catheter

Abstract

A catheter capable of firmly fixing a shaft and a tube seat is provided. The catheter (10) comprises: a shaft (20) which is a tube body, the tube body is formed with a tube lumen (21) connected from the front end to the base end, the shaft (20) has a shaft base end surface (24) for opening the tube lumen (21) and a shaft outer surface (22) as the outer peripheral surface of the tube body; and a tube seat (40) mounted on the base end of the shaft (20), the tube seat (40) having a cylindrical receiving portion (41) for receiving the shaft (20), the receiving portion (41) having a tube seat welding surface (49) directly welded to the shaft outer surface (22), and at least one of the receiving portion (41) and the tube seat (40) has a plurality of bubbles formed at a position close to the tube seat welding surface (49).

Description

Technical Field

[0001] The present invention relates to a catheter Background Art

[0002] In recent years, treatment within the lumen of a blood vessel or the like using a catheter has become popular because of the extremely low surgical invasion. The catheter generally has a shaft and a tube seat, the shaft having a lumen connected from the front end to the base end, and the tube seat is arranged at the base end of the shaft. The tube seat has a passage connected to the lumen in order to connect to a syringe or the like.

[0003] As a method of fixing the base end of the shaft and the socket, an insert molding method, a bonding method using an adhesive, and the like are known.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-180802

[0007] Patent Document 2: Japanese Utility Model Publication No. 63-17486 Summary of the invention

[0008] The insert molding method described in Patent Document 1 is to place a shaft in an injection mold, press a portion of the shaft with a fixing pin, and perform injection molding of a resin for a tube socket at a high temperature and high pressure. Therefore, the shaft may be deformed and offset in the axial direction due to the fixing pin. The deformation of the shaft and the offset in the axial direction may reduce the fixing strength between the shaft and the tube socket.

[0009] In addition, in the bonding method using the adhesive described in Patent Document 2, if the gap between the outer diameter of the shaft and the inner cavity of the shaft receiving portion of the tube seat is too small, the adhesive cannot flow in, leaving a gap between the tube seat and the shaft, which may reduce the fixing strength between the shaft and the tube seat. If the gap between the outer diameter of the shaft and the inner cavity of the shaft receiving portion of the tube seat is too large, it is difficult to completely fill the gap between the tube seat and the shaft with the adhesive, which may reduce the fixing strength between the shaft and the tube seat.

[0010] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a catheter capable of firmly fixing a shaft and a tube seat.

[0011] The catheter of the present invention for achieving the above-mentioned purpose comprises: a shaft which is a tube body, the tube body being formed with a lumen connected from the front end to the base end, the shaft having a shaft base end surface for opening the lumen and a shaft outer surface which is the outer peripheral surface of the tube body; and a tube seat mounted on the base end of the shaft, wherein the catheter is characterized in that the tube seat has a cylindrical housing portion for housing the shaft, the housing portion having a tube seat welding surface which is directly welded to the shaft outer surface, and at least one of the housing portion and the tube seat has a plurality of bubbles formed at a position close to the tube seat welding surface.

[0012] Effects of the Invention

[0013] The conduit configured as described above is welded by the air bubble so that the housing portion and the tube seat are fitted into each other. Therefore, the shaft and the tube seat can be firmly fixed.

[0014] Alternatively, the receiving portion may be provided with a plurality of tube seat bubbles at a position close to the tube seat welding surface. Thus, the tube seat welding surface of the receiving portion has a complex shape with projections and depressions and is welded to the outer surface of the shaft. Therefore, the shaft and the tube seat can be firmly fixed.

[0015] Alternatively, the shaft may have a plurality of shaft bubbles formed thereon at a position close to the shaft welding surface of the shaft outer surface welded to the tube seat welding surface. Thus, the shaft outer surface has a complex shape with concave and convex shapes and is welded to the tube seat welding surface. Therefore, the shaft and the tube seat can be firmly fixed.

[0016] Alternatively, the tube seat and the shaft may both have a plurality of bubbles, and the tube seat welding surface and the shaft welding surface of the shaft outer surface welded to the tube seat welding surface may be welded to each other in a manner of having projections and depressions and fitting into each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a top view showing the catheter according to the embodiment.

[0018] Figure 2 It is a cross-sectional view showing the base end portion of the pipe seat and the shaft.

[0019] Figure 3 It is a cross-sectional view showing the front end portion of the pipe seat and the base end portion of the shaft.

[0020] Figure 4 It is a cross-sectional view showing the front end portion of the pipe seat before the shaft is fixed.

[0021] Figure 5 The diagram is a top view showing the process of welding a shaft and a pipe seat, wherein (A) shows the state at the beginning of welding and (B) shows the state during welding. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, for the sake of convenience, the dimensional ratios of the accompanying drawings are sometimes exaggerated and different from the actual ratios. In the following description, the side of the catheter that is operated is referred to as the "base end side", and the side that is inserted into the living body is referred to as the "front end side".

[0023] like Figures 1 to 3 As shown, the catheter 10 of the embodiment of the present invention has: an axis 20 as a long-sized tube body; a tube seat 40 fixed to the base end of the axis 20; and a soft anti-bending protector 60 for suppressing the bending of the axis 20. In addition to being a catheter supporting a guide wire, the catheter 10 can also be a guide catheter, an angiography catheter, a microcatheter, or a balloon catheter and an image diagnosis catheter with a dilation lumen. In addition, the catheter 10 can be a coaxial overall exchange (OTW) type in which a guide wire lumen is formed from the front end of the axis to the tube seat, or a rapid exchange (RX) type in which a guide wire lumen is formed only at the front end of the axis. For example, the guide wire lumen of the RX-type balloon catheter is formed from the front end of the axis to an opening in the middle of the axial direction of the axis. The dilation lumen for the fluid that circulates to dilate the balloon of the RX-type balloon catheter is formed from the balloon to the tube seat at the base end of the catheter.

[0024] The shaft 20 is formed with a lumen 21 that communicates from the front end to the base end. The shaft 20 has a shaft outer surface 22, a shaft inner surface 23, and a shaft base end surface 24.

[0025] The shaft outer surface 22 is a radially outer surface of the shaft 20 as a tube body, and extends from the front end to the base end of the shaft 20. The shaft outer surface 22 has a shaft base end side outer surface 25 formed from the base end toward the front end to a predetermined position. The shaft base end side outer surface 25 is surrounded and contained by the tube seat 40. The shaft base end side outer surface 25 has an outer diameter that is substantially uniform along the axis X of the shaft 20. The shaft base end side outer surface 25 has a shaft welding surface 26 welded to the tube seat 40, and a shaft separation surface 27 arranged on the front end side of the shaft welding surface 26 and separated from the tube seat 40. The shaft separation surface 27 is not welded to the tube seat 40, and is separated from the tube seat 40 with a gap. A plurality of shaft bubbles 32 are formed near the shaft welding surface 26 of the shaft 20. Each shaft bubble 32 has an inner surface that surrounds a closed space.

[0026] The shaft inner surface 23 is a radially inner surface of the shaft 20 serving as a tubular body, and extends from the front end to the base end of the shaft 20 .

[0027] The shaft proximal end surface 24 is a surface of the proximal end of the shaft 20 facing the proximal end side, and is formed by cutting perpendicularly to the axis X of the shaft 20 .

[0028] The shaft 20 in the present embodiment includes an inner layer 28 forming the shaft inner surface 23 , an outer layer 29 forming the shaft outer surface 22 , and a reinforcing body 30 embedded in the shaft 20 .

[0029] The constituent material of the outer layer 29 may include, for example, polyamide resin, polyester resin, polyolefin resin, polyurethane resin, polyamide elastomer, polyester elastomer, polyurethane elastomer, or a mixture of one or more of these or a mixture of materials with different hardnesses. The outer layer 29 may be formed by arranging materials with different hardnesses in a manner that becomes softer from the base end toward the front end.

[0030] The constituent material of the inner layer 28 may be the same material as the constituent material of the outer layer 29 described above, or may be a material different from the constituent material of the outer layer 29. In order to improve the sliding property of the inner peripheral surface of the shaft 20, the constituent material of the inner layer 28 may be a fluorine-based resin material such as polytetrafluoroethylene resin.

[0031] The reinforcing body 30 is used to reinforce the shaft 20, and is formed by weaving a plurality of reinforcing wires 31 into a cylindrical shape. In addition, the reinforcing body 30 can also be formed by winding one or more reinforcing wires 31 into a spiral shape. The material of the outer layer 29 or the inner layer 28 is fused into the gaps between the plurality of reinforcing wires 31 in the reinforcing body 30. The reinforcing wires 31 are made of metal such as stainless steel and NiTi.

[0032] The socket 40 includes a cylindrical housing portion 41 disposed on the front end side and housing the base end portion of the shaft 20, a socket body 42 disposed on the base end side of the housing portion 41, a wing portion 52, a threaded protrusion 53, and an annular protrusion 54. The socket 4 is formed with a socket inner cavity 45 communicating from a socket front end opening 43 formed at the front end of the housing portion 41 to a socket base end opening 44 formed at the base end of the socket body 42. The socket inner cavity 45 includes a housing surface 46 as the inner peripheral surface of the housing portion 41, an adjacent surface 47 facing the shaft base end surface 24, and a socket passage 48 as the inner peripheral surface of the socket body 42.

[0033] The housing surface 46 includes a tube seat welding surface 49 directly welded to the shaft welding surface 26 of the shaft base end side outer surface 25, and a tube seat separation surface 50 which is radially away from the shaft separation surface 27 and faces it. The tube seat welding surface 49 extends from the base end of the housing surface 46 to the front end direction. The base end of the tube seat welding surface 49 is connected to the adjacent surface 47. The tube seat separation surface 50 extends from the front end of the tube seat welding surface 49 to the front end direction. The gap between the tube seat separation surface 50 and the shaft base end side outer surface 25 in the radial direction expands toward the front end direction. In addition, the tube seat separation surface 50 which forms a gap with the shaft base end side outer surface 25 may not be provided. A plurality of tube seat bubbles 55 are formed near the tube seat welding surface 49 of the housing portion 41. Each tube seat bubble 55 has an inner surface which surrounds a closed space.

[0034] The adjacent surface 47 is an annular surface facing the front end side and is formed substantially perpendicular to the axis X of the shaft 20. The radial outer side of the adjacent surface 47 is connected to the stem welding surface 49. The radial inner side of the adjacent surface 47 is connected to the front end of the stem passage 48.

[0035] The tube seat passage 48 extends from the adjacent surface 47 toward the base end. The tube seat passage 48 has an inner diameter that gradually increases toward the base end and is formed in an inclined shape. The tube seat passage 48 is coaxial with the receiving surface 46, and more preferably, coaxial with the lumen 21. The inner diameter of the front end of the tube seat passage 48 is preferably substantially consistent with the inner diameter of the shaft 20, but is not limited thereto. A portion of the inclined tube seat passage 48 may also have a Luer inclined portion 51 that can be connected to a syringe (not shown). The guide wire and treatment catheter inserted from the tube seat base end opening 44 can smoothly pass through the tube seat lumen 45 and the lumen 21 and protrude from the front end of the catheter 10. As a result, the guide wire and treatment catheter 10 can easily reach the target location such as the lesion.

[0036] The wing portion 52 is formed to protrude from two opposite positions of the outer peripheral surface of the tube seat body 42 so that the surgeon can hold the tube seat 40 for easy operation. The threaded protrusion 53 is formed on the outer peripheral surface of the base end side of the tube seat body 42. The threaded protrusion 53 can be engaged with a locking type syringe or the like. The annular protrusion 54 is a protrusion formed within 360° on the outer peripheral surface of the housing portion 41. The annular protrusion 54 can be engaged with a groove formed on the inner peripheral surface of the anti-bending protector 60.

[0037] The constituent material of the stem 40 is not particularly limited as long as it is a thermoplastic resin that can be injection molded, but is preferably a material that easily transmits heat or electromagnetic waves, and specific examples thereof include polyolefin resins, polyamide resins, polycarbonate resins, and polyester resins.

[0038] Next, the method of welding the shaft 20 and the tube seat 40 will be described. Figure 4 As shown, the inner diameter of the receiving surface 46 is larger on the front end side than on the base end side. Specifically, the inner diameter D1 of the front end opening 43 of the tube seat is larger than the inner diameter D2 of the front end and base end of the tube seat welding surface 49. In addition, the inner diameter D3 of the front end of the tube seat passage 48 is smaller than the inner diameter D2 of the base end of the tube seat welding surface 49. The inner diameter D2 of the tube seat welding surface 49 is substantially consistent with the outer diameter of the outer surface 25 on the base end side of the shaft. The inner diameter D1 of the front end opening 43 of the tube seat is, for example, 0.92 mm. The inner diameter D2 of the base end of the tube seat welding surface 49 is, for example, 0.88 mm. The inner diameter D3 of the front end of the tube seat passage 48 is, for example, 0.57 mm.

[0039] First, the base end side of the shaft 20 is inserted into the housing portion 41, and the shaft base end surface 24 is brought into contact with the adjacent surface 47. In addition, the shaft base end surface 24 may not be brought into contact with the adjacent surface 47, and a gap may exist between the shaft base end surface 24 and the adjacent surface 47. In addition, the base end of the shaft base end side outer surface 25 is brought into contact with the base end of the tube seat welding surface 49. In addition, the shaft base end side outer surface 25 may not be brought into contact with the tube seat welding surface 49, and a gap may exist between the shaft base end side outer surface 25 and the tube seat welding surface 49.

[0040] Next, a heating rod (not shown) is inserted into the lumen 21 of the shaft 20 to heat the outer surface 25 on the base end side of the shaft and the receiving portion 41 of the tube seat 40. As a result, the outer surface 25 on the base end side of the shaft and the receiving surface 46 are melted, and the tube seat welding surface 49 and the shaft welding surface 26 are welded. The tube seat welding surface 49 and the shaft welding surface 26 can also be mixed to form an integral structure. The heating method is not particularly limited, and for example, a method of irradiating electromagnetic waves with a wavelength that penetrates the tube seat 40 but does not penetrate the outer surface 22 of the shaft can be cited. Since the outer surface 22 of the shaft does not penetrate electromagnetic waves, the outer surface 25 on the base end side of the shaft is heated and melted first. In addition, the heat of the outer surface 25 on the base end side of the shaft is transferred to the receiving portion 41, causing the receiving portion 41 to melt.

[0041] Electromagnetic waves include heat, microwaves, and visible light, and also include infrared rays. Infrared rays are near infrared rays with a wavelength of about 0.7 μm to 2.5 μm, mid infrared rays with a wavelength of about 2.5 μm to 4 μm, or far infrared rays with a wavelength of about 4 μm to 1000 μm, but may include one or more of near infrared rays, mid infrared rays, or far infrared rays, and may also include visible light or microwaves.

[0042] The method of irradiating electromagnetic waves is not particularly limited, and may be semiconductor solid laser such as YAG laser using neodymium, or fiber laser.

[0043] Electromagnetic wave penetration means that, in addition to being transparent to the naked eye through visible light, the measured transmittance (hereinafter referred to as transmittance) is 80% or more, more preferably 85% or more. The transmittance can be measured by irradiating a sheet having a thickness of 0.4 mm to 0.5 mm made by melting and pressing resin pellets with electromagnetic waves of a specific wavelength and using a spectroscopic analysis device such as a Fourier transform infrared near infrared spectroscopic analysis device. Therefore, since electromagnetic waves are not limited to visible light, electromagnetic wave penetration includes the case where, although it appears colored or opaque to the naked eye, it is transparent to a specific wavelength.

[0044] In addition, electromagnetic wave non-transmission means that, in addition to being opaque or colored to the naked eye through visible light, it also means that the transmittance is less than 80%, preferably less than 10%, and more preferably less than 1%. Therefore, since electromagnetic waves are not limited to visible light, electromagnetic wave non-transmission includes the situation that although it appears transparent to the naked eye, it is opaque or absorbs with respect to a specific wavelength.

[0045] The outer layer 29 may be mixed with a pigment that does not transmit or absorbs heat or electromagnetic waves, and the ratio of the pigment is 0.01wt% or more but less than 10wt% of the entire resin, preferably 0.05wt% or more but less than 5wt%, and more preferably 0.1wt% or more but less than 1%. Alternatively, the outer layer 29 may not contain a pigment and a contrast agent, and the resin forming the outer layer 29 may have a low transmittance with respect to a specific wavelength. Alternatively, the outer layer 29 may be mixed with a metal having X-ray contrast properties instead of or together with the pigment.

[0046] The pigment is not particularly limited as long as it is white, black, blue, red, yellow or a mixture thereof, but a black pigment such as carbon black is preferred as a pigment that easily absorbs electromagnetic waves. X-ray contrast agents are compounds of gold, bismuth or tungsten, and are more preferably in powder form.

[0047] For example, Figure 5 As shown in (A), when the shaft 20 and the stem 40 are welded by irradiating infrared laser light L, the electromagnetic wave penetrating the stem 40, which is transparent to the wavelength of the irradiated infrared laser light L, is mainly absorbed by the opaque resin or pigment of the outer layer 29 of the shaft 20, generating heat. As a result, the resin of the outer layer 29 melts and transfers heat H to the housing portion 41 of the stem 40, and at least a portion of the housing surface 46 melts. Figure 5 As shown in (B), the melted receiving surface 46 is reduced in diameter and in close contact with the outer surface 25 on the shaft base end side, and is welded to the outer surface 25 on the shaft base end side. As a result, the tube seat welding surface 49 and the shaft welding surface 26 are welded and formed. At this time, although the receiving surface 46 is melted and reduced in diameter, almost no heat is transferred to the outer peripheral surface of the receiving portion 41, so it is not dissolved and almost no deformation occurs. Therefore, through the reduction in diameter of the receiving surface 46, the material constituting the receiving surface 46 flows in a manner that fills the gap between the outer surfaces 25 on the shaft base end side, as a result, the length of the receiving portion 41 along the axis X is reduced. As a result, the receiving portion 41 and the outer surface 25 on the shaft base end side are well welded without a gap. In addition, the shaft base end surface 24 and the adjacent surface 47 are also melted and welded by the heat of the outer layer 29. In addition, the shaft base end surface 24 may not be welded to the adjacent surface 47.

[0048] If the shaft base end side outer surface 25 and the receiving surface 46 are welded, Figure 3As shown, shaft bubbles 32 are formed near the shaft welding surface 26 of the shaft 20, and tube seat bubbles 55 are formed near the tube seat welding surface 49 of the housing portion 41. Bubbles are generated by evaporation of materials and mixing of air. The shaft welding surface 26 and the tube seat welding surface 49 have concave and convex surfaces and are complexly mixed and embedded in each other by forming the shaft bubbles 32 and the tube seat bubbles 55. Therefore, the tube seat 40 and the shaft 20 are fixed with a high bonding force. The tube seat welding surface 49 and the shaft welding surface 26 can also be mixed to form an integral structure. In addition, only one of the shaft bubbles 32 or the tube seat bubbles 55 can be formed. In this case, the tube seat welding surface 49 and the shaft welding surface 26 are also complexly mixed and embedded in each other. Therefore, the tube seat 40 and the shaft 20 are fixed with a high bonding force.

[0049] The stem separation surface 50 located at the front end of the stem welding surface 49 is not welded to the shaft separation surface 27, and a gap is maintained between the stem welding surface 49 and the shaft separation surface 27. When the entire stem welding surface 49 located at the base end side of the stem separation surface 50 is welded to the shaft welding surface 26, the irradiation of the infrared laser L is stopped. Thus, the fixing of the stem 40 and the shaft 20 is completed.

[0050] As described above, the catheter 10 of the present embodiment comprises: a shaft 20 which is a tubular body, the tubular body being formed with a tubular lumen 21 which is connected from the front end to the base end, the shaft 20 having a shaft base end surface 24 for opening the tubular lumen 21 and a shaft outer surface 22 which is the outer peripheral surface of the tubular body; and a tube seat 40 mounted on the base end of the shaft 20, the tube seat 40 having a cylindrical housing portion 41 for housing the shaft 20, the housing portion 41 having a tube seat welding surface 49 which is directly welded to the shaft outer surface 22, and at least one of the housing portion 41 and the tube seat 40 having a plurality of bubbles formed at a position close to the tube seat welding surface 49.

[0051] The catheter 10 configured as described above is welded by a plurality of bubbles so that the housing portion 41 and the tube seat 40 are fitted into each other. Therefore, the shaft 20 and the tube seat 40 can be firmly fixed. Therefore, when the high pressure of the contrast medium injected into the catheter 10 acts, when the shaft 20 is pulled out of the body and a pulling force acts between the tube seat 40 and the shaft 20, it is possible to prevent the shaft 20 from being pulled out of the tube seat 40.

[0052] In addition, the housing 41 has a plurality of stem bubbles 55 formed therein near the stem welding surface 49. Thus, the stem welding surface 49 of the housing 41 has a complex shape with projections and depressions and is welded to the shaft outer surface 22. Therefore, the shaft 20 and the stem 40 can be firmly fixed.

[0053] In addition, the shaft 20 has a plurality of shaft bubbles 32 formed at positions close to the shaft welding surface 26 of the shaft outer surface 22 welded to the tube seat welding surface 49. As a result, the shaft outer surface 22 has a complex shape with irregularities and is welded to the tube seat welding surface 49. Therefore, the shaft 20 and the tube seat 40 can be firmly fixed.

[0054] In addition, both the stem 40 and the shaft 20 have a plurality of bubbles, and the stem welding surface 49 and the shaft welding surface 26 of the shaft outer surface 22 welded to the stem welding surface 49 are welded to each other with projections and depressions. Thus, the shaft 20 and the stem 40 can be fixed more firmly.

[0055] In addition, the present invention is not limited to the above-mentioned embodiment, and various changes can be made by those skilled in the art within the technical concept of the present invention. For example, the shaft 20 can also be heated by high-frequency induction heating using electromagnetic induction heating. The conductor of electromagnetic induction is, for example, the reinforcement 30.

[0056] In addition, this application claims priority based on Japanese Patent Application No. 2020-95666 filed on June 1, 2020, and the disclosed contents are incorporated herein in their entirety by reference.

[0057] Description of Reference Numerals

[0058] 10 Catheter

[0059] 20 axis

[0060] 21 Lumen

[0061] 22 Shaft outer surface

[0062] 23 Shaft inner surface

[0063] 24 axis base end face

[0064] 25 Axis base end side outer surface

[0065] 26-axis welding surface

[0066] 27 axis leaving the surface

[0067] 28 inner layer

[0068] 29 Outer Layer

[0069] 30 Strengthen the body

[0070] 32-axis bubble (bubble)

[0071] 40 Tube Socket

[0072] Containment Sector 41

[0073] 42 tube socket body

[0074] 43 Tube socket front opening

[0075] 44 Tube base opening

[0076] 45 tube seat cavity

[0077] 46 Shelter surface

[0078] 47 Adjacent faces

[0079] 48 socket access

[0080] 49 pipe seat welding surface

[0081] 50 Tube seat away from the surface

[0082] 55 tube seat bubble (bubble)

[0083] 60 anti-bending protector.

Claims

1. A catheter, comprising: A shaft of a tubular body, the tubular body being formed with a lumen communicating from the front end to the base end, the shaft having a shaft base end surface for opening the lumen and a shaft outer surface as an outer peripheral surface of the tubular body; and The tube seat is mounted on the base end of the shaft, and the catheter is characterized in that: The pipe seat has a cylindrical receiving portion for receiving the shaft. The receiving portion has a pipe seat welding surface directly welded to the outer surface of the shaft, A plurality of bubbles are formed in both the stem and the shaft near the stem welding surface, whereby the stem welding surface and the shaft welding surface of the shaft outer surface welded to the stem welding surface are welded to each other with projections and depressions.

2. The catheter according to claim 1, characterized in that The housing portion has a plurality of stem bubbles formed therein, which are bubbles, at positions close to the stem welding surface.

3. The catheter according to claim 1 or 2, characterized in that The shaft has a plurality of shaft bubbles as bubbles formed at positions close to a shaft welding surface of the shaft outer surface welded to the tube seat welding surface.

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