Medical device and method for manufacturing medical device

Abstract

This medical device is provided with: a distal end tip; a first tube having a first lumen, the distal end of the first tube being positioned further to the distal end side than the proximal end of the distal end tip and on the inner peripheral side of the distal end tip; and a second tube having a second lumen and being in contact with the distal end tip.

Description

Medical device and method for manufacturing medical device

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

[0002] Patent Literature 1 describes a medical device including a transducer unit for transmitting and receiving ultrasound waves to and from biological tissue, an imaging lumen for enabling movement of the transducer unit and a drive shaft, and a guidewire lumen for allowing insertion of a guidewire. Hereinafter, the ultrasound image acquisition mechanism including the drive shaft and 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] In a medical device having an ultrasound image acquisition function, multiple lumens are provided 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, a second tube is joined to the distal end of a first tube, so there is a risk that the second tube will fall off if the joining strength between the first and second tubes is insufficient or depending on the state of use of the medical device.

[0005] This problem is not limited to medical devices with built-in sensors (i.e., devices that themselves have the function of acquiring ultrasound images), 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 system, digestive system, secretory glands, and reproductive organs.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and has an object to improve the bonding strength of a plurality of tubes in a medical device having a plurality of 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 distal tip; a first tube having a first lumen, the distal end of which is located distally of and on the inner circumferential side of the proximal end of the distal tip; and a second tube having a second lumen and in contact with the distal tip.

[0009] With this configuration, the distal end of the first tube is located distal to the proximal end of the distal tip and on the inner periphery of the distal tip, and the second tube is in contact with the distal tip, so that both the first tube and the second tube can be fixed using the distal tip, thereby improving the joining strength between the first and second tubes compared to joining the first and second tubes without using the distal tip.

[0010] (2) The medical device of the above aspect may further include a radiopaque marker provided on the second tube, the marker being disposed in at least a portion of a longitudinal section of the medical device from the distal end of the first tube to the proximal end of the distal tip. With this configuration, the marker makes it possible to grasp the position of the distal tip.

[0011] (3) In the medical device of the above embodiment, the marker may be a first marker, and a second marker having radiopacity may be provided at a position closer to the proximal end than the first marker and spaced apart from the first marker. With this configuration, the two markers (the first marker and the second marker) are spaced apart from each other in the longitudinal direction of the medical device, thereby improving the visibility of the medical device under X-ray images (angiography images).

[0012] (4) The medical device of the above aspect may further include a third tube having a third lumen, the third tube having a distal end opening communicating the distal end of the third lumen with the outside, the distal end opening being located near the second marker. With this configuration, the position of the distal end opening of the third lumen can be ascertained by the second marker.

[0013] (5) In the medical device of the above aspect, the distal tip may have a first layer and a second layer covering the first layer, the distal end of the first layer being located proximal to the distal end of the second layer, and both the first layer and the second layer being radiopaque. This configuration can improve the visibility of the distal tip under X-ray images in the overlapping portion of the first layer and the second layer. Furthermore, in this configuration, if a first marker is disposed in the section from the distal end of the first tube to the proximal end of the distal tip, the visibility of the distal tip under X-ray images can be further improved in the overlapping portion of the first layer, the second layer, and the first marker.

[0014] (6) In the medical device of the above aspect, the cross-sectional shape of the proximal end of the distal tip may be symmetrical about 360 degrees. According to this configuration, the distal tip has a cross-sectional shape that is symmetrical about 360 degrees at the proximal end, which makes it easier for the surgeon to bend the medical device in the direction intended by the surgeon during a procedure using the medical device.

[0015] (7) In the medical device of the above aspect, the outer periphery of the distal tip may have a generally elliptical shape in the cross section, with the major axis intersecting the first tube and the minor axis not intersecting the first tube. This configuration allows the medical device to be easily bent in the minor axis direction of the outer periphery of the distal tip.

[0016] (8) According to one aspect of the present invention, a method for manufacturing a medical device is provided. This method includes: arranging a first tube having a first mandrel inserted therein and a second tube having a second mandrel inserted therein such that the distal end of the first mandrel is located proximal to the distal end of the first tube; covering the area from the distal end of the first tube to the distal end of the first mandrel with a heat-shrinkable tube; and using heat shrinkage of the heat-shrinkable tube to form a distal end portion of the first tube that closes the lumen within the first tube and extends along the outer circumferential surface of the second tube distal to the closed end. This manufacturing method allows the distal end of the first tube to be formed with a shape suitable for fixation using a distal tip. Furthermore, in the positioning step, the length of the distal end portion can be controlled by adjusting the distal positions of the first mandrel and the first tube.

[0017] (9) In the method for manufacturing a medical device according to the above aspect, the heat-shrinkable tube may be a first heat-shrinkable tube, and after forming the distal end portion, the distal end portion and the second tube may be covered with a cylindrical member made of resin, the cylindrical member may be covered with a second heat-shrinkable tube, and the cylindrical member may be fixed to the distal end portion of the first tube and the second tube by utilizing the heat shrinkage of the second heat-shrinkable tube. According to this manufacturing method, the distal end portion of the first tube and the second tube are sandwiched and fixed using the second core bar and the cylindrical member, thereby enabling the first tube and the second tube to be firmly fixed together.

[0018] (10) In the method for manufacturing a medical device according to the above aspect, the cylindrical member may be a first cylindrical member, the first cylindrical member may be covered with a second cylindrical member made of resin, the second cylindrical member may be welded to the first cylindrical member, and the distal end of the second cylindrical member may be tapered to form a distal tip. This manufacturing method allows for the formation of a distal tip with a two-layer structure.

[0019] 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.

[0020] FIG. 1 is an explanatory diagram illustrating the configuration of a medical device. FIG. 1 is an explanatory diagram illustrating the configuration of a medical device. FIG. 2 is a transverse sectional view of a catheter. FIG. 3 is a diagram illustrating a method of using a catheter. FIG. 4 is a diagram illustrating a method of using a catheter. FIG. 5 is an enlarged view of the tip end side of a catheter. FIG. 6 is a transverse sectional view of constituent members of a catheter. FIG. 7 is a diagram illustrating a method of manufacturing a catheter. FIG. 8 is a diagram illustrating a method of manufacturing a catheter. FIG. 9 is an enlarged view of the tip end side of a catheter of a second embodiment. FIG. 10 is an enlarged view of the tip end side of a catheter of a third embodiment. FIG. 11 is an enlarged view of the tip end side of a catheter of a fourth embodiment. FIG. 12 is a transverse sectional view of a catheter of a fifth embodiment.

[0021] 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. Hereinafter, the medical device 1 will also be referred to as a "catheter 1." The catheter 1 is used to treat a lesion in a biological lumen, such as a CTO (Cardiac Tissue Occurring in a blood vessel). 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."

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 may be colored so that it can be directly viewed by the surgeon. In this way, by arranging 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. The first marker 41 is also simply referred to as a "marker."

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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 the rigidity of the catheter 1 (reducing the rigidity 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.

[0050] 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.

[0051] 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.

[0052] 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. 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.

[0053] 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.

[0054] 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.

[0055] (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.

[0056] 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 RX tube 30 corresponds to the "second tube." The OTW tube 20 (the distal tube 21 and the proximal tube 22) corresponds to the "third tube." The sensor lumen 10L corresponds to the "first lumen," the RX lumen 30L corresponds to the "second lumen," and the OTW lumen 20L corresponds to the "third lumen." The distal opening 201 corresponds to the "distal opening." 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.

[0057] Figure 6 is an enlarged view of the distal end side of the catheter 1. Figure 7 is a cross-sectional view of the components of the catheter 1. Figure 7(A) shows a cross-section of the catheter 1 taken along line F-F in Figure 6, in other words, a cross-section of the catheter 1 at the base end of the distal tip 40. Figure 7(B) shows a cross-section of the second marker 42. The distal tip 40, first marker 41, and second marker 42 will be described in detail using Figures 6 and 7.

[0058] As shown in Figure 6, the distal tip 40 has a two-layer structure consisting of a first layer 410 and a second layer 420. The first layer 410 (inner layer) covers the distal end of the RX tube 30 (second tube) and the distal end 110 of the sensor tube 10 (first tube), fixing them together. The second layer 420 (outer layer) covers the first layer 410. The distal end 4101 of the first layer 410 is located closer to the proximal end than the distal end 4201 of the second layer 420. The proximal end 4102 of the first layer 410 is located at the same position as the proximal end 4202 of the second layer 420. The distal end 4201 of the second layer 420 corresponds to the "distal end of the distal tip," and the proximal end 4202 of the second layer 420 corresponds to the "proximal end of the distal tip."

[0059] The length L40 of the distal tip 40 in the longitudinal direction of the catheter 1 is equal to the length L420 of the second layer 420 (length L40 = L420). The length L420 of the second layer 420 is longer than the length L410 of the first layer 410 (length L420 < L410). Both the first layer 410 and the second layer 420 are radiopaque. The first layer 410 and the second layer 420 can be formed from the radiopaque resin material or radiopaque metal material described above as the material for the distal tip 40.

[0060] As shown in FIG. 7A , in the cross section of the catheter 1 at the proximal end of the distal tip 40, the RX tube 30 is positioned at the innermost position. The first marker 41 covers the RX tube 30 with the inner circumferential surface of the first marker 41 in contact with the outer circumferential surface of the RX tube 30. A distal end portion 110 extending along the outer circumferential surface of the RX tube 30 beyond the first marker 41 is provided on a portion of the outer circumferential surface of the first marker 41 (in the illustrated example, a portion of the outer circumferential surface in the +Y direction). As shown in FIGS. 6 and 7A , the distal end portion 110 is a thick-walled portion with a crescent-shaped cross section formed by melting a portion of the distal end side of the sensor tube 10, which would normally have a cylindrical cross section. As shown in FIG. 7A , no lumen exists inside the distal end portion 110. The first layer 410 covers the tip portion 110 and the first marker 41 with the inner circumferential surface of the first layer 410 in contact with the outer circumferential surface of the tip portion 110 and the outer circumferential surface of the first marker 41. The second layer 420 covers the first layer 410 with the inner circumferential surface of the second layer 420 in contact with the outer circumferential surface of the first layer 410.

[0061] 6 and 7A, the RX tube 30 (second tube) is in direct contact with the distal tip 40 at the portion where the first marker 41 is provided, beyond the first marker 41, and distally of the first marker 41, the distal tip 1101 of the sensor tube 10 (first tube) is located distally of the proximal end 4202 of the distal tip and on the inner circumferential side of the distal tip 40. A protruding portion 111, in which the wall of the tube is protruding, is formed in the sensor tube 10 proximal to the distal end 110. Inside the protruding portion 111, the sensor lumen 10L has a reduced diameter, and a distal opening 101 is formed at the end of the protruding portion 111 (the end farther from the RX tube 30 in the illustrated example) to allow fluid to pass between the inside and outside of the RX lumen 30L. The diameter of the distal end opening 101 is smaller than the diameter of the sensor 70 , and the sensor 70 cannot be inserted through the distal end opening 101 .

[0062] As shown in Figure 7 (A), the cross-sectional shape of the catheter 1 at the base end of the distal tip 40 is 360-degree symmetric. Here, "the cross-sectional shape of the catheter 1 is 360-degree symmetric" means that the outer circumferential contour of the distal tip 40 (specifically, the second layer 420) in the cross-section is 360-degree symmetric, or that the configuration of each component of the catheter 1 in the cross-section is 360-degree symmetric. Note that "360-degree symmetric" means that a symmetrical shape cannot be achieved without one full rotation. For this reason, a configuration in which each component of the catheter 1 has a circular cross-section and is stacked concentrically is not 360-degree symmetric (it is excluded from the concept of 360-degree symmetry). The catheter 1 of this embodiment has a cross-sectional shape that is symmetrical at 360 degrees at the base end of the distal tip 40 because the distal end 110 of the sensor tube 10 is included in a laminated structure, which results in uneven outer contour shapes and thicknesses of the first layer 410 and the second layer 420.

[0063] In the cross section shown in Fig. 7(A), the outline of the outer periphery of the distal tip 40 (specifically, the second layer 420) is substantially elliptical. Fig. 7(A) illustrates the center O of this ellipse, the major axis AL of the ellipse passing through the center O, and the minor axis AS of the ellipse passing through the center O. As shown in the figure, the major axis AL of the ellipse intersects with the sensor tube 10 (first tube), while the minor axis AS of the ellipse does not intersect with the sensor tube 10.

[0064] The first marker 41 is a radiopaque, annular member, and is disposed between the RX tube 30 and the first marker 41 (in other words, on the outer circumferential side of the RX tube 30 and the inner circumferential side of the first marker 41) as shown in FIG. 7(A). In the longitudinal direction of the catheter 1, the first marker 41 is disposed in at least a portion of the section from the distal end 1101 of the sensor tube 10 (first tube) to the proximal end 4202 of the distal tip. In the example of FIG. 6, the first marker 41 is disposed such that the distal end of the first marker 41 is located near the center of the distal end portion 110 and the proximal end of the first marker 41 is located at the proximal end 4202 of the distal tip. As a result, at the position where the first marker 41 is disposed, a triple layer of radiopaque members (the first marker 41, the first layer 410, and the second layer 420) is disposed.

[0065] The second marker 42 is a radiopaque, annular member and is arranged on the outer periphery of the RX tube 30, as shown in Fig. 6 . In the longitudinal direction of the catheter 1, the second marker 42 is arranged closer to the proximal end than the first marker 41 and at a position distant from the first marker 41. In the example of Fig. 6 , the second marker 42 is arranged so that the proximal end of the second marker 42 is located at the tip of the distal opening 201 (distal opening) of the OTW lumen 20L (third lumen). This allows the surgeon to recognize the distal position of the distal opening 201 from which the treatment device is to be protruded by referring to the position of the second marker 42 on the X-ray image.

[0066] As shown in Figure 6, the length L41 of the first marker 41 in the longitudinal direction of the catheter 1 is longer than the length L42 of the second marker 42 (length L41 > L42). Meanwhile, as shown in Figures 7A and 7B, the thickness T41 of the first marker 41 and the thickness T42 of the second marker 42 are the same (thickness T41 = T42). Note that if the first marker 41 or the second marker 42 does not have a constant length (for example, if the shape when viewed from the side is trapezoidal or triangular), the lengths L41 and L42 are the lengths of their longest portions. Similarly, if the first marker 41 or the second marker 42 has a non-uniform thickness, the thicknesses T41 and T42 are the thicknesses of their thickest portions.

[0067] The first marker 41 and the second marker 42 may have a shape other than a circular ring. For example, the first marker 41 and the second marker 42 may have a shape obtained by cutting a ring at an arbitrary angle or a linear shape. For example, the first marker 41 and the second marker 42 may have a coil shape obtained by spirally winding a wire. Furthermore, the first marker 41 and the second marker 42 may be disposed on a tube other than the RX tube 30 (for example, the sensor tube 10 or the OTW tube 20). The first marker 41 and the second marker 42 may be disposed on the same tube as described above, or may be disposed on different tubes.

[0068] 8 and 9 are diagrams illustrating the manufacturing method of the catheter 1. In FIGS. 8 and 9, the first and second cylindrical members are indicated by different types of diagonal hatching, and the heat-shrinkable tubes are indicated by dotted hatching. In FIGS. 8 and 9, components whose shapes change due to heating or other factors during the manufacturing process are designated by the suffix "a" before the change. The first to third heat-shrinkable tubes ST1 to ST3, which appear in the following description, are tubular bodies formed from thermoplastic nylon-based elastomer resin, polyolefin, FEP, silicone, or the like, and have the property of shrinking without melting when heated. The first and second cylindrical members 410a and 410b are tubular bodies formed from polyurethane resin containing tungsten, and, unlike the first to third heat-shrinkable tubes ST1 to ST3, have the property of melting when heated. The first and second cylindrical members 410a and 410b may be made of the various materials described above as materials for the distal tip 40. The first cylindrical member may also be simply referred to as the "cylindrical member."

[0069] 8A illustrates the arrangement process. As shown in FIG. 8A, the worker prepares a distal tube 11a (first tube) with a first core bar C1 inserted therein, an RX tube 30a (second tube) with a second core bar C2 inserted therein, and a distal tube 21a (third tube) with a third core bar C3 inserted therein. The worker then arranges the components so that the distal end P1 of the first core bar C1 is located closer to the base end than the distal end P2 of the distal tube 11a, and the distal end P2 of the distal tube 11a is located closer to the base end than the distal end P3 of the RX tube 30a. In the illustrated example, the distance from the distal end P3 to the distal end P1 is longer than the distance from the distal end P2 to the distal end P1. As illustrated, a first marker 41 and a second marker 42 are previously arranged on the RX tube 30a. The worker positions the distal end of the distal tube 21a so that the distal end is located closer to the base end than the distal end P1 of the first core C1. In the manufacturing method described with reference to Figures 8 and 9, the distal tube 21a (third tube) is not used and may be omitted.

[0070] 8B shows the state of the tip portion forming process before heating. As shown in FIG. 8B, the worker covers at least the area from the tip P2 of the tip-side tube 11a (first tube) to the tip P1 of the first core metal C1 with the first heat-shrinkable tube ST1. In the illustrated example, the first heat-shrinkable tube ST1 covers the area from the tip P3 of the RX tube 30a (second tube) to the tip P1 of the first core metal C1. The worker then heats at least the area from the tip P2 to the tip P1 at a first temperature. The first temperature is set to a temperature at which the first heat-shrinkable tube ST1 thermally shrinks and the tip-side tube 11a melts. The first heat-shrinkable tube is also simply referred to as the "heat-shrinkable tube."

[0071] FIG. 8C shows the state after heating during the distal end portion forming process. After heating, the operator removes the first heat-shrinkable tube ST1. As shown in FIG. 8C, the portion of the distal end tube 11a where the first core metal C1 is not inserted (i.e., the portion from tip P2 to tip P1) melts and is crushed as the first heat-shrinkable tube ST1 thermally shrinks, forming a distal end portion 110 extending along the outer circumferential surface of the RX tube 30a. As shown in the figure, the lumen within the distal end tube 11a (first tube) is closed at the distal end, and the distal end portion 110 is formed distal to the closed end. Note that a distal end opening 101 ( FIG. 6 ) is formed in the protruding portion proximal to the distal end portion 110 after the first core metal C1 is removed, but the formation of the distal end opening 101 may be omitted.

[0072] 8(D) shows the placement of the first cylindrical member 410a in the first layer forming process. As shown in FIG. 8(D), the operator covers the distal end portion 110 of the distal tube 11a (first tube) and the RX tube 30a (second tube) with the first cylindrical member 410a. In the illustrated example, the first cylindrical member 410a covers the entire portion from the distal end P3 of the RX tube 30a to the proximal end P4 of the distal end portion 110 of the distal tube 11a.

[0073] 8(E) illustrates the placement of the second heat-shrinkable tube ST2 during the first layer formation process. As shown in FIG. 8(E), the worker covers the first cylindrical member 410a with the second heat-shrinkable tube ST2. In the illustrated example, the second heat-shrinkable tube ST2 covers the entire first cylindrical member 410a, from the tip to the base end of the first cylindrical member 410a. The worker then heats at least a certain area of ​​the first cylindrical member 410a at a second temperature. The second temperature is set to a temperature at which the second heat-shrinkable tube ST2 thermally shrinks and the first cylindrical member 410a melts.

[0074] FIG. 8(F) shows the state after heating during the first layer formation process. After heating, the worker removes the second heat-shrinkable tube ST2. As shown in FIG. 8(F), the first cylindrical member 410a melts and is crushed as the second heat-shrinkable tube ST2 thermally shrinks, forming a first layer 410 extending along the distal end portion 110 and the distal end portion of the RX tube 30a. In the side view shown in FIG. 8(F), the outer edge of the first layer 410 on the side where the distal end portion 110 is located is inclined relative to the outer edge on the opposite side (in other words, the 360-degree symmetric cross section described in FIG. 7(A)), thereby securing the distal end portion 110 of the distal tube 11a (first tube) and the RX tube 30a (second tube).

[0075] 9A illustrates the placement of the second cylindrical member 420a during the second layer formation process. As illustrated in FIG. 9A, the worker covers the first layer 410 formed by the first cylindrical member 410a with the second cylindrical member 420a. In the illustrated example, the second cylindrical member 420a entirely covers the first layer 410 (first cylindrical member 410a) with its distal end positioned distal to the distal end of the first layer 410 (first cylindrical member 410a) and its proximal end positioned at the same position as the proximal end of the first layer 410 (first cylindrical member 410a).

[0076] 9B illustrates the placement of the third heat-shrinkable tube ST3 during the second layer formation process. As shown in FIG. 9B, the worker covers the second cylindrical member 420a with the third heat-shrinkable tube ST3. In the illustrated example, the third heat-shrinkable tube ST3 covers the entire second cylindrical member 420a, from the tip to the base end of the second cylindrical member 420a. The worker then heats at least a certain area of ​​the second cylindrical member 420a at a third temperature. The third temperature is set to a temperature at which the third heat-shrinkable tube ST3 thermally shrinks and the second cylindrical member 420a melts.

[0077] FIG. 9C illustrates the distal tip formation process. After heating, the worker removes the third heat-shrinkable tube ST3. As shown in FIG. 9C, the second cylindrical member 420a melts and is welded to the first layer 410 (first cylindrical member 410a) as the third heat-shrinkable tube ST3 thermally shrinks, forming a second layer 420 extending along the first layer 410 (first cylindrical member 410a). In the side view shown in FIG. 9C, the outer edge of the second layer 420 on the side where the distal end 110 is located is inclined relative to the outer edge on the opposite side (in other words, the 360-degree symmetric cross section described in FIG. 7A), thereby securing the first layer 410 (first cylindrical member 410a). The worker then cuts the distal end of the second layer 420 formed by the second cylindrical member 420a to the specified dimensions required for the distal tip 40 and then taperes it. The tapering process can be performed by, for example, heating the tip of the second layer 420 (second cylindrical member 420a) to form a rounded tapered shape at the tip, thereby forming a two-layered tip 40 consisting of the first layer 410 and the second layer 420, as described in FIG.

[0078] As described above, according to the catheter 1 of the first embodiment, as shown in Fig. 6, the distal end 1101 of the distal tube 11 (first tube) is located more distal than the proximal end 4202 of the distal tip and on the inner peripheral side of the distal tip 40, and the RX tube 30 (second tube) is in contact with the distal tip 40, so that both the distal tube 11 (first tube) and the RX tube 30 (second tube) can be fixed using the distal tip 40. As a result, the joining strength of the first and second tubes can be improved compared to when the first and second tubes are joined without using the distal tip 40.

[0079] 6, the first marker 41 is disposed in at least a portion of the longitudinal direction of the catheter 1 (medical device), from the distal end 1101 of the distal tube 11 (first tube) to the proximal end 4202 of the distal tip. Therefore, even if the distal tip 40 is not made of a radiopaque material, the position of the distal tip 40 can be grasped by the first marker 41. Furthermore, when the distal tip 40 is made of a radiopaque material as in the above embodiment, the radiopaque material has a multi-layer structure, which allows the image to appear darker in an X-ray image.

[0080] Furthermore, the catheter 1 of the first embodiment is provided with a radiopaque second marker 42 located closer to the proximal end than the first marker 41 and at a distance from the first marker 41. Therefore, the presence of two markers (the first marker 41 and the second marker 42) at positions spaced apart from each other in the longitudinal direction of the catheter 1 (medical device) improves the visibility of the catheter 1 under X-ray images. Furthermore, according to the catheter 1 of the first embodiment, the second marker 42 is located near the distal opening 201 of the OTW lumen 20L (third lumen), and therefore the position of the distal opening 201 of the third lumen can be ascertained by the second marker 42.

[0081] Furthermore, according to the catheter 1 of the first embodiment, the distal tip 40 has a first layer 410 and a second layer 420 covering the first layer 410, as shown in Fig. 6, which improves the visibility of the distal tip 40 under X-ray images in the overlapping portion between the first layer 410 and the second layer 420. Furthermore, as shown in the above embodiment (Fig. 6), when the first marker 41 is disposed in the section from the distal end 1101 of the distal tube 11 (first tube) to the proximal end 4202 of the distal tip, the visibility of the distal tip under X-ray images can be further improved in the overlapping portion between the first layer 410, the second layer 420, and the first marker 41.

[0082] Furthermore, according to the catheter 1 of the first embodiment, the distal tip 40 has a cross-sectional shape that is 360-degree symmetrical at the base end, as shown in Fig. 7 , which allows the catheter 1 (medical device) to be easily bent in the direction intended by the surgeon during a procedure using the catheter 1. Specifically, compared to a catheter 1 in which all components have a circular cross-section, the catheter 1 can be easily bent in the specific direction indicated by the arrow DZ in Fig. 7 . Furthermore, according to the catheter 1 of the first embodiment, the outer periphery of the distal tip 40 has a generally elliptical shape, as shown in Fig. 7 , in which the major axis AL intersects with the distal tube 11 (first tube) and the minor axis AS does not intersect with the distal tube 11 (first tube). This allows the catheter 1 (medical device) to be easily bent in the minor axis direction DZ of the outer periphery of the distal tip 40.

[0083] Furthermore, according to the catheter 1 of the first embodiment, the length L41 of the first marker 41 is longer than the length L42 of the second marker 42, so that the image of the first marker 41 can be made longer than the image of the second marker 42 on an X-ray image. As a result, the surgeon can easily distinguish between the first marker 41 and the second marker 42.

[0084] Furthermore, according to the manufacturing method of the catheter 1 of the first embodiment, the arrangement step shown in Fig. 8(A) makes it possible to form the distal end portion 110 having a shape suitable for fixation using the distal tip 40 (specifically, the first cylindrical member 410a and the second cylindrical member 420a) on the distal end side of the distal end tube 11a (first tube). Also, in the arrangement step shown in Fig. 8(A), the length of the distal end portion 110 can be controlled by adjusting the distal end position P1 of the first core bar C1 and the distal end position P2 of the distal end tube 11a (first tube).

[0085] Furthermore, according to the manufacturing method of the catheter 1 of the first embodiment, in the first layer forming step shown in Figures 8(D) to 8(F), the distal end portion 110 of the distal end tube 11a (first tube) and the RX tube 30a (second tube) are sandwiched and fixed using the second core bar C2 and the first cylindrical member 410a, so that the distal end tube 11a and the RX tube 30a can be firmly fixed together. Also, the second layer forming step shown in Figures 9(A) and 9(B) can form a distal tip 40 with a two-layer structure.

[0086] Second Embodiment Fig. 10 is an enlarged view of the distal end of a catheter 1A according to a second embodiment. The catheter 1A of the second embodiment has the same configuration as that described in the first embodiment, but includes a first marker 41A instead of the first marker 41. The lower part of Fig. 10 shows transverse cross-sectional views of the first marker 41A and the second marker 42 in speech bubbles.

[0087] The first marker 41A differs from the first embodiment in length L41A and thickness T41A. Specifically, the length L41A of the first marker 41A in the longitudinal direction of the catheter 1A is the same as the length L42 of the second marker 42. That is, length L40 > L41A = L42. Also, as shown in the balloon, the thickness T41A of the first marker 41 is thicker than the thickness T42 of the second marker 42 (thickness T41A > T42).

[0088] As described above, various modifications are possible to the configurations of the first marker 41A and the second marker 42. In the example of Fig. 10, the first marker 41A has the same length L41A and a larger thickness T41A than the second marker 42. However, the first marker 41A may have a longer length L41A and a larger thickness T41A than the second marker 42 (L41A > L42, T41A > T42). Alternatively, the first marker 41A may have the same length L41A and the same thickness T41A as the second marker 42 (L41A = L42, T41A = T42). In this case, when manufacturing the first marker 41A and the second marker 42, the visibility of the first marker 41A in an X-ray image may be made higher than that of the second marker 42 by changing the type and mixing ratio of the radiopaque material mixed into the resin material.

[0089] The catheter 1A of the second embodiment as described above can also achieve the same effects as those of the first embodiment. Furthermore, according to the catheter 1A (medical device) of the second embodiment, the thickness T41A of the first marker 41A is greater than the thickness T42 of the second marker 42, so that the image of the first marker 41A can be made darker than the image of the second marker 42 on an X-ray image. As a result, the surgeon can easily distinguish between the first marker 41A and the second marker 42.

[0090] 11 is an enlarged view of the distal end of a catheter 1B according to a third embodiment. The catheter 1B of the third embodiment has the same configuration as that described in the first embodiment, except that it includes a first marker 41B instead of the first marker 41 and a second marker 42B instead of the second marker 42.

[0091] The first marker 41B is positioned so as not to overlap with the distal tip 40. In the illustrated example, the first marker 41B is positioned so that the distal end of the first marker 41B is adjacent to the proximal end 4202 of the distal tip 40. In other words, the distal surface of the first marker 41B is in contact with the proximal end surface of the distal tip 40. The second marker 42B is positioned so that the center of the second marker 42B is located in the longitudinal direction of the catheter 1B at the center of the distal opening 201 (distal opening) of the OTW lumen 20L (third lumen).

[0092] As described above, various modifications are possible to the configurations of the first marker 41B and the second marker 42B. The first marker 41B may be in contact with the distal tip 40 but may not overlap with the distal tip 40, and the second marker 42B may be positioned at any position near the distal opening 201. The catheter 1B of the third embodiment as described above can also achieve the same effects as the first embodiment.

[0093] Fourth Embodiment Fig. 12 is an enlarged view of the distal end side of a catheter 1C of a fourth embodiment. The catheter 1C of the fourth embodiment includes a first marker 41C instead of the first marker 41 and a second marker 42C instead of the second marker 42 in the configuration described in the first embodiment. The first marker 41C does not overlap the distal tip 40 and is positioned away from the distal tip 40. The second marker 42C is positioned near the distal opening 201 of the OTW lumen 20L (third lumen) and closer to the proximal end than the distal opening 201. As described above, the configurations of the first marker 41C and the second marker 42C can be modified in various ways. The first marker 41C does not need to contact or overlap the distal tip 40, and the second marker 42C may be positioned at any position near the distal opening 201. The catheter 1C of the fourth embodiment described above can also achieve the same effects as the first embodiment described above.

[0094] <Fifth embodiment> Figure 13 is a cross-sectional view of a catheter 1D of a fifth embodiment. Figure 13 shows the cross-section of the catheter 1D taken along line F-F in Figure 6, in other words, the cross-section of the catheter 1D at the proximal end of the distal tip 40D. The catheter 1D of the fifth embodiment has the configuration described in the first embodiment, but includes a distal tip 40D instead of the distal tip 40.

[0095] The distal tip 40D is composed of a single layer. In the cross section shown in Figure 13, the contour of the outer periphery of the distal tip 40D is a perfect circle. Therefore, the axis ASD = ALD passing through the center O of the circle. The contour of the outer periphery of the distal tip 40D in the cross section of Figure 13 is not symmetrical across 360 degrees. On the other hand, the configuration of each component of the catheter 1D in the cross section of Figure 13 is symmetrical across 360 degrees. This is due to the presence of the distal end portion 110.

[0096] As described above, the configuration of the distal tip 40D can be modified in various ways, and it may be formed from a single layer. In this case, the second layer formation step described in FIG. 9 can be omitted. The distal tip 40D may also have a layer configuration of three or more layers. In this case, after the second layer formation step described in FIG. 9, a third layer can be layered on the second layer 420 using a third cylindrical member. The distal tip 40D may also have a cross-sectional shape other than an ellipse. While a perfect circle is illustrated in FIG. 13, this is not limiting. The catheter 1D of the fifth embodiment described above can also achieve the same effects as the first embodiment described above.

[0097] <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.

[0098] [Modification 1] In the above first to fifth embodiments, one example of the configuration of the catheters 1, 1A to 1D is shown. However, the configuration of the catheters 1, 1A to 1D can be modified in various ways.

[0099] For example, at least one of the sensor tube 10 and the OTW tube 20 may be configured with a single tube body (tubular body) from the distal end to the proximal end, without having the distal tube 11, 21 and the proximal tube 12, 22. Furthermore, at least one of the tubes 10, 20, 30 may be configured with three or more tube bodies (tubular bodies) arranged along the longitudinal direction of the catheter 1.

[0100] For example, the outer circumferential surfaces of the first outer tube 50, the heat-shrinkable tube 90, and the second outer tube 80, or the outer circumferential 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. However, the sensor 70 may also be configured to be removable from the catheter 1. In other words, the catheter 1 does not have to include the sensor 70 as a component.

[0101] For example, at least one of the first marker 41 and the second marker 42 may be omitted. For example, the shapes of the first marker 41 and the second marker 42 can be changed as desired. 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 linear shape, or a coil shape formed by spirally winding a wire). For example, the first marker 41 and the second marker 42 may be disposed on a tube (such as the sensor tube 10 or the OTW tube 20) other than the RX tube 30. The first marker 41 and the second marker 42 may be disposed on the same tube as described above, or may be disposed on different tubes.

[0102] For example, at least one of the first outer tube 50, the second outer tube 80, and the heat-shrinkable tube 90 may be omitted. For example, in the above embodiment, the tubes 50, 80, and 90 each consist of a single layer, but at least one of the tubes 50, 80, and 90 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, and 30).

[0103] 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.

[0104] For example, the manufacturing method of the catheters 1, 1A to 1D described in Figures 8 and 9 is merely an example, and various modifications are possible. For example, additional steps may be added between the above-described steps, such as pre-processing for processing or for arranging other components not described.

[0105] [Modification 2] The configurations of the catheters 1, 1A to 1D of the first to fifth embodiments and the configuration of the catheters 1, 1A to 1D of Modification 1 may be combined as appropriate. For example, the first and second markers 41, 42 described in any of the second to fourth embodiments may be combined with the distal tip 40D described in the fifth embodiment.

[0106] 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, Tip and A first tube having a first lumen, wherein the tip of the first tube is located on the tip side of the base end of the tip tip and on the inner circumference side of the tip tip, A second tube having a second lumen and in contact with the tip, A medical device equipped with the following features.

2. A medical device according to claim 1, further, The second tube is provided with a marker that is radiopaque, The marker is positioned in at least a portion of the longitudinal direction of the medical device, from the tip of the first tube to the base of the tip, in a medical device.

3. A medical device according to claim 2, further, The aforementioned marker is the first marker, A medical device comprising a second marker which is radiopaque, located proximal to the first marker and at a distance from the first marker.

4. A medical device according to claim 3, further, A medical device comprising a third tube having a third lumen, the tip of which communicates with the outside, and the tip opening located near the second marker.

5. A medical device according to any one of claims 1 to 4, The tip comprises a first layer and a second layer covering the first layer. The tip of the first layer is located closer to the base than the tip of the second layer. A medical device in which both the first layer and the second layer are radiopaque.

6. A medical device according to any one of claims 1 to 4, A medical device in which the cross-sectional shape at the base end of the aforementioned tip is 360-degree symmetrical.

7. A medical device according to claim 6, A medical device in which, in the cross-section, the outer circumference of the tip is substantially elliptical in shape, with its major axis intersecting the first tube and its minor axis not intersecting the first tube.

8. A method for manufacturing a medical device, A first tube into which a first core metal is inserted and a second tube into which a second core metal is inserted are arranged such that the tip of the first core metal is located closer to the base end than the tip of the first tube, and the tip of the first tube is located closer to the base end than the tip of the second tube. The tip of the first tube is covered with a heat-shrinkable tube from the tip of the first core metal, and the heat shrinkage of the heat-shrinkable tube is used to form a tip portion on the tip side of the first tube in which the lumen inside the first tube is closed and which extends along the outer surface of the second tube beyond the closed end. A method for manufacturing medical devices, including the following.

9. A method for manufacturing a medical device according to claim 8, The heat shrink tube is a first heat shrink tube, After the tip portion is formed, the tip portion and the second tube are covered with a cylindrical member made of resin. The cylindrical member is covered with a second heat shrink tube. A method for manufacturing a medical device, comprising using the thermal shrinkage of the second heat-shrinkable tube to fix the cylindrical member to the tip of the first tube and the second tube.

10. A method for manufacturing a medical device according to claim 9, The cylindrical member is the first cylindrical member, The first cylindrical member is covered with a second cylindrical member made of resin. The second cylindrical member is fixed to the first cylindrical member by welding the second cylindrical member, A method for manufacturing a medical device, comprising forming a tip by tapering the tip end of the second cylindrical member.