Medical tubing having variable characteristics and method of making same

Abstract

The invention primarily is directed to a medical tubing adapted for insertion into a body tissue or cavity and method of manufacturing different variations of the tubing along a length of the tubing. The tubing comprises a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused or bonded together forming a continuous tubular structure. The ring-shaped elements may be formed of a thermoplastic or a thermoset material. The ring-shaped elements may include plastic rings, metallic rings, un-reinforced plastic rings and/or metal reinforced plastic rings assembled along the length of the tubular structure to provide variable flexibility and kink-resistance. The tubular structure may have a cross-section of any geometric shape and it may be bent, twisted or curved without kinking. The ring-shaped elements may have different flexural modulus. The ring-shaped elements may include a combination of flexible and rigid ring-shaped elements assembled along different portions or sections of the tubular structure. The ring-shaped elements may be metallic and may be bonded with a resilient, flexible elastomeric adhesive, wherein the ring-shaped elements may have different lengths and may be fused closer or further apart to one another depending on the characteristics of a portion or section of the tubing. In another aspect of the invention, the medical tubing may further comprise a secondary lumen and a pull wire to control the tubular structure. The ring-shaped elements may be truncated to provide a bending bias. In another aspect of the invention, the ring-shaped elements may vary in diameter and/or composition in different portions or sections of the tubular structure. In yet another aspect of the invention, some of the ring-shaped elements may be radiopaque, or the ring-shaped elements may comprise of different colors to operate as indicators along the tubular structure.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention generally relates to medical devices and, more specifically, to medical tubing adapted for insertion into a body tissue or cavity having variable characteristics and method of making same. [0003] 2. Discussion of Related Art [0004] Medical tubing includes tubing used as catheters, drain tubes, access ports, endoscope bodies and the like. The requirements for each type of medical tubing will depend on its use. In particular, a specific length of medical tubing may vary depending on each application. For example, a specific length of medical tubing may need to be very flexible and yet pushable, or it may need to be thin-walled and yet kink-resistant. In addition, the tubing may need to exhibit these properties in only specific regions. [0005] Most medical tubing is extruded from a single plastic material in a continuous forming process. Certain characteristics or variations may be imparted to the extrud...

AI Technical Summary

Benefits of technology

[0012] In another aspect of the invention, a method of manufacturing a thin-walled tube is disclosed comprising the steps of coating a wire with a plastic material, wrapping the coated wire around a mandrel forming a plurality of windings, and heating the wound coated wire until the plastic material melts and bonds the windings forming a wire-reinforced tube. In this method of the invention, the plastic material may comprise at least one of polyurethane, a thermoplastic material and a thermoset material. In another aspect of the invention, the wire may comprise at least one of a metallic material and a second plastic material, or the wire may be coated with the plastic material in a coextrusion process. This method of the invention may further comprise the step of compressing the windings as the coated wire is being heated.

[0013] In another aspect of the invention, this method may further comprise the step of providing a mold to compress the windings. This method may further comprise the step of removing the wire-reinforced tube from the mandrel after the tube is cooled. The wound-coated tube may also be heated until the plastic material is formed above, below and between all the windings. This method may further comprise the step of dipping the tube in a solvent-based solution forming an outer layer of the tube. In other aspects of the invention, the mandrel may be tapered to provide the tube with varying diameter throughout the length of the tube, the coated wire may be alternatively wound with the filament around the mandrel, the mandrel may be any shape such that the resultant shape of the tube may be removed from the mandrel after the heating step, and the mandrel may be a multiple-part mandrel.

[0014] In another aspect of the invention, a method of manufacturing a kink-resistant thin-walled tube having a length with different characteristics is disclosed, the method comprising the steps of coating a mandrel with a first layer of plastic material, placing a spring reinforcement over the first layer, and coating the spring reinforcement with a second layer of plastic material to form a spring-reinforced tube. In this method of the invention, each of the first layer and the second layer may be formed in either an extrusion process or a molding process. The spring reinforcement of the invention may be a pre-wound wire comprising at least one of a metallic material and a second plastic material. The method of the invention may further comprise the step of dipping the tube in a solvent-based solution forming an outer layer of the tube.

Problems solved by technology

However, the variations are limited by the fact that a single material is extruded.

Nevertheless, this is still a linear process and is still limited by the continuous flow of the extruded materials.

Kink-resistance with very thin walls is not obtainable through the current extrusion processes.

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