Ultra Soft Catheter Tip Using Composite Durometer Materials

Solution Overview

Problem

Intravascular balloon catheters with hard distal tips can cause unnecessary trauma to diseased vessel walls during navigation, as they lack the necessary softness to minimize injury during medical procedures.

Innovation Solution

An intravascular balloon catheter with an ultra soft distal tip is designed, featuring a braided reinforcement layer covered with a polymer layer and an inflatable balloon made of highly compliant thermoplastic rubber elastomer, extending beyond the distal end to create a soft tip with a durometer hardness of 5-40 Shore A, reducing vessel wall injury.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the distal tip is made hard for structural support, then the catheter maintains stiffness for navigation, but the vessel wall is injured during insertion

Engineering Contradiction:

Improvecatheter stiffnessVSAvoidvessel wall trauma

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The catheter employs different durometer materials at different locations: the shaft uses a harder material (55-70 Shore D) for structural support and trackability, while the distal tip uses a softer material (35-55 Shore D) to minimize vessel wall trauma. This local differentiation of material properties resolves the contradiction between needing stiffness for navigation and softness for safe insertion.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The catheter is constructed as a composite structure with multiple polymer layers having different durometer properties. The combination of harder shaft material and softer tip material creates a composite catheter that simultaneously provides the stiffness needed for structural support and the softness required to prevent vessel wall injury during navigation and insertion.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If the distal tip is made soft to reduce vessel wall injury, then trauma is minimized, but the catheter loses trackability through the vasculature

Engineering Contradiction:

Improvevessel wall traumaVSAvoidcatheter trackability

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The catheter employs different durometer materials at different locations: the shaft uses a harder material (55-70 Shore D) for structural support and trackability, while the distal tip uses a softer material (35-55 Shore D) to minimize vessel wall trauma. This local differentiation of material properties resolves the contradiction between needing stiffness for navigation and softness for safe insertion.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The catheter is constructed as a composite structure with multiple polymer layers having different durometer properties. The combination of harder shaft material and softer tip material creates a composite catheter that simultaneously provides the stiffness needed for structural support and the softness required to prevent vessel wall injury during navigation and insertion.

Inventive Principle:

Principle #40Composite materials

3Ease of operation

If the catheter profile is reduced for better navigation, then access to remote regions is improved, but the structural support is compromised

Engineering Contradiction:

Improvenavigation capabilityVSAvoidstructural support

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The catheter employs a thin-walled elastic balloon (0.002-0.006 inches wall thickness) that provides structural support and radial force during procedures while maintaining a low overall profile. The thin-walled construction allows the catheter to navigate through the vasculature effectively while the elastic properties of the balloon material provide necessary structural integrity when inflated.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The catheter is constructed as a composite structure with multiple polymer layers having different durometer properties. The combination of harder shaft material and softer tip material creates a composite catheter that simultaneously provides the stiffness needed for structural support and the softness required to prevent vessel wall injury during navigation and insertion.

Inventive Principle:

Principle #40Composite materials

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 ultra soft distal tip minimizes trauma to the vessel wall, allowing for safe navigation and treatment while maintaining the necessary stiffness and flexibility for effective blood flow arrest during medical procedures.

Implementation Method 1

The material of the inflatable balloon and the distal tip is preferably a highly compliant polymer such as a thermoplastic rubber elastomer, providing the catheter with an ultra soft distal tip

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS7815599B2Catheter having an ultra soft tip and methods for making the same

Publication Date: 2010.10.19 BOSTON SCIENTIFIC SCIMED INC

AI summary

An intravascular balloon catheter having an ultra soft tip. The catheter includes a braided reinforcement member extending substantially the length of the elongate shaft. A balloon is disposed at the distal end of the elongate shaft. An ultra soft tip is formed from a distal portion of balloon material extending distal of the distal end of the elongate shaft.