JP2001079095A - Catheter tube and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel catheter tube excellent in operability and a new producing method capable of easily obtaining the catheter tube. SOLUTION: In a catheter tube 1 having a flexible insertion leading end part (a) integrally provided to the leading end of its tubular torque transmission part (b), a hardness change part b2 is provided to the torque transmission part (b) on the side of the insertion leading end part (a) thereof over constant length and the hardness of the hardness change part b2 lowers toward the insertion leading end part (a) continuously or multi-stepwise. By this constitution, since a place that suddenly changes in hardness is eliminating because the hardness of the leading end part of the torque transmission part (b) lowers continuously or multi-stepwise, operability is enhanced to a large extent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter tube used in a medical institution such as a hospital and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in a medical institution such as a hospital, a medical device such as a catheter tube is used for injecting a drug solution or a contrast medium into a predetermined site in a living body of a patient or for taking out a body fluid or the like in the living body. A tube-shaped medical device having flexibility is used.

[0003] Since this catheter tube is generally inserted into a living body using a thin blood vessel, urethra, or the like, it is possible to accurately insert the catheter tube without damaging a blood vessel wall, a living organ, or the like, particularly during insertion. There is a demand for high safety and operability such that the robot can reliably reach a predetermined location in a living body.

[0004] Therefore, the conventional catheter tube is
As shown in FIG. 11, an insertion tip a which is easy to bend without damaging blood vessels and living organs and has high elasticity;
And a torque transmitting portion b having a torque transmitting property for surely reaching the predetermined position.

[0005] As a conventional method for manufacturing a catheter tube having such a structure, for example, a braid made of a corrosion-resistant metal wire is firstly provided on the outer periphery of an inner tube made of a flexible plastic into which a round wire is inserted. After forming a reinforcing layer around the inner layer tube, the reinforcing layer located at the distal end of the inner tube, that is, the metal braid is removed by an electrochemical metal removing method to form a resilient distal end. Next, the outer periphery of the inner tube is covered with the same flexible plastic as the outer tube so as to cover the reinforcing layer, and the outer tube is integrally formed by extrusion so that the torque transmitting portion and the tip portion are alternately arranged. Thereafter, the tube body is cut so that the torque transmitting portion and the tip portion are paired, and then, after extending the round wire located at the shaft portion, the tube A method of forming is known by extracting from. In the figure, c is a connector connected to the rear end after the tube main body is manufactured.

[0006]

By the way, such a catheter tube has an insertion distal end portion a and a torque transmitting portion b.
Are formed integrally, there is no problem such as dropping of the insertion tip portion a into the living body, and the device has excellent reliability. However, there is a disadvantage that the operability is somewhat poor.

That is, since the hardness (rigidity) of this catheter tube is controlled by the presence or absence of a reinforcing layer in the inner tube, the catheter tube has an insertion tip a having no reinforcing layer and a reinforcing layer. With the torque transmitting portion b, the hardness is rapidly changed before and after the boundary. Therefore, when the operator is immature or the resistance at the time of insertion becomes large, the insertion end portion a is largely bent at the boundary with the torque transmission portion b, and a delicate insertion operation may not be performed. .

Accordingly, the present invention has been devised to effectively solve such a problem, and an object of the present invention is to provide a novel catheter tube excellent in operability and to easily obtain the catheter tube. It provides a new manufacturing method that can be performed.

[0009]

The low operability of the catheter tube as described above is largely attributable to the rapid change in the hardness between the insertion end portion a and the torque transmitting portion b. However, if the hardness of the torque transmitting portion is reduced according to the insertion distal end portion, the torque transmitting property is reduced. Conversely, if the hardness of the insertion distal portion is increased according to the torque transmitting portion, the inside of the living body at the time of insertion is reduced. There is a problem that it may be damaged.

Therefore, if the hardness of the tube is gradually reduced continuously or in multiple steps from the torque transmitting portion to the insertion tip, the operability of the entire tube can be improved without sacrificing the torque transmitting performance and flexibility. It is possible to greatly improve.

Therefore, first, it is conceivable to gradually lower the strength of the reinforcing layer which influences the hardness in the direction from the torque transmitting portion toward the insertion tip. As described above, this reinforcing layer is made up of more than ten metal layers. The wire is braided in a net-like manner over its length direction, and after being braided in units of several hundred meters together with the inner tube, it is cut to a length of about 2 to 3 m. Therefore, it is extremely difficult to change the strength of the reinforcing layer in the length direction along the length direction, in addition to the production technology, the cost is relatively high, and the productivity is remarkably increased. It gets worse.

Next, the reinforcing layer is omitted or its hardness is set low, and the outer layer tube is formed of a plurality of types of thermoplastic resins having only different hardnesses. It is conceivable to gradually lower the pressure continuously or in multiple steps from the portion to the insertion tip. However, conventionally, since the outer layer tube is formed by collective coating by extrusion, it is extremely difficult to supply and coat different resins with good timing to the coated portion, and the feasibility is poor.

Therefore, in order to solve the above-mentioned problem, the present invention provides a catheter tube having a flexible insertion tip integrally provided at the distal end of a tubular torque transmitting portion. Having a hardness changing portion over a certain length, and wherein the hardness of the hardness changing portion is reduced continuously or in multiple steps in the insertion tip side direction, Specifically, the hardness changing portion is formed of an inner tube and an outer tube covering the periphery thereof, and the outer tube is formed of a thermoplastic resin tape whose hardness changes continuously or in multiple steps in the length direction. The inner tube is spirally wound around the inner tube.

[0014] Thereby, the hardness of the catheter tube can be gradually reduced continuously or in multiple steps from the torque transmitting portion to the insertion distal end portion. It can be greatly improved.

The hardness change portion where the hardness changes gradually is formed by helically winding a thermoplastic resin tape whose hardness changes continuously or in multiple steps in the length direction. Its manufacture is relatively simple, and it is possible to divert existing equipment such as tape winding machines.
It is also economical.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a catheter tube 1 according to the present invention.
2 is a partially enlarged side view showing a portion A in FIG. 1, and FIGS. 3A and 3B are cross-sectional views taken along line AA in FIG. 2 and line BB, respectively. It is sectional drawing.

As shown in FIG. 1, the catheter tube 1 is provided with a flexible insertion tip a at the tip of a tube-shaped flexible torque transmitting portion b occupying most of the catheter tube. The connector has a connector c at its rear end, and its outer diameter and length are generally 0.5 mm to several mm and several tens cm to 3 m, respectively.

As shown in the figure, the torque transmitting portion b is divided into two zones, a high hardness portion b1 located on the connector c side and a hardness changing portion b2 located on the insertion tip end a side. In the high hardness portion b1, the hardness is uniform over the length direction, whereas in the hardness change portion b2, as shown in FIG. Over multiple levels.

The insertion tip a has a flexible structure in which the outer tube 3 is covered around the inner tube 2 as shown in FIG. On the other hand, as shown in FIG. 3B, a reinforcing layer 4 formed by braiding a plurality of corrosion-resistant metal wires such as SUS wires in an inner tube 2 constituting the torque transmitting portion b.
Are provided so as to exhibit the minimum torque transmission required for the torque transmission section b.

Therefore, in the catheter tube 1 of the present invention, the hardness changing portion b2, which constitutes the distal end portion of the torque transmitting portion b, is provided in multiple stages from the high hardness portion b1 to the insertion distal end portion a. Because there is no sharp change in hardness due to a decrease in the hardness, even if resistance is applied during insertion into a living body, the joint may be greatly bent at the boundary between the insertion distal end portion a and the torque transmitting portion b as in a conventional catheter tube. Is eliminated, so that excellent operability can be exhibited.

Next, a method of manufacturing the catheter tube 1 of the present invention having such a structure will be described with reference to FIGS.

First, as shown in FIGS. 4 (1) to 4 (3) and FIG. 5, a resin layer 2a serving as a raw material of an inner tube is placed on a round wire 5 made of metal wire or the like having a length of several hundred meters. After continuous application and baking in the longitudinal direction, a plurality of metal wires are similarly braided on the resin layer 2a in the longitudinal direction to form a reinforcing layer 4, and an inner layer is further formed thereon. The inner layer tube 2 having the reinforcing layer 4 inside is formed by applying and baking a resin layer 2b which is a raw material of the tube.

Next, as shown in FIG. 6, while the inner tube 2 thus formed is continuously fed out of the drum 6 together with the round wire 5, a resin having high hardness is applied onto the inner tube 2 by the extruder 7. After intermittently extruding and covering the entire lengthwise direction of the catheter tube, the inner tube 2 is cut at the boundary so that the coated portion and the uncoated portion are paired, and the catheter tube as shown in FIG. To form a tube to be a material of

Next, the reinforcing layer at the tip of the non-coated portion of the tube body is removed by an electrochemical metal removal method to form an insertion tip a having high elasticity. Then, as shown in FIG.
An outer tube 3 continuous with the resin of the coating portion by helically winding a thermoplastic resin tape T whose hardness has been changed continuously or in multiple stages in the length direction on the non-coating portion of the tube body.
To form a high hardness portion b1 and a hardness change portion b as described above.
2 to form a torque transmitting portion b divided into two zones. The thermoplastic resin tape is not particularly limited, but, for example, an existing resin such as a polyurethane resin, a polyamide resin, a polyethylene resin, a polyvinyl chloride resin, a fluororesin resin, or the like, If necessary, a contrast agent such as barium sulfate, bismuth oxide, or tungsten carbide, a stabilizer, an antioxidant, a coloring agent, or the like is added. Further, the reason why continuous thermoplastic resin tapes having different hardnesses are wrapped is that the lengths of portions having different hardnesses can be stably obtained by connecting tapes having different hardnesses in advance.

Next, since the outer tube including the hardness changing portion b2 formed in this manner often has minute irregularities on the surface thereof, the outer tube further increases the hardness as shown in FIG. Is inserted into the heat-shrinkable tube 8, heat-shrinked to press the surface of the outer tube 3 flush, and then the heat-shrinkable tube 8 is removed. At this time, if a fluorine-based resin is used as the heat-shrinkable tube 8, the heat-shrinkable tube 8 is less likely to be fused to the outer layer tube 3, so that the removal operation can be easily performed. When inserting the heat-shrinkable tube 8 into the heat-shrinkable tube 8, it is important to insert the heat-shrinkable tube 8 while keeping the tube straight. That is, if the heat-shrinkable tube 8 is inserted in a bent state, the thickness of the heat-shrinkable tube 8 will be uneven when heated and shrunk, resulting in uneven thickness, making it impossible to perform uniform pressing.

Finally, as shown in FIG. 10, the roundness of the round wire 5 located at the center of the shaft is extended and extracted, so that the hardness of the torque transmitting portion b is multi-step or continuous as described above. Thus, it is possible to obtain a catheter tube of the present invention, which is excellent in operability and has a smooth surface and high quality.

[0028]

EXAMPLE 1 An aqueous dispersion type PTFE dispersion was repeatedly applied and baked on a silver-plated soft copper wire having an outer diameter of 0.6 φ to a thickness of 0.03 mm.
16 SUS strands (having one strand) are braided at a pitch of 2.5, and the same water-dispersed PTF
E-dispersion was applied and baked to produce an inner tube of 200 m. Next, the inner layer tube was extruded and coated with a polyamide resin (nylon 12) at intervals of 1000 mm at intervals of 2000 mm, and 3000 m including 1000 mm not coated with the polyamide resin.
m. After that, two types of polyamide elastomer tapes (PEBAX5533, PE
BAX3533, thickness 80 μm, width 5 mm), inserted into a FEP heat-shrink tape held in a straight line, and after heating and cooling, remove the FEP heat-shrink tape and remove silver-plated annealed copper wire. Thus, a catheter tube according to the present invention was formed.

When the hardness and appearance of the catheter tube thus obtained were examined, the hardness varied in multiple stages from the rear end to the front end, and the surface was smooth throughout. It was confirmed that high quality and excellent operability were obtained.

Example 2 Two types of polyamide elastomer tapes having different hardnesses, PEBAX7033 and PEB
Except for using AX4033 (thickness 50 μm, width 5 mm), a catheter tube according to the present invention was formed in the same manner as in Example 1 and the hardness and appearance were examined in the same manner as in Example 1. From the results, it was confirmed that the hardness varied in multiple stages from the top to the tip, and that the surface was smooth over the whole, and that high quality and excellent operability were obtained.

[0031]

In summary, according to the present invention, the hardness gradually decreases continuously or in multiple steps from the torque transmitting portion to the insertion tip portion, and there is no sharp change in hardness. Operability can be exhibited. In addition, since the tape is formed by spirally winding a thermoplastic resin tape that changes in hardness in multiple stages, it exhibits excellent effects such as being able to easily and inexpensively produce a catheter tube with excellent operability. be able to.

[Brief description of the drawings]

FIG. 1 is a side view showing one embodiment of a catheter tube according to the present invention.

FIG. 2 is a partially enlarged view showing a portion A in FIG.

FIG. 3A is a sectional view taken along line AA in FIG. (B)
FIG. 3 is a sectional view taken along line BB in FIG. 2.

FIG. 4 is a cross-sectional view showing an embodiment showing an initial step of the method for manufacturing a catheter tube according to the present invention.

FIG. 5 is a sectional view taken along line AA in FIG. 4 (3).

FIG. 6 is a conceptual diagram showing a state in which an outer layer resin is intermittently extruded and formed on an inner layer tube.

FIG. 7 is a side view showing the tube obtained in the step of FIG. 6;

8 is a side view showing a state in which a thermoplastic resin tape is coated on the tube obtained in the step of FIG. 6;

9 is a side view showing a state where the tube obtained in the step of FIG. 8 is inserted into a heat-shrinkable tube.

FIG. 10 is a side view showing a state where a round wire is extended and removed from the tube body after the step of FIG. 9;

FIG. 11 is a side view showing the structure of a conventional catheter tube.

[Explanation of symbols]

 Reference Signs List 1 catheter tube 2 inner layer tube 3 outer layer tube 4 reinforcing layer 8 heat shrinkable tube a insertion tip b torque transmitting part b1 high hardness part b2 hardness change part T thermoplastic resin tape

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Ito 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Factory, Hitachi Cable, Ltd. (72) Inventor Masao Shirachi 5 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Electric Wire Co., Ltd. Hidaka Factory (72) Inventor Kenji Asano 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture Power Systems Research Laboratory, Hitachi Cable, Ltd.

Claims (9)

[Claims] 1. A catheter tube in which a flexible insertion tip is integrally provided at the tip of a tubular torque transmission part, wherein a hardness changing part is provided over a predetermined length on the insertion tip side of the torque transmission part. And the hardness of the hardness changing portion is reduced continuously or in multiple steps in the insertion tip side direction. 2. A thermoplastic resin tape in which the hardness change portion comprises an inner layer tube and an outer layer tube surrounding the inner layer tube, and the outer layer tube changes its hardness continuously or in multiple steps in the length direction. 2. The catheter tube according to claim 1, wherein the catheter tube is spirally wound around the outside of the inner tube. 3. The catheter tube according to claim 2, wherein the thermoplastic resin tape is formed by joining a plurality of tapes having different hardnesses. 4. The catheter tube according to claim 2, wherein a reinforcing layer is provided inside or around the inner layer tube. 5. A method for producing a catheter tube, wherein an outer tube is provided on an inner tube, and the hardness of the outer tube is continuously or multi-stepwise changed in a longitudinal direction. After being formed over a certain distance, a thermoplastic resin tape whose hardness changes continuously or in multiple stages in the length direction is spirally wound on the inner tube to form the outer tube. A method for manufacturing a catheter tube, comprising: 6. A method for producing a catheter tube, wherein an outer tube is provided on an inner tube, and the hardness of the outer tube changes continuously or in multiple steps in the longitudinal direction. After forming over a certain distance, on the inner layer tube, a thermoplastic resin tape whose hardness changes continuously or in multiple stages in the longitudinal direction is spirally wound to form an outer layer tube, and then, A method for manufacturing a catheter tube, comprising inserting the outer layer tube into a heat-shrinkable tube and heating the same to press the surface of the outer layer tube flush, and then removing the heat-shrinkable tube. 7. The inner tube is coated with a resin on a round wire and baked, and a braided metal wire is formed on a portion other than a tip portion thereof to form a reinforcing layer. The method for producing a catheter tube according to claim 5, wherein the catheter tube is formed by applying and baking. 8. When the outer tube is inserted into the heat-shrinkable tube, the outer tube is inserted into the heat-shrinkable tube while holding the heat-shrinkable tube in a straight line. The method for producing a catheter tube according to item 1. 9. The method according to claim 6, wherein the heat-shrinkable tube is made of a fluororesin.