JP2000254232A - Catheter and indwelling needle assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter and an indwelling needle assembly excellent in an anti-kink property, a flexibility and a breakage resistant property with a sharp blade edge of an inner needle without causing a bending at a curved and bent position of a blood tube while maintaining a flexibility ensuring a followability at the same position. SOLUTION: An inner layer and an outer layer having a flexibility are connected through a reinforcing material 5 comprising a linear body 51 made of thermoplastic resin. When the number of a linear body in one rotation direction is n and the number of a linear body in the other rotation direction is m, the linear body 51 is formed to a structure such that the number S of an organization point during the time when all of the linear bodies rotate in one rotation is represented by n×m>S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indwelling needle and an indwelling needle assembly applied to an indwelling needle used for indwelling an artery and a vein such as an infusion solution.

[0002]

2. Description of the Related Art When performing infusion or the like on a patient, an indwelling needle assembly composed of an indwelling needle (outer needle) and an inner needle is used. This indwelling needle assembly has a double needle structure in which the inner needle is inserted into the outer needle and integrated, and only the inner needle is removed after the arteriovenous puncture, leaving only the outer needle in the living body. Is what you do. For this reason, the outer needle body needs to have appropriate flexibility in order to ensure the followability of the curved or bent portion of the blood vessel, and a catheter made of a flexible material such as various elastomers is used.

However, since the inner needle is made of a metal material such as stainless steel and has a sharp cutting edge (needle tip) formed at its tip, the inner needle is sharpened when the inner needle is inserted into or removed from the catheter. A sharp edge may cause the catheter to be damaged such as cut, scratched, scraped, cracked, broken, peeled, or broken. In particular, it is not preferable that such breakage of the catheter occurs during indwelling of a living body. Further, the catheter needs to be as flexible and thin as possible in order to bend the blood vessel, to prevent kink from bending at the bent portion, and to reduce the damage to the blood vessel.
Therefore, flexibility, kink resistance and breakage resistance are all required.

As described above, in order to prevent a part of the catheter from remaining in the body in the event of breakage, a plurality of helical linear bodies that rotate clockwise and counterclockwise are alternately arranged inside the catheter. Although catheters arranged in a lattice so as to overlap one another have been devised, they are not preferred in terms of flexibility.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a catheter which is thin, has a smooth surface, and is excellent in cutting resistance and kink resistance, and an indwelling needle assembly using the same.

[0006]

The above object is achieved by the present invention described below. (1) The present invention provides a catheter in which a flexible inner layer and an outer layer are joined via a reinforcing material, and the reinforcing material is formed of a linear body made of a thermoplastic resin. The reinforcing material is formed by combining a plurality of the linear bodies formed into a spiral of a clockwise rotation and a counterclockwise rotation, and the linear bodies in one rotation direction are n pieces, and the linear bodies in the other rotation direction are n. When the number of the linear bodies is m, the number S of the tissue points during the rotation of all the linear bodies by one rotation is represented by n × m> S.

(2) In the present invention, the number of the linear bodies is n ≧
3. The catheter according to (1), wherein m ≧ 3. (3) The present invention is the cartel according to (1) or (2), wherein the number of the linear bodies is n = m. (4) The present invention is the catheter according to any one of (1) to (3), wherein the number S of tissue points during one rotation of the linear body is represented by n × m> 1.5 × S. . (5) The present invention is the catheter according to any one of (1) to (4), wherein the thermoplastic resin is a polyamide-based or polyester-based resin.

(6) The present invention is the catheter according to any one of (1) to (5), wherein the inner layer and the outer layer are thermoplastic elastomers. (7) The present invention is the catheter according to any one of (1) to (6), wherein the inner layer and the outer layer are a thermoplastic polyurethane elastomer. (8) The present invention provides an indwelling needle assembly comprising an indwelling needle comprising the catheter according to any one of the above (1) to (7), and an inner needle inserted inside the catheter. is there.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a catheter and an indwelling needle assembly according to the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings. FIG. 1 is a plan view showing an overall configuration example of the indwelling needle assembly of the present invention. FIG. 2 is a partially cutaway view of a catheter 2 used for the indwelling needle 1 of the indwelling needle assembly shown in FIG. FIG. 3 is an enlarged longitudinal sectional view. In FIGS. 1 and 2, the radial direction of the catheter 2 is schematically shown in a particularly enlarged manner for easy understanding.

[0010] The indwelling needle 1 shown in FIG.
The catheter 2 includes a catheter hub 8 attached to a proximal end 21 of the catheter 2, and a caulking pin 7 for caulking the proximal end 21 to the catheter hub 8. As shown in FIG. 2, the catheter 2 has a lumen 3 formed therein from the base end 21 to the distal end. This lumen 3
Is a channel for a chemical solution or the like. The indwelling needle 1 is inserted into a blood vessel while the inner needle body 91 of the inner needle 9 is inserted into the lumen 3 and the catheter hub 8 is fitted to the inner needle hub 10. By puncturing the skin and blood vessels. In addition, the catheter hub 8 functions as an injection port for a drug solution or the like into the lumen 3 and also functions as a grip when operating the indwelling needle 1.

As shown in FIG. 2, the inner layer 4 and the outer layer 6 of the catheter 2 are joined via a reinforcing member 5. The inner layer 4 and the outer layer 6 are each made of a material having flexibility (flexibility). Specifically, for example, polyolefin such as polypropylene, polyethylene, and ethylene-vinyl acetate copolymer, polyamide, and polyethylene terephthalate, respectively. , Such as polyester, polyurethane such as polybutylene phthalate, polyurethane, polyvinyl chloride, polystyrene resin, fluorine resin such as ethylene-tetrafluoroethylene copolymer, polyamide elastomer, polyester elastomer, polyurethane elastomer, polystyrene elastomer, fluorine elastomer, etc. Elastomers or a combination of two or more thereof can be used.

Of these constituent materials, polyurethane elastomers are particularly desirable from the viewpoints of antithrombotic properties, kink resistance, economy and the like. Here, a polyurethane elastomer is a polymer alloy (polymer blend, graft polymerization, random polymerization, etc.) with another resin having high flexibility.
It is a concept that also includes those softened with a plasticizer or the like, and also a mixture thereof. The constituent materials of the inner layer 4 and the outer layer 6 may be the same or different. When the constituent materials of the inner layer 4 and the outer layer 6 are the same or different,
The hardness of the material used for the outer layer 6 is 30 Shore D hardness.
It is desirably about 80.

In the illustrated configuration, the inner diameter and the outer diameter of the inner layer 4 and the outer layer 6 are respectively constant, but they may vary along the longitudinal direction of the catheter 2. For example, a configuration in which the inner diameter of the inner layer 4 gradually increases in the distal direction may be employed.

The reinforcing member 5 is constituted by a linear body 51. Here, the configuration of the reinforcing member 5 will be described in detail with reference to FIGS. The reinforcing material 5 includes a plurality of linear members 5
1 is wound around the outer periphery of the inner layer in a clockwise and counterclockwise spiral to form a lattice. At this time, when the number of linear bodies in one rotation direction is n and the number of linear bodies in the other rotation direction is m, the number S of tissue points during which all the linear bodies make one rotation is n × They are formed in a lattice shape as represented by m> S. In the illustrated configuration, the linear member 5 of the catheter 2 is
1 uses eight linear bodies in one rotation direction and eight linear bodies in the other rotation direction, and all the linear bodies are 1
The tissue points are formed in a lattice shape such that the number S of the tissue points during the rotation is 32. FIG. 4 shows an enlarged view of one form of the lattice when the number S of the tissue points is 32. That is, one linear body 51a in one rotation direction floats on two continuous linear bodies 51b in the other rotation direction, and two continuous linear bodies 51b in the other rotation direction are connected. Submerging alternately is repeated, and a linear body adjacent to the linear body 51a in the same rotational direction is shifted by one by one with respect to the linear body in the other rotational direction and repeats a similar form. .

The tissue point refers to a portion where a linear body in one rotational direction continuously floats and sinks in the other linear body in the rotational direction.

The present invention is not limited to this.
May be formed in a lattice shape so as to be 16. Further, in the illustrated example, the reinforcing member 5 is provided over the entire length of the catheter 2, but the present invention is not limited to such a configuration, and the reinforcing member 5 is provided at a portion other than the distal end portion 22. There may be.

In the illustrated example, one type of linear body 51 is used.
However, the present invention is not limited to such a configuration, and may be combined using two or more types of linear bodies.

As a constituent material of the linear body 51 forming the reinforcing member 5, any material may be used as long as it has sufficient rigidity to obtain sufficient breakage resistance and kink resistance. For example, it is preferable that the catheter 22 has thermoplasticity that can be melted at the time of thermal processing of the distal end portion 22, such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).
Polyester, polyethylene, polyolefin such as polypropylene, rigid polyvinyl chloride, polyamide, polyimide, polystyrene, thermoplastic polyurethane, polycarbonate, ABS resin, acrylic resin, polymethyl methacrylate (PMMA), polyacetal (PA), polyarylate , Polyoxymethylene (PO
M), high tensile strength polyvinyl alcohol, fluororesin, polyvinylidene fluoride (PVdF), polytetrafluoroethylene, ethylene-vinyl acetate saponified (EVOH),
Examples thereof include polysulfone, polyether sulfone, polyether ketone, polyphenylene oxide, polyphenylene sulfide, a polymer alloy containing any of these, or a combination of two or more of these. Further, a mixture of these and a contrast material may be used.

Among these constituent materials, polyamide is particularly desirable because it has a certain heat shrinkability at a temperature lower than the melting point of the inner layer. Here, polyamide refers to, for example, nylon 6, nylon 64, nylon 66, nylon 610,
Nylon 612, Nylon 46, Nylon 9, Nylon 11, Nylon 12, N-alkoxymethyl modified nylon, Hexamethylenediamine-isophthalic acid condensation polymer,
Representative examples include various aliphatic or aromatic polyamides such as metaxyloyldiamine-adipic acid condensate, and polymer alloys of the polyamide and other resins (polymer blend, graft polymerization, random polymerization, etc.), Furthermore, the concept includes these mixtures.

The linear body 51 is made of a single fiber or an aggregate of fibers (for example, a single fiber twisted) made of the above-mentioned material or the like.
However, a single fiber is desirable from the viewpoint of the post-processability of the distal end portion 22 of the catheter. Further, the single fiber may be a conjugate fiber, and examples thereof include a conjugate fiber made of the above-described constituent material and the contrast-enhancing material. In addition, the linear body 5
The thickness of 1 is such that a necessary and sufficient reinforcing effect and flexibility can be obtained in relation to its constituent material, and the post-processing of the distal end of the catheter is easy. In the case of using fibers, the diameter is 20 to 5
It is desirable to set it to about 0 μm. In addition, the linear body 51 is
It may be used singly or in a state of being bundled.

The linear body 51 is formed into a tapered shape at the distal end portion 22 of the catheter by heat treatment, or is formed into a trumpet shape by heat treatment at the base end portion 21 of the catheter to fit a pin. For example, it is preferable to melt or soften at the same time as the catheter 2. Actually, if the difference between the melting or softening temperature of the linear body 51 and the catheter 2 is within 60 ° C., the processing is easy, and if the difference is within 30 ° C., the processing becomes even easier.

Next, a preferred example of the method for producing a catheter of the present invention will be described. First, the inner layer 4 is formed according to a standard method. Next, the linear body 51 is wound around the outer peripheral surface of the inner layer 4 such that the linear body 51a in one rotation direction always intersects with the two linear bodies 51b in the other rotation direction to form a lattice shape. . This winding method uses, for example, a device (not shown) called a braider, and feeds out the linear body 51 while rotating the linear body supply portion around the outer periphery of the inner layer 4 both left and right around the inner layer 4, At the same time, the inner layer 4 is moved in the axial direction, and the linear body 51 is continuously wound around the outer peripheral surface of the inner layer 4.

At this time, the linear body 51 is continuously wound at a constant angle (θ) and pitch with respect to the axial direction of the catheter 2. The pitch interval may vary within a predetermined range depending on the portion of the catheter 2. The angle (θ) is desirably 15 to 65 degrees, and the pitch is desirably 1 to 7 mm.

After the reinforcing material 5 is formed on the outer peripheral surface of the inner layer 4 as described above, the outer periphery is covered with the outer layer 6. The outer layer 6 is joined such that the inner peripheral surface of the outer layer 6 is in close contact with the outer peripheral surface of the inner layer 4 and the linear body 51.
For example, a method of bonding with an adhesive or a solvent, the inner layer 4
A method of fusing with the like (for example, heat fusing, high-frequency fusing), a method of inserting the inner layer 4 by swelling the outer layer 6 by heating or a solvent and then shrinking the same, and a method of shrinking the molten outer layer material or liquefied outer layer material. A method of forming the outer layer 6 by applying it and solidifying it by cooling or desolvation treatment may be mentioned, and a method of applying the molten outer layer material and solidifying it by cooling to form the outer layer 6 is used. The process is simple and is a common method in the industrial field.

In the outer layer forming method, before the molten outer layer material is applied, the surface of the reinforcing material 5 is appropriately preheated, and then the molten outer layer material is applied, and the outer layer 6 is solidified by cooling. It is desirable to form. According to the manufacturing method as described above, the catheter 2 has a small thickness, excellent cut resistance and kink resistance, and a flexible catheter 2 can be obtained.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a catheter 2 of an indwelling needle assembly according to the present invention will be described.
A specific example will be described. FIG. 2 showing the conditions in each embodiment.
The catheter having the configuration shown in FIG. 3 was manufactured by the method described above. In addition, the linear body was wound using a braider driven by an electric motor to produce the reinforcing material.

In this winding method, the wire 51 is fed out from the wire feeder of the braider, and the wire is fed while rotating the wire feeder around the outer periphery of the inner layer 4 right and left around the inner layer 4. The inner layer 4 is moved in the axial direction together with the linear body 51 so that the linear body 51
Continuously wound. Thus, the catheter 2 is continuously wound at a constant angle (θ) and a constant pitch with respect to the axial direction of the catheter 2. Thus, the linear bodies 51 intersect with each other, and a tissue point is formed by a combination of the linear bodies 51.
At the time of this winding, by appropriately setting the intersection timing of the linear body supply unit, the linear body 5 in one rotation direction can be set.
The number of intersections of the portion where 1a intersects the linear body 51b in the other rotation direction, that is, the number of tissue points is determined. Further, the number of linear bodies between the pitches, that is, the density of each linear body is determined by the number of linear bodies set in advance and the moving speed of the inner layer 4 in the axial direction.

In the outer layer forming method, before the molten outer layer material is applied, the surface of the reinforcing material 5 is preheated at 160 ° C., and the linear body 51 is appropriately heated. And solidified by cooling to form the outer layer 6.

When the surface of the reinforcing member 5 is heated, if the material used in each embodiment is a heating temperature of 180 ° C., the temperature is too high, and a part of the linear body 51 is melted. In addition, the reinforcing effect of the reinforcing material 5 is almost lost. When the heating temperature is 1
When the temperature is 00 ° C., the temperature is too low and the linear body 51 is not heated much, so that the adhesion between the inner layer and the outer layer is low.

Example 1 A catheter 2 having the following conditions was manufactured by the above-described method. Overall length of catheter 2: 32 mm Outer diameter of outer layer 6: 0.86 mm Outer diameter of inner layer 4: 0.75 mm Inner layer 4: 0.64 mm Constituent material of outer layer 6: thermoplastic polyurethane elastomer (Shore D hardness: 67, melting point) : 170 ° C) Constituent material of inner layer 4: Same as outer layer 6 Constituent material of linear body 51: Diameter of single fiber linear body 51 of polyamide (nylon 6, melting point: 210 ° C): 41 µm All linear bodies make one turn Number of organization points during the operation: 32 (FIG. 4
(Indicated by (1)) The inclination angle (θ) of the linear body 51 with respect to the axial direction of the catheter 2: 30 degrees The number of the linear bodies 51: 8 clockwise rotations, 8 counterclockwise rotations, a total of 16
Book

(Test Example) In order to examine the kink resistance of the obtained catheter 2, the catheter 2 was set at a curvature of 5 mm to 9
The catheter 2 was inspected for bending when bent repeatedly 50 times at 0 degrees. Further, the load at break when the catheter 2 was pulled straight in the axial direction at a speed of 300 mm / min was measured. Further, both ends of the catheter 2 were pinched with fingers of both hands, and both hands were brought to the center to form a loop. The results are shown in Table 1 below. Regarding the flexibility, those produced in each of the examples and comparative examples were relatively evaluated (the most excellent one was indicated by ◎, the most excellent one was indicated by 、, and the most inferior one was indicated by x). The measurement was performed at room temperature (20 ° C.).

[0032]

[Table 1]

(Embodiment 2) The number of the linear bodies 51 is rotated right by 6
A catheter 2 similar to that of Example 1 was prepared except that the number of the catheters and the number of left rotations were six, and a total of twelve catheters were prepared.

[0034]

[Table 2]

(Example 3) A catheter 2 was prepared in the same manner as in Example 1 except that the number of tissue points during the rotation of the linear body 51 by one rotation was set to 16, and the same measurement as in the above test example was performed. The results are shown in Table 3 below.

[0036]

[Table 3]

(Comparative Example 1) A catheter similar to that of Example 1 was prepared except that the linear member 51 was not provided, and the same measurement as in the above Test Example was performed. The results are shown in Table 4 below.

[0038]

[Table 4]

(Comparative Example 2) A catheter similar to that of Example 1 was prepared except that the number of tissue points during the entire rotation of the linear body was made one, and the same measurement as in the above-mentioned test example was performed. Are shown in Table 5 below.

[0040]

[Table 5]

(Results) As described above, the catheter used for the indwelling needle of the present invention shown in each of the examples shows excellent effects in all of the frequency of occurrence of breakage, resistance to breakage (breakage), and flexibility as compared with the comparative example. Was. In addition, the same test was performed on the catheter of the present invention under the same conditions as those of the examples except that the inclination angle of the linear body 51 with respect to the axial direction of the catheter 2 and the number of the linear bodies 51 were changed. The same excellent effects as in the example were exhibited.

[0042]

As described above, according to the catheter of the present invention and the indwelling needle assembly using the same as the indwelling needle, the catheter has a sufficient breaking strength by the reinforcing material, so that the catheter has high breakage resistance. It exhibits excellent kink resistance and followability, and further exhibits high flexibility. As a result, it is possible to prevent accidents such as cutting and bending of the catheter and to reduce vascular damage.

That is, the present invention relates to a catheter in which an inner layer and an outer layer are joined via a reinforcing material, wherein the reinforcing material is composed of a linear body, and one linear body in one rotational direction is n and the other is a linear body. When the number of linear bodies in the rotation direction is m, by forming them in a lattice shape such that the number S of the tissue points while all of the linear bodies make one rotation is represented by n × m> S, Excellent kink resistance and breakage resistance can be obtained while maintaining flexibility. For this reason, it has kink resistance and flexibility that does not cause bending at the curved and bent portions of the blood vessel, while ensuring followability at the bent portions.

The indwelling needle assembly using the catheter of the present invention as an indwelling needle has the above-described effect of the catheter, and further, when the inner needle body is inserted into the lumen of the catheter, the catheter is damaged by the sharp cutting edge. Can be used without.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration example of an indwelling needle assembly of the present invention.

FIG. 2 is a partially cutaway sectional view showing the internal structure of the catheter 2 of the indwelling needle shown in FIG.

FIG. 3 is a perspective view showing a configuration of a reinforcing member in the catheter 2 of the indwelling needle shown in FIG. 1;

FIG. 4 is an enlarged view showing an example of a structure of a linear body in a reinforcing member of the catheter 2 of the indwelling needle shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 indwelling needle 2 catheter 21 proximal end 22 distal end 3 lumen 4 inner layer 5 reinforcing material 51 linear body 51a linear body 51b in one rotational direction 51b linear body in the other rotational direction 6 outer layer 7 caulking pin 8 catheter hub 9 inner needle 91 inner needle body 92 cutting edge (needle point) 10 inner needle hub

Claims (8)

[Claims] 1. A catheter in which a flexible inner layer and an outer layer are joined via a reinforcing material, and the reinforcing material is formed by a linear body made of a thermoplastic resin. The material is formed by combining a plurality of the above-mentioned linear bodies that are formed into a right-handed and left-handed spiral, and the n-shaped linear bodies in one rotation direction and the linear bodies in the other rotation direction are formed. When the number of bodies is m, the linear bodies are all 1
A catheter, wherein the number S of tissue points during rotation is represented by n × m> S. 2. The catheter according to claim 1, wherein the number of the linear bodies is n ≧ 3 and m ≧ 3. 3. The apparatus according to claim 1, wherein the number of said linear bodies is n = m.
3. The cartel according to any one of claims 1 to 2. 4. The catheter according to claim 1, wherein the number S of tissue points during one rotation of the linear body is represented by n × m> 1.5 × S. 5. The catheter according to claim 1, wherein the thermoplastic resin is a polyamide or polyester resin. 6. The catheter according to claim 1, wherein the inner layer and the outer layer are thermoplastic elastomers. 7. The catheter according to claim 1, wherein the inner layer and the outer layer are thermoplastic polyurethane elastomers. 8. An indwelling needle assembly comprising an indwelling needle comprising the catheter according to any one of claims 1 to 7, and an inner needle inserted inside the catheter.