Double-Walled Embolic Filter Balloon for Carotid Stenting
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Solution Overview
Problem
Current distal embolic protection systems face challenges with flow stagnation intolerance in patients, larger crossing profiles, and inadequate vessel wall apposition, particularly in irregularly shaped vessels, which limits their effectiveness in preventing distal embolization during carotid angioplasty and stenting.
Innovation Solution
An expandable annular body with a double-walled elastic balloon design that maintains a central lumen for blood flow, featuring multiple inflation lumens and a compliant or non-compliant structure for even expansion, which can be tethered to a guide wire and includes a filter or infusion functionality for enhanced apposition and debris capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a distal embolic filter is used to capture debris, then embolic protection is improved, but the crossing profile becomes larger making it difficult to cross highly occluded or delicate lesions
Solution Approach 1:
The device is divided into multiple segments including a distal filter portion and a proximal occlusion balloon portion, each performing specific functions. The filter portion captures debris while the balloon portion provides occlusion, allowing the system to achieve both embolic protection and low crossing profile by separating these functions into distinct modular components that can be delivered sequentially through the lesion.
Solution Approach 2:
The distal filter is nested within the delivery system and deployed first, followed by the proximal occlusion balloon which is then advanced over the filter. This nested deployment strategy allows both components to pass through the lesion with minimal profile, as each component is contained within the delivery system until deployment, achieving both small crossing profile and effective embolic protection.
2Length of moving object
If an occlusive balloon is used to trap debris, then the crossing profile is reduced, but patients become intolerant to flow stagnation during long procedures
Solution Approach 1:
The occlusion is applied locally at the proximal segment of the device rather than throughout the entire vasculature. The distal filter portion maintains local debris capture while the proximal balloon provides targeted occlusion only where needed, reducing the overall volume of stagnant flow and improving patient tolerance while maintaining the low crossing profile advantage of balloon devices.
3Strength
If a traditional nitinol-framed filter is used, then structural strength is improved, but apposition to irregular shaped vessel walls is inadequate allowing debris to pass through gaps
Solution Approach 1:
The device employs an asymmetric design where the distal filter portion has a compliant structure capable of conforming to irregular vessel wall geometries, while the proximal occlusion balloon provides symmetric radial force. This asymmetric configuration allows the filter to adapt to elliptical or irregular vessel cross-sections, improving wall apposition and eliminating gaps without compromising overall structural integrity.
Solution Approach 2:
The distal filter incorporates a flexible compliant structure rather than a rigid nitinol frame, allowing it to conform to irregular vessel wall shapes. This flexible shell design enables the filter to adapt to elliptical or non-circular vessel cross-sections, improving contact with the vessel wall and preventing debris from passing through gaps, while the proximal balloon provides additional radial support.
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 solution rivals the crossing profile of balloon occlusion devices while providing improved vessel wall apposition and embolic protection, suitable for various vessel shapes and sizes, ensuring effective debris capture and potential therapeutic delivery.
Implementation Method 1
an expandable annular body which is expandable by inflation of a series of inflation lumen defined therein, the device having inflated and non-inflated states
Implementation Method 2
double-walled elastic balloon design that maintains a central lumen for blood flow, featuring multiple inflation lumens and a compliant or non-compliant structure for even expansion
Implementation Method 3
An external wall of the annular body contacts and seals against a vessel wall while an internal wall of the annular body defines a lumen
Implementation Method 4
includes a filter or infusion functionality for enhanced apposition and debris capture
Data Source
Figure 1A~1B
Figure 1C~2F
Figure 2A~2B
AI summary
An inflatable device (1) for use within the vasculature of a body and having an expandable annular body (1a) which is expandable by inflation of a series of inflation lumen (2) defined therein, the device having inflated and non-inflated states and inner (3) and outer (4) annular walls, the device being adapted so that inflationary pressure within the lumen moves the device from the non-inflated state toward the inflated state by radially outward expansion of both the outer and inner walls so that the annular body expands to form an annular structure with a central lumen (6) defined by the inner wall. The device may be employed as an embolic filter.