JP2005334542A - Medical tube and its joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical tube and its joining method capable of strengthening enough a joint strength between tubes when the tubes are joined together, making the joint part a smooth surface without partially changing the rigidity of the tubes, and suppressing deterioration and deformation of the tube surface. <P>SOLUTION: This medical tube 10 has one tube 20 whose outer diameter is reduced at the end and the other tube 30 whose inner diameter is increased at the end, and the one end of the tube 20 is inserted into the other end of the tube 30, and the joint part C of both tubes is welded and joined. For more detail, an electrically-conductive core metal 140 is inserted in at least the inner periphery of the joint part C of the both tubes, and an electrically-conductive mold frame 120 is arranged on the outer periphery of the joint part C to sandwich the joint part C of the both tubes, high frequency voltage is applied between the core metal 140 and the mold frame 120, and the joint surface of the both tubes is welded and joined by dielectric heating. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medical tube that is used by being inserted into a tubular organ of a human body such as a blood vessel and formed by joining two or more tubes, and a joining method thereof.

  Insert a medical tube and administer contrast agents, etc., or force a part of tissue through forceps etc. for inspection and treatment of human organs such as blood vessels, ureters, bile ducts, and trachea It is being collected. This medical tube may be used by joining a plurality of tubes depending on the application or purpose.

  In the following Patent Document 1, the end surfaces of the tube of the catheter main body and the tube of the distal end portion are butted on a metal member provided so that the outer diameter of the core rod matches, and the outer surface of the tube is placed on the end surface butting portion. A metal ring with an inner diameter that matches the diameter is fitted, and the metal member attached to the core bar and the metal ring are heated by electrical induction, and the end face butting portion of the tube is heated from inside and outside and heat-sealed while shaping. A method for manufacturing a catheter is disclosed.

In Patent Document 2 below, the torque tube of the catheter body that is passed through the core rod and the distal end tube that is joined and extended to the distal end of the distal end tube are expanded in a trumpet shape. Formed on the inside of the trumpet-shaped part of the tip tube in front of the end face of the torque part tube in the method of covering the top part of the torque part tube and heating and integrating the superposed part while applying pressure from the outer surface. An annular member made of the same material as the tip tube is arranged in the inner space of the joint, and the annular member is placed on the end surface of the torque portion tube and the inner surface of the trumpet portion of the tip tube during the heating. A method for manufacturing a catheter is disclosed, wherein the inner seam is smoothly finished by heat fusion integration.
JP-A-5-337187 JP-A-5-329214

  In the method in which the end surfaces of the tubes are brought into contact with each other as in the joining method of Patent Document 1, the contact area is extremely large because only the thickness of the tube is in contact with each other. In many cases, the bonding strength was insufficient.

  Moreover, in the manufacturing method of the catheter of the said patent document 2, the part which overlapped and became thick is heated from each surface of the outer periphery and inner periphery of a tube, and the edge parts of a tube are surface-contacted and joined. The melted part (hereinafter simply referred to as a joint) is joined. However, since the overlapped part becomes a double wall, it is difficult to smooth the outer periphery, and the outer diameter can be partially thickened, or the tube can be deformed if forcibly smoothed. There was sex.

  In addition, the joint portion that is overlapped and thickened is likely to be harder than other portions, and the rigidity of the tube may be locally changed. For this reason, there is a problem in the flexibility of the tube, which may be difficult to insert when inserted into a bent blood vessel.

  Furthermore, if the joints that are overlapped to form a double wall are sufficiently heated and melted, the tube surface will be heated more than necessary, which tends to cause deterioration and deformation, and the deformation will leave it in the blood vessel. When doing so, there is a possibility that it may become resistance or hinder the injection of a chemical solution such as an anticancer drug.

  Accordingly, an object of the present invention is to sufficiently increase the bonding strength between the tubes when the tubes are bonded to each other, and to make both the outer diameter and inner diameter of the bonded portion a smooth surface. Another object of the present invention is to provide a medical tube and a method for joining the same, which can prevent the tube stiffness from being locally changed and does not deteriorate or deform the tube surface.

  In order to achieve the above object, the first of the present invention is a medical tube formed by joining two or more tubes made of a thermoplastic resin, one tube having a reduced outer diameter of an end portion, And having the other tube with an enlarged inner diameter at the end, inserting the end of the one tube into the end of the other tube, and welding and joining the joints of both tubes A medical tube characterized by the above is provided.

  According to the first aspect of the invention, the end of one tube whose outer diameter is reduced and the end of the other tube whose inner diameter is increased are joined in a state of being in contact with each other. As compared with the case where the end faces of the tubes are joined to each other as in the conventional case, the joining strength between the tubes can be sufficiently increased.

  In addition, the thickness of the joint where the end of one tube whose outer diameter is reduced and the end of the other tube whose inner diameter is increased is compared with the thickness of the tube other than the joint Even so, it is almost unchanged. Therefore, the joining portion of the tube can be made a smooth surface without causing a step on the outer diameter side or the inner diameter side. Moreover, since the joint is not thick, the rigidity of the tube does not change locally.

  Also, when the welded part of the tube is heat-welded, the thickness of the overlapped joined part is relatively thin, so that it is easy to heat-weld and the tube surface is not deteriorated or deformed. Workability can also be improved.

  According to a second aspect of the present invention, in the first aspect, the tube has a dielectric loss ε · tanδ (ε: dielectric constant, tanδ: dielectric power factor) of 0.012 or more at an applied frequency of 1 MHz and a temperature of 20 ° C. Thus, a medical tube made of a material of 0.7 or less is provided.

  According to the second aspect of the invention, when the dielectric heating described above is performed, the tube efficiently generates heat, so that a medical tube that can be easily joined with little deterioration and deformation of the tube surface is obtained. .

  According to the third aspect of the present invention, the end of one tube whose outer diameter is reduced is inserted into the end of the other tube whose inner diameter is increased, so that at least the inner circumference of the joint portion of both tubes is reached. A conductive metal core is inserted, a conductive mold is disposed on the outer periphery of the joint, the joint between both tubes is sandwiched, and a high frequency is provided between the conductive core and the conductive mold. The present invention provides a method for joining medical tubes, characterized by applying a voltage and welding the joining surfaces of both tubes by dielectric heating.

  According to the third aspect of the invention, since the end portion of one tube whose outer diameter is reduced is inserted into the end portion of the other tube whose inner diameter is increased, the contact area between the end portions of the respective tubes is increased. Can be secured.

  In that state, a conductive metal core is inserted into the inner periphery of the joint portion of both tubes, a conductive mold is placed on the outer periphery of the joint portion, and the joint portion of both tubes is sandwiched between the core metal and the mold frame. By applying a high-frequency voltage between them, the tubes can be joined with a wide contact area, and the joining strength of the joined portion of the tubes can be further increased.

  In addition, since the thickness of the joint and the thickness of the tube other than the joint are almost the same, heat welding is facilitated, and a step is created between the outer diameter side and the inner diameter side of the tube joint. Therefore, the surface can be smooth and the rigidity of the tube can be prevented from changing locally.

  Furthermore, since the tube material itself generates heat as a characteristic of the dielectric heating due to the dielectric heating, the contact surface is less than in the case of heating from the outside of the tube joint as in Patent Documents 1 and 2. Since it is heated efficiently and uniformly and rapidly heat-welded, the workability of the joining work is greatly improved.

  According to a fourth aspect of the present invention, in the third aspect, the tube has a dielectric loss ε · tanδ (ε: dielectric constant, tanδ: dielectric power factor) of 0.012 or more at an applied frequency of 1 MHz and a temperature of 20 ° C. Thus, the present invention provides a method for joining medical tubes made of a material of 0.7 or less.

  According to the fourth aspect of the invention, when the dielectric heating described above is performed, the tube efficiently generates heat, so that the tube surface is less deteriorated and deformed and can be easily joined. .

  According to the medical tube and the joining method thereof of the present invention, the joining strength between the tubes can be increased, and the joined portion of the tube is smooth without causing a step on the outer diameter side or the inner diameter side. And the tube stiffness can be kept from changing locally. Moreover, since the thickness of the overlapped joining portion is relatively thin, it is easy to heat-weld and the tube surface is not deteriorated or deformed. Furthermore, since the tube itself generates heat from the inside by dielectric heating, heat welding is performed uniformly and quickly, so that the workability of the joining work is greatly improved.

  Hereinafter, with reference to FIGS. 1-3, one Embodiment about the medical tube and its joining method of this invention is described.

  FIG. 1 (a) shows tubes 20 and 30 to be joined used in the medical tube 10 (hereinafter referred to as the tube 10) of the present invention. Referring also to FIG. 1B, the end of one tube 20 is formed with a tapered outer diameter, that is, a tapered portion 21 that gradually tapers along the tube end. The end portion of the other tube 30 is formed with a tapered portion 31 whose inner diameter is increased, that is, a tapered portion 31 whose diameter is gradually increased along the tube end portion.

  As the material of the tubes 20 and 30, the dielectric loss ε · tan δ (ε: dielectric constant, tan δ: dielectric power factor) at an applied frequency of 1 MHz and a temperature of 20 ° C. is 0.012 or more and 0.7 or less. It is preferable to use synthetic resins having a dipole in the molecule such as polyurethane, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyester, polyamide, and copolymers thereof, which easily generate heat when dielectrically heated. It is done. According to this, since a tube generates heat efficiently, it can join easily. Note that an olefin-based resin material such as polyethylene that does not have a dipole in the molecule is not preferable because it usually hardly generates heat alone.

  Further, when forming the tapered portion 21, the tube itself is rotated and ground with a file, a cutting tool, or other grinding tools, or the tube is pressed against a mold heated above the softening point of the material, or It is formed in advance by molding means such as injection molding. On the other hand, when forming the tapered portion 31, using an electric tool that rotates a bit portion at the tip called a router (also called a router), insert the bit portion into the tube end portion and grind, or It is formed in advance by molding means such as injection molding.

  Then, the tube 20 and the tube 30 are welded by the tube joining device in a state where the end of the tube 20 is inserted into the end of the tube 30 and the tapered portions 21 and 31 are in contact with each other. Become. FIG. 2 shows a tube joining apparatus 100 used in this case.

  The base 110 shown in the figure is formed of an insulating material. On the upper surface of the base 110, a lower mold 121 of a mold 120 made of an upper and lower mold is disposed. On the other hand, the upper mold 122 of the mold 120 is fixed to the electrode 130. The electrode 130 is provided with an air cylinder or the like (not shown) and can be moved up and down. Then, the electrode 130 and the upper mold 122 are normally arranged at positions separated from the lower mold 121, and when the tubes are joined, they are lowered to bring the upper mold 122 and the lower mold 121 into contact with each other.

  The mold 120 is made of a metal material such as Al, an Al alloy, an Fe alloy, or a Cu—Zn alloy, for example. Among these, Cu—Zn alloys having good conductivity are preferably used.

  Also, semicircular cutouts 121a and 122a are provided at the upper center of the lower mold 121 and the lower center of the upper mold 122, respectively, so that the upper mold 122 and the lower mold 121 are in contact with each other. Sometimes it has a circular shape. The circular inner diameter is set to be slightly smaller than the outer diameter of the tube 30. When the upper and lower molds 122 and 121 are closed, the tube junction C is pressed by the inner periphery of the notches 122a and 121a. It has come to be.

  Further, a conductive metal core 140 to be inserted into the tubes 20 and 30 is disposed. The core metal 140 is formed with an outer diameter that is slightly smaller than the inner diameter of the tubes 20 and 30. Further, as shown in FIG. 3A, the cored bar 140 may have a shape in which a diameter-enlarged portion 141 is provided at the tip. According to the core bar provided with this enlarged diameter portion, it is possible to efficiently generate heat at the inner periphery of the joint portion C of the tube.

  One end of the lead wire 150 is connected to one end of the cored bar 140. In the middle of the lead wire 150, a high-frequency voltage generation source 160 is connected. Further, the other end of the lead wire 150 is connected to the electrode 130 and is electrically connected to the upper mold 122.

  Using such a tube joining apparatus 100, the tube 20 and the tube 30 are joined as follows.

  First, the tubes 20 and 30 formed with the tapered portions 21 and 31 shown in FIG. 1A are inserted into the ends of the tubes 30 as shown in FIG. The taper portions 21 and 31 are brought into contact with each other. Thus, since the taper parts 21 and 31 contact, the contact area of the edge parts of the tubes 20 and 30 can be ensured large.

  Then, the cored bar 140 is inserted into the tube as shown in FIG. In this case, the distal end portion of the cored bar 140 is inserted to at least a position reaching the inner periphery of the joint portion of both the tubes 20 and 30.

  Next, the joint portion C of the tube in which the core metal 140 is inserted is placed in a semicircular cutout 121 a provided in the lower mold 121 of the tube joining device 100. And the air cylinder provided in the electrode 130 is operated, the upper mold | type 122 is lowered | hung, and the upper mold | type 122 and the lower mold | type 121 are contact | abutted. Thus, since the conductive metal core 140 is inserted into the inner periphery of the joint portion C of both tubes and the outer periphery of the joint portion C is pressed by the conductive mold 120, the joint portion C of the tube is the outer periphery and the inner portion. It will be pressed from the circumference.

  Then, the high frequency voltage generated by the high frequency voltage generation source 160 on the lead wire 150 is applied between the cored bar 140 and the upper mold 122 and the lower mold 121 in a state where the joint C is pressed. Then, the joint portion C of the tube is dielectrically heated and melted by the high-frequency voltage, and is welded while being pressed between the cored bar 140 and the mold 120, so that the joint portion C of the tube is joined, as shown in FIG. The tube 10 shown in b) is formed.

  Thus, since the end of one tube 20 whose outer diameter is reduced and the end of the other tube 30 whose inner diameter is increased are joined to each other while being in contact with each other, a large contact area is ensured. The joining strength between the tubes can be sufficiently increased as compared with the case where the joining is performed in a state where the end faces of the tubes are brought into contact with each other as in the related art.

  In addition, the thickness of the joint portion C in which the end portion of one tube 20 whose outer diameter is reduced and the end portion of the other tube 30 whose inner diameter is enlarged is overlapped is that of the tube other than the joint portion C. Compared to the wall thickness, it is almost unchanged. For this reason, the joint C of the tube does not cause a step on both the outer diameter side and the inner diameter side, and can be made a smooth surface, so that it can be easily inserted into a thin blood vessel, etc. The guide wire is not caught on the inside of the tube. Moreover, since the joint portion C is not thick, the rigidity of the tube does not change locally, and it becomes easy to insert even in a bent blood vessel.

  Furthermore, since the tube material itself generates heat as a characteristic of dielectric heating due to dielectric heating, the contact surface is heated more efficiently and uniformly compared to the case where the joint C of the tube is heated from the outside. Moreover, since heat welding is performed quickly, the workability of the joining work is greatly improved.

  In addition, since the thickness of the overlapped joint portion C does not increase, heat welding is performed smoothly, and the tube surface is not deteriorated or deformed. Therefore, it does not become a resistance when the tube is placed in the blood vessel, and does not obstruct the injection of a chemical solution such as an anticancer drug.

  The medical tube joining method of the present invention can be applied to joining existing tubes and tubes of various shapes.

  For example, the present invention can be applied to a medical tube in which a metal tube or a resin wire is alternately intersected and formed by embedding and reinforcing a so-called braided material as a main body, and a flexible tube is joined to the tube. In this medical tube, the tube body is reinforced to ensure torque transmission and pushability, and the tube tip is made flexible so that the inner wall of the tubular organ is not damaged.

  Moreover, it is applicable also to the medical tube which joined the flexible tube main body and the tube front-end | tip part shape | molded so that a coil etc. may be arrange | positioned in an inner periphery and it may press-contact with the blood vessel inner wall. This medical tube is firmly fixed to the inner wall of the blood vessel by the distal end of the tube, and a medical solution such as an anticancer drug is injected.

  In addition, as a tube for inject | pouring a chemical | medical solution, you may use the medical tube of the shape shown by FIG. This figure shows this medical tube and its joining method.

  In this medical tube, the distal end surface of one tube 30 is closed by a distal end wall 32 made of an elastic material. The distal end wall 32 has a thin central portion, and a hole or notch (not shown) is formed in the thin portion. The hole or notch is normally closed, and is elastically opened when the guide wire is pressed from both the inside and outside directions so that the guide wire can be inserted. Moreover, the peripheral edge of the tip wall 32 forms the tip of the tube 20.

  One tube 30 at this time is formed by dipping or injection molding, and the other tube 20 joined thereto is formed by extrusion molding. As described above, one tube 30 may be shaped so as to be pressed against the inner wall of the blood vessel.

  According to the present invention, the one tube 30 having the tip wall 32 formed by injection molding or the like as described above and the other tube 20 formed by extrusion molding or the like are joined with a high bonding strength. can do.

  When the drug solution is injected into the medical tube shown in FIG. 4, the hole or notch formed in the distal end wall 32 of the tube 20 is elastically expanded by the pressure of the drug solution, and the drug solution is injected into the target location. After the injection of the chemical solution, the distal end wall 32 is elastically restored and closed to prevent the backflow of blood into the tube.

  In addition, since the guide wire can be inserted from the distal end side and the rear end side of the tube, the guide wire can be inserted into the blood vessel first, and the tube can be inserted along the guide wire. Even when it is desired to correct the position, it is possible to correct the position by inserting a guide wire from the rear end side of the tube.

  FIG. 5 shows another example of the medical tube 10 and its joining method according to the present invention. The tubes 20a and 30a used here are different in end shape from the tubes 20 and 30 described above. That is, as shown in FIG. 5 (a), a diameter-reducing step portion 21a having a constant diameter is provided at the end of the tube 20a. On the other hand, the end portion of the tube 30a is provided with an enlarged diameter step portion 31a having an enlarged diameter. Then, the end portion of the tube 20a is inserted into the end portion of the tube 30a, the reduced diameter step portion 21a and the enlarged diameter step portion 31a are placed in contact with each other, and the cored bar 140 is inserted. The medical tube 10 shown in FIG. 5B can be formed by applying a high-frequency voltage and dielectrically heating the joint C in a state where the joint C is pressed, and joining the joint C.

Example A plurality of tubes having the shape shown in FIG. 1 were prepared and joined together.

  First, tubes 20 and 30 having an outer diameter of 1.7 mm and an inner diameter of 1.0 mm were molded using polyurethane by a tube extrusion molding machine.

  Then, while rotating one of the tubes, the file was pressed to form the tapered portion 21, and the tube 20 was obtained.

  Further, a heated metal tapered mandrel was inserted into the end of the other tube and rotated to form a tapered portion 31, thereby obtaining a tube 30.

  And the edge part of the tube 20 was inserted in the edge part of the tube 30, and the taper parts 21 and 31 were made to contact. The outer diameter of the joint C at this time was 1.75 mm.

  Next, a cored bar 140 having an outer diameter of 1.0 mm was inserted into the tube.

  3 is placed in the notch 121a of the lower mold 121 of the bonding apparatus 100 shown in FIG. 3, the air cylinder is operated, the upper mold 122 is lowered, and the lower mold 121 is brought into contact therewith. It was. The inner diameter of the notch 121a was 1.7 mm.

  In addition, one end of the lead wire was connected to the cored bar 140 and the other end was connected to the electrode 130 to be electrically connected to the upper mold 122. A high-frequency voltage generation source 160 is connected in the middle of the lead wire.

  In this state, a high frequency voltage having an applied frequency of 40.46 MHz and an output of 250 W was applied from the high frequency voltage generation source 160. Then, the joined portion C of the tube was heated and melted, and the medical tube 10 in which the tube 20 and the tube 30 were joined was obtained.

  When the both ends of the medical tube 10 thus obtained were pulled, it was confirmed that they were firmly joined. Moreover, although visually confirmed, deterioration and deformation | transformation of the tube surface were not confirmed but the smooth surface was obtained.

Test Example Tubes joined by various methods were pulled by a tensile tester, and the joint strength of the joint C was measured. Samples are as follows.

Sample 1
Sample 1 was obtained by joining the joints C of the tubes 20 and 30 produced in the above example by heat welding by dielectric heating.

Sample 2
Sample 2 was obtained by joining the joints C of the tubes 20 and 30 produced in the above example by blowing hot air from the outside and heat-welding them.

Sample 3
By adding a small amount of tetrahydrofuran (THF) as a solvent to the tapered portion 21 of the tube 20 produced in the above embodiment to dissolve the surface, and then inserting it into the tapered portion 31 of the tube 30 and leaving it for several hours. Sample 3 was obtained by welding the joint C.

Sample 4
In the above embodiment, the end surfaces of the tubes not subjected to taper processing are abutted with each other while being cut and formed by the extrusion molding machine, and the joining portion C is joined by heating and welding by dielectric heating to obtain a sample 4. It was.

Sample 5
In the above-described embodiment, the end faces of the tubes that have not been subjected to the taper processing are abutted with each other while being cut and formed by the extrusion molding machine, and hot air is blown from the outside of the joint C to heat and weld the joint C. The sample 5 was obtained by bonding.

Sample 6
In the above-described embodiment, a small amount of tetrahydrofuran (THF) as a solvent is dropped on one end surface of a tube that has not been subjected to taper processing while being cut by an extrusion molding machine, and then the surface is melted. The joints C were welded by abutting each other and allowed to stand for several hours to obtain a sample 6.

  Samples 1 to 6 as described above were sandwiched between chucks so that the joint C was in the center, and in that state, the sample was pulled at a speed of 500 mm / min to measure the load when the joint C was broken. . This test was performed three times for each sample, and the results are shown in Table 1. In addition, the appearance of the joint C of Samples 1 to 6 was evaluated in four stages (◎ ··· Good, ○ ··· Normal, Δ ··· Bad, × ·· Very bad), and the results are also shown in Table 1. Indicated.

  As shown in Table 1, it can be seen that Samples 1 to 3 in which both ends are tapered are higher in bonding strength than Samples 4 to 6 in which the joining portion C is abutted and joined. In particular, Sample 1 that was tapered and joined by dielectric heating had less variation for each measurement and stable and high joint strength compared to Sample 3 that was tapered and joined by solvent welding. .

  Moreover, since it was necessary to press the joining part C and the samples 4-6 which are joined to the longitudinal direction of a tube, deformation | transformation was remarkable and the external appearance of the joining part C was bad. On the other hand, the joints C of the samples 1 to 3 subjected to the taper processing have a relatively good appearance, and in particular, the appearance of the joint C of the sample 1 subjected to the taper processing and bonded by dielectric heating is the best among the samples. It can be understood that the combined use of the taper processing and the dielectric heating has a very good effect.

  In the present invention, when joining tubes, the joining strength between the tubes can be made sufficiently high, and both the outer diameter and inner diameter of the joined portion can be made a smooth surface. It can be used as a medical tube and its joining method that can maintain the rigidity of the tube uniformly at any location and does not deteriorate or deform the tube surface.

1 shows one embodiment of a medical tube and a joining method thereof according to the present invention, (a) is a perspective view showing a state before joining one tube and the other tube, and (b) shows one tube and It is sectional drawing which shows the state before joining the other tube. It is a perspective view which shows the joining apparatus used when joining the medical tube. 1 shows an embodiment of the medical tube and its joining method, (a) is a schematic diagram showing a state when one tube and the other tube are joined, and (b) shows a joint between both tubes. It is sectional drawing which shows the state which formed the medical tube. It is sectional drawing which shows an example of the tube joined by the medical tube and its joining method. The other example of the medical tube and its joining method is shown, (a) is a sectional view showing the state before joining one tube and the other tube, (b) is joining both tubes. It is sectional drawing which shows the state which formed the medical tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Medical tube 20, 30 Tube 120 Formwork 140 Core metal C Joint part

Claims (4)

In a medical tube formed by joining two or more tubes made of thermoplastic resin,
Having one tube with a reduced outer diameter of the end and the other tube with an enlarged inner diameter of the end, inserting the end of the one tube into the end of the other tube, A medical tube characterized in that the joint portion of both tubes is welded and joined.   2. The tube is made of a material having a dielectric loss ε · tan δ (ε: dielectric constant, tan δ: dielectric power factor) at an applied frequency of 1 MHz and a temperature of 20 ° C. of 0.012 or more and 0.7 or less. The medical tube described.   Insert the end of one tube with the reduced outer diameter into the end of the other tube with the expanded inner diameter, and insert a conductive core metal so that it reaches at least the inner circumference of the joint of both tubes. The conductive mold is disposed on the outer periphery of the joint, the joint between both tubes is sandwiched, a high-frequency voltage is applied between the core metal and the mold, and the joint surface of both tubes is heated by dielectric heating. A method for joining medical tubes, characterized by welding and joining.   4. The tube is made of a material having a dielectric loss ε · tan δ (ε: dielectric constant, tan δ: dielectric power factor) at an applied frequency of 1 MHz and a temperature of 20 ° C. of 0.012 or more and 0.7 or less. The medical tube joining method as described.

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