JPH0374587B2 - - Google Patents

Description

[Detailed description of the invention] Background of the invention Technical field The present invention relates to a catheter and a method for manufacturing the same.

Prior Art A catheter is guided by a guide wire or the like and inserted into a body cavity such as a blood vessel, and the direction of its tip is controlled so that it can reach a target site, making it possible to perform treatment or examination. .

Therefore, for this catheter, it is necessary to have a certain degree of hardness, that is, relatively small flexibility, in the main body, and a certain degree of flexibility, that is, relatively large flexibility, in the tip part. In some cases, it may be necessary to be able to easily plastically deform the material by bending it into a shape suitable for the purpose. In particular, catheters for the vascular system are inserted into blood vessels and pushed forward, so their tips must have relatively high flexibility so as not to damage the blood vessel walls, and their main bodies must be relatively flexible. The part must have relatively little flexibility in order to accurately transmit the pushing force to the tip. Furthermore, in order to ensure reliable catheter insertion, the tip can be easily plastically deformed by bending it depending on the purpose at the time, such as when the insertion site is different or the shape of the insertion site differs depending on the patient. It has to be possible.

FIG. 1 is a partially cutaway view showing a conventional catheter 1. As shown in FIG. The catheter 1 has a flexible inner tube section 2.
By interposing the wire layer 4 between the body portion 5 and the flexible outer tube portion 3, the main body portion 5 has relatively low flexibility.
is formed. Furthermore, this catheter 1
A relatively flexible tip portion 6 is connected to the end portion of the main body portion 5 from which the outer tube portion 3 is partially removed.

However, in the case of the catheter 1,
The connecting portion between the main body portion 5 and the distal end portion 6 has a step on the outer surface that comes into contact with the blood vessel wall, making it difficult to insert it smoothly into the blood vessel, etc., and causing damage to the blood vessel wall or the formation of blood clots. There is a risk that this may occur. Further, due to a poor connection between the main body portion 5 and the tip portion 6, there is a possibility that the two may come apart.

OBJECTS OF THE INVENTION An object of the present invention is to provide a catheter in which a main body portion and a distal end portion having different physical properties are integrally molded reliably and without forming a step on the outer surface between the two.

Furthermore, the present invention provides a manufacturing method that enables stable manufacture of a catheter in which a main body portion and a distal end portion having different physical properties are integrally molded without forming a step on the outer surface between the two. The purpose is to provide.

Structure of the Invention In order to achieve the above object, the present invention provides a catheter in which a main body portion made of materials having different physical properties and a distal end portion are integrally molded in the axial direction, and the catheter is provided with a reinforcing layer. A main body side inner tube 14,
a distal end inner tube 15 connected to the main body inner tube 14;
It has the same inner diameter as the main body side inner tube 14 and the distal inner tube 15, and the expanded inner diameter portion provided at the connecting end of the main body side inner tube 14 and the expanded inner diameter portion provided at the connecting end of the distal inner tube 15. It has a connecting tube that is attached and connects the two inner tubes 14 and 15 to each other, and an outer tube that continuously covers the entire body side inner tube 14 and tip side inner tube 15, and the body side inner tube. 14 and the outer surface of the distal inner tube 15 are substantially smoothly continuous.

Further, in the present invention, the distal end inner tube 15 is made of a softer material than the main body inner tube 14.

Further, in the present invention, the distal end inner tube 15 is made of a material that is more easily plastically deformed than the main body inner tube 14.

Further, in the present invention, the reinforcing layer has a mesh shape.

Moreover, the present invention also provides the outer diameter of the reinforcing layer and the distal inner tube 1.
The outer diameters of the holes 5 and 5 are substantially the same.

Further, in the present invention, the reinforcing layer is embedded in the outer peripheral portion of the main body side inner tube 14.

The present invention also provides a method for manufacturing a catheter in which a main body portion made of materials having different physical properties and a distal end portion are integrally molded in the axial direction. A step of applying a reinforcing layer to the tube 14, a step of molding the distal inner tube 15, and a step of forming the main body inner tube 14 and the distal inner tube 15.
The distal inner tube 15 is attached to the connecting tube having an inner diameter equivalent to that of
connecting the inner tubes 14 and 15 to each other by attaching the expanded inner diameter portion provided at the connecting end of the inner tube 14 and the expanded inner diameter portion provided at the connecting end of the inner tube 14 on the main body side coated with the reinforcing layer; , a step of continuously covering the entire body-side inner tube 14 and distal-side inner tube 15, which are connected to each other, with an outer tube; It is designed to be substantially smoothly continuous.

Further, in the present invention, the step of applying the reinforcing layer to the main body inner tube 14 includes inserting the main body inner tube 14 wrapped around the reinforcing layer into a heating die, and applying the reinforcing layer to the outer periphery of the main body inner tube 14. It was designed to be buried in the body.

Further, in the present invention, the step of connecting the distal inner tube 15 and the main body inner tube 14 coated with the reinforcing layer is performed by alternately connecting the distal inner tube 15 and the main inner tube 14. The main body side inner tube 14 and the distal end side inner tube 1 are connected alternately and continuously.
5 is continuously coated with the outer tube, and then cut at a position corresponding to an approximately intermediate portion of the inner tube 14 on the main body side and at a position corresponding to approximately the intermediate portion of the inner tube 15 on the distal end side.

DETAILED DESCRIPTION OF THE INVENTION FIG. 2 shows a catheter 1 according to an embodiment of the present invention.
It is a partially cutaway view showing 0. The catheter 10 is
A main body portion 11 made of materials having mutually different physical properties;
The tip portion 12 is integrally formed in the axial direction.
That is, this catheter 10 includes a main body inner tube 14 covered with a mesh-like reinforcing layer 13, a distal inner tube 15 connected to the main body inner tube 14,
It consists of an outer tube 16 that continuously covers the entirety of the inner tube 14 on the main body side and the inner tube 15 on the distal end side. Here, the cartel 10 connects the main body side inner tube 14 and the distal end side inner tube 15 via a synthetic resin or metal connecting tube 17 having an inner diameter equivalent to their inner diameters. That is, the catheter 10
By expanding the inner diameters of the main body inner tube 14 and the distal inner tube 15 at their connecting ends, and attaching the connecting tube 17 to the expanded inner diameter portion, the inner diameter of the main body inner tube 14 is expanded to the distal inner tube. This allows the inner surface of the tube 15 to be substantially smooth and continuous.

The main body inner tube 14 and the distal end inner tube 15 are made of materials with different physical properties. Specifically, when the distal inner tube 15 is more flexible than the main body inner tube 14, that is, it is easily elastically deformed, and when the distal inner tube 15 is made of a material that deforms plastically, The main body side inner tube 14 may be made of a material that is easily elastically deformed. For example, in the catheter 10, the main body inner tube 14 is made of polyamide elastomer, and the distal inner tube 15 is made of polyamide elastomer or polyolefin elastomer made flexible with a plasticizer such as paraoxybenzoic ethylhexyl (POBO). Thus, the flexibility of the main body portion 11 is reduced, and the tip portion 1 is
2 can be made more flexible. Other materials for the inner tube on the main body side include polyamide, polyurethane, polyvinyl chloride, polyethylene,
It is possible to use a polypropylene resin or the like, and correspondingly, it is possible to select and use a resin with appropriate physical properties from among the above-mentioned resins as the material for the inner tube on the distal end side. Furthermore, as seen in the example of the polyamide elastomer mentioned above, by using an appropriate amount of plasticizer for each resin, the physical properties of the tip side and the main body side may be made different. Among the different physical properties, the aforementioned polyamide elastomer is typical in terms of flexibility, but in terms of plastic deformability at the tip, it is preferable that the main body inner tube is made of polyamide elastomer and the tip inner tube is made of polyethylene. Further, it is preferable that an X-ray opaque substance (for example, barium sulfate, bismuth subcarbonate, etc.) be mixed into the material constituting the distal inner tube 15 of the catheter 10. Polyamide elastomer is considered as a material that can be mixed with a larger amount of X-ray opaque material. Also, catheter 1
The outer tube 16 of 0 is made of the same material as the main body side inner tube 14 or the distal inner tube 15, or a material having flexibility intermediate between the main body inner tube 14 and the distal inner tube 15. It is formed. In addition, the main body side inner pipe 1
4. It is preferable that the distal inner tube 15 and the outer tube 16 be formed of materials that are highly compatible with each other.
Specifically, it is preferable that all the materials are of the same type. Also,
If the compatibility is low, the inner tubes 14, 15 and the outer tube 16
A new adhesive layer that is compatible with both may be provided between them. Note that the catheter 10 has, for example, an inner diameter of the main body side inner tube 14 and the distal side inner tube 15.
0.5 to 2.0 mm, outer diameter of outer tube 16 to 1 to 3 mm, outer tube 1
6 wall thickness 0.05-0.25mm, overall wall thickness 0.25-0.5
mm.

In addition, the catheter 10 has a reinforcing layer 13 with a wire diameter
By using stainless steel wire or the like with a diameter of 0.03 to 0.10 mm, it is possible to improve the responsiveness of the tip portion 12 to the rotation of the main body portion 11. It is preferable that the reinforcing layer 13 is formed in a mesh shape. This is because the responsiveness to rotation is better.

In addition, the catheter 10 has the reinforcing layer 13 buried in the outer periphery of the inner tube 14 on the main body side, and the reinforcing layer 13
It is preferable that the outer diameter of the inner tube 3 and the outer diameter of the distal inner tube 15 are substantially equal to each other. As a result, in the catheter 10, the wall thickness of the outer tube 16 is approximately the same on the main body side and the distal end side, and it is possible to improve the moldability of the outer tube 16. Further, in the catheter 10, the molded state of the outer tube 16 is not affected by the unevenness of the reinforcing layer 13, and a smooth outer tube surface can be obtained with a thin wall thickness of the outer tube 16. It is possible to enlarge the inner diameters of the inner tubes 14 and 15 while keeping the outer diameters of the inner tubes 16 the same.

Note that the catheter 10 is put into use after a catheter hub is connected to the end of the main body 11 and the distal end 12 is given a necessary bent shape. Further, the catheter 10 can have anticoagulant properties by coating the outer tube 16 with an anticoagulant such as heparin, an antithrombotic material such as hydroxyethyl methacrylate styrene copolymer, and silicone oil. It is possible to obtain low friction properties by applying a lubricant such as.

According to the embodiment described above, it is possible to obtain a catheter 10 in which the main body portion 11 having relatively low flexibility and the distal end portion 12 having relatively high flexibility are integrally molded. Since the outer tube is continuously coated over the entirety of the outer tubes 14 and 15, which smoothly connect the outer surfaces of each other, there is no step on the outer surface of the connecting portion between the main body portion 11 and the distal end portion 12. It is possible to smoothly insert the tube into a blood vessel or the like without damaging the blood vessel wall or forming a thrombus, and there is no risk of separation between the main body portion 11 and the distal end portion 12. Further, according to another material combination of the first embodiment, the catheter 10 is formed by integrally molding the main body portion 11 and the distal end portion 12 that is relatively easily deformed plastically.
It becomes possible to obtain. Therefore, any complicated shape of the insertion site can be created on the spot without creating a step on the outer surface of the connecting part between the main body part 11 and the distal end part 12, and even in the case of deformed parts by individual patients, the shape can be changed on the spot according to the purpose. The distal end can be deformed by bending, etc., and this makes it possible to insert the catheter reliably without damaging the blood vessel wall or forming a blood clot, and also prevents separation between the main body part 11 and the distal end part 12. There is no possibility that this will occur.

Next, a method for manufacturing the catheter 10 will be described with reference to FIGS. 3 to 7.

First, the outer periphery of a malleable metal core 21 such as a silver wire or copper wire is continuously coated with a synthetic resin material such as the polyamide elastomer to form the main body inner tube 14. Next, as shown in FIG. 3, a reinforcing layer 13 made of stainless steel wire or the like is wrapped around the outer periphery of the inner tube 14 on the main body side in a mesh pattern, and then a heating die 2
The reinforcing layer 13 is wrapped around the reinforcing layer 13, and the reinforcing layer 13 is buried in the outer circumference of the inner tubing 14, as shown in FIG. Here, the inner diameter of the heating die 22 is the same as the outer diameter of the main body side inner tube 14.

Next, the main body side inner tube 14 covered with the reinforcing layer 13
is cut along with the core bar 21 to a length slightly longer than twice the length corresponding to the main body 11 of the catheter 10, so that the core bar 21 is exposed for several centimeters on both ends of the inner tube 14 on the main body side. Peel off. Next, the core metal 21
After applying tension to both ends of the core bar 21 to extend the entire length of the core bar 21 and reducing the outer diameter of the core bar 21, the core bar 21 is pulled out from the main body side inner tube 14.

Next, the distal end inner tube 15, which was extruded in a separate process, and the main body inner tube 14 are connected by heat fusion, etc., using the aforementioned connecting tube 17, as shown in FIG. Turn and connect. Here, the distal end inner tube 15 and the main body inner tube 14 are alternately and continuously connected.

Next, as shown in FIG. 6, an extrusion molding machine 23 is used to continuously coat the entire body-side inner tube 14 and stopper-side inner tube 15, which are alternately and continuously connected, with a synthetic resin. By passing through the cooling tank 24, the outer tube 16 is formed. Next, the catheter 10 consisting of the main body part 11 and the distal end part 12 is cut by the cutting machine 25 at a position corresponding to the approximate middle part of the main body side inner tube 14 and at a position corresponding to the approximate middle part of the distal end side inner tube 15. get.

Finally, as shown in FIG.
Predetermined processing such as processing of the tip, processing of side holes, and connection of the hub 18 is performed.

According to the method for manufacturing the catheter 10 described above, the main body portion 11 having relatively low flexibility and the distal end portion 12 having relatively high flexibility can be reliably formed without forming a step between the outer surfaces of the two. The integrally molded catheter 10 can be easily manufactured. Further, by using the heating die 22, it is possible to easily embed the reinforcing tank 13 in the outer circumference of the main body side inner tube 14. In addition, after the outer tube is continuously coated over the entirety of the main body inner tube 14 and the distal inner tube 15 which are connected in an alternating and continuous manner, By cutting the tube 15 at a position corresponding to approximately the middle portion, a plurality of catheters 1 are cut.
It becomes possible to continuously mold the outer tube 16 corresponding to 0, and it is possible to improve the productivity of the catheter 10.

Note that another method for manufacturing the catheter 10 will be described below.

That is, as shown in FIG. 3 above, the main body side inner tube 14 on which the reinforcing layer 13 is applied with the core bar 21 inserted is slightly longer than the length corresponding to the main body 11 of the catheter 10. Then, only a portion of the main body side inner tube 14 corresponding to the length of the tip portion 12 is peeled off from the core bar 21. Next, the distal end inner tube 15 extruded in a separate process is inserted into the outer periphery of the core bar 21 from which the main body inner tube 14 has been peeled off.
The main body side inner tube 14 and the distal end side inner tube 15 are connected by heat fusion or the like in a connection structure using the aforementioned connecting tube 17.

Next, the main body side inner tube 14 and the tip side inner tube 15, which are connected to each other at the outer periphery of the core bar 21 as described above, are inserted into a bath of synthetic resin in a thermally molten state, and the tank outlet is The outer tube 16 is formed while regulating the outer diameter of the synthetic resin coated on the outer periphery of both inner tubes 14 and 15 by a die attached to the inner tube.

Next, tension is applied to both ends of the core bar 21, and the core bar 21 is
After reducing the outer diameter of tube 1, core bar 21 is pulled out from inner tubes 14 and 15. Next, both inner tubes 14, 15 and outer tube 16 are cut to a predetermined size to obtain a catheter 10 consisting of a main body portion 11 and a distal end portion 12. lastly,
Predetermined processing such as tip processing, side hole processing, hub connection, etc., of the catheter 10 is performed.

Specific Effects of the Invention As described above, the present invention provides a catheter in which a main body portion made of materials having different physical properties and a distal end portion are integrally molded in the axial direction, and the main body is covered with a reinforcing layer. Side inner tube 14 and main body side inner tube 1
4 and the main body side inner tube 1.
4 and the distal inner tube 15, and the expanded inner diameter section provided at the connecting end of the main body inner tube 14 and the expanded inner diameter section provided at the connecting end of the distal inner tube 15 are attached. A connecting tube that connects both inner tubes 14 and 15 to each other, and a main body inner tube 14 and a distal inner tube 15.
and an outer tube continuously coated over the entire surface of the tube.
The outer surface of the main body side inner tube 14 and the outer surface of the distal end side inner tube 15 are substantially smoothly continuous. Therefore, it is possible to obtain a catheter in which a main body portion with relatively low flexibility and a distal end portion with relatively high flexibility are integrally molded without forming a step between the two. It becomes possible.

Furthermore, in the present invention, the distal end inner tube 15 is made of a material that is more flexible than the main body inner tube 14, thereby reducing the flexibility of the main body and reducing the flexibility of the distal end. It is possible to make it larger.

Further, in the present invention, the distal end inner tube 15 is made of a material that is more easily plastically deformed than the main body inner tube 14.

Further, in the present invention, by making the reinforcing layer have a mesh shape, it is possible to improve the responsiveness of the tip portion to rotation of the main body portion.

Further, in the present invention, the outer diameter of the reinforcing layer and the outer diameter of the distal inner tube 15 are substantially equal to each other, so that the wall thickness of the outer tube is approximately equal between the main body side and the distal side. It is possible to improve the moldability of the outer tube.

Further, in the present invention, the reinforcing layer is
By embedding it in the outer periphery of the outer tube, the molding condition of the outer tube is not affected by the unevenness of the reinforcing layer, and a smooth outer tube surface can be obtained with a thin outer tube wall. Furthermore, it is possible to enlarge the inner diameter of the inner tube while keeping the outer diameter of the outer tube the same.

The present invention also provides a method for manufacturing a catheter in which a main body portion made of materials having different physical properties and a distal end portion are integrally molded in the axial direction. A step of applying a reinforcing layer to the tube 14, a step of molding the distal inner tube 15, and a step of forming the main body inner tube 14 and the distal inner tube 15.
The distal inner tube 15 is attached to the connecting tube having an inner diameter equivalent to that of
connecting the inner tubes 14 and 15 to each other by attaching the expanded inner diameter portion provided at the connecting end of the inner tube 14 and the expanded inner diameter portion provided at the connecting end of the inner tube 14 on the main body side coated with the reinforcing layer; , a step of continuously covering the entire body-side inner tube 14 and distal-side inner tube 15, which are connected to each other, with an outer tube; are made to continue substantially smoothly. Therefore, it is easy to manufacture a catheter in which a main body portion with relatively low flexibility and a distal end portion with relatively high flexibility are integrally molded without forming a step between the two. becomes possible.

Further, in the present invention, the step of applying the reinforcing layer to the main body side inner tube 14 includes inserting the main body side inner tube 14 wrapped with the reinforcing layer into a heating die, and applying the reinforcing layer to the main body side inner tube 14. By embedding the reinforcing layer in the outer periphery, it becomes possible to easily embed the reinforcing layer in the outer periphery of the main body side inner tube.

Further, in the present invention, the step of connecting the distal end inner tube 15 and the main body inner tube 14 coated with the reinforcing layer is such that the distal inner tube 15 and the main body inner tube 14 are connected alternately. After the body-side inner tube 14 and the tip-side inner tube 15, which are connected alternately and continuously, are entirely coated with the outer tube, approximately the middle part of the body-side inner tube 14 is connected. By cutting at the corresponding position and at a position corresponding to the approximate middle part of the distal inner tube 15, it is possible to continuously mold outer tubes corresponding to a plurality of catheters, and it is possible to improve productivity of catheters. becomes.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway view showing a catheter according to a conventional example, Fig. 2 is a partially cutaway view showing a catheter according to an embodiment of the present invention, and Fig. 3 shows a reinforcing layer coated on the inner tube on the main body side. Fig. 4 is a cross-sectional view showing the state in which the reinforcing layer is applied to the inner tube on the main body side, and Fig. 5 is a side view partially broken away showing the process of FIG. 6 is a side view showing the state in which the catheter is continuously connected; FIG. 6 is a side view showing the process of covering the entire inner tube on the main body side and the inner tube on the distal end side with the outer tube; FIG. 7 is a side view showing the completed state of the catheter. It is. 10...Catheter, 11... Main body, 12...
...Tip portion, 13...Mesh-like reinforcement layer, 14...Inner tube on the main body side, 15...Inner tube on the tip side, 16...Outer tube,
22... Heating die, 23... Extrusion molding machine, 25
……Cutting machine.

Claims (1)

[Claims] 1. A main body made of materials having different physical properties;
In a catheter whose distal end portion is integrally formed in the axial direction, a main body side inner tube 14 covered with a reinforcing layer, a distal side inner tube 15 connected to the main body side inner tube 14, and a main body side inner tube 14 Tube 14 and distal inner tube 15
The enlarged inner diameter part provided at the connecting end of the main body side inner tube 14 and the enlarged inner diameter part provided at the connecting end of the distal end side inner tube 15 are attached to both inner tubes 1.
4 and 15, and an outer tube that continuously covers the entire body-side inner tube 14 and distal-side inner tube 15. A catheter characterized in that the outer surface of tube 15 is substantially smooth and continuous. 2. The catheter according to claim 1, wherein the distal end inner tube 15 is made of a softer material than the main body inner tube 14. 3. Claim 1 in which the distal end side inner tube 15 is made of a material that is more easily plastically deformed than the main body side inner tube 14.
Catheters described in section. 4. The catheter according to any one of claims 1 to 3, wherein the reinforcing layer is mesh-like. 5. Claims 1 to 4, wherein the outer diameter of the reinforcing layer and the outer diameter of the distal inner tube 15 are substantially equal to each other.
Catheter according to any of paragraphs. 6. The catheter according to any one of claims 1 to 5, wherein the reinforcing layer is embedded in the outer periphery of the inner tube 14 on the main body side. 7 A main body made of materials with different physical properties,
The method for manufacturing a catheter in which the distal end portion and the distal end portion are integrally molded in the axial direction includes a step of molding the main body inner tube 14, a step of applying a reinforcing layer to the main body inner tube 14, and a step of forming the distal inner tube 15. A connecting tube having the same inner diameter as the main body inner tube 14 and the distal inner tube 15 is coated with an expanded inner diameter portion provided at the connecting end of the distal inner tube 15 and a reinforcing layer. A step of attaching the expanded inner diameter portion provided at the connecting end of the main body side inner tube 14 and connecting both inner tubes 14 and 15 to each other, and a step of connecting the main body side inner tube 14 and the distal end side inner tube 15 to each other. The outer surface of the main body inner tube 14 and the distal inner tube 1 are continuously covered with the outer tube.
5. A method for manufacturing a catheter, characterized in that the outer surface of the catheter is substantially smooth and continuous. 8 The step of applying the reinforcing layer to the main body side inner tube 14 is
Main body side inner tube 1 with reinforcing layer wrapped around heating die
8. The method of manufacturing a catheter according to claim 7, wherein the reinforcing layer is embedded in the outer periphery of the inner tube 14 on the main body side. 9 The step of connecting the distal inner tube 15 and the main body inner tube 14 coated with the reinforcing layer is the step of connecting the distal inner tube 15
5 and the main body side inner tube 14 are connected alternately and continuously, and the outer tube is continuously connected to the whole of the main body side inner tube 14 and the distal end side inner tube 15 which are connected alternately and continuously. 9. The method of manufacturing a catheter according to claim 7 or 8, wherein after coating, the main body side inner tube 14 is cut at a position corresponding to an approximately intermediate portion and the distal side inner tube 15 is cut at a position corresponding to an approximately intermediate portion.