Clot Retrieval Device with Segmented Memory Metal Basket
Solution Overview
Problem
Current devices for removing blood clots from intracranial vessels are ineffective in addressing hard, organized thrombi, often failing to dislodge clots from vessel walls and causing embolization due to their design limitations, such as open-ended structures and the need for proximal vessel occlusion, which can lead to further ischemia and vessel injury.
Innovation Solution
A deployable system comprising a pull wire with a distal body featuring memory metal strips that expand to capture clots, allowing for safe dislodgment and retrieval without occluding the vessel, using a claw mechanism to securely entrap the clot and prevent embolization, and a catheter system that can be easily maneuvered to navigate tortuous vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a device is made small and flexible to navigate tortuous vessels, then it can navigate through tortuous vessels within guide catheter and microcatheter, but it becomes weak and cannot dislodge strongly adherent thrombus from vessel wall
Solution Approach 1:
The device is divided into multiple segments including a distal basket portion and a proximal basket portion, each capable of independent expansion and contraction. This segmentation allows the device to navigate tortuous vessels in a compressed state while providing sufficient surface area and structural integrity when expanded to dislodge and capture thrombus effectively
Solution Approach 2:
The device employs dynamic expansion and contraction capability through memory metal strips that can transition between compressed and expanded states. The basket portions can be expanded to engage thrombus with sufficient force for dislodgment, then contracted for retrieval through the catheter system, providing both navigation flexibility and thrombus removal strength
2Ease of operation
If an open-ended device structure is used, then the device is simple to deploy, but the thrombus embolizes into another or the same vessel due to the open ended nature
Solution Approach 1:
The retrieval device is segmented into a distal basket portion and a proximal basket portion that can work together to form a closed or partially closed configuration. The proximal basket portion can be positioned to block the open end of the distal basket, creating a enclosed space that securely traps thrombus and prevents embolization while maintaining relatively simple deployment procedures
Solution Approach 2:
The device dynamically transitions between open and closed configurations. The basket strips can be expanded to an open state for easy thrombus engagement, then contracted or repositioned to a closed state for secure entrapment and retrieval, providing both operational simplicity and thrombus security
3Reliability
If proximal vessel occlusion is used to retrieve thrombus, then the thrombus can be removed, but it carries risk of further ischemia and risk of vessel injury
Solution Approach 1:
The device extracts the thrombus from the vessel lumen by navigating to the thrombus location, engaging it with the expanded basket structure, and retrieving it through the catheter system without requiring occlusion of the proximal vessel. This extraction approach removes the harmful thrombus while avoiding the creation of additional harmful occlusion effects
Solution Approach 2:
The retrieval device acts as an intermediary tool that facilitates thrombus removal without requiring direct vessel occlusion. The device can be advanced through the vessel system, positioned at the thrombus, and used to capture and extract the thrombus, serving as a mediator that achieves thrombus removal while minimizing harm to the vessel and surrounding tissue
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 intracranial vessels by securely capturing and retrieving them without causing further ischemia or vessel injury, ensuring complete removal and preventing embolization, thus addressing the limitations of existing technologies.
Implementation Method 1
a distal body... comprising an interior, an exterior, a proximal end, a distal end, a plurality of proximal memory metal strips located at the proximal end
Data Source
AI summary
A platform of devices for removing obstructions and other objects within a blood vessel or other interior lumen of an animal is provided. The system may be deployed in the lumen from a catheter(s) and the system includes a proximal hub, and a distal basket comprised of a plurality of cells. A number of different baskets designs are disclosed. Methods of manufacturing such baskets out of a single tube of a memory metal without the need for any welding, and methods of use are also disclosed.