conduit

Abstract

The present invention provides a catheter which reduces the possibility of the shaft tube from the hub portion of the proximal end when injecting a contrast medium at high pressure or pulling out the catheter shaft tube inserted into the body. By directly fusing the shaft tube (10) with the hub portion (20) at the shaft tube housing portion (22) which houses the base end of the shaft tube and the vicinity of the base end and making somewhere in the fusion surface (40) the minimum inner diameter of the shaft tube housing portion (22), it is possible to prevent the shaft tube (10) from being separated from the hub portion (20), and without using an adhesive, to ensure the safety of the operator and further improve the yield, reduce the manufacturing cost and the cost required for safety.

Description

Technical Field

[0001] This invention relates to catheters. Background Technology

[0002] A catheter typically comprises a shaft having a lumen that communicates from the tip to the base, and a hub disposed at the base of the shaft and communicating with the lumen for connection to a syringe or similar device.

[0003] As methods for fixing the base end of the shaft tube to the hub, insert molding methods, adhesive bonding methods, and laser fusion methods are known.

[0004] Existing technical documents

[0005] Patent documents

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

[0007] Patent Document 2: Japanese Statutory Publication No. 63-17486

[0008] Patent Document 3: International Publication Publication No. 2016 / 092208 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The insert molding method shown in Patent Document 1 involves placing a shaft tube within an injection mold and pressing a portion of the shaft tube with a retaining pin, thereby injection molding the hub portion with resin under high temperature and pressure. Therefore, in the case of conduits made of different molding resins than metal needles, there is a possibility of deformation of the shaft tube or displacement of the shaft tube along its long axis due to the retaining pin.

[0011] In cases where an adhesive is used, as in Patent Document 2, if the gap between the outer diameter of the shaft tube and the inner cavity of the shaft tube housing in the hub is too small, there is a possibility that the adhesive may not be wrapped around the shaft tube and may remain in the gap between the hub and the shaft tube, thus causing contrast agent leakage during injection. Conversely, if the gap is too large, there is a possibility that the adhesive may wrap around the lumen and narrow the lumen.

[0012] Especially in support catheters for intravascular support guidewires, because the difference between the inner diameter of the tube shaft and the outer diameter of the guidewire entering the tube shaft lumen is small, if the lumen is narrow, it may be difficult to insert the guidewire into the lumen.

[0013] In addition, the use of adhesives requires protective gear such as goggles and gloves, which can be a burden for the installers.

[0014] Furthermore, in Patent Document 3, where infrared laser is used to fuse the shaft tube and hub, not only is the pigment content as high as 10 wt% or more, but also more than two kinds of pigments are used, thus making it impossible to freely choose the color of the shaft tube.

[0015] Methods for solving problems

[0016] The present invention achieves the aforementioned objectives.

[0017] (1) The catheter of the present invention is characterized in that it comprises: a shaft tube having a lumen communicating from a front end to a base end and an outer surface of the shaft tube extending along the long axis of the shaft tube; and a hub portion mounted on the base end of the shaft tube, the hub portion having a hub front end opening on a front end side, a shaft tube receiving portion for holding the shaft tube and a hub base end opening, the shaft tube receiving portion forming an abutment surface at the base end adjacent to the shaft tube base end face of the shaft tube, the abutment surface having a hole communicating with the base end opening of the hub portion and close to the base end opening of the shaft tube, the catheter having a fusion surface formed by directly fusing the base end side of the outer surface of the shaft tube on the base end side with the hub portion along the long axis of the shaft tube, the inner diameter of the front end opening of the hub portion being larger than the diameter of the abutment surface, and the inner diameter of the fusion surface being the smallest among the inner diameters of the shaft tube receiving portion.

[0018] (2) Alternatively, according to the conduit described in (1) above, the minimum inner diameter of the fusion surface of the shaft tube receiving portion is smaller than the outer diameter of the shaft tube base end face.

[0019] (3) Alternatively, according to the catheter described in (1) above, there is a gap between the outer surface of the shaft tube near the base end on the base end side compared with the fusion surface and the shaft tube receiving portion.

[0020] Invention Effects

[0021] The catheter of the present invention directly fuses the outer surface of the shaft tube to the hub without inserting an adhesive between the shaft tube and the hub. By minimizing the inner diameter of the fusion surface between the front opening of the shaft tube housing and the adjacent surface on the base end side, the shaft tube is firmly bonded to the hub, preventing high pressure during contrast agent injection and preventing the shaft tube from detaching from the hub when it is pulled out of the body.

[0022] Furthermore, since the connection between the hub and the shaft tube does not require the use of adhesives, the present invention can ensure the safety of the operator, eliminating the need for a large number of protective gear and exhaust channels to protect the operator when production is increased. Moreover, since it is less likely to cause positional misalignment during insert molding, it can reduce manufacturing costs, thus simultaneously solving the paradoxical problem of reducing both manufacturing costs and safety costs. Attached Figure Description

[0023] Figure 1 This is a plan view showing a partial cross-section of the catheter of the present invention.

[0024] Figure 2 It is an enlarged longitudinal sectional view along the long axis X of the hub and the base end of the shaft tube. Detailed Implementation

[0025] The preferred embodiments of the present invention are described below in detail with reference to the accompanying drawings. It should be noted that, for ease of explanation, the dimensions in the drawings are exaggerated and differ from the actual dimensions.

[0026] like Figure 1 As shown, the catheter 100 of the present invention has a shaft tube 10 and a hub 20. In addition to catheters that support guidewires, the catheter may also be a guiding catheter, angiography catheter, microcatheter, or a balloon catheter or imaging diagnostic catheter with a dilation lumen.

[0027] In addition, the catheter can be either an integral exchange type (OTW) type, in which the shaft and hub are connected from the front end to the base end, or a rapid exchange type (RX) balloon catheter, in which the guidewire lumen at the front end of the catheter opens in the middle of the shaft and has a lumen that connects the balloon at the front end to the hub at the base end of the catheter.

[0028] The shaft tube 10 has a cavity 17 that is connected from the front end to the base end and an outer surface 13 that extends from the front end to the base end.

[0029] like Figure 2 As shown, the base end side of the shaft tube 10 has a shaft tube base end face 16 formed by perpendicularly cutting relative to the long axis X of the shaft tube and a shaft tube base end opening 18 that serves as the base end of the lumen.

[0030] The outer surface 13 of the shaft tube has an outer surface 15 near the base end of the shaft tube and a fusion surface 40 formed by fusing with the hub, and is housed in the shaft tube housing portion 22 from the front end of the fusion surface 40 to the opening 18 at the base end of the shaft tube.

[0031] like Figures 1-2 As shown, the hub 20 has an inner cavity 30 on its inner surface that extends from the base end to the front end. The inner cavity 30 has a hub front end opening 21 and a shaft tube receiving portion 22 from the front end side, and an abutment surface 23 at the base end of the shaft tube receiving portion 22 that abuts against the shaft tube base end face 16. A hole 24 is located at the center of the abutment surface 23, opposite to the shaft tube base end opening 18 of the cavity 17. The inner diameter of the hub front end opening 21 is larger than the diameter of the abutment surface 23. Therefore, the shaft tube 10 can be easily inserted into the shaft tube receiving portion 22.

[0032] The hole 24 is approximately circular about the long axis or approximately cylindrical or frustum-shaped with a length along the long axis. It is coaxial with the shaft tube receiving part 22, more preferably coaxial with the cavity 17, and even more preferably the inner diameter of the shaft tube is the same as the inner diameter of the hole 24.

[0033] Alternatively, the base end of the hole 24 may communicate with a tapered portion 27 that widens toward the base end, the base end of the tapered portion 27 having a Luer tapered portion 28 that communicates with the hub base end opening 29 and allows a portion of the tapered portion 27 to be connected to a syringe (not shown).

[0034] Thus, the guidewire and treatment catheter inserted from the hub base opening 29 pass smoothly through the hub cavity 30 and protrude from the catheter tip via the shaft tube lumen 17, easily reaching the target location such as the lesion.

[0035] The outer side of the hub 20, starting from the front end, has a hub front end 31 with a shaft tube receiving portion 22, a main body portion 32 for holding during surgery and displaying the size of the catheter, a window portion 33, and a threaded cutting protrusion that engages with a locking syringe, etc., and a hub connector portion 34 with a hub base end opening 29.

[0036] Alternatively, a protrusion 35 that engages with a hole or recess in the anti-torsion protective sleeve (not shown) may be provided at the front end 31 of the hub.

[0037] Next, the method of fusing the shaft tube 10 and the hub 20 will be described. The base end side of the shaft tube 10 is inserted into the shaft tube receiving portion 22 and the base end face 16 of the shaft tube is brought close to the adjacent surface 23. Alternatively, the base end face 16 of the shaft tube may abut against the adjacent surface 23, or the outer edge of the base end face 16 of the shaft tube may abut against the inner surface of the front end side of the adjacent surface 23 of the shaft tube receiving portion 22, forming a gap between the base end face 16 of the shaft tube and the adjacent surface 23.

[0038] If a mandrel tube (not shown) is inserted into the cavity 17 of the shaft tube and the outer surface 13 of the shaft tube and the shaft tube receiving portion 22 of the hub 20 are heated, a fusion surface 40 is formed by melting the outer surface 13 of the shaft tube and the shaft tube receiving portion 22.

[0039] There are no particular limitations on the heating method. For example, a method that irradiates electromagnetic waves of a wavelength that passes through the hub 20 but not through the outer surface 13 of the shaft tube can be cited.

[0040] Since electromagnetic waves do not pass through the outer surface 13 of the shaft tube, the outer surface 13 of the shaft tube is first heated to melt it, and then the heat is transferred to the shaft tube receiving part 22 to melt the shaft tube receiving part 22 and form a fusion surface 40.

[0041] Electromagnetic waves include not only heat, microwaves, and visible light, but also infrared radiation. Infrared radiation refers to near-infrared radiation with wavelengths of approximately 0.7 to 2.5 μm, mid-infrared radiation with wavelengths of approximately 2.5 to 4 μm, or far-infrared radiation with wavelengths of approximately 4 to 1000 μm. However, it can also include near-infrared, mid-infrared, and far-infrared radiation, either individually or in two or more forms, or it can include visible light or microwaves.

[0042] There are no particular limitations on the method of electromagnetic wave irradiation; it can also be a semiconductor solid-state laser such as a neodymium YAG laser or a fiber laser.

[0043] Electromagnetic wave transmission refers to the measurement of transmittance (hereinafter referred to as transmittance) for a specific wavelength on a sheet material with a thickness of 0.4 to 0.5 mm, which is produced by melting and pressing resin particles, using a spectrophotometer such as a Fourier transform infrared / near-infrared spectrophotometer. The measured transmittance is 80% or more, more preferably 85% or more. Therefore, since it is not limited to visible light, it includes electromagnetic waves that are transparent for a specific wavelength even if they appear colored or opaque to the naked eye.

[0044] Furthermore, "non-transmittable" means that, except for appearing opaque or colored to the naked eye under visible light, its transmittance is less than 80%, preferably less than 10%, and more preferably less than 1%. Therefore, since it is not limited to visible light, it includes electromagnetic waves that appear transparent to the naked eye but are opaque or absorb at specific wavelengths.

[0045] Figure 2 The axial tube 10 of the conduit 100 shown has an outer layer 11 and an inner layer 12, with a reinforcing wire 14 made of braided metal wire or the like formed between them. The outer layer 11 may also be mixed with a pigment that prevents heat or electromagnetic waves from passing through or absorbs them, accounting for 0.01 wt% or more and less than 10 wt%, preferably 0.05 wt% or more and less than 5 wt%, and more preferably 0.1 wt% or more and less than 1% of the total resin.

[0046] Alternatively, it can be a structure that does not contain pigments, contrast agents, etc., and the resin has low transmittance for a specific wavelength. It can also replace pigments or mix X-ray imaging metals with pigments.

[0047] The pigment is not particularly limited and can be white, black, blue, red, yellow, or a mixture thereof. Black pigments, such as carbon black, are preferred as they readily absorb electromagnetic waves. The contrast agent is a compound of, for example, gold, bismuth, or tungsten; powdered form is more preferred.

[0048] Alternatively, it could be a substance that appears transparent to the naked eye but has low transmittance for a specific wavelength.

[0049] As the outer layer resin, in addition to polyamide resin, polyester resin, polyolefin resin, and polyurethane resin, examples include polyamide elastomer, polyester elastomer, polyurethane elastomer, or a mixture of one or more thereof, or a mixture of substances with different hardness. These elastomers may also be configured such that elastomers with different hardness are arranged in a manner that becomes softer from the base end towards the tip.

[0050] As the inner layer resin, it can be the same as the outer layer resin, or it can be a different resin from the outer layer resin, or polytetrafluoroethylene resin can be used to improve the sliding properties of the inner surface.

[0051] The hub 20 is not particularly limited, but preferably made of thermoplastic resin that can be injection molded or of a material that allows heat and electromagnetic waves to pass through. Examples of such materials include polyolefin resin, polyamide resin, polycarbonate resin, and polyester resin.

[0052] For example, when the shaft tube 10 and hub 20 are fused by irradiation with infrared laser, the electromagnetic waves transmitted through the hub 20, which is transparent to the wavelength of the irradiated infrared laser, are absorbed by the opaque resin or pigment of the outer layer 11 of the shaft tube, causing it to generate heat. This melts the resin of the outer layer 11 and transfers the heat to the shaft tube receiving portion 22 of the hub 20, causing at least a portion of the inner surface of the shaft tube receiving portion 22 to melt. If the inner surface of the shaft tube receiving portion 22 melts, the inner diameter of the shaft tube receiving portion 22 becomes smaller and comes into contact with the outer surface 13 of the shaft tube, forming a fusion surface 40.

[0053] Therefore, in terms of the inner diameter of the shaft tube receiving portion 22, the inner diameter of the fusion surface 40 is the smallest, making it difficult for the shaft tube 10 to detach from the hub portion 20.

[0054] The inner diameter of the fusion surface 40 of the shaft tube housing 22 is smaller than the inner diameter of the adjacent surface 23. This means that, for example, in a cross section perpendicular to the long axis of the shaft tube, when comparing the inner diameter of the fusion surface 40 with the inner diameter of the adjacent surface 23, the inner diameter of the fusion surface 40 is smaller than the inner diameter of the adjacent surface 23.

[0055] The difference between the inner diameter of the fusion surface 40 of the shaft tube receiving portion 22 and the inner diameter of the adjacent surface 23 is 0 mm or more and 0.5 mm or less, preferably more than 0 mm and less than 0.2 mm. If the difference is less than 0 mm, the shaft tube base end face 16 can only be inserted to the front end side of the shaft tube receiving portion 22 compared to the adjacent surface 23, thus creating a gap between the shaft tube base end face 16 and the adjacent surface 23.

[0056] If the difference between the inner diameter of the fusion surface 40 of the shaft tube housing 22 and the inner diameter of the adjacent surface 23 exceeds 0.5 mm, there is a possibility that the fusion surface 40 between the shaft tube 10 and the hub 20 may not be fully formed, resulting in a decrease in tensile strength.

[0057] Alternatively, a front end gap 25 may be formed on the front end side between the front end opening 21 of the hub and the fusion surface 40. The front end gap 25 may be the difference between the inner diameter of the hub receiving portion 22, which varies along the long axis X of the shaft tube, and the outer diameter of the shaft tube, or it may be the difference between the inner diameter of the front end gap 25, which is closer to the base end side than the front end opening 21 of the hub, and the outer diameter of the shaft tube.

[0058] The difference between the inner diameter of the front end gap 25 of the shaft tube receiving part 22 and the outer diameter of the shaft tube is greater than 0 mm and less than 0.2 mm, so that the gap can be formed to allow the shaft tube 10 to be inserted into the shaft tube receiving part 22.

[0059] Alternatively, the inner diameter of the shaft tube base end opening 18 can be made larger than the inner diameter of the hole 24 to form an outward expansion portion 19. The mandrel tube is inserted into the cavity 17 to expand the diameter of the shaft tube base end face 16, so as to prevent it from being hooked on the shaft tube base end opening 18 when the guide wire (not shown) is inserted.

[0060] Therefore, the inner diameter of the shaft tube receiving portion 22 at the fusion surface 40 is smaller than the outer diameter of the outward expansion portion 19, which serves as the base end face 16 of the shaft tube, thus preventing the shaft tube 10 from detaching from the hub portion 20.

[0061] Alternatively, a base gap 26 may be formed between the outer surface 15 near the base end of the shaft tube and the shaft tube receiving portion 22, corresponding to the gap between the base end face 16 and the adjacent surface 23.

[0062] By shortening the fusion surface 40, the processing time can be reduced.

[0063] Therefore, it is possible to prevent high pressure applied when injecting X-ray contrast agent from the contrast agent injection device (not shown) connected to the Luer cone 28 in order to observe the condition of the treatment site, and to prevent the shaft tube 10 from detaching from the hub 20 when pulling the hub 20 outward after treatment with the catheter 100.

[0064] The present invention has been described above with reference to preferred embodiments, but the present invention is not limited to the foregoing embodiments, and various changes can be made without departing from the spirit of the present invention.

[0065] It should be noted that this application is based on Japanese Patent Application No. 2020-38156, filed on March 5, 2020, the disclosure of which is applied in its entirety by reference in this specification.

[0066] Explanation of reference numerals in the attached figures

[0067] 10 shaft tubes

[0068] 11 Outer layer

[0069] 12 Inner Layer

[0070] 13. Outer surface of the shaft tube

[0071] 14 Reinforced Lines

[0072] 15. Outer surface near the base of the shaft tube

[0073] 16 Shaft tube base end face

[0074] 17. Lumen

[0075] 18. Shaft tube base opening

[0076] 19 Outward Expansion Section

[0077] 20 Hub

[0078] 21. Hub front end opening

[0079] 22 Shaft tube housing section

[0080] 23 Adjacent surfaces

[0081] 24 holes

[0082] 25. Front end gap

[0083] 26. Base gap

[0084] 27. Conical section

[0085] 28. Luer cone

[0086] 29 Hub base opening

[0087] 31 Front end of hub

[0088] 32 Hub Main Body

[0089] 33 Window section

[0090] 34 Hub connector section

[0091] 35. Protrusion

[0092] 40 fusion surfaces

[0093] X-axis tube long axis.

Claims

1. A catheter characterized by, Comprising: a shaft tube having a lumen communicating from a front end to a base end, a shaft tube base end surface, a shaft tube base end opening communicating with the lumen and provided at the shaft tube base end surface, and a shaft tube outer surface extending along a shaft tube long axis; and a hub portion mounted to the base end of the shaft tube, the hub portion having a hub portion front end opening on a front end side, a shaft tube housing portion holding the shaft tube, and a hub portion base end opening, the shaft tube housing portion being formed with an abutment surface abutting the shaft tube base end surface at the base end, the abutment surface having a hole communicating with the hub portion base end opening and proximate to the shaft tube base end opening, the catheter having a fusion surface directly fused from the base end side of the shaft tube outer surface and the hub portion along the shaft tube long axis, an inner diameter of the hub portion front end opening being larger than a diameter of the abutment surface, and an inner diameter of the fusion surface being the smallest among inner diameters of the shaft tube housing portion, a base end gap being formed between the outer surface near the base end of the shaft tube and the shaft tube housing portion corresponding to a gap between the shaft tube base end surface and the abutment surface.

2. The catheter according to claim 1, wherein the smallest inner diameter of the fusion surface of the shaft tube housing portion is smaller than an outer diameter of the shaft tube base end surface.

3. The catheter according to claim 1 or 2, wherein a gap is provided between the outer surface near the base end of the shaft tube and the shaft tube housing portion on a base end side of the fusion surface.

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