Catheter tubing with improved stress-strain characteristics

Abstract

A medical tubing is disclosed which includes a first material extending between proximal and distal ends of the tubing and which defines a lumen of the tubing. The tubing also includes a second material extending between at least portion of the distance between the proximal and distal ends of the tubing and that is embedded in the first material. The second material is fractured. The first material is flexible and the second material is relatively rigid and brittle and the two materials combined to provide a medical tubing that exhibits strain softening behavior.

Description

BACKGROUND [0001] 1. Technical Field [0002] An improved intravascular catheter is disclosed. More specifically, an improved catheter is disclosed that provides improved stress-strain behavior that exhibits a sufficient degree of stiffness at low cross-axial strains for sufficient pushability, and sufficient flexibility at higher cross-axial strains for sufficient trackability. [0003] 2. Description of the Related Art [0004] Intravascular catheters are widely used for a variety of diagnostic and therapeutic purposes. Specifically, angioplasty has been developed as an alternative to bypass surgery for treating vascular diseases or other conditions that occlude or reduce blood flow in a patient's vascular system. Balloon angioplasty has proven to be a useful and often a preferred treatment for coronary diseases that cause blockages, also known as stenosis, in coronary arteries as well as other parts of the vascular system. [0005] Advancing the catheter assembly to position the balloon ...

AI Technical Summary

Benefits of technology

The strain softening tubing reduces the force required to navigate tortuous paths, increases buckling strength, and minimizes guide catheter back-out, while maintaining flexibility, thereby enhancing the effectiveness of medical procedures by ensuring stable fluid communication and reduced kinking.

Problems solved by technology

Advancing the catheter assembly to position the balloon across a stenosis can be a difficult and time consuming task due to the narrow and tortuous vascular passages through which the catheter assembly must be passed.

One problem associated with connecting a relatively stiff tubular member, such as a hypotube, to a more flexible tubular member, such as the catheter, is that the transition between the stiff hypotube and the more flexible catheter can result in kinking which can close the lumen of the hypotube or the lumen of the catheter thereby blocking flow through these lumens to the balloon.

Furthermore, it is known that when the force (Fs) on a given length of tubing (1) exceeds a certain critical value (Fsc), the tubing will buckle or collapse and thus limit both the trackability, force transmission of the catheter and fluid communication through the catheter:

In addition, a high flexural modulus (Eb) can produce excessive counteractive force, producing guide catheter back-out.

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