JP2523405B2 - Catheter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a catheter used by being inserted into the body for the purpose of treatment, diagnosis, or other purposes of humans and other animals.

[Background technology]

Catheters are generally blood vessels (especially coronary arteries), trachea,
It is used for the purpose of injecting or inhaling a liquid or securing interstitial passages by inserting it into the fallopian tubes, ureters, or various organs.

As a catheter, a flexible catheter made of one kind of material over its entire length is widely used. This type of catheter does not pose a problem when it is inserted into a less complex part of the body, but when it is inserted into a complicated part, the overall flexibility is rather a drawback and smooth insertion is not possible. There is a problem that is difficult.

According to the research conducted by the present inventors, the end portion of the catheter on the insertion side (hereinafter referred to as a flexible portion) has excessive flexibility and elastic modulus, and the root portion (hereinafter referred to as a torque transmission portion). ) Has been found to be useful for smoothly inserting the catheter into the body, the catheter having rigidity enough to have torque transmission.

It is desirable for the catheter to have a torque transmission part because it is easy to insert until the flexible part reaches the vicinity of the target site such as a blood vessel or an organ, and the direction of travel from the vicinity of the target site to the final arrival site. When the catheter base (non-insertion part following the torque transmission part) is rotated around the axis when entering while finely adjusting, the torque transmission part has an effect of efficiently transmitting the rotational torque to the flexible part. Because it has.

On the other hand, the flexible part requires excessive flexibility when the flexible part is not flexible, such as when changing the direction or the advancing direction of the flexible part after or during the insertion of the catheter. Since the flexible part may not easily follow the desired direction or angle according to the rotation torque as the torque transmission part rotates, or the tissue of the blood vessel or organ may be damaged when the catheter is inserted. is there.

A catheter having the torque transmitting property of the torque transmitting portion and the flexibility of the flexible portion has already been proposed. For example, Japanese Patent Publication No. Sho 54-8036 discloses "a slender plastic tube for medical use" which discloses a catheter having a flexible portion and a rigid portion. Although it is necessary for the flexible portion to have flexibility for the above-mentioned reason, the known catheter described above has a flexible portion that is always flexible, for example, even before being inserted into the body. In the insertion process up to, there is a problem that smooth insertion is rather difficult because it is easily bent and caught due to friction with the insertion guide tube wall and the body tube wall. In order to ensure easy insertion, it is preferable that the flexible portion has excessive rigidity, but if the flexible portion is rigid, there is a risk of damaging the insertion site. As described above, the flexible portion is required to have the contradictory properties of flexibility and rigidity.

Therefore, the object of the present invention is easy insertion into the body,
Moreover, it is an object of the present invention to provide a novel catheter that has good torque transmission to the flexible portion after insertion and overcomes the problem of internal damage caused by the flexible portion.

[Disclosure of Invention]

In order to achieve the above object, the catheter of the present invention comprises
And a flexible portion made of a material having a glass transition temperature, which has rigidity before insertion and has flexibility after insertion, and a torque transmission portion having rigidity sufficient for torque transmission. To do.

As a result, the catheter of the present invention is easy to insert because the torque transmission part and the flexible part have appropriate rigidity before insertion, while the flexible part is heated by body temperature after insertion to increase flexibility. Therefore, the inner wall of the insertion tube is less likely to be damaged and the torque transmitted from the torque transmission portion is easily reacted.

In the present invention, the catheter means all tubular medical devices that are used by being inserted into the body for diagnosis, treatment or other purposes. That is, the catheter referred to in the present invention is composed of a single-lumen tube and has a liquid injecting / exhausting function or another catheter, a guide function such as a guide wire, or a multi-lumen tube, and has a liquid injecting / exhausting function and a temperature. Applicable to cardiovascular system, respiratory system, digestive system, urinary system, reproductive system, etc., such as those equipped with measuring function, blood pressure / blood measuring function, chemical analysis function, endoscopic function, laser fiber, balloon, etc. A wide variety depending on the area, purpose of use, and function.

The catheter of the present invention basically comprises a torque transmitting portion and the above-mentioned flexible portion having both rigidity and flexibility.
The length of the flexible part depends on the structure of the catheter and the purpose of use, but it is generally about 5 to 500 mm from the tip, and the flexible part is directly connected to the torque transmission part, or if necessary the torque via the intermediate part. It is connected to the transmission unit. The intermediate portion preferably has an elastic modulus intermediate between the torque transmitting portion and the flexible portion before, during, and after inserting the catheter into the body. The catheter having such a structure has a more gradual change in elastic modulus from the torque transmitting portion to the flexible portion, and therefore has higher performance in terms of insertability into the body, torque transmitting ability, and the like.

In the present invention, the boundaries of the above respective parts may be connected using an adhesive or may be heat-sealed. When the torque transmission part structural material and the flexible part structural material are continuously extruded by the extrusion method as described later, the component ratio of both materials gradually changes at the connecting part, and the elastic modulus also gradually changes. Change. For this reason, such a connecting portion has a preferable function as an intermediate portion.

In the catheter of the present invention, the flexible portion is composed of an organic polymer having a guide transition temperature within the body temperature of the subject to be inserted or a temperature range in the vicinity thereof. In the present invention, the glass transition temperature is a value measured in a N ₂ guide atmosphere at a temperature rising rate of 10 ° C./min by differential scanning calorimetry based on JIS K7121-1987 “Plastic transition temperature measuring method”. In addition, in this measuring method, for a material having a large number of absorption peaks of 2 or more, the lowest temperature of the absorption peaks at which sufficient flexibility is exhibited is defined as the glass transition point. For "sufficient flexibility" above, the insertion target,
The elastic modulus is generally 50 kgf / mm ² or less, preferably 10 kgf / mm ² or less, although it depends on the insertion position and the like.

In general, when many organic polymers are heated, the elastic modulus gradually decreases and the flexibility starts to increase from around a low temperature of a few dozen degrees up to the glass transition temperature. On the other hand, above the glass transition temperature and up to about ten and a few degrees higher, it is rubber-like and exhibits sufficient flexibility, but also has relatively good rigidity. At higher temperatures, it loses its rigidity and becomes too flexible. If the flexibility is excessive, the reaction to the transmitted torque becomes slow. Therefore, in the present invention, the body temperature of the insertion target is t _{0
When, (t 0 -15) ~ (} t 0 +15) ℃, preferably (t ₀
−7) to) (t ₀ +7) ° C., particularly preferably (t ₀ −5) to
It has a glass transition temperature in the range of (t ₀ +3) ° C. For example, if the subject is a human, average body temperature is 36.5 ° C
As 21.5 to 51.5 ° C, preferably 29.5 to 43.5 ° C, and particularly preferably 31.5 to 39.5.

If the material forming the flexible part has a glass transition temperature lower than (t ₀ -15) ° C, the elastic modulus becomes too small and the flexibility becomes too large due to the heating by the body temperature immediately after the insertion into the body, and the smoothness after that becomes smooth. Insertion and fine adjustment of the traveling direction due to the transmission torque are hindered. On the other hand, when the temperature is higher than (t ₀ +15) ° C, the elastic modulus does not sufficiently decrease even when heated by the body temperature, and there is a risk of damaging the tube wall in the body. Then, as the constituent material of the flexible portion, the glass transition temperature is within the above range,
And 0.01 to 50 when heated to the body temperature of the insertion target
kgf / mm ^2, preferably those specifically retain the modulus of elasticity of 0.1 to 10 / mm ^2. The entire flexible portion may be made of only one type of material, or may be made of two or more types having different elastic moduli and glass transition temperatures as exemplified in the embodiments described later. Further, at that time, it is preferable that the flexible portions are arranged so that the elastic modulus and the glass transition temperature thereof decrease stepwise or continuously as they move toward the tip. The connection between the different materials may be an adhesive or heat fusion, and as described above, the intermediate portion is provided as a preferred embodiment between the torque transmitting portion and the flexible portion. It is particularly preferred to provide an intermediate part whose composition changes continuously.

As the material forming the flexible portion of the catheter, various chemical species having the above-mentioned glass transition temperature and elastic modulus can be used. For example, polyurethanes such as ether polyurethane and ester polyurethane can be exemplified. Above all, the stoichiometrically calculated content of the hard segment portion having a weight average molecular weight of 2 × 10 ^{5 to} 7 × 10 ⁵ and consisting of diisocyanate which is a part of the polyurethane raw material and short chain glycol (here, crystal (Defined as degree of chemicalization) is 3 to 60
% By weight, or the flow start temperature measured using a rheometric viscoelasticity measuring device RMS-800 is 160 to 210.
Polyurethanes having a thermoplasticity of .degree. C. or alternatively having the above-mentioned molecular weight, crystallinity, and flow starting temperature are particularly preferable. In addition,
61-293214, Japanese Patent Application No. 63-244341, Japanese Patent Application No.
Those shown in the specification of 63-260491 and the like are also preferable.

Further, a mixed composition of the above-mentioned polyurethane and many thermoplastic organic polymers is also exemplified as the constituent material of the flexible portion. Examples of the thermoplastic organic polymer include various densities of polyethylene, polypropylene, ethylene-propylene copolymers, polyolefins such as ethylene-vinyl acetate copolymers, polyvinyl chloride, polyamides, various liquid crystal polymers, etc. To be done. Above all, liquid crystal polymer,
Liquid crystal polymer (LCP) for low temperature molding is particularly preferable. As LCP, 280 ℃ or less, preferably 150 ~ 250 ℃, especially 170 ~
Those that can be extruded in a low temperature range of about 220 ° C. are preferable. Examples of such LCP include thermotropic liquid crystal polymers such as wholly aromatic type and non-wholly aromatic type having an aliphatic component in the main chain. To be done. Of these, non-wholly aromatic thermotropic liquid crystal polymers are preferable. In commercial products,
X7G (molding temperature: 240 ℃, manufactured by Eastman Kodak Company),
Novakyurate [Made by Mitsubishi Kasei, especially Novakyurate E3
10 (molding temperature: 220 ° C)], rod run [Unitika's,
Especially Rod Run LC-3000 (molding temperature: 230 ℃)], Idemitsu LC
P (made by Idemitsu Petrochemical, especially Idemitsu LCP100E (molding temperature: 240
Degree)] and the like.

The blending ratio of polyurethane and LCP is polyurethane 100
The LCP is 5 to 120 parts by weight, preferably 10 to 100 parts by weight, and particularly preferably 20 to 60 parts by weight with respect to parts by weight.

The torque transmission part in the catheter of the present invention may have the required torque transmission property even under the body temperature of the insertion target, and may be made of a material and structure conventionally known in this field. Hereinafter, preferable embodiments of the torque transmission unit will be exemplified.

As an example, the torque transmission unit should be at least 10 degrees above body temperature.
℃, preferably at least 15 ℃, particularly preferably at least 20 ℃ higher glass transition temperature, and an elastic modulus at body temperature of at least 50 kgf / mm ² , especially at least 60 kgf / m
It is composed of a material of m ² , more particularly at least 70 kgf / mm ² . Examples of such a material include, for example, the same chemical species as the constituent material of the flexible portion, but those exhibiting the above glass transition temperature and elastic modulus are exemplified.

When the torque transmitting portion is set to a specific glass transition temperature together with the flexible portion, the degree of change in the glass transition temperature from the torque transmitting portion to the flexible portion is not limited. For example, as described in Examples below, the glass transition temperatures of the entire torque transmission portion are substantially equal, and the glass transition temperature increases from the vicinity of the boundary between the torque transmission portion and the flexible portion to the edge of the flexible portion. That decreases gradually from the edge of the torque transmitting part to the edge of the flexible part, or from the vicinity of the intermediate part of the torque transmitting part to the edge of the flexible part. The ones that gradually decrease are listed below. Further, the reduction rate of the glass transition temperature may be either stepwise or substantially continuous.

As another mode for imparting torque transmissibility to the torque transmission part, a structure in which the organic polymer layer is reinforced by coil winding or braiding of a metal wire as illustrated in FIGS. 2 to 4 is exemplified. The metal wire at that time may be a round wire, a flat wire, etc., but the flat wire is a flat shape having a size as described later, and the reinforcing portion has a size similar to that of the round wire,
In particular, the reinforcing portion of the braided structure does not become sublime and the torque transmissibility is good, which is suitable for obtaining a catheter having a small diameter and excellent torque transmissibility. Regardless of whether it is a round wire or a rectangular wire, since the sufficient torque transmissibility is provided by providing the linear metal wire in the torque transmission part, it is not necessary that the organic polymer layer itself of the torque transmission part has a high elastic modulus. Not necessarily. Rather, the action of preventing various problems (thrombus formation, damage to the inner wall of the insertion tube, elution of metal wire components, etc.) that may occur when the metal reinforcement is exposed in the body may be emphasized. . In order to prevent the metal reinforcement from being exposed, the metal reinforcement is generally provided with an organic polymer layer inside and outside thereof, but the organic polymer layer of the inner layer and / or the outer layer and the metal reinforcement are not separated from each other. As described above, the torque transmission is further improved. The inner layer is an extremely thin layer (for example, 10 to 150) that only prevents the exposure of metal wires.
However, it is preferable that the outer layer has a thickness of at least 100 μm, particularly about 200 to 1000 μm in order to prevent unevenness of the metal reinforcement (which may cause thrombus formation) from appearing.

The rectangular wire is not particularly limited as long as it imparts torque transmissibility to the torque transmission part and is harmless to the human body, but has an elastic modulus of 7,000 kgf / mm ² in order to impart excessive flexibility to the torque transmission part.
More preferably, it is particularly preferably 10,000 kgf / mm ² or more.
The flat wire may be a stainless wire, a piano wire, a tungsten wire, a nickel-titanium alloy wire or the like formed into a flat shape by rolling or the like, and the flat metal wire of the above-mentioned metal wire may be further processed by rolling or the like to have a small cross section. For example, a molded product may be used.

Also, the aspect ratio (ratio of line width to thickness) as a rectangular wire is 1.5 to 20, especially 2 to 15, and the line width is (d / 5) to (d / 50) where the outer diameter of the metal reinforcement is d. , Especially (d / 7) ~ (d /
40) is preferable.

When coiling or braiding a metal wire, particularly a rectangular wire, the inclination angle (acute angle) of each metal wire with respect to the central axis of the catheter is 20 to 80 °, preferably 30 to 60 °, particularly 40.
~ 55 ° is preferred. Regarding the linear density of the rectangular wire in the metal reinforcement, 1 m of the circumference (that is, length πd) of the metal reinforcement
The number of fibers per m is preferably 0.1 to 20, especially about 0.5 to 10.

In the above, the cross-sectional structure of one rectangular wire,
The dimensions and the method of use have been described, but one flat wire is cut into two or more pieces, preferably from 2 to 10, in the longitudinal direction, in other words, two or more flat wire pieces are arranged side by side in a bundle (a bundle). The flat material may have the same aspect ratio and line width as the one rectangular wire described above). In the case of such a bundle, the torque transmitting portion obtained as compared with the case of using one rectangular wire is excellent in flexibility while maintaining good torque transmitting property.

The torque transmission part using the above-described flat wire (or flat thin wire bundle) is useful as a torque transmission tube regardless of the presence or absence of the flexible part.

One of the preferred embodiments is a torque transmission part having a structure in which the above-mentioned rectangular wire is reinforced on the organic polymer tube obtained by extrusion molding, particularly braided reinforcement, and the organic polymer coating is applied on it. is there. In this case, the coating applied on the rectangular wire reinforcement is preferably made as thin as possible in order to keep the outer diameter of the catheter small, and it is desirable to use a paint that can be applied to it. Examples of such coating materials include vinyl chloride resin, polyethylene, paint type polyurethane, silicone rubber, fluororesin, and the like, but paint type polyurethane is most suitable.

As still another example of the torque transmission part, there is a mode in which a temperature adjusting mechanism is provided inside the organic polymer tube, which is a structural element of the torque transmission part, to maintain the elastic modulus required for torque transmission. This example will be described in detail with reference to FIG.

The above is the rigidity and flexibility of the flexible portion and the torque transmissibility of the torque transmission portion. Other requirements for the catheter include easiness of direction change at the time of insertion and easy operation after completion of insertion. It is preferable to have a property. If the catheter is as thin as possible, it can penetrate into the details of the body, but it should be large enough to fully perform the functions such as injecting / inhaling the liquid after the insertion, local expansion, and securing patency. Will be needed. On the other hand, the flexible portion of the catheter has various shapes (for example, a curved shape and a hook shape) so that the catheter can be turned according to the application area and easily reach the target site. The straight shape is not only easier to insert, but also less likely to damage the cell tissue in the body.

From this point of view, it is preferable to store a predetermined shape in the catheter in accordance with the application and application area, and maintain the entire catheter straight before insertion and restore it to the memory shape during insertion. For example, the flexible portion of the catheter is deformed and restored from a small diameter to a large diameter at body temperature, and at least the flexible portion is deformed and restored to a memorized shape (curved shape or hook shape) at body temperature. . This shape memory material may be the material of the flexible part of the preceding example, among which the good crystallinity of shape memory property is 30 to 50% by weight, and the flow initiation temperature of good workability is 170 to 190 ° C. Polyurethane,
Alternatively, a mixed composition of various polyurethanes and LCP is most suitable.

As is clear from the above, the catheter having the specific glass transition temperature of the present invention has sufficient flexibility in the flexible portion due to body temperature, and the catheter having the shape memorized is restored to the memorized shape by body temperature. Therefore, the catheter may be provided with a temperature adjusting mechanism for preventing the catheter from being affected by the body temperature until the catheter reaches a predetermined portion. For this purpose, for example, a cooling circulating water channel may be provided in the torque transmitting portion of the catheter in addition to the original holes for various functions, and the catheter may be cooled by passing water through the channel during the insertion operation. Alternatively, in addition to simply cooling, for example, a water channel is provided up to the flexible portion, and the flexible portion is cooled or warmed with warm water as necessary to give the flexible portion any rigidity or flexibility, It is also possible to restore the memory shape of the part.

On the other hand, the flexible portion of the catheter may be shielded from X-rays so that an X-ray contrast image can be obtained when the catheter is used while confirming the current position under fluoroscopy. This includes barium sulfate (BaSO
₄ ) is mixed with the flexible part that becomes the X-ray contrast part, a gold or platinum ring or filament is attached to the flexible part, and a polymer composition containing gold powder is applied to the flexible part. Good. However, in order to further enhance the shielding effect and obtain a clear X-ray contrast image, the flexible portion corresponding to the X-ray contrast portion should contain an inorganic material having a specific gravity of 5 or more, particularly 8 or more. Is preferred.

In this case, the inorganic material having a specific gravity of 8 or more is not particularly limited as long as it can be applied to the human body for a catheter, and gold, silver, platinum, tungsten, barium,
Lead, tantalum, molybdenum, bismuth, iridium or their oxides (bismuth tungstate, barium tungstate, bismuth subcarbonate, bismuth oxide, etc.),
Carbides, nitrides, borides, etc. are exemplified.

Further, the thickness of the catheter is not particularly limited in the present invention, and various modes may be adopted depending on the application area, function, and the like. For example, one having a uniform diameter from the torque transmitting portion to the flexible portion, one tapering from the torque transmitting portion to the flexible portion, one having a constant diameter torque transmitting portion and a flexible portion, It is shown that only a portion of about 1 to 5 mm from the edge has a small diameter.

The cross-sectional structure of the catheter is also not limited, and there are single lumen and multi-lumen. The multi-lumen includes one in which functional equipment (for example, image guide, light guide, flash channel, laser fiber, etc.) is inserted into each hole after insertion into the body, and one in which those equipment are inserted in advance before insertion into the body.

The various aspects of the material and structure of the catheter have been described above. An example of a method of manufacturing a catheter made of these materials and structures will be described below.

Although there are various methods of manufacturing a catheter in which the torque transmitting portion has rigidity and the flexible portion has appropriate rigidity and flexibility, the torque transmitting portion having normal rigidity and the flexible portion having appropriate flexibility are separately provided. After manufacturing, the torque transmission part and the flexible part are joined by an adhesive or heat fusion, or the organic polymer composition that is the material of the catheter is formed into a small diameter by extrusion molding, and then the There is a method in which post-processing is performed on a portion corresponding to the flexible portion and a portion corresponding to the torque transmitting portion to give necessary flexibility and rigidity. There is also a manufacturing method described in Canadian Patent No. 093071, which is an improved manufacturing method. In the manufacturing method, a first plastic material having a predetermined physical characteristic (mainly flexibility etc.), which serves as a flexible portion so as to eliminate the need for a post-treatment step, is inserted into the first extruder to form a predetermined torque serving portion. A second plastic material having physical properties (mainly rigidity) is inserted into the second extruder, first the material in the first extruder is extruded, and then the material of the flexible part is placed at regular intervals. The catheter is extruded by decreasing the flow rate from the first extruder and at the same time increasing the flow rate from the second extruder containing the material of the torque transmitting portion in a proportional manner. Further, in a method in which the block of the member forming the torque transmitting portion and the block of the member forming the flexible portion are inserted into one extruding device, and the flexible member and the torque transmitting member are sequentially melt extruded from the extruding device. Good.

Among these manufacturing methods, the manufacturing method is particularly preferable as the manufacturing method of the catheter of the present invention because it can manufacture a catheter with few structural and characteristic defects. This manufacturing method does not perform extrusion molding by gradually increasing and decreasing the flexible member and the torque transmission member by using two extruders as in the manufacturing method, and does not include the flexible member and the torque transmission member in one extruder.
As will be described later with reference to FIGS. 9 and 9, they are in contact with each other but are inserted in a completely separated state, and are extruded in that order.

The catheter of the present invention is characterized in that the flexible portion has rigidity enough to satisfy the ease of insertion before insertion, and exhibits flexibility due to body temperature after insertion. Therefore, in practical use, the catheter has a circulatory system (coronary artery). Etc.), respiratory system, digestive system, urinary system, reproductive system, sensory system, spinal column / joint, and other applicable areas, as well as those with functions and structures according to the purpose of use such as treatment and diagnosis. Good.

For example, a shape memory catheter in which the flexible portion has the specific glass transition temperature or elastic modulus and the entire catheter is deformed from a small diameter to a large diameter after insertion is used. Does not impair the various functions of.
In particular, those in which only the flexible portion is restored to a large diameter are suitable for urological and reproductive systems. In the urinary system, when inserting a catheter of a thickness usually used in the ureter and a tubule leading to it, it was often accompanied by severe pain each time the catheter contacted the ureter. When the thin catheter is used, since the flexible portion has a small diameter during insertion, it hardly touches the ureter and can be easily inserted into a desired portion without feeling any pain. When pulling out the catheter, it is already warmed by body temperature and becomes flexible, and when pulling out the catheter, there is no need to rub the tube wall with the corner of the tip, so it is especially painful even if the flexible part is restored to a large diameter. Such problems do not occur. With the genital organs, it is possible to take measures to prevent the uterus from rupturing.

A shape memory catheter that restores to a memory shape (curved shape, hook shape, etc.) is particularly suitable for use in a heart blood vessel, an abdominal blood vessel, and a cerebral blood vessel. In this case, since the predetermined direction is automatically changed by restoring the memory shape, it is possible to easily perform the operation of changing the traveling direction and the entire insertion operation.

[Brief description of drawings]

1 (a) to 1 (f) are schematic plan views showing various aspects of the catheter of the present invention in which specific glass transition temperatures are set in the flexible portion and the torque transmission portion, and the length and glass transition temperature of each catheter. It is a graph which shows a change degree.

FIG. 2 is a partially omitted schematic view of a catheter in which a rectangular wire is braided on a torque transmission portion.

FIG. 3 is a vertical cross-sectional view of the torque transmission portion in the catheter shown in FIG.

FIG. 4 is a partially omitted schematic view of a catheter in which a rectangular wire is wound around a torque transmitting portion.

5 (a) to 5 (c) show an embodiment of a catheter in which the shape of the flexible portion is stored, FIG. 5 (a) is a partially omitted external view showing the state before the deformation and restoration thereof, and FIG. 3A is a partially omitted external view showing a state of being deformed and restored to a memorized shape, and FIG. 3C is a partially omitted external view showing a state of being deformed and restored from a small diameter to a large diameter at body temperature.

FIG. 6 is a partially omitted external view of a catheter in which a flexible portion has X-ray contrast property.

7 (a) and 7 (b) show a catheter in which a temperature adjusting mechanism is provided in the torque transmitting portion, FIG. 7 (a) is a vertical sectional view with a part thereof omitted, and FIG. 7 (b) is a transverse sectional view of the torque transmitting portion. .

FIG. 8 is a schematic explanatory view showing an example of a manufacturing method in the catheter of the present invention based on the manufacturing method.

FIG. 9 is a schematic explanatory view showing another example of the manufacturing method in the catheter of the present invention based on the manufacturing method.

[Best mode for carrying out the invention]

Hereinafter, the catheter of the present invention will be described in detail based on examples.

Since the shape of the entire catheter in which the flexible portion has a predetermined glass transition temperature may be a conventionally known one, here, the case where both the flexible portion and the torque transmitting portion have a specific glass transition temperature is taken as an example, and the torque transmission is performed. A description will be given focusing on aspects of various degrees of change in the glass transition temperature from the flexible portion to the flexible portion.

FIGS. 1 (a) to 1 (f) are graphs showing various catheters and changes in the glass transition temperature (T _g ) of each catheter. The catheter shown in (a) consists of three parts a ₁ , a ₂ , a ₃ having different T _g's . In the catheter, a ₁ corresponds to a torque transmitting portion, a ₃ corresponds to a flexible portion, and a ₂ is an intermediate portion in which both constituent materials are mixed. T _{g of} this catheter
The degree of change, as shown in the right graph, a ₁ is a constant value, a ₃
There a constant value less than a _1, a ₂ decreases gradually in accordance leading to a ₃ from a _1. Of course, a ₁ as above shows the T _g and modulus extent sufficient to torque transmissibility, a ₃ illustrates the T _g and modulus as tinged with flexible at body temperature after insertion.

The catheter shown in (b) is composed of three parts (torque transmitting part, intermediate part, flexible part) b ₁ , b ₂ , b ₃ each having different T _g as in (a), but b ₃ As can be seen from the graph on the right showing the change, the T _g of gradually decreases almost continuously.

Catheter (c) it is, c ₁ corresponding to the torque transmitting portion is constant T _g, T _g of the flexible portion c ₃ to c ₅ is configured to decrease stepwise. c ₂ is the torque transmission part c ₁ and the flexible part c ₃
And c ₄ is an intermediate portion between the portions c ₃ and c ₅ in the flexible portion.

In the catheter of (d), the degree of decrease in T _g is made substantially continuous and slow, the torque transmitting portion corresponds to d ₁ to d ₃ , the flexible portion corresponds to d ₅ to d ₇ , and d ₄ is It forms an intermediate part between the torque transmission part and the flexible part. In this catheter, the T _{g of the} torque transmission part is different stepwise between d ₁ and d ₃ with the middle part d ₂ as the boundary, and the T _{g of} the flexible part is also d ₅ with the middle part d ₆ as the boundary. And d ₇ differ stepwise.

The catheter (e) has a structure in which the rectangular portion of the torque transmitting portion e ₁ is braided, and has a constant T _g , and the flexible portion e ₂ has a continuously decreasing T _g .

In (f), a rectangular wire is wound around the torque transmitting portion f ₁ , and T _g of the flexible portions f _{2 to} f ₄ is gradually reduced as in the example (c).

The catheter 11 shown in FIGS. 2 and 3 corresponds to the example (e) of the embodiment shown in FIG. 1 and includes a torque transmitting portion 12 and a flexible portion.
The torque transmission portion 12 is formed by braiding a tube 14 of an organic polymer material having the same or different glass transition temperature as the flexible portion 13 and a rectangular wire 15 provided on the tube 14, for example. It comprises a metal reinforcement 16 and a resin coating 17 applied on the metal reinforcement 16. As shown in FIG. 2, the resin coating 17 extends beyond the tip of the metal reinforcing member 16 and reaches the flexible portion 13.

The catheter 21 shown in FIG. 4 is the embodiment example (f) of FIG.
In the torque transmission part 22, the flat wire 25 is coiled at a constant pitch on a tube 24 similar to the tube 14 used in the embodiment of FIG. It is wound so as to intersect with each other in two mutually opposite directions of about 54 ° with respect to the axis, and is similarly coated with a resin coating 27.

The catheter 31 of the embodiment shown in FIG.
The predetermined shape is stored in. Of course, it goes without saying that the torque transmitting portion 32 retains the torque transmitting property even when it is warmed by the body temperature, and the flexible portion has rigidity before insertion and appropriate flexibility after insertion. FIG. 5 (b) shows a state in which the flexible portion 33 of the catheter of FIG. 5 (a) has been deformed and restored to the hook-shaped memory shape at body temperature.

When the catheter 31 is inserted into a blood vessel, an organ or the like, the flexible portion 33 still has an appropriate rigidity without being sufficiently warmed by the body temperature, so that the flexible portion 33 can be easily inserted up to the direction changing portion during the insertion. is there. When reaching the direction changing portion, the torque transmitting part 32 still retains sufficient torque transmitting property, but the flexible part 33 is sufficiently warmed by the body temperature, has flexibility, and is stored in advance. The original shape can be restored to the original angle and direction, and the direction of the flexible portion 33 can be changed easily.
The catheter 31 can be easily inserted to the final insertion site.

The catheter 31 shown in FIG. 5 (c) has the shape shown in FIG. 5 (a) before insertion, but has a flexible portion after insertion into the body.
In order that the outer diameter of the memorized shape of the end edge portion 33 ′ of 33 becomes larger than the outer diameter of the memorized shape of the portion other than the end edge portion 33 ′, the memorized outer diameter of the end edge portion 33 ′ of other portions is previously set. It is set slightly larger than the outer diameter of memory. Before heating the body temperature, the catheter shown in (c) has a small diameter and is substantially equal in diameter including the large-diameter memory portion of the end edge portion 33 '. In the catheter 31 of such a mode, only the end edge portion 33 'is deformed and restored to a large diameter, so that it can be used as a preventive measure against rupture of the urinary organ and uterus.

The catheter 31 shown in FIGS. 5 (b) and 5 (c) is first formed into a linear shape by an extrusion molding method or the like using the respective materials forming the torque transmitting portion 32 and the flexible portion 33, and then the flexible material is formed. Only the flexible part is heated to a high temperature near the agglomeration temperature of the hard segment of its constituent material to give the desired deformation (memory shape), and cooled to a low temperature slightly above the glass transition temperature while maintaining the deformation. , Then brought straight again at that temperature and cooled at room temperature.

FIG. 6 shows a catheter provided with an X-ray contrast property. The present catheter 41 includes a torque transmitting portion 42, a flexible portion 43, and an X-ray contrasting edge portion 44. The edge portion 44 contains an inorganic material having a high specific gravity as described above, and a sufficient X-ray contrast image can be obtained. The X-ray contrast agent is preferably contained in the entire flexible portion 43 and torque transmitting portion 42.

A catheter 51 shown in FIGS. 7 (a) and 7 (b) is provided with a temperature adjusting mechanism inside. In the torque transmission part 52, in order to keep the torque transmission part 52 at a constant temperature, a cooling circulation water passage 57 is provided separately from a passage 55 for performing various functions as a catheter. Water is passed through the water channel 57 during the insertion operation of the catheter 51 to constantly cool the torque transmitting portion 52 so that the torque transmitting portion 52 is not heated by the body temperature.

Next, a more detailed example of the method for producing the catheter of the present invention by the above production method will be described.

FIG. 8 shows a case where only one catheter is extruded. In the cylinder 100, a block 1 of a low glass transition temperature organic polymer (hereinafter referred to as a flexible member) that constitutes a flexible portion and a high glass transition temperature organic polymer (hereinafter referred to as torque) that constitutes a torque transmission portion. (Referred to as a transmission member), the cylinder 100 is maintained at a high temperature to sufficiently heat and melt the blocks 1 and 2, and then a plunger 102 provided on one side of the cylinder 100 is used to insert both materials 1 and 2. Are sequentially extruded from the small-diameter mouth 101 to manufacture one small-diameter catheter.

FIG. 9 shows a case where n catheters are continuously extruded at one time. In the cylinder 200, blocks 1 _a , 1 _b , ..., 1 _m , 1 _{n of} flexible members corresponding to n pieces and blocks 2 _a , 2 _b , ..., 2 _{m of} torque transmission members, insert a 2 _n alternately, similarly plunger 202 provided on one side of the cylinder 200
Both materials are sequentially extruded from the small diameter port 201 by
Manufactures a small diameter catheter. It is then cut from the appropriate sections and separated into individual catheters, with each catheter further cut to the desired length if necessary.

Hereinafter, some examples of the present invention using specific materials and comparative examples will be shown to clarify the remarkable effect of the present invention. Table 1 shows the materials used in the examples and comparative examples and their characteristics.

Examples 1 to 5 and Comparative Example 1 A single lumen catheter having the structure and dimensions shown in Table 2 was prepared. Each catheter has a total length of 150 cm, and both the flexible section and the torque transmission section have an inner diameter of 1.40 mm and an outer diameter of 2.35.
mm.

All of Examples 1 to 4 are two or more kinds selected from the materials shown in Table 1 and melt-extruded at an extrusion temperature of 185 ° C. by the method shown in FIG. 8, and different materials are melt-bonded. Assuming that there is an intermediate part where the materials are gradually mixed with each other over an average of 3 cm, but there is no intermediate part in Table 2 (that is, half the length of each intermediate part, An average of 1.5 cm is listed as belonging to either). Further, in the same table, when two or more kinds of materials are used, the closer to the tip of the flexible portion of the catheter, the higher the description.

Example 5 is a braid made of SUS304 flat wire having a thickness of 25 μm and a wire width of 110 μm (outer diameter: 1.95 mm, inner diameter: 1.8 mm, the number of flat wire existing on the circumference: 16, each flat wire We made a tube for material-B torque transmission part in which a tilt angle of 45 degrees with respect to the central axis of the catheter, length: 130 cm) was embedded in the center of the thickness, while a tube for flexible part consisting of only material-B was prepared. Separately, it was produced by extrusion, and then both (both outer diameter: 2.35 mm, inner diameter: 1.40 mm) were heat-sealed together.

Comparative Example 1 is a tube made of only Material-B over the entire length of 150 cm.

The torque transmissibility of each catheter was measured by the following method. Table 2 shows the results.

Torque transmissibility: long straight part length is 122 cm, short straight part length is 10 cm, radius of curvature is about 5 cm, total length is 140 cm,
Place a U-shaped tube made of SUS with an inner diameter of 3 mm on the desk, insert each catheter into it, and make the tip of the flexible part of the catheter project 1 to 2 mm from the outlet of the short straight part, and then insert it with the U-shaped tube While filling the space between the catheter and the saline at 36.5 ° C, the entire chamber was kept at 36.5 ° C. After leaving for about 5 minutes in this state, when a 180 degree twist is given to the root of the torque transmission part of the catheter protruding from the end of the long straight part of the U-shaped tube, the rotation angle appearing at the tip of the flexible part It was measured.

The following is an example showing the effect of the metal reinforcing body in the present invention.

As a tube, MD Kasei's polyurethane (trade name:
Peresen 2363 ・ 55DE, Shore D hardness: 55) only outer diameter: 2.65 mm, inner diameter: 1.65 mm (tube 1), the same polyurethane tube used for tube 1, but outer diameter: 60 μm Braided SUS304 round wire (outer diameter:
2.3mm, inner diameter: 2.0mm, number of round wires on the circumference: 16
Angle of each book and each round wire with respect to the central axis of the catheter: 45
(Tube 2), and a braid (outer diameter: 2.2m) made of SUS304 rectangular wire with a thickness of 25 μm and a wire width of 110 μm instead of the round wire of the tube 2 (tube 2)
m, inner diameter: 2.1 mm, number of rectangular wire on the circumference: 16
Angle of inclination of each rectangular wire with respect to the catheter central axis: 45
(Tube 3) was manufactured by incorporating the degree (degree) therein.

The transverse elastic modulus (torsion, kgf / mm ² ) and longitudinal elastic modulus (bending, kgf / mm ² ) of each tube are 10, 10 for tube 1 and 20, 40 for tube 2, respectively.
For tube 3 it was 30, 30 respectively. From this, the tube having the metal reinforcement is generally excellent in elastic modulus, and the tube 3 using the rectangular wire is superior in the lateral elastic modulus as compared with the tube 2 using the round wire, and thus the torque transmission is further improved. It can be seen that the elastic modulus is slightly small and the suppleness is excellent while having the properties.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaiho, 8 Nishinomachi, Higashimukaijima, Amagasaki City, Hyogo Prefecture Mitsubishi Cable Industries, Ltd. (72) Kazuo Onishi, 8 Nishinomachi, Higashimukaijima, Amagasaki City, Hyogo Kogyo Co., Ltd. (72) Inventor Shunichi Hayashi 1-1016 Nishinodai, Chita City, Aichi Prefecture (56) References JP-A-2-57271 (JP, A) JP-A-59-67959 (JP, A)

Claims (6)

(57) [Claims] 1. A torque transmission part having a rigidity sufficient for torque transmission, and a flexible part made of a material having a glass transition temperature which has rigidity before insertion and has flexibility after insertion. A catheter provided with. 2. The glass transition temperature of the flexible portion is from (t ₀ -15) to
The catheter according to claim 1, wherein the temperature is (t ₀ +15) ° C (where t ₀ is body temperature). 3. The catheter according to claim 1, wherein the flexible portion is made of polyurethane. 4. The torque transmitting portion is at least 10 ° C. above the body temperature.
The catheter according to claim 1, which is made of a material having a high glass transition temperature. 5. The catheter according to claim 1, wherein the torque transmitting portion is composed of an organic polymer layer and a metal reinforcing body. 6. The catheter according to claim 5, wherein the metal reinforcement is a braid of rectangular wires.