JP2001327603A - Method of manufacturing flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of satisfactorily manufacturing a high grade flexible tube satisfied with push-in, torque transfer and follow-up properties at the same time, without crushing the shape of lumina. SOLUTION: The method of manufacturing the flexible tube comprises, at least, (1) a core contained inner tube forming step of forming a core contained inner tube consisting of an inner tube having an approximately circular outer periphery and a plurality of cores arranged in the inner tube, passing between both ends in the axial direction without contacting one another, (2) a reinforcing material layer forming step of braiding one or more wire material to be meshed so that angles to the axial direction of the inner tube are changed stepwise or continuously along the axial direction to form a reinforcing layer on the outer surface of the core contained inner tube, (3) an outer tube forming step of forming an approximately cylindrical outer tube to be fixed to the outer surface of the core contained inner tube via the reinforcing material layer, and (4) a core pull-out step for pulling the cores out of the core contained inner tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing 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, there is a demand for a manufacturing method for obtaining a high-quality flexible tube that can simultaneously satisfy the above-described characteristics and is suitable as a multi-lumen catheter tube having a lumen shape.

SUMMARY OF THE INVENTION An object of the present invention is to produce a high-quality flexible tube capable of simultaneously satisfying all the characteristics of pushability, torque transmission and followability without crushing the shape of the lumen. To provide a manufacturing method capable of

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, a state in which a portion corresponding to a plurality of lumens is filled when a flexible tube is formed. A reinforcing material layer is formed on the outer surface of the inner pipe so as to reinforce the inner pipe so that the bending rigidity changes substantially along the axial direction of the inner pipe. By forming the outer tube, it is possible to provide a method for producing a flexible tube suitable as a multi-lumen catheter tube that simultaneously satisfies all of the properties of pushability, torque transmission, and followability, while maintaining the shape of the lumen. And completed the present invention.

That is, the present invention is as follows. A method for producing a flexible tube, comprising at least the following steps: A cored inner tube forming a cored inner tube comprising an inner tube having a substantially circular outer periphery and a plurality of core wires penetrating through both ends in the axial direction of the inner tube and arranged so as not to be in contact with each other. Forming one or more linear shapes on the outer surface of the cored inner tube such that the angle formed with respect to the axial direction of the inner tube changes stepwise or continuously substantially along the axial direction. A reinforcing material layer forming step of forming a reinforcing material layer by braiding the body in a net shape, an outer tube forming step of forming a substantially cylindrical outer tube fixed to the outer surface of the cored inner tube via the reinforcing material layer, A core wire drawing step of drawing a core wire from a cored inner tube.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a flexible tube according to the present invention will be described in detail. The method for producing a flexible tube according to the present invention includes at least a cored inner tube forming step, a reinforcing material layer forming step, an outer tube forming step, and a core wire drawing step.

In the cored inner tube forming step, first, a member formed by coating a plurality of cores with a material for forming an inner tube described later and forming the inner tube on the cored wire, in other words, a cored inner tube is formed. Form. The coating and molding are performed using, for example, a 30 mmφ extruder.

The cored inner tube has a plurality of core wires penetrating through both ends in the axial direction of the inner tube and arranged so as not to be in contact with each other, and a tube having a circular outer periphery, preferably having a perfect circular outer periphery. It is formed so as to consist of an inner tube which is a tube member. The material forming the inner tube is not particularly limited as long as it has a degree of flexibility and rigidity required when molded as a flexible tube, but a preferable material is, for example, polyethylene. Resin, polyurethane resin, polyvinyl chloride resin, nylon resin, polypropylene resin, etc., among which polyethylene resin,
Particularly, a high density polyethylene resin is preferable. The inner tube is formed so that the outer diameter is preferably 1.4 mm to 2.5 mm, more preferably 1.7 mm to 2.3 mm. The inner pipe preferably has a Shore D hardness of 40 to 8
0, more preferably 50-60.

The shape of the core wire contained in the cored inner tube is not particularly limited, but is preferably a substantially cylindrical shape, and more preferably a perfect circular cylindrical shape. Preferably, each of the core wires is substantially parallel in a longitudinal direction in a state of being a cored inner tube, and more preferably, each of the longitudinal directions is substantially parallel to an axial direction of the inner tube. Also, the number of core wires is not particularly limited, but preferably 2 to 6, more preferably 3 to 5, and particularly preferably 4 wires. Among them, in particular, a cored inner tube containing two core wires each having two different diameters and containing a total of four core wires is preferable. Since the diameter of each core wire substantially corresponds to the diameter of each lumen of a flexible tube obtained by the manufacturing method of the present invention as described below, it is appropriately selected according to the diameter of the lumen of the flexible tube to be manufactured. Although not particularly limited, when four cores are contained as described above, the diameter of the larger core is preferably 0.4 mm to 1.2 mm, more preferably 0.6 mm
~ 1.0mm, the diameter of the smaller core wire is preferably 0.3mm ~ 0.8mm, more preferably 0.4mm ~
0.7 mm. In such a case, it is preferable that the core wires are arranged such that the core wires having the same diameter are symmetric with respect to the axis of the inner tube.

As the core wire, for example, SUS wire, soft copper wire or the like is used, and SUS304 is particularly preferably used.

The core wire is preferably JIS G430
The one having a breaking elongation of 15% to 100%, more preferably 30% to 60%, measured by the measuring method specified in No. 9 is used. If the elongation at break is less than 15%, the core wire cannot be sufficiently stretched in the core wire drawing step described below, so that the core wire and the wall surface of the inner tube in contact with the core wire cannot be sufficiently peeled off, and the core wire is pulled out from the cored inner tube. It is difficult and not preferable. When the elongation at break exceeds 100%, the core wire is stretched by the tension acting on the core wire during extrusion molding for forming the cored inner tube, so that the diameter of the lumen of the obtained inner tube is kept constant. It is difficult and not preferable.

The core wire is preferably JIS G4
0.2 measured by the measurement method defined in 309
% Proof stress is 80 MPa to 400 MPa, more preferably 1 MPa
20 MPa to 300 MPa is used. 0.2 above
When the% proof stress is less than 80 MPa, the core wire is elongated by the tension acting on the core wire at the time of extrusion molding when forming the cored inner tube, so that the diameter of the lumen of the obtained inner tube is kept constant. Is difficult and not preferable. Also 0.2
If the% proof stress exceeds 400 MPa, the core wire cannot be sufficiently stretched in the core wire drawing step described below, so that the core wire and the wall surface of the inner tube in contact with the core wire cannot be sufficiently separated, and it is difficult to pull out the core wire from the cored inner tube. Is not preferred.

[0016] The core wire may be coated in advance with a plating layer or a resin layer. Examples of the metal for forming the plating layer include nickel, chromium, silver, tin, and gold. It is particularly preferable to use a nickel-plated soft copper wire as the core wire on which the plating layer is formed. Also, as a resin for forming the resin layer,
For example, fluorine resin, polyimide resin and the like,
Among them, it is particularly preferable to use a fluorine resin.

The formation of these plating layers or resin layers is as follows:
It can be suitably performed by a method generally performed by a person skilled in the art, such as an electrolytic plating method, a spray spraying method, or a dip coating method. By pre-coating the core wire with such a plating layer or resin layer,
It is possible to eliminate a problem that metal powder generated from the core wire adheres to a wall surface in contact with the lumen of the inner tube when the core wire described later is pulled out. The flexible tube obtained by the manufacturing method of the present invention is suitably used as a multi-lumen catheter tube for medical use as described later, and is a foreign substance to a human body on a wall surface in contact with a lumen of an inner tube. If the metal powder is adhered, for example, a thrombus may be formed and clog a blood vessel, which is not preferable. In order to solve such a problem, it is preferable to use a core wire previously covered with a plating layer or a resin layer.

In order to make it easy to pull out the core wire,
Silicone oil may be applied to the core wire in advance.
The cored inner tube is formed by bringing the core wire into close contact with the wall surface of the inner tube in contact with the core wire. Therefore, if the core wire is forcibly pulled out when the core wire is pulled out, residual stress may be generated in the obtained inner tube, and a problem such as shrinkage of the inner tube may occur. By forming the inner tube on the core wire to which silicone oil has been applied in advance, the silicone oil is interposed between the core wire and the inner tube, whereby the core wire can be more smoothly pulled out, and the above-mentioned problem is solved. be able to. As a method of applying silicone oil, for example, a method commonly used by those skilled in the art, such as passing a core wire through water containing fine particles of silicone oil and then drying, may be mentioned. Specific examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, amino-modified silicone oil, and fluorosilicone oil. Among others, physiologically because inert trace, for example, from the viewpoint that none close influence on the human body as long as the application of 0.1mg / m ² ~10mg / m ² about quantities, dimethyl silicone oil, methylphenyl Silicone oil,
It is preferred to use methyl hydrogen silicone oil.

In the subsequent reinforcing material layer forming step, a reinforcing material layer is formed by spirally winding a linear body around the outer surface of the cored inner tube formed as described above and braiding it in a net shape. As such a linear body, it is preferable to use a round linear body having a substantially circular cross section perpendicular to the extending direction thereof, or a rectangular linear body having a substantially rectangular cross section. Although not particularly limited, it is particularly preferable to use a rectangular linear body. SUS304, SUS306, SUS201, SUS
303, SUS305, SUS309, SUS310, etc., stainless steel wire, copper wire, nickel-titanium alloy wire,
Aramid fiber and the like can be mentioned, and it is particularly preferable to use SUS304.

When the linear body is implemented by a rectangular linear body, the direction along the long side in the substantially rectangular shape of the cross section is defined as the width direction of the linear body, and the short side substantially perpendicular to the long side. The direction along this is defined as the thickness direction of the linear body. The above substantially rectangular shape also includes those in which at least one of the long side and the short side is a curve,
It also has 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 wire is used, it is braided so that its thickness direction substantially matches the radial direction of the cored inner tube. The size of the linear body is not particularly limited as long as it is suitable for the braid, but the width is preferably 40 μm to 200 μm, more preferably 50 μm to 100 μm, and the thickness is preferably 5 μm to 50 μm. Preferably 20 μm to 4
0 μm.

When the linear body 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. As such a round linear body, one having a diameter of preferably 30 μm to 60 μm, more preferably 45 μm to 55 μm is used.

The linear body preferably has a tensile strength measured by a measuring method specified in JIS G 4309 of 500 MPa to 2000 MPa, more preferably 100 MPa.
A material having a pressure of 0 MPa to 1500 MPa is used. If the tensile strength is less than 500 MPa, the linear body is liable to be 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 is wound around the outer surface of the cored inner tube and braided in a net shape. In addition, "net-like" referred to in this specification
For example, a plurality of linear bodies are wound around the outer surface of the cored core inner tube in a spiral manner without sagging by changing the winding direction of the linear bodies so that the braided linear bodies intersect each other regularly. Refers to the braided state. The reinforcing material layer is braided such that, for example, the linear bodies intersect each other regularly, so that the so-called mesh-like portions surrounded by the linear bodies each have a rhombic shape. The number of wires used is not particularly limited as long as the wire is braided into the mesh shape, and may be a single wire or a plurality of wires, but particularly preferably one wire is used. Braiding using Such a braiding is suitably performed by a generally performed method using a braiding machine generally widely used in the art. As the braiding machine, a machine that performs braiding by rotating a rotating body to which a linear body is attached around the axis while transporting the cored inner tube in a transport direction substantially along the axial direction may be used. Alternatively, a braid may be used in which the cored inner tube itself is moved while rotating about the axis.

As described above, in the present invention, braiding is performed on the cored inner tube. By performing braiding in a state in which the inner tube includes the core wire, unlike the case where braiding is performed on the inner tube having a hollow lumen, the problem that the lumen is collapsed during braiding is ensured. Can be eliminated.

In the present invention, the reinforcing members are braided in a net-like manner such that the angle formed by each linear member 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. When it is desired to obtain a flexible tube having a configuration in which the angle changes stepwise in a plurality of regions as described later, for example, in a braiding machine having the rotating body, the rotational speed of the rotating body is fixed, and The linear body can be braided such that the angle changes stepwise for each region by sequentially increasing the speed of conveyance along the conveyance direction at each winding position of each region.

In the case of manufacturing a flexible tube having no reinforcing material layer at the tip, after braiding such a linear body,
For example, the linear body braided at the distal end portion is removed using an instrument such as a stripper. In the production of the flexible tube of the present invention, the removal of this linear body is not always necessary, and if it is desired to obtain a flexible tube having a reinforcing material also at the tip end, this removal must be performed. Good.

In the subsequent outer tube forming step, the cored inner tube obtained in the above-described reinforcing material layer forming step and the linear body wound thereon are formed into a predetermined outer diameter with a material for forming an outer tube described later. Cover. The coating method is not particularly limited, and examples thereof include a method of dip coating using a dip coating device and drying. For dip coating, for example, a solution using 7 wt% of DMF (N, N-dimethylformamide) as a solvent is preferably used.
Drying is preferably performed at a temperature of 40 ° C to 100 ° C, more preferably 50 ° C to 70 ° C, for a time of 0.5 hour to 2 hours.
The reaction is performed for 4 hours, more preferably 1 hour to 16 hours. Of these, drying at 60 ° C. for 3 hours is particularly preferred. In the production method of the present invention, the outer tube may be formed by extrusion. When the outer tube is formed by extrusion molding, for example, a device such as a 30 mmφ extruder is suitably used.

The coating is made so that the inner surface of the outer tube is fixed to the outer surface of the cored inner tube with the linear body interposed therebetween.
Further, the fixing may be performed by interposing an adhesive such as a urethane-based adhesive or an epoxy-based adhesive between the inner surface of the outer tube and the outer surface and the linear body of the cored inner tube. In this way, a cored wire flexible tube material which is fixed via the reinforcing material layer so that the outer tube is outside the cored inner tube is formed.

The outer tube is formed into a substantially cylindrical tube member, preferably a perfect circular cylindrical tube member. The material for forming the outer tube is not particularly limited as long as it has a degree of flexibility and rigidity required when molded as a flexible tube, but a preferable material is, for example, polyurethane. Resins, parylene resins, nylon resins and the like are listed, and among them, polyurethane resins having excellent antithrombotic properties are preferable. Such an outer tube is formed so that its outer diameter is preferably 1.6 mm to 2.7 mm, more preferably 1.9 mm to 2.5 mm. The material of the outer tube preferably has a Shore D hardness of 40 to 40.
80, more preferably 50-70.

An X-ray contrast agent is contained in the constituent material of the inner tube and / or the outer tube, preferably in the constituent material of the outer tube, so that the position of the flexible tube can be confirmed under fluoroscopy during use. Kneaded. 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 of the inner tube and the outer tube may be constant along the axial direction of the tube material, or may be changed within the range of each suitable diameter along the axial direction. Is also good. For example, as described later, when the flexible tube manufactured by the manufacturing method of the present invention has a configuration in which the angle of the linear body with respect to the axial direction changes stepwise, the angle of the linear body changes. Before and after, and before and after the boundary where the distal end portion and the reinforcing material layer intervening portion continue, the outer diameter of the inner pipe or the outer diameter of the outer pipe gradually decreases toward the distal end along the axial direction, or Similarly, the inner diameter may be formed so as to gradually increase toward the tip.

In the final core wire drawing step, the core-containing flexible tube material is first cut to a desired length.
The cutting of the flexible tube material is performed using an instrument such as a nipper. After cutting, the core wire is pulled out, and the flexible tube of the present invention can be suitably obtained. The drawing of the core wire is performed, for example, by using a device such as a core wire drawing machine to extend the core wire to reduce the diameter of the core wire, and to peel off each core wire from each inner surface of the inner tube.

FIGS. 1 and 2 show preferred examples of the flexible tube manufactured by the manufacturing method of the present invention.
FIG. 3 shows a preferred example of a catheter using the flexible tube.
Shown in FIG. 1 is a side view schematically showing a part of a reinforcing material layer interposed portion 2 of a preferred example of a flexible tube 1 obtained by a manufacturing method of the present invention in a partially cut-out state, and FIG. FIG. 4 is a simplified cross-sectional view taken along a cutting plane line II in a virtual plane perpendicular to the axial direction A of the inner tube 3,
FIG. 3 is a simplified diagram showing a preferred example of a catheter 6 using the flexible tube 1 of FIG. As shown in FIGS. 1 and 2, the flexible tube 1 obtained by the present invention has an inner tube 3 and an outer tube 4 having flexibility and a reinforcing material layer 5 interposed therebetween. Reinforcement layer interposed 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 as described above. It may be formed, or as shown in FIGS. 1 and 2, may be formed only of the reinforcing material and not formed in a layered form.

As shown in FIG. 3, the flexible tube 1 is provided with 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.
Of the inner tube 3, in other words, the distal end 7 and the proximal end 9 of the tube 1 have openings 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. When the flexible tube of the present invention is used for a catheter, the lumen 10 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 10b is
For example, it is mainly used for gas injection for balloon inflation. The above-mentioned two balloons 20 shown in FIG. 3 are attached to, for example, the respective openings of the two lumens 10b on the distal end portion 7 side so as to be kept substantially airtight from an external space. In FIG. 3, four hubs 8 are mounted on the base end portion 9 side of the tube 1 in the same manner as the number of the lumens 10. The hub 8 is an inlet for a drug solution or gas into the lumen 10 and an insertion port for the guide wire. , And also functions as a grip when operating the flexible tube 1.

In the flexible tube obtained by the production method of the present invention, the angle formed with respect to the axial direction of the inner tube changes stepwise or continuously substantially along the axial direction as described above. By braiding each linear body as described above, the bending rigidity in the axial direction 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.

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. FIG. 1 shows a case where the angle changes stepwise. Axial direction A of inner tube 3
When the angle formed by each linear body 11 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 shown 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 of the flexible tube 1.

In such a flexible tube 1, as shown in FIG. 1, the linear member 11 in the distal region 14 forms an angle θ 1 with respect to the axial direction A, and the linear member 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 to be parallel to the axial direction A of the flexible tube 1. The reinforcing effect of the reinforcing member 12 increases as the extending direction of the linear member 11 approaches parallel to the axial direction A of the inner tube 3, 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 is smaller than that of the proximal region 16, the bending rigidity of the distal region 14 is smaller than that of the intermediate region 15, and the distal region 7 where the reinforcing material layer 5 does not exist is the distal 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 flexible tube 1 is reduced. When the height is 110 cm, the tip side region 1
4 is 1 cm to 10 cm in length, and the length of the intermediate region 15 is 1 cm.
0 cm to 40 cm, the length of the proximal region 16 is 50 cm to
80 cm.

As described above, the flexible tube 1 obtained by the manufacturing method 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 a moderate flexibility, and particularly has a high flexibility at the distal end portion 7 side, so that the stimulation applied to the inner wall of the blood vessel and the like is extremely small, and the inner wall of the blood vessel is guided along the preceding guide wire in the blood vessel. Flexible tube 1 with excellent followability so that it can proceed smoothly without damaging
Can be provided.

Further, in the flexible tube 1, the pushing force of the surgeon in order to penetrate the blood vessel is reliably transmitted from the proximal end 9 to the distal end 7 of the flexible tube 1 which is close to the surgeon. In addition, the flexible tube 1 has sufficient rigidity so that the rotational force applied at the proximal end 9 can be reliably transmitted to the distal end 7, and the rigidity is particularly high at the proximal end 9 side. It is. Therefore, it is possible to provide the flexible tube 1 that can exhibit excellent pushability and torque transmission.

Further, in the flexible tube 1 manufactured by the manufacturing method of the present invention, a flat linear body as shown in FIG. 2 is preferably used as the linear body 11. Since the flat linear body has a larger compressive strength in the radial direction than a flexible tube using a round wire having the same diameter as the thickness thereof, the kink resistance can be improved without increasing the thickness of the reinforcing material layer 5. Can be improved.

As described above, in the present invention, in the step of forming the reinforcing material layer, the linear body is braided with respect to the cored inner tube, which is compared with the case of the inner tube having a hollow lumen. Therefore, the inner tube is not collapsed by the braid, the shape of the lumen is securely held, and all of the above-mentioned characteristics are satisfied, and the shape of the lumen 10 is maintained, which is an extremely practical and high-grade flexible material. The tube 1 can be obtained.

In the above embodiment, the distal end portion 17 of the flexible tube 1 has a structure in which the reinforcing material layer 5 is not interposed between the inner tube 3 and the outer tube 4, but according to the manufacturing method of the present invention. The obtained flexible tube may have a reinforcing material layer interposed also at the distal end. In such a case, the angle of the linear body at the distal end portion with respect to the axial direction is realized to be larger than the angle at the distal end side region.

Further, 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, it may be manufactured into a configuration divided into two regions, or into a configuration divided into four or more regions. It may be manufactured.

Also, as described above, from the distal end portion 7 side to the proximal end portion 9 side.
Although the configuration is such that the rigidity increases stepwise toward the side, the flexible tube obtained by the present invention is not limited to this, and the flexible tube is continuous from the distal end 7 side to the proximal end 9 side. The configuration may be such that the rigidity increases.

The flexible tube obtained by the manufacturing method of the present invention has a structure in which the rigidity basically increases stepwise or continuously from the distal end side to the proximal end side. However, this need not be the case, for example, if the invention is to be realized with a flexible tube with a bend that is pre-curved in the intermediate region, the rigidity in the intermediate region is greater than the rigidity in the proximal region. It may be formed to be large.

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

[0051]

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 linear body 1
An ultra-small high-speed braiding machine was used for braiding the rectangular linear body used as 1. 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 1.7 mm Inner diameter of lumen 10 a: 0.65 mm Inner diameter of lumen 10 b: 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: SUS304 Tensile strength of rectangular wire: 1420 MPa Width of rectangular wire: 89 μm Thickness of rectangular wire: 22 μm Angle θ1: 70 ° Angle θ2: 45 ° Angle θ3: 30 ° core wire: SUS304 (elongation at break: 56%, 0.2% proof stress: 281 MPa)

Comparative Example 1 A prototype of a flexible tube was produced in the same manner as in Example 1 except that the core wire was not used.

With respect to each of the prototypes of Example 1 and Comparative Example 1, the case where the lumen was not crushed was evaluated as ○, and the case where the lumen was crushed was evaluated as ×. Table 1 shows the results.

Bending stiffness test For each prototype of Example 1 and Comparative Example 1, JI
A test of flexural rigidity was performed by a test method specified in SK7203. Cut the distal region and the proximal region of each prototype to a length of 5 cm, respectively, and perform 2-point bending by 2 m.
The load at the time of m bending was measured, and this was defined as bending rigidity. Judgment of the followability is as follows: when the flexural rigidity is 0.3 N or less in the tip side region of each prototype, it is determined that the followability is sufficient,
When it exceeded 0.3 N, it was evaluated as poor because of poor followability. The indentation and torque transmission were judged as follows: when the bending stiffness of the base end region of each prototype is 0.6 N or more, the indentation and torque transmission are considered to be sufficient. Indicates that the indentability and the torque transmission were inferior. 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.

[0055]

[Table 1]

[0056]

As is apparent from the above description, according to the present invention, a high-quality flexible tube capable of simultaneously satisfying all of the characteristics of pushability, torque transmission, and followability is provided in a lumen. It is possible to provide a manufacturing method that can be suitably manufactured without crushing the shape.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a preferred example of a flexible tube 1 manufactured by a manufacturing method of the present invention in a state in which a reinforcing material layer interposition part 2 is partially cut away.

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

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Utsumi 4-3 Ikejiri, Itami-shi, Hyogo F-term (reference) 4C061 DD03 FF24 JJ06 in Itami Works, Mitsubishi Cable Industries, Ltd.

Claims (1)

[Claims] 1. A method for producing a flexible tube, comprising at least the following steps: A cored inner tube forming a cored inner tube comprising an inner tube having a substantially circular outer periphery and a plurality of core wires penetrating through both ends in the axial direction of the inner tube and arranged so as not to be in contact with each other. Forming one or more linear shapes on the outer surface of the cored inner tube such that the angle formed with respect to the axial direction of the inner tube changes stepwise or continuously substantially along the axial direction. A reinforcing material layer forming step of forming a reinforcing material layer by braiding the body in a net shape, an outer tube forming step of forming a substantially cylindrical outer tube fixed to the outer surface of the cored inner tube via the reinforcing material layer, A core wire drawing step of drawing a core wire from a cored inner tube.