Sheathing Tool for Intravascular Device Loading and Self-Expansion

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Solution Overview

Problem

Current medical procedures for removing occlusions from body lumens and vessels face challenges such as dislodgment of clot fragments, trauma to vessel walls, and incomplete clot removal due to the use of oversized stents and manual manipulation, which can lead to further vascular damage and complications like hemorrhagic stroke.

Innovation Solution

A system with a sheathing tool that includes a first and second channel to facilitate the constrained loading and unloading of an expandable treatment device, allowing for self-expansion of the device while maintaining its diameter, thereby reducing trauma and improving clot retrieval efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an oversized stent is used to remove clot, then the stent can push the clot to the side of the vessel, but the stent causes trauma to the vessel walls and can strip the cellular lining

Engineering Contradiction:
Improveclot removal effectivenessVSAvoidvessel wall trauma
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The treatment device is nested within a sheath that is delivered through a catheter. The sheath constrains the treatment device during delivery and allows controlled deployment at the target site, preventing the device from contacting and traumatizing the vessel walls during navigation through the vasculature.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The sheath acts as an intermediary between the treatment device and the vessel wall. It provides a protective interface that allows the treatment device to be delivered and deployed without direct contact with the vulnerable vessel lining, thereby preventing mechanical trauma.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a stent is dragged through the vasculature to retrieve clot, then the procedure is easy to perform, but the clot may dislodge or fragment and lodge in smaller vessels

Engineering Contradiction:
Improveprocedure simplicityVSAvoidclot retention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The sheath is prepared and positioned in advance before the treatment device is deployed. The sheath creates a controlled environment that secures the treatment device and allows for systematic clot retrieval, reducing the risk of premature dislodgment or fragmentation during the procedure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The retrieval process is segmented into controlled steps: the sheath is advanced to the target site, the treatment device is deployed within the sheath, clot retrieval is performed, and then the device is withdrawn. This segmentation allows for better control and reduces the risk of clot fragmentation compared to dragging the device through the vasculature.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the treatment device is completely removed from the catheter between passes, then the device can be fully inspected, but the procedure time increases and efficiency decreases

Engineering Contradiction:
Improvedevice inspection capabilityVSAvoidprocedure duration
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The treatment device remains nested within the sheath-catheter assembly between passes, allowing for quick repositioning and repeated use without complete removal. This nesting arrangement enables efficient multi-pass procedures while maintaining the ability to inspect and adjust the device as needed.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The sheath-catheter assembly allows the treatment device to remain in place and ready for repeated passes without complete removal. This continuity eliminates the time loss associated with full device retrieval and re-loading, enabling efficient multi-pass clot retrieval procedures.

Inventive Principle:
Principle #20Continuity of useful action

4Length of moving object

If the treatment device maintains a constrained diameter during delivery, then it can navigate tortuous anatomy, but the device cannot expand to effectively retrieve clot until deployment

Engineering Contradiction:
Improvedevice deliverabilityVSAvoidclot retrieval effectiveness
Core Design Contradiction:
Length of moving objectVSProductivity

Solution Approach 1:

The treatment device transitions from a constrained, low-profile state during delivery to an expanded, functional state at the deployment site. This dynamic transformation allows the device to navigate tortuous anatomy in its constrained form and then expand within the sheath to effectively retrieve clot without traumatizing the vessel walls.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The treatment device is nested within the sheath in its constrained state during delivery through tortuous anatomy. Once positioned at the target site, the device is allowed to expand within the protective environment of the sheath, achieving its full functional diameter for effective clot retrieval without direct contact with the vessel wall.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 enables safer and more effective removal of occlusions by minimizing dislodgment and trauma, allowing for multiple passes without vessel damage, and facilitating the re-sheathing of treatment devices for repeated use, thus enhancing the efficiency and safety of procedures like thrombectomy.

Implementation Method 1

the second opening is spaced apart from the first opening by a gap, the length of the gap being great enough to allow a first portion of the treatment device to self-expand over the sidewall

Methodology Applied
Scientific EffectSelf-expansion: Elastic Recovery

Data Source

PatentEP3638134B1Tools for sheathing treatment devices and associated systems
Publication Date: 2023.08.16 COVIDIEN LP
  • EP3638134B1 patent drawingFigure 1
  • EP3638134B1 patent drawingFigure 2
  • EP3638134B1 patent drawingFigure 3A~3B

AI summary

Devices for loading intravascular treatment devices into a sheath and associated systems and methods are disclosed herein. A sheathing tool may include, for example, a first channel extending to a first opening, the first channel configured to receive a treatment device in a constrained state therethrough. The treatment device may include an elongated member and a first element and a second element at a distal region of the elongated member. The second channel extending to a second opening, the second opening surrounded by a sidewall and configured to receive the treatment device in the constrained state therethrough, wherein the second opening is spaced apart from the first opening by a gap, and wherein a length of the gap is great enough to allow the first element to self-expand over the sidewall while the second element generally maintains its diameter in the constrained state while crossing the gap.