JPH11114068A - Medical tube and medical tube producing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical tube provided with a tip flexibility together with a pushability, a trackability, torque transmitting property and kink proof property. SOLUTION: The medical tube 1 is formed by a flexible first resin 11 and the second one 12 with a rigidity being higher than that of the first one 11. The medical tube 1 is provided with a flexible tip side part 2 formed only by the first resin 11, a base end side part 3 with a high regidity, which is formed only by the second resin 12, and an intermediate part 4 formed between the tip side part 2 and the base end side part 3. The intermediate part 4 is in a state where the first resin 11 and the second resin 12 are continuously and also spirally wound in a belt-shape mutually and also the width of the belt of the second resin 12 is gradually narrowed toward the tip side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a medical tube used for a vascular catheter, an ultrasonic catheter, an endoscope and the like.

[0002]

2. Description of the Related Art In recent years, medical tubes have become highly functional. Highly functional medical tubes are used, for example, for vascular dilatation balloon catheters used in percutaneous angioplasty to dilate stenosis in blood vessels, aneurysms and arteriovenous malformations found in cerebral blood vessels, etc. In contrast, a cerebral vascular catheter that injects embolic substances and coils, an ultrasonic catheter that enables precise observation and diagnosis of blood vessels using an ultrasonic diagnostic device, and an intravascular, bile duct, pancreatic duct, etc. that uses an image diagnostic device It is used for endoscopes and the like that can perform various observations and diagnoses.

[0003] Such a high-performance medical tube is required to be operable and durable so that it can be quickly and reliably inserted into a thin and complicated blood vessel. Specifically, the operator easily pushes the catheter in order to penetrate the blood vessel (pushability), and proceeds smoothly in a complicated meandering blood vessel along a guide wire inserted in advance without damaging the blood vessel inner wall. That (trackability), that the rotational force transmitted at the proximal end of the catheter tube is reliably transmitted to the distal end (torque transmission), at the time of preoperative handling and when pushing the catheter, and
In order to reduce the size of the guiding catheter that guides the catheter to the target site in order to reduce the physical and mental burden on the patient, to reduce the size of the guiding catheter, The outer diameter of the tube should be as thin as possible (low profile) to reduce frictional resistance with the tube, and the tube lumen should be sufficiently secured (thin wall) to improve the operability of the guidewire. It is required that the distal portion does not damage the blood vessel wall or the like (flexibility at the distal end).

Further, in an ultrasonic catheter, a fixed housing of an ultrasonic vibrator which rotates in the circumferential direction about the central axis of the tube lumen comes into contact with the inner wall of the tube, causing uneven rotation.
In order to prevent the tube from being damaged, it is required that the tube be hardened at a few millimeters where the ultrasonic vibrator rotates.

As described above, high-performance medical tubing is required to have not only thinness and torque transmitting properties but also contradictory properties such as hardness and softness, thinness and difficulty in breaking. It is also required that the tube be partially stiff. In order to manufacture a catheter tube that satisfies these required characteristics, various technical developments have conventionally been made. As a method for manufacturing the catheter tube itself, a method of molding with an extruder is generally used. As a method of imparting such properties to the molded catheter tube, a method of imparting at the time of tube extrusion molding, a method of processing and imparting the molded tube, and partially modifying the physical properties of the molded tube There is a method of applying, a method of applying another material to the formed tube in combination, or a method of applying these in combination.

For example, there is one disclosed in Japanese Patent Application Laid-Open No. 7-232368. The device disclosed therein,
It comprises two extruders and a plurality of branch lines so that material streams of different components are distributed in the circumferential direction of the tubular molding. The different materials are combined in alternating strips with the walls of the extrudate, and the material streams conveyed through the branch line flow together in the forming nozzle. The forming nozzle is provided with a rotating part, can rotate in a circumferential direction, and can form a material body extending in a spiral pattern, and a medical tube formed thereby is disclosed.

[0007]

The medical tubing disclosed in the above-mentioned publication has a strip shape and a spiral shape made of two kinds of different materials. Is used, as a medical tube, there is little change in physical properties at the distal end and the proximal end,
It has been difficult to provide a plurality of requirements as a medical tube as described above, in particular, pushability, trackability, torque transmission, and kink resistance, as well as tip flexibility.

A first object of the present invention is to provide a medical tube having flexibility at the tip as well as pushability, trackability, torque transmission and kink resistance. A second object of the present invention is to provide pushability,
An object of the present invention is to provide a medical tube having a trackability, a torque transmission property, a kink resistance, a tip flexibility, a reinforcement portion at a tip portion, and an effective ultrasound catheter tube. A third object of the present invention is to
An object of the present invention is to provide a medical tube manufacturing apparatus capable of manufacturing the above-described medical tube continuously and integrally.

[0009]

What achieves the first object is a medical tube formed of a flexible first resin and a second resin having a higher rigidity than the first resin. The medical tube has a flexible distal portion formed only of the first resin, a highly rigid proximal portion formed only of the second resin, and a distal portion. An intermediate portion formed between the base end portions, wherein the intermediate portion has a state in which the first resin and the second resin are continuously wound alternately in a strip shape and a spiral shape. The width of the band of the second resin is a medical tube that gradually narrows toward the distal end. It is preferable that the width of the first resin is gradually reduced toward the base end.

What achieves the second object is a medical tube formed of a flexible first resin and a second resin having higher rigidity than the first resin. The tube has a flexible distal portion formed only of the first resin, a highly rigid proximal portion formed only of the second resin, and a tube between the flexible distal portion and the proximal portion. And a formed intermediate portion, wherein the intermediate portion is located on the base end side, and the first resin and the second resin are continuously and alternately wound in a band shape and a spiral shape. And the width of the band of the second resin, the first spiral portion formed so as to gradually narrow toward the distal end, and located at the distal end side from the first spiral portion,
The first resin and the second resin are continuously and alternately wound in a band shape and a spiral shape, and the width of the band of the second resin gradually increases toward the front end side and the rear end side. 10 is a medical tube including a second spiral portion formed to be narrow.

[0011] In each of the above medical tubes, the first resin and the second resin are preferably a combination of resins having high compatibility. Further, it is preferable that the thickness of the medical tube is substantially uniform.

Further, the above-mentioned third object is achieved by:
A crosshead, a first resin extruder that supplies a first resin to the crosshead, a second resin extruder that supplies a second resin to the crosshead, the first resin extruder, A medical tube manufacturing apparatus comprising: a control unit having a resin discharge amount function for controlling a discharge resin amount of the second resin extruder; wherein the crosshead includes a die, and the first resin And a stripe spacer for supplying the second resin in the form of a stripe, and a rotation mechanism for rotating the die or the stripe spacer. Further, the control includes the first resin and the second resin. This is a medical tube manufacturing apparatus provided with a resin discharge amount ratio control function of making the total discharge amount of the first resin substantially constant and changing the discharge amount ratio of the first resin and the second resin with time. And it is preferable that the said control part is provided with the rotation speed control function of the said rotation mechanism.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A medical tube according to the present invention will be described with reference to the drawings. FIG. 1 is a front view of an embodiment of the medical tube of the present invention. FIG. 2 is an enlarged sectional view of an intermediate portion of the medical tube shown in FIG. FIG. 3 is a cross-sectional view of FIG.
FIG. 4 is a sectional view taken along line BB of FIG. 2, and FIG.
FIG. 3 is a sectional view taken along line CC of FIG. 2.

The medical tube 1 is made of a flexible first resin 1.
1 is a medical tube formed of a second resin 12 having higher rigidity than the first resin 11. The medical tube 1 includes a flexible distal portion 2 formed only of the first resin 11, a highly rigid proximal portion 3 formed of only the second resin 12, and a distal portion 2. End part 3
And an intermediate portion 4 formed between the
The first resin 11 and the second resin 12 are continuously and alternately wound in a band shape and a spiral shape, and the width of the band of the second resin 12 is increased toward the distal end. It is gradually narrowing. The width of the band of the first resin 11 is
It gradually narrows toward the proximal end. The medical tube 1 includes a distal portion 2, an intermediate portion 4, and a proximal portion 3, and is integrally and continuously formed entirely of a polymer material.

The total length of the medical tube 1 varies depending on the application, but when used for a catheter, 1000
About 1500 mm is preferable, and when it is used for an endoscope, about 1000 to 2000 mm is preferable.
The outer diameter of the medical tube 1 also varies depending on the application, but when used for a catheter, it is 0.7 to 2.0 m.
m is preferable, and when used for an endoscope,
About 1.0 to 3.0 mm is preferable. When used for a catheter, the thickness of the medical tube 1 is 0.05
About 0.3 mm is suitable, and when used for an endoscope, about 0.02 to 0.1 mm is preferable.

The distal end portion 2 is formed only of the flexible first resin 11. As the first resin 11, a thermoplastic resin is desirable, and a polyethylene elastomer, a polypropylene elastomer, a polybutene elastomer,
Thermoplastics such as polyolefin-based elastomers such as ethylene-vinyl acetate copolymer, soft polyvinyl chloride, soft fluorine-based resin, soft methacrylic resin, soft polyphenylene oxide, polyurethane-based elastomer, polyester-based elastomer, polyamide-based elastomer, and styrene-based elastomer Elastomeric materials can be used. Further, a polymer alloy or a polymer blend based on these resins may be used.

The length of the distal end portion 2 varies depending on the application.
About 300 mm is preferable, and when used for an endoscope, about 100 mm to 500 mm is preferable.

Also, the proximal portion 3 of the medical tube 1
Is formed only of the second resin 12 having higher rigidity than the first resin 11. As the second resin 12, a thermoplastic resin is desirable, and an olefin resin such as polyethylene, polypropylene, polybutene, and ethylene-vinyl acetate copolymer or a polyolefin elastomer thereof, a fluororesin or a soft fluororesin, a methacrylic resin, Polyphenylene oxide, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyurethane elastomer, polyester elastomer, polyamide or polyamide elastomer, polycarbonate, polyacetal, styrene resin or styrene elastomer, thermoplastic polyimide, and the like can be used. It is also possible to use polymer alloys or polymer blends based on these resins.

The first resin 11 and the second resin 12
It is necessary to select a material having good compatibility between the above resins from the viewpoint of coextrusion moldability. Good compatibility means that thermodynamic mutual solubility is good. In other words, it means that there is no separation between the two after curing. Specifically, it is desirable to select the same resin for the first resin 11 and the second resin 12. For example, a polyether polyamide block copolymer is selected as the flexible first resin 11 and a nylon 12 is selected as the second resin 12 having high rigidity. A polyolefin-based elastomer (for example, polyethylene elastomer) is used as the resin 11 of the second resin 1 having a high rigidity.
2, a polyethylene or a polyolefin-based elastomer (for example, polyethylene elastomer) harder than the first resin 11 is selected, and both are made of a polyolefin-based resin. Further, as the flexible first resin 11, a polyester-based elastomer (for example, polyester) is used. As the second resin 12 having high rigidity, polyethylene terephthalate or a polyester-based elastomer (for example, polyester elastomer) harder than the first resin 11 is selected, and both are made of a polyester-based resin. It is conceivable that a highly plasticized vinyl chloride resin is selected as the resin 11 and a low plasticized vinyl chloride resin is selected as the second resin 12 having high rigidity, and both are made of a vinyl chloride resin.

The length of the proximal portion 3 of the medical tube 1 varies depending on the application, but when it is used for a catheter, it is preferably about 700 to 1300 mm.
When used for an endoscope, it is preferably about 700 to 1500 mm.

Then, the intermediate portion 4 of the medical tube 1
As shown in FIGS. 1 and 2, the first resin 11 and the second resin 12 are continuously and alternately wound in a strip shape and a spiral shape, and the second resin 12
Is formed so that the width of the band gradually decreases toward the front end side. For this reason, in the intermediate portion 4, the medical tube 1 is gradually softened from the base end toward the distal end. For this reason, since there is no abrupt change point of physical properties, kink hardly occurs, and the tube bends well.

The length of the spiral intermediate portion 4 varies depending on the length of the medical tube 1 and the purpose of use.
About 500 mm is preferable, and when used for an endoscope, about 100 to 700 mm is preferable. The maximum width of the second resin in the spiral portion varies depending on the length of the medical tube 1 and the application, but when used for a catheter, it is preferably about 5 to 20 mm.
When used for an endoscope, it is preferably about 5 to 30 mm.

The width of the second resin 12 is preferably reduced in an arithmetic progression toward the leading end side for each pitch, but may be reduced in an arithmetic progression. When the arithmetic operation becomes narrower, the width L2 of the _second resin 12 at the n-th pitch can be written as the following equation (1).

L ₂ = a− (n−1) d ‥‥ (1) (a: width (maximum width) of the second resin at the start of the spiral at the base end of the intermediate portion 4, d: change amount 0 <d <a / (n-1), n = natural number)

At this time, the first resin 11 and the second resin 12
Is substantially constant, the width L1 of the _first resin 11 at the n-th pitch can be written as in the following equation (2).

L ₁ = nd (d ≦ L ₁ ≦ a) ‥‥ (2)

Therefore, since the length S of the spiral portion (intermediate portion 4) is the sum of the sum of L _{1 and} the sum of L ₂ ,
It can be expressed as in equation (3).

S = n {a− (n−1) d / 2} + n (n + 1) d / 2 = n (a + d) (3)

Since the pitch number n of the spiral part (intermediate part 4) is n = a / d from the equation (2), the equation (3) is
It can be written as in equation (4).

S = a (a + d) / d ‥‥ (4)

For this reason, the length of the spiral portion differs depending on the variation d of the width of the second resin 12. This change amount d
Is preferably 1/9 to 1/4 times the maximum width a of the second resin 12. If the change amount d is less than a / 9, the spiral portion (intermediate portion 4) becomes excessively long. If the change amount d is more than a / 4, the physical properties rapidly change, which is not preferable.

In the medical tube 1 of this embodiment, the second
Is formed so that the width of the resin 12 becomes narrower in an arithmetic progression for each pitch, and the intermediate portion 4 is formed of the first resin 11 and the second resin 12 having higher rigidity in a spiral shape.
In addition, they are alternately wound so that the ratio of the cross-sectional area of the first resin 11 to the cross-sectional area of the second resin 12 is substantially linearly inclined. For this reason, the second resin 12 has a larger sectional area ratio than the first resin 11 as shown in FIG. 3 which is a sectional view taken along the line AA in FIG. Some Figure 4
As shown in FIG. 2, the second resin 12 shifts to a state in which the cross-sectional area ratio is smaller than that of the first resin 11, and furthermore, C-C in FIG.
As shown in FIG. 5 which is a line sectional view, the second resin 12 has changed to a state in which the sectional area ratio is considerably smaller than that of the first resin 11. Since the first resin 11 and the second resin 12 are a combination of highly compatible resins, at the boundary between the two, the first resin 11 and the second resin 12 are microscopically combined. It is considered that they are mixed to form a so-called polymer blend state. Therefore, it is considered that there is no strict interface between the two, and a boundary portion is formed by a mixture of the two.

Next, a medical tube according to another embodiment of the present invention will be described. FIG. 6 is a front view of an embodiment of the medical tube of the present invention. FIG. 7 is an enlarged cross-sectional view of an intermediate portion of the medical tube shown in FIG.

This medical tube 20 is a medical tube 20 formed of a flexible first resin 11 and a second resin 12 having a higher rigidity than the first resin 11. The medical tube 20 includes a flexible distal portion 22 formed only of the first resin 11, a highly rigid proximal portion 23 formed only of the second resin 12, and a flexible distal portion 22 and a proximal side. And an intermediate portion 24 formed between the portions 23. The intermediate portion 24 is located on the proximal side, and the first resin 11
And the second resin 12 are continuously wound alternately in a band shape and a spiral shape, and the width of the band of the second resin 12 is gradually reduced toward the front end side. The formed first spiral part 31 and the first resin 11 and the second resin 12 which are located on the tip side from the first spiral part 31 are continuously wound alternately in a strip shape and a spiral shape, In addition, a second spiral portion 32 is formed so that the width of the band of the second resin 12 gradually decreases toward the front end and the rear end.

The medical tube 20 has a flexible tip 2
2, an intermediate portion 24, and a proximal portion 23;
The whole is integrally and continuously formed of a polymer material. Further, the intermediate portion 24 includes a first spiral portion 31 forming a rigid inclined transition region and a second spiral portion 32 forming a reinforcing portion. The second resin portion which partially forms the first spiral portion 31 and the second spiral portion 32 is continuous in a thin band or linear shape. In other words, the intermediate part 24 includes a connection spiral part (third spiral part) 33 that connects the first spiral part 31 and the second spiral part 32. By providing such a third spiral portion 33, a kink between the first spiral portion 31 and the second spiral portion 32 can be reliably prevented. However, the third spiral part 33 does not necessarily have to be provided.

The medical tube 20 can be suitably used for an ultrasonic catheter, and the reinforcing portion functions effectively by disposing the ultrasonic vibrator portion on the second spiral portion 32 as the reinforcing portion. The outer diameter of the medical tube 20 is 0.6 when used for an ultrasonic catheter.
About 1.5 mm is preferable. When the medical tube 20 is used for an ultrasonic catheter,
About 1000 to 1500 mm is suitable. When used for an ultrasonic catheter, the thickness of the medical tube 20 is preferably about 0.02 to 0.3 mm.

The flexible tip 22 is made of a flexible first resin 11.
It is formed only by. As the first resin 11,
Thermoplastic resin is desirable, polyethylene elastomer,
Polyolefin elastomer such as polypropylene elastomer, polybutene elastomer, ethylene-vinyl acetate copolymer, soft polyvinyl chloride, soft fluororesin, soft methacrylic resin, soft polyphenylene oxide, polyurethane elastomer, polyester elastomer, polyamide elastomer, styrene Thermoplastic elastomer-based materials such as elastomers can be used. Further, a polymer alloy or a polymer blend based on these resins may be used. When used for an ultrasonic catheter, the length of the flexible distal end portion 22 is preferably about 20 to 40 mm.

The proximal portion 2 of the medical tube 20
3 is formed only of the second resin 12 having higher rigidity than the first resin 11. As the second resin 12,
Thermoplastic resins are desirable, and polyethylene, polypropylene, polybutene, olefin resins such as ethylene-vinyl acetate copolymer or their polyolefin elastomers, fluororesins or soft fluororesins, methacrylic resins, polyphenylene oxide, modified polyphenylene ether, polyethylene Terephthalate, polybutylene terephthalate, polyurethane-based elastomer, polyester-based elastomer, polyamide or polyamide-based elastomer, polycarbonate, polyacetal, styrene-based resin or styrene-based elastomer, thermoplastic polyimide, and the like can be used. It is also possible to use polymer alloys or polymer blends based on these resins.

The first resin 11 and the second resin 12
It is necessary to select a material having good compatibility between the above-mentioned resins from the viewpoint of co-extrusion moldability. Good compatibility means that thermodynamic mutual solubility is good. In other words, it means that there is no separation between the two after curing. Specifically, the first
It is desirable to select the same resin for the resin 11 and the second resin 12. For example, a polyether polyamide block copolymer is selected as the flexible first resin 11 and a nylon 12 is selected as the rigid second resin 12,
Both are made of polyamide resin, and flexible first resin
Polyethylene-based elastomer (eg, polyethylene elastomer) is selected as the resin 11 and polyethylene or a polyolefin-based elastomer (eg, polyethylene elastomer) harder than the first resin 11 is selected as the second resin 12 having high rigidity. In addition, a polyester-based elastomer (for example, polyester elastomer) is used as the flexible first resin 11, and polyethylene terephthalate or a polyester-based elastomer (for example, polyester) harder than the first resin 11 is used as the second resin 12 having high rigidity. Elastomer), a polyester resin for both, a highly plasticized vinyl chloride resin as the flexible first resin 11, and a low plasticized vinyl chloride resin as the rigid second resin 12. Such that with both the vinyl chloride resin can be considered. When used for an ultrasonic catheter, the length of the proximal portion 23 is 700 to 1300.
mm is preferable.

Then, the intermediate portion 2 of the medical tube 20
4, as shown in FIGS. 6 and 7, three spiral portions of a first spiral portion 31, a second spiral portion 32, and a third spiral portion 33 are formed. The first spiral portion 31 includes the first resin 11 and the second resin 12.
Are continuously wound alternately in a band shape and a spiral shape, and the width of the band of the second resin 12 is:
It is formed so as to gradually become narrower toward the distal end side. For this reason, in the first spiral portion 31, the medical tube 20 is gradually softened from the base end toward the distal end. For this reason, since there is no abrupt change point of physical properties, kink hardly occurs, and the tube bends well.

The width of the second resin 12 is preferably reduced in an arithmetic progression toward the tip end for each pitch, but may be reduced in an arithmetic progression. As described above, when the arithmetic progression becomes narrow, the width S of the spiral portion can be expressed by the following equation.

S = a (a + d) / d (a: the maximum width of the second resin at the start of the spiral,
d: amount of change)

At this time, the change amount d is preferably 1/9 to 1/4 times the maximum width a of the second resin. Spiral part (intermediate part 4) if the variation d is less than a / 9
Is excessively long, and if it is more than a / 4, the physical properties change rapidly, which is not preferable.

The maximum width of the second resin in the first spiral portion is preferably about 5 to 20 mm when used for an ultrasonic catheter. In the medical tube 20 of this embodiment, the width of the second resin 12 is formed so as to be reduced in an arithmetic progression for each pitch, and the intermediate portion 24 is made of the first resin 11 and the rigidity thereof. The second resin 12 having a high height is spirally wound alternately so that the ratio of the cross-sectional area of the first resin 11 to the cross-sectional area of the second resin 12 is substantially linearly inclined. Therefore, FIG.
As shown in FIG. 4 and FIG.
When the cross-sectional area occupied by the first resin 11 is larger than the cross-sectional area occupied by the first resin 11 (the cross-sectional area ratio of the second resin 12 is large), the cross-sectional area occupied by the second tree toward the distal end side is increased.
Has become smaller than the cross-sectional area occupied by. Since the first resin 11 and the second resin 12 are a combination of highly compatible resins, at the boundary between the two, the first resin 11 and the second resin 12 are microscopically combined. Are mixed to form a so-called polymer blend state. Therefore, it is considered that there is no strict interface between the two, and a boundary portion is formed by a mixture (polymer blend) of the two.

The length of the first spiral portion 31 varies depending on the length of the tube, but when used for an ultrasonic catheter, it is preferably about 100 to 300 mm.

The second spiral portion 32 is located on the distal end side of the first spiral portion 31 and has the first resin 11 and the second
Of the second resin 12 is formed so that the width of the band of the second resin 12 gradually decreases toward the front end side and the rear end side. .

The first spiral portion 31 is the same as the first spiral portion 31 in that the first resin 11 and the second resin 12 are continuously wound alternately in a band shape and a spiral shape. In the second spiral portion 32, the width of the band of the second resin 12 is narrow at the base end side, rapidly widens toward the front end side, the widened width continues for a predetermined distance, and furthermore, at the front end side. It narrows sharply toward the end and ends at the end. When the entire distal end portion is formed only of the first resin 11 and a hard material such as an ultrasonic vibrator or its housing is arranged at that portion, the hard portion contacts the inner wall of the tube,
Rotational unevenness may occur, or the tube may kink in the vicinity. However, by forming such a reinforcing portion (semi-rigid portion), such a problem can be prevented.

In particular, as described above, by forming a portion (reinforcing portion) where the width of the second resin 12 is widened and the predetermined length is maintained in the second spiral portion 32 as described above, reinforcement hardening is more sufficient. By forming a physical property transition region where the physical properties change before and after the reinforcing portion, kink before and after the reinforcing portion can be prevented. In addition, the width of the second resin 12 in the distal end portion and the proximal end portion (two physical property transition regions) 32 of the second spiral portion decreases in an arithmetic progression toward the distal end for each pitch. It is preferable that the width be narrowed in geometric progression. As described above, when the arithmetic progression becomes narrow, the width S of the spiral portion can be expressed by the following equation.

S = a (a + d) / d (a: the maximum width of the second resin at the start of the spiral,
d: amount of change)

At this time, the amount of change d is preferably 1/9 to 1/4 of the maximum width a of the second resin. Spiral part (intermediate part 4) if the variation d is less than a / 9
Is excessively long, and if it is more than a / 4, the physical properties change rapidly, which is not preferable. Since the first resin 11 and the second resin 12 are a combination of highly compatible resins, at the boundary between the two, the first resin 11 and the second resin 12 are microscopically combined. Are mixed to form a so-called polymer blend state. For this reason,
It is considered that there is no strict interface between the two and a boundary portion is formed by a mixture (polymer blend) of the two.

The length of the second spiral portion 32 varies depending on the length of the tube, but when used for an ultrasonic catheter, it is preferably about 30 to 100 mm.
Further, the length of the reinforcing portion where the width of the second resin portion is substantially constant is preferably about 2 to 10 mm. The length of the transition region formed before and after the reinforcing portion is 15 to 50.
mm is preferable. In addition, the maximum width of the second resin in the second spiral portion is preferably about 1 to 5 mm when used for an ultrasonic catheter.

The medical tube 20 of this embodiment is
Then, a third spiral part 33 is provided. The third spiral part 33 includes the first spiral part 31 and the second spiral part 31.
Continuous with the second resin portion of the spiral portion 32 of
A second resin portion is formed in a narrow band shape or a linear spiral shape having substantially the same width or thickness. In addition,
Instead of the third spiral portion 33 having the same width or thickness and continuing in a spiral shape, the first spiral portion 31 may be extended to be continuous with the second spiral portion 32. In this case, the width of the band of the second resin portion always changes except for the above-described reinforcing portion.
As described above, since the first spiral portion 31 and the second spiral portion 32 are continuous, a kink between the first spiral portion 31 and the second spiral portion 32 can be reliably prevented.

Next, an apparatus for manufacturing a medical tube will be described. FIG. 8 is a conceptual diagram of an embodiment of a medical tube manufacturing apparatus. The medical tube manufacturing apparatus 50 of this embodiment supplies a crosshead 53, a first resin extruder 51 that supplies the first resin 11 to the crosshead 53, and supplies a second resin 12 to the crosshead 53. A second resin extruder 52 to perform, and a resin discharge amount control unit 5 for controlling the discharge resin amount of the first resin extruder 51 and the second resin extruder 52
4 is provided. The cross head 53 includes a die 65, a stripe spacer 63 for supplying the first resin 11 and the second resin 12 to the die 65 in a stripe shape, and a die 65 or a stripe spacer 6.
And a rotation mechanism for rotating 3. Then, the control unit 54 makes the total discharge amount of the first resin 11 and the second resin 12 substantially constant, and the first resin 11 and the second resin
A resin discharge amount ratio control function of changing the discharge amount ratio of the resin 12 is provided.

The medical tube manufacturing apparatus 50 includes the first
A first resin extruder 51 for supplying the first resin 11 and a second resin extruder 52 for supplying the second resin 12 to the crosshead 53 are provided. A known extruder can be used. As the first resin 11 and the second resin 12, those described above can be used.

The first resin 11 and the second resin 12 are
It passes through the first adapter 61 and the second adapter 62 and is supplied to the die 65 without being mixed.
Note that a gear pump may be provided in the adapter portion to perform accurate dimensional control.

The first resin 11 and the second resin 12 supplied to the crosshead 53 pass through respective independent flow paths inside the crosshead 53, then pass through the stripe spacer 63, and each has an arbitrary stripe slot. It is deformed into a shape, passes through the channel formed by the die 65 and the nipple 64 while being joined, and is extruded from the tip of the die 65.

The structure of the crosshead 53 is such that a core wire or a compressive fluid for regulating the inner diameter of the tube can be introduced from the rear portion, and the tube is formed by the resin extruded at the front portion. Has become. The shape of the obtained tube is set according to the shape of the core wire, the flow rate of the compressible fluid, the shape of the stripe slot, the shape of the die 65, the shape of the nipple 64, the amount of resin discharged, and the take-up speed. In the method of extrusion molding while covering the core wire, a tube can be obtained by stretching and removing the core wire after forming the tube.

The crosshead 53 has a rotating mechanism for the dies 65. Since the crosshead 53 has a rotation mechanism in the circumferential direction, it is desirable that the crosshead 53 has an alignment-free structure. The rotating mechanism for rotating the die 65 in the circumferential direction includes a sliding ring (not shown) provided between a die holder 66 for fixing the die 65 and a die nut 81, and a die holder 66.
A sliding ring (not shown) provided between the die holder and the crosshead 53; and a bevel gear 67 provided on a die holder 66. The die holder 66 rotates in a circumferential direction (a direction orthogonal to the extrusion direction) by rotating a motor 69 provided with a bevel gear 68 that meshes with the bevel gear 67 on the die holder side, and the die fixed to the die holder also rotates. I do. The structure of the gear is not limited to the bevel gear, and a worm gear or another gear may be used. Further, the method of transmitting the rotational torque of the motor is not limited to the gear type, and a belt type, a viscous type, or another method may be used.

By controlling the rotation speed of the die holder 66 and the supply amount of the resin, the spiral width and the spiral pitch of the first resin 11 and the second resin 12 can be arbitrarily set. The control unit 54 of the medical tube manufacturing apparatus 50 of this embodiment includes a resin discharge amount control function,
It has both functions of controlling the rotation speed of the dice (die holder).

In the illustrated embodiment, the tube is manufactured from the first resin side (the distal end side of the tube) while the rotation speed of the die holder 66 is kept constant. It has a function of inputting the total amount of discharged resin per unit time (TV), inputting the intermediate part forming time (x: seconds), inputting the rotation speed of the die holder, and storing them. Then, the control unit includes the following (A),
Equations (B) and (C) are stored.

V1 is a discharge amount of the first resin 11 per unit time, and V2 is a discharge amount of the second resin 12 per unit time.

TV = V1 + V2 (A) V1 = TV (1−t / x) (B) V2 = TV · t / x (C)

Therefore, when the formation of the intermediate part 4 is started, the first resin 11
Discharge amount decreases, the discharge amount of the second resin 12 increases,
When the formation time elapses (t = x), the discharge amount of the first resin 11 becomes 0, and the formation of the intermediate portion 4 ends.

The second resin side (the base end side of the tube)
When a tube is manufactured, V1 and V2 are interchanged, and the equations (D), (E), and (F) are stored.

TV = V1 + V2 (D) V2 = TV (1−t / x) (E) V1 = TV · t / x (F)

Therefore, when the formation of the intermediate portion 4 is started, as the time elapses (t increases), the second resin 12
Discharge amount decreases, the discharge amount of the first resin 11 increases,
When the formation time elapses (t = x), the discharge amount of the second resin 12 becomes 0, and the formation of the intermediate portion 4 ends. By performing such control, the medical tube 1 as shown in FIGS. 1 to 5 can be manufactured.

In addition to the above-described control of the resin discharge amount ratio, by appropriately performing a rotation speed change control for changing the rotation speed of the die holder 66, the medical tube 20 as shown in FIGS. Can be manufactured. According to the manufacturing apparatus 50, when the supply amounts of the first resin 11 and the second resin 12 are made equal, a spiral tube having the same spiral width is formed. Also, the first
When the take-up speed is increased in a state where the supply amounts of the resin 11 and the second resin 12 are fixed, the spiral width and the spiral pitch become larger, and a thinner and thinner spiral tube is formed. When the supply amount of the first resin 11 is larger than the supply amount of the second resin 12, a spiral tube in which the spiral width of the first resin 11 is larger than the spiral width of the second resin 12 is formed. When the rotational speed of the die is gradually increased while the supply amounts and the take-up speeds of the first resin 11 and the second resin 12 are fixed, a tube having the same size and a spiral width and a spiral pitch gradually reduced is formed. .

In the above-described embodiment, the die holder 66 is rotated. However, the present invention is not limited to this, and the stripe spacer 63 may be rotated. If possible, the nipple 64 may be rotated. You may be comprised so that it may be performed. Further, these rotations may be combined. In this case, the design of the sliding part between the rotating part and the fixed part is important.For example, a method in which a fine clearance is provided in the sliding part to rotate while allowing resin to leak, and a bearing is provided in the sliding part And a method of equipping the sliding portion with a material having a low dynamic friction coefficient.

Further, as in the medical tube manufacturing apparatus 80 shown in FIG. 9, the crosshead 53 is equipped with two flow adjustment gates 71 and 72 for continuously changing the cross-sectional area of the stripe slot. Alternatively, the supply amount of one resin may be controlled.

By using the flow adjustment gates 71 and 72, it is possible to change the cross-sectional area of the stripe of the first resin 11 or the second resin 12, or to interrupt the supply. When one of the first resin 11 and the second resin 12 is shut off using the flow adjustment gates 71 and 72, only the other resin is supplied.
A single-layer tube of the resin 11 or the second resin 12 can be formed.

Therefore, for example, it is easy to form a single-layer tube made of a soft first resin 11 when it is desired to provide trackability, and to form a single-layer tube made of a hard second resin 12 when it is desired to provide pushability. Become. In addition, such a flow adjustment gate 7
Even without providing 1, 72, a single-layer tube can be manufactured by stopping one extruder.

The method of mounting the flow adjustment gates 71 and 72 on the crosshead 53 is not particularly limited. For example, a method of mounting the flow adjustment gates 71 and 72 in the outer peripheral direction of the stripe spacer 63 is preferable in terms of the structure of the crosshead 53. The shape of the flow adjustment gates 71 and 72 is not particularly limited. For example, it is desirable that the shape of the flow adjustment gates 71 and 72 be such that the stripe slot can be mechanically actuated by an external force when closing the slot and the stripe slot can be actuated by resin pressure when the stripe slot is opened.

As shown in FIG. 9, a method of operating the flow adjustment gates 71 and 72 on the crosshead 53 and an example of the shape of the flow adjustment gates 71 and 72 are shown. When closing the stripe slot, the rack gears 74 and 76 provided outside the crosshead 53 are connected to the pinion gears 7 attached to the motors 77 and 78.
3, 75, the rack gears 74, 7
6 moves the flow adjustment gates 71 and 72 by the force pressing the flow adjustment gates 71 and 72 toward the center of the crosshead 53. On the other hand, when opening the stripe slot, the rack gears 74 and 76 are returned to their original positions, and the flow adjustment gate 7 having a certain angle with respect to the vector direction of the pressure applied to the resin flow path.
1, 72 are moved by being pushed up in the outer peripheral direction of the crosshead 53.

The rack gears 74 and 76 and the pinion gears 73 and 75 need to be provided for the first resin and the second resin. Further, in order to prevent the resin pressure from sharply increasing when the stripe slot is closed, it is desirable that the rotation control of the motors 77 and 78 be linked with the resin supply machine. Also, the flow adjustment gates 71, 72
The method of operating is not limited to the rack-and-pinion type, and a cam type, a hydraulic type, or another method may be used.

[0075]

As described above, the medical tube of the present invention has a flexible first tube.
And a second resin having a higher rigidity than the first resin, wherein the medical tube is a flexible distal portion formed only of the first resin. A high-rigidity proximal end portion formed only of the second resin, and an intermediate portion formed between the distal end portion and the proximal end portion. The first resin and the second resin are continuously and alternately wound in a band shape and a spiral shape, and the width of the band of the second resin gradually increases toward the front end side. It is getting smaller.

For this reason, it has pushability, trackability, torque transmission, and kink resistance, as well as flexibility at the tip, and there is no sudden change in the physical properties in the middle part, and the physical properties change smoothly. Kink is less likely to occur and the tube can be bent well, which is effective for medical use.

The medical tube of the present invention is a medical tube formed of a flexible first resin and a second resin having a higher rigidity than the first resin, wherein the medical tube is Are formed between the flexible distal end and the proximal end, the flexible distal end formed solely of the first resin, the high rigid proximal end formed solely of the second resin. And the intermediate portion is located on the proximal end side, and the first resin and the second resin are continuously and alternately wound in a strip shape and a spiral shape. A first spiral portion formed so that the width of the second resin band gradually narrows toward the distal end, and a width of the second resin belt is located closer to the distal end than the first spiral portion;
The first resin and the second resin are continuously and alternately wound in a band shape and a spiral shape, and the width of the band of the second resin gradually increases toward the front end side and the rear end side. A second spiral portion formed to be narrow;

Therefore, it has pushability, trackability, torque transmission, and kink resistance, as well as flexibility at the tip, and the first spiral portion at the intermediate portion has no sharp change point in physical properties and physical properties. Because of the gradual change, kink is less likely to occur, and the tube can be well curved. Further, since the second spiral portion is a reinforcing portion formed so that the physical properties do not suddenly change,
Even if a hard member (for example, a housing for an ultrasonic vibrator) is housed therein, it is hardly damaged by the hard member, and
Since there is little kink before and after the reinforcing portion, it can be effectively used for a catheter that requires the use of a hard member such as an ultrasonic catheter.

Further, the medical tube manufacturing apparatus of the present invention comprises a crosshead, a first resin extruder for supplying a first resin to the crosshead, and a first resin extruder for supplying a second resin to the crosshead. 2. A medical tube manufacturing apparatus comprising: a resin extruder of No. 2; and a control unit having a resin discharge amount function of controlling a discharge resin amount of the first resin extruder and the second resin extruder. A cross head comprising: a dice; a stripe spacer for supplying the first resin and the second resin to the dice in a stripe shape;
A rotation mechanism for rotating the dice or the stripe spacer, and the control further comprises:
And a resin discharge amount ratio control function for changing the discharge amount ratio between the first resin and the second resin with time by making the total discharge amount of the first resin and the second resin substantially constant. For this reason, the medical tube as described above can be manufactured continuously and integrally.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the medical tube of the present invention.

FIG. 2 is an enlarged sectional view of an intermediate portion of the medical tube shown in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a sectional view taken along line CC of FIG. 2;

FIG. 6 is a front view of an embodiment of the medical tube of the present invention.

FIG. 7 is an enlarged sectional view of an intermediate portion of the medical tube shown in FIG. 6;

FIG. 8 is a conceptual diagram of an embodiment of a medical tube manufacturing apparatus.

FIG. 9 is a conceptual diagram of another embodiment of the medical tube manufacturing apparatus.

[Explanation of symbols]

 Reference Signs List 1 medical tube 2 distal end portion 3 proximal end portion 4 intermediate portion 11 first resin 12 second resin 20 medical tube 22 flexible distal end portion 23 proximal end portion 24 intermediate portion 31 first spiral portion 32 first 2 spiral section 33 3rd spiral section 50 Medical tube manufacturing device

Claims (7)

[Claims] 1. A medical tube formed of a flexible first resin and a second resin having a higher rigidity than the first resin, wherein the medical tube comprises only the first resin. A flexible distal portion formed by the above, a highly rigid proximal portion formed only of the second resin, and an intermediate portion formed between the distal portion and the proximal portion. The intermediate portion is in a state in which the first resin and the second resin are continuously wound alternately in a band shape and a spiral shape, and the width of the band of the second resin is provided. Is a medical tube characterized by gradually narrowing toward the distal end. 2. The medical tube according to claim 1, wherein the width of the first resin gradually narrows toward a base end. 3. A medical tube formed of a flexible first resin and a second resin having a higher rigidity than the first resin, wherein the medical tube comprises only the first resin. A flexible distal portion formed by the second resin, a highly rigid base end portion formed only by the second resin, and an intermediate portion formed between the flexible distal end portion and the base end portion, The intermediate portion is located on the base end side, in a state where the first resin and the second resin are continuously wound alternately in a strip shape and a spiral shape, and The width of the resin band is gradually narrowed toward the distal end, and the first spiral portion is located on the distal side with respect to the first spiral portion. Resin is continuously wound alternately in a strip shape and a spiral shape, and the second tree A medical tube comprising: a second spiral portion formed such that a width of a fat band gradually decreases toward a front end side and a rear end side. 4. The first resin and the second resin,
4. A combination of resins having high compatibility.
The medical tube according to any one of the above. 5. The medical tube according to claim 1, wherein the thickness of the medical tube is substantially uniform. 6. A crosshead and a first head attached to the crosshead.
A first resin extruder for supplying a second resin to the crosshead, a second resin extruder for supplying a second resin to the crosshead, and a discharge resin of the first resin extruder and the second resin extruder. A medical tube manufacturing apparatus comprising: a control unit having a resin discharge amount function for controlling an amount of the resin, wherein the crosshead includes a die, and the first resin and the second resin formed on the die in a stripe shape. A stripe spacer for supplying, and a rotating mechanism for rotating the dice or the stripe spacer, and further, the control is such that a total discharge amount of the first resin and the second resin is substantially constant; A medical tube manufacturing apparatus comprising a resin discharge amount ratio control function of changing a discharge amount ratio of a first resin and a second resin over time. 7. The medical tube manufacturing apparatus according to claim 6, wherein the control unit has a rotation speed control function of the rotation mechanism.