Medical device and method for manufacturing medical device

Abstract

This medical device comprises a first tube, a second tube, a heat shrink tube that bundles the first tube and the second tube, and a third tube that is in contact with the outside peripheral surface of the heat shrink tube.

Description

Medical device and method for manufacturing medical device

[0001] The present invention relates to medical devices and methods for manufacturing medical devices.

[0002] Catheters used in percutaneous procedures are known. For example, Patent Document 1 describes a catheter having an observation lumen in which an observation section used for observing inside a living body is disposed, a first guide wire lumen provided distal to the observation section, and a second guide wire lumen provided proximal to the observation section.

[0003] Japanese Patent Application Laid-Open No. 2006-20944

[0004] Some medical devices are constructed by bundling multiple tubes together to improve safety and operability while satisfying required performance. Due to differences in the properties of these multiple tubes, bundling multiple tubes at once can be difficult. However, the technology described in Patent Document 1 does not take such issues into consideration at all. Note that such issues are not limited to the vascular system, but are common to medical devices inserted into various organs within the human body, such as the lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs.

[0005] The present invention has been made to solve at least part of the above-mentioned problems, and aims to provide a technology that can integrate multiple tubes in a medical device having multiple tubes, even if the properties of each tube differ.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following aspects.

[0007] (1) According to one aspect of the present invention, there is provided a medical device comprising: a first tube, a second tube, a heat-shrinkable tube bundling the first tube and the second tube, and a third tube in contact with an outer peripheral surface of the heat-shrinkable tube.

[0008] This configuration provides a suitable structure when the first tube and the second tube have properties that make them suitable for being bundled with heat-shrink tubing, and the third tube has properties that make them unsuitable for being bundled with heat-shrink tubing.

[0009] (2) In the medical device of the above aspect, a gap may be formed in the area surrounded by the outer circumferential surface of the first tube, the outer circumferential surface of the second tube, and the inner circumferential surface of the heat-shrinkable tube. With this configuration, the gap formed between the outer circumferential surface of the first tube, the outer circumferential surface of the second tube, and the inner circumferential surface of the heat-shrinkable tube can prevent the first tube and the second tube from restricting movement in a direction toward each other. As a result, the degree of freedom in the bending direction of the medical device can be improved.

[0010] (3) In the medical device of the above aspect, the heat-shrinkable tube may have a valley portion recessed toward the gap. With this configuration, the medical device can be made thinner than when the heat-shrinkable tube does not have the valley portion.

[0011] (4) In the medical device of the above aspect, the third tube may be in contact with the valley portion. With this configuration, the medical device can be made even thinner.

[0012] (5) In the medical device of the above aspect, the third tube may intersect with a common circumferential line of the outer circumferential surfaces of the first tube and the second tube. With this configuration, the outer diameter of the medical device can be further reduced.

[0013] (6) In the medical device of the above aspect, the melting point of the first tube may be higher than the melting point of the third tube.

[0014] (7) The medical device of the above aspect may further include a fourth tube that covers the heat-shrinkable tube and the third tube. With this configuration, the heat-shrinkable tube and the third tube can be bundled by the fourth tube.

[0015] (8) In the medical device of the above aspect, the first tube may have a lumen into which a sensor for acquiring image information is inserted. With this configuration, the medical device can perform a procedure using image information (ultrasound images) acquired from the sensor.

[0016] (9) In the medical device of the above aspect, the first tube may include a first distal tube and a first proximal tube disposed proximally of the first distal tube, the second tube may include a second distal tube and a second proximal tube disposed proximally of the second distal tube, and the heat-shrinkable tube may bundle the first proximal tube and the second proximal tube. With this configuration, by using tubes (e.g., PEEK tubes) that are more rigid and have a higher melting point than the third tube as the first proximal tube and using tubes (e.g., PEEK tubes) that are more flexible than the first and second proximal tubes and have a lower melting point as the first distal tube and second distal tube, it is possible to improve the torque transmission capability of the medical device while maintaining the flexibility of the distal end of the medical device.

[0017] (10) According to one aspect of the present invention, a method for manufacturing a medical device is provided. The method includes bundling a first tube and a second tube using a heat-shrinkable tube, contacting a third tube with the outer surface of the heat-shrinkable tube, and covering the heat-shrinkable tube and the third tube with a fourth tube. This manufacturing method allows the step of bundling the first tube and the second tube (heat-shrinkable tube arrangement step) and the step of bundling the third tube (fourth tube arrangement step) to be performed separately. In other words, this manufacturing method allows the first, second, and third tubes to be integrated even when it is difficult to bundle the first, second, and third tubes at the same time due to factors such as the properties of the first, second, and third tubes. Furthermore, the strength of the medical device can be improved compared to bundling the first, second, and third tubes at the same time.

[0018] (11) The method for manufacturing a medical device according to the above aspect may further include bundling the first tube and the second tube with the heat-shrinkable tube, and then covering the heat-shrinkable tube, the first tube exposed at the proximal end of the heat-shrinkable tube, and the second tube exposed at the proximal end of the heat-shrinkable tube with a fifth tube. This manufacturing method allows the first and second tubes exposed at the proximal end of the heat-shrinkable tube to be covered with the fifth tube along with the heat-shrinkable tube. This improves the strength of the portion of the medical device covered with the fifth tube.

[0019] (12) In the method for manufacturing a medical device according to the above aspect, covering with the fourth tube may include covering with the fourth tube the heat-shrinkable tube, the first tube exposed at the tip of the heat-shrinkable tube, the second tube exposed at the tip of the heat-shrinkable tube, and the third tube. According to this manufacturing method, the first and second tubes exposed at the tip of the heat-shrinkable tube can be covered together with the third tube by the fourth tube. As a result, the strength of the portion of the medical device covered with the fourth tube can be improved.

[0020] (13) In the method for manufacturing a medical device according to the above aspect, after covering with the fifth tube, covering with the fourth tube may be performed, wherein covering with the fifth tube includes welding the fifth tube at a first temperature, wherein the melting point of the third tube is lower than the melting point of the first tube, and covering with the fourth tube may include arranging a proximal end of the fourth tube more distal than the distal end of the fifth tube, and then welding the fourth tube at a second temperature lower than the first temperature. According to this manufacturing method, by setting the welding temperature (second temperature) in the step of covering with the fourth tube (fourth tube positioning step) lower than the welding temperature (first temperature) in the step of covering with the fifth tube (fifth tube positioning step), when a third tube having a melting point lower than the melting point of the first tube is used in the step of covering with the fourth tube, thermal deformation of the third tube can be suppressed.

[0021] 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.

[0022] 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 cross-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 a catheter near a heat-shrinkable tube. FIG. 6 is a cross-sectional view of a catheter taken along line F-F in FIG. 6. FIG. 6 is a diagram illustrating a method of manufacturing a catheter. FIG. 6 is a cross-sectional view of a catheter of a second embodiment. FIG. 6 is a cross-sectional view of a catheter of a third embodiment. FIG. 6 is an enlarged view of a portion of a catheter of a fourth embodiment near a heat-shrinkable tube.

[0023] 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."

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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 (shown by a broken line) is formed inside the OTW tube 20 for accommodating a treatment device (e.g., a plasma guidewire or a penetration guidewire). The OTW lumen 20L does not have a proximal opening in the portion that is placed inside the biological lumen when the catheter 1 is in use. The OTW lumen 20L is an over-the-wire (OTW) type lumen.

[0031] 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.

[0032] 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.

[0033] The RX tube 30 is a cylindrical member (tubular body) having a long 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 horse wire is formed inside the RX tube 30. The work horse wire is a guide wire that is inserted near the lesion prior to the catheter 1 in order to deliver the catheter 1.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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. These relationships between the outer diameter and the inner diameter are merely examples and may be changed as desired.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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. The first outer tube 50 and the second outer tube 80 may be made of the same material or different materials.

[0056] 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. The catheter 1 may also be used in a retrograde approach, or for procedures other than recanalization of a CTO.

[0057] (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.

[0058] 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." The OTW tube 20 (the distal tube 21 and the proximal tube 22) corresponds to the "second tube." The RX tube 30 corresponds to the "third tube." The first outer tube 50 corresponds to the "fourth tube." The second outer tube 80 corresponds to the "fifth tube." The heat-shrinkable tube 90 corresponds to the "heat-shrinkable tube." Furthermore, the distal tube 11 corresponds to the "first distal tube," and the proximal tube 12 corresponds to the "first proximal tube." The distal tube 21 corresponds to the "second distal tube," and the proximal tube 22 corresponds to the "second proximal tube." The sensor lumen 10L corresponds to the "lumen." In this embodiment, "same" and "equal" do not necessarily mean exact agreement, but rather mean allowing for differences due to manufacturing errors, etc. Furthermore, "constant" is synonymous with "generally constant," meaning that something is generally constant while allowing for variations due to manufacturing errors, etc.

[0059] Figure 6 is an enlarged view of a portion of the catheter 1 near the heat-shrinkable tube 90. Figure 7 is a cross-sectional view of the catheter 1 taken along line F-F in Figure 6. The relationship between the three tubes 10, 20, 30 and the three tubes 90, 50, 80 will be further described using Figures 6 and 7.

[0060] The distal end of the proximal tube 12 of the sensor tube 10 (first tube) is formed with a tapered portion 121 in which the outer diameter of the proximal tube 12 decreases from the proximal end toward the distal end. The tapered portion 121 is covered by the proximal end of the distal tube 11. In other words, the distal tube 11 and the proximal tube 12 are arranged to overlap within the tapered portion 121. In the example of FIG. 6 , the proximal position of the distal tube 11 is the same as the distal position of the heat-shrinkable tube 90. Similarly, the distal end of the proximal tube 22 of the OTW tube 20 (second tube) is formed with a tapered portion 221 in which the outer diameter of the proximal tube 22 decreases from the proximal end toward the distal end. However, the tapered shape of the tapered portion 221 is not shown in FIG. 6 . The tapered shape of the tapered portion 221 is shown in FIG. 8 . The tapered portion 221 is covered by the proximal end of the distal tube 21. In other words, the distal tube 21 and the proximal tube 22 are arranged to overlap in the area where the tapered portion 221 is provided. In Figure 6, the proximal position of the distal tube 21 is indicated by a dashed line extending in the Y-axis direction on the OTW tube 20.

[0061] 6 , the distal end position of the proximal tube 12 of the sensor tube 10 (the distal end position of the tapered portion 121) is different from the distal end position of the proximal tube 22 of the OTW tube 20 (the distal end position of the tapered portion 221). The distal end position of the proximal tube 22 of the OTW tube 20 is located closer to the distal end than the distal end position of the proximal tube 12 of the sensor tube 10.

[0062] Here, sections S1, S2, and S3 along the longitudinal direction of the catheter 1 are defined. Section S1 is a section from the first marker 41 to the proximal end of the RX tube 30. Section S2 is a section from the tip of the proximal tube 22 of the OTW tube 20 (the tip of the tapered portion 221) to the tip of the first reinforcing member 61. Section S3 is a section from the tip of the proximal tube 22 of the OTW tube 20 (the tip of the tapered portion 221) to the proximal end of the RX tube 30. Section S1 is a section in which the distal tube 11, the distal tube 21, and the RX tube 30, which are made of a flexible material such as the above-mentioned polyethylene resin, are present. Section S1 is a region in which the rigidity of the catheter 1 is relatively low. Section S1 is a region in which the melting points of the components of the catheter 1 are relatively low. Section S2 is a section including the proximal tube 12 and the proximal tube 22, which are made of a highly rigid material such as the PEEK resin. Section S2 is a region where the rigidity of the catheter 1 is relatively high. Section S2 is a region where the melting points of the components of the catheter 1 are relatively high.

[0063] Section S3 is an overlapping section between sections S1 and S2. In other words, section S3 is a section where the distal tube 11 and the RX tube 30, which have low rigidity and a low melting point, coexist with the proximal tube 12 and the proximal tube 22, which have high rigidity and a high melting point. Therefore, if processing suitable for either section S1 or section S2 is performed in section S3, unintended variations in the outer diameter and physical properties of the catheter 1 may occur, as well as poor appearance. For example, if processing suitable for section S1 is performed in section S3, poor bonding may occur in the proximal tube 12 and the proximal tube 22, which have high rigidity and a high melting point. Furthermore, if processing suitable for section S2 is performed in section S3, the distal tube 11 and the RX tube 30, which have low rigidity and a low melting point, may be deformed by heat. In this regard, the catheter 1 of this embodiment uses a heat-shrinkable tube 90 to solve these problems.

[0064] As shown in FIG. 6 , the heat-shrinkable tube 90 bundles a distal portion of the proximal tube 12 of the sensor tube 10 (first tube) and a distal portion of the proximal tube 22 of the OTW tube 20 (second tube). As shown in FIG. 7 (F-F cross section), the sensor tube 10 and the OTW tube 20 are covered by the heat-shrinkable tube 90 with portions of their outer circumferential surfaces 12o, 22o in contact with each other. A gap SP is formed in the area surrounded by the outer circumferential surfaces 12o, 22o of the sensor tube 10 and the OTW tube 20 and the inner circumferential surface 90i of the heat-shrinkable tube 90. The gap SP exists on both sides of the contact portion between the tubes 10 and 20. As shown in FIG. 7 , the heat-shrinkable tube 90 has a valley 92 recessed toward one of the gaps SP (specifically, the gap SP closer to the RX tube 30).

[0065] As shown in Fig. 7 , the RX tube 30 (third tube) is disposed in contact with a valley portion 92 in the outer peripheral surface of the heat-shrinkable tube 90. The valley portion 92 of the heat-shrinkable tube 90 is formed by pressing the RX tube 30 from the outer peripheral surface of the heat-shrinkable tube 90 toward the gap SP. In Fig. 7 , of the common circumferential tangents between the outer peripheral surface 12o of the sensor tube 10 and the outer peripheral surface 22o of the OTW tube 20, the common circumferential tangent EC on the RX tube 30 side is shown by a dashed line. In the cross section shown in Fig. 7 , the RX tube 30 intersects this common circumferential tangent EC.

[0066] 7, in the portion where the heat-shrinkable tube 90 and the first outer tube 50 overlap, the first outer tube 50 covers the heat-shrinkable tube 90 and the RX tube 30 that is disposed in contact with the outer peripheral surface of the heat-shrinkable tube 90. The outer peripheral surfaces of the heat-shrinkable tube 90 and the RX tube 30 are integrally fixed by the melt-molded first outer tube 50.

[0067] 8 and 9 are diagrams illustrating a manufacturing method of the catheter 1. In Figures 8 and 9, the first outer tube 50 is indicated by thin diagonal hatching, the second outer tube 80 is indicated by thick diagonal hatching, and the heat-shrinkable tube 90 is indicated by dotted hatching. In Figures 8 and 9, components whose shapes change due to heating or the like in the manufacturing process are indicated by the suffix "a" added to the reference numerals before the change.

[0068] 8A shows the proximal tube placement step. As shown in FIG. 8A, the worker places the proximal tube 12, which has a tapered portion 121 at its distal end, and the proximal tube 22, which has a tapered portion 221 at its distal end, with their distal ends offset from each other. A mandrel C is inserted inside each of the tubes 12 and 22.

[0069] 8B illustrates the heat-shrink tube arrangement step. As shown in FIG. 8B , the worker bundles the proximal tube 12 (first tube) and the proximal tube 22 (second tube) using the heat-shrink tube 90a. Specifically, the worker covers the proximal tube 12 and the proximal tube 22 with the heat-shrink tube 90a. At this time, the worker positions the distal end of the heat-shrink tube 90a at the proximal end of the tapered portion 121 of the proximal tube 12. By performing the heat-shrink tube arrangement step in this manner prior to the fifth tube arrangement step and the fourth tube arrangement step, the proximal tube 12 and the proximal tube 22 can be temporarily fastened together with the heat-shrink tube 90a, thereby preventing misalignment of the tubes.

[0070] FIG. 8C illustrates the fifth tube placement process. As shown in FIG. 8C, the worker covers the proximal end of the heat-shrinkable tube 90a and the proximal tube 12 (first tube) and the proximal tube 22 (second tube) exposed at the proximal end of the heat-shrinkable tube 90a with the second outer tube 80a (fifth tube). The worker then heats the area indicated by the white arrow where the heat-shrinkable tube 90a and the second outer tube 80a are located at a first temperature TE1. The first temperature TE1 is a temperature at which the proximal tube 12 and the proximal tube 22 do not deform and the second outer tube 80a melts. The heating shrinks the proximal end of the heat-shrinkable tube 90a. The heating also welds the second outer tube 80a to the heat-shrinkable tube 90a and the tubes 12 and 22, forming a melt-molded thick-walled portion ( FIG. 3E ). Prior to heating, the worker covers the second outer tube 80a with a heat-shrinkable molding tube, and removes the heat-shrinkable molding tube after heating (melting).

[0071] 8(D) shows the distal tube placement step. As shown in FIG. 8(D), the operator inserts the distal tube 11a into the core C and slides the proximal end of the distal tube 11a until it is flush with the proximal end of the tapered portion 121. Similarly, the operator inserts the distal tube 21a into the core C and slides the proximal end of the distal tube 21a until it is flush with the proximal end of the tapered portion 221.

[0072] 9A shows the step of placing the RX tube 30a in the fourth tube placement step. As shown in FIG. 9A, the worker prepares the RX tube 30a with the mandrel C inserted therein. Then, the worker aligns the base end of the RX tube 30a so that it overlaps with the heat-shrink tube 90a (in other words, closer to the base end than the tapered portion 121), and places the RX tube 30a (third tube) in contact with the outer circumferential surface of the heat-shrink tube 90a, as shown in the balloon.

[0073] 9B illustrates the step of placing the first outer tube 50a in the fourth tube placement step. As shown in FIG. 9B, the worker covers the distal end of the heat-shrinkable tube 90a, the distal tube 11a (first tube), the distal tube 21a (second tube), and the RX tube 30a (third tube) exposed at the distal end of the heat-shrinkable tube 90a with the first outer tube 50a (fourth tube). The worker then heats the area indicated by the hatched arrow where the heat-shrinkable tube 90a and the first outer tube 50a are placed at a second temperature TE2. The second temperature TE2 is lower than the first temperature TE1 in the fifth tube placement step. The second temperature TE2 is a temperature at which the distal tube 11a, the distal tube 21a, and the RX tube 30a do not deform and the first outer tube 50a melts. The heating shrinks the tip of the heat-shrinkable tube 90a. The heating also welds the first outer tube 50a to the heat-shrinkable tube 90a and the tubes 11a, 21a, and 30, forming a melt-formed thick-walled portion (FIGS. 3C, 3D, and 7). Prior to heating, the worker covers the first outer tube 50a with a heat-shrinkable tube for molding, and removes the heat-shrinkable tube for molding after heating (melting).

[0074] Thereafter, the worker diagonally cuts the proximal end of the RX tube 30 and the first outer tube 50 covering that portion to create a proximal end opening 302. As shown in FIG. 9B , a distal end position 501 of the first outer tube 50 (fourth tube) is closer to the distal end than a distal end position 901 of the heat-shrinkable tube 90. A proximal end position 802 of the second outer tube 80 (fifth tube) is closer to the proximal end than the proximal end position 902 of the heat-shrinkable tube 90. In addition, the proximal end position 502 of the first outer tube 50 (fourth tube) is closer to the distal end than the distal end position 801 of the second outer tube 80 (fifth tube).

[0075] As described above, a suitable structure can be provided when the sensor tube 10 (specifically, the proximal tube 12) as the first tube and the OTW tube 20 (specifically, the proximal tube 22) as the second tube have properties suitable for being bundled with the heat-shrinkable tube 90, and the RX tube 30 (specifically, the third tube) has properties unsuitable for being bundled with the heat-shrinkable tube 90. That is, according to this configuration, a suitable structure can be provided when the catheter 1 has a section in which the distal tube 11 and the RX tube 30, which have low rigidity and low melting point, and the proximal tube 12 and the proximal tube 22, which have high rigidity and high melting point, are mixed, as in section S3 described in Fig. 6 .

[0076] Furthermore, a gap SP is formed in the area surrounded by the outer circumferential surface 12o of the sensor tube 10 (first tube), the outer circumferential surface 22o of the OTW tube 20 (second tube), and the inner circumferential surface 90i of the heat-shrinkable tube 90 ( FIG. 7 ). This gap SP prevents restriction of movement of the sensor tube 10 and the OTW tube 20 in the direction D1 (the direction indicated by the bold arrow in FIG. 7 ) in which the sensor tube 10 and the OTW tube 20 are adjacent to each other during use of the catheter 1. Specifically, when a bending force is applied in the direction D1 during use of the catheter 1, the sensor tube 10 and the OTW tube 20 can slide over each other's outer circumferential surfaces 12o, 22o within the heat-shrinkable tube 90. As a result, the degree of freedom in the bending direction of the catheter 1 (medical device) can be improved.

[0077] Furthermore, because the heat-shrinkable tube 90 has valleys 92, the catheter 1 (medical device) is thinner than when the heat-shrinkable tube 90 does not have the valleys 92 (FIG. 7). Furthermore, because the RX tube 30 (third tube) is in contact with the valleys 92, the catheter 1 (medical device) is even thinner (FIG. 7). Furthermore, because the RX tube 30 (third tube) intersects with the common circumferential tangent EC of the outer circumferential surface 12o of the sensor tube 10 (first tube) and the outer circumferential surface 22o of the OTW tube 20 (second tube), the catheter 1 (medical device) is even thinner (FIG. 7).

[0078] Furthermore, since the first outer tube 50 (fourth tube) that covers the heat shrink tube 90 and the RX tube 30 (third tube) is provided, the heat shrink tube 90 and the RX tube 30 can be bundled by the first outer tube 50. Furthermore, since the sensor tube 10 (first tube) has a sensor lumen 10L (first lumen) into which the sensor 70 that acquires image information is inserted, a procedure can be performed using the catheter 1 (medical device) using image information (ultrasound image) acquired from the sensor 70 (FIGS. 4 and 5).

[0079] Furthermore, the process of bundling the sensor tube 10 (specifically, the proximal tube 12) as the first tube and the OTW tube 20 (specifically, the proximal tube 22) as the second tube (heat-shrink tube arranging process: FIG. 8B ) and the process of bundling the RX tube 30a as the third tube (fourth tube arranging process: FIGS. 9A and 9B ) can be performed separately. In other words, according to the first embodiment, even if it is difficult to simultaneously bundle the first, second, and third tubes 10, 20, and 30 due to factors such as the properties of the first, second, and third tubes 10, 20, and 30, the first, second, and third tubes 10, 20, and 30 can be integrated. Furthermore, the strength of the catheter 1 (medical device) can be improved compared to when the first, second, and third tubes 10, 20, and 30 are simultaneously bundled.

[0080] Furthermore, the first and second tubes 10, 20 (specifically, the proximal tube 12 and the proximal tube 22) exposed from the proximal end of the heat-shrinkable tube 90a can be covered together with the heat-shrinkable tube 90a by the second outer tube 80a, which serves as a fifth tube (FIG. 8(C)). As a result, the strength of the portion of the catheter 1 (medical device) covered by the second outer tube 80 can be improved.

[0081] Furthermore, the first and second tubes 10, 20 (specifically, the distal tube 11a and the distal tube 21a) exposed from the distal end of the heat-shrinkable tube 90a can be covered together with the heat-shrinkable tube 90a, the RX tube 30a (third tube), and the first outer tube 50a (fourth tube) (FIGS. 9A and 9B). As a result, the strength of the portion of the catheter 1 (medical device) covered by the first outer tube 50 can be improved.

[0082] Furthermore, by setting the welding temperature (second temperature TE2) in the process of covering with the fourth tube (fourth tube placement process) lower than the welding temperature (first temperature TE1) in the process of covering with the fifth tube (fifth tube placement process), when an RX tube 30a (third tube) having a melting point lower than the melting point of the sensor tube 10 (specifically, the base end tube 12) as the first tube is used in the process of covering with the fourth tube, deformation of the RX tube 30a due to heat can be suppressed.

[0083] <Second embodiment> Figure 10 is a cross-sectional view of a catheter 1A of a second embodiment. Figure 10 shows a cross-section of the catheter 1A taken along line F-F in Figure 6. The catheter 1A of the second embodiment has the same configuration as the first embodiment, except that it includes a heat-shrinkable tube 90A instead of the heat-shrinkable tube 90.

[0084] As shown in FIG. 10 (F-F cross section), the heat-shrinkable tube 90A has a convex portion 93 and a concave portion 94 in addition to the valley portion 92 described in the first embodiment. The convex portion 93 is a portion of the heat-shrinkable tube 90A that protrudes toward the other gap SP (specifically, the gap SP on the side farther from the RX tube 30). The concave portion 94 is a portion of the heat-shrinkable tube 90A that is recessed toward the contact portion of the tubes 10 and 20 on the opposite side (outer peripheral surface side) of the convex portion 93. Also, as shown in FIG. 10 , in the second embodiment, the RX tube 30 (third tube) is in contact with the outer peripheral surface of the heat-shrinkable tube 90A but is not in contact with the valley portion 92. That is, a gap SP1 is provided between the outer peripheral surface of the RX tube 30 and the valley portion 92.

[0085] As described above, the shape of the heat-shrinkable tube 90A can be modified in various ways. Additionally, the sensor tube 10 and the OTW tube 20 may not be in contact with each other inside the heat-shrinkable tube 90A, and their outer peripheral surfaces 12o, 22o may be spaced apart. The inner peripheral surface 90i of the heat-shrinkable tube 90A and the outer peripheral surface 12o of the sensor tube 10 may not be in contact with each other, and may be spaced apart. Furthermore, the inner peripheral surface 90i of the heat-shrinkable tube 90A and the outer peripheral surface 22o of the OTW tube 20 may not be in contact with each other, and may be spaced apart. Furthermore, the gap SP does not have to be formed in the region between the inner peripheral surface 90i of the heat-shrinkable tube 90A and the outer peripheral surfaces 12o, 22o of the sensor tube 10 and the OTW tube 20. The catheter 1A of the second embodiment described above can also achieve the same effects as those of the first embodiment described above.

[0086] <Third embodiment> Figure 11 is a cross-sectional view of a catheter 1B of a third embodiment. Figure 11 shows a cross-section of the catheter 1B taken along line F-F in Figure 6. The catheter 1B of the third embodiment includes a heat-shrinkable tube 90B instead of the heat-shrinkable tube 90 in the configuration described in the first embodiment.

[0087] 11 (F-F cross section), the heat shrink tube 90B does not have the valley portion 92 described in the first embodiment. As shown in Fig. 11, in the third embodiment, the RX tube 30 (third tube) is in contact with the outer peripheral surface of the heat shrink tube 90B, but is not in contact with the valley portion 92. In addition, the RX tube 30 does not intersect with the common external tangent line EC of the outer peripheral surface 12o of the sensor tube 10 and the outer peripheral surface 22o of the OTW tube 20.

[0088] As described above, the shape of the heat-shrinkable tube 90B can be modified in various ways. Additionally, the outer peripheral surfaces 12o and 22o may be spaced apart from each other inside the heat-shrinkable tube 90B, and the inner peripheral surface 90i and the outer peripheral surface 12o (or the outer peripheral surface 22o) may be spaced apart and not in contact with each other. Furthermore, the gap SP may not be formed in the region between the inner peripheral surface 90i and each of the outer peripheral surfaces 12o and 22o. The catheter 1B of the third embodiment described above can also achieve the same effects as those of the first embodiment described above.

[0089] 12 is an enlarged view of a portion of a catheter 1C according to a fourth embodiment, near a heat-shrinkable tube 90. The catheter 1C according to the fourth embodiment does not include the first outer tube 50 and the second outer tube 80 in the configuration described in the first embodiment.

[0090] As shown in the left-hand bubble in the lower part of Fig. 12, in the catheter 1C, the distal tube 11, the distal tube 21, and the heat-shrinkable tube 90 are joined together with a bonding agent GE. As shown in the right-hand bubble in the lower part of Fig. 12, in the catheter 1C, the proximal tube 12 and the proximal tube 22 are joined together with a bonding agent GE. Any bonding agent can be used as the bonding agent GE, for example, metal solder such as silver solder, gold solder, zinc, Sn-Ag alloy, or Au-Sn alloy, or an adhesive such as an epoxy adhesive. Alternatively, bonding by thermal welding may be employed without using the bonding agent GE.

[0091] As described above, the configuration of the catheter 1C can be modified in various ways, and the catheter 1C may be configured without at least one of the first outer tube 50 (fourth tube) and the second outer tube 80 (fifth tube). The catheter 1C of the fourth embodiment as described above can also achieve the same effects as those of the first embodiment.

[0092] <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.

[0093] [Modification 1] In the above first to fourth embodiments, one example of the configuration of the catheters 1, 1A to 1C is shown. The configuration of the catheters 1, 1A to 1C can be modified in various ways.

[0094] For example, the outer peripheral surfaces of the first outer tube 50, the heat-shrinkable tube 90, and the second outer tube 80, or the outer peripheral surface of the catheter 1 including these, may be coated with a hydrophilic resin or a hydrophobic resin. 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. 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.

[0095] 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).

[0096] 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.

[0097] 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).

[0098] 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.

[0099] For example, the manufacturing method of the catheters 1, 1A-1C described in Figures 8 and 9 is merely an example, and various modifications are possible. For example, after the heat shrink tube placement step, the fourth tube placement step may be performed, and then the fifth tube placement step may be performed. For example, additional steps may be performed between the above-described steps, such as pre-processing for processing or for placing other components not described. Furthermore, for example, in the case of manufacturing the catheter 1C of the fourth embodiment, the fourth tube placement step and the fifth tube placement step may be omitted.

[0100] [Modification 2] The configurations of the catheters 1, 1A to 1C of the first to fourth embodiments and the configuration of the catheters 1, 1A to 1C of Modification 1 may be combined as appropriate. For example, the configuration of the fourth embodiment may be combined with heat-shrinkable tubes 90A, 90B having the shapes described in the second or third embodiment.

[0101] 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, The first tube and, The second tube and A heat-shrinkable tube that bundles the first tube and the second tube together, A third tube that contacts the outer surface of the heat shrinkable tube, A medical device equipped with the following features.

2. A medical device according to claim 1, A medical device having a void in the region surrounded by the outer surface of the first tube, the outer surface of the second tube, and the inner surface of the heat-shrinkable tube.

3. A medical device according to claim 2, A medical device in which the heat-shrinkable tube has a groove that is recessed toward the void.

4. A medical device according to claim 3, The third tube is a medical device in contact with the valley portion.

5. A medical device according to any one of claims 1 to 4, A medical device in which the third tube intersects with the common outer tangent line between the outer surface of the first tube and the outer surface of the second tube.

6. A medical device according to any one of claims 1 to 4, A medical device in which the melting point of the first tube is higher than the melting point of the third tube.

7. A medical device according to any one of claims 1 to 4, further, A medical device comprising the heat-shrinkable tube and a fourth tube that covers the third tube.

8. A medical device according to any one of claims 1 to 4, The first tube is a medical device having a lumen into which a sensor for acquiring image information is inserted.

9. A medical device according to any one of claims 1 to 4, The first tube comprises a first tip tube and a first proximal tube positioned closer to the proximal end than the first tip tube. The second tube comprises a second tip tube and a second proximal tube positioned closer to the proximal end than the second tip tube. The heat-shrinkable tube bundles the first proximal end tube and the second proximal end tube together in this medical device.

10. A method for manufacturing a medical device, The first tube and the second tube are bundled together using heat shrink tubing. The third tube is brought into contact with the outer surface of the heat shrink tube. The heat shrinkable tube and the third tube are covered with the fourth tube. A method for manufacturing medical devices, including the following.

11. A method for manufacturing a medical device according to claim 10, further, A method for manufacturing a medical device, comprising bundling the first tube and the second tube using the heat shrink tubing, and then covering the heat shrink tubing, the first tube exposed from the base end of the heat shrink tubing, and the second tube exposed from the base end of the heat shrink tubing with a fifth tube.

12. A method for manufacturing a medical device according to claim 10 or claim 11, A method for manufacturing a medical device, comprising covering with the fourth tube, covering the heat shrinkable tube, the first tube exposed from the tip of the heat shrinkable tube, the second tube exposed from the tip of the heat shrinkable tube, and the third tube.

13. A method for manufacturing a medical device according to claim 11, After covering with the fifth tube, the fourth tube is then used to cover the area. Covering with the fifth tube includes welding the fifth tube at the first temperature, The melting point of the third tube is lower than the melting point of the first tube. A method for manufacturing a medical device, comprising covering with the fourth tube, positioning the base end of the fourth tube further forward than the tip of the fifth tube, and then welding the fourth tube at a second temperature lower than the first temperature.