Medical device

Abstract

A medical device according to the present invention comprises: a first tube that includes a first lumen; a second tube that is disposed alongside the first tube and includes a second lumen, the second tube being formed to have, at the distal end thereof, a first distal end opening that connects the second lumen and the outside; a third tube that is disposed alongside the first and second tubes and includes a third lumen; and a film that couples a portion of the first tube that is located further to the distal end side than the first distal end opening and a portion of the third tube that is located further to the distal end side than the first distal end opening.

Description

medical devices

[0001] The present disclosure relates to medical devices.

[0002] Medical devices for acquiring ultrasound images are known. For example, Patent Documents 1 and 2 describe catheters with an ultrasound transducer at their tip that transmits and receives ultrasound waves toward biological tissue. Hereinafter, an ultrasound image acquisition mechanism including an ultrasound transducer will also be referred to as a "sensor." Using such medical devices to perform percutaneous procedures can improve the safety and efficiency of the procedures.

[0003] JP 2001-245886 A JP 2006-20944 A

[0004] In the above-mentioned medical devices, multiple lumens are provided in the device by combining multiple tubes or using a multi-lumen tube. In medical devices with multiple lumens, depending on the circumferential orientation of the medical device within a blood vessel, the outlet of the treatment device may not be in the direction of the target treatment site, making the procedure difficult. Under such circumstances, it is not always easy to rotate the medical device within the blood vessel to change the circumferential orientation of the medical device within the blood vessel. In particular, when the medical device is located within a false lumen, rotating the medical device within the blood vessel carries the risk of expanding the false lumen. The technologies described in Patent Documents 1 and 2 do not take such issues into consideration at all.

[0005] These problems are not limited to medical devices with built-in sensors, but are also common to medical devices into which sensors can be inserted and used in combination with sensors, and are not limited to the vascular system, but are also 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 disclosure has been made to solve at least some of the above-mentioned problems, and aims to make it easier to direct a therapeutic device within a lumen in the direction of the target treatment site in a medical device having multiple lumens.

[0007] The present disclosure 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 disclosure, there is provided a medical device comprising: a first tube having a first lumen; a second tube arranged alongside the first tube and having a second lumen, the second tube having a first distal opening at a distal end of the second tube that connects the second lumen to the outside; a third tube arranged alongside the first and second tubes and having a third lumen; and a membrane connecting a portion of the first tube located distal to the first distal opening and a portion of the third tube located distal to the first distal opening.

[0009] According to this configuration, the first tube and the third tube are connected by a membrane distal to the first distal opening of the second tube. Therefore, when an operator inserts a treatment device into the second lumen and projects the distal end of the treatment device from the first distal opening, even if the target site of treatment is located between the first and third tubes, the operator can pass the distal end of the treatment device between the first and third tubes by piercing the membrane with the distal end of the treatment device, thereby reaching the target site. As a result, a medical device can be provided that makes it easy to direct the treatment device in the lumen toward the target site of treatment.

[0010] (2) In the medical device of the above embodiment, the membrane may swell in a wet state when wetted with a liquid, thereby improving flexibility compared to a non-wet state. According to this configuration, when a surgeon inserts the medical device into a blood vessel and the membrane becomes wetted with blood, the membrane swells and becomes more flexible compared to a non-wet state. Therefore, the surgeon can easily break through the membrane with the tip of a treatment device during a procedure using the medical device.

[0011] (3) In the medical device of the above aspect, a first proximal end opening may be formed at the proximal end of the second tube, connecting the second lumen to the outside, and a side opening may be formed on a side surface of the second tube between the first distal end opening and the first proximal end opening, connecting the second lumen to the outside. With this configuration, since a side opening is formed between the first distal end opening and the first proximal end opening of the second tube, the surgeon can protrude the distal end of the treatment device from the side opening instead of the first distal end opening. As a result, the usability of the medical device can be further improved.

[0012] (4) In the medical device of the above aspect, a second distal opening connecting the third lumen to the outside may be formed at the distal end of the third tube, a second proximal opening connecting the third lumen to the outside may be formed at the proximal end of the third tube, a third opening connecting the third lumen to the outside and a fourth opening connecting the third lumen to the outside may be formed between the second distal opening and the second proximal opening, the third opening may be provided distally of the side opening of the second tube, and the fourth opening may be provided proximally of the side opening of the second tube, and a gap may exist between the third opening and the fourth opening in the third tube. According to this configuration, a gap exists in the third tube between the third opening provided distally of the side opening of the second tube and the fourth opening provided proximally of the side opening of the second tube. That is, because there is a gap in the third tube at the position of the side opening of the second tube, when the surgeon pushes the distal end of the treatment device out of the side opening, the distal end of the treatment device is prevented from interfering with the third tube, making it easier to direct the treatment device in the lumen toward the target site of treatment.

[0013] (5) In the medical device of the above aspect, the side opening of the second tube may be located on the gap side in the circumferential direction of the second tube. With this configuration, the side opening of the second tube is located on the gap side in the circumferential direction of the second tube. This further reduces interference between the distal end of the treatment device and the third tube when the surgeon extends the distal end of the treatment device through the side opening. As a result, the treatment device in the lumen can be more easily directed toward the target treatment site.

[0014] (6) In the medical device of the above aspect, the third tube may include a distal third tube disposed on the distal side and a proximal third tube disposed on the proximal side of the distal third tube and away from the distal third tube, the second distal opening and the third opening may be provided in the distal third tube, and the fourth opening and the second proximal opening may be provided in the proximal third tube. With this configuration, the third tube having a gap between the third opening and the fourth opening can be formed by two tubes.

[0015] (7) In the medical device of the above aspect, a notch may be provided on a side surface of the third tube between the second distal opening and the second proximal opening by cutting away a thick portion of the third tube over a predetermined range in the circumferential and longitudinal directions, the third opening being the distal end of the notch, and the fourth opening being the proximal end of the notch. With this configuration, the third tube having a gap between the third opening and the fourth opening can be formed from a single tube.

[0016] (8) In the medical device of the above aspect, the first tube may be made of a first material, the third tube may be made of a second material, and the first material and the second material may have different acoustic impedances. With this configuration, the first material and the second material have different acoustic impedances, making it easy to distinguish the first tube from the third tube in an image acquired by a sensor.

[0017] (9) In the medical device of the above aspect, the second tube may be formed of a third material, and the first material and the third material may have different acoustic impedances. With this configuration, the first material and the third material have different acoustic impedances, making it easy to distinguish the first tube from the second tube in an image acquired by a sensor.

[0018] (10) In the medical device of the above aspect, the second material and the third material may have different acoustic impedances. With this configuration, the second material and the third material have different acoustic impedances, making it easy to distinguish the third tube from the second tube in an image acquired by the sensor.

[0019] The present disclosure 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 the same.

[0020] 12. An explanatory diagram illustrating the configuration of a medical device. An explanatory diagram illustrating the configuration of a medical device. A diagram showing a cross section of a catheter. A diagram showing a cross section of a catheter. A diagram showing a cross section of a catheter. A diagram showing a cross section of a catheter. A diagram showing a cross section of a catheter. A diagram explaining a method of using a catheter. A diagram explaining a method of using a catheter. An enlarged view of the distal end side of a catheter. A cross sectional view of the catheter taken along line F-F in FIG. 10. A diagram explaining an approach using a distal end opening of the catheter. A diagram showing the catheter as seen from direction A in FIG. 12. A diagram explaining an approach using a side opening of the catheter. A cross sectional view of the catheter and blood vessel taken along line G-G in FIG. 14. A cross sectional view of a catheter of a second embodiment. A cross sectional view of a catheter of a third embodiment. An explanatory diagram illustrating the configuration of a catheter of a fourth embodiment. An explanatory view of an RX tube of a fifth embodiment. An enlarged view of the distal end side of a catheter of a sixth embodiment. An enlarged view of the distal end side of a catheter of a seventh embodiment.

[0021] First Embodiment FIGS. 1 and 2 are explanatory diagrams illustrating 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 occurring in a blood vessel. Hereinafter, the medical device 1 will also be referred to as a "catheter 1." CTO stands for Chronic Total Occlusion. As shown in FIGS. 1 and 2, the catheter 1 includes a sensor tube 10, an OTW tube 20, an RX tube 30, a first marker 41, a second marker 42, a first outer tube 50, a branch connector 60, first to third reinforcing members 61 to 63, an outer tubular member 64, an inner tubular member 67, a connector 65, a connector 25, a sensor 70, a second outer tube 80, and a heat-shrinkable tube 90. OTW stands for Over-The-Wire. RX stands for Rapid Exchange.

[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 differ from the actual ratios. Some of the components are exaggerated. 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 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 manipulated by an operator such as a physician. These points are also common to Figures 3 and subsequent figures. In this embodiment, "same" and "equal" do not necessarily mean exact agreement, but rather mean allowing for differences due to manufacturing errors, etc. "Constant" is synonymous with "generally constant," meaning roughly constant while allowing for variations due to manufacturing errors, etc.

[0024] Figures 3 to 7 are diagrams showing cross sections of the catheter 1. Figure 3 is a cross section of the catheter 1 taken along line A-A in Figure 1. Figure 4 is a cross section of the catheter 1 taken along line B-B in Figure 1. Figure 5 is a cross section of the catheter 1 taken along line CC in Figure 1. Figure 6 is a cross section of the catheter 1 taken along line D-D in Figure 1. Figure 7 is a cross section of the catheter 1 taken along line E-E in Figure 1. The configuration of the catheter 1 will be described below with reference to Figures 1 to 7.

[0025] The sensor tube 10 is a cylindrical member having a long outer shape. The sensor tube 10 is a tubular body. The sensor tube 10 extends linearly along the longitudinal direction of the catheter 1, parallel to the OTW tube 20 and the RX tube 30. A sensor lumen 10L for accommodating the sensor 70 is formed inside the sensor tube 10. The sensor lumen 10L is shown by a dashed line in FIG. 1 . 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 of the OTW lumen 20L and the proximal end of the RX tube 30 in the longitudinal direction of the catheter 1. The proximal end of the sensor tube 10 is inserted into the lumen of the inner tubular member 67 and is held in a state where it can move relative to the inner tubular member 67. In other words, the inner tubular member 67 is arranged along the outer peripheral surface of the proximal end of the sensor tube 10 in a state where it can move in the longitudinal direction of the sensor tube 10. The lumen of the inner tubular member 67 is connected to the sensor lumen 10L. The proximal end of the inner cylindrical member 67 is fixed to a connector 65. A fluid supply unit 66 is attached to the connector 65, and a proximal end opening 102 is formed in the fluid supply unit 66, connecting the inner cavity of the inner cylindrical member 67 and the proximal end of the sensor lumen 10L with the outside. The proximal end opening 102 is a fluid supply port for the inner cavity of the inner cylindrical member 67 and the sensor lumen 10L.

[0027] As shown in FIG. 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 having elongated outer shapes. The distal tube 11 and the proximal tube 12 are both tubular bodies. 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 sensor lumen 10L includes the inner lumen of the distal tube 11 and the inner lumen of the proximal tube 12.

[0028] The OTW tube 20 is a cylindrical member having a long outer shape. The OTW tube 20 is a tubular body. 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 for accommodating a therapeutic device is formed inside the OTW tube 20. In FIG. 1 , the OTW lumen 20L is indicated by a dashed line. The OTW lumen 20L is a so-called over-the-wire type lumen that does not have an opening in the portion that is placed in the biological lumen when the catheter 1 is in use. Examples of the therapeutic device include a plasma guidewire and a penetration guidewire.

[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 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 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. The distal opening 201 has an elliptical shape in which the distal end of the OTW tube 20 is cut obliquely. "Oblique" refers to a direction that intersects the longitudinal direction of the catheter 1 and that moves toward the center of the catheter 1 as it moves from the proximal end to the distal end. 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. 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 to the proximal end side of the OTW tube 20, 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. A side opening 203 is formed on the side surface of the OTW tube 20. The side opening 203 is provided between the distal opening 201 and the proximal end opening 202. The side opening 203 is a hole provided in a portion of the side wall of the OTW tube 20, and connects the OTW lumen 20L to the outside.

[0030] As shown in FIG. 1 , the OTW tube 20 includes a distal tube 21 disposed on the distal side and a proximal tube 22 disposed proximal to the distal tube 21. The distal tube 21 and the proximal tube 22 are both cylindrical members having an elongated outer shape. The distal tube 21 and the proximal tube 22 are both tubular bodies. 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 OTW lumen 20L includes the lumen of the distal tube 21 and the lumen of the proximal tube 22. The side opening 203 described above is provided in the distal tube 21 of the OTW tube 20.

[0031] The RX tube 30 is a cylindrical member having an elongated outer shape. The RX tube 30 is a tubular body. 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 for accommodating a work hose wire is formed inside the RX tube 30. The RX lumen 30L is indicated by a dashed line in FIG. 1 . A hollow distal tip 40 is joined to the distal end of the RX tube 30. Details of the distal tip 40 will be described later. That is, the RX tube 30 includes the distal tip 40. The RX lumen 30L includes the lumen of the RX tube 30 and the lumen of the distal tip 40. The distal end of the RX lumen 30L is located distal to the distal end of the sensor lumen 10L.

[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 distal opening 301 is formed at the distal end of the RX tube 30, connecting the distal end of the RX lumen 30L to the outside. Specifically, the distal opening 301 is formed at the distal end of the distal tip 40. 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 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 opening 302 is a wire withdrawal port for withdrawing the work horse wire to the outside. The proximal end opening 302 has an elliptical shape formed by cutting the proximal end of the RX tube 30 obliquely, and 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 proximal end opening 302 when the catheter 1 is in use.

[0033] As shown in FIG. 1 , the RX tube 30 includes a distal tube 31 disposed on the distal side and a proximal tube 32 disposed proximal to the distal tube 31. The distal tube 31 and the proximal tube 32 are both cylindrical members having elongated outer shapes. The distal tube 31 and the proximal tube 32 are both tubular bodies. As shown in FIG. 1 , the proximal tube 32 is disposed at a position longitudinally spaced from the proximal end of the distal tube 31 toward the proximal side. Therefore, there is a portion between the distal tube 31 and the proximal tube 32 where the RX tube 30 does not exist. The portion where the RX tube 30 does not exist is also referred to as a gap 33. Of the above-mentioned RX lumens 30L, the lumen of the distal tube 31 is referred to as a first RX lumen 30L, and the lumen of the proximal tube 32 is also referred to as a second RX lumen 30L. The RX lumen 30L includes a first RX lumen 30L and a second RX lumen 30L.

[0034] A third opening 303 is formed at the proximal end of the distal tube 31, connecting the proximal end of the first RX lumen 30L to the outside. The third opening 303 is located between the distal opening 301 and the proximal opening 302 in the longitudinal direction of the catheter 1, and is located further distally than the fourth opening 304. The third opening 303 has an elliptical shape with the proximal end of the distal tube 31 cut obliquely, and faces in a direction intersecting the longitudinal direction of the catheter 1. The distal opening 301 and the third opening 303 are located in the distal tube 31 of the RX tube 30. A fourth opening 304 is formed at the distal end of the proximal tube 32, connecting the distal end of the second RX lumen 30L to the outside. The fourth opening 304 is located between the distal opening 301 and the proximal opening 302 in the longitudinal direction of the catheter 1, and is located further proximally than the third opening 303. The fourth opening 304 has an elliptical shape formed by cutting the tip of the proximal tube 32 obliquely, and faces in a direction intersecting the longitudinal direction of the catheter 1. The proximal opening 302 and the fourth opening 304 are provided in the proximal tube 32 of the RX tube 30.

[0035] 1 , the third opening 303 of the RX tube 30 is provided at a position further distally than the side opening 203 of the OTW tube 20. The fourth opening 304 of the RX tube 30 is provided at a position further proximally than the side opening 203 of the OTW tube 20. Between the third opening 303 and the fourth opening 304 is a gap 33 where the RX tube 30 is not present. That is, in the catheter 1, the position of the side opening 203 and the peripheral position of the side opening 203 coincide with the position of the gap 33 of the RX tube 30. In the catheter 1, the position of the side opening 203 and the peripheral position of the side opening 203 are gap 33 where the RX tube 30 is not present.

[0036] The distal opening 201 of the OTW tube 20 is inclined in a direction that exposes the inside of the OTW lumen 20L more widely to the outside when viewed from the outer circumferential surface side of the catheter 1. Similarly, the proximal opening 302, third opening 303, and fourth opening 304 of the RX tube 30 are all inclined in a direction that exposes the inside of the RX lumen 30L more widely to the outside when viewed from the outer circumferential surface side of the catheter 1. The distal opening 201 and the fourth opening 304 are inclined in a direction that the wall thickness of the tube gradually decreases from the proximal end to the distal end. The proximal opening 302 and the third opening 303 are inclined in a direction that the wall thickness of the tube gradually increases from the proximal end to the distal end.

[0037] 1 , at the location of the distal opening 201 of the OTW tube 20, there are three tubes: the obliquely cut distal tube 21, the obliquely cut distal tube 31, and the distal tube 11. At this location, the distal tube 21, the distal tube 31, and the distal tube 11 may be spot welded together by laser to facilitate fine processing.

[0038] 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 end of the RX tube 30, and advances through the biological lumen ahead of other members. The lumen of the distal tip 40 is connected to 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, connecting the distal end of the RX lumen 30L to the outside.

[0039] 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 center of the second marker 42 and the distal tip of the distal 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 arranging the first marker 41 and the second marker 42 on the RX tube 30 instead of the sensor tube 10, it is possible to prevent the first marker 41 and the second marker 42 from interfering with sensing by the sensor 70. Sensing means the acquisition of image information by the sensor 70.

[0040] 3, in the cross section taken along line A-A, the distal tube 11 of the sensor tube 10 and the distal tube 31 of the RX tube 30 are arranged. In the A-A cross section, the sensor tube 10 and the RX tube 30 are joined together with a portion of the outer circumferential surface of the sensor tube 10 and a portion of the outer circumferential surface of the RX tube 30 in contact with each other. Details will be described later.

[0041] As shown in FIG. 4 , the distal tube 11 of the sensor tube 10 and the distal tube 21 of the OTW tube 20 are disposed in the cross section taken along line B-B. Because the B-B cross section corresponds to the gap 33 between the distal tube 31 and the proximal tube 32, the RX tube 30 is not present in the B-B cross section. In the B-B cross section, the sensor tube 10 and the OTW tube 20 are joined together with a portion of the outer circumferential surface of the sensor tube 10 and a portion of the outer circumferential surface of the OTW tube 20 in contact with each other. The sensor tube 10 and the OTW tube 20 may be joined together in this region using any bonding agent, such as an epoxy adhesive, or may be thermally welded. As shown in FIG. 4 , the side opening 203 of the OTW tube 20 is located on the gap 33 side in the circumferential direction of the OTW tube 20.

[0042] As shown in FIG. 5 , in the cross section taken along line CC, the distal tube 11 of the sensor tube 10, the distal tube 21 of the OTW tube 20, and the proximal tube 32 of 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 FIG. 6 , in the cross section taken along line DD, the distal tube 11 of the sensor tube 10, the proximal tube 22 of the OTW tube 20, and the proximal tube 32 of the RX tube 30 are covered by the first outer tube 50, as in FIG. 5 . As shown in FIG. 7 , in the cross section taken along line EE, the proximal tube 12 of the sensor tube 10 and the proximal tube 22 of the OTW tube 20 are covered by the second outer tube 80. Specifically, the outer circumferential surfaces of the two tubes 10, 20 are covered with a melt-molded second outer tube 80, thereby fixing the two tubes 10, 20 together.

[0043] In the A-A 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. In the B-B cross section and the E-E cross section, the height LY of the catheter 1 is less than the width LZ of the catheter 1. As shown in FIGS. 3 to 7 , the relationship in size 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. The relationship in size between the inner diameters 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 in size between the outer diameters and inner diameters are merely examples and may be changed as desired.

[0044] The outer shape of the catheter 1 in the A-A cross section and the B-B cross section is a shape that follows the outline of the adjacent tubes, and a constriction is formed in the adjacent portion of each tube. The constriction is also called a recess. The outer shape of the catheter 1 in the C-C cross section and the D-D cross section, in other words, the portion covered by the first outer tube 50, is a triangle with rounded corners. A triangle with rounded corners is also called a round-corner triangle. The outer shape of the catheter 1 in the E-E cross section, in other words, the portion covered by the second outer tube 80, is an ellipse.

[0045] 1, the sensor tube 10, the OTW tube 20, and the RX tube 30 are fixed by three tubes 90, 50, and 80.

[0046] The heat shrink 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 shrink tube 90 covers a portion of the distal end side of the proximal tube 12 of the sensor tube 10 and a portion of the distal end side of the proximal tube 22 of the OTW tube 20, bundling them together. The heat shrink tube 90 does not cover the RX tube 30. The proximal tube 32 of the RX tube 30 is disposed along the outer circumferential surface of the heat shrink tube 90, with the outer circumferential surface of the heat shrink tube 90 in contact with the outer circumferential surface of the proximal tube 32 of the RX tube 30. The distal end of the heat shrink 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. In other words, the distal end portion of the heat shrink 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. In other words, the base end of the heat-shrinkable tube 90 is covered by the second outer tube 80. An 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.

[0047] 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 by the sensor 70 inserted in the sensor lumen 10L. The first outer tube 50 covers and fixes the tip end of the heat shrink tube 90, a portion of the sensor tube 10 exposed from the tip end of the heat shrink tube 90, a portion of the OTW tube 20 exposed from the tip end of the heat shrink tube 90, and a portion of the base end side of the RX tube 30. As shown in Figures 5 and 6, the first outer tube 50 has an outer shape of a triangle with rounded corners, and has thick-walled portions that are melt-molded along the outer peripheral surfaces of the three tubes 10, 20, and 30.

[0048] The second outer tube 80 is disposed closer to the proximal end than the heat-shrinkable 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 shown in 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 secures the proximal end of the heat-shrinkable tube 90, a portion of the sensor tube 10 exposed from the proximal end of the heat-shrinkable tube 90, and a portion of the OTW tube 20 exposed from the proximal end of the heat-shrinkable tube 90. As shown in FIG. 7 , the second outer tube 80 has an elliptical outer shape and a thick-walled portion melt-formed along the outer circumferential surfaces of the two tubes 10, 20.

[0049] The proximal end of the catheter 1 is provided with a first reinforcing member 61 and a branch connector 60, arranged from the distal end toward the proximal end. The first reinforcing member 61 is a cylindrical member located distally of the branch connector 60. The first reinforcing member 61 reinforces the distal end of the branch connector 60 by covering the outer periphery of the second outer tube 80, which bundles the sensor tube 10 and the OTW tube 20. The branch connector 60 is attached proximally of the first reinforcing member 61. The branch connector 60 is a member having a bifurcated lumen. 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.

[0050] On one side of the branch connector 60, a second reinforcing member 62, a third reinforcing member 63, and a connector 25 are provided, from the distal end toward the proximal end. The second reinforcing member 62 is a cylindrical member located closer to the proximal end than the branch connector 60. The second reinforcing member 62 covers the outer periphery of the OTW tube 20 inserted into the branch connector 60, thereby reinforcing the proximal end of 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 covers the outer periphery of the OTW tube 20 inserted into the connector 25, thereby reinforcing the distal end of 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 is formed at the proximal end of the connector 25, connecting the proximal end of the OTW lumen 20L to the outside. The proximal opening 202 is an insertion port for a treatment device.

[0051] On the other side of the branch connector 60, an outer tubular member 64, an inner tubular member 67, and a connector 65 are provided, from the distal end to the proximal end. The outer tubular member 64 is a cylindrical member located closer to the proximal end than the branch connector 60. The inner tubular member 67 is passed through the inner cavity of the outer tubular member 64 and is held in a state where it can move relative to the outer tubular member 64. Protrusions are provided on the inner circumferential surface of the proximal end of the outer tubular member 64 and on the outer circumferential surface of the distal end of the inner tubular member 67. These protrusions engage with each other to prevent the inner tubular member 67 from detaching from the outer tubular member 64 during relative movement. The proximal end of the sensor tube 10 is inserted into the inner cavity of the outer tubular member 64. The sensor tube 10 is held in a state where it can move relative to the inner tubular member 67. In other words, the inner cylindrical member 67 is disposed along the outer peripheral surface of the proximal end of the sensor tube 10 in a state in which it can move in the longitudinal direction of the sensor tube 10. The connector 65 is a member joined to the proximal end of the inner cylindrical member 67. A housing for accommodating a connection terminal 75 of the sensor 70 is provided on the proximal end side of the connector 65. A fluid supply section 66 is provided on the outer peripheral surface of the connector 65. The fluid supply section 66 has a proximal end opening 102 that connects the proximal end of the sensor lumen 10L and the proximal end of the lumen of the inner cylindrical member 67 to the outside. The lumen of the inner cylindrical member 67 is part of the sensor lumen 10L.

[0052] The sensor 70 shown in 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 electrically connecting the probe 72 and the connection terminal 75 is built into the main body 71. The driving cable is a coaxial cable. The probe 72 includes an ultrasound probe that transmits ultrasound toward biological tissue and receives ultrasound reflected from the biological tissue. The ultrasound probe is also called an ultrasound vibrator, piezoelectric element, ultrasound transmitting / receiving element, or ultrasound element. 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 in the housing of the connector 65.

[0053] 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 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." A portion of the catheter 1 that is particularly suitable for sensing 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.

[0054] The distal tube 11 of the sensor tube 10, the distal tube 21 of the OTW tube 20, and the distal tube 31 and proximal tube 32 of the RX tube 30 can be formed from a flexible material. Examples of flexible materials include 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. In this embodiment, the distal tube 11 of the sensor tube 10 is formed from a first material. The distal tube 21 of the OTW tube 20 is formed from a third material. The distal tube 31 and proximal tube 32 of the RX tube 30 are formed from a second material. The first and second materials have different acoustic impedances. The first and third materials have different acoustic impedances. The second material and the third material have different acoustic impedances. However, the distal tube 11 of the sensor tube 10, the distal tube 21 of the OTW tube 20, the distal tube 31 of the RX tube 30, and the proximal tube 32 of the RX tube 30 may be made of the same material.

[0055] The proximal tube 12 of the sensor tube 10 and the proximal tube 22 of the OTW tube 20 can be made of a resin having high rigidity. Examples of the resin having high rigidity include nylon resin, polyester resin, and 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, 31, and 32. 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.

[0056] As shown in Fig. 1, in the catheter 1 of this embodiment, a portion on the proximal side of the flexible proximal tube 32 of the RX tube 30 is overlapped with the highly rigid proximal tube 12 and proximal tube 22, 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. 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 distal tube 31 and proximal tube 32 of the RX tube 30 may have a multi-layer structure in which tubes made of different materials are overlapped.

[0057] The distal tip 40, the first marker 41, and the second marker 42 can be formed from a radiopaque resin or metal material. Examples of radiopaque resin materials include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin, mixed with a radiopaque material such as bismuth trioxide, tungsten, or barium sulfate. Examples of radiopaque metal materials include gold, platinum, tungsten, and alloys containing these elements. The distal tip 40, the first marker 41, and the second marker 42 may be formed from the same material or different materials. If the distal tip 40, the first marker 41, and the second marker 42 are made of metal, images of the distal tip 40, the first marker 41, and the second marker 42 can be obtained not only in an angioimage but also in images acquired by the sensor 70.

[0058] The branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the outer cylindrical member 64, the inner cylindrical member 67, 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 outer cylindrical member 64, the inner cylindrical member 67, the connector 65, and the connector 25 may be made of the same material or different materials.

[0059] The heat-shrinkable tube 90 can be made of a nylon-based elastomer resin having thermoplastic properties. An example of a nylon-based elastomer resin having thermoplastic properties is polyamide elastomer. The heat-shrinkable tube 90 has the property of shrinking without melting when heated within a predetermined temperature range. The heat-shrinkable tube 90 has improved adhesive properties when heated compared to when not heated. Adhesive properties refer to the property of easily adhering to other substances. The heat-shrinkable tube 90 may be made of polyolefin, FEP, or silicone. FEP stands for Fluorinated Ethylene Propylene.

[0060] The first outer tube 50 and the second outer tube 80 can be 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.

[0061] 8 and 9 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 that has developed in a blood vessel using an antegrade approach. The catheter 1 may also be used in a retrograde approach, or for procedures other than CTO recanalization.

[0062] (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) As shown in FIG. 8 , the surgeon inserts the proximal end of the workhorse wire 200 through 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. (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. 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 along the workhorse wire 200. (a4) As shown by the white arrow in FIG. 9 , the surgeon grasps the connector 65 and slides it back and forth to adjust the position of the probe 72 of the sensor 70 within the movable range MR. The surgeon aligns the CTO and the distal opening 201 while checking the orientation of the CTO and the distal opening 201 by checking the image displayed on the console terminal. The term "position" refers to the position in the extension direction of the blood vessel. The term "orientation" refers to the orientation in the circumferential direction of the inner wall of the blood vessel. (a5) As indicated by the diagonal arrow in FIG. 9 , the surgeon inserts the distal end of the treatment device 300 from 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. (a6) The surgeon adjusts the position of the probe 72 of the sensor 70 within the movable range MR as needed, while checking the image displayed on the console terminal, and treats the CTO using the treatment device 300. The treatment device 300 can be any device, such as a plasma guidewire or a penetration guidewire.

[0063] 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 corresponds to the "first tube," and the sensor lumen 10L corresponds to the "first lumen." The OTW tube 20 corresponds to the "second tube," and the OTW lumen 20L corresponds to the "second lumen." The RX tube 30 corresponds to the "third tube," and the RX lumen 30L corresponds to the "third lumen." The distal tube 31 corresponds to the "distal third tube," and the proximal tube 32 corresponds to the "proximal third tube." The distal opening 201 of the OTW tube 20 corresponds to the "first distal opening," the proximal opening 202 corresponds to the "first proximal opening," and the side opening 203 corresponds to the "side opening." The distal opening 301 of the RX tube 30 corresponds to the "second distal opening", the proximal opening 302 corresponds to the "second proximal opening", the third opening 303 corresponds to the "third opening", and the fourth opening 304 corresponds to the "fourth opening".

[0064] Figure 10 is an enlarged view of the tip end side of the catheter 1. In Figure 10, the membrane 95 is shown with dotted hatching. Figure 11 is a cross-sectional view of the catheter 1 taken along line F-F in Figure 10. The balloon in Figure 11 shows an enlarged view of the joint between the sensor tube 10 and the RX tube 30. The configuration of the tip end side of the catheter 1 will be further described using Figures 10 and 11.

[0065] 10 , the sensor tube 10 and the RX tube 30 are connected by a membrane 95 on the distal side of the distal opening 201. In other words, the membrane 95 connects the portion of the sensor tube 10 located distally of the distal opening 201 with the portion of the RX tube 30 located distally of the distal opening 201. In this embodiment, the membrane 95 is provided over the entire area between the first marker 41 and the second marker 42 in the longitudinal direction of the catheter 1. The section in which the membrane 95 is provided coincides with the section in which the acoustic window AW is provided.

[0066] The film 95 is formed from a coating agent. In this embodiment, the coating agent includes a base agent and a top-coating agent. The base agent is an agent for improving the adhesion of the top-coating agent to the resin tube. Examples of the base agent that can be used include acrylic resin, acrylamide, and carboxylic acid. The top-coating agent is an agent for imparting hydrophilicity. Examples of the top-coating agent that can be used include well-known hydrophilic resins such as hyaluronic acid.

[0067] As shown in FIG. 11 , the film 95 includes an undercoat layer 96 and a topcoat layer 97. The undercoat layer 96 is a layer formed from a base agent. The undercoat layer 96 thinly covers the outer peripheral surface 11o of the distal tube 11 of the sensor tube 10 and the outer peripheral surface 31o of the distal tube 31 of the RX tube 30 while contacting the outer peripheral surfaces 11o, 31o. As shown in the dashed bubble in FIG. 11 , the undercoat layer 96 penetrates between the outer peripheral surface 11o of the distal tube 11 and the outer peripheral surface 31o of the distal tube 31 at the portion where the distal tube 11 and the distal tube 31 are adjacent to each other. In other words, the undercoat layer 96 covers the vicinity of the contact point between the outer peripheral surface 11o of the distal tube 11 and the outer peripheral surface 31o of the distal tube 31, thereby joining the distal tube 11 and the distal tube 31. The topcoat layer 97 is a layer formed from a top coating agent. The topcoat layer 97 thinly covers the outer peripheral surface 96o of the undercoat layer 96 while contacting the outer peripheral surface 96o. As shown in the dashed line bubble in Fig. 11 , the topcoat layer 97 does not penetrate between the outer peripheral surface 11o of the distal tube 11 and the outer peripheral surface 31o of the distal tube 31. In other words, in the example of Fig. 11 , it can be said that the base agent of the hydrophilic coating bonds the distal tube 11 of the sensor tube 10 and the distal tube 31 of the RX tube 30.

[0068] 11 , the common circumferential tangents EC1 and EC2 of the distal tube 11 of the sensor tube 10 and the distal tube 31 of the RX tube 30 are indicated by dashed lines. The common circumferential tangent EC1 is also referred to as the "first common circumferential tangent EC1," and the common circumferential tangent EC2 is also referred to as the "second common circumferential tangent EC2." As shown in the figure, a gap SP1 is formed between the outer peripheries of the distal tube 11 and the distal tube 31 and the first common circumferential tangent EC1. Similarly, a gap SP2 is formed between the outer peripheries of the distal tube 11 and the distal tube 31 and the second common circumferential tangent EC2. The presence of the gaps SP1 and SP2 means that, in a cross section of the catheter 1 including the acoustic window AW, the contour of the catheter 1 has a constriction at the adjacent portion of the two adjacent tubes 11 and 31.

[0069] The method for forming the film 95 can be, for example, the following methods b1 to b8. (b1) The operator prepares a base liquid and a top coat liquid. (b2) The operator aligns the distal tube 11 of the sensor tube 10 and the distal tube 31 of the RX tube 30 and immerses at least the entire portion where the film 95 is intended to be formed in the base liquid. The operator may immerse the entire distal end of the catheter 1 beyond the second marker 42 in the base liquid, or the entire catheter 1 from the distal end to the proximal end in the base liquid. At this time, the distal tip 40, first marker 41, and second marker 42 may already be formed at the distal end of the RX tube 30, or the tubes 10, 20, and 30 may be fixed by the first outer tube 50 or the like. (b3) By step a2, the base liquid enters the gap between the adjacent distal tube 11 and distal tube 31 due to surface tension. (b4) The worker uses a cleaning tissue or the like to absorb excess base agent liquid on the outer peripheral surfaces of the distal tube 11 and the distal tube 31, thereby controlling the film thickness of the undercoat layer 96. (b5) The worker dries the base agent liquid. This forms the undercoat layer 96. (b6) As in step b2, the worker immerses at least the entire area where the film 95 is intended to be formed in the top agent liquid. (b7) The worker uses a cleaning tissue or the like to absorb excess top agent liquid on the outer peripheral surface of the undercoat layer 96, thereby controlling the film thickness of the topcoat layer 97. (b8) The worker dries the top agent liquid. This forms the topcoat layer 97.

[0070] As described above, the coating agent of this embodiment is an agent for imparting hydrophilicity. Therefore, the film 95 swells in a wet state when wet with a liquid, and its flexibility is improved compared to a non-wet state. The non-wet state means that the film 95 is not wet and is dry. The film thickness of the film 95 in the wet state is about 20 times that of the film 95 in the non-wet state. When the film 95 is wet, it absorbs and encapsulates moisture, turning into a jelly-like state.

[0071] The undercoat layer 96 of the film 95 is thin due to the properties of the base agent, which improves the adhesion of the top coat. However, it has high adhesion to the distal tube 11 and the distal tube 31, is resistant to mechanical loads, and does not impair the flexibility of the distal tube 11 and the distal tube 31 even after the undercoat layer 96 is formed. In this embodiment, the distal tube 11 of the sensor tube 10 and the distal tube 31 of the RX tube 30 are bonded together using such a film 95. This avoids the disadvantages that arise when bonding tubes using adhesives, when bonding tubes using heat fusion, and when bonding tubes using an outer tube. Disadvantages that arise when bonding tubes using adhesives include, for example, reduced flexibility and operability due to hardening of the adhesive bonded portion, and reduced acoustic characteristics of the acoustic window AW due to the provision of an adhesive layer. Disadvantages that arise when bonding tubes using heat fusion include, for example, tube deformation due to heating and reduced acoustic characteristics of the acoustic window AW due to tube deformation. Disadvantages of using an outer tube to connect tubes include an increase in diameter and a deterioration in the acoustic characteristics of the acoustic window AW, which can cause problems such as darkening or defects in the image obtained by the sensor.

[0072] Fig. 12 is a diagram illustrating an approach using the distal opening 201 of the catheter 1. Fig. 12 illustrates the catheter 1 inserted into a patient's blood vessel 500, as well as the false lumen 501, true lumen 502, and CTO 509 of the blood vessel 500. The X, Y, and Z axes of the catheter 1 in Fig. 12 correspond to the X, Y, and Z axes in Fig. 1. Fig. 13 is a diagram illustrating the catheter 1 as viewed from direction A in Fig. 12. In Figs. 12 and 13, the membrane 95 of the catheter 1 is indicated by dot hatching.

[0073] In steps a5 and a6 described above, when the surgeon protrudes the distal end of the treatment device 300 from the distal end opening 201, depending on the orientation of the catheter 1 within the blood vessel 500, the distal end of the treatment device 300 may not face the true lumen 502 but may face the adventitia side of the blood vessel 500, as shown by the dashed line in FIG. 12 . Because the catheter 1 is long, even in such a case, it is not easy to change the orientation of the distal end opening 201 by rotating the catheter 1. In such a case, the surgeon directs the distal end of the treatment device 300 toward the sensor tube 10 and the RX tube 30, as shown in FIG. 13 , and pierces the membrane 95 with the distal end of the treatment device 300. During the procedure, the catheter 1 is wetted with blood within the blood vessel 500, turning into a jelly-like substance and exhibiting improved flexibility compared to a non-wet state. Therefore, the surgeon can easily break through the membrane 95 by gently pushing the treatment device 300 toward the gap between the sensor tube 10 and the RX tube 30. After breaking through the membrane 95, the surgeon can make the treatment device 300 reach the true lumen 502 by passing the tip of the treatment device 300 through the gap created between the sensor tube 10 and the RX tube 30.

[0074] Fig. 14 is a diagram illustrating an approach using the side opening 203 of the catheter 1. Similar to Fig. 12, Fig. 14 illustrates the catheter 1 inserted into a patient's blood vessel 500, and the false lumen 501, true lumen 502, and CTO 509 of the blood vessel 500. The X, Y, and Z axes of the catheter 1 in Fig. 14 correspond to the X, Y, and Z axes in Fig. 1. Fig. 15 is a transverse cross-sectional view of the catheter 1 and blood vessel 500 taken along line G-G in Fig. 14.

[0075] In steps a5 and a6 described above, instead of protruding the treatment device 300 from the distal opening 201 to break through the membrane 95, the surgeon may approach the treatment device 300 from the side opening 203. Specifically, as shown in FIG. 14 , the surgeon temporarily pulls back the distal end of the treatment device 300 from the distal opening 201 and protrudes the distal end of the treatment device 300 from the side opening 203. As described in FIG. 1 , the position of the side opening 203 and the surrounding area of ​​the side opening 203 are gaps 33 where no RX tube 30 is present. Furthermore, as described in FIG. 4 , the side opening 203 is located on the gap 33 side in the circumferential direction of the OTW tube 20. Therefore, the distal end of the treatment device 300 protruding from the side opening 203 can pass through the gap 33 and reach the true lumen 502 without being interfered with by the RX tube 30. 15 , the surgeon passes the distal end of the treatment device 300 between the sensor tube 10 and the work horse wire 200 passed through the RX lumen 30L, and reaches the true lumen 502. The surgeon may also reach the distal end of the treatment device 300 from outside the work horse wire 200 passed through the RX lumen 30L, and reach the true lumen 502. When there is no need to further advance the catheter 1 within the blood vessel 500, the surgeon may remove the work horse wire 200 from the RX lumen 30L. This allows the surgeon to more easily reach the distal end of the treatment device 300 into the true lumen 502.

[0076] As described above, according to the catheter 1 of the first embodiment, the sensor tube 10 and the RX tube 30 are connected by the membrane 95 on the distal side of the distal opening 201 of the OTW tube 20. Therefore, as described in Fig. 12 , when an operator inserts the treatment device 300 into the OTW lumen 20L and causes the distal end of the treatment device 300 to protrude from the distal opening 201, even if the target site of treatment is located on the side of the sensor tube 10 and the RX tube 30, the operator can pass the distal end of the treatment device 300 between the sensor tube 10 and the RX tube 30 and reach the target site by piercing the membrane 95 with the distal end of the treatment device 300. As a result, a catheter 1 can be provided that makes it easy to direct the treatment device 300 in the OTW lumen 20L toward the target site of treatment.

[0077] According to the catheter 1 of the first embodiment, the sensor tube 10 and the RX tube 30 are joined by a membrane 95, which avoids the disadvantages that arise when joining the tubes 10, 30 using adhesive, when joining the tubes 10, 30 using heat fusion, and when joining the tubes 10, 30 using an outer tube.

[0078] 12 , when the operator inserts the catheter 1 into the blood vessel 500 and the membrane 95 becomes wet with blood, the membrane 95 swells and becomes more flexible than when it is not wet. This allows the operator to easily break through the membrane 95 with the tip of the treatment device 300 during a procedure using the catheter 1.

[0079] According to the catheter 1 of the first embodiment, as described in Fig. 1, a side opening 203 is formed between the distal opening 201 and the proximal opening 202 of the OTW tube 20. Therefore, as described in Fig. 14, the surgeon can protrude the distal end of the treatment device 300 from the side opening 203 instead of the distal opening 201. As a result, the usability of the catheter 1 can be further improved.

[0080] 1 , in the catheter 1 of the first embodiment, a gap 33 is present in the RX tube 30 between the third opening 303 provided distally of the side opening 203 of the OTW tube 20 and the fourth opening 304 provided proximally of the side opening 203 of the OTW tube 20. That is, the gap 33 is present in the RX tube 30 at the position of the side opening 203 of the OTW tube 20 and a position in the vicinity thereof. Therefore, as described in FIG. 14 , when the surgeon protrudes the distal end of the treatment device 300 from the side opening 203, interference between the distal end of the treatment device 300 and the RX tube 30 can be suppressed. As a result, the treatment device 300 in the OTW lumen 20L can be more easily directed toward the target site of treatment.

[0081] According to the catheter 1 of the first embodiment, as described in Fig. 4 , the side opening 203 of the OTW tube 20 is located on the side of the gap 33 in the circumferential direction of the OTW tube 20. Therefore, as described in Fig. 14 , when the surgeon protrudes the distal end of the treatment device 300 from the side opening 203, it is possible to further prevent the distal end of the treatment device 300 from interfering with the RX tube 30. As a result, it is possible to more easily direct the treatment device 300 in the OTW lumen 20L in the direction of the target site for treatment.

[0082] According to the catheter 1 of the first embodiment, the RX tube 30 has the distal tube 31 and the proximal tube 32, and therefore the RX tube 30 having the gap 33 between the third opening 303 and the fourth opening 304 can be formed by the two tubes 31, 32. Furthermore, in the catheter 1 of this embodiment, the proximal tube 32 is located closer to the proximal end than the gap 33, and therefore, compared to a configuration in which the proximal tube 32 is not present, when the work horse wire 200 is passed through the RX lumen 30L, the catheter 1 can be passed through the blood vessel more easily.

[0083] According to the catheter 1 of the first embodiment, the first material and the second material have different acoustic impedances, so that the sensor tube 10 and the RX tube 30 can be easily distinguished from each other in an image acquired by the sensor 70. The first material and the third material have different acoustic impedances, so that the sensor tube 10 and the OTW tube 20 can be easily distinguished from each other in an image acquired by the sensor 70. The second material and the third material have different acoustic impedances, so that the RX tube 30 and the OTW tube 20 can be easily distinguished from each other in an image acquired by the sensor 70.

[0084] Second Embodiment Fig. 16 is a cross-sectional view of a catheter 1A according to a second embodiment. Fig. 16 shows a cross-section of the catheter 1A, including the acoustic window AW, taken along line F-F in Fig. 10. The catheter 1A according to the second embodiment has a membrane 95A instead of the membrane 95 in the configuration described in the first embodiment.

[0085] The film 95A is formed from a single-component coating agent and bonds the distal tube 11 of the sensor tube 10 and the distal tube 31 of the RX tube 30. The coating agent forming the film 95A is composed of a single agent that functions as both a base agent and a top agent. Examples of such coating agents include polyvinylpyrrolidone (PVP). Similar to the undercoat layer 96 of the first embodiment, the film 95A thinly covers the outer peripheral surfaces 11o, 31o of the distal tube 11 and the distal tube 31 while contacting the outer peripheral surfaces 11o, 31o. The film 95A penetrates into the gap between the adjacent portions of the distal tube 11 and the distal tube 31, i.e., between the outer peripheral surfaces 11o and 31o.

[0086] As described above, the configuration of the membrane 95A can be modified in various ways, and it may be a single-layer configuration formed with a coating agent consisting of only one agent. Because the coating agent forming the membrane 95A functions as both a base agent and a top agent, the membrane 95A has properties similar to those of the undercoat layer 96 described in the first embodiment. Therefore, the catheter 1A of the second embodiment can also achieve the same effects as the first embodiment. The number of layers constituting the membrane 95A may be determined arbitrarily. For example, if the membrane 95A has a three-layer configuration, the membrane 95A includes an undercoat layer formed by applying a first base agent, an intermediate layer formed by applying a second base agent, and a topcoat layer formed by applying a top agent. The membrane 95A may also be formed with a hydrophobic coating agent instead of a hydrophilic coating agent. This configuration can also achieve the same effects as the first embodiment.

[0087] <Third embodiment> Fig. 17 is a cross-sectional view of a catheter 1B according to a third embodiment. Fig. 17 shows a cross-section of the catheter 1B, including the acoustic window AW, taken along line F-F in Fig. 10. The catheter 1B according to the third embodiment includes a membrane 95B instead of the membrane 95 in the configuration described in the first embodiment.

[0088] The film 95B is not a coating agent but is formed from a nylon, polyamide, or polyethylene-based resin, and bonds the distal tube 11 of the sensor tube 10 to the distal tube 31 of the RX tube 30. Similar to the undercoat layer 96 of the first embodiment, the film 95B thinly covers the outer peripheral surfaces 11o, 31o of the distal tube 11 and the distal tube 31 while contacting the outer peripheral surfaces 11o, 31o. The film 95B penetrates into the gap between the adjacent portions of the distal tube 11 and the distal tube 31, i.e., between the outer peripheral surfaces 11o and 31o.

[0089] As described above, the configuration of the membrane 95B can be modified in various ways, and it may be formed of a material other than the coating agent as long as it can be broken through by the tip of the treatment device 300 during use. The membrane 95B does not have the property of swelling in a wet state. The membrane 95B does not have the property of becoming more flexible in a wet state compared to a non-wet state. The catheter 1B of the third embodiment as described above can also achieve the same effects as those of the first embodiment described above.

[0090] 18 is an explanatory diagram illustrating the configuration of a catheter 1C according to a fourth embodiment. The catheter 1C according to the fourth embodiment includes an RX tube 30C instead of the RX tube 30 in the configuration described in the first embodiment.

[0091] The RX tube 30C has only the distal tube 31 described in the first embodiment, and does not have the proximal tube 32 described in the first embodiment. In step a2 of the procedure using the catheter 1C, the surgeon can deliver the catheter 1C by inserting the proximal end of the work hose wire 200 through the distal opening 301 of the catheter 1C and pulling it out through the third opening 303. As described above, in this embodiment, the overall length of the RX lumen 30L is shorter than in the first embodiment. The third opening 303 of the RX tube 30C is located further distally than the side opening 203 of the OTW tube 20. Therefore, in the catheter 1C, as in the first embodiment, a gap 33 where the RX tube 30C does not exist is present at the position of the side opening 203 and in the vicinity of the side opening 203.

[0092] As described above, the configuration of the RX tube 30C can be modified in various ways, and the RX tube 30C may be provided only on the distal side of the side opening 203 of the OTW tube 20 to facilitate operation of a treatment device protruding from the side opening 203. The catheter 1C of the fourth embodiment as described above can also achieve the same effects as those of the first embodiment described above.

[0093] <Fifth embodiment> Figure 19 is an explanatory diagram of an RX tube 30D of a fifth embodiment. A catheter 1D of the fifth embodiment includes an RX tube 30D instead of the RX tube 30 in the configuration described in the first embodiment. For convenience of explanation, Figure 19 illustrates only the RX tube 30D extracted from the catheter 1D. The X, Y, and Z axes in Figure 19 correspond to the X, Y, and Z axes in Figure 1.

[0094] The RX tube 30D is composed of a single tube as shown in FIG. 19 , instead of the distal tube 31 and proximal tube 32 described in the first embodiment. The RX tube 30D has a notch 38 formed by cutting off a thick portion of the RX tube 30D over a predetermined range in the circumferential direction r1 and a predetermined range in the longitudinal direction r2. The distal end of the notch 38 forms a third opening 303 through which the RX lumen 30L is opened to the outside. The proximal end of the notch 38 forms a fourth opening 304 through which the RX lumen 30L is opened to the outside. Between the third opening 303 and the fourth opening 304, the RX tube 30D is connected by a thin bridge portion 39, and the remaining portion is a gap 33D. As such, the gap 33D in this embodiment does not refer to a portion where the RX tube 30D is absent, but refers to a portion where only the bridge portion 39 of the RX tube 30D is present. The predetermined range in the circumferential direction r1 can be set arbitrarily. The predetermined range in the circumferential direction r1 is preferably 300 degrees or greater. The predetermined range in the longitudinal direction r2 is equal to the distance between the tip of the third opening 303 and the base end of the fourth opening 304. The predetermined range in the longitudinal direction r2 is preferably greater than the length of the side opening 203 in the longitudinal direction of the catheter 1D. The inclination of the third opening 303 and the fourth opening 304 and the positions of the third opening 303 and the fourth opening 304 are as described in the first embodiment.

[0095] As described above, the configuration of the RX tube 30D can be modified in various ways, and the gap 33D can be realized by providing a notch 38 in a single tube. The catheter 1D of the fifth embodiment as described above can also achieve the same effects as the first embodiment. According to the catheter 1D of the fifth embodiment, the RX tube 30D having the gap 33D between the third opening 303 and the fourth opening 304 can be formed from a single tube. Therefore, the third opening 303 and the fourth opening 304 of the RX tube 30D can be processed before being assembled to the catheter 1D, facilitating the manufacture of the catheter 1D.

[0096] <Sixth embodiment> Figure 20 is an enlarged view of the distal end side of a catheter 1E of a sixth embodiment. The catheter 1E of the sixth embodiment has an RX tube 30E instead of the RX tube 30 in the configuration described in the first embodiment. The RX tube 30E consists of a single tube shown in Figure 20 instead of the distal tube 31 and proximal tube 32 described in the first embodiment. No notch is formed in the RX tube 30E. Therefore, the catheter 1E does not have the third opening 303, the fourth opening 304, and the gap 33 described in the first embodiment.

[0097] As described above, the configuration of the catheter 1E can be modified in various ways, and the gap 33 need not be located at the position of the side opening 203 of the OTW tube 20. Even with this catheter 1E, in steps a5 and a6, the surgeon can pass the distal end of the treatment device 300 through the gap formed between the sensor tube 10 and the RX tube 30E by piercing the membrane 95 with the treatment device 300 protruding from the distal opening 201. Furthermore, in steps a5 and a6, the surgeon can push the treatment device 300 protruding from the side opening 203 along the outer circumferential surface of the RX tube 30E, thereby allowing the distal end of the treatment device 300 to reach the target site of treatment located on the opposite side from the side toward which the distal opening 201 faces. Therefore, the catheter 1E of the sixth embodiment as described above can also achieve the same effects as those of the first embodiment described above.

[0098] 21 is an enlarged view of the distal end side of a catheter 1F of a seventh embodiment. The catheter 1F of the seventh embodiment further includes an OTW tube 20F instead of the OTW tube 20 in the configuration described in the sixth embodiment. The OTW tube 20F does not have the side opening 203 described in the first embodiment. Therefore, the catheter 1F does not have the third opening 303, the fourth opening 304, the gap 33, and the side opening 203 described in the first embodiment.

[0099] As described above, the configuration of the catheter 1F can be modified in various ways, and the OTW tube 20 does not need to have the side opening 203. Even when such a catheter 1F is used, the surgeon can pass the distal end of the treatment device 300 through the gap formed between the sensor tube 10 and the RX tube 30E in steps a5 and a6 by piercing the membrane 95 with the treatment device 300 protruding from the distal opening 201. Therefore, the catheter 1F of the seventh embodiment as described above can also achieve the same effects as those of the first embodiment described above.

[0100] <Modifications of this embodiment> The present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof. For example, the following modifications are also possible.

[0101] [Modification 1] In the above first to seventh embodiments, one example of the configuration of the catheters 1, 1A to 1F is shown. The configuration of the catheters 1, 1A to 1F can be modified in various ways.

[0102] For example, the membranes 95, 95A, and 95B may be provided only in a partial section between the first marker 41 and the second marker 42. In other words, the membranes 95, 95A, and 95B may be provided only in a partial section in the longitudinal direction of the acoustic window AW. For example, in a cross section of the catheter 1 including the acoustic window AW as shown in FIG. 11 , the gap SP1 does not have to be provided between the outer peripheries of the distal tube 11 and the distal tube 31 and the first common circumferential tangent EC1. Similarly, the gap SP2 between the outer peripheries of the distal tube 11 and the distal tube 31 and the second common circumferential tangent EC2 may also be omitted.

[0103] For example, the methods for forming the film 95 described in steps b1 to b8 are merely examples, and various modifications are possible. For example, in at least one of steps b2 and b6, instead of immersing the sensor tube 10 and the RX tube 30 in liquid, the operator may apply a base agent or top agent liquid to the surfaces of the sensor tube 10 and the RX tube 30 by spraying it onto them. For example, in at least one of steps b4 and b7, the operator may omit controlling the film thickness by siphoning up the liquid.

[0104] For example, at least two of the sensor tube 10, the OTW tube 20, and the RX tube 30 may be made of materials having the same acoustic impedance. Even if the three tubes 10, 20, and 30 are made of materials having the same acoustic impedance, the sensor tube 10, the OTW tube 20, and the RX tube 30 can be distinguished from one another in the image acquired by the sensor 70 by making the thicknesses of the three tubes 10, 20, and 30 different from one another.

[0105] For example, the sensor tube 10 may be formed as a single tube without having the distal tube 11 and the proximal tube 12. Similarly, the OTW tube 20 may be formed as a single tube without having the distal tube 21 and the proximal tube 22. For example, the sensor tube 10, the OTW tube 20, and the RX tube 30 may be integrally molded. Even in the case of integral molding, the sensor tube 10 and the RX tube 30 can be formed as separate tubes at a position distal to the distal opening 201, and as long as they are joined by the membrane 95, the same effects as in the first embodiment can be achieved.

[0106] For example, the distal opening 201 of the OTW tube 20 may be circular with the distal end of the OTW tube 20 cut vertically. Similarly, at least one of the proximal opening 302, the third opening 303, and the fourth opening 304 of the RX tube 30 may also be circular with the end of the RX tube 30 cut vertically.

[0107] For example, the sensor 70 is built into the sensor lumen 10L of the sensor tube 10 and is configured to be non-removable 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. 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.

[0108] For example, at least one of the distal tip 40, the first marker 41, and the second marker 42 may be omitted. The arrangement and shape of these markers can be changed as desired. For example, 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 positioned away from the proximal end of the distal tip 40. For example, at least one of the distal tip 40, the first marker 41, and the second marker 42 may be positioned on a tube other than the RX tube 30. For example, 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. For example, at least one of the first marker 41 and the second marker 42 may have a shape other than a circular ring.

[0109] 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, the shapes of the branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the outer cylindrical member 64, the inner cylindrical member 67, the connector 65, and the connector 25 described above are merely examples and may be modified as desired. For example, at least a portion of the branch connector 60, the first reinforcing member 61, the second reinforcing member 62, the outer cylindrical member 64, and the inner cylindrical member 67 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 outer cylindrical member 64 may be formed of a transparent material, and the inner cylindrical member 67 may be provided with a mechanism for assisting 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. The assisting mechanism may be, for example, a scale provided at predetermined intervals in the longitudinal direction or a scale provided at predetermined intervals in the circumferential direction. Instead of the scale, a stopper may be used.

[0110] [Modification 2] The configurations of the catheters 1, 1A to 1F of the first to seventh embodiments and the configuration of the catheters 1, 1A to 1F of Modification 1 may be combined as appropriate. For example, the membrane 95A described in the second embodiment may be employed in the catheters 1C to 1F described in any of the fourth to seventh embodiments, or the membrane 95B described in the third embodiment may be employed. For example, the side opening 203 may be omitted in the catheter 1C described in the fourth embodiment, as in the seventh embodiment.

[0111] This aspect has been described above based on embodiments and modifications. The above-described embodiments of the aspect 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. If a technical feature is not described as essential in this specification, it may be deleted as appropriate.

Claims

1. A medical device (1, 1A-1F) comprising: a first tube (10) having a first lumen; a second tube (20, 20F) arranged alongside the first tube (10) and having a second lumen, the second tube (20, 20F) having a first distal end opening (201) formed at the distal end of the second tube (20, 20F) for connecting the second lumen to the outside; a third tube (30, 30C, 30D, 30E) arranged alongside the first and second tubes (20, 20F) and having a third lumen; and a membrane (95, 95A, 95B) connecting a portion of the first tube (10) located distally of the first distal end opening (201) and a portion of the third tube (30, 30C, 30D, 30E) located distally of the first distal end opening (201); A medical device (1, 1A to 1F) comprising:

2. A medical device (1, 1A, 1C to 1F) according to claim 1, wherein the membrane (95, 95A) swells in a wet state when wetted with a liquid, and has improved flexibility compared to a non-wet state.

3. A medical device (1, 1A to 1E) according to claim 1 or claim 2, wherein a first base end opening (202) is formed at the base end of the second tube (20) to connect the second lumen to the outside, and a side opening (203) is formed on the side of the second tube (20) between the first tip end opening (201) and the first base end opening (202) to connect the second lumen to the outside.

4. A medical device (1, 1A to 1D) according to claim 3, wherein a second distal opening (301) connecting the third lumen to the outside is formed at the distal end of the third tube (30, 30C, 30D), and a second proximal opening (302) connecting the third lumen to the outside is formed at the proximal end of the third tube (30, 30C, 30D), and a third opening (303) connecting the third lumen to the outside and a fourth opening (304) connecting the third lumen to the outside are formed between the second distal opening (301) and the second proximal opening (302), and the third opening (303) is provided on the distal side of the side opening (203) of the second tube (20), and the fourth opening (304) is provided on the proximal side of the side opening (203) of the second tube (20), A medical device (1, 1A to 1D), wherein a gap (33, 33D) exists between the third opening (303) and the fourth opening (304) in the third tube (30, 30C, 30D).

5. A medical device (1, 1A to 1D) according to claim 4, wherein the side opening (203) of the second tube (20) is located on the side of the gap (33, 33D) in the circumferential direction of the second tube (20).

6. A medical device (1, 1A, 1B) according to claim 4 or 5, wherein the third tube (30) includes a distal third tube (31) disposed on the distal side, and a proximal third tube (32) disposed on the proximal side of the distal third tube (31) and at a position away from the distal third tube (31), the second distal opening (301) and the third opening (303) are provided in the distal third tube (31), and the fourth opening (304) and the second proximal opening (302) are provided in the proximal third tube (32).

7. A medical device (1D) according to claim 4 or claim 5, wherein a notch (38) is provided on the side of the third tube (30D) between the second distal opening (301) and the second proximal opening (302), by cutting away a thick portion of the third tube (30D) over a predetermined range in the circumferential and longitudinal directions, and the third opening (303) is the distal end of the notch (38), and the fourth opening (304) is the proximal end of the notch (38).

8. A medical device (1, 1A to 1F) according to any one of claims 1 to 7, wherein the first tube (10) is made of a first material, and the third tube (30, 30C, 30D, 30E) is made of a second material, and the first material and the second material have different acoustic impedances.

9. A medical device (1, 1A to 1F) according to claim 8, wherein the second tube (20, 20F) is formed of a third material, and the first material and the third material have different acoustic impedances.

10. A medical device (1, 1A to 1F) according to claim 9, wherein the second material and the third material have different acoustic impedances.

Images