JPH02280765A - Catheter, its manufacture and catheter device - Google Patents

Abstract

PURPOSE:To properly provide the flexibility and rigidity in the longitudinal direction without using the reinforcement by jointing or braiding by installing two units of extruders for feeding resin into each extrusion head and feeding soft material and hard material under pressure, in the continuous extrusion molding of thermoplastic resin. CONSTITUTION:Soft resin 1a is extruded from an extruder 10a, and hard resin 1b is extruded from an extruder 10b, and both kinds of resin pass through the feeding passages 11A and 11B, and sent into the A port and B port of a mixing control valve 12. The resin is sent through a mixing control hole 13C into a C port having an extrusion outlet 14 which communicates to an extrusion head 14 from the mixing control holes 13A and 13B from a rotary spool 13 in a three directional slide cock form in the control valve 12. The feeding ratio into an extrusion head 15 for the soft resin 1a and hard resin 1b is controlled by properly revolving the rotary spool 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel catheter having a soft portion integrally formed at the distal end portion that directly contacts an organ, and a method and apparatus for manufacturing the same.

[Prior Art J Catheters are generally made of tubes made of rubber, plastic, etc., and are widely used for diagnosis, examination, treatment, etc. in blood vessels, digestive organs, tracheas, urethra, etc.

In particular, catheters used to inject drugs into blood vessels, reach the heart to measure pressure, or expand and pass through narrowed blood vessels must be accurately introduced to the desired location. The insertion maneuverability is required. For this reason, the tip of the catheter must be flexible enough to bend freely to accommodate the bending of the blood vessel, etc., while the main body must be rigid enough to transmit the pushing force to the tip. This means that contradictory properties such as flexibility and rigidity are required.

In order to provide these characteristics, conventionally the rigid catheter body and the flexible distal end were manufactured separately from different materials, and then joined together by heat fusion, solvent bonding, adhesive bonding, etc. was.

However, when this joining method is used, it is difficult to accurately butt the lumens of the catheter against each other, a step is formed on the outer surface that prevents smooth insertion, and the catheter is damaged at the joint during use. There is a risk that this may occur.

Therefore, instead of the above bonding method, a method of reinforcing metal braid by embedding it has been proposed. In this method, the catheter itself is made of a soft material that is easy to bend, and the tip portion is left as is, and the main body portion is reinforced with a braid to provide the necessary rigidity.

[Problems to be Solved by the Invention] Although the problems in the above-mentioned joining method are solved by performing braid reinforcement, the following problems still remain that need to be solved.

First, braided catheters are complicated to manufacture and costly.

Furthermore, there is a risk that the braided metal wires may protrude into the inner lumen or outer surface of the catheter, and sufficient management is required to prevent this.

Also, just because the tip of a catheter is flexible, it does not mean that the body side has the same rigidity; it is even more desirable that the rigidity in the longitudinal direction changes gradually during insertion. However, braiding eliminates such arbitrary changes. It is very difficult to give.

The object of the present invention is to solve the problems of the prior art as described above, and to develop a new method that can appropriately provide flexibility and rigidity in the longitudinal direction without using a joining method or reinforcing by braiding. It is an object of the present invention to provide a catheter and a method and apparatus for manufacturing the same.

[Means for Solving the Problems] The present invention comprises a catheter made of a continuous extrusion molded body of thermoplastic #M resin, and has a soft part made of a soft material itself in the longitudinal direction, and a hard part made of the material itself in the longitudinal direction. The first point is to have a structure having a hard part made of material, and when extruding the tube of the catheter, two extruders are installed to supply resin to the extrusion head,
A soft material is supplied from one extruder and a hard material is supplied from the other extruder under pressure, and by selectively changing the mixing ratio of the supplied resin at the extrusion head part, a soft part and a hard part are produced in the longitudinal direction. The second gist is an extrusion manufacturing method for continuously extrusion molding a tube having A three-way slip-type rotary spool is arranged within the control valve,
The third aspect is an apparatus configured to selectively conduct material from one or both of the two supply paths to the extrusion head by rotating the rotational sprawl.

[Function] It is possible to obtain a catheter in which the necessary flexibility and rigidity are distributed in the longitudinal direction without forming a soft part and a hard part by using different materials during extrusion, or by joining or braiding.

During this extrusion, if two extruders, a soft material extruder and a hard material extruder, are used and the mixing ratio of both materials in the extruded product can be selectively changed, flexibility and rigidity in the longitudinal direction of the catheter can be freely adjusted. This makes it possible to manually create innovative products that change the rigidity of the intermediate portion.

[Example] The present invention will be described below with reference to Examples. Fig. 1 is an explanatory diagram showing m1ffl of a catheter 1 according to the present invention, and the entire body is integrally extruded from thermoplastic resin. ing. However, the tip side is made of soft resin l.
a itself is configured as a soft part, and the main body side is a hard part vI4
@1b itself constitutes a hard part, and these soft part and hard part are molded as one piece.

Note that low-density polyethylene (LDPE: density = 0.922, MI = 1.0) is suitable as the soft resin, and high-density polyethylene (HDP) is suitable as the hard resin.
E: Density = 0.942, MI = 0.2) is suitable, and these are HDPE: LDPE = 100:
The mixture ratio can be continuously varied from O to 50:50 to O:100, and can be extruded into catheter tubes with outer diameters from 1.3 to 2.7.

Suitable soft resins other than those mentioned above include soft PVC (polyvinyl chloride), PE (polyethylene), PVC, etc., and hard resins include hard PVC and fluorinated resins such as vinylidene fluoride. I can give it to you.

In the combination of hard resin and soft resin, there is no problem whether the resins are of the same type or different resins.

The hard part 1b may have a structure in which the rigidity is changed, so that the stiffness is higher on the base side and the flexibility is gradually added toward the distal side, thereby greatly improving the maneuverability of inserting the catheter. This is something that can be improved.

According to the catheter having the above structure according to the present invention, since the soft part and the hard part are continuously extruded without a joining part, the problem of the joining part in the conventional example does not exist.
In addition, there is no need to use braid to provide rigidity.
Since the rigidity is dependent on the properties of the material itself, there is no problem with using the above-mentioned lit cap.

FIG. 2 is an explanatory diagram showing a specific apparatus for manufacturing the catheter 1 according to the present invention configured as described above.

In the present invention, two extruders are installed, and the - extruder 10A extrudes a soft resin 1a that can provide the catheter with the necessary flexibility, and the extruder 10B extrudes a hard resin that has the necessary rigidity. 1b are extruded, and each feed channel 1
1A and IIB, the respective resins 1a and 1b are connected to the A port and B port of the mixing control valve 12.
sent out on a boat.

Inside the control valve 12 is a rotating spool 13 in the form of a three-way plug, the A boat has a mixing control hole 13A, the B boat has a mixing control hole 13B, and an fM@ outlet communicating with the extrusion head 14. Mixing control holes 13C are arranged in the C ports having 14, and the respective control holes communicate with each other. By appropriately rotating the rotating spool 13 as described later, the mixture of the soft resin 1a and the hard VI resin 1b is mixed. The configuration is such that the supply ratio to the extrusion head 15 can be controlled and changed.

Below, the above-mentioned supply ratio control means will be explained using FIGS. 3 to 5.

FIG. 3 shows that when the rotating spool is rotated, the supply passage 11B and the mixing control hole 13B in the B boat are fully open, while the supply passage 11A and the mixing control hole 13 in the A boat are fully open.
It is an explanatory view showing a state where A is in a fully closed state. In this state, only the hard resin 1b can pass through the control valve 12, and only the hard resin 1b is supplied from the C boat to the extrusion head 15.

FIG. 5 is an explanatory diagram showing a state in which the rotary spool 13 is rotated so that the relationship is opposite to that described above. In this state, the supply of the hard resin 1b is stopped, and only the soft resin 1a is supplied to the extrusion head 15.

FIG. 4 is an explanatory diagram showing a state in which the rotary spool 13 is rotated to an intermediate position in FIGS. 3 and 5 described above. In this state, the supply channels 11A and IIB and the mixing control holes 13A and 13B are connected to the A port and the B boat, respectively.
is in a partially communicating state, and the soft resin 1a and hard resin 1b are mixed according to the degree of opening, and in this mixed state l
! l@ is supplied to the extrusion/Ydo 15.

When the distal end portion of the catheter 1 is to be molded, the rotary spool 13 of the control valve 12 is placed in the state shown in FIG. 5, and only the highly pliable soft resin 1a is extruded. In this way, once the required length of the soft part is molded, the rotary spool 13 is rotated to the state shown in Figure 4, the rigidity is gradually increased by mixing the soft resin 1a with the hard resin 1b, and finally the molded part is molded as shown in Figure 3. Rotate the rotating spool 13 in the direction of hardness! Only the resin 1b is extruded to form the tail side of the main body, which has greater rigidity.

In this way, it is possible to easily obtain a catheter according to the present invention in which the catheter itself is formed as an integral extrusion molded product, and which has the necessary flexibility and flexibility in the longitudinal direction for the necessary length. .

Note that the means for mixing the soft resin 1a and the hard resin 1b is not limited to the control valve method described above, and the respective supply channels 11A.

There is no problem in using appropriate means such as providing a valve that can separately adjust the supply of each resin in the middle of 11B, or a cylinder for stirring the mixed resin may be provided in the middle.

Furthermore, regarding the supply of the soft resin 1a and the hard resin @1b, it is not necessary to always perform the operations shown in Figures 3 to 5 above, but the necessary characteristics can be obtained by changing only the mixing ratio in the state shown in Figure 4. There is no harm in trying to obtain .

[Effects of the Invention] As described above, according to the present invention, catheters with excellent operability can be mass-produced at low cost by freely changing the material during extrusion, and in practical use, there are no joints or metal braids. It can fully demonstrate the advantages of this, and its usefulness is extremely large.

[Brief explanation of drawings]

FIG. 1 is an explanatory sketch of the catheter according to the present invention, FIG. 2 is an explanatory diagram of the manufacturing apparatus thereof, and FIGS. 3 to 5 are explanatory diagrams showing the operation status of the control valve. 1: Catheter, 1a: Soft resin, 1b: Hard resin, 10A: Soft resin extruder, 10B: Hard resin extruder, 11A: Soft resin supply path, 11B: Hard resin supply path, 12: Mixing control valve, 13 : Rotating spool, 13A, 13B, 13C: Mixing control hole 14: 4ai fat outlet, 15: Tube extrusion head, A, B, C: Boat. Figure 11 Figure 2

Claims (3)

[Claims] (1) The entire body is composed of a continuous extrusion molded body of thermoplastic resin, and has a soft part made of a soft material itself and a hard part made of a hard material in the longitudinal direction. A catheter made up of (2) When performing tube extrusion, two extruders are installed to supply resin to the extrusion head, and one extruder supplies a soft material and the other extruder a hard material under pressure. An extrusion manufacturing method in which a tube having a soft portion and a hard portion in the longitudinal direction is continuously extruded by selectively changing the mixing ratio of the resins supplied in the head portion. (3) Two supply channels from two extruders are communicated with one control valve, a three-way slip-shaped rotary spool is placed in the control valve, and the rotary spool is rotated. An extrusion manufacturing apparatus configured to selectively conduct materials from one or both of two supply paths to an extrusion head.