Dual-Basket Clot Retrieval Structure to Minimize Embolization

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Solution Overview

Problem

Current medical devices for removing blood clots and obstructions from intracranial vessels are ineffective in addressing hard, organized thrombi and often cause embolization due to their design flaws, 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 made of memory metal strips that can expand to capture and remove obstructions, featuring a claw mechanism and a basket design to encase the clot, allowing for safe retrieval without proximal occlusion and minimizing embolization risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If currently available thrombus removal devices (MERCI, PENUMBRA, SOLITAIRE, TREVO) are used, then the device can be delivered through tortuous vessels and deployed at the occlusion site, but the device fails to effectively remove hard organized thrombus and causes embolization due to open-ended structure

Engineering Contradiction:

Improvethrombus removal effectivenessVSAvoidembolization

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The distal body is divided into multiple memory metal strips that can be independently configured to form a closed structure. These strips are segmented along the longitudinal axis, allowing each strip to flex and conform to the thrombus while maintaining overall structural integrity to prevent embolization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device transitions from a compressed delivery state to an expanded treatment state through the memory metal's shape recovery properties. The distal body dynamically changes configuration to engage and secure the thrombus, then reverses to retrieve the thrombus without embolization risk.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If the device is made small and flexible to navigate through tortuous vessels, then the device can be delivered through microcatheters, but the device lacks the strength to dislodge strongly adherent thrombus from the vessel wall

Engineering Contradiction:

Improvedeliverability through tortuous vesselsVSAvoidthrombus dislodgement force

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The memory metal strips undergo phase transformation or shape recovery when exposed to body temperature or mechanical activation, changing from a flexible delivery state to a rigid treatment state. This parameter change enables the device to gain sufficient strength for thrombus dislodgement after successful delivery through tortuous vessels.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the device requires proximal occlusion to retrieve the thrombus, then the thrombus can be securely removed, but the risk of further ischemia and vessel injury increases

Engineering Contradiction:

Improvethrombus retrieval securityVSAvoidischemia and vessel injury

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Instead of requiring proximal occlusion to secure the thrombus during retrieval, the device inverts the approach by using a closed distal structure to capture and contain the thrombus. The thrombus is secured at the distal end and retrieved through the microcatheter without needing to occlude the proximal vessel, thereby eliminating the harmful effects of prolonged occlusion.

Inventive Principle:

Principle #13The other way round (Inversion)

4Object-generated harmful factors

If the device uses a closed structure to prevent embolization, then embolization risk is reduced, but the device complexity increases

Engineering Contradiction:

Improveembolization preventionVSAvoiddevice structure

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The closed structure is formed using flexible memory metal strips that can be collapsed into a compact configuration for delivery and expanded to form a closed cage for thrombus capture. This flexible shell approach achieves embolization prevention without excessive structural complexity, as the same material and basic geometry serve both delivery and treatment functions.

Inventive Principle:

Principle #30Flexible shells and thin films

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 captures and removes hard clots without causing further embolization, reducing the risk of vessel injury and allowing for multi-use within the same patient treatment, while being easy to manufacture and use.

Implementation Method 1

a distal body... comprising a plurality of proximal memory metal strips located at the proximal end

Methodology Applied

Scientific EffectShape memory effect: Shape Memory Alloy

Data Source

PatentUS11413054B2Catheter-delivered endovascular devices

Publication Date: 2022.08.16 VESALIO INC

AI summary

Catheter-delivered endovascular medical devices are described. The devices may include a pull wire attached to a deployable dual basket system. The deployable dual basket system may include a proximal basket and a distal basket that are connected by basket connector tether memory metal strips that rotate/twist relative to the longitudinal axes of the basket and form flex points of the system. The proximal basket and the distal basket may be comprised of a plurality of cells and the proximal basket may taper at its proximal end and the distal basket may be tapered at its distal end. Methods of using and making the devices are also described.