Split Sheath Introducer Using Coextruded Elastomer Stripes

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Solution Overview

Problem

Existing peelable introducer sheaths face challenges such as difficulty in initiating a clean tear, propensity for jagged tears, high cost due to material usage, and issues with maintaining a round shape and minimizing tackiness, which have hindered the development of a reliable and effective splittable sheath for medical device insertion.

Innovation Solution

A splittable introducer sheath is manufactured using a coextrusion process with a tubular body formed from medium-density polyethylene or high-density polyethylene modified with a friction-reducing additive, combined with thermoplastic elastomer stripes modified with a siloxane additive, allowing for easy longitudinal splitting while resisting inadvertent splitting and maintaining a round shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If polypropylene or polyethylene tubing with a score line is used, then the sheath can be peeled apart, but tearing or peeling is difficult to initiate and produces a jagged tear

Engineering Contradiction:

Improveease of peelingVSAvoidcleanliness of tear

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent uses a composite structure consisting of a main body material (polypropylene or polyethylene) and a stripe material (Teflon or other low-friction material) that is easier to tear. The stripe material is bonded to the main body along longitudinal stripes, creating a composite structure where the weaker stripe initiates and guides the tear through the entire sheath wall thickness, producing a clean linear tear instead of a jagged one.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If Teflon is used for the sheath, then the sheath tears linearly without needing a score line, but the material is expensive

Engineering Contradiction:

Improveease of tearingVSAvoidmaterial cost

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

Instead of making the entire sheath from expensive Teflon, the patent applies Teflon or similar low-friction material only as thin longitudinal stripes (approximately 1-5 mm wide) on the outer surface of the sheath. This localized application provides the necessary tearing properties and lubricity only where needed, while the majority of the sheath is made from cheaper polypropylene or polyethylene material.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If stripes of different material are used to enable easy peeling, then the sheath can be peeled along the stripe/main body interface, but the stripes may inadvertently detach during insertion

Engineering Contradiction:

Improveease of peelingVSAvoidattachment strength

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The stripe material is pre-bonded to the main body material using adhesives or other bonding mechanisms before the sheath is sterilized and packaged. This preliminary bonding ensures the stripes remain firmly attached during storage, sterilization, and insertion procedures, while still allowing easy peeling along the stripe/main body interface when needed for device removal.

Inventive Principle:

Principle #10Preliminary action

4Ease of operation

If the sheath is made internally lubricous to allow easy device insertion, then devices can slide through easily, but the sheath may become tacky and stick

Engineering Contradiction:

Improveease of device insertionVSAvoidtackiness

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the friction characteristics of the sheath by incorporating low-friction materials (such as Teflon/PTFE) as longitudinal stripes on the outer surface. These stripes provide lubricity that facilitates device insertion and removal while the controlled geometry and material properties prevent excessive tackiness or sticking during storage and handling.

Inventive Principle:

Principle #35Parameter changes

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 solution enables a sheath that is easily split when needed, resists inadvertent splitting during insertion, and maintains a substantially round shape with minimal tackiness, addressing the limitations of existing sheaths and providing a reliable and efficient means for medical device insertion.

Implementation Method 1

Methodology Applied

Scientific EffectCoextrusion: Extrusion

Implementation Method 2

The first material is one of a medium-density polyethylene modified with a friction-reducing additive or high-density polyethylene (HDPE) modified with a friction-reducing additive

Methodology Applied

Scientific EffectFriction reduction: Friction

Implementation Method 3

thermoplastic elastomer stripes modified with a siloxane additive, allowing for easy longitudinal splitting while resisting inadvertent splitting

Methodology Applied

Scientific EffectMaterial modification:

Data Source

PatentUS12042612B2Split sheath introducer and method of manufacturing a split sheath introducer

Publication Date: 2024.07.23 ARGOS CORP

AI summary

A splittable introducer sheath includes a tubular body portion formed from a first material and at least one stripe extending an entire length of the main body portion, the at least one stripe being formed form a second material. The first material is one of a medium-density polyethylene modified with a friction-reducing additive or high-density polyethylene (HDPE) modified with a friction-reducing additive. The second material is a thermoplastic elastomer modified with a siloxane additive. The sheath is dividable longitudinally along the at least one stripe.