Tube sealing device and tube sealing method

Abstract

Provided is a tube sealing device and a tube sealing method that can form a sealing portion that seals the opening at the end of a thermoplastic resin tube that constitutes a medical device into a desired shape while visually checking the processing state, without using a sealing member. [Solution] The tubular sealing device (10) is a tubular sealing device for sealing a catheter tube made of thermoplastic resin, and includes a heating mold (11) having a recess (112) into which a processing area (22) extending from an end face on one end of a catheter tube material (100) to be sealed is inserted, and which heats the processing area (22) to form a sealing area (21) that seals the opening on one end of the catheter tube material (100), and a rod-shaped mandrel (14) which is inserted into the recess (112) of the heating mold (11) with the catheter tube material (100) to be sealed attached to its outer peripheral surface when the processing area (22) is heated, and at least a portion of the heating mold (11) is made of a light-transmitting material.

Description

[Technical Field]

[0001] The present invention relates to a pipe sealing device and a pipe sealing method. [Background technology]

[0002] BACKGROUND ART Medical catheters and their tip processing devices are known (see, for example, Patent Documents 1 and 2).

[0003] The medical catheter described in Patent Document 1 is an ultrasonic catheter that transmits ultrasonic waves from its distal end. It includes a tubular body constituting the catheter, an ultrasonic transducer disposed at the distal end inside the tubular body, and a distal cap as a sealing member that seals the distal opening of the tubular body. Because a portion of the distal end of this ultrasonic catheter is inserted into the body, the distal end is dome-shaped to prevent damage to biological tissue. The distal cap includes an extension extending from the opening of the tubular body into the tubular body, a dome-shaped distal protrusion that protrudes distally from the opening of the tubular body, and an outer peripheral welding surface provided on the outer peripheral surface of the extension, which is welded to the inner peripheral surface of the tubular body at the outer peripheral welding surface. Typically, before surgery, the interior of the tubular body needs to be filled with an ultrasonic propagation liquid such as saline to improve the propagation efficiency of the ultrasonic waves transmitted and received by the ultrasonic transducer, and therefore the distal opening of the tubular body is sealed.

[0004] The tip processing device described in Patent Document 2 includes a fixing device that fixes a medical resin tube in a first direction (vertical direction) so that the tip of the resin tube is exposed, a mold (outer mold) that has an insertion section (cylindrical recess) into which the tip side of the resin tube is inserted and a heater, a slider that moves the mold in the first direction, and a sensor that measures the amount of movement of the slider, and the tip side of the resin tube inserted into the insertion section is heated and melted by the mold to form a sealing section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2024-52416 [Patent Document 2] Patent No. 7128727 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the ultrasound catheter described in Patent Document 1, it is necessary to prepare a sealing member for each different radial size of the catheter tube. When the catheter tube has a small diameter, it is difficult to manufacture a small sealing member, and since a welded portion of the sealing member is required, it is difficult to process the sealing member into a short length.

[0007] According to the tip processing device described in Patent Document 2, the sealing portion is formed using only a metal outer mold, making it difficult to form the inner surface of the sealing portion into a desired shape. In addition, because the outer mold is made of metal, the processed state of the sealing portion cannot be visually observed from the outside.

[0008] An object of the present invention is to provide a tube sealing device and a tube sealing method that can form a sealing portion that seals the opening at the end of a thermoplastic resin tube that constitutes a medical device into a desired shape while visually checking the processing state, without using a sealing member. [Means for solving the problem]

[0009] [1] A tube sealing device for sealing a tube made of thermoplastic resin that constitutes a medical device, an outer mold having a recess into which a processing area extending from an end surface on one end side of a tubular body to be sealed is inserted, the processing area being heated to form a sealing portion that seals the opening on the one end side; a rod-shaped inner mold that is inserted into the recess of the outer mold with the pipe to be sealed attached to its outer peripheral surface when the processing region is heated; a holding mold that holds the outer mold and has a through hole into which the pipe to be sealed is inserted at a position corresponding to the recess of the outer mold, and the through hole guides the processing area of ​​the pipe into the recess; Equipped with At least a part of the outer mold is translucent. and low thermal conductivity formed from materials 、 The retaining mold is made of a material with high thermal conductivity.A tube sealing device. [ 2 ] The material with low thermal conductivity is a material with thermal conductivity of 5 W / m·K or less, 1 ] A pipe sealing device according to the present invention. [ 3 ] The tubular body sealing device described in [1] above further comprises a heat transfer section that is provided separately from the outer mold and transfers heat generated by a heating element when electricity is applied to the outer mold via the contact surface with the outer mold. [ 4 ] the heat transfer section is provided so as to be able to come into contact with and separate from the outer mold, 3 ] A pipe sealing device according to the present invention. [ 5 ] When the heat transfer part contacts the outer mold, a gap is formed between the heat transfer part and the holding mold. 4 ] A pipe sealing device according to the present invention. [ 6 ] The gap is provided so that the state of the processing area of ​​the pipe inserted into the recess of the outer mold can be visually observed through the gap, 5 ] A pipe sealing device according to the present invention. [ 7 ] The tubular body is a catheter tube, a part of the distal end of which is inserted into a living body, 6 ] The tubular body sealing device described in any one of the above. [ 8 ] A tube sealing device for sealing a tube made of thermoplastic resin that covers the outside of a core wire that constitutes a guide wire, an outer mold having a processing area extending from an end surface of one end of a tubular body to be sealed that protrudes from the end surface of the core wire and has a recess into which the core wire is inserted, and an outer mold for heating the processing area to form a sealing portion between the end surface of the core wire and the recess to seal the opening of the one end of the tubular body; The outer mold is at least partially formed from a light-transmitting material. [ 9 A tube sealing device for sealing a tube made of thermoplastic resin that constitutes a medical device, an outer mold having a recess into which a processing area extending from an end face on one end side of a pipe body to be sealed is inserted, and which heats the processing area to form a sealing portion that seals the opening on the one end side; and, a holding mold that holds the outer mold and has a through hole into which the pipe to be sealed is inserted at a position corresponding to the recess of the outer mold, and that guides the processing area of ​​the pipe into the recess by the through hole, At least a part of the outer mold is translucent. and low thermal conductivity formed from materials 、 The retaining mold is made of a material with high thermal conductivity. A tube sealing device. [ 10 ] A tube sealing method for sealing a tube made of a thermoplastic resin that constitutes a medical device, comprising: a mounting step of mounting a pipe to be sealed onto an outer peripheral surface of the inner mold such that a processing region extending from an end surface of one end of the pipe to be sealed protrudes from an end surface of the rod-shaped inner mold; an inserting step of inserting the processing region of the pipe body to be sealed together with the inner mold into a recessed portion of an outer mold; a heating step of heating the processing region in the outer mold to form a sealing portion that seals the opening on the one end side of the pipe body between the end surface of the inner mold and the recess, the outer mold is at least partially formed from a light-transmitting material; The heating step is performed while visually checking the processed state of the sealing portion from outside the outer mold. [ 11 ] A tube sealing method for sealing a tube made of a thermoplastic resin that covers the outside of a core wire constituting a medical guide wire, comprising: a preparation step of preparing a tubular body to be sealed such that a processing region extending from an end surface of one end of the tubular body to be sealed protrudes from an end surface of the core wire; an inserting step of inserting the processing region of the tubular body to be sealed together with the core wire into a recess formed in an outer mold; a heating step of heating the processing region with the outer mold to form a sealing portion between the end surface of the core wire and the recessed portion, the sealing portion sealing the opening on the one end side of the tubular body, the outer mold is at least partially formed from a light-transmitting material; The heating step is performed while visually checking the processed state of the sealing portion from outside the outer mold. [Effects of the Invention]

[0010] According to the present invention, a sealing portion that seals the opening at the end of a thermoplastic resin tubular body that constitutes a medical device can be formed into a desired shape without using a sealing member, while the processing state can be visually inspected. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an ultrasound catheter according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional view of the main part showing the distal end side of the catheter tube. [Figure 3] FIG. 3 is a diagram schematically illustrating an example of the general configuration of a tubular body sealing device. [Figure 4] FIG. 4 is a vertical cross-sectional view of the heating mold. [Figure 5] FIG. 5 shows an example of the holding type, where (a) is a left side view and (b) is a vertical cross-sectional view. [Figure 6] FIG. 6(a) is a vertical cross-sectional view of the heat transfer section according to the first embodiment, and FIG. 6(b) is a vertical cross-sectional view of the heat transfer section showing a modified example of FIG. 6(a). [Figure 7A] 7A(a) to 7A(c) are diagrams for explaining an example of a method for sealing a catheter tube. [Figure 7B] 7B(d) to (f) are diagrams for explaining an example of a method for sealing a catheter tube. [Figure 8] FIG. 8 is a longitudinal sectional view of a catheter tube according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a longitudinal sectional view of a medical guidewire according to a third embodiment of the present invention. [Figure 10] 10(a) and 10(b) are longitudinal cross-sectional views of essential parts for explaining an example of a method for sealing a medical guide wire. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, components having substantially the same functions are designated by the same reference numerals, and redundant explanations will be omitted. In this specification, the side inserted into the living body is referred to as the distal end, and the side operated by the surgeon is referred to as the proximal end.

[0013] [First embodiment] FIG. 1 is a diagram showing the schematic configuration of an ultrasound catheter according to a first embodiment of the present invention. This ultrasound catheter 1 includes a catheter tube 2A, a distal end of which is inserted into a body, a handle 3 for operating the catheter tube 2A, a cable 4 extending from the handle 3, and a connector 5 connected to an end of the cable 4. The connector 5 is connected to an ultrasound imaging diagnostic device (not shown). The ultrasound catheter 1 is an example of a medical instrument. The catheter tube 2A is an example of a tubular body made of a thermoplastic resin that constitutes a medical instrument. Note that the medical instrument is not limited to the ultrasound catheter 1, and may be other medical catheters or guidewires for examination, treatment, etc.

[0014] The catheter tube 2A has a lumen 2a as an opening along the axial direction, and the distal end of the lumen 2a is a sealed distal end portion 2b. The catheter tube 2A has a length and outer diameter depending on the intended use, etc. The length of the catheter tube 2A can be, for example, 0.5 m or less, more than 0.5 m but less than 1.0 m, or 1.0 m or more. The outer diameter of the catheter tube 2A can be, for example, 3 mm (9 Fr) or less, or 1 mm (3 Fr) or less.

[0015] An ultrasonic transducer 6 that transmits and receives ultrasonic waves is built into the lumen 2a of the catheter tube 2A at its tip, and a drive shaft 7 that holds the ultrasonic transducer 6 is housed along the central axis. Before surgery, the lumen 2a of the catheter tube 2A is filled with an ultrasonic propagation liquid such as saline to increase the propagation efficiency of the ultrasonic waves transmitted and received by the ultrasonic transducer 6. The ultrasonic transducer 6 converts electrical signals from an ultrasonic imaging diagnostic device into ultrasonic waves and transmits them toward the target site within the living body. The ultrasonic transducer 6 also receives reflected waves from the target site within the living body, converts them into electrical signals, and transmits them to the ultrasonic imaging diagnostic device. This allows the ultrasonic imaging diagnostic device to image the target site.

[0016] The catheter tube 2A is made of a flexible and ultrasonically transmissive material, such as a thermoplastic resin such as a polyolefin resin or a polyamide resin. The ultrasonically transmissive material preferably has a specific gravity close to that of blood or an ultrasonic wave-transmitting liquid (for example, a specific gravity of 0.9 to 1.2 or 1.0 to 1.1) in order to suppress the reflection of ultrasonic waves. The catheter tube 2A may have a structure in which a reinforcing layer made of metal wire, fiber, or the like is provided in the portion excluding the distal end portion 2b. The reinforcing layer may be provided, for example, between the inner layer and the outer layer.

[0017] By operating the handle 3, the drive shaft 7 rotates the ultrasonic transducer 6 around the central axis of the catheter tube 2A. The sensor built into the distal end of the catheter tube 2A is not limited to the ultrasonic transducer 6, but may be other sensors such as a temperature sensor, an image sensor, or a magnetic sensor. An optical fiber that emits laser light from its distal end may also be built into the lumen 2a of the catheter tube 2A. Sensors and optical fibers are examples of medical devices. When a medical device other than the ultrasonic transducer 6 is used, the material of the catheter tube is not limited to those described above.

[0018] (Configuration of sealing part) 2 is a longitudinal cross-sectional view of the distal end of the catheter tube 2A. The ultrasonic transducer 6 is not shown in the figure. A sealing part 21 that seals the lumen 2a at the distal end of the catheter tube 2A is provided at the distal end part 2b of the catheter tube 2A. The lumen 2a at the distal end of the catheter tube 2A is an example of an opening at one end of a tubular body.

[0019] The surface of the sealing portion 21 has, for example, a substantially hemispherical sealing portion surface 21a to prevent damage to biological tissue. The sealing portion 21 is processed (formed) by heating a processing region 22 (see FIGS. 3, 7A, etc.) extending from the end surface on the distal side of the catheter tube material 100, which will be described later. The axial thickness T of the sealing portion 21 is thicker than the thickness of the wall defining the lumen 2a. This makes it possible to prevent damage to the distal end portion 2b when the catheter tube 2A is inserted into the body or when the ultrasonic transducer 6 is operated. The axial thickness T of the sealing portion 21 may be approximately the same as the thickness of the wall defining the lumen 2a. The shape of the sealing portion surface 21a may also be another shape, such as a truncated cone.

[0020] (Configuration of the tube sealing device) FIG. 3 is a diagram showing a schematic configuration example of a tubular sealing device. This tubular sealing device 10 includes a heating mold 11, which has a recess 112 into which a processing region 22 at the distal end of a catheter tube material 100 is inserted and serves as an outer mold for heating the processing region 22 to a predetermined temperature (e.g., a temperature equal to or higher than the softening point of the catheter tube material 100) to form a sealing region 21 that seals the distal end of the lumen 2a; a holding mold 12 that holds the heating mold 11 and guides the insertion of the catheter tube material 100 before molding and the catheter tube 2A after molding; a heating device 13 that heats the heating mold 11; and a mandrel 14, which is a rod-shaped inner mold on whose outer circumferential surface the catheter tube material 100 is attached and which is used to process the distal end of the catheter tube material 100. The recess 112 is, for example, cylindrical, but may have other shapes. The catheter tube material 100 is an example of a tubular body or an object to be sealed.

[0021] The heating mold 11 is made of a material (low thermal conductivity material) with low thermal conductivity (for example, 5 W / m·K or less). Examples of low thermal conductivity materials include ceramics such as zirconia (thermal conductivity of 3 to 4 W / m·K) and glass (thermal conductivity of approximately 1 W / m·K). The holding mold 12 is made of a material (high thermal conductivity material) with high thermal conductivity (for example, 10 W / m·K or more). Examples of high thermal conductivity materials include stainless steel (thermal conductivity of 15 to 25 W / m·K).

[0022] The material constituting the heating mold 11 is preferably zirconia (transparent zirconia or opaque zirconia) from the viewpoints of resin durability, processability, demoldability, and low thermal conductivity. Furthermore, from the viewpoint of visually observing the processed state of the sealing portion 21 from the outside (e.g., the softened state of the processed region 22, the state of the resin filling the space of the recess 112, etc.), the material of the heating mold 11 is preferably translucent (including transparent and translucent). Examples of such translucent materials include glass and transparent zirconia. Of these, transparent zirconia is the best. If the heating mold 11 and the holding mold 12 were entirely made of a metal such as stainless steel, the entire mold would be heated due to the thermal conduction of the metal, potentially resulting in an appearance that the catheter tube is melted at the base end of the mold. However, this can be prevented by forming the heating mold 11 from a low thermal conductivity material and the holding mold 12 from a high thermal conductivity material. It is also conceivable to form the entire heating mold 11 and holding mold 12 from ceramics such as zirconia, but this would be very expensive, so it is preferable to use stainless steel, which is inexpensive and has good workability, for the holding mold 12. At least a portion of the heating mold 11 (for example, the entire periphery or a portion of the periphery corresponding to the gap g shown in FIG. 3) may be formed from a light-transmitting material.

[0023] The heating device 13 includes a heat generating section 131 that generates heat when powered on (for example, maximum heat generating output 100 W), a heat transfer section 132 that transfers the heat generated by the heat generating section 131 to the heating mold 11, and a control unit 133 that controls the heat generating section 131.

[0024] For example, a ceramic heater can be used as the heat generating portion 131. The ceramic heater is a ceramic material having a resistance heating element such as a tungsten wire, a molybdenum wire, or a nichrome wire embedded therein, and heats the heat transfer portion 132 from the inside.

[0025] The heat transfer part 132 is provided separately from the heating mold 11 so as to be movable toward and away from the heating mold 11, and transfers heat generated in the heat generating part 131 to the heating mold 11 via the contact surface with the heating mold 11. When the heat transfer part 132 contacts the heating mold 11, a gap g is formed between the heat transfer part 132 and the holding mold 12. This prevents heat from being directly transferred from the heat transfer part 132 to the holding mold 12, which would result in the catheter tube 2A appearing melted. The heat transfer part 132 can be made of a material with high thermal conductivity, such as copper. The heat transfer part 132 is equipped with a temperature sensor 134 that detects the temperature of the heat transfer part 132. The temperature sensor 134 is connected to the control unit 133 via lead wires. The detailed shape of the heat transfer part 132 will be described later.

[0026] The control unit 133 includes a temperature setting unit 135, and is configured so that the temperature of the heat transfer unit 132 can be set within a range of 50 to 450° C. The control unit 133 controls the power applied to the ceramic heater so that the temperature detected by the temperature sensor 134 is maintained at the temperature set by the temperature setting unit 135.

[0027] (Mandrel configuration) The mandrel 14 has a cross-sectional shape corresponding to the lumen 2a of the catheter tube 2A, for example, a circular cross-section, and can be made of a metal rod such as stainless steel. The distal end surface 14a of the mandrel 14 has a shape corresponding to the shape of the inner surface 21b of the sealing portion 21 of the catheter tube 2A, for example, a flat surface, with a rounded boundary between the flat surface and the outer circumferential surface. Furthermore, to eliminate the need to distinguish between the distal end surface 14a and the rear end surface 14b, the rear end surface 14b of the mandrel 14 may also be formed in the same shape as the distal end surface 14a.

[0028] The outer diameter of the mandrel 14 is preferably slightly smaller than the inner diameter of the catheter tube material 100 (for example, the difference between the outer and inner diameters is 0.02 to 0.05 mm). This makes it easy to attach the catheter tube material 100 to the outer peripheral surface of the mandrel 14, and prevents the catheter tube material 100 from falling off the mandrel 14 when they are operated as a unit. Furthermore, when the mandrel 14 with the catheter tube material 100 attached thereto is inserted into the recess 112, air existing between the distal end surface 14a of the mandrel 14 and the recess 112 can escape to the outside through the gap between the outer peripheral surface of the mandrel 14 and the inner peripheral surface of the catheter tube material 100. Note that if the difference between the outer and inner diameters is greater than 0.05 mm, molten resin will flow into the gap, deteriorating the appearance of the sealing portion 21; therefore, this difference is preferably 0.05 mm or less.

[0029] The total length of the mandrel 14 may be set to be longer than the total length of the catheter tube material 100, for example, so that the rear end surface 14b of the mandrel 14 is exposed a predetermined distance (for example, about 50 to 100 mm) from the catheter tube material 100 in the installation step described below. This makes it easier to remove the mandrel 14 from the catheter tube 2A after the sealing portion 21 is formed. If the catheter tube is relatively thick, a linear member such as a string or wire may be attached to the rear end surface 14b of the mandrel 14, and the mandrel 14 may be removed from the catheter tube 2A using this linear member. The outer peripheral surface of the mandrel 14 may be embossed to facilitate air escape and easier removal of the catheter tube when the mandrel 14 is pushed in while the resin is softened.

[0030] (Heating type configuration) 4 is a longitudinal cross-sectional view of the heating mold 11. The heating mold 11 has a cylindrical heating mold body 111, and a recess 112 into which the catheter tube material 100 is inserted is formed along the central axis of the heating mold body 111. A male thread portion 113 is formed on the outer circumferential surface of the heating mold body 111. The male thread portion 113 is for threading into a female thread portion 123 formed in the holding mold 12 shown in FIG. 5, which will be described later. The heating mold 11 is held by the holding mold 12 by this threading.

[0031] The recess 112 has, for example, a spherical curved surface 112a formed by a portion of a sphere having a radius R1 smaller than the radius of the inner diameter of the recess 112, a tapered conical side surface 112b, and a cylindrical surface 112c. The spherical curved surface 112a and the conical side surface 112b form a bottom surface 1120. The boundary between the spherical curved surface 112a and the conical side surface 112b and the boundary between the conical side surface 112b and the cylindrical surface 112c may each be rounded. Furthermore, the recess 112 may be formed by a hemispherical spherical curved surface and a cylindrical surface without using a conical side surface, or may be formed by another curved surface and a cylindrical surface.

[0032] The inner diameter D2 of the cylindrical surface 112c is preferably slightly larger than the outer diameter of the catheter tube material 100 (for example, the difference between the inner and outer diameters (0.02 to 0.05 mm)). As an example of specific sizes of the recess 112, the radius R1 of the spherically curved surface 112a may be 1.0 mm, the axial length L1 of the spherically curved surface 112a may be 0.3 mm, the depth L2 of the spherically curved surface 112a may be 0.5 mm, the axial length L3 of the conical side surface 112b may be 1.0 mm, the length L4 of the cylindrical surface 112c may be 5.7 mm, the overall length L5 of the heating mold 11 may be 8.0 mm, the maximum diameter D1 of the spherically curved surface 112a (the minimum diameter of the conical side surface 112b) may be 1.7 mm, the inner diameter D2 of the cylindrical surface 112c may be 2.2 mm, and the outer diameter D3 of the heating mold 11 may be 4.0 mm.

[0033] (Retentive configuration) FIG. 5 shows an example of the holding mold 12, with (a) being a left side view and (b) being a longitudinal cross-sectional view. The holding mold 12 has a holding mold body 121 that is approximately cylindrical and has flat sides. A through-hole 122 that penetrates in the axial direction and has a circular cross-section is formed at a position corresponding to the recess 112 of the heating mold 11 (for example, coaxial with the recess 112) as shown in FIG. 3. If the through-hole 122 has a relatively large inner diameter, it may be formed eccentrically with respect to the central axis of the recess 112. A female screw portion 123 is formed in a part of the through-hole 122, and the entrance of the through-hole 122 has rounded corners 124. The female screw portion 123 is intended to be threadedly engaged with the male screw portion 113 formed in the heating mold 11 shown in FIG. 4. This threaded engagement allows the holding mold 12 to hold the heating mold 11. The mandrel 14, to which the catheter tube material 100 is attached, is inserted into the through-hole 122 of the retention mold 12, so the inner diameter of the through-hole 122 is preferably larger than the maximum outer diameter of the catheter tube material 100. In addition, the overall length of the retention mold 12 is preferably shorter than the overall length of the mandrel 14.

[0034] (Configuration of heat transfer section) FIG. 6(a) is a longitudinal cross-sectional view of a heat transfer unit 132 according to the first embodiment, and FIG. 6(b) is a longitudinal cross-sectional view of a heat transfer unit showing a modified example of FIG. 6(a). The temperature sensor and heat generating unit 131 are not shown in FIG. The heat transfer unit 132 has a rod shape, and a concave heating mold contact portion 132a with a depth Dp is formed at one axial end. A heat generating unit accommodating portion 132b for accommodating the heat generating unit 131 is formed along the central axis. As shown in FIG. 6(a), the heating mold contact portion 132a has multiple contact surfaces for contacting the heating mold 11, namely, a first contact surface 1321 formed by a flat surface and a second contact surface 1322 formed by a cylindrical surface. The heating mold contact portion 132a has multiple contact surfaces, allowing the heat transfer unit 132 to efficiently transfer heat generated by the heat generating unit 131 to the heating mold 11.

[0035] 6(b), the contact surface of the heating mold contact portion 132a with the heating mold 11 is only the first contact surface 1321. In order to visually check the processed state of the sealing portion 21, an opening may be provided in the heat transfer portion 132, or a camera may be built into the heat transfer portion 132. Furthermore, the quality of the processed state of the sealing portion 21 may be automatically determined by the camera based on image analysis.

[0036] (Sealing method) Next, an example of a method for sealing the catheter tube 2A will be described with reference to Figures 7(a) to 7(f). Here, a case where the distal end side of the lumen 2a of the catheter tube 2A is sealed will be described.

[0037] (1) Installation process First, as shown in FIG. 7(a), the catheter tube material 100 is attached to the outer peripheral surface of a mandrel 14 having an outer diameter that fits the inner diameter of the catheter tube material 100 to be sealed. At this time, the catheter tube material 100 is protruded from the distal end surface 14a on the distal end side of the mandrel 14 by a predetermined length Lo toward the distal end. The protruding region is the processing region 22, and this length (protruding length) Lo is determined so that the volume of the protruding portion of the catheter tube material 100 is equal to the volume of the sealing portion 21. For example, when the inner diameter of the catheter tube material 100 is d and the outer diameter is D, the volume Va of the protruding portion of the catheter tube material 100 is calculated by (πD 2 / 4-πd 2 When the sealing portion 21 is made hemispherical, the volume Vb of the sealing portion 21 can be expressed as (2 / 3)π(D / 2) 3 From the above equations, Lo is determined so that Va=Vb.

[0038] (2) Insertion process 7(b), the catheter tube material 100 attached to the outer peripheral surface of the mandrel 14 is manually grasped together with the mandrel 14 and inserted into the through-hole 122 of the holding mold 12 to which the heating mold 11 is attached and the recess 112 of the heating mold 11. At this stage, the heating mold 11 is not yet heated, and therefore the distal end of the catheter tube material 100 does not deform, and the distal end of the catheter tube material 100 stops at the position where it abuts against the entrance of the bottom surface 1120 of the recess 112. The length La of the catheter tube material 100 in contact with the recess 112 may be longer than the protruding length Lo, and may be, for example, 1.5 to 3 times Lo.

[0039] (3)Heating process Next, as shown in FIG. 7(c), electricity is applied to the heat generating element 131 of the heating device 13 to heat the heat transfer element 132 to a predetermined temperature (for example, a temperature equal to or higher than the softening point of the catheter tube material 100), and then the heating die contact portion 132a of the heat transfer element 132 is brought into contact with the heating die 11. The heat transfer element 132 transfers the generated heat to the heating die 11, which then heats the processing region 22 of the catheter tube material 100. At this time, the mandrel 14 is gripped together with the catheter tube material 100 and continues to be pressed into the heating die 11 with a constant pushing force F (the value varies depending on the tube inner diameter and material, but is, for example, 0.5 to 2 N). After the processing region 22 of the catheter tube material 100 has been heated and a certain time (for example, about 10 seconds) has elapsed, the processing region 22 becomes softened. When the processing region 22 softens, the mandrel 14 and the catheter tube material 100 receive a pushing force and advance toward the distal end. The space in the recess 112 is then filled with the softened resin in the processing region 22, preventing the mandrel 14 and the catheter tube material 100 from advancing (stopping). As the mandrel 14 and the catheter tube material 100 advance, air in the space in the recess 112 escapes to the outside through the gap between the recess 112 and the outer circumferential surface of the catheter tube material 100, or between the outer circumferential surface of the mandrel 14 and the inner circumferential surface of the catheter tube material 100. The halt in the advancement of the mandrel 14 and the catheter tube material 100 is considered to indicate that the sealing portion 21 has been formed into the desired shape. Because there is a large difference between the speed of the mandrel 14 and the catheter tube material 100 when they advance (e.g., approximately 2 to 5 mm / s) and the speed at which they stop (e.g., 0.2 mm / s), it is considered possible for a person to sense the advance and stoppage. It is preferable to advance and stop the mandrel 14 etc. while visually checking from outside the heating mold 11 through the gap g that the resin is filling the space of the recess 112 and forming the sealing portion 21 into the desired shape.

[0040] Alternatively, a gripping section may be used that grips the mandrel 14 together with the catheter tube material 100, and a pushing section that pushes the gripping section toward the recess 112 with a constant pushing force F. The gripping section may be realized, for example, by a pair of clamping members that clamp the catheter tube material 100 from the sides. The pushing section may be realized, for example, by a pressing means such as a spring member or a hydraulic cylinder. Furthermore, the halt of the progress of the mandrel 14 and the catheter tube material 100 may be determined using a sensor that detects the target position, movement amount, or movement speed of the mandrel 14 and the catheter tube material 100.

[0041] (4) Cooling process 7(d), while the mandrel 14 and catheter tube material 100 are pressed against the heating mold 11, the heating mold 11 is removed from the heat transfer section 132 of the heating device 13, and the entire assembly (heating mold 11, holding mold 12, and sealing target) is cooled for a predetermined time (for example, about 10 to 15 seconds). If pressure is no longer applied to the sealing portion 21 while it is cooling, the sealing portion 21 may deform (abnormally shrink) or air bubbles may form in the sealing portion 21. Therefore, it is important to continue to press the mandrel 14 and the catheter tube material 100 even during cooling. Furthermore, it is preferable to apply pressure by pressing the mandrel 14, etc., while visually checking the cooling of the sealing portion 21 from outside the heating mold 11.

[0042] Next, as shown in FIG. 7( e ), the catheter tube 2 A is pulled out together with the mandrel 14 from the through-hole 122 of the holding mold 12 to which the heating mold 11 is attached and the recess 112 of the heating mold 11 .

[0043] Next, as shown in Fig. 7(f), the mandrel 14 is removed from the catheter tube 2A. In this manner, the catheter tube 2A with the distal end side sealed is formed.

[0044] (Effects of the first embodiment) The tubular body sealing device 10 according to the first embodiment provides the following effects. (a) The shape of the sealing portion 21 can be determined by the tip shapes of the outer heating mold 11 and the inner mandrel 14, so the sealing portion surface 21a and inner surface 21b of the sealing portion 21 can be formed into the desired shape. (b) Because the heating mold 11 is made of a low-thermal-conductivity material such as zirconia, it is easier to release the mold than when it is made of metal. Furthermore, because the heating mold 11 is made of a low-thermal-conductivity material and the holding mold 12 is made of a high-thermal-conductivity material, it is possible to prevent portions of the catheter tube 2A other than the processing region 22 from melting, which would cause a poor appearance, compared to when the heating mold 11 and the holding mold 12 are entirely made of a metal such as stainless steel. (c) Because only the portion of the catheter tube material 100 to be molded by the heating mold 11 is heated, thermal deformation of the entrance portion of the heating mold 11 can be suppressed. That is, as shown in Fig. 7(c), the heating mold contact portion 132a of the heat transfer part 132 does not contact the heating mold 11 over the entire length, but contacts the heating mold 11 only in an area whose depth Dp covers the sealing portion 21, so that thermal deformation of the entrance portion of the recess 112 of the heating mold 11 can be suppressed. (d) The axial thickness of the sealing portion 21 is thicker than the thickness of the wall defining the lumen 2a, so it is less likely to deform when inserted into the body, improving operability. In addition, it is less likely to be damaged even if the ultrasonic transducer 6 hits it. (e) By forming the heating mold 11 from a light-transmitting material, it is possible to check the softening state of the processing area 22 and the state in which the resin is filling the space of the recess 112, making processing easier and reducing the risk of failure. When the heat transfer part 132 shown in Fig. 6(b) is used, only the first contact surface 1321 of the heating mold contact part 132a comes into contact with the heating mold 11, so it takes a little longer for the processing area 22 to soften, but it becomes possible to visually check the processing state of the entire sealing part 21.

[0045] [Second embodiment] 8 is a longitudinal sectional view of a catheter tube according to a second embodiment of the present invention. The catheter tube 2B according to the second embodiment differs from the first embodiment mainly in the shape of its outer circumferential surface.

[0046] The catheter tube 2B according to the second embodiment has an axial lumen 2a, the distal end of which is a distal portion 2b sealed by a sealing portion 21, and a small diameter portion 2c, a tapered portion 2d, and a large diameter portion 2e connected from the sealing portion 21 toward the proximal end. The small diameter portion 2c has an outer diameter equal to the maximum diameter of the sealing portion 21. The tapered portion 2d has an outer diameter that increases continuously from the distal end toward the proximal end. The large diameter portion 2e has an outer diameter equal to the maximum outer diameter of the tapered portion 2d. The large diameter portion 2e may have a structure including a reinforcing layer made of metal wire, fiber, or the like. The reinforcing layer may be provided, for example, between the inner layer and the outer layer.

[0047] According to the catheter tube 2B of the second embodiment, the lumen 2a on the tip side can be sealed in the same manner as in the first embodiment, and the same effects as in the first embodiment can be achieved.

[0048] [Third embodiment] 9 is a longitudinal cross-sectional view of a medical guidewire according to a third embodiment of the present invention. This medical guidewire 8 includes a core wire 81 and a coating layer 82 that coats the outside of the core wire 81. The guidewire 8 is an example of a medical device. The coating layer 82 is an example of a resin tubular body.

[0049] Core wire 81 includes small-diameter portion 811 having a circular cross section and a constant outer diameter, large-diameter portion 813 located closer to the rear end than small-diameter portion 811, also having a circular cross section and a larger outer diameter than small-diameter portion 811, and tapered portion 812 located between small-diameter portion 811 and large-diameter portion 813, whose outer diameter continuously increases from the distal end to the proximal end. This configuration reduces rigidity at the distal end and allows for flexibility. Note that the cross-sectional shape of core wire 81 does not have to be circular, and the outer diameter may be constant along its entire length.

[0050] The material from which the core wire 81 is made is not particularly limited as long as it is flexible and has a certain degree of rigidity, and for example, metals such as Ni-Ti alloys and stainless steel, and resins can be used.

[0051] The material of the coating layer 82 may be, for example, a thermoplastic resin such as a polyolefin resin, a polyurethane resin, a polyamide resin, or a fluorine resin.

[0052] (Manufacturing method) Next, an example of a method for manufacturing the guidewire 8 will be described.

[0053] (1) Preparation process Core wire 81 having small diameter portion 811, tapered portion 812 and large diameter portion 813 is manufactured by machining (cutting, polishing, grinding, forging, drawing and drawing using a split die, etc.) or chemical processing (etching, etc.).

[0054] Next, a tube 820 manufactured by extrusion molding or the like is placed over the outer peripheral surface of the core wire 81, excluding the distal end surface 81a and the proximal end surface 81b. At this time, the distal end side of the tube 820 is cut and fixed at a position protruding a predetermined length from the distal end surface 81a of the core wire 81, as shown in Figure 10(a). The protruding region is the processing region 84a. The protruding length Loa is determined so that the volume of the protruding portion of the tube 820 is equal to the volume of the sealing portion 83a on the distal side.

[0055] 10(b), the rear end of the tube 820 is cut and fixed at a position protruding a predetermined length from the rear end surface 81b of the core wire 81. The protruding region is the processing region 84b. The protruding length Lob is determined so that the volume of the protruding portion of the tube 820 is equal to the volume of the sealing portion 83b on the base end side.

[0056] (2) Insertion process Next, as described in the first embodiment, the core wire 81, the outer periphery of which is covered with the tube 820, is inserted from the tip side into the through-hole 122 of the holding mold 12 to which the heating mold 11 is attached and the recess 112 of the heating mold 11. At this time, the core wire 81 and the tube 820 are continuously pressed toward the heating mold 11 with a constant pushing force F (for example, 0.5 to 2 N).

[0057] (3)Heating process Next, as described in the first embodiment, the heat generating unit 131 is energized, and the heat transfer unit 132 is heated to a predetermined temperature. The heat transfer unit 132 is then brought into contact with the heating die 11. The heat transfer unit 132 transfers the generated heat to the heating die 11, which then heats the processing area 84a of the tube 820. After a certain period of time has passed since the processing area 84a of the tube 820 was heated, the processing area 84a becomes softened. Once the processing area 84a softens, the core wire 81 and the tube 820 receive a pushing force and advance toward the distal end. The space in the recess 112 is then filled with the resin in the softened processing area 84a, preventing the core wire 81 and the tube 820 from advancing (stopping). As the core wire 81 and the tube 820 advance, air in the space in the recess 112 escapes to the outside through the gap between the recess 112 and the outer circumferential surface of the tube 820. It is preferable to advance and stop the core wire 81, etc. while visually checking from outside the heating mold 11 through the gap g that the resin is filling the space in the recess 112 and forming the sealing portion 83a into the desired shape.

[0058] The core wire 81 and the tube 820 may be inserted using a gripping portion and a pushing portion, as in the first embodiment, and the stopping of the progress of the core wire 81 and the tube 820 may be determined using a sensor that detects the target position, movement amount, or movement speed of the core wire 81 and the tube 820.

[0059] (4) Cooling process Next, as explained in the first embodiment, while the core wire 81 and the tube 820 are pressed against the heating mold 11, the heating mold 11 is removed from the heat transfer section 132 of the heating device 13, and the entire assembly (heating mold 11, holding mold 12, and sealing target) is cooled for a predetermined time (for example, about 10 to 15 seconds). If pressure is no longer applied to the sealing portion 83a while it is cooling, the sealing portion 83a may deform (abnormally shrink) or air bubbles may form in the sealing portion 83a, so it is important to continue pressing the core wire 81 and the tube 820 even during cooling. Furthermore, it is preferable to apply pressure by pressing the core wire 81, etc., while visually checking the cooling of the sealing portion 83a from outside the heating mold 11.

[0060] Next, the coating layer 82 and the core wire 81 are pulled out from the through-hole 122 of the holding mold 12 and the recess 112 of the heating mold 11. In this manner, the tip end 8a of the core wire 81 is sealed with the sealing portion 83a.

[0061] The proximal end side of the guide wire 8 is also subjected to the same procedure as the distal end side, thereby forming a proximal end portion 8b in which the proximal end side of the covering layer 82 is sealed with a sealing portion 83b.

[0062] (Effects of the third embodiment) The pipe sealing device 10 according to the third embodiment provides the following effects. (a) The shape of the sealing portions 83a, 83b can be determined by the shape of the heating mold 11 and the tip end surface 81a or the rear end surface 81b of the core wire 81, so the surface and inner surface of the sealing portions 83a, 83b can be formed into the desired shape. (b) Because the heating mold 11 is made of a low thermal conductivity material such as zirconia, it is easier to release the mold than when it is made of metal. Also, because the heating mold 11 is made of a low thermal conductivity material and the holding mold 12 is made of a high thermal conductivity material, it is possible to prevent portions of the coating layer 82 of the guide wire 8 other than the processing area from melting, which would cause a poor appearance, compared to when the heating mold 11 and the holding mold 12 are entirely made of a metal such as stainless steel. (c) Since only the portion of the tube 820 to be molded by the heating mold 11 is heated, thermal deformation of the inlet portion of the heating mold 11 can be suppressed. (d) By forming the heating mold 11 from a light-transmitting material, it is possible to check the softening state of the processing areas 84a and 84b and the state in which the resin is filling the space of the recess 112, making processing easier and reducing the risk of failure.

[0063] (Variation 1) In the third embodiment, the core wire 81 is covered with the tube 820 and both ends are sealed, but this is not limited to this method and various other methods are possible. For example, the core wire 81 may be entirely covered with the covering layer 82, and then the tube may be covered and both ends of the tube may be sealed.

[0064] (Variation 2) In the above-described embodiments, the holding mold 12 is structured to hold the heating mold 11 and guide the object to be sealed, such as the catheter tube material 100, but it may be structured only to hold the heating mold 11.

[0065] (Variation 3) The heating mold 11 may be formed of a light-transmitting material in the portion exposed from the holding mold 12, and other portions may be formed of a light-non-transmitting material. Also, in order to visually check the processed state of the sealing portion from the outside, a window made of a light-transmitting material may be provided in the heating mold 11 at a position corresponding to the gap g between the heat transfer portion 132 and the holding mold 12. Also, the window may be formed thin to increase transparency.

[0066] Although the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above embodiment and various modifications and implementations are possible. For example, although the above embodiment has been described with respect to a tubular body constituting a medical device, the present invention can also be applied to fields other than medical fields.

[0067] Furthermore, some of the components of the above-described embodiments may be omitted or modified. Furthermore, in the methods of the above-described embodiments, processes may be added, deleted, modified, or interchanged. For example, in the above-described embodiments, an outer mold and an inner mold are used, but the inner mold need not be used. In this case, it is preferable that the central axes of the heating mold 11 and the heat transfer portion 132 are vertical. By making these vertical, the processing area to be sealed can be inserted into the recess 112 of the heating mold 11 even without the inner mold. [Explanation of symbols]

[0068] 1...ultrasonic catheter, 2A, 2B...catheter tube, 2a...lumen, 2b...tip portion, 2c...small diameter portion, 2d...tapered portion, 2e...large diameter portion, 3...handle, 4...cable, 5...connector, 6...ultrasonic transducer, 7...drive shaft, 8...guide wire, 8a...tip portion, 8b...proximal end portion, 10...tubular body sealing device, 11...heating type, 12...holding type, 13...heating device, 14...mandrel, 14a...tip surface, 14b...rear end surface, 21...sealing portion, 21a...sealing portion surface, 21b...inner surface, 22...processing area, 81...core wire, 81a...tip surface, 81b...rear end surface, 82...coating layer, 83a, 83b...sealing portion, 84a, 84b...machining area, 100...catheter tube material, 111...heating mold body, 112...recess, 112a...spherical curved surface, 112b...conical side surface, 112c...cylindrical surface, 113...male thread portion, 121...retaining mold body, 122...through hole, 123...female thread portion, 124...corner, 131...heating portion, 132...heat transfer portion, 132a...heating mold contact portion, 132b...heating portion accommodating portion, 132c...tip surface, 133...control unit, 134...temperature sensor, 135...temperature setting portion, 811...small diameter portion, 812...tapered portion, 813...large diameter portion, 820...tube, 1120...bottom surface, 1321...first contact surface, 1322...second contact surface

Claims

1. A tube sealing device for sealing a tube made of thermoplastic resin that constitutes a medical device, an outer mold having a recess into which a processing area extending from an end surface on one end side of a tubular body to be sealed is inserted, the processing area being heated to form a sealing portion that seals the opening on the one end side; a rod-shaped inner mold that is inserted into the recess of the outer mold with the pipe to be sealed attached to its outer peripheral surface when the processing region is heated; a holding mold that holds the outer mold and has a through hole into which the pipe to be sealed is inserted at a position corresponding to the recess of the outer mold, and that guides the processing area of ​​the pipe into the recess by means of the through hole, the outer mold is at least partially formed from a material that is translucent and has low thermal conductivity; The holding mold is made of a material with high thermal conductivity. Tube sealing device.

2. The material with low thermal conductivity is a material with a thermal conductivity of 5 W / m K or less. The tube sealing device of claim 1 .

3. a heat transfer section provided separately from the outer mold, which transfers heat generated by a heating element when current is applied to the outer mold via a contact surface with the outer mold; The tube sealing device of claim 1 further comprising:

4. The heat transfer unit is provided so as to be able to come into contact with and separate from the outer mold. The tube sealing device of claim 3 .

5. When the heat transfer portion contacts the outer mold, a gap is formed between the heat transfer portion and the holding mold. The tube sealing device of claim 4.

6. The gap is provided so that the state of the processing region of the tube inserted into the recess of the outer mold can be visually observed through the gap. The tube sealing device of claim 5 .

7. The tubular body is a catheter tube, a distal end portion of which is inserted into a living body. The tube sealing device according to any one of claims 1 to 6.

8. A tube sealing device for sealing a tube made of thermoplastic resin that covers the outside of a core wire that constitutes a guide wire, an outer mold having a processing area extending from an end surface of one end of a tubular body to be sealed that protrudes from the end surface of the core wire and has a recess into which the core wire is inserted, and an outer mold for heating the processing area to form a sealing portion between the end surface of the core wire and the recess to seal the opening of the one end of the tubular body; At least a part of the outer mold is formed from a light-transmitting material. Tube sealing device.

9. A tube sealing device for sealing a tube made of thermoplastic resin that constitutes a medical device, an outer mold having a recess into which a processing area extending from an end surface on one end side of a tubular body to be sealed is inserted, the processing area being heated to form a sealing portion that seals the opening on the one end side; a holding mold that holds the outer mold and has a through hole into which the pipe to be sealed is inserted at a position corresponding to the recess of the outer mold, and that guides the processing area of ​​the pipe into the recess by means of the through hole, the outer mold is at least partially formed from a material that is translucent and has low thermal conductivity; The holding mold is made of a material with high thermal conductivity. Tube sealing device.

10. A tube sealing method for sealing a tube made of a thermoplastic resin that constitutes a medical device, comprising: a mounting step of mounting a pipe to be sealed onto an outer peripheral surface of the rod-shaped inner mold such that a processing region extending from an end surface of one end of the pipe to be sealed protrudes from an end surface of the rod-shaped inner mold; an inserting step of inserting the processing region of the pipe body to be sealed together with the inner mold into a recessed portion of an outer mold; a heating step of heating the processing region in the outer mold to form a sealing portion that seals the opening on the one end side of the pipe body between the end surface of the inner mold and the recess, the outer mold is at least partially formed from a light-transmitting material; The heating step is performed while visually observing the processed state of the sealing portion from outside the outer mold. Tube sealing method.

11. A tube sealing method for sealing a tube made of a thermoplastic resin that covers the outside of a core wire constituting a medical guide wire, comprising: a preparation step of preparing a tubular body to be sealed such that a processing region extending from an end surface of one end of the tubular body to be sealed protrudes from an end surface of the core wire; an inserting step of inserting the processing region of the tubular body to be sealed together with the core wire into a recess formed in an outer mold; a heating step of heating the processing region with the outer mold to form a sealing portion between the end surface of the core wire and the recessed portion, the sealing portion sealing the opening on the one end side of the tubular body, the outer mold is at least partially formed from a light-transmitting material; The heating step is performed while visually observing the processed state of the sealing portion from outside the outer mold. Tube sealing method.

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