JP2001321445A - Flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube suitable for a multilumen catheter tube, which is capable of simultaneously meeting characteristic requirements of thrusting property, torque transmission performance and follow-up ability. SOLUTION: The flexible tube 1 is provided with a approximately circumferentially rounded flexible inner tube 3 having a plurality of lumens 10 each being opened at both ends in an axial direction A and not communicating each other, a reinforcing material layer 5 having a reinforcing material 12 formed by braiding single or a plurality of wires 11 into a net on the surface of the inner tube 3 and each wire 11 forming an angle varying gradually or continuously almost along the axial direction A, and a reinforcing layer intervention part 2 including an approximately cylindrical flexible outer tube 4 fixed on the outer side of the inner tube 3 via the reinforcing material layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flexible tube suitable for a medical multi-lumen catheter tube.

[0002]

2. Description of the Related Art Flexible tubing used for medical catheters is roughly divided into a single lumen catheter tube having one lumen and a multi-lumen catheter tube having a plurality of lumens. Since the multi-lumen catheter tube is formed so that a plurality of lumens do not communicate with each other, injection of an angiographic agent or a drug solution, injection of gas for inflating a balloon attached to the distal end portion, forceps, laser Fiber introduction and the like can be performed with a single tube.

[0003] Such a flexible tube for a catheter is rapidly and percutaneously, nasally or orally injected into a thin and complicated pattern of a body cavity (blood vessel, ureter, fallopian tube, bile duct, pancreatic duct, etc.). In addition, since excellent operability that allows insertion with reliable selectivity is required, it is necessary to simultaneously satisfy the following characteristics (1) to (3). (1) Pushing force by which the operator's pushing force to penetrate the blood vessel can be reliably transmitted from the proximal end to the distal end of the catheter on the operator's hand side. (2) Applied at the proximal end Torque transmission so that torque can be reliably transmitted to the distal end. (3) Followability such that it can proceed smoothly in a curved blood vessel along a preceding guide wire without damaging the blood vessel inner wall.

In order for a flexible tube for a catheter to simultaneously satisfy all of the above-mentioned properties of pushability, torque transmission and followability with a single tube, the bending stiffness changes along the axial direction of the tube. It is required that the bending stiffness generally decreases from the base end side toward the distal end side. In the case of a single lumen catheter tube, for example, a catheter tube satisfying the above requirements can be realized by joining two or more types of tubes having the same diameter and different hardnesses in the axial direction.

[0005]

However, in order to realize a multi-lumen catheter tube by joining the tubes as described above, two or more kinds of tubes having a plurality of lumens and different in hardness from each other have the same diameter. Therefore, it is difficult to maintain the shape of the lumen at the joint. In addition, two types of materials having different hardnesses are mixed and extruded using two extruders, and the hardness is set along the axial direction by changing the ratio of each material while keeping the total amount extruded constant. There is also a method of continuously extruding with adjustment, but since the melting characteristics are different for each material, the diameter of the lumen varies greatly, and a multi-lumen catheter tube at a practical level has not been obtained. As described above, it has been difficult to obtain a high-quality multi-lumen catheter tube that can simultaneously satisfy the above characteristics.

An object of the present invention is to provide a high-quality flexible tube suitable as a multi-lumen catheter tube capable of simultaneously satisfying all of the characteristics of pushability, torque transmission, and followability.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the outer surface of an inner tube having a plurality of lumens was placed in the axial direction of the inner tube. By forming a reinforcing material layer that reinforces the inner pipe so that the bending stiffness changes substantially along the outer pipe outside the inner pipe with the reinforcing material layer interposed therebetween, the pushability and torque transmission property are improved. The present inventors have found that a flexible tube suitable as a multi-lumen catheter tube that can simultaneously satisfy all the characteristics of followability can be provided, and the present invention has been completed.

That is, the present invention is as follows. (1) A flexible inner tube having a plurality of lumens opened at both ends in the axial direction and not communicating with each other and having a substantially circular outer periphery, and one or more flexible inner tubes on the outer surface of the inner tube A reinforcing material in which the linear bodies are braided in a net shape and the angle formed by each linear body with respect to the axial direction of the inner pipe changes stepwise or continuously substantially along the axial direction. A reinforcing material layer interposed portion including a reinforcing material layer having a reinforcing member layer and a substantially cylindrical outer tube having flexibility and fixed to the outside of the inner tube via the reinforcing material layer. Sex tube. (2) The angle formed by each linear body with respect to the axial direction of the inner pipe is
The flexible tube according to the above (1), wherein the size of the flexible tube changes stepwise or continuously from one end to the other end. (3) The flexible tube according to the above (1) or (2), wherein the outer tube has a thickness of 1 μm to 200 μm. (4) The above (1), which is for a catheter.
The flexible tube according to any one of (1) to (3).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
FIG. 1 is a side view schematically showing a part of a reinforcing material layer intervening portion 2 of a flexible tube 1 according to a preferred embodiment of the present invention in a partially cutaway state, and FIG. 2 is an axial direction of an inner tube 3 of FIG. FIG. 3 is a simplified cross-sectional view taken along a cutting plane line II in an imaginary plane perpendicular to A, and FIG. 3 schematically shows a preferred example of a catheter 6 using the flexible tube 1 in FIG. FIG. As shown in FIGS. 1 and 2, the flexible tube 1 of the present invention has a reinforcing material layer having a flexible inner tube 3 and an outer tube 4 and a reinforcing material layer 5 interposed therebetween. An intervening part 2 is provided. The inner pipe 3 and the outer pipe 4 are fixed via the reinforcing material layer 5 between the outer surface of the inner pipe 3 and the inner surface of the outer pipe 4 so that the inner pipe 3 is located inside the outer pipe 4. You. In this specification, the “reinforcing material layer” refers to a portion containing a reinforcing material interposed between the inner pipe 3 and the outer pipe 4, and includes a reinforcing material and a layered adhesive containing the reinforcing material as described later. It may be formed, or may be formed only of a reinforcing material and not formed in a layered form. The flexible tube 1 of the present invention is particularly suitably used as a multi-lumen catheter tube in a catheter.

As shown in FIG. 3, the flexible tube 1 has a tip 7 connected to one end 2a of the interposed reinforcing material layer 2 in addition to the interposed reinforcing material layer 2 described above. The tip portion 7 is different from the reinforcing material layer interposition portion 2 in that the reinforcing material layer 5 is not interposed between the inner pipe 3 and the outer pipe 4. Connect the flexible tube 1 to the catheter 6
In such a case, a balloon 20 connected to at least one of the openings on the distal end portion 7 side of a plurality of lumens 10 to be described later is connected to the distal end portion 7 so as to be held substantially airtight from an external space. Is attached. Further, in this case, a plurality of hubs 8, for example, the same number of hubs 8 as the number of lumens 10 to be described later are mounted on the other end portion 2 b of the reinforcing material layer interposed portion 2 opposite to the one end portion 2 a.

The inner tube 3 has a plurality of lumens 10. The lumen 10 is connected to the flexible tube 1 without communicating with each other.
The inner tube 3 has openings at both ends in the axial direction of the inner tube 3, in other words, at the distal end portion 7 and the base end portion 9 of the tube 1, respectively. The shape of the lumen 10 is not particularly limited, but is preferably realized in a substantially cylindrical shape, and more preferably in a perfect circular cylindrical shape as shown in FIG.
Preferably, each lumen 10 has a longitudinal direction substantially parallel to each other, and more preferably each longitudinal direction is substantially parallel to the axial direction of the inner tube 3. Also, the number of the lumens 10 is not particularly limited, but is preferably two to six, more preferably three to five, and particularly preferably two types of lumens 10a and 10a having different diameters as shown in FIG. A total of four lumens 10 are formed for each two of 10b. The lumen 10
When the flexible tube of the present invention is used for a catheter, it serves as a flow path for a drug solution or a gas for balloon inflation. At the time of insertion into a blood vessel, a guide wire is inserted into the lumen 10. Of the two types of lumens, the larger-diameter lumen 10a is mainly used for, for example, injecting a drug solution or inserting a guide wire, and the smaller-diameter lumen 1a is used.
Ob is mainly used for gas injection for balloon inflation, for example. The two balloons 20 described above shown in FIG.
Are connected to the respective openings on the distal end portion 7 side of the two lumens 10b so as to be substantially airtightly held from the external space. In FIG. 3, four hubs 8 are mounted on the base end 9 side of the tube 1 in the same manner as the number of the lumens 10.
It functions as an inlet for a drug solution or gas into the inside of the tube 0 and an insertion opening for the guide wire, and also functions as a grip portion when operating the flexible tube 1.

The inner tube 3 has a plurality of lumens as described above, and is a tube member having a circular outer periphery. Preferably, the inner periphery of the inner tube 3 is realized in a perfect circular shape as shown in FIG. Is done. The material for forming the inner tube 3 is not particularly limited as long as it has a degree of flexibility and rigidity required when molded as a flexible tube. Preferred materials include, for example, Examples thereof include a polyethylene resin, a polyurethane resin, a polyvinyl chloride resin, a nylon resin, and a polypropylene resin. Among them, a polyethylene resin, particularly a high-density polyethylene resin is preferable.

The inner tube 3 has an outer diameter R1 of preferably 1.4 mm to 2.5 mm, and more preferably 1.7 mm.
mm to 2.3 mm. When the lumen 10 has, for example, two types of lumens 10a and 10b having different diameters from each other as described above, each of the lumens 10a and 10b is symmetric with respect to the axis of the inner pipe 3 as shown in FIG. Preferably, they are arranged so that In the case shown in FIG. 2, the diameter R2 of the larger lumen 10a is preferably 0.4 mm to
It is 1.2 mm, more preferably 0.6 mm to 1.0 mm, and the diameter R3 of the smaller lumen 10b is preferably 0.1 mm.
3 mm to 0.85 mm, more preferably 0.4 mm to
0.75 mm. Such an inner tube 3 preferably has a Shore D hardness of 40 to 80, more preferably 50 to 60.
Is realized as follows.

The outer tube 4 is realized by a substantially cylindrical tube member, preferably a perfect circular cylindrical tube member as shown in FIG. The material for forming the outer tube 4 is not particularly limited as long as it has a degree of flexibility and rigidity required when molded as a flexible tube. Polyurethane resin, parylene resin, nylon resin and the like can be mentioned. When using the flexible tube of the present invention for a catheter,
Among the above, a polyurethane resin having particularly excellent antithrombotic properties is preferred.

The outer diameter of such an outer tube 4 is preferably 1.6 mm to 2.7 mm, more preferably 1.9.
mm to 2.5 mm. The inner diameter R5 of the outer tube 4 is preferably substantially the same as the outer diameter R1 of the inner tube 3 described above. The outer tube 4 preferably has a thickness of 1 μm to 200 μm.
m, more preferably 10 μm to 100 μm. When the thickness of the outer tube is less than 1 μm, as shown in FIG. 2, it is realized by a configuration in which an adhesive is not interposed between the inner surface of the outer tube, the outer surface of the inner tube, and a linear body described later. In addition, the reinforcing material formed by braiding the linear body cannot be fixed on the outer surface of the inner tube, and the reinforcing material floats from the outer surface of the inner tube, and furthermore, the reinforcing material is caused by this floating. It is not preferable because there is a problem that a portion that shrinks occurs. Further, when the thickness of the outer tube exceeds 100 μm, when the inner tube has a suitable outer diameter, the outer diameter of the tube becomes too large, and the blood vessels that can be inserted when the tube is used as a multi-lumen catheter tube are limited. If the tube is to be realized or has a suitable outer diameter, it is necessary to make the outer diameter of the inner tube smaller, and as a result, the diameter of the lumen of the inner tube is limited. It is not preferable because there is a defect.

As a method for forming the outer tube 4 to a thickness of 1 μm to 200 μm, a coating application such as a dip coating or a spraying method may be mentioned, but the outer tube 4 has the above thickness and has a favorable interface with the reinforcing material layer. In order to obtain the outer tube 4 having adhesiveness, it is particularly preferable to form the outer tube 4 by dip coating. The outer pipe 4 preferably has a Shore D hardness of 40 to 80, more preferably 50 to 80.
70 is realized.

In the flexible tube 1 of the present invention, the angle formed with respect to the axial direction A of the inner tube 3 changes stepwise or continuously substantially along the axial direction A as described later. By braiding each linear body 11, the bending rigidity in the axial direction A is adjusted so as to change stepwise or continuously. Therefore, the change in the bending stiffness does not have to be adjusted by the difference in the stiffness of the constituent materials used for the inner tube 3 and the outer tube 4, and the inner tube 3 and the outer tube 4 may be made of the same material. When the inner tube 3 and the outer tube 4 are made of the same material, the manufacturing of the flexible tube 1 can be made easier and the manufacturing cost can be made lower.

Further, in the constituent material of the inner tube 3 and / or the outer tube 4, preferably in the constituent material of the outer tube 4, X
An X-ray contrast agent is kneaded so that the position of the flexible tube 1 can be confirmed under fluoroscopy. Examples of the X-ray contrast agent include metal powder of platinum, gold, silver, tungsten or an alloy thereof, barium sulfate, bismuth oxide, or a coupling compound thereof.

The diameters R1 to R5 of the inner pipe 3 and the outer pipe 4
May be constant along the axial direction A, respectively, or may vary within a preferred diameter range along the axial direction A. For example, as described later, when the flexible tube 1 of the present invention has a configuration in which the angle of the linear body 11 with respect to the axial direction A changes stepwise, before and after the angle of the linear body 11 changes. Also, before and after the boundary where the tip 7 and the reinforcing material layer interposed part 2 continue, the outer diameter R1 of the inner pipe 3 or the outer diameter R5 of the outer pipe 4 gradually decreases toward the tip 7 along the axial direction A. Alternatively, the diameters R2 and R3 of the lumens 10a and 10b may be similarly gradually increased toward the distal end portion 7.

The reinforcing material layer 5 interposed between the inner pipe 3 and the outer pipe 4 has a reinforcing material 12 in which a plurality of linear bodies 11 are braided in a net shape. As such a linear body 11, a round linear body having a substantially circular cross section perpendicular to its extending direction, a flat rectangular linear body having a substantially rectangular cross section, or the like is preferably used. Although not particularly limited, it is particularly preferable to use a rectangular linear body as shown in FIG. The material of such a linear body 11 is SUS
304, SUS316, SUS201, SUS303,
Examples thereof include stainless steel wires such as SUS305, SUS309, and SUS310, copper wires, nickel-titanium alloy wires, and aramid fibers. In particular, SUS304 is preferably used.

When the linear body 11 is realized as a rectangular linear body, a direction along a long side in the substantially rectangular shape of the cross section is defined as a width direction of the linear body 11, and a short direction substantially perpendicular to the long side is provided. The direction along the side is defined as the thickness direction of the linear body 11. The above-mentioned substantially rectangular shape includes a shape in which at least one of the long side and the short side is a curve, and also includes a substantially square shape. When the cross-sectional shape is substantially square, the direction along any one of the four sides is defined as the width direction, and the direction substantially perpendicular to the direction is defined as the thickness direction. When a rectangular linear body is used, it is braided so that its thickness direction substantially matches the radial direction of the inner tube 3. The size of the linear body 11 is not particularly limited as long as it is suitable for the braid, but the width is preferably 40 μm to 200 μm.
μm, more preferably 50 μm to 100 μm, and the thickness is preferably 5 μm to 50 μm, more preferably 20 μm to 40 μm.

When the linear body 11 is realized by a round linear body, it is preferable to use one having a cross-sectional area in the radial direction which is substantially equal to the cross-sectional area of the above-mentioned rectangular linear body. The diameter of such a round wire is preferably 30 μm to 60 μm.
m, more preferably 45 μm to 55 μm.

The linear body 11 is made of JIS G 4309.
Is preferably 500 MPa to 2000 MPa, more preferably 1 MPa.
000 MPa to 1500 MPa is used. If the tensile strength is less than 500 MPa, the linear body 11 is not easily cut during braiding, which is not preferable. On the other hand, when the tensile strength exceeds 2000 MPa, there is a problem that the braid is likely to be disturbed or sagged, which is not preferable.

The linear body 11 is braided in a net shape as shown in FIG. The term “net-like” as used in the present specification refers to a linear body braided by, for example, spirally winding a plurality of linear bodies 11 around the outer surface of the inner tube 3 without changing the winding direction and without sagging. 11 is a braided state in which they intersect with each other regularly. In the example shown in FIG. 1, the linear bodies 11 regularly intersect with each other, so that each linear body 1
The portions 13 which are so-called meshes surrounded by 1 have a rhombic shape, and are braided so that the area of the portion 13 is substantially uniform in, for example, each of the regions 14, 15, 16 described later. As long as the linear body 11 is braided in the mesh shape, the number used is not particularly limited, and may be one, or may be plural, but one linear body is particularly preferable. Braid using 11.

In the present invention, the reinforcing material is braided such that the angle formed by each linear body with respect to the axial direction of the inner pipe changes substantially along the axial direction. The change of the angle may be stepwise or continuous. FIG. 1 shows a case where the angle changes stepwise. When the angle formed by each linear body 11 with respect to the axial direction A of the inner pipe 3 changes stepwise, the reinforcing material layer intervening portion 2 is divided into a plurality of regions along the axial direction A. In FIG. 1, for example, the reinforcing material layer interposed portion 2 is connected to the flexible tube 1.
3 shows an embodiment in which the region is divided into three regions of a distal region 14, an intermediate region 15, and a proximal region 16 in order from the distal end portion 7 side to the proximal end portion 9 side.

In such a flexible tube 1, as shown in FIG. 1, the linear body 11 in the distal region 14 forms an angle θ 1 with respect to the axial direction A, and the linear body 11 in the intermediate region 15. Forms an angle θ2 with respect to the axial direction A, and the linear body 11 in the proximal end region 16 forms an angle θ with respect to the axial direction A.
3, the relationship of θ1>θ2> θ3 holds. The angle θ1 is preferably selected from the range of 50 ° to 90 °, more preferably 60 ° to 80 °.
Is preferably 35 ° to 65 °, more preferably 45 °
The angle θ3 is preferably selected from a range of 10 ° to 50 °, more preferably a range of 20 ° to 40 °.

In the reinforcing material layer 5, the smaller the angle of the linear body 11 is, the closer the extending direction of the braided linear body 11 becomes parallel to the axial direction A of the inner tube 3. The reinforcing effect of the reinforcing member 12 increases as the extending direction of the linear body 11 approaches parallel to the axial direction A, and the bending rigidity applied to the reinforcing member layer interposed portion 2 increases. Therefore, by setting the angle of the linear body 11 as described above, the bending rigidity of the intermediate region 15 becomes smaller than that of the base region 16, and the intermediate region 15 becomes smaller.
4 is smaller in bending rigidity than the intermediate region 15, and in the distal end portion 7 where the reinforcing material layer 5 does not exist, the distal side region 14
The bending stiffness becomes smaller than before. In other words, the flexible tube 1 is configured so that the flexibility gradually increases from the base end 9 toward the distal end 7.

In the case of such a structure, the reinforcing material layer interposed portion 2
When the bending stiffness in the distal region 14 is 1, the bending stiffness in the intermediate region 15 is preferably 1 to 3, more preferably 1.5 to 2.5.
The bending rigidity in the proximal region 16 is preferably 2 to
5, more preferably 3 to 4.

The length of the distal region 14, the intermediate region 15, and the proximal region 16 along the axial direction A is appropriately selected according to the application. For example, the total length of the catheter tube is 110 cm. When the length of the distal region 14 is 1 cm to 10 cm, the length of the intermediate region 15 is 10 cm to 40 cm, and the length of the proximal region 16 is 50 cm
~ 80 cm.

As described above, the flexible tube 1 of the present invention
Is configured such that the bending rigidity decreases from the base end 9 toward the distal end 7. As described above, the entire structure has moderate flexibility, and particularly has a high flexibility at the distal end portion 7 side. Therefore, when used for a catheter, the stimulation applied to the inner wall of the blood vessel and the like is extremely small, and the blood vessel moves ahead in the blood vessel. It is possible to provide the flexible tube 1 having excellent followability so as to be able to proceed smoothly without damaging the inner wall of the blood vessel along the guide wire.

Further, in the flexible tube 1, the pushing force of the operator in order to penetrate the blood vessel is surely applied from the proximal end 9 to the distal end 7 of the flexible tube 1 which is close to the operator. The flexible tube 1 has sufficient bending rigidity to transmit the rotation force applied at the proximal end portion 9 and reliably transmit the rotational force to the distal end portion 7. It is a highly rigid configuration. Therefore, it is possible to provide the flexible tube 1 that can exhibit excellent pushability and torque transmission.

In the flexible tube of the present invention,
Preferably, a linear body 11 having a tensile strength of 500 MPa to 2000 MPa is used. As described above, in the present invention, a material having an appropriate amount of moderate hardness and an appropriate amount of elongation is selected as the linear body 11, so that braiding is easier than braiding using a hard wire. For this reason, it is possible to provide a higher-quality flexible tube 1 having the reinforcing member 12 braided in a regular mesh without disturbing or sagging the linear body 11.

Further, in the present invention, preferably,
A rectangular wire is used as the wire 11. Such a rectangular linear body has an inner tube 3 having a circular cross section as compared with a case where the cross section is braided using a round linear body having a circular cross section.
There is an advantage that the linear body 11 can be stably held by the outer surface of the inner tube 3 at the time of braiding because the area in contact with the outer surface of the inner tube 3 is large. Therefore, the regular net-like reinforcing material 12 can be formed by an easier braid.

As described above, in the flexible tube 1 of the present invention, the braid can be surely braided according to a preset braid state. Therefore, buckling hardly occurs even if it is bent or bent at any portion, and buckling hardly occurs in the vicinity of the distal end portion 7 where buckling is likely to occur due to high flexibility compared to the base end side. In addition, the flexible tube 1 suitable for a catheter excellent in kink resistance, which does not easily buckle in a curved or bent portion of a blood vessel even after the guide wire is pulled out, can be provided.

The flexible tube using the rectangular linear body has a larger compressive strength in the radial direction than the flexible tube using a round wire having the same diameter as the thickness of the linear body 11, so that it is reinforced. The kink resistance can be improved without increasing the thickness of the material layer 5, which is particularly preferable.

The flexible tube of the present invention is preferably formed such that the outer tube 4 has a thickness of 1 μm to 200 μm. When the outer tube 4 is selected to have a thickness within the above range, the reinforcing material can be fixed on the inner tube, and a flexible tube having a lumen having a preferable diameter and having a finished outer diameter smaller than that of the conventional tube is provided. Can be formed. Therefore, when used as a multi-lumen catheter tube, a high-quality flexible tube that can be inserted into a blood vessel having a smaller diameter than before can be realized.

In the above embodiment, the distal end portion of the flexible tube has a structure in which no reinforcing material layer is interposed between the inner tube and the outer tube. However, in the present invention, the reinforcing material layer is also provided at the distal end portion. May be interposed. In such a case, the angle of the linear body 11 at the distal end portion with respect to the axial direction A is realized to be larger than the angle θ1 in the distal end region 14.

In the embodiment shown in FIG. 1, the reinforcing material layer interposed portion 2 is divided into three regions, that is, a distal region 14, an intermediate region 15, and a proximal region 16; It is not limited to division into regions, and the base end 9
If the configuration is such that the flexibility increases sequentially from the side toward the distal end portion 7 side, the configuration may be divided into two regions, or the configuration may be divided into four or more regions. You may.

Further, as described above, from the distal end portion 7 side to the proximal end portion 9
Although the configuration is such that the bending rigidity increases stepwise toward the side, the present invention is not limited to this, and
A configuration in which the bending rigidity continuously increases from the side toward the base end portion 9 may be employed.

In the flexible tube of the present invention, the bending stiffness basically increases stepwise or continuously from the distal end side to the proximal end side. For example, when the present invention is implemented to have a curved portion that bends in the intermediate region in advance, the bending rigidity in the intermediate region is larger than the bending rigidity in the proximal region. May be done.

Although the flexible tube 1 of the present invention is particularly suitable as a multi-lumen catheter tube in a catheter, its use is not limited to a catheter.

A preferred example of the method for manufacturing the flexible tube 1 of the present invention will be described. First, as is commonly done by those skilled in the art, for example, using a 30 mmφ extruder,
The inner tube 3 is extruded. The material described above is suitably used for the inner tube 3.

The linear body 11 is spirally wound around the outer surface of the formed inner tube 3. As the linear body 11, it is preferable to use a rectangular linear body having a tensile strength of 500 MPa to 2000 MPa as described above. The winding of the linear body 11 is suitably performed by a generally performed method using a braiding machine generally widely used in the art. As the braiding machine, a braiding machine may be used in which a rotating body attached with a linear body that rotates about the axis is rotated while the inner tube 3 is transported in a transport direction substantially along the axial direction. ,
Alternatively, a braid may be used in which the inner tube 3 itself is moved while being rotated about an axis and braided. For example, in the braiding machine having the above-described rotating body, the winding start position of the linear body 11 is set as a boundary between the distal end portion 7 and the distal end side region 14, and the rotation speed of the rotating body is kept constant and the inner tube 3 is transported along the transport direction. Braiding the linear body 11 so as to form the angles θ1, θ2, θ3 as described above by sequentially increasing the speed at each of the winding positions of the distal region 14, the intermediate region 15, and the proximal region 16. Can be. Thus, the reinforcing member 12 is formed.

Next, when manufacturing the flexible tube 1 having no reinforcing material layer 5 at the distal end as shown in FIG. 1, a wire braided at the distal end using an instrument such as a stripper, for example. Remove the body. Note that this step is not necessarily required in the production of the flexible tube 1 of the present invention, and this step must be performed when a flexible tube having a reinforcing material at the distal end as described above is desired. I just need.

The inner tube 3 obtained by winding the linear body 11 around the inner tube 3 is coated with the resin material forming the outer tube 4 so as to have a predetermined outer diameter R4. The coating is performed, for example, by dip coating using a dip coating device and then drying. For dip coating, for example, a solution using 7 wt% of DMF (N, N-dimethylformamide) as a solvent is preferably used. If the outer tube 4 is formed by extrusion in the manufacture of the flexible tube of the present invention, a problem occurs in that the lumen is crushed during the extrusion and the shape cannot be maintained. Therefore, in the present invention, the outer tube 4 is preferably formed by dip coating. The drying is preferably performed at a temperature of 40 ° C to 100 ° C, more preferably 50 ° C.
７０70 ° C. for 0.5 to 24 hours, more preferably 1 to 16 hours. Of these, drying at 60 ° C. for 3 hours is particularly preferred.

The coating is performed so that the inner surface of the outer tube 4 is fixed to the outer surface of the inner tube 3 via the linear body 11. Further, the fixing may be performed by interposing an adhesive such as a urethane adhesive or an epoxy adhesive between the inner surface of the outer tube 4 and the outer surface of the inner tube 3 and the linear body 11. In this manner, the reinforcing material layer 5 is formed so that the outer pipe 4 is located outside the inner pipe 3.
To form a flexible tube material fixedly attached thereto.

The X-ray contrast agent described above may be added to the material of the inner tube 3 and / or the outer tube 4 as described above. For example, bismuth oxide is added to the material of the outer tube 4 as the X-ray contrast agent. .

Finally, by cutting the above flexible tube material to a desired length, the flexible tube 1 of the present invention can be suitably obtained. The cutting of the flexible tube material is performed using an instrument such as a nipper.

The above is merely an example of a suitable manufacturing method, and the flexible tube 1 of the present invention does not have to be manufactured by the above manufacturing method.

[0050]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to the following examples. Example 1 A prototype of the flexible tube 1 having the configuration shown in FIGS. 1 and 2 was manufactured by the above-described manufacturing method. The conditions of each part of the tube 1 are as follows. In addition, the braid of the flat linear body 11 used the microminiature high-speed braid machine. Length of flexible tube 1: 110 cm Length of distal region 14: 10 cm Length of intermediate region 15: 20 cm Length of proximal region 16: 70 cm Length of distal end 7: 10 cm Outside diameter of inner tube 3 R1: 1.7 mm Inner diameter of lumen 10 a R2: 0.65 mm Inner diameter of lumen 10 b R3: 0.40 mm Thickness of outer tube 4: 40 μm Constituent material of inner tube 3: high-density polyethylene resin (Shore D)
Hardness: 65) Constituent material of outer tube 4: polyurethane resin (Shore D hardness:
60) Constituent material of rectangular wire 11: SUS304 Tensile strength of rectangular wire 11: 1420 MPa Width of rectangular wire 11: 89 μm Thickness of rectangular wire 11: 22 μm Angle θ1: 70 ° Angle θ2: 45 ° Angle θ3: 30 °

Example 2 A prototype of a flexible tube was produced in the same manner as in Example 1 except that the thickness of the outer tube was changed to 5 μm.

Example 3 A prototype of a flexible tube was produced in the same manner as in Example 1 except that the thickness of the outer tube was changed to 100 μm.

Comparative Example 1 A prototype of a flexible tube was produced in the same manner as in Example 1 except that the thickness of the outer tube was changed to 0.5 μm.

Comparative Example 2 A prototype of a flexible tube was produced in the same manner as in Example 1 except that the thickness of the outer tube was changed to 250 μm.

For each of the prototypes of Examples 1 to 3 and Comparative Examples 1 and 2, the braided reinforcing material was fixed on the outer surface of the inner tube 3 and had no floating or shrinkage. 、: When the fixing of the reinforcing material to the outer surface of the inner tube 3 was insufficient, and the floating or shrinkage was observed, it was evaluated as x.
Further, the outer diameter of the tube 1 was measured for each prototype, and those having an outer diameter of 2.1 mm or less were rated as ○, and those having an outer diameter exceeding 2.1 mm were rated as x. Table 1 shows the results.

Bending stiffness test A bending stiffness test was performed according to a test method specified in JIS K7203. The distal region and the proximal region of each prototype were cut to a length of 5 cm, respectively, and the load at the time of bending by 2 mm was measured by three-point bending, and this was defined as bending rigidity.
Regarding the tip side region of each prototype, when the bending stiffness is 0.3 N or less, the followability is sufficient, and when it exceeds 0.3 N, the followability is inferior. For the base end region of each prototype, if the bending stiffness is 0.6N or more, the pushability and torque transmission are considered to be sufficient. If it is less than 0.6N, the pushability and torque transmission are poor. Inferior was evaluated as x. The test was performed at a test speed of 1 mm / min, a distance between support points of 30 mm, and a test temperature of 23 ° C. Table 1 shows the results.

[0057]

[Table 1]

[0058]

As is clear from the above description, according to the present invention, a high-quality catheter suitable as a multi-lumen catheter tube capable of simultaneously satisfying all the properties of pushability, torque transmission and followability. A flexible tube can be provided.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a reinforcing material layer interposed portion 2 of a flexible tube 1 according to a preferred example of the present invention in a partially cut-out state.

FIG. 2 is a simplified cross-sectional view taken along a cutting plane line II in an imaginary plane perpendicular to the axial direction A of the inner tube 3 of FIG.

FIG. 3 is a catheter 6 using the flexible tube 1 of FIG.
It is a figure which shows one preferable example of.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible tube 2 Reinforcement material layer interposition part 3 Inner tube 4 Outer tube 5 Reinforcement material layer 6 Catheter 7 Tip 9 Base end 11 Linear body 12 Reinforcement 14 Tip side area 15 Intermediate area 16 Base side area

Claims (4)

[Claims] 1. A flexible inner tube having a plurality of lumens opened at both ends in the axial direction and not communicating with each other, and having a substantially circular outer periphery. Or a reinforcement in which a plurality of linear bodies are braided in a net-like manner, and an angle formed by each linear body with respect to the axial direction of the inner pipe changes stepwise or continuously substantially along the axial direction. A reinforcing material layer interposed portion including a reinforcing material layer having a material, and a substantially cylindrical outer tube having flexibility and fixed to the outside of the inner tube via the reinforcing material layer. Flexible tube. 2. The method according to claim 1, wherein the angle formed by each linear body with respect to the axial direction of the inner tube changes so as to increase stepwise or continuously from one end to the other end. The flexible tube according to claim 1. 3. The flexible tube according to claim 1, wherein the outer tube has a thickness of 1 μm to 200 μm. 4. The flexible tube according to claim 1, which is for a catheter.