliminarily positioned and constrained in a compressed state during delivery, then selectively expanded to intermediate configurations for verification and adjustment before final deployment. This preliminary action allows verification of correct positioning while maintaining the ability to reposition if needed
3Reliability
If a stent or stent-graft is fully deployed, then the device provides maximum radial support, but the device cannot be visualized or verified at the target location
Solution Approach 1:
The constraint system allows the device to be deployed to intermediate configurations that are visible and verifiable at the target location. The operator can control the expansion degree to achieve optimal visualization for verification while maintaining the capability to achieve full deployment for maximum radial support when verification is complete
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
Facilitates precise, minimally invasive deployment and visualization of medical devices, allowing for staged expansion and adjustment during delivery, enhancing navigation through complex vasculature.
Implementation Method 1
Some stents are designed to elastically recover by being manufactured at their functional diameter out of a material that has elastic recovery properties, and then radially compressed to be mounted on a delivery catheter
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Various aspects of the present disclosure are directed toward medical device deployment apparatuses, systems and methods. The apparatuses, systems and methods may include at least one constraining fiber arranged about a circumference of the medical device and a warp knit configured to separate to deploy the medical device to at least one intermediate constrained configuration and to a fully deployed configuration.