catheter

Abstract

When a contrast medium is injected under high pressure or a catheter shaft inserted into a body is pulled out of the body, the present invention reduces the risk of the shaft slipping out of a proximal hub.　In a shaft accommodating part (22) of a hub (20), said shaft accommodating part (22) being for accommodating a shaft base end and base end vicinity, a shaft (10) is directly welded to the hub (20), and one of the welded surfaces (40) serves as the portion of the shaft accommodating part (22) having the smallest inner diameter. With this configuration, the shaft (10) can be prevented from slipping out of the hub (20) and, at the same time, worker safety can be ensured and manufacturing yield can be improved without using an adhesive, thus reducing both manufacturing costs and safety costs.

Description

[Technical field]

[0001] The present invention relates to a catheter. [Background technology]

[0002] A catheter usually has a shaft having a lumen communicating from the tip to the base end, and a hub disposed at the base end of the shaft and communicating with the lumen for connecting to a syringe or the like.

[0003] Known methods for fixing the base end of the shaft to the hub include an insert molding method, a bonding method using an adhesive, and a fusion method using a laser. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-180802 [Patent Document 2] Jpn. Jpn. Published No. 63-17486 [Patent Document 3] International Publication No. 2016 / 092208 Summary of the Invention [Problem to be solved by the invention]

[0005] In the insert molding method shown in Patent Document 1, the shaft is placed in an injection mold, part of the shaft is held down with a fixing pin, and the hub resin is injection molded at high temperature and pressure. Therefore, unlike metal needles, when molding a resin catheter, there is a risk that the fixing pin will cause deformation of the shaft or misalignment of the shaft in the longitudinal direction.

[0006] When using adhesive as in Patent Document 2, if the gap between the outer diameter of the shaft and the inner cavity of the shaft housing of the hub is too small, the adhesive will not flow in and a gap will remain between the hub and shaft, which may cause the contrast medium to leak when injected. Conversely, if the gap is too large, the adhesive may flow in the lumen and narrow it.

[0007] In particular, support catheters that support a guidewire inside a blood vessel have a small difference between the inner diameter of the shaft and the outer diameter of the guidewire that passes through the shaft lumen, so if the lumen is narrow, it may be difficult to insert the guidewire into the lumen.

[0008] Furthermore, when using adhesives, protective equipment such as goggles and gloves is required, which places a burden on the worker who wears them.

[0009] Furthermore, when fusing the shaft and hub with an infrared laser as described in Patent Document 3, the pigment content is extremely high at 10 wt % or more, and two or more types of pigments are used, so the color of the shaft cannot be freely selected. [Means for solving the problem]

[0010] The above object is achieved by the present invention described below.

[0011] (1) A catheter according to the present invention comprises a shaft having a lumen communicating from the tip to the base end and an outer surface of the shaft extending along the longitudinal axis of the shaft, and a hub attached to the base end of the shaft, the hub having a hub tip opening on the tip side, a shaft accommodating section for holding the shaft, and a hub base opening, the shaft accommodating section having an adjacent surface at its base end adjacent to the shaft base end surface of the shaft, the adjacent surface having a hole communicating with the base end opening of the hub and adjacent to the shaft base end opening, the base end side of the outer surface of the shaft on the base end side and the hub have a fused surface directly fused along the longitudinal axis of the shaft, the inner diameter of the hub tip opening is larger than the diameter of the adjacent surface, and the inner diameter of the shaft accommodating section is the smallest at the inner diameter of the fused surface. a gap is provided between the shaft outer surface proximal to the fusion surface and the shaft housing portion, and between the shaft proximal surface and the adjacent surface. , characterized in that

[0012] (2) The catheter may be as described in (1) above, in which the minimum inner diameter of the fused surface of the shaft housing portion is smaller than the outer diameter of the shaft base end surface. Effect of the Invention

[0014] In the catheter of the present invention, the outer surface of the shaft is directly fused to the hub without the use of any adhesive between the shaft and the hub, and the inner diameter of the fused surface is the smallest between the tip opening of the shaft accommodating portion and the adjacent surface on the base end, thereby firmly bonding the shaft to the hub and preventing the shaft from coming off the hub due to high pressure when contrast medium is injected or when the shaft is pulled out of the body.

[0015] Furthermore, since no adhesive is required to join the hub and shaft, it ensures the safety of workers and eliminates the need for large quantities of protective equipment and exhaust ducts to protect workers in order to increase production. Positioning problems during insert molding are also less likely to occur, so manufacturing costs can be reduced. This is an invention that can simultaneously solve the conflicting issues of reducing manufacturing costs and safety costs. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view showing a partial cross section of a catheter of the present invention. [Diagram 2] FIG. 2 is an enlarged longitudinal cross-sectional view of the hub and the proximal end of the shaft taken along the longitudinal axis X. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the dimensional ratios of the drawings may be exaggerated for the sake of explanation and may differ from the actual ratios.

[0018] A catheter 100 of the present invention has a shaft 10 and a hub 20, as shown in Fig. 1. The catheter may be a catheter that supports a guidewire, a guiding catheter, an angiography catheter, or a microcatheter, or may be a balloon catheter or an imaging diagnostic catheter having a lumen for expansion.

[0019] The catheter may be an over-the-wire (OTW) type in which the shaft and hub are connected from the tip to the base end, or a rapid exchange (RX) type balloon catheter in which the guidewire lumen at the tip of the catheter opens midway through the shaft and has a lumen that connects from the balloon at the tip to the hub at the base end of the catheter.

[0020] The shaft 10 has a lumen 17 communicating from the distal end to the proximal end and an outer surface 13 extending from the distal end to the proximal end.

[0021] As shown in FIG. 2, the proximal end side of the shaft 10 has a shaft proximal end surface 16 formed by cutting perpendicularly to the shaft longitudinal axis X, and a shaft proximal end opening 18 which is the proximal end of the lumen.

[0022] The shaft outer surface 13 has an outer surface 15 near the shaft base end from the shaft base end to the tip, and a fused surface 40 fused to the hub, and is received in the shaft receiving portion 22 from the tip end of the fused surface 40 to the shaft base end opening 18.

[0023] As shown in Figures 1 and 2, the hub 20 has a hub lumen 30 on its inner surface that communicates from the base end to the tip. The hub lumen 30 has a hub tip opening 21 and a shaft accommodating portion 22 from the tip side, and has an adjacent surface 23 adjacent to the shaft base end surface 16 at the base end of the shaft accommodating portion 22. A hole 24 is provided in the center of the adjacent surface 23 at a position facing the shaft base end opening 18 of the lumen 17. The inner diameter of the hub tip opening 21 is larger than the diameter of the adjacent surface 23. This allows the shaft 10 to be easily inserted into the shaft accommodating portion 22.

[0024] Hole 24 is approximately circular about the long axis or approximately cylindrical or frustoconical with a length in the long axis direction, and is preferably coaxial with shaft accommodating portion 22 and further with lumen 17, and it is even more preferable that the inner diameter of the shaft and the inner diameter of hole 24 are the same.

[0025] The base end of hole 24 communicates with a tapered section 27 that widens toward the base end, the base end of tapered section 27 communicates with a hub base end opening 29, and a portion of tapered section 27 may have a Luer taper section 28 that can be connected to a syringe (not shown).

[0026] This allows a guidewire or treatment catheter inserted from the hub base end opening 29 to pass smoothly through the hub lumen 30, pass through the shaft lumen 17 and protrude from the catheter tip, easily reaching the target location, such as the lesion.

[0027] The outside of the hub 20 has, from the tip side, a hub tip portion 31 which has a shaft accommodating portion 22, a body portion 32 which is grasped during surgery and on which the catheter size can be written, wings 33, and a hub connector portion 34 which has a hub base end opening 29, etc.

[0028] Hub tip 31 may also be provided with a protrusion 35 that fits into a hole or recess in an anti-kink protector (not shown).

[0029] Next, a method for fusing the shaft 10 and the hub 20 will be described. The base end side of the shaft 10 is inserted into the shaft accommodating portion 22, and the shaft base end face 16 is brought close to the adjacent surface 23. The shaft base end face 16 may abut against the adjacent surface 23, or the outer edge of the shaft base end face 16 may abut against the inner surface of the shaft accommodating portion 22 on the tip side of the adjacent surface 23, leaving a gap between the shaft base end face 16 and the adjacent surface 23.

[0030] When a mandrel (not shown) is inserted into the lumen 17 of the shaft and the shaft outer surface 13 and the shaft accommodating portion 22 of the hub 20 are heated, the shaft outer surface 13 and the shaft accommodating portion 22 melt to form a fused surface 40.

[0031] The heating method is not particularly limited, but may be, for example, a method of irradiating the hub with electromagnetic waves of a wavelength that is transmitted through the hub 20 but is opaque to the shaft outer surface 13 .

[0032] Since the shaft outer surface 13 is electromagnetically impermeable, the shaft outer surface 13 is first heated and melted, and the heat is then transferred to the shaft receiving portion 22 to melt the shaft receiving portion 22, thereby forming a fused surface 40.

[0033] Electromagnetic waves include heat, microwaves, visible light, and infrared rays. Infrared rays refer to near infrared rays with wavelengths of approximately 0.7 to 2.5 μm, mid infrared rays with wavelengths of approximately 2.5 to 4 μm, and far infrared rays with wavelengths of approximately 4 to 1000 μm. Near infrared rays, mid infrared rays, and far infrared rays may be used alone or in combination of two or more types, and may also include visible light or microwaves.

[0034] The method of irradiating the electromagnetic waves is not particularly limited, and may be a semiconductor solid-state laser such as a neodymium YAG laser, or a fiber laser.

[0035] "Transmitting electromagnetic waves" refers to something that appears transparent to the naked eye when viewed with visible light, and also means that the transmittance (hereinafter referred to as "transmittance") of a sheet of 0.4 to 0.5 mm thick made by melt pressing resin pellets is 80% or more, preferably 85% or more, measured for a specific wavelength using a spectroscopic analyzer, such as a Fourier transform infrared / near infrared spectroscopic analyzer. Therefore, since it is not limited to visible light, it also includes things that are transparent to a specific wavelength even if they appear colored or opaque to the naked eye.

[0036] In addition, being opaque to electromagnetic waves refers to materials that appear opaque or colored to the naked eye when exposed to visible light, as well as materials with a transmittance of less than 80%, preferably less than 10%, and more preferably less than 1%. Therefore, since it is not limited to visible light, it also includes materials that appear transparent to the naked eye but are opaque or absorbent to certain wavelengths.

[0037] 2 has an outer layer 11 and an inner layer 12, with a reinforcing wire 14 formed by braiding a metal wire or the like between them. The outer layer 11 may contain a pigment that is opaque to or absorbs heat or electromagnetic waves in an amount of 0.01 wt% or more and less than 10 wt%, preferably 0.05 wt% or more and 5 wt% or less, and more preferably 0.1 wt% or more and 1 wt% or less of the total resin.

[0038] Alternatively, the resin may not contain a pigment or a contrast agent and may have low transmittance for a specific wavelength, or a metal having X-ray contrast properties may be mixed in place of or together with the pigment.

[0039] The pigment is not particularly limited as long as it is a pigment that produces a white, black, blue, red, or yellow color, or a mixture thereof, but a black pigment, such as carbon black, is preferred as it easily absorbs electromagnetic waves. The contrast agent is, for example, a compound of gold, bismuth, or tungsten, and is more preferably in powder form.

[0040] Alternatively, it may be transparent to the naked eye but have low transmittance for a particular wavelength.

[0041] Examples of the outer layer resin include 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 elastomers with different hardness. These elastomers may be arranged so that the elastomers are flexible from the base end to the tip end.

[0042] The inner layer resin may be the same as the outer layer resin or may be a resin different from the outer layer resin, and may be a polytetrafluoroethylene resin in order to improve the inner surface sliding properties.

[0043] The material for the hub 20 is not particularly limited as long as it is a thermoplastic resin that can be injection molded, but it is preferable for it to be made of a material that is easily permeable to heat or electromagnetic waves, and specific examples include polyolefin resin, polyamide resin, polycarbonate resin, and polyester resin.

[0044] For example, when an infrared laser is used to fuse the shaft 10 and hub 20, 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 shaft outer layer 11, generating heat, which melts the resin of the shaft outer layer 11 and transmits the heat to the shaft accommodating portion 22 of the hub 20, melting at least a portion of the inner surface of the shaft accommodating portion 22. When the inner surface of the shaft accommodating portion 22 melts, the inner diameter of the shaft accommodating portion 22 becomes smaller and comes into contact with the shaft outer surface 13 to form a fused surface 40.

[0045] As a result, the inner diameter of the shaft accommodating portion 22 is smallest at the fused surface 40 , making it difficult for the shaft 10 to come out of the hub 20 .

[0046] The inner diameter of the fused surface 40 of the shaft accommodating portion 22 being smaller than the inner diameter of the adjacent surface 23 means that, for example, when comparing the inner diameter of the fused surface 40 with the inner diameter of the adjacent surface 23 in a cross section perpendicular to the long axis of the shaft, the inner diameter of the fused surface 40 is smaller than the inner diameter of the adjacent surface 23.

[0047] The difference between the inner diameter of the fusion surface 40 of the shaft accommodating portion 22 and the inner diameter of the adjacent surface 23 is 0 mm or more and 0.5 mm or less, and preferably is greater than 0 mm and 0.2 mm or less. If the difference is less than 0 mm, the shaft base end surface 16 can be inserted only up to the tip side beyond the adjacent surface 23 of the shaft accommodating portion 22, resulting in a gap between the shaft base end surface 16 and the adjacent surface 23.

[0048] If the difference between the inner diameter of the fusion surface 40 of the shaft accommodating portion 22 and the inner diameter of the adjacent surface 23 exceeds 0.5 mm, the fusion surface 40 between the shaft 10 and the hub 20 may not be sufficiently formed, resulting in a decrease in tensile strength.

[0049] Also, a tip gap 25 may be formed on the tip side between the hub tip opening 21 and the fusion surface 40. The tip gap 25 may be the difference between the inner diameter of the hub housing portion 22 which changes along the shaft longitudinal axis X and the outer diameter of the shaft, or may be the difference between the inner diameter of the tip gap 25 on the base end side of the hub tip opening 21 and the outer diameter of the shaft.

[0050] The difference between the inner diameter of tip gap 25 of shaft accommodating portion 22 and the outer diameter of the shaft needs to be greater than 0 mm and equal to or less than 0.2 mm so long as there is a gap that allows shaft 10 to be inserted into shaft accommodating portion 22.

[0051] The inner diameter of the shaft base end opening 18 may be made larger than the inner diameter of the hole 24 to form a flared portion 19, and a mandrel may be inserted into the lumen 17 to expand the diameter of the shaft base end surface 16 so that the guide wire (not shown) does not get caught on the shaft base end opening 18 when inserted.

[0052] As a result, the inner diameter of shaft accommodating portion 22 at fusion surface 40 becomes smaller than the outer diameter of flare portion 19 which is shaft base end surface 16 , so that shaft 10 can be prevented from coming off hub 20 .

[0053] In addition, a base end gap 26 may be formed between the shaft base end adjacent outer surface 15 and the shaft accommodating portion 22 in accordance with the gap between the shaft base end surface 16 and the adjacent surface 23 .

[0054] By shortening the fusion surface 40, the processing time can be shortened.

[0055] This prevents shaft 10 from coming out of hub 20 when high pressure is applied when an X-ray contrast agent is injected from a contrast agent injection device (not shown) connected to Luer taper portion 28 to observe the condition of the treatment site, or when hub 20 is pulled when shaft 10 inserted into the body is pulled out of the body after treatment using catheter 100.

[0056] In the above, the present invention has been described by citing preferred embodiments, but the present invention is not limited to the above embodiments, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0057] This application is based on Japanese Patent Application No. 2020-38156 filed on March 5, 2020, the disclosures of which are hereby incorporated by reference in their entirety. [Explanation of symbols]

[0058] 10 shaft, 11 outer layer, 12 inner layer, 13 Shaft outer surface, 14 Reinforcing wire, 15 outer surface near the base end of the shaft; 16 Shaft base end face, 17 lumens, 18 Shaft base end opening, 19 Flare section, 20 Hub, 21 Hub tip opening, 22 shaft receiving portion, 23 adjacent surfaces, 24 holes, 25 Tip clearance, 26 Base end gap, 27 Tapered section, 28 Lure taper part, 29 Hub base opening, 31 Hub tip, 32 Hub body part, 33 Wing, 34 Hub connector part, 35 protrusion, 40 fusion surface, X Shaft major axis.

Claims

1. A catheter comprising: a shaft having a lumen communicating from a tip end to a base end, a shaft base end surface, a shaft base end opening provided in the shaft base end surface with which the lumen communicates, and a shaft outer surface extending along a shaft longitudinal axis; a hub attached to a proximal end of the shaft; the hub has a distal end opening, a shaft accommodating portion for holding the shaft, and a hub proximal end opening on a distal end side; the shaft accommodating portion has a proximal end formed with an adjacent surface adjacent to the shaft proximal end surface of the shaft, a hole in the adjacent surface that communicates with the hub proximal end opening and is adjacent to the shaft proximal end opening; a base end side of the outer surface of the shaft and the hub have a fusion surface that is directly fused to each other along a longitudinal axis of the shaft; the inner diameter of the hub tip opening is larger than the diameter of the adjacent surface, and the inner diameter of the shaft accommodating portion is the smallest at the fusion surface; A catheter characterized in that there are gaps both between the shaft outer surface near the base end of the shaft on the base end side of the fused surface and the shaft accommodating portion, and between the shaft base end surface and the adjacent surface.

2. The catheter of claim 1 , wherein a minimum inner diameter of the fused surface of the shaft housing is smaller than an outer diameter of the shaft proximal surface.

3. A catheter as described in claim 1 or 2, wherein the inner diameter of the fused surface is smaller than the outer diameter of the shaft base end surface.

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