Expandable Introducer Sheath With Foldable Tip for Low-Trauma Delivery

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Solution Overview

Problem

Conventional introducer sheaths for delivering prosthetic devices like heart valves pose risks of vessel damage and plaque dislodgment due to their large profile and complex mechanisms, hindering safe and efficient delivery and retrieval.

Innovation Solution

An expandable introducer sheath with a distal tip assembly featuring a flap configuration and a proximal seal, allowing for enhanced expansion and minimization of wall thickness, along with a collapsible design to reduce profile and minimize vessel damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional introducer sheath with a tubular loader is used, then the delivery path is unobstructed, but the available working length of the delivery apparatus is decreased

Engineering Contradiction:

Improvedelivery path unobstructedVSAvoidavailable working length

Core Design Contradiction:

Ease of operationVSLength of moving object

Solution Approach 1:

The inner member is nested within the outer member, with the inner member providing structural support and the outer member providing sealing and protection. This nested configuration allows the loader to be integrated within the sheath structure rather than extending externally, preserving working length while maintaining an unobstructed delivery path through the coordinated expansion of both members.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If multiple dilators or sheaths are used to dilate the vessel progressively, then the vessel is adequately prepared, but the procedure time increases and vessel damage risk increases

Engineering Contradiction:

Improvevessel preparationVSAvoidprocedure time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The sheath employs an expandable structure that can progressively increase its diameter from a compressed delivery state to an expanded deployed state. This allows the vessel to be dilated in a controlled manner as the sheath expands, preparing the vessel adequately while reducing procedure time by eliminating the need for multiple separate dilators.

Inventive Principle:

Principle #35Parameter changes

3Shape

If the sheath wall thickness is minimized, then the profile is reduced, but the structural strength and sealing capability are compromised

Engineering Contradiction:

ImproveprofileVSAvoidstructural strength

Core Design Contradiction:

ShapeVSStrength

Solution Approach 1:

The sheath is constructed with a composite structure featuring an inner member and an outer member, where each layer provides specific functional properties. The inner member provides structural support and radial strength, while the outer member provides sealing capability and protection. This composite construction allows minimal wall thickness for reduced profile while maintaining adequate structural strength and sealing through the coordinated properties of both layers.

Inventive Principle:

Principle #40Composite materials

4Area of moving object

If a flap configuration is used in the distal tip assembly, then expansion diameter is enhanced, but the complexity of the tip assembly increases

Engineering Contradiction:

Improveexpansion diameterVSAvoidtip assembly complexity

Core Design Contradiction:

Area of moving objectVSDevice complexity

Solution Approach 1:

The distal tip assembly is segmented into a flap portion and a body portion, with the flap configured to articulate relative to the body. This segmentation allows the flap to expand outward to enhance the expansion diameter for device retrieval, while the modular segmented structure actually reduces overall complexity by allowing independent optimization of each segment's function.

Inventive Principle:

Principle #1Segmentation

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 sheath enables safe and efficient delivery of prosthetic devices by reducing vessel damage and plaque dislodgment, while maintaining visibility and preventing leaks, thus enhancing procedural safety and efficiency.

Implementation Method 1

an outer elastomeric member extending around the inner member and configured to exert a compressive force onto the inner member to bias the inner member into the folded configuration

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

configured to be highly expandable and collapsible in the circumferential direction, while also minimizing the wall thickness of the sheath to minimize the profile of the delivery system

Methodology Applied

Scientific EffectElastic compression: Elasticity

Data Source

PatentUS20260026935A1Expandable sheath and methods of using the same

Publication Date: 2026.01.29 EDWARDS LIFESCIENCES CORP

AI summary

Disclosed herein are expandable introducer sheaths and methods of making and using the same. The sheaths minimize trauma to a patient's vasculature by allowing for temporary expansion of a portion of the sheath to accommodate passage of a delivery system for an implant, then return to a non-expanded state after the passage of the device. The sheath includes a foldable inner member having a detached flap structure at its distal tip that facilitates expansion of the sheath lumen to increased diameters, and an elastomeric distal end that reduces push and retrieval forces therethrough. The sheath can include a hemostasis seal on its proximal end to prevent the leakage of blood out of the sheath and prevent ballooning of outer layer of the sheath.