Expandable Sheath for Minimizing Vessel Trauma

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Solution Overview

Problem

Conventional sheaths used in medical devices for procedures like stent implantation and heart valve replacement cause trauma to body passageways due to their large profile, leading to longitudinal and radial tearing of blood vessels during insertion and removal.

Innovation Solution

An expandable sheath that temporarily increases in diameter to accommodate medical devices and then returns to its original size, minimizing trauma by using shape memory materials and polymer layers to facilitate expansion and contraction, thereby reducing the need for multiple dilators and minimizing vessel damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional sheath with large profile is used to deliver medical devices, then the medical device can be delivered through the body passageway, but trauma to the body passageway increases due to longitudinal and radial tearing of blood vessels

Engineering Contradiction:

Improvemedical device delivery capabilityVSAvoidtrauma to body passageway

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The sheath transitions from a compressed low-profile state during insertion to an expanded high-profile state at the treatment site, and then back to compressed state during removal. This dynamic size change allows the sheath to provide protection and support when needed while minimizing trauma during insertion and removal by reducing its profile at those times.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The medical device is nested within the sheath during delivery, with the sheath providing a protective pathway through the body passageway. The sheath can be compressed to a smaller diameter to facilitate insertion, then expanded to accommodate and protect the medical device at the treatment site, and finally compressed again for safe removal.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of operation

If multiple dilators are used to access the body passageway, then access can be achieved, but procedure time increases and trauma risk increases

Engineering Contradiction:

Improvebody passageway access capabilityVSAvoidprocedure time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The sheath is designed with a segmented or collapsible structure that allows it to be compressed to a small diameter for insertion, then expanded to a large diameter for device delivery. This single expandable structure replaces the need for multiple sequential dilators, reducing both procedure time and cumulative trauma to the body passageway.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sheath's diameter parameter is dynamically changed from a small compressed state during insertion to a large expanded state during device delivery. This parameter change allows a single device to perform the function of multiple dilators with different sizes, reducing procedure time and the number of insertion/removal cycles that cause trauma.

Inventive Principle:

Principle #35Parameter changes

3Strength

If the sheath maintains a large diameter throughout the procedure, then medical device support is improved, but trauma to the body passageway increases during insertion and removal

Engineering Contradiction:

Improvemedical device supportVSAvoidvessel tearing during insertion

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The sheath dynamically adjusts its diameter based on the procedural stage: compressed to small diameter during insertion to minimize trauma, expanded to large diameter at the treatment site to provide strong support for the medical device, and compressed again during removal. This dynamic adaptation resolves the contradiction between needing strength and avoiding trauma.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The sheath is pre-compressed to a small diameter before insertion to facilitate easy passage through the body passageway. Once in position, it is then expanded to provide the necessary support for device delivery. This preliminary compression action prevents trauma during insertion while maintaining the capability to provide strength when needed.

Inventive Principle:

Principle #10Preliminary action

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 expandable sheath reduces trauma to body passageways, shortens procedure time, and minimizes the risk of vessel tears and plaque dislodgement, allowing for safer and more efficient delivery of medical devices.

Implementation Method 1

using shape memory materials and polymer layers to facilitate expansion and contraction

Methodology Applied

Scientific EffectShape memory: Shape Memory Alloy

Implementation Method 2

using shape memory materials and polymer layers to facilitate expansion and contraction

Methodology Applied

Scientific EffectElastic recovery: Elastic Recovery

Data Source

PatentUS20240293229A1Expandable sheath for an implant

Publication Date: 2024.09.05 MIRUS LLC

AI summary

The present disclosure relates to a sheath that is usable with a medical device, particularly to a sheath that is usable with a medical device and which sheath is expandable in the regions where the medical device is positioned in the sheath, and more particularly to a sheath that is usable with a medical device and which sheath is expandable in the regions where the medical device is positioned in the sheath and which sheath reforms to its same or similar size and shape after the medical device has passed through a portion or all of the sheath. The sheath facilitates in the insertion of a medical device into the body passageway of a patient.