Clot Retrieval System Using Shape Memory Alloy Distal Body
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current intravascular thrombus and foreign body removal devices are ineffective in removing hard, organized blood clots from the brain and heart, often causing embolization due to their design, which requires proximal vessel occlusion and is difficult to navigate through tortuous vessels.
Innovation Solution
A deployable system using a memory metal-based catheter-delivered device with a distal body that expands to capture clots, featuring a pull wire and memory metal strips that change configuration to encase and retrieve clots without occluding the vessel, allowing for easy navigation through small catheters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current intravascular thrombus removal devices are used, then device structure is simple, but they are ineffective in removing hard organized clots and cause embolization
Solution Approach 1:
The device is divided into multiple segments including a distal body, proximal body, and intermediate section. The distal body contains multiple struts that can independently engage the clot, while the proximal body houses the compression mechanism. This segmentation allows the device to effectively capture and compress hard organized clots without causing embolization.
Solution Approach 2:
The device utilizes shape memory alloy material that changes its mechanical properties in response to temperature changes. When exposed to body temperature, the alloy transitions from a compressed low-profile state to an expanded functional state, enabling effective clot engagement and compression while maintaining vessel patency.
2Ease of operation
If device is made small and flexible to navigate tortuous vessels, then navigation capability is improved, but device strength to dislodge adherent thrombus is reduced
Solution Approach 1:
The device features a dynamic structure with movable struts and compression mechanisms that can adapt to vessel geometry. The struts can extend and retract, and the compression mechanism can adjust force application, allowing the device to navigate tortuous vessels while maintaining sufficient strength to dislodge adherent thrombus when engaged.
Solution Approach 2:
The device incorporates shape memory alloy material that combines flexibility for navigation with high strength for clot engagement. The alloy's unique properties allow it to be delivered in a compressed state through small catheters, then expand to provide strong mechanical engagement with hard organized clots.
3Reliability
If device expands to capture clot, then clot capture capability is improved, but device size increases making retrieval difficult
Solution Approach 1:
The device employs a nested structure where the distal body with expansion struts can be contained within the proximal body during delivery and retrieval. The intermediate section allows the distal body to expand for clot capture, then be recaptured within the proximal body for retrieval through small catheters, enabling both effective clot capture and easy retrieval.
4Reliability
If device requires proximal occlusion to retrieve clot, then clot retrieval is achieved, but vessel ischemia and injury risk increase
Solution Approach 1:
The device extracts the clot from the vessel by engaging it with the distal body struts and compressing it against the proximal body. The compression mechanism pushes the engaged clot back through the delivery catheter, allowing retrieval without requiring proximal vessel occlusion, thereby eliminating the risk of ischemia and vessel injury associated with traditional occlusion-based retrieval methods.
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 effectively removes hard clots from tortuous vessels without occluding the vessel, reducing embolization risk and improving navigation through small catheters, enabling timely and safe removal of obstructions.
Implementation Method 1
a distal body that expands to capture clots, featuring a pull wire and memory metal strips that change configuration
Data Source
AI summary
The invention relates to systems for removing obstructions and other objects within a blood vessel or other interior lumen of an animal. The system may be deployed in the lumen from a catheter and includes a pull wire having a proximal end and a distal end, and a distal body having a proximal hub, a basket, and a distal hub. In some embodiments, the distal body includes a plurality of proximal strips that form a closeable claw that is used to capture the obstruction. In other embodiments, the basket includes an enlarged opening that allows the object to enter the basket. Optionally, the basket includes x-ray markers adjacent to the enlarged openings to allow the operator to locate the openings, as well as twisting strips that connect the basket to the proximal hub. The present invention also relates to methods of making and using such systems.