JPH02184419A - Manufacture of catheter - Google Patents

Abstract

PURPOSE:To make a boundary between a top and a body clear by removing mixture of a top material and a body material near the boundary between the top and the body by a method wherein a soft material block composing the top and a hard material block composing the body are inserted into an extruding tool, and the soft material and the hard material are in turn extruded by a narrow diameter. CONSTITUTION:A block 1 composed of, for instance, urethane elastomer as a soft material composing a suitable rigid suitable flexible top part, and a block 2 composed of, for instance, thermotropic liquid crystal polymer as a hard material composing a rigid body part are inserted into a cylinder 10 of an extruder. After melting the blocks 1, 2 by heating, both blocks 1, 2 are in turn molded by extrusion from a narrow diameter opening 11 with a plunger 12 established to one side of the cylinder 10, and a narrow diameter catheter is manufactured.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a catheter.

[Conventional technology]

Catheters are generally inserted into blood vessels (particularly coronary arteries), tracheas, fallopian tubes, ureters, etc., and various organs, and are used for the purpose of injecting or suctioning fluids, or ensuring patency of passages.

Common requirements for catheters are that the main body has enough rigidity to mainly transmit torque such as rotation, and the distal end has appropriate rigidity and appropriate flexibility.

It is desirable that the main body is capable of transmitting torque when the proximal end of the catheter main body is rotated around its axis, such as when changing the direction of the distal end of the catheter at the insertion point of a surface tube or organ. This is because it is convenient for the main body to have the function of efficiently transmitting the rotation 1 to 1 torque to the distal end.

In addition, the tip requires appropriate rigidity and flexibility, because if the tip is not flexible, the tip will not respond to the desired rotational torque when changing the insertion position of the catheter. This is because the direction and angle of the catheter cannot be easily followed as the main body rotates, and there is a risk of damaging the tissue of blood vessels and organs when inserting the catheter. On the other hand, if it is too flexible and lacks rigidity, it will be difficult to insert it smoothly into the various organs of the human body.

[Problem to be solved by the invention]

There are various methods of manufacturing a catheter having a rigid main body portion, appropriate rigidity, and appropriate flexibility at the distal end portion as described above.
1) Separately manufacture a main body with 1 lil'l properties and a tip with appropriate rigidity and appropriate flexibility, and then join the main body and the tip with adhesive or heat fusion, or ■Manufacturing methods include forming the organic polymer composition that is the material of the catheter into a small diameter by extrusion molding, etc., and then post-processing the tip and main body to give the necessary flexibility and rigidity. Common.

However, it is difficult to precisely join the main body and the distal end with the manufacturing method (1).As is well known, if the joining boundary between the main body and the distal end is not smooth, turbulence will occur in the liquid flowing inside the catheter. However, in such a case, it is unsuitable for use as a catheter, so the main body and tip must be precisely joined together to prevent turbulence as much as possible, but in the manufacturing method of (2), they are in a separated state. "Construction in which the main body and the distal end are joined to form an integrated catheter"--Difficulty in joining is inevitable.

The manufacturing method (2) solves the difficulty of joining, and can manufacture a catheter in which the main body and the distal end are integrated, but it requires a post-processing process, which makes manufacturing the catheter that much more troublesome.

Furthermore, there is a manufacturing method described in Canadian Patent No. 093071 as an improvement on the manufacturing method (2).

In order to eliminate the need for cleaning and post-processing, a first plastic material having predetermined physical properties (mainly flexibility, etc.) that will become the tip is inserted into the first extruder, and the main body is A second plastic material having predetermined physical properties (such as rigidity) is inserted into the second extruder, and the material in the first extruder is first extruded, and after a certain time interval, the material in the tip is introduced. The catheter is extruded by decreasing the flow rate from the first extruder containing the body material while proportionately increasing the flow rate from the second extruder containing the body material.

However, in this manufacturing method, since the 11th plastic material and the 2nd plastic material are sequentially increased or decreased, the boundary between the tip and the main body is not clear, and the shape 11- is a mixture of both plastic materials.

A catheter having such a structure is not preferable because the rigidity of the main body, which is originally required for a catheter, is reduced, and the flexibility of the distal end is also reduced.

Therefore, the object of the present invention is to obtain the above-mentioned Canadian patent no.
The object of the present invention is to provide a novel method for manufacturing a catheter that solves the drawbacks of the method disclosed in No. 1.

[Means for Solving the Problems] In order to achieve the above object, the method for manufacturing a catheter of the present invention includes a block of hard material constituting the main body portion and a block of soft material constituting the distal end portion continuous to the main body portion. The invention is characterized by inserting the two into one extrusion tool, and sequentially extruding a soft material and a hard material to a small diameter from within the tool.

In the catheter manufacturing method of the present invention, the soft material and the hard material are not extruded using two extruders by gradually increasing acidity, but the soft material and the hard material are completely separated in one extruder. Since the tip is inserted and then extruded one after another in a separated state, the boundary between the tip and the main body is clear, which solves the inconvenience caused by the manufacturing method disclosed in the Canadian Patent No. 2.

Therefore, the hard material constituting the rigid main body is not particularly limited as long as it can be inserted into the human body, and may include Thermo 1-〇 pink liquid crystal polymer, polyamide resin, polyoxymethylene, polycarbonate, polybutylene thirefthalene, etc. 1~,
polyphenylene sulfide], polyether sulfone,
Examples include polyarylate, polyetheretherketone, polyamideimide, and polyetherimide.

In addition, there are no particular limitations on the soft material constituting the tip with appropriate rigidity and flexibility as long as it can be inserted into the human body.
Examples include polyurethane elastomer, polystyrene elastomer, 12-polybucdiene elastomer, polyester elastomer, polyamide 1-based elastomer, chlorinated polyethylene elastomer, polyvinyl chloride resin, polyethylene, and ethylene-vinyl acetate copolymer. be done.

Note that a small amount of the soft material that makes up the tip may be added to the hard material that makes up the main body, or conversely, a small amount of the hard material that makes up the main body may be added to the soft material that makes up the tip. .

Furthermore, the soft tip 644 may contain an X-ray contrast agent such as barium sulfate, bismuth oxide, gold, platinum, silver, iridium, tantalum, tungsten, or molybdenum.

In the present invention, there are no particular limitations on the equipment used for extrusion molding. For example, a cylinder may be used as an extrusion tool for inserting a block of soft material and a hard material, and a catheter of a predetermined diameter may be manufactured by combining the cylinder and plunger, such as using a plunger to extrude the art material in the cylinder to a small diameter.

When manufacturing only one catheter, it is sufficient to insert one block of soft material and one block of hard material, but when manufacturing multiple catheters at once by continuous extrusion molding. To do this, blocks of art material are inserted alternately into a tool and extruded in order to form a small diameter catheter in succession. Then, if necessary, it may be further cut to a predetermined length.

In addition, regarding the cross-sectional shape of catheters, recent catheters have been developed with the advancement of medical technology, and in addition to the usual injecting and suction of liquids and ensuring passage patency, catheters are equipped with illumination fibers for endoscopy and imaging. There are guides and even "Sorantsuyu Kongi", making them multi-functional. Such multifunctional catheters require holes that correspond to their functions.
The cross-sectional shape becomes fine and complicated. It is important to manufacture a catheter with a fine cross-sectional shape using a die or the like that matches the shape.

Next, a specific method for manufacturing the catheter will be outlined.

FIG. 1 shows the case where only one catheter is extruded. A soft material block 1 constituting the tip and a hard material block 2 constituting the main body are inserted into a cylinder 10 which is an extrusion molding tool, and a plunger 12 provided on one side of the cylinder 10 allows both +A ], 2 are sequentially extruded from the small diameter port 11 to produce one small diameter catheter.

FIG. 2 shows the case where 2n catheters are continuously extruded at one time. Inside the cylinder 20, there are blocks l of soft 1 corresponding to 2n pieces, , ], , . . . IL, , 1. ,,,
and hard material blocks 2I1.2b, . . . 2, . 2 degrees, and similarly, the plunger 22 provided on one side of the cylinder 20 sequentially pushes out the art material from the narrow opening 21 to produce 20 continuous narrow catheters. Thereafter, each catheter is separated from the middle part of the main body part and the intermediate part of the tip part other than the tip parts at both ends, and if necessary, each catheter is further cut to a desired length.

[Example] Hereinafter, the method for manufacturing a catheter of the present invention will be explained based on Examples.

A block made of urethane elastomer is used as the soft material that makes up the tip with appropriate rigidity and flexibility (length: 2 mm, outer diameter: 5 mm), and thermodropink is used as the hard material that makes up the rigid main body. ? A block 2 made of night crystal polymer (length: 3 mm, outer diameter: 5 mm) is inserted into a cylinder 10 with an inner diameter of approximately 8M in an extrusion device as shown in FIG. 1, and the block 1.2 is melted by heating. After that, both blocks 1.2 are extruded into a plunger 12 provided on one side of the cylinder 1.1 10, starting from the small diameter port 11 with a diameter of about 4.5 mm. A catheter was manufactured.

〔Effect of the invention〕

As explained above, the method for manufacturing a catheter of the present invention includes inserting a block of soft material constituting the distal end portion and a block of hard material constituting the main body portion into one extrusion tool,
Since the soft material and hard material are sequentially extruded from inside the tool into small diameters, the art materials do not mix near the boundary between the tip and the main body, and the boundary between the tip and the main body is clear. Disadvantages due to the manufacturing method disclosed in the national patent (
The problems that are originally required for catheters, such as lowering the rigidity of the main body and lowering the flexibility of the distal end, can be solved.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an example of the method for manufacturing a catheter according to the present invention, and FIG. 2 is a schematic explanatory diagram showing an example of the method for manufacturing a catheter according to the present invention. I, 1,1 b 1°, block of soft material 2. 2.1 b 2.1 2, l: Hard phase block 10.20 Nijilinda 12.22: Plunger

Claims (1)

[Claims] A block of hard material constituting the main body and a block of soft material constituting the tip continuous to the main body are inserted into one extrusion tool, and the soft material and the hard material are sequentially extruded to a small diameter from within the tool. A method for manufacturing a catheter, comprising: