Medical device

Abstract

This medical device includes a first tube which has a first lumen, and a second tube which has a second lumen and which is coupled to the first tube by a coating agent at a portion thereof in the longitudinal direction of the medical device.

Description

medical devices

[0001] The present invention relates to medical devices.

[0002] Medical devices for acquiring ultrasound images are known. For example, Patent Literature 1 (JP-A-2005-102626) describes a medical device including a transducer unit for transmitting and receiving ultrasound waves toward biological tissue, an imaging lumen for enabling the transducer unit and a drive shaft to move, and a guidewire lumen for allowing a guidewire to be inserted. Hereinafter, the ultrasound image acquisition mechanism including the drive shaft and the transducer unit will also be referred to as a "sensor." Using such a medical device to perform a percutaneous procedure can improve the safety and efficiency of the procedure.

[0003] JP 2017-153621 A

[0004] Here, the above-mentioned medical device is configured to have multiple lumens by combining multiple tubes to enable operation of a treatment device (e.g., a plasma guidewire or a penetration guidewire) under sensor observation. In this regard, in the device described in Patent Document 1, the first and second tubular bodies are joined by thermal fusion or adhesive bonding. However, when the first and second tubular bodies made of a resin material are thermally fused, there is a problem that the first and second tubular bodies are deformed by heat. Furthermore, when the first and second tubular bodies are bonded, there is a problem that disadvantages arise due to hardening of the adhesive (e.g., reduced flexibility and operability, reduced acoustic characteristics).

[0005] This problem is not limited to medical devices with built-in sensors, but is also common to medical devices that are configured to allow a sensor to be inserted and are used in combination with the sensor. Furthermore, this problem is not limited to the vascular system, but is common to medical devices inserted into various organs within the human body, such as the lymphatic system, biliary system, urinary system, respiratory tract system, digestive system, secretory glands, and reproductive organs.

[0006] The present invention has been made to solve at least some of the above-mentioned problems, and aims to avoid the disadvantages that may arise from using adhesives in medical devices having multiple tubes while suppressing deformation of the tubes.

[0007] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0008] (1) According to one aspect of the present invention, there is provided a medical device comprising: a first tube having a first lumen; and a second tube having a second lumen, the second tube being bonded to the first tube by a coating agent along a portion of the length of the medical device.

[0009] This configuration allows the first and second tubes to be bonded together using a coating agent without using heat fusion or adhesive. This prevents deformation of the first and second tubes, which occurs when the tubes are bonded together using heat fusion. It also avoids the disadvantages of bonding using adhesive, such as reduced flexibility and operability due to hardening of the bonded portion, and reduced acoustic characteristics at the bonded portion.

[0010] (2) In the medical device of the above aspect, the first lumen may be for inserting a sensor that acquires image information. With this configuration, the medical device can be configured as a device that can be used in combination with a sensor that acquires image information.

[0011] (3) In the medical device of the above aspect, the second tube may have an acoustic window in which a wall of the second tube is present over the entire circumferential direction, and the first tube and the second tube may be bonded by the coating agent over at least a portion of the acoustic window in the longitudinal direction. With this configuration, bonding is performed by the coating agent rather than an adhesive over at least a portion of the acoustic window where sensing by the sensor (acquisition of image information) is performed, thereby preventing the adhesive from interfering with sensing by the sensor.

[0012] (4) In the medical device of the above aspect, in a cross section of the medical device including the portion bonded by the coating agent, a gap may be formed between a common circumferential line of the first tube and the second tube and the outer periphery of the first and second tubes. With this configuration, the gap does not hinder sensing by the sensor, allowing the sensor to perform sensing more effectively.

[0013] (5) In the medical device of the above aspect, the coating agent may be a base agent for a hydrophilic coating. With this configuration, the hydrophilic coating can serve to bond the first and second tubes together.

[0014] (6) In the medical device of the above aspect, the medical device may include a first marker having radiopaque properties and a second marker having radiopaque properties, the second marker being located closer to the proximal end than the first marker, and the bonding portion between the first tube and the second tube formed by the coating agent may be formed over the entire area between the first marker and the second marker. With this configuration, the entire area between the first marker and the second marker can be bonded by the coating agent.

[0015] (7) In the medical device of the above aspect, the joint between the first tube and the second tube formed by the coating agent may include a first joint and a second joint provided at a position away from the first joint toward the proximal end. With this configuration, the joint between the first and second tubes can be provided at two positions away from each other.

[0016] The present invention can be realized in various aspects, for example, in the form of a medical device, a medical tube, a catheter, and a method for manufacturing these.

[0017] 6 is an explanatory diagram illustrating the configuration of a medical device. FIG. 6 is an explanatory diagram illustrating the configuration of a medical device. FIG. 6 is a transverse sectional view of a catheter. FIG. 6 is a diagram illustrating a method of using a catheter. FIG. 6 is a diagram illustrating a method of using a catheter. FIG. 6 is an enlarged view of a portion of the distal end side of a catheter. FIG. 6 is a transverse sectional view of a catheter taken along line F-F in FIG. 6. FIG. 6 is a transverse sectional view of a catheter of a second embodiment. FIG. 6 is a transverse sectional view of a catheter of a third embodiment. FIG. 6 is an enlarged view of a portion of the distal end side of a catheter of a fourth embodiment. FIG. 6 is an enlarged view of a portion of the distal end side of a catheter of a fifth embodiment. FIG. 6 is an enlarged view of a portion of the distal end side of a catheter of a sixth embodiment.

[0018] 1 and 2 are explanatory diagrams illustrating an example of the configuration of a medical device 1. The medical device 1 of this embodiment is a catheter used to treat a lesion in a biological lumen, such as a CTO (Cardiac Tissue Occurring in a blood vessel). Hereinafter, the medical device 1 will also be referred to as a "catheter 1." As shown in FIGS. 1 and 2 , the catheter 1 includes a sensor tube 10, an over-the-wire (OTW) tube 20, a rapid exchange (RX) tube 30, a distal tip 40, a first marker 41, a second marker 42, a first outer tube 50, a branched connector 60, first to third reinforcing members 61 to 63, a tubular member 64, a connector 65, a connector 25, a sensor 70, a second outer tube 80, and a heat-shrinkable tube 90. The sensor tube 10 is also referred to as a "medical device" or a "medical tube." The OTW tube 20 is also called a "medical device" or "medical tube."

[0019] In order to explain the configuration of the tube and the lumen within the tube, the sensor 70 is not shown in Fig. 1. In Fig. 2, the sensor 70 built into the sensor lumen 10L within the sensor tube 10 is indicated by a dashed line and hatched with diagonal lines.

[0020] For ease of explanation, Figures 1 and 2 include portions in which the relative size ratios of the components are different from the actual ratios. Also, some of the components are exaggerated. Also, Figures 1 and 2 illustrate mutually orthogonal X, Y, and Z axes. The X axis corresponds to the longitudinal direction of the catheter 1, the Y axis corresponds to the height direction of the catheter 1, and the Z axis corresponds to the width direction of the catheter 1. The left side (-X axis direction) of Figures 1 and 2 is referred to as the "distal side" of the catheter 1 and each component, and the right side (+X axis direction) of Figures 1 and 2 is referred to as the "proximal side" of the catheter 1 and each component. Of the two ends of the catheter 1 and each component in the longitudinal direction (X axis direction), the one end located on the distal side is referred to as the "distal end," and the other end located on the proximal side is referred to as the "proximal end." The distal end and its vicinity are referred to as the "distal portion," and the proximal end and its vicinity are referred to as the "proximal end." The distal end is inserted into the living body, and the proximal end is operated by an operator such as a physician. These points are also common to FIG. 3 and subsequent figures.

[0021] FIG. 3 is a cross-sectional view of the catheter 1. FIG. 3(A) shows a cross-section of the catheter 1 taken along line A-A in FIG. 1. FIG. 3(B) shows a cross-section of the catheter 1 taken along line B-B in FIG. 1. FIG. 3(C) shows a cross-section of the catheter 1 taken along line C-C in FIG. 1. FIG. 3(D) shows a cross-section of the catheter 1 taken along line D-D in FIG. 1. FIG. 3(E) shows a cross-section of the catheter 1 taken along line E-E in FIG. 1. The configuration of the catheter 1 will be described below with reference to FIGS. 1 to 3.

[0022] The sensor tube 10 is a cylindrical member (tubular body) having an elongated outer shape. The sensor tube 10 extends linearly along the longitudinal direction (X-axis direction) of the catheter 1, parallel to the OTW tube 20 and the RX tube 30. A sensor lumen 10L (dashed line) for accommodating the sensor 70 is formed inside the sensor tube 10. The sensor lumen 10L is a lumen for the sensor 70.

[0023] The distal end of the sensor tube 10 is located at the same position as or slightly closer to the proximal end than the distal end of the RX tube 30 in the longitudinal direction of the catheter 1. A distal opening 101 is formed at the distal end of the sensor tube 10, connecting the distal end of the sensor lumen 10L to the outside. The distal opening 101 is a fluid outlet for maintaining a wet state inside the sensor lumen 10L. The proximal end of the sensor tube 10 is located closer to the proximal end than the proximal end of the OTW lumen 20L and the proximal end of the RX tube 30 in the longitudinal direction of the catheter 1. A first reinforcing member 61, a branch connector 60, a tubular member 64, and a connector 65 are attached to the proximal end of the sensor tube 10, from the distal end toward the proximal end. Details will be described later. A fluid supply unit 66 is attached to the connector 65, and a proximal opening 102 is formed in the fluid supply unit 66, connecting the proximal end of the sensor lumen 10L to the outside. The proximal opening 102 is a fluid supply port to the sensor lumen 10L.

[0024] 1, the sensor tube 10 includes a distal tube 11 disposed on the distal side and a proximal tube 12 disposed on the proximal side of the distal tube 11. The distal tube 11 and the proximal tube 12 are both cylindrical members (tubular bodies) having elongated outer shapes. The distal tube 11 and the proximal tube 12 are connected to each other inside the first outer tube 50 in the longitudinal direction. That is, the distal tube 11 and the proximal tube 12 each constitute a part of the sensor lumen 10L.

[0025] The OTW tube 20 is a cylindrical member (tubular body) having a long outer shape. The OTW tube 20 extends linearly along the longitudinal direction of the catheter 1, parallel to the sensor tube 10 and the RX tube 30, distal to the branch connector 60. An OTW lumen 20L (dashed line) for accommodating a therapeutic device (e.g., a plasma guidewire or a penetration guidewire) is formed inside the OTW tube 20. The OTW lumen 20L is a so-called over-the-wire (OTW) type lumen that does not have a proximal opening in the portion that is placed inside the biological lumen when the catheter 1 is in use.

[0026] The distal end of the OTW tube 20 is located closer to the proximal end than the distal end of the sensor tube 10 and the distal end of the RX tube 30 in the longitudinal direction of the catheter 1. A distal opening 201 that connects the distal end of the OTW lumen 20L to the outside is formed at the distal end of the OTW tube 20. The distal opening 201 is a device ejection port for ejecting a therapeutic device toward biological tissue. By cutting the distal end of the OTW tube 20 obliquely, the distal opening 201 faces in a direction intersecting the longitudinal direction of the catheter 1. This makes it easier for the therapeutic device to reach biological tissue present around the catheter 1 when the catheter 1 is in use. The proximal end of the OTW tube 20 is located closer to the distal end of the sensor tube 10 and closer to the proximal end of the RX tube 30 in the longitudinal direction of the catheter 1. On the proximal end side of the OTW tube 20, a first reinforcing member 61, a branch connector 60, a second reinforcing member 62, a third reinforcing member 63, and a connector 25 are attached, from the distal end side to the proximal end side. Details will be described later. The connector 25 has a proximal end opening 202 that connects the proximal end of the OTW lumen 20L to the outside. The proximal end opening 202 is a device insertion port for inserting a therapeutic device into the OTW lumen 20L.

[0027] 1 , the OTW tube 20 includes a distal tube 21 disposed on the distal side and a proximal tube 22 disposed on the proximal side of the distal tube 21. The distal tube 21 and the proximal tube 22 are both cylindrical members (tubular bodies) having an elongated outer shape. The distal tube 21 and the proximal tube 22 are connected to each other inside the first outer tube 50 in the longitudinal direction. That is, the distal tube 21 and the proximal tube 22 each constitute a part of the OTW lumen 20L.

[0028] The RX tube 30 is a cylindrical member (tubular body) having an elongated outer shape. The RX tube 30 extends linearly along the longitudinal direction of the catheter 1, parallel to the sensor tube 10 and the OTW tube 20. An RX lumen 30L (dashed line) for accommodating a work hose wire is formed inside the RX tube 30.

[0029] The distal end of the RX tube 30 is located at the same position as or slightly distal to the distal end of the sensor tube 10 in the longitudinal direction of the catheter 1. A hollow distal tip 40 is joined to the distal portion of the RX tube 30. A distal opening 301 is formed at the distal end of the distal tip 40, connecting the distal end of the RX lumen 30L to the outside. The distal opening 301 is a wire insertion port for inserting the work horse wire into the RX lumen 30L. The proximal end of the RX tube 30 is located distal to the proximal end of the sensor tube 10 and the proximal end of the OTW tube 20 in the longitudinal direction of the catheter 1. A proximal end opening 302 is formed at the proximal end of the RX tube 30, connecting the proximal end of the RX lumen 30L to the outside. The proximal end opening 302 is a wire withdrawal port for withdrawing the work horse wire to the outside. By cutting the base end of the RX tube 30 obliquely, the base end opening 302 faces in a direction intersecting the longitudinal direction of the catheter 1. This makes it easier to pull out the work hose wire from the base end opening 302 when the catheter 1 is in use.

[0030] The distal tip 40 is a radiopaque, tubular member whose outer diameter expands from the distal end to the proximal end. The distal tip 40 is positioned at the distal end of the catheter 1 by being joined to the distal portion of the RX tube 30, and advances through the biological lumen ahead of other members. The lumen of the distal tip 40 communicates with the RX lumen 30L of the RX tube 30, and as described above, a distal opening 301 is formed at the distal end of the distal tip 40, which communicates the distal end of the RX lumen 30L with the outside.

[0031] The first marker 41 and the second marker 42 are annular radiopaque members. The first marker 41 is arranged so that the base end of the first marker 41 and the base end of the distal tip 40 are aligned in the longitudinal direction of the catheter 1. The first marker 41 is embedded between the outer circumferential surface of the RX tube 30 and the inner circumferential surface of the distal tip 40. The second marker 42 is arranged so that the base end of the second marker 42 and the distal tip opening 201 are aligned in the longitudinal direction of the catheter 1. The second marker 42 is bonded to the outer circumferential surface of the RX tube 30. The first marker 41 and the second marker 42 can be bonded, for example, by thermally fusing resins or by using an adhesive such as an epoxy adhesive. The second marker 42 is visible to the naked eye. In this way, by placing the first marker 41 and the second marker 42 on the RX tube 30, it is possible to prevent the first marker 41 and the second marker 42 from interfering with sensing (acquisition of image information) by the sensor 70.

[0032] As shown in FIG. 3A, in the cross section taken along line A-A, the sensor tube 10 (specifically, the distal tube 11) and the RX tube 30 are arranged, with their outer peripheral surfaces joined together. As shown in FIG. 3B, in the cross section taken along line B-B, the sensor tube 10 (specifically, the distal tube 11), the OTW tube 20 (specifically, the distal tube 21), and the RX tube 30 are arranged, with their outer peripheral surfaces joined together. As shown in FIG. 3C, in the cross section taken along line C-C, the sensor tube 10 (specifically, the distal tube 11), the OTW tube 20 (specifically, the distal tube 21), and the RX tube 30 are covered by the first outer tube 50. Specifically, the outer peripheral surfaces of the three tubes 10, 20, and 30 are covered by the melt-formed first outer tube 50, thereby fixing the three tubes 10, 20, and 30 together. As shown in Figure 3(D) , in the cross section taken along line D-D, the sensor tube 10 (specifically, the distal tube 11), the OTW tube 20 (specifically, the proximal tube 22), and the RX tube 30 are covered by the first outer tube 50, as in Figure 3(C) . As shown in Figure 3(E) , in the cross section taken along line E-E, the sensor tube 10 (specifically, the proximal tube 12) and the OTW tube 20 (specifically, the proximal tube 22) are covered by the second outer tube 80. Specifically, the two tubes 10, 20 are fixed together by having the outer circumferential surfaces of the two tubes 10, 20 covered by the melt-molded second outer tube 80.

[0033] The sensor tube 10, the OTW tube 20, and the RX tube 30 may be joined in the A-A cross section and the B-B cross section using any bonding agent such as an epoxy adhesive, or may be thermally welded. In the A-A cross section, the B-B cross section, the C-C cross section, and the D-D cross section, the height LY of the catheter 1 is greater than the width LZ of the catheter 1. On the other hand, in the E-E cross section, the height LY of the catheter 1 is smaller than the width LZ of the catheter 1. As shown in FIGS. 3A to 3E , the relationship between the outer diameters of the three tubes 10, 20, and 30 is: outer diameter of the sensor tube 10 > outer diameter of the OTW tube 20 > outer diameter of the RX tube 30. Furthermore, the relationship between the inner diameters (lumens) of the three tubes 10, 20, and 30 is: inner diameter of the sensor lumen 10L > inner diameter of the OTW lumen 20L > inner diameter of the RX lumen 30L. However, this relationship between the outer diameter and the inner diameter is merely an example and may be changed as desired.

[0034] The A-A cross section and the B-B cross section, in other words, the outer shape of the catheter 1 distal to the first outer tube 50, is a shape that follows the contours of the two tubes 10, 30 (or the three tubes 10, 20, 30) arranged adjacent to each other, with a constriction (recess) formed in the adjacent portion of each tube. The C-C cross section and the D-D cross section, in other words, the outer shape of the catheter 1 in the portion covered by the first outer tube 50, is a triangle with rounded corners (rounded-corner triangle). The E-E cross section, in other words, the outer shape of the catheter 1 in the portion covered by the second outer tube 80, is an ellipse.

[0035] 1, the three tubes 10, 20, and 30 (specifically, the sensor tube 10, the OTW tube 20, and the RX tube 30) are fixed by three tubes 90, 50, and 80.

[0036] The heat-shrinkable tube 90 is disposed between the first outer tube 50 and the second outer tube 80 in the longitudinal direction of the catheter 1. The heat-shrinkable tube 90 covers the sensor tube 10 (specifically, a portion of the proximal tube 12 toward the distal end) and the OTW tube 20 (specifically, a portion of the proximal tube 22 toward the distal end) to bundle the two tubes 10, 20. The heat-shrinkable tube 90 does not cover the RX tube 30, which is disposed along the outer circumferential surface of the heat-shrinkable tube 90 with the outer circumferential surface of the heat-shrinkable tube 90 in contact with the outer circumferential surface of the RX tube 30. The distal end of the heat-shrinkable tube 90 is located closer to the proximal end than the distal end of the first outer tube 50 and closer to the distal end than the proximal opening 302. That is, the distal end of the heat-shrinkable tube 90 is covered by the first outer tube 50. The base end of the heat-shrinkable tube 90 is located closer to the base end than the tip of the second outer tube 80 and closer to the tip end than the first reinforcing member 61. That is, the base end of the heat-shrinkable tube 90 is covered by the second outer tube 80. In other words, the intermediate portion of the heat-shrinkable tube 90 in the longitudinal direction of the catheter 1 is not covered by the first outer tube 50 or the second outer tube 80.

[0037] The first outer tube 50 is disposed distally of the heat-shrinkable tube 90 in the longitudinal direction of the catheter 1. The first outer tube 50 is disposed proximal to the distal opening 201, in a section where the three tubes 10, 20, and 30 extend side by side. In the example shown in FIG. 1 , the distal end of the first outer tube 50 is located near the center between the distal opening 201 and the proximal opening 302. The proximal end of the first outer tube 50 is located near the proximal end of the proximal opening 302. In this manner, the first outer tube 50 is preferably disposed at a position away from the distal opening 201 toward the proximal end. This prevents the first outer tube 50 from interfering with sensing (acquisition of image information) by the sensor 70 inserted in the sensor lumen 10L. The first outer tube 50 covers and fixes the distal end portion of the heat shrink tube 90, the sensor tube 10 exposed from the distal end of the heat shrink tube 90 (specifically, a portion on the proximal end side of the distal tube 11), the OTW tube 20 exposed from the distal end of the heat shrink tube 90 (specifically, a portion on the proximal end side of the distal tube 21 and a portion on the distal end side of the proximal tube 22), and the RX tube 30. As shown in Figures 3(C) and 3(D) , the first outer tube 50 has an outer shape like a rounded triangle, and has thick-walled portions that are melt-molded along the outer peripheral surfaces of the three tubes 10, 20, and 30.

[0038] The second outer tube 80 is disposed closer to the proximal end than the heat-shrink tube 90 in the longitudinal direction of the catheter 1. The second outer tube 80 is disposed closer to the proximal end than the proximal opening 302, in a section where the two tubes 10, 20 extend side by side. In the example of FIG. 1 , the distal end of the second outer tube 80 is located slightly proximally away from the proximal opening 302. The proximal end of the second outer tube 80 is located inside the first reinforcing member 61. The second outer tube 80 covers and fixes the proximal end of the heat-shrink tube 90, the sensor tube 10 exposed from the proximal end of the heat-shrink tube 90 (specifically, a proximal portion of the proximal tube 12), and the OTW tube 20 exposed from the proximal end of the heat-shrink tube 90 (specifically, a portion of the proximal tube 22). As shown in FIG. 3(E), the second outer tube 80 has an elliptical outer shape and has a thick-walled portion that is melt-molded along the outer circumferential surfaces of the two tubes 10, 20.

[0039] The branch connector 60 is a member having a bifurcated lumen and is disposed on the proximal end side of the catheter 1. The OTW tube 20 is inserted into one lumen of the branch connector 60. The sensor tube 10 is inserted into the other lumen of the branch connector 60. The first reinforcing member 61 is a cylindrical member disposed on the distal side of the branch connector 60. The first reinforcing member 61 reinforces the distal side of the branch connector 60 by covering the outer periphery of the second outer tube 80 that bundles the sensor tube 10 and the OTW tube 20.

[0040] The second reinforcing member 62 is a cylindrical member located closer to the proximal end than one branch of the branch connector 60. The second reinforcing member 62 reinforces the proximal end of the branch connector 60 by covering the outer periphery of the OTW tube 20 inserted into the branch connector 60. The third reinforcing member 63 is a cylindrical member located closer to the distal end than the connector 25. The third reinforcing member 63 reinforces the distal end of the connector 25 by covering the outer periphery of the OTW tube 20 inserted into the connector 25. The connector 25 is a member joined to the proximal end of the OTW tube 20. The connector 25 has a pair of wings for gripping by the surgeon. A proximal end opening 202 (device insertion port) that connects the proximal end of the OTW lumen 20L to the outside is formed at the proximal end of the connector 25.

[0041] The tubular member 64 is a cylindrical member located closer to the base end than the other branch of the branch connector 60. The tubular member 64 reinforces the base end of the branch connector 60 by covering the outer periphery of the sensor tube 10 inserted into the branch connector 60. The connector 65 is a member joined to the base end of the sensor tube 10. A housing for accommodating the connection terminal 75 of the sensor 70 is provided on the base end side of the connector 65. A fluid supply section 66 is provided on the outer periphery of the connector 65, and the fluid supply section 66 has a base end opening 102 formed therein, which communicates the base end of the sensor lumen 10L with the outside.

[0042] The sensor 70 ( FIG. 2 ) is an imaging sensor for acquiring image information. As shown in FIG. 2 , the sensor 70 includes a main body 71, a probe 72, and a connection terminal 75. The main body 71 is an elongated member extending along the longitudinal direction of the catheter 1. A driving cable (coaxial cable) is built into the main body 71, electrically connecting the probe 72 and the connection terminal 75. The probe 72 includes an ultrasound probe (also called an ultrasound vibrator, piezoelectric element, ultrasound transmitting / receiving element, or ultrasound element) that transmits ultrasound toward biological tissue and receives ultrasound reflected from the biological tissue. The probe 72 is also called an imaging core or transducer. The connection terminal 75 electrically connects the sensor 70 to an external console terminal. The connection terminal 75 is provided at the base end of the main body 71 and is housed within the housing of the connector 65.

[0043] The sensor 70 is electrically connected to an external console terminal via a connection terminal 75, receives power from the console terminal, and outputs a detection signal from the probe 72 to the console terminal. This allows the console terminal to display image information based on the detection signal from the probe 72. As shown in FIG. 2 , the sensor 70 is fixed to a connector 65. As indicated by the white arrow in FIG. 2 , the surgeon grasps the connector 65 and slides it back and forth (in the direction of the white arrow) to move the position of the probe 72 of the sensor 70 within a range MR from the tip of the sensor lumen 10L to the tip of the first outer tube 50—in other words, within a predetermined range MR including the distal end opening 201. Hereinafter, this range MR will also be referred to as the “movable range MR.” Furthermore, a portion of the catheter 1 that is particularly suitable for sensing (acquisition of image information) by the sensor 70 will also be referred to as the “acoustic window AW.” As shown in FIG. 2 , the acoustic window AW is the section of the catheter 1 between the first marker 41 and the second marker 42.

[0044] The distal tube 11 of the sensor tube 10, the distal tube 21 of the OTW tube 20, and the RX tube 30 can be made of flexible materials such as thermoplastic resins such as polyethylene resin, polypropylene resin, and polyurethane, polyvinyl chloride, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, polyamide elastomer, polyolefin elastomer, polyurethane elastomer, silicone rubber, and latex rubber. The distal tube 11 of the sensor tube 10, the distal tube 21 of the OTW tube 20, and the RX tube 30 may be made of the same material or different materials.

[0045] The proximal tube 12 of the sensor tube 10 and the proximal tube 22 of the OTW tube 20 can be made of a highly rigid resin such as nylon resin, polyester resin, or PEEK resin. The melting points of the proximal tube 12 of the sensor tube 10 and the proximal tube 22 of the OTW tube 20 are higher than the melting points of the above-mentioned tubes 11, 21, and 30. The proximal tube 12 of the sensor tube 10 and the proximal tube 22 of the OTW tube 20 may be made of the same material or different materials.

[0046] In the catheter 1 of this embodiment, a section is provided in which a proximal portion of the flexible RX tube 30 overlaps with the highly rigid proximal tube 12 and proximal tube 22 ( FIG. 1 ), thereby achieving a gradual change in stiffness of the catheter 1. The gradual change in stiffness of the catheter 1 can also be said to reduce the stiffness gap of the catheter 1. This makes it possible to suppress kinking of the catheter 1. Note that one or more of the distal tube 11 and proximal tube 12 of the sensor tube 10, the distal tube 21 and proximal tube 22 of the OTW tube 20, and the RX tube 30 may have a multi-layer structure in which tubes made of different materials are overlapped.

[0047] The distal tip 40, the first marker 41, and the second marker 42 can be formed from a radiopaque resin or metal material. For example, when a radiopaque resin material is used, it can be formed by mixing a radiopaque material such as bismuth trioxide, tungsten, or barium sulfate with a polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, or fluororesin. For example, when a radiopaque metal material is used, it can be formed from gold, platinum, tungsten, or an alloy containing these elements (e.g., platinum-nickel alloy). The distal tip 40, the first marker 41, and the second marker 42 can be formed from the same material or different materials.

[0048] The branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the tubular member 64, the connector 65, and the connector 25 can be made of a known resin material. The branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the tubular member 64, the connector 65, and the connector 25 may be made of the same material or different materials.

[0049] The heat-shrinkable tube 90 is made of a thermoplastic nylon-based elastomer resin (e.g., polyamide elastomer). The heat-shrinkable tube 90 has the property of shrinking without melting when heated within a predetermined temperature range. Furthermore, the heat-shrinkable tube 90 has improved adhesiveness (the ability to easily stick to other substances) when heated compared to when not heated. The heat-shrinkable tube 90 may also be made of polyolefin, FEP (Fluorinated Ethylene Propylene), or silicone.

[0050] The first outer tube 50 and the second outer tube 80 are made of a nylon-based elastomer resin having thermoplastic properties. Unlike the heat-shrinkable tube 90, the first outer tube 50 and the second outer tube 80 have the property of melting when heated. In this embodiment, the first outer tube 50 uses a resin having a lower Shore hardness than the second outer tube 80. However, the first outer tube 50 and the second outer tube 80 may be made of the same material or different materials.

[0051] 4 and 5 are diagrams illustrating a method of using the catheter 1. Steps a1 to a6 shown below illustrate an example of attempting to recanalize a CTO (lesion) that has occurred in a blood vessel using an antegrade approach. However, the catheter 1 may also be used in a retrograde approach, or for procedures other than CTO recanalization.

[0052] (a1) The surgeon inserts the workhorse wire 200 into a blood vessel and delivers the distal end of the workhorse wire 200 to the vicinity of the CTO. (a2) The surgeon inserts the proximal end of the workhorse wire 200 from the distal opening 301 of the catheter 1, passes it through the RX lumen 30L, and pulls it out from the proximal opening 302 of the catheter 1 ( FIG. 4 ). (a3) ​​The surgeon pushes the catheter 1 along the workhorse wire 200 into the blood vessel and delivers the distal end of the catheter 1 to the vicinity of the CTO. Note that in step a3, the catheter 1 may be delivered to the vicinity of the CTO by passing it through a guiding catheter that has been inserted into the blood vessel in advance along the workhorse wire 200. (a4) The surgeon grasps the connector 65 and slides it back and forth (in the direction of the white arrow in Figure 5 ) to adjust the position of the probe 72 of the sensor 70 within the movable range MR, while checking the image displayed on the console terminal to align the position and orientation of the CTO and the distal opening 201. The term "position" refers to the position in the extension direction of the blood vessel, and the term "orientation" refers to the orientation in the circumferential direction of the inner wall of the blood vessel. (a5) The surgeon inserts the distal end of the treatment device 300 through the proximal opening 202 of the catheter 1, passes it through the OTW lumen 20L, and protrudes it from the distal opening 201 of the catheter 1 ( Figure 5 ). (a6) The surgeon treats the CTO using the treatment device 300 while adjusting the position of the probe 72 of the sensor 70 within the movable range MR as needed and checking the image displayed on the console terminal. As described above, any device, such as a plasma guidewire or a penetration guidewire, can be used as the treatment device 300.

[0053] The sensor tube 10, the OTW tube 20, and the RX tube 30 are also collectively referred to as the "shaft." The sensor tube 10 (the distal tube 11 and the proximal tube 12) corresponds to the "first tube," and the sensor lumen 10L corresponds to the "first lumen." The RX tube 30 corresponds to the "second tube," and the RX lumen 30L corresponds to the "second lumen." In this embodiment, "same" and "equal" do not necessarily mean exact agreement, but also mean allowing for differences due to manufacturing errors, etc. Furthermore, "constant" is synonymous with "approximately constant," meaning approximately constant while allowing for variations due to manufacturing errors, etc.

[0054] Fig. 6 is an enlarged view of a portion of the distal end of the catheter 1. Fig. 7 is a cross-sectional view of the catheter 1 taken along line F-F in Fig. 6. Fig. 7 (F-F cross-section) is a cross-section of the catheter 1 including the acoustic window AW. A portion of the cross-sectional view is enlarged and shown within the dashed line balloon in Fig. 7. The coupling between the sensor tube 10 and the OTW tube 20 at the distal end of the catheter 1 will be further described using Figs. 6 and 7.

[0055] As shown in Fig. 6, the section between the first marker 41 and the second marker 42 of the RX tube 30 (second tube) in the longitudinal direction of the catheter 1 is an acoustic window AW that is particularly suitable for sensing (acquisition of image information) by the sensor 70. As shown in Figs. 6 and 7, the flesh wall of the RX tube 30 is present over the entire circumferential direction of the acoustic window AW. In other words, in the section where the acoustic window AW exists, the RX tube 30 does not have any holes, notches, etc. that communicate between the inside and outside of the RX lumen 30L.

[0056] The catheter 1 of this embodiment is provided with a joint 95 over the entire area between the first marker 41 and the second marker 42 (in other words, over the entire longitudinal length of the acoustic window AW). The joint 95 is a portion where the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) are joined together by a coating agent. Hereinafter, the distal tube 11 of the sensor tube 10 and the RX tube 30 will also be simply referred to as "tubes 10, 30" or "first and second tubes 10, 30."

[0057] In this embodiment, the coating agent includes a base agent and a top agent. The base agent is an agent for improving the adhesion of the top agent to the resin tube (specifically, the distal tube 11 and the RX tube 30). Examples of the base agent that can be used include acrylic resin, acrylamide, and carboxylic acid. The top agent is an agent for imparting hydrophilicity. Examples of the top agent that can be used include well-known hydrophilic resins such as hyaluronic acid. Hereinafter, the layer formed by applying the coating agent will also be referred to as the "coating layer."

[0058] The coating layer of this embodiment includes an undercoat layer 96 formed by applying a base agent and a topcoat layer 97 formed by applying a topcoat agent. The undercoat layer 96 thinly covers the outer peripheral surface 11o of the distal tube 11 and the outer peripheral surface 30o of the RX tube 30 while contacting the outer peripheral surfaces 11o, 30o ( FIG. 7 ). As shown in the dashed-line bubble in FIG. 7 , the undercoat layer 96 penetrates between the outer peripheral surface 11o of the distal tube 11 and the outer peripheral surface 30o of the RX tube 30 in the portion where the distal tube 11 and the RX tube 30 are adjacent to each other.

[0059] The top coat layer 97 thinly covers the outer peripheral surface 96o of the undercoat layer 96 while contacting the outer peripheral surface 96o ( FIG. 7 ). As shown in the dashed line bubble in FIG. 7 , the top coat layer 97 does not penetrate between the outer peripheral surface 11o of the distal tube 11 and the outer peripheral surface 30o of the RX tube 30. That is, in the example of FIG. 7 , it can be said that the base agent of the hydrophilic coating bonds the distal tube 11 of the sensor tube 10 and the RX tube 30.

[0060] 7 shows common circumferential tangents EC1 and EC2 of the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) with dashed lines. The common circumferential tangent EC1 is also referred to as the "first common circumferential tangent EC1," and the common circumferential tangent EC2 is also referred to as the "second common circumferential tangent EC2." As shown in the figure, a gap SP1 is formed between the outer peripheries of the distal tube 11 and the RX tube 30 and the first common circumferential tangent EC1. Similarly, a gap SP2 is formed between the outer peripheries of the distal tube 11 and the RX tube 30 and the second common circumferential tangent EC2. The presence of the gaps SP1 and SP2 means that, in a cross section of the catheter 1 including the acoustic window AW, the contour of the catheter 1 has a constriction (recess) at the portion where the two adjacent tubes 11 and 30 are adjacent to each other.

[0061] The following methods b1 to b8 can be used to form the joint 95, i.e., to join the tubes 10 and 30 using a coating agent. (b1) Prepare a base liquid and a topping liquid. (b2) With the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) aligned, immerse at least the entire portion where the joint 95 is to be formed in the base liquid. In step b2, the entire distal end of the catheter 1 beyond the second marker 42 may be immersed in the base liquid, or the entire catheter 1 from the distal end to the proximal end may be immersed in the base liquid. At this time, the distal tip 40, first marker 41, and second marker 42 may already be formed on the distal end of the RX tube 30, or the tubes 10, 20, and 30 may be fixed by the first outer tube 50 or the like. (b3) Due to surface tension, the base agent liquid penetrates into the gap between the adjacent tubes 10 and 30 (Figure 7: between the outer peripheral surface 11o and the outer peripheral surface 30o). (b4) Using a cleaning tissue or the like, excess base agent liquid on the outer peripheral surfaces of the tubes 10 and 30 is absorbed to control the film thickness of the primer layer 96. (b5) The base agent liquid dries, thereby forming the primer layer 96. (b6) As in step b2, at least the entire area where the bonding portion 95 is intended to be formed is immersed in the top agent liquid. (b7) Using a cleaning tissue or the like, excess top agent liquid on the outer peripheral surface of the primer layer 96 is absorbed to control the film thickness of the top coat layer 97. (b8) The top coat agent liquid dries, thereby forming the top coat layer 97.

[0062] The undercoat layer 96 formed from the base agent has the property of "improving the adhesion of the top coating to the tubes 10, 30," and although thin, it has the property of having high adhesion to the tubes 10, 30, being resistant to mechanical loads, and not impairing the flexibility of the tubes 10, 30 even after the undercoat layer 96 (film) is formed. In this embodiment, the distal tube 11 of the sensor tube 10 and the RX tube 30 are bonded together by the undercoat layer 96 formed from the base agent, which avoids disadvantages that arise when bonding is performed using an adhesive, such as reduced flexibility and operability due to hardening of the bonding portion 95 and reduced acoustic characteristics at the bonding portion 95 (i.e., the acoustic window AW).

[0063] Specifically, when adhesive bonding is used, the hardening of the adhesive itself reduces the flexibility and acoustic properties of the catheter at the applied area. Furthermore, catheters typically have coating layers (such as a primer layer 96 or a topcoat layer 97) to impart hydrophilic or hydrophobic properties to improve torque transmission and blood vessel tracking. However, when adhesive bonding is used, an additional coating layer is formed on top of the adhesive layer, further reducing the flexibility and acoustic properties of the catheter. Furthermore, when adhesive bonding is used, it is difficult to control the thickness of the adhesive by suction using a cleaning tissue, resulting in the formation of a thick adhesive layer, making it impossible to create the aforementioned gaps SP1 and SP2. Therefore, the thick adhesive layer further reduces the flexibility and acoustic properties of the catheter, increasing the outer diameter of the catheter at that area. Such reduced acoustic properties can cause problems, such as darkening of images obtained by the sensor or the occurrence of defects.

[0064] In this regard, the catheter 1 of this embodiment does not use an adhesive with such disadvantages, but instead bonds the distal tube 11 of the sensor tube 10 and the RX tube 30 with an undercoat layer 96 formed from a base agent, thereby avoiding deterioration in flexibility and operability due to hardening of the joint 95 and deterioration in the acoustic characteristics of the joint 95 (i.e., the acoustic window AW). Furthermore, as is clear from steps b1 to b8, in this embodiment, heat is not applied when forming the joint 95 (the undercoat layer 96 and the topcoat layer 97), thereby suppressing deformation of the tubes 10, 30 caused by heat. Note that, because the section proximal to the joint 95 and distal to the first outer tube 50 does not function as the acoustic window AW, the three tubes 10, 20, 30 may be bonded by heat welding in this section.

[0065] As described above, according to the catheter 1 of the first embodiment, the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) can be bonded together using a coating agent without using heat fusion or adhesive. This suppresses deformation of the first and second tubes 10, 30 that occurs when bonding is performed using heat fusion. Furthermore, it is possible to avoid disadvantages that occur when bonding is performed using adhesive, such as reduced flexibility and operability due to hardening of the bonding portion 95, and reduced acoustic characteristics at the bonding portion 95. Furthermore, the outer diameter of the catheter 1 can be reduced at the distal end of the catheter 1 where the bonding portion 95 is provided, thereby improving passability to the lesion and reducing sliding with the combined device within the guiding catheter.

[0066] Furthermore, according to the catheter 1 of the first embodiment, the sensor lumen 10L (first lumen) is for inserting a sensor 70 that acquires image information, so the catheter 1 (medical device) can be configured as a device that can be used in conjunction with the sensor 70 that acquires image information.

[0067] Furthermore, according to the catheter 1 of the first embodiment, at least a portion of the acoustic window AW where sensing (acquisition of image information) by the sensor 70 is performed is bonded with a coating agent rather than an adhesive, which prevents the adhesive from interfering with sensing by the sensor 70. In the example of Fig. 6, the entire acoustic window AW is bonded with a coating agent rather than an adhesive, which further prevents the adhesive from interfering with sensing by the sensor 70.

[0068] Furthermore, according to the catheter 1 of the first embodiment, in a cross section of the catheter 1 including the portions bonded by the coating agent, gaps SP1, SP2 are formed between the common external tangents EC1, EC2 of the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) and the outer peripheries of the first and second tubes 10, 30. In this way, gaps SP1, SP2 that do not impede sensing by the sensor 70 allow the sensor 70 to perform sensing more effectively.

[0069] Furthermore, according to the catheter 1 of the first embodiment, the coating agent is a base agent for the hydrophilic coating, and therefore the hydrophilic coating can be used to bond the first and second tubes 10, 30. Furthermore, according to the catheter 1 of the first embodiment, the bonding portion 95 is provided over the entire space between the first marker 41 and the second marker 42 (the entire acoustic window AW), and therefore the entire space between the first marker 41 and the second marker 42 can be bonded by the coating agent.

[0070] <Second embodiment> Fig. 8 is a cross-sectional view of a catheter 1A according to a second embodiment. Fig. 8 shows a cross-section of the catheter 1A, including the acoustic window AW, taken along line F-F in Fig. 6. The catheter 1A according to the second embodiment has a coupling portion 95A instead of the coupling portion 95 in the configuration described in the first embodiment.

[0071] The joint portion 95A is a portion where the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) are joined by a coating agent consisting of only one agent. The coating agent of the second embodiment consists of only one agent that functions as both a base agent and a top agent. Examples of such coating agents include polyvinylpyrrolidone (PVP). The coating layer of the second embodiment includes a layer 97A formed by applying a coating agent. Similar to the undercoat layer 96 of the first embodiment, the layer 97A extends along the outer peripheral surfaces 11o, 30o of the tubes 10, 30, contacting and thinly covering the outer peripheral surfaces 11o, 30o, and also penetrating into the gap between the adjacent tubes 10, 30 (see FIG. 8 , between the outer peripheral surfaces 11o and 30o). That is, in the second embodiment, it can be said that the distal tube 11 of the sensor tube 10 and the RX tube 30 are bonded together by a coating agent consisting of only one agent.

[0072] As described above, the configuration of the connecting portion 95A can be modified in various ways, and the first and second tubes 10, 30 may be connected using a coating agent consisting of only one agent. Since the layer 97A functions as both a base agent and a top agent, similar to the undercoat layer 96 described in the first embodiment, it has the properties of being thin but having high adhesion to the tubes 10, 30, being resistant to mechanical loads, and not impairing the flexibility of the tubes 10, 30 even after the layer 97A (film) is formed. Therefore, the catheter 1A of the second embodiment described above can also achieve the same effects as the first embodiment described above.

[0073] <Third embodiment> Fig. 9 is a cross-sectional view of a catheter 1B according to a third embodiment. Fig. 9 shows a cross-section of the catheter 1B, including the acoustic window AW, taken along line F-F in Fig. 6. The catheter 1B according to the third embodiment has a coupling portion 95B instead of the coupling portion 95 in the configuration described in the first embodiment.

[0074] The joint portion 95B is a portion where the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) are joined by a coating agent containing three components. The coating agent of the third embodiment includes, in addition to the base agent and top agent described in the first embodiment, a second base agent disposed between the base agent and the top agent. Examples of the second base agent that can be used include acrylic resin, acrylamide, and carboxylic acid. Hereinafter, the base agent for the primer layer 96 will also be referred to as the "first base agent" for the sake of distinction.

[0075] The coating layer of the third embodiment includes an undercoat layer 96 formed by applying a first base agent, an intermediate layer 98 formed by applying a second base agent, and a topcoat layer 97B formed by applying a topcoat agent. The undercoat layer 96 is as described in the first embodiment. The intermediate layer 98 thinly covers the outer peripheral surface 96o of the undercoat layer 96 while contacting the outer peripheral surface 96o. The topcoat layer 97B thinly covers the outer peripheral surface 98o of the intermediate layer 98 while contacting the outer peripheral surface 98o. In other words, even in the example of Figure 9, it can be said that the base agent of the hydrophilic coating bonds the distal tube 11 of the sensor tube 10 and the RX tube 30.

[0076] As described above, the configuration of the coupling portion 95B can be modified in various ways, and the first and second tubes 10, 30 may be coupled together using a coating agent containing three components. Although three components are exemplified in this embodiment, a coating agent containing four or more components may also be used. The catheter 1B of the third embodiment as described above can also achieve the same effects as the first embodiment. Furthermore, the catheter 1B of the third embodiment can couple the first and second tubes 10, 30 together using any coating agent having an agent composition that corresponds to the material of the distal tube 11 and the RX tube 30.

[0077] 10 is an enlarged view of a portion of the distal end of a catheter 1C according to a fourth embodiment. The catheter 1C of the fourth embodiment includes a coupling portion 95C instead of the coupling portion 95 in the configuration described in the first embodiment. As described in the first embodiment, the section between the first marker 41 and the second marker 42 corresponds to the acoustic window AW, and therefore, hereinafter, the section between the first marker 41 and the second marker 42 will also be referred to as the "acoustic window section."

[0078] The coupling portion 95C includes a first coupling portion 95C1 and a second coupling portion 95C2. The first coupling portion 95C1 is provided at the distal end of the acoustic window section. The second coupling portion 95C2 is provided in the acoustic window section, at a position away from the proximal end from the first coupling portion 95C1. In the illustrated example, the second coupling portion 95C2 is provided at the proximal end of the acoustic window section. The first coupling portion 95C1 and the second coupling portion 95C2 are portions where the distal tube 11 (first tube) of the sensor tube 10 and the RX tube 30 (second tube) are coupled together by a coating agent. Therefore, the tubes 10 and 30 are coupled to each other by the coating agent at the first coupling portion 95C1 and the second coupling portion 95C2. On the other hand, in the portion located between the first connecting portion 95C1 and the second connecting portion 95C2 (the portion not indicated by the hatched arrow in FIG. 10), the tubes 10 and 30 are not connected. Hereinafter, this portion will also be referred to as the "unconnected portion."

[0079] As described above, the configuration of the coupling portion 95C can be modified in various ways. It is sufficient that the first and second tubes 10, 30 are coupled to each other at least in part of the acoustic window AW in the longitudinal direction of the catheter 1, and a non-coupled portion may also be included. While two coupling portions (first coupling portion 95C1 and second coupling portion 95C2) are illustrated in FIG. 10 , the coupling portion 95C may include three or more coupling portions provided at separate positions. Note that, in the non-coupled portion, the RX tube 30 may have a hole or a notch that communicates between the inside and outside of the RX lumen 30L. The catheter 1C of the fourth embodiment described above can also achieve the same effects as the first embodiment described above. Furthermore, according to the catheter 1C of the fourth embodiment, the coupling portions 95C1, 95C2 of the first and second tubes 10, 30 can be provided at two separate locations. This further improves the flexibility and acoustic characteristics of the catheter 1C in the non-coupled portion.

[0080] Fifth Embodiment Fig. 11 is an enlarged view of a portion of the distal end of a catheter 1D of a fifth embodiment. The catheter 1D of the fifth embodiment includes a coupling portion 95D instead of the coupling portion 95 in the configuration described in the first embodiment. The coupling portion 95D extends not only to the section between the first marker 41 and the second marker 42 (the acoustic window section) but also to a section proximal to the second marker 42 (more proximal to the acoustic window AW). In the illustrated example, the coupling portion 95D is provided over the entire movable range MR of the sensor 70, from the distal end of the sensor lumen 10L to the distal end of the first outer tube 50.

[0081] In this way, the configuration of the coupling portion 95D can be modified in various ways, and may be provided in any desired range in the longitudinal direction of the catheter 1D. The catheter 1D of the fifth embodiment as described above can also achieve the same effects as those of the first embodiment described above.

[0082] 12 is an enlarged view of a portion of the distal end side of a catheter 1E according to a sixth embodiment. The catheter 1E according to the sixth embodiment does not have the OTW tube 20 and the OTW lumen 20L formed by the OTW tube 20 in the configuration described in the first embodiment.

[0083] As described above, the configuration of the catheter 1E can be modified in various ways, and any part of the configuration described in the first embodiment may be omitted. For example, the sensor tube 10 may not include the distal tube 11 and the proximal tube 12, but may be configured with a single tube from the distal end to the proximal end. The sensor tube 10 may also be configured by combining three or more tubes. The catheter 1E of the sixth embodiment as described above can also achieve the same effects as the first embodiment described above.

[0084] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the present invention. For example, the following modifications are also possible.

[0085] [Modification 1] In the first to sixth embodiments, one example of the configuration of the catheters 1, 1A to 1E is shown. However, the configuration of the catheters 1, 1A to 1E can be modified in various ways.

[0086] For example, the coupling portion 95 may be provided in only a portion of the section between the first marker 41 and the second marker 42 (in other words, in only a portion of the longitudinal section of the acoustic window AW). For example, in a cross section (F-F cross section) of the catheter 1 including the acoustic window AW, the gap SP1 may not be provided between the outer peripheries of the distal tube 11 and the RX tube 30 and the first common circumferential tangent EC1. In this case, for example, an undercoat layer 96 or an overcoat layer 97 may be formed in the portion described in FIG. 7 as corresponding to the gap SP1, or the portion may be filled with a resin material or the like. Similarly, the gap SP2 between the outer peripheries of the distal tube 11 and the RX tube 30 and the second common circumferential tangent EC2 may be omitted.

[0087] For example, the outer surfaces of the first outer tube 50, the heat-shrinkable tube 90, and the second outer tube 80, or the outer surface of the catheter 1 including these, may be coated with a hydrophilic or hydrophobic resin. This coating may be a coating layer formed from the above-described coating agent (undercoat layer 96, topcoat layers 97, 97B, layer 97A, intermediate layer 98), or may be a coating layer separate from the coating layer formed from the above-described coating agent. For example, the sensor 70 is built into the sensor lumen 10L of the sensor tube 10 and is configured to be unremovable from the catheter 1. However, the sensor 70 may also be configured to be removable from the catheter 1. In other words, the catheter 1 does not need to include the sensor 70 as a component.

[0088] For example, at least one of the distal tip 40, the first marker 41, and the second marker 42 may be omitted. For example, the shapes of the distal tip 40, the first marker 41, and the second marker 42 can be changed as desired. The distal tip 40 may have a constant outer diameter from the distal end to the proximal end, and the cross-sectional shape may be asymmetrical. The first marker 41 and the second marker 42 may have a shape other than a ring shape (for example, a ring shape cut at an arbitrary angle, a wire shape, or a coil shape formed by spirally winding a wire).

[0089] For example, the positions of the distal tip 40, the first marker 41, and the second marker 42 can be changed as desired. The first marker 41 may not overlap the distal tip 40, but may be positioned adjacent to the proximal end of the distal tip 40 or at a position distant from the proximal end of the distal tip 40. The second marker 42 may be positioned at a position other than adjacent to the distal end of the distal opening 201 of the OTW tube 20 (for example, at a position distant from the distal opening 201). The first marker 41 and the second marker 42 may be positioned on a tube (sensor tube 10 or OTW tube 20) different from the RX tube 30. The first marker 41 and the second marker 42 may be positioned on the same tube as described above, or may be positioned on different tubes.

[0090] For example, at least one of the first outer tube 50 and the second outer tube 80 may be omitted. For example, in the above embodiment, the first outer tube 50 and the second outer tube 80 each consist of a single layer, but at least one of the first outer tube 50 and the second outer tube 80 may consist of two or more layers. For example, in the above embodiment, the cross-sectional shape of the portion of the catheter 1 covered by the first outer tube 50 is a rounded triangle, but it may be any shape, such as a circle or an ellipse. For example, in the above embodiment, the cross-sectional shape of the portion of the catheter 1 covered by the second outer tube 80 is an ellipse, but it may be any shape, such as a circle or a rounded triangle. For example, at least one of the first outer tube 50 and the second outer tube 80 may have an outer shape that follows the contour of the outer peripheral surface of the tube 10, 20 (or tubes 10, 20, 30).

[0091] For example, the shapes of the branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the tubular member 64, the connector 65, and the connector 25 described above are merely examples and may be changed as desired. For example, at least a portion of the branch connector 60, the first reinforcing member 61, the second reinforcing member 62, and the tubular member 64 may be configured as a single member or may be omitted. For example, the third reinforcing member 63 and the connector 25 may be configured as a single member. For example, the tubular member 64 may be provided with a mechanism (e.g., scales or stoppers provided at predetermined intervals in the longitudinal direction, or scales or stoppers provided at predetermined intervals in the circumferential direction) that assists in adjusting at least one of the front-to-rear position of the sensor 70 and the orientation of the sensor 70 in the circumferential direction.

[0092] For example, the methods for forming the joint 95 described in steps b1 to b8 are merely examples, and various modifications are possible. For example, in at least one of steps b2 and b6, instead of immersing the tubes 10 and 30 in liquid, the base agent or top agent liquid may be applied to the surface by spraying it onto the tubes 10 and 30. For example, in at least one of steps b4 and b7, controlling the film thickness by absorbing the liquid may be omitted.

[0093] [Modification 2] The configurations of the catheters 1, 1A-1E of the first to sixth embodiments and the configuration of the catheters 1, 1A-1E of Modification 1 may be combined as appropriate. For example, the coupling portions 95C, 95D described in the fourth and fifth embodiments may be formed using the coating agent (single agent, three or more agents) described in the second and third embodiments. For example, in the configurations described in the second to fifth embodiments, the OTW tube 20 may be omitted, as in the sixth embodiment.

[0094] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

Claims

1. It is a medical device, A first tube having a first lumen, A second tube having a second lumen, the second tube being bonded to the first tube by a coating agent in a portion of the longitudinal direction of the medical device, A medical device equipped with the following features.

2. A medical device according to claim 1, The first lumen is a medical device into which a sensor for acquiring image information is inserted.

3. A medical device according to claim 1, The second tube has an acoustic window where the wall of the second tube exists along its entire circumferential direction, A medical device in which the first tube and the second tube are bonded by the coating agent in at least a portion of the acoustic window in the longitudinal direction.

4. A medical device according to any one of claims 1 to 3, A medical device in which, in a cross-section of the medical device including the portion bonded by the coating agent, a gap is formed between the common outer tangent of the first tube and the second tube and the outer circumference of the first and second tubes.

5. A medical device according to any one of claims 1 to 3, The aforementioned coating agent is a hydrophilic coating base agent for a medical device.

6. A medical device according to any one of claims 1 to 3, A first marker that is radiopaque, A second marker having radiopaque properties, wherein the second marker is provided on the proximal end side of the first marker, Equipped with, A medical device in which the coating agent is used to connect the first tube and the second tube, and the joint between the first marker and the second marker is provided throughout the entire area between them.

7. A medical device according to any one of claims 1 to 3, The joint between the first tube and the second tube, formed by the coating agent, The first joint and, A second connecting portion is provided at a position away from the first connecting portion toward the base end, Medical devices, including those mentioned above.