JP2000271208A - Medical catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent from getting a tendency to bend even if a force that may cause to bend is applied during use, by bending a metal tubular member 90 degrees with a specified radius of curvature and holding it for a specified period and then releasing from bending, in a medical catheter having a metal tubular member in a part. SOLUTION: In a medical catheter having one or more lumens inside and having a metal tubular member 1 in a part thereof, where molybdenum or titanium, or the like, is used as a metal material, the tubular member is bent 90 degrees with a radius of curvature 50 times the outside diameter A (50A). Namely, the tubular member 1, one end of which is fixed, is bent along the circumference of a column 2 having a radius 50 times the tubular member 1 so that the angle of the extended lines of the unbent portions at both ends of the tubular member 1 may be 90 degrees. After this bent condition is held for 1 minute, by releasing from bending, the angle of bending occurring in the tubular member 1 is held within 15 degrees, thereby reducing a decline in performance due to elastic deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal tubular member used for a medical catheter and a medical catheter using the same.

[0002]

2. Description of the Related Art A medical catheter is inserted into a body and used for treatment, drug administration, and the like. Among them,
Medical catheters that need to enter deep inside the body are required to have good followability and operability so that the operation at hand can be easily transmitted to the tip so that they can enter without difficulty along the passage in the body. Generally, the proximal portion, which is close to the hand, is rigidly configured, and the distal portion, which is the distal direction, is generally flexible compared to the proximal portion.

[0003] As the material of the catheter, various materials are used according to the required performance, and a synthetic resin resin material having both flexibility and workability is most often used. However, as described above, in particular, when it is desired to configure the hand rigidly, when it is desired to suppress crushing against compression from other instruments or body tissues used together, a metal tubular member is used as a constituent material of a medical catheter. In some cases.

[0004]

However, when a metal tubular member is used as a constituent member of a medical catheter, the metal generally tends to be plastically deformed and tends to bend, and therefore, once for some reason. When deformed in the above, the bent state is maintained as it is, and in many cases, subsequent use is impossible or operability is remarkably deteriorated.

[0005] An object of the present invention is to provide a medical catheter which suppresses performance degradation due to plastic deformation.

[0006]

The medical catheter shown in the present invention is a medical catheter having one or more lumens inside and a metal tubular member at least partially. When the metal tubular member is bent at 90 degrees with a radius of curvature 50 times (50A) of its outer diameter (A) and held for 1 minute, and then released, the bending angle generated in the metal tubular member Is a medical catheter characterized by being less than 15 degrees, or a medical catheter having one or more lumens therein, at least partially having a metal tubular member, When the metal tubular member is bent at 90 degrees with a radius of curvature 35 times (35A) of its outer diameter (A), held for 1 minute, and then released, the bending angle generated in the metal tubular member is 30. Specially Medical catheters and or,,
A medical catheter having one or more lumens therein and a metal tubular member at least partially, wherein the metallic tubular member has an outer diameter (A) of 2 mm.
A medical catheter characterized in that when it is bent to 90 degrees with a radius of curvature of 5 times (25A), held for 1 minute, and then released, the bending angle generated in the metal tubular member is within 35 degrees. In view of the above, it is an object of the present invention to provide a medical catheter in which a decrease in performance due to plastic deformation is suppressed, and to solve the above-mentioned problems.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the medical catheter according to the present invention will be described below. Although the present invention will be described in detail using a dilatation catheter which is one type of medical catheter, it is particularly limited to a dilatation catheter as long as it is a medical catheter having a metal tubular member at least in part. It is possible to apply.

In the present invention, a certain kind of stainless steel is used as an embodiment, but the present invention is not particularly limited thereto, and a metal tube-shaped member having the characteristics shown in the claims of the present invention is used for medical devices. Any material that can be used safely can be suitably applied. For example, in addition to stainless steel, carbon steel,
Nickel alloys, nickel-iron alloys, titanium-nickel alloys and the like can be suitably used.

Even if the metal has the same composition, its physical properties change depending on the conditions at the time of processing. Therefore, it is necessary to process and adjust the metal so as to exhibit the characteristics in the range shown in the claims of the present invention. For example, the properties of stainless steel can be controlled by solution heat treatment, quenching, and tempering, but the strength, hardness, and creep characteristics are easily controlled, especially by the conditions of solution heat treatment and tempering. Can be used. The temperature conditions for solution heat treatment and tempering vary depending on the steel composition, but in general, if the temperature is too low,
If the structure is not sufficiently recrystallized and the temperature is too high, the strength tends to decrease due to coarsening of crystal grains, and there is an effective range depending on the type of steel. Within this range, the case where the treatment is performed under a lower temperature condition may be more advantageous for the present invention in some cases. The solution heat treatment, the processing temperature, the holding time, the cooling rate, which are the conditions at the time of tempering, are intended to be in an optimal state as shown in the claims of the present invention, the shape of the material to be heat treated, Size,
It should be set in consideration of the surrounding environmental conditions, and is not limited to the range and value of the embodiment of the present invention.

[0010] Among stainless steels, molybdenum or titanium-containing stainless steels are less likely to cause high-temperature temper embrittlement, and at the same time, have a higher tempering softening reduction property. preferable. Of the stainless steels containing molybdenum or titanium, AISI NO. 316, 316L, 317, 3
21, 416, 430F, and 430T can be preferably used from the viewpoint of processability, and from the viewpoint of safety performance on living bodies, 31
6, 321, 430F are particularly preferred.

Bending a metal tubular member to 90 degrees with a radius of curvature of 50 times (50A) its outer diameter (A) means a method as shown in FIG. That is, the metal tubular member having one end fixed is formed so that the extension line angle of the unbent portions at both ends of the cylinder is 90 degrees along the circumferential direction of the cylinder having a radius of 50 times that of the metal tubular member. It is a method of bending. The bending angle is the angle of the intersection of the extensions of the straight portions of the bent member as shown in FIG.

The metal tubular member is bent to 90 degrees with a curvature radius of 35 times (35A) the outer diameter (A), and the metal tubular member has a curvature 25 times (25A) the outer diameter (A). The method of bending at a radius of 90 degrees follows the above method.

As a method of evaluating the degree of plastic deformation of another metal tubular member, an arbitrary point on the metal tubular member is fixed, a weight is applied to another point, and the bending is maintained at a certain angle for a certain time and then released. In addition, a method of examining the elasticity of a needle tube having a bending angle generated in a metal tubular member is also generally used, and when this method is applied, a result corresponding to the evaluation method of the present invention is obtained. Is more preferable because a stable result can be obtained.

In addition to the above-mentioned methods, there are various methods for evaluating plastic deformation. The evaluation methods of the present invention correspond to the results, and it is shown that the tube of the present invention is excellent in other evaluation methods. .

The position and the position of the metallic tubular member in the medical catheter of the present invention are not particularly limited. However, in many cases, the position closer to the proximal side of the catheter is more preferable. Alternatively, a part of the catheter may be constituted only by the metal tubular member, and the metallic tubular member may be present as a core material and a reinforcing material. Further, the surface may be arranged in a state where the surface is covered with a synthetic resin.

The term "proximal" as used in the present invention refers to a direction that is present outside the body when using the catheter and is close to the user's hand, while "distal" refers to a direction that exists inside the body when used. Direction from the hand of the person.

[0017]

(Example 1) Using 316 stainless steel, a tube having an outer diameter of 0.70 mm and an inner diameter of 0.59 mm was formed by cold drawing, and then subjected to a solution heat treatment at about 1093 ° C. for a holding time of 10 minutes. A medical dilatation catheter was prepared by arranging it as a metallic tubular member on the proximal side of the dilatation catheter having the structure shown in FIG. (Example 2) Using 316 stainless steel, an outer diameter of 0.70
mm, a tube having an inner diameter of 0.59 mm is formed by cold drawing, and then subjected to a solution heat treatment at about 982 ° C. for a holding time of 10 minutes to produce a metal tube on the proximal side of the dilatation catheter having the structure shown in FIG. A medical dilatation catheter was prepared by arranging it as a shape member. (Example 3) An outer diameter of 0.70 using 321 stainless steel
A tube having a diameter of 0.59 mm and an inner diameter of 0.59 mm is formed by cold drawing, and then subjected to a solution heat treatment at about 1093 ° C. for a holding time of 10 minutes to produce a metal tube on the proximal side of the dilatation catheter having the structure shown in FIG. A medical dilatation catheter was prepared by arranging it as a member. (Example 4) Using 430F stainless steel, an outer diameter of 0.7
After forming a tube having a diameter of 0 mm and an inner diameter of 0.59 mm by cold drawing, a tempering treatment is performed at about 816 ° C. for a holding time of 3 minutes to produce a metal tube on the proximal side of the dilatation catheter having the structure shown in FIG. A medical dilatation catheter was prepared by arranging it as a shape member. (Comparative Example 1) An outer diameter of 0.70 using 304 stainless steel
After forming a tube having a diameter of 0.59 mm and a diameter of 0.59 mm by cold drawing, a solution heat treatment was performed at about 1093 ° C. for a holding time of 10 minutes to produce a metal tube on the proximal side of the dilatation catheter having the structure shown in FIG. A medical dilatation catheter was prepared by arranging them as members. Comparative Example 2 A commercially available dilatation catheter having a metal tubular member (304 stainless steel outer diameter 0.70 mm, inner diameter 0.48 mm) as a constituent member was designated as Comparative Example 2.

The above Examples 1 to 4 and Comparative Example 1
2. For each catheter having an outer diameter of 0.70 mm, bend at 90 ° with a curvature radius of 14.3 times (10 mm) the outer diameter of 0.70 mm, hold for 1 minute, and release.
The bending angle generated in each metal tubular member was measured.

Similarly, for each catheter having an outer diameter of 0.70 mm, 21.4 having an outer diameter of 0.70 mm is used.
Times (15 mm), 28.6 times (20 mm), 35.7 times (25 mm), 42.9 times (30 mm), 50 times (35 mm)
mm), 57.1 times (40 mm), 64.3 times (45 m
m), when bent at 90 degrees with a radius of curvature of 71.4 times (50 mm), held for 1 minute, and then released, the bending angle generated in each metal tubular member was measured.

FIG. 5 shows the bending angles generated when the catheters of Examples 1 to 4 and Comparative Examples 1 and 2 were bent at the respective radii of curvature. As shown in FIG. 5, Examples 1 to 4 of the present invention have an outer diameter of 0.70 mm.
When it was bent at 90 degrees with a radius of curvature of 50 mm (35 mm) of 90 mm, held for 1 minute, and then released, the bending angle generated in each metallic tubular member was 15 degrees or less. On the other hand, in Comparative Examples 1 and 2, both were 20 degrees or more, indicating that plastic deformation was more likely to occur than in the present invention.

The first to fourth embodiments of the present invention are characterized in that when each of them is bent at 90 degrees at a radius of curvature of 28.6 times (20 mm) the outer diameter of 0.70 mm, held at 90 ° for 1 minute, and then released, each metal The bending angle generated in the tubular member was 30 degrees or less.

Since the angle of curvature that occurs when the radius of curvature to be bent becomes large becomes small, the first to fourth embodiments of the present invention bend at 90 degrees with a radius of curvature 35 times the outer diameter of 0.70 mm and hold for 1 minute. When released, the bending angle generated in each metallic tubular member is 30 degrees or less.

On the other hand, Comparative Examples 1 and 2 had an outer diameter of 0.70 m.
When it was bent at 90 degrees with a radius of curvature of 35.7 times (25 mm) m (25 mm), held for 1 minute, and then released, the bending angle generated in each metallic tubular member was greater than 30 degrees. Since the bending angle that occurs when the bending radius of curvature becomes smaller becomes larger, the comparative examples 1 and 2 have the outer diameter of 0.70 mm.
When bent at 90 degrees with twice the radius of curvature, held for 1 minute, and then released, the bending angle generated in each metallic tubular member was 3
It is clearly larger than 0 degrees, indicating that plastic deformation is more likely to occur than in the present invention. Further, Embodiments 1 to 4 of the present invention
Is bent at 90 degrees with a radius of curvature of 21.4 times (15 mm) the outer diameter of 0.70 mm, held for 1 minute, and released.
The bending angle generated in each metal tubular member was 35 degrees or less.

Since the angle of curvature that occurs when the radius of curvature to be bent becomes large becomes small, the first to fourth embodiments of the present invention bend at 90 degrees with a radius of curvature 25 times the outer diameter of 0.70 mm and hold for 1 minute. When released, the bending angle generated in each metallic tubular member is 35 degrees or less.

On the other hand, Comparative Examples 1 and 2 had an outer diameter of 0.70 m.
When it was bent at 90 degrees at a radius of curvature of 28.6 times (20 mm) m, held for 1 minute, and then released, the bending angle generated in each metal tubular member was 40 degrees or more. Since the bending angle that occurs when the bending radius of curvature decreases becomes large, Comparative Examples 1 and 2 are bent at 90 degrees with a radius of curvature 25 times the outer diameter of 0.70 mm, held for 1 minute, and then released. The bending angle generated in the metal tubular member is 3
It was clearly larger than 5 degrees, indicating that plastic deformation is more likely to occur than in the present invention. (Example 5) Using 316 stainless steel, an outer diameter of 0.60
A tube having a diameter of 0.45 mm and an inner diameter of 0.45 mm was produced under the same production conditions as in Example 2, and was placed as a metal tubular member on the proximal side of the dilatation catheter having the structure shown in FIG. 3 to produce a medical dilatation catheter. . (Example 6) Using 321 stainless steel, outer diameter 0.60
A tube having a diameter of 0.45 mm and an inner diameter of 0.45 mm was produced under the same production conditions as in Example 3, and was arranged as a metal tubular member on the proximal side of the dilatation catheter having the structure shown in FIG. 3 to produce a medical dilatation catheter. . (Comparative Example 3) 304 stainless steel, outer diameter 0.60
A tube having a diameter of 0.45 mm and an inner diameter of 0.45 mm is formed by cold drawing, and then subjected to a solution heat treatment at about 1093 ° C. for a holding time of 10 minutes to produce a metal tube on the proximal side of the dilatation catheter having the structure shown in FIG. A medical dilatation catheter was prepared by arranging them as members. Comparative Example 4 Comparative Example 4 was a commercially available dilatation catheter having a metal tubular member (304 stainless steel, outer diameter 0.60 mm, inner diameter 0.45 mm) as a constituent member.

The above Examples 5 and 6 and Comparative Examples 3 and 4
When each catheter having an outer diameter of 0.60 mm is bent at 90 degrees at a radius of curvature of 16.7 times (10 mm) the outer diameter of 0.60 mm, held for 1 minute, and then released, each metal tube The bending angle generated in the shaped member was measured.

Similarly, for each catheter having an outer diameter of 0.60 mm, 25 times (15 mm), 33.3 times (20 mm), 37.5 (2
2.5 mm), 41.7 times (25 mm), 50 times (30
mm), 58.3 times (35 mm), 66.7 times (40 m
m), 75 times (45 mm), 83.3 times (50 mm) when bent at 90 degrees with a radius of curvature, held for 1 minute, and released
The bending angle generated in each metal tubular member was measured.

As a result of the above, FIGS.
The bending angles generated when the catheters of Comparative Examples 3 and 4 were bent at each radius of curvature are shown. As shown in FIG.
In Examples 5 and 6 of the present invention, 50
When it was bent to 90 degrees at a double (30 mm) radius of curvature, held for 1 minute, and then released, the bending angle generated in each metallic tubular member was 15 degrees or less. On the other hand, in Comparative Examples 3 and 4, both were 20 ° or more, indicating that plastic deformation was more likely to occur than in the present invention.

The fifth and sixth embodiments of the present invention have a curvature radius of 33.3 times (20 mm) the outer diameter of 0.60 mm.
When bent at 0 degree and held for 1 minute and then released, the bending angle generated in each metal tubular member was 30 degrees or less.

Since the angle of curvature that occurs when the radius of curvature to be bent becomes large becomes small, the fifth and sixth embodiments of the present invention bend at 90 degrees with a radius of curvature 35 times the outer diameter of 0.60 mm and hold for 1 minute. When released, the bending angle generated in each metallic tubular member is 30 degrees or less.

On the other hand, in Comparative Example 3, when it was bent at 90 degrees at a radius of curvature of 37.5 times (22.5 mm) its outer diameter of 0.60 mm, held for 1 minute, and then released, it was generated on a metal tubular member. The resulting bending angle was 33 degrees. The smaller the radius of curvature to bend, the greater the bend angle that occurs,
Comparative Example 3 was bent at 90 degrees with a radius of curvature of 35 times the outer diameter of 0.60 mm, held for 1 minute, and then released, the bending angle generated in the metal tubular member was clearly larger than 30 degrees, It was shown that plastic deformation is more likely to occur than in the present invention.

Comparative Example 4 had an outer diameter of 0.60 mm.
When bent at 90 degrees with a radius of curvature of 5 times (22.5 mm), held for 1 minute, and released, the bending angle generated in each metal tubular member was 31 degrees. Since the bending angle generated when the radius of curvature to be bent becomes smaller becomes larger, the comparative example 3 has a curvature radius of 35 times the outer diameter of 0.60 mm and 9
When bent at 0 degree and held for 1 minute and then released, the bending angle generated in the metal tubular member was clearly larger than 30 degrees, indicating that plastic deformation is more likely to occur than in the present invention.

In addition, the fifth and sixth embodiments of the present invention show that each metal tube is bent when it is bent at 90 degrees at a radius of curvature 25 times (15 mm) its outer diameter 0.60 mm, held at 90 degrees for 1 minute, and then released. The bending angle generated in the member was 35 degrees or less.

On the other hand, Comparative Examples 3 and 4 have an outer diameter of 0.60 m.
m at a radius of curvature of 25 times (15 mm)
When the metal tube-shaped member was released after being held for about one minute, the bending angle generated in each metal tubular member was 38 degrees or more, indicating that plastic deformation was more likely to occur than in the present invention. (Example 7) Using 316 stainless steel, outer diameter 1.00
A tube having a diameter of 0.72 mm and an inner diameter of 0.72 mm was produced under the same production conditions as in Example 2, and was arranged as a metal tubular member on the proximal side of the dilatation catheter having the structure shown in FIG. 4 to produce a medical dilatation catheter. . (Comparative Example 5) 304 stainless steel, 1.00 outer diameter
A tube having a diameter of 0.72 mm and an inner diameter of 0.72 mm was formed by cold drawing, and then subjected to a solution heat treatment at about 982 ° C. for a holding time of 10 minutes to produce a metal tube on the proximal side of the dilatation catheter having the structure shown in FIG. A medical dilatation catheter was prepared by arranging them as members.

Each of the catheters of Example 7 and Comparative Example 5 having an outer diameter of 1.00 mm was bent at 90 degrees with a radius of curvature 20 times (20 mm) the outer diameter of 1.00 mm. When released after holding for 1 minute, the bending angle generated in each metal tubular member was measured.

Similarly, for each of the above catheters having an outer diameter of 0.70 mm, 25 times (25 mm), 30 times (30 mm), and 35 times (35 m) of the outer diameter of 1.00 mm.
m), when it was bent at 90 degrees with a radius of curvature of 40 times (40 mm) and 50 times (50 mm), held for 1 minute, and then released, the bending angle generated in each metallic tubular member was measured.

As a result, FIG. 7 shows the bending angles generated when the catheters of Example 7 and Comparative Example 5 were bent at the respective radii of curvature. As shown in FIG. 7, Example 7 of the present invention has a 50 times (50 m) outer diameter of 1.00 mm.
When the metal tube-shaped member was bent to 90 degrees at the radius of curvature of m), held for 1 minute, and then released, the bending angle generated in each metal tubular member was 15 degrees or less. On the other hand, Comparative Example 5 was larger than 20, indicating that plastic deformation was more likely to occur than in the present invention.

In the seventh embodiment of the present invention, the outer diameter is 1.
When bent at 90 degrees with a curvature radius 35 times (35 mm) of 00 mm, held for 1 minute, and released, the bending angle generated in each metal tubular member was 30 degrees or less. On the other hand, Comparative Example 5 was larger than 30 degrees, indicating that plastic deformation was more likely to occur than in the present invention.

In the seventh embodiment of the present invention, the outer diameter is 1.
When bent at 90 degrees at a radius of curvature 25 times (25 mm) of 00 mm, held for 1 minute, and released, the bending angle generated in each metallic tubular member was 35 degrees or less. In contrast, Comparative Example 5 was larger than 35, indicating that plastic deformation was more likely to occur than in the present invention.

The above Comparative Examples 1 to 5 were medical catheters in which the metal tubular member was easily plastically deformed and easily bent when used.

Examples 1 to 7 of the present invention shown above
Was a medical catheter having favorable characteristics, in which the metal tube-shaped member portion was liable to undergo plastic deformation, and even when a force causing bending was generated during use, even if a force was applied, a bending habit was not easily formed. .

[0042]

As described above, the medical catheter shown in the present invention is a medical catheter having one or more lumens inside and a metal tubular member at least partially. When the metal tubular member is bent at 90 degrees with a radius of curvature of 50 times (50A) the outer diameter (A) thereof, held at 90 ° for 1 minute, and then released, the bending angle generated in the metal tubular member. Since the medical catheter is characterized in that the degree is within 15 degrees, during use, a force that causes the occurrence of bending is applied, and even when actually bent, the bending habit is unlikely to be formed, It is possible to provide an excellent catheter which is less likely to be deformed and has little operability deterioration during use.

[0043]

[Brief description of the drawings]

FIG. 1 is a schematic view showing a method for evaluating a metal tubular member of a medical catheter according to the present invention.

FIG. 2 is a schematic view illustrating a method for evaluating a metal tubular member of a medical catheter according to the present invention.

FIG. 3 is a schematic view showing a structure of a medical dilatation catheter which is an example of the present invention.

FIG. 4 is a schematic view showing a structure of a medical dilatation catheter which is an example of the present invention.

FIG. 5 is a diagram comparing an example of the present invention and a comparative example when the outer diameter of the metal tubular member is 0.70 mm.

FIG. 6 is a diagram comparing an example of the present invention and a comparative example when the outer diameter of the metal tubular member is 0.60 mm.

FIG. 7 is a diagram comparing an example of the present invention and a comparative example when the outer diameter of the metal tubular member is 1.00 mm.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Metal tubular member (outer diameter A) 2 Column of radius 50A 3 Metal tubular member (outer diameter A) 4 Bending angle 5 Expansion body 6 Synthetic resin tubular member 7 Metal tubular member 8 For guide wire Tubular member 9 Guide wire inlet port 10 Adapter 11 Adapter pressure introducing port Guide wire inlet port 13 Expansion body 14 Synthetic resin tubular member 15 Guide wire tubular member 16 Metal tubular member 17 Adapter 18 Pressure introducing port 19 Guidewire entry port

Claims (6)

[Claims] 1. A medical catheter having one or more lumens therein and a metal tubular member at least partially therein, wherein the metallic tubular member has an outer diameter (A). ), The bending angle generated in the metal tubular member when bent at 90 degrees with a radius of curvature of 50 times (50A) and held for one minute and released is within 15 degrees. . 2. A medical catheter having one or more lumens therein and a metal tubular member at least in part, wherein said metallic tubular member has an outer diameter (A). ), The bending angle generated in the metal tubular member when bent at 90 degrees with a radius of curvature of 35 times (35A) and held for 1 minute is within 30 degrees. . 3. A medical catheter having one or more lumens therein and a metal tubular member at least partially therein, wherein the metallic tubular member has an outer diameter (A). ) Wherein the bending angle generated in the metal tubular member is 35 degrees or less when bent at 90 degrees with a radius of curvature of 25 times (25A) of the above and held for 1 minute and released. . 4. The metal material of the metal tubular member includes molybdenum or titanium.
4. The medical catheter according to items 3 to 3. 5. The material of the metal tubular member is 316.
The medical catheter according to any one of claims 1 to 3, wherein the catheter is stainless steel, 321 stainless steel, or 430F stainless steel. 6. The medical catheter according to claim 1, wherein the medical catheter is a dilatation catheter intended for treatment for dilating a body passage.