Medical device

Abstract

The present invention provides a medical device comprising: a first tube having a first lumen; a second tube disposed beside the first tube and having a second lumen; and a third tube disposed beside the first and second tubes and having a third lumen. A leading end of the second tube is located farther on the basal side than the leading end of the first tube and farther on the basal side than the leading end of the third tube. A first leading-end opening is formed at the leading end of the second tube such that the second lumen communicates with the outside. At the position of the first leading-end opening, a gap is formed between the first and third tubes by the separation of the first and third tubes from each other.

Description

medical devices

[0001] The present invention relates to medical devices.

[0002] Medical devices for acquiring ultrasound images are known. For example, Patent Documents 1 to 4 describe catheters with an ultrasound transducer at the 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." Performing percutaneous procedures using such medical devices can improve the safety and efficiency of the procedures.

[0003] JP 2001-245886 A JP 2006-20944 A JP 2016-54797 A JP 2018-186946 A

[0004] The above-mentioned medical devices are configured with multiple lumens by combining multiple tubes or using multi-lumen tubes. However, with medical devices having 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 site for treatment, making the procedure difficult. Under such circumstances, changing the circumferential orientation of the medical device within the blood vessel (rotating the medical device within the blood vessel) entails the risk of expanding the false lumen if the medical device is located within the false lumen, which is not necessarily easy. The technologies described in Patent Documents 1 to 4 do not take this issue into consideration at all.

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

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

[0008] (1) According to one aspect of the present invention, there is provided a medical device comprising: a first tube having a first lumen; a second tube arranged alongside the first tube and having a second lumen; and a third tube arranged alongside the first and second tubes and having a third lumen, wherein the distal end of the second tube is arranged proximal to the distal end of the first tube and proximal to the distal end of the third tube, the distal end of the second tube having a first distal opening that connects the second lumen to the outside, and the first tube and the third tube being spaced apart from each other at the position of the first distal opening to form a gap between them.

[0009] According to this configuration, a gap is formed between the first tube and the third tube at the position of the first distal-end opening. Therefore, when a treatment device is inserted into the second lumen and its distal end protrudes from the first distal-end opening, even if the target site of treatment is located on the side of the first and third tubes, the treatment device can reach the target site by passing through the gap between the first and third tubes. 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 aspect, the distal end portion of the second tube may be inclined toward the gap as it approaches the distal end. According to this configuration, the distal end portion of the second tube is inclined toward the gap as it approaches the distal end. Therefore, the distal end portion of the treatment device protruding from the first distal end opening can be more smoothly passed through the gap between the first and third tubes.

[0011] (3) In the medical device of the above aspect, a portion of the distal end of the second tube may be inserted into the gap. With this configuration, since a portion of the distal end of the second tube is inserted into the gap between the first and third tubes, the distal end of the second tube is configured to be inclined toward the first and third tubes as it approaches the distal end. As a result, the distal end of the treatment device protruding from the first distal opening can be more smoothly passed through the gap between the first and third tubes.

[0012] (4) In the medical device of the above aspect, when the common circumferential tangent of the first tube and the third tube, which is closer to the second tube, is defined as a first common circumferential tangent in a cross section of the medical device at the position where the gap is formed, the length of the outer edge of the clamped portion, which is a portion of the distal end of the second tube located inside the first common circumferential tangent, may be at least half and at most two-half of the length of the outer edge of the distal end of the second tube. According to this configuration, the length of the outer edge of the clamped portion is at least half and at most two-half of the length of the outer edge of the distal end of the second tube, so that the distal end of the treatment device protruding from the first distal opening can be more smoothly passed through the gap between the first and third tubes.

[0013] (5) In the medical device of the above aspect, the width of the gap may be greater than the inner diameter of the distal end of the second tube × (½) and smaller than the inner diameter of the distal end of the second tube × (½). According to this configuration, the width of the gap is greater than the inner diameter of the distal end of the second tube × (½) and smaller than the inner diameter of the distal end of the second tube × (½). Therefore, even a treatment device having an outer diameter close to the inner diameter of the second tube can be used.

[0014] (6) In the medical device of the above aspect, the first distal opening may have an elliptical shape formed by obliquely cutting the distal end of the second tube. With this configuration, when the distal end of the treatment device is protruded from the first distal opening, even if the target site of treatment is located on the opposite side of the first and third tubes, the elliptical shape of the first distal opening makes it easier to direct the distal end of the treatment device toward the target site. As a result, the usability of the medical device can be further improved.

[0015] (7) In the medical device of the above embodiment, a portion of the outer circumferential surface of the first tube and a portion of the outer circumferential surface of the third tube may be in contact with each other distally of the gap, the distal end of the gap being located proximally of the distal end of the first tube and distally of the first distal opening, and the proximal end of the gap being proximally of the proximal end of the first distal opening. With this configuration, a portion of the outer circumferential surface of the first tube and a portion of the outer circumferential surface of the third tube are in contact with each other distally of the gap, allowing the distal end of the medical device to be thinned. Furthermore, the distal end of the gap is located proximally of the distal end of the first tube and distally of the distal end of the first distal opening, and the proximal end of the gap is located proximally of the proximal end of the first distal opening, making it easier to pass the distal end of a treatment device through the gap. This further improves the usability of the medical device.

[0016] (8) In the medical device of the above aspect, the distal end of the third lumen may be located distally of the distal end of the first lumen, and the distal end of the third lumen may be provided with a second distal opening communicating the third lumen with the outside. With this configuration, the distal end of the third lumen is located distally of the first lumen, allowing the distal end portion of the medical device to have a smaller diameter. Furthermore, the distal end of the third lumen is provided with a second distal opening communicating the third lumen with the outside, allowing the third lumen to be used as a lumen for a work horse wire.

[0017] (9) In the medical device of the above aspect, the second tube may further have a side opening in a side wall located proximally away from the first distal opening, the side opening communicating the second lumen with the outside. With this configuration, the second tube further has a side opening in a side wall located proximally away from the first distal opening, allowing the treatment device to protrude from the side opening as well. As a result, the usability of the medical device can be further improved.

[0018] (10) In the medical device of the above aspect, the side opening may be provided in a portion of the side wall of the second tube facing the gap. According to this configuration, the side opening is provided in a portion of the side wall of the second tube facing the gap. Therefore, the treatment device protruding from the side opening can be smoothly passed through the gap.

[0019] (11) 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.

[0020] (12) 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.

[0021] (13) 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.

[0022] 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.

[0023] 19 is an explanatory diagram illustrating the configuration of a medical device. FIG. 19 is an explanatory diagram illustrating the configuration of a medical device. FIG. 19 is a transverse cross-sectional view of the catheter taken along line A-A in FIG. 1. FIG. 19 is a transverse cross-sectional view of the catheter taken along line B-B in FIG. 1. FIG. 19 is a transverse cross-sectional view of the catheter taken along line CC in FIG. 1. FIG. 19 is a transverse cross-sectional view of the catheter taken along line D-D in FIG. 1. FIG. 19 is a transverse cross-sectional view of the catheter taken along line E-E in FIG. 1. FIG. 19 is a diagram illustrating a method of using a catheter. FIG. 19 is a diagram illustrating a method of using a catheter. FIG. 19 is an enlarged view of a portion of the distal end of a catheter. FIG. 19 is a transverse cross-sectional view of the catheter taken along line F-F in FIG. 19. FIG. 19 is a transverse cross-sectional view of the catheter taken along line G-G in FIG. 19. FIG. 19 is a diagram illustrating a state in which a therapeutic device is directed in a first direction. FIG. 19 is a diagram illustrating a state in which a therapeutic device is directed in a second direction. FIG. 19 is a diagram illustrating a state in which a catheter and a combined device are directed in a first procedure. FIG. 19 is a diagram illustrating a state in which a catheter and a combined device are directed in a second procedure. FIG. 19 is a diagram illustrating a state in which a catheter and a combined device are directed in a third procedure. FIG. 19 is an enlarged view of a portion of the distal end of a catheter of a second embodiment. FIG. 19 is an enlarged view of a portion of the distal end of a catheter of a third embodiment. FIG. 19 is a transverse cross-sectional view of a catheter taken along line H-H in FIG. Fig. 10 is a transverse cross-sectional view of a catheter according to a fourth embodiment. Fig. 11 is an enlarged view of a portion of the distal end side of a catheter according to a fifth embodiment.

[0024] 1 and 2 are explanatory diagrams illustrating an example of the configuration of a medical device 1. The medical device 1 of this embodiment is a catheter used to treat a lesion in a biological lumen, such as a chronic total occlusion (CTO) in a blood vessel. Hereinafter, the medical device 1 will also be referred to as a "catheter 1." As shown in FIGS. 1 and 2 , the catheter 1 includes a sensor tube 10, an over-the-wire (OTW) tube 20, a rapid exchange (RX) tube 30, a distal tip 40, a first marker 41, a second marker 42, a first outer tube 50, a branched connector 60, first to third reinforcing members 61 to 63, 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 in communication with the sensor lumen 10L. The proximal end of the inner cylindrical member 67 is fixed to the 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, which connects 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.

[0030] 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.

[0031] The OTW tube 20 is a cylindrical member (tubular body) having a long outer shape. The OTW tube 20 extends linearly along the longitudinal direction of the catheter 1, parallel to the sensor tube 10 and the RX tube 30, distal to the branch connector 60. An OTW lumen 20L (dashed line) for accommodating a treatment device (e.g., a plasma guidewire or a penetration guidewire) is formed inside the OTW tube 20. The OTW lumen 20L is a so-called over-the-wire (OTW) type lumen that does not have an opening in the portion that will be placed inside the biological lumen when the catheter 1 is in use.

[0032] The distal end of the OTW tube 20 is located proximal to the distal end of the sensor tube 10 and proximal to 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. The "oblique" refers to a direction that intersects the longitudinal direction of the catheter 1 and that extends toward the gap 400 from the proximal end toward the distal end. The distal opening 201 is inclined toward the gap 400 from the proximal end toward the distal end. This makes it easier for the therapeutic device to reach biological tissue surrounding the catheter 1 when the catheter 1 is in use. The proximal end of the OTW tube 20 is located distally of the proximal end of the sensor tube 10 and proximally of 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 of the OTW tube 20, from the distal end toward the proximal end. Details will be described later. The connector 25 has a proximal opening 202 that connects the proximal end of the OTW lumen 20L to the outside. The proximal opening 202 is a device insertion port for inserting a therapeutic device into the OTW lumen 20L.

[0033] 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.

[0034] 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 (indicated by a broken line) for accommodating a work hose wire is formed inside the RX tube 30. The RX lumen 30L includes the inner cavity of the RX tube 30 and the inner cavity of the distal tip 40. Therefore, the distal end of the RX lumen 30L is located closer to the distal end than the distal end of the sensor lumen 10L.

[0035] 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. 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.

[0036] 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.

[0037] 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 center 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 placing 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 (acquisition of image information) by the sensor 70.

[0038] As shown in Fig. 3, the sensor tube 10 (specifically, the distal tube 11) and the RX tube 30 are arranged in the cross section taken along line A-A. 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. As shown in Fig. 4, 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. In the B-B cross section, the three tubes 10, 20, and 30 are joined together with a portion of the outer circumferential surface of the sensor tube 10, a portion of the outer circumferential surface of the OTW tube 20, and a portion of the outer circumferential surface of the RX tube 30 in contact with each other. In addition, in a predetermined range located between the AA cross section and the BB cross section, a gap 400 is formed between the sensor tube 10 and the RX tube 30. The gap 400 will be described later.

[0039] As shown in FIG. 5 , in the cross section taken along line CC, 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-molded 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 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 FIG. 5 . As shown in FIG. 7 , 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 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.

[0040] 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. 3 to 7 , 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.

[0041] The outer shape of the catheter 1 in the A-A cross section and the B-B cross section follows the contours of the two tubes 10, 30 (or the three tubes 10, 20, 30) arranged next to each other, with a constriction (recess) formed in the adjacent portion of each tube. 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 (rounded-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.

[0042] 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.

[0043] 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.

[0044] 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 5 and 6, the first outer tube 50 has an outer shape like a rounded triangle, and has thick-walled portions melt-molded along the outer peripheral surfaces of the three tubes 10, 20, and 30.

[0045] 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. 7, the second outer tube 80 has an elliptical outer shape and has a thick-walled portion that is melt-molded along the outer peripheral surfaces of the two tubes 10 and 20.

[0046] 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.

[0047] 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 (device insertion port) is formed at the proximal end of the connector 25, connecting the proximal end of the OTW lumen 20L to the outside.

[0048] 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 inserted into 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 cylindrical member 67 (in other words, the inner cylindrical 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 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 communicates the proximal end of the sensor lumen 10L and the proximal end of the lumen of the inner cylindrical member 67 with the outside. The lumen of the inner cylindrical member 67 is part of the sensor lumen 10L.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In the catheter 1 of this embodiment, a section is provided in which a proximal portion of the flexible RX tube 30 overlaps with the highly rigid proximal tube 12 and proximal tube 22 ( FIG. 1 ), thereby achieving a gradual change in stiffness of the catheter 1. The gradual change in stiffness of the catheter 1 can also be said to reduce the stiffness gap of the catheter 1. This makes it possible to suppress kinking of the catheter 1. Note that one or more of the distal tube 11 and proximal tube 12 of the sensor tube 10, the distal tube 21 and proximal tube 22 of the OTW tube 20, and the RX tube 30 may have a multi-layer structure in which tubes made of different materials are overlapped.

[0054] 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. 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.

[0055] 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.

[0056] The heat-shrinkable tube 90 is made of a thermoplastic nylon-based elastomer resin (e.g., polyamide elastomer). The heat-shrinkable tube 90 has the property of shrinking without melting when heated within a predetermined temperature range. Furthermore, the heat-shrinkable tube 90 has improved adhesiveness (the ability to easily stick to other substances) when heated compared to when not heated. The heat-shrinkable tube 90 may also be made of polyolefin, FEP (Fluorinated Ethylene Propylene), or silicone.

[0057] 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.

[0058] 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 (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 recanalization of a CTO.

[0059] (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. 8 ). (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 in the forward and backward directions (in the direction of the white arrow in FIG. 9 ) 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, the surgeon aligns the CTO with the distal opening 201 while confirming the orientation of the CTO and the distal opening 201. The term "position" refers to the position in the extension direction of the blood vessel. The term "orientation" refers to the orientation circumferentially around the inner wall of the blood vessel. (a5) 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 ( FIG. 9 ). (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. The term "position" refers to the position in the extension direction of the blood vessel. The term "orientation" refers to the orientation circumferentially around the inner wall of the blood vessel. As described above, the treatment device 300 can be any device such as a plasma guidewire or a penetration guidewire.

[0060] 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 opening 201 of the OTW lumen 20L corresponds to the "first distal opening." The distal opening 301 of the RX lumen 30L corresponds to the "second distal opening." In this embodiment, "same" and "equal" do not necessarily mean strict 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.

[0061] Figure 10 is an enlarged view of a portion of the distal end of the catheter 1. The sensor lumen 10L, the OTW lumen 20L, and the RX lumen 30L are not shown in Figure 10. In Figure 10, portions of the sensor tube 10 and the RX tube 30 located behind the OTW tube 20 are shown by dashed lines.

[0062] At the tip of the catheter 1, a gap 400 is formed between the sensor tube 10 (first tube) and the RX tube 30 (third tube). The gap 400 is a space formed between the outer circumferential surfaces of the sensor tube 10 and the RX tube 30 due to the separation of these outer circumferential surfaces. In the example of Fig. 10, the sensor tube 10 moves straight along the longitudinal direction of the catheter 1, while a portion of the RX tube 30 curves in a direction away from the sensor tube 10 (-Y axis direction) and separates from the sensor tube 10, thereby forming the gap 400.

[0063] As shown in Fig. 10 , the gap 400 is formed at the position of the distal opening 201 (first distal opening) that communicates the OTW lumen 20L with the outside. Here, the position of the distal opening 201 refers to any range including the distal opening 201. In the longitudinal direction of the catheter 1, the distal end of the gap 400 is referred to as the "gap distal end 401," and the proximal end of the gap 400 is referred to as the "gap proximal end 402." In the example of Fig. 10 , the gap distal end 401 is located away from the distal end of the sensor tube 10 toward the proximal end and is located distal to the distal end 201a of the distal opening 201. The gap proximal end 402 is located proximal to the proximal end 201b of the distal opening 201. The gap 400 is formed by the RX tube 30 and the sensor tube 10 being spaced apart from each other between the gap distal end 401 and the gap proximal end 402.

[0064] The length L400 of the gap 400 is the length between the gap distal end 401 and the gap proximal end 402. The length L400 of the gap 400 can be set arbitrarily, but is preferably longer than the length of the distal opening 201 (the length between the distal end 201a and the proximal end 201b). The width Φ400 of the gap 400 is the length between the outer circumferential surface of the sensor tube 10 facing the gap 400 and the outer circumferential surface of the RX tube 30 facing the gap 400. The width Φ400 is the length of the portion where the sensor tube 10 and the RX tube 30 are furthest apart. The width Φ400 of the gap 400 can be set arbitrarily. For example, the width Φ400 of the gap 400 can be the same as the outer diameter of the distal end of the OTW tube 20 or close to the outer diameter of the distal end of the OTW tube 20. In other words, the width Φ400 of the gap 400 can be the same as the outer diameter of the portion of the OTW tube 20 where the distal opening 201 is provided, or can be close to the outer diameter of the portion of the OTW tube 20 where the distal opening 201 is provided. On the other hand, the width Φ400 of the gap 400 is preferably the same as the inner diameter of the distal end of the OTW tube 20, or close to the inner diameter of the distal end of the OTW tube 20. In other words, the width Φ400 of the gap 400 is preferably the same as the inner diameter of the portion of the OTW tube 20 where the distal opening 201 is provided, or close to the inner diameter of the portion of the OTW tube 20 where the distal opening 201 is provided. Furthermore, the width Φ400 of the gap 400 may be smaller than the outer diameter of the treatment device 300 (see FIGS. 13 and 14 ) protruding from the OTW lumen 20L. The treatment device 300 often has an outer diameter close to the inner diameter of the OTW tube 20. Therefore, for example, the width Φ400 of the gap 400 may be set to (inner diameter of the tip of the OTW tube 20)×(½)<width Φ400<(inner diameter of the tip of the OTW tube 20)×(½ / 2). The sensor tube 10 and the RX tube 30 are formed of a resin material that can be elastically deformed relatively easily.Therefore, for example, even if the width Φ400 of the gap 400 is smaller than the outer diameter of the treatment device 300 protruding from the OTW lumen 20L, when the surgeon pushes the treatment device 300 into the gap 400 from the proximal end side of the OTW lumen 20L, the gap 400 widens due to elastic deformation of the sensor tube 10 and the RX tube 30. As a result, the surgeon can push the treatment device 300 into the gap 400.

[0065] Figure 11 is a cross-sectional view of the catheter 1 taken along line F-F in Figure 10. The F-F cross-section shown in Figure 11 shows a cross-section of the catheter 1 in a portion where the OTW tube 20 is not present. Figure 12 is a cross-sectional view of the catheter 1 taken along line G-G in Figure 10. The G-G cross-section shown in Figure 12 shows a cross-section of the catheter 1 at the distal end of the OTW tube 20. In Figure 12, of the two common circumferential tangents of the sensor tube 10 and the RX tube 30, the common circumferential tangent EC closer to the OTW tube 20 is shown by a two-dot chain line. The common circumferential tangent EC corresponds to the "first common circumferential tangent."

[0066] 12 , a portion of the distal end of the OTW tube 20 (second tube) is inserted into the gap 400. Here, the state in which "a portion of the distal end of the OTW tube 20 is inserted into the gap 400" will be described. A cross section of the catheter 1 at the position of a portion of the distal end of the OTW tube 20, i.e., a cross section of the catheter 1 at a position where the gap 400 has a width Φ400, is defined as a first cross section. A cross section of the catheter 1 at a position proximal to the gap 400 where the gap 400 is not formed, i.e., a cross section of the catheter 1 at a position proximal to the gap 400 where the sensor tube 10 and the RX tube 30 are in contact is defined as a second cross section. "A portion of the distal end of the OTW tube 20 enters the gap 400" means that the OTW tube 20 in the first transverse cross section is located closer to the sensor tube 10 and the RX tube 30 than the OTW tube 20 in the second transverse cross section, i.e., it enters the sensor tube 10 and the RX tube 30. For example, this means that the position of the OTW tube 20 in the transverse cross section taken along line G-G in Fig. 12 is located closer to the sensor tube 10 and the RX tube 30 than the position of the OTW tube 20 in the transverse cross section taken along line B-B in Fig. 4. In other words, in the longitudinal direction of the catheter 1, the OTW tube 20 is inclined in the direction toward the gap 400 from a position closer to the proximal end than the gap 400, where the sensor tube 10 and the RX tube 30 are in contact, toward a position where the gap 400 has a width Φ400. 12 , the outer portion of the thick-walled portion of the OTW tube 20 on the sensor tube 10 (first tube) side and the outer portion of the thick-walled portion of the sensor tube 10 come into contact and are deformed as shown. The outer portion of the thick-walled portion of the OTW tube 20 on the RX tube 30 (third tube) side and the outer portion of the thick-walled portion of the RX tube 30 come into contact and are deformed as shown. As shown, because only the thick-walled portions of the tubes 10, 20, and 30 are deformed, the inner diameters of the lumens 10L, 20L, and 30L can be maintained.

[0067] Hereinafter, the portion of the tip of the OTW tube 20 that is located inside the common circumferential tangent EC of the sensor tube 10 and the RX tube 30 (i.e., on the side of the sensor tube 10 and the RX tube 30) will also be referred to as the clamped portion 29. The length of the outer edge of the clamped portion 29 in the G-G cross section is at least half and at most two-half the length of the outer edge of the OTW tube 20. Note that in order to allow the tip to fit into the gap 400, the tip of the OTW tube 20 is inclined toward the sensor tube 10 and the RX tube 30 (+Z-axis direction in FIG. 10 ) from the base end toward the tip.

[0068] In this embodiment, the distal tube 11 (first tube) of the sensor tube 10 is made of a first material. The distal tube 21 (second tube) of the OTW tube 20 is made of a third material. The RX tube 30 (third tube) is made of a second material. In this case, the first material and the second material have different acoustic impedances. The first material and the third material have different acoustic impedances. The second material and the third material have different acoustic impedances.

[0069] The gap 400 in the catheter 1 can be created as follows. First, the operator prepares the sensor tube 10, the OTW tube 20, the RX tube 30, and a mandrel. The mandrel has an outer diameter that is the same as or slightly smaller than the diameter of the OTW lumen 20L. The operator inserts the mandrel into the OTW tube 20, leaving a portion of the distal end of the mandrel protruding from the distal opening 201. The operator bundles and grasps the sensor tube 10, the RX tube 30, and the OTW tube 20 with the mandrel inserted therein, and then passes the mandrel protruding from the distal opening 201 between the sensor tube 10 and the RX tube 30. In this state, the operator joins the three tubes 10, 20, and 30.

[0070] FIG. 13 is a diagram showing how the treatment device 300 is oriented in a first direction D1. FIG. 14 is a diagram showing how the treatment device 300 is oriented in a second direction D2. FIGS. 13 and 14 show cross-sectional views of the catheter 1 taken along line G-G in FIG. 10. Here, the first direction D1 refers to a direction from the center of the OTW tube 20 (second tube) toward the outside of the catheter 1, toward the side opposite the sensor tube 10 (first tube) and the RX tube 30 (third tube). In other words, in FIG. 13, the first direction D1 refers to a direction from the common external tangent EC toward the side where the sensor tube 10 and the RX tube 30 are not disposed. The second direction D2 refers to a direction from the center of the OTW tube 20 toward the outside of the catheter 1, toward the side of the sensor tube 10 and the RX tube 30. In other words, the second direction D2 means a direction from the common external tangent EC in FIG. 14 toward the side where the sensor tube 10 and the RX tube 30 are arranged.

[0071] As shown in Fig. 13 , when the treatment device 300 is caused to protrude from the distal end opening 201 (first distal end opening) (step a5), if the target site of treatment is in the first direction D1, the surgeon directly directs the distal end of the treatment device 300 toward the first direction D1. Here, as described in Fig. 1 , the distal end opening 201 has an elliptical shape in which the distal end of the OTW tube 20 is obliquely cut, and the distal end opening 201 faces the first direction D1. This allows the surgeon to smoothly direct the distal end of the treatment device 300 toward the first direction D1. Furthermore, because the distal end opening 201 has an elliptical shape, when the distal end of the treatment device 300 is directed toward the first direction D1, the distal end of the treatment device 300 protrudes from a position close to the proximal end 201b of the distal end opening 201 (i.e., the proximal end of the second marker 42). Therefore, the surgeon can easily understand that the tip of the treatment device 300 is facing in the first direction D1 based on the positional relationship between the tip of the treatment device 300 and the second marker 42 in the image displayed on the console terminal.

[0072] As shown in FIG. 14 , when the treatment device 300 is protruded from the distal end opening 201 (first distal end opening) (step a5), if the target site of treatment is in the second direction D2, the surgeon directs the distal end of the treatment device 300 through the gap 400 toward the second direction D2. Here, as described in FIG. 12 , a portion of the distal end of the OTW tube 20 is inserted into the gap 400. Therefore, the distal end opening 201 has a recessed portion at the position of the clamped portion 29 toward the sensor tube 10 and the RX tube 30 (in other words, toward the second direction D2). Therefore, the surgeon can push the distal end of the treatment device 300 along the recessed portion of the OTW tube at the position of the clamped portion 29. As a result, the surgeon can smoothly pass the distal end of the treatment device 300 through the gap 400 and direct it toward the second direction D2. Furthermore, because the distal opening 201 has an elliptical shape, when the distal end of the treatment device 300 is directed in the second direction D2, the distal end of the treatment device 300 protrudes from a position close to the distal end 201a of the distal opening 201 (i.e., the distal end of the second marker 42). Therefore, the surgeon can easily recognize that the distal end of the treatment device 300 is directed in the second direction D2 based on the positional relationship between the distal end of the treatment device 300 and the second marker 42 in the image displayed on the console terminal.

[0073] FIG. 15 shows the catheter 1 and the combined device in a first procedure. The first procedure is a procedure in which the false lumen 501 approaches the true lumen 502 after passing through the CTO 509. The surgeon inserts the workhorse wire 200 into the catheter 1, as in steps a1 and a2 described above. In step a3, the surgeon advances the catheter 1 through the false lumen 501 until the distal end of the catheter 1 passes through the CTO 509. In step a4, the surgeon confirms the position of the true lumen 502 using the probe 72 of the sensor 70. In step a5, the surgeon inserts the treatment device 300 into the catheter 1 and causes the distal end of the treatment device 300 to protrude from the distal opening 201. In step a6, the surgeon uses the treatment device 300 to penetrate the intima of the blood vessel 500 and perform re-entry from the false lumen 501 to the true lumen 502. For ease of explanation, in Fig. 15, the orientation of the catheter 1 inserted into the blood vessel 500 in its circumferential direction is the same as in Fig. 1. However, the orientation of the catheter 1 during the procedure is not limited to the orientation shown in Fig. 15 and may be determined arbitrarily by the surgeon. For example, the orientation of the catheter 1 during the procedure may be rotated 90 degrees clockwise or counterclockwise in the circumferential direction of the catheter 1 from the orientation shown in Fig. 15.

[0074] FIG. 16 shows the catheter 1 and the combined device in a second procedure. The second procedure is a procedure for penetrating the CTO 509 present at the entrance of a branched blood vessel that branches into a first branch 510 and a second branch 520. The surgeon inserts the work horse wire 200 into the catheter 1 as in steps a1 and a2 described above. In step a3, the surgeon advances the catheter 1 through the blood vessel 500 until the distal end of the catheter 1 is positioned proximal to the CTO 509 formed in the first branch 510. In step a4, the surgeon confirms the positions of the first branch 510 and the CTO 509 using the probe 72 of the sensor 70. In step a5, the surgeon inserts the treatment device 300 into the catheter 1 and causes the distal end of the treatment device 300 to protrude from the distal opening 201. In step a6, the surgeon uses the treatment device 300 to penetrate the CTO 509 and open the first branch 510. 16, as in Fig. 15, the circumferential orientation of the catheter 1 inserted into the blood vessel 500 is the same as in Fig. 1. However, the orientation of the catheter 1 in the procedure is not limited to the orientation shown in Fig. 16 and may be determined arbitrarily by the surgeon.

[0075] FIG. 17 shows the catheter 1 and the combined device in a third procedure. The third procedure is a procedure for penetrating the CTO 509 from the proximal side of the blood vessel 500. The surgeon inserts the workpiece wire 200 into the catheter 1 as in steps a1 and a2 described above. In step a3, the surgeon pushes the catheter 1 until the tip of the catheter 1 is inside the CTO 509 blocking the blood vessel 500 and at a position where the shape of the CTO 509 makes it easy to penetrate the CTO 509 (a position where there is a depression in the CTO 509). At this time, the gap 400 is compressed by external pressure applied from the CTO 509, and as shown in the figure, the width of the gap 400 changes slightly, making it easier to push the tip of the catheter 1 into the CTO 509. In step a4, the surgeon uses the probe 72 of the sensor 70 to confirm the position of the true lumen 502 in the depression in the CTO 509. In step a5, the surgeon inserts the treatment device 300 into the catheter 1 and causes the distal end of the treatment device 300 to protrude from the distal opening 201. In step a6, the surgeon uses the treatment device 300 to penetrate the CTO 509 and causes the distal end of the treatment device 300 to reach the true lumen 502. In Fig. 17 , as in Fig. 15 , the circumferential orientation of the catheter 1 inserted into the blood vessel 500 is the same as in Fig. 1 . However, the orientation of the catheter 1 in the procedure is not limited to the orientation shown in Fig. 17 and may be determined arbitrarily by the surgeon.

[0076] In step a5 in Figures 15 to 17 , regardless of where the target site of treatment (the intima between the false lumen 501 and the true lumen 502) is located circumferentially around the catheter 1, the surgeon can smoothly orient the distal end of the treatment device 300 in the intended direction either directly through the distal opening 201 ( Figure 13 ) or through the gap 400 ( Figure 14 ). Furthermore, in Figures 15 to 17 , steps a4 and onward are performed with the work horse wire 200 inserted in the RX lumen 30L of the catheter 1, allowing the work horse wire 200 to function as a landmark for determining the orientation of the catheter 1. Furthermore, in Figures 15 to 17 , the treatment device 300 enters the biological tissue at the position of the observation plane SS of the sensor 70, as described in step a6, thereby improving the safety of the procedure.

[0077] As described above, according to the catheter 1 (medical device) of the first embodiment, a gap 400 is formed between the sensor tube 10 (first tube) and the RX tube 30 (third tube) at the position of the distal end opening 201 (first distal end opening). Therefore, when the treatment device 300 is inserted into the OTW lumen 20L (second lumen) and the distal end of the treatment device 300 protrudes from the distal end opening 201 ( FIGS. 15 to 17 ), even if the target site of treatment is located on the side of the sensor tube 10 and the RX tube 30, the treatment device 300 can reach the target site by passing through the gap 400 ( FIG. 14 ). As a result, a medical device 1 can be provided in which the treatment device 300 in the lumen can be easily directed toward the target site of treatment.

[0078] Furthermore, according to the catheter 1 (medical device) of the first embodiment, the distal end of the OTW tube 20 (second tube) is inclined in a direction toward the gap 400 as it approaches the distal end. Therefore, the distal end of the treatment device 300 protruding from the distal end opening 201 (first distal end opening) can be passed through the gap 400 more smoothly.

[0079] Furthermore, according to the catheter 1 (medical device) of the first embodiment, a portion of the distal end of the OTW tube 20 (second tube) fits into the gap 400 between the sensor tube 10 and the RX tube 30 ( FIG. 12 ). Therefore, the distal end of the OTW tube 20 is configured to be inclined toward the sensor tube 10 and the RX tube 30 as it approaches the distal end. As a result, the distal end of the treatment device 300 protruding from the distal end opening 201 (first distal end opening) can be passed through the gap 400 more smoothly ( FIG. 14 ).

[0080] Furthermore, according to the catheter 1 (medical device) of the first embodiment, the length of the outer edge of the clamped portion 29 is at least half and at most two-half the length of the outer edge of the distal end of the OTW tube 20 (second tube). This allows the distal end of the treatment device 300 protruding from the distal end opening 201 (first distal end opening) to pass through the gap 400 more smoothly.

[0081] Furthermore, according to the catheter 1 (medical device) of the first embodiment, the width Φ400 of the gap 400 is larger than the inner diameter × (½) of the tip of the OTW tube 20 and smaller than the inner diameter × (½) of the tip of the OTW tube 20. Therefore, even a treatment device 300 having an outer diameter close to the inner diameter of the OTW tube 20 (second tube) can be used.

[0082] Furthermore, according to the catheter 1 (medical device) of the first embodiment, when the distal end of the treatment device 300 is protruded from the distal end opening 201 (first distal end opening), even if the target site of treatment is located on the opposite side of the sensor tube 10 and the RX tube 30, the elliptical shape of the distal end opening 201 makes it easy to point the distal end of the treatment device 300 toward the target site ( FIG. 13 ). As a result, the usability of the catheter 1 can be further improved.

[0083] Furthermore, according to the catheter 1 (medical device) of the first embodiment, a portion of the outer circumferential surface of the sensor tube 10 (first tube) and a portion of the outer circumferential surface of the RX tube 30 (third tube) are in contact with each other distally of the gap 400 (e.g., in the A-A cross section), allowing the distal end of the catheter 1 to be narrowed. Furthermore, the gap distal end 401 is located proximally of the distal end of the sensor tube 10 and distally of the distal end 201a of the distal opening 201 (first distal opening), and the gap proximal end 402 is located proximally of the proximal end 201b of the distal opening 201. This allows the length L400 of the gap 400 to be sufficiently maintained, making it easier to pass the distal end of the treatment device 300 through the gap 400. As a result, the usability of the catheter 1 can be further improved.

[0084] Furthermore, according to the catheter 1 (medical device) of the first embodiment, the tip of the RX lumen 30L (third lumen) is located closer to the tip of the sensor lumen 10L (first lumen), thereby enabling a thinner diameter for the tip portion of the catheter 1. Also, the tip of the RX lumen 30L is provided with a tip opening 301 (second tip opening) that connects the RX lumen 30L to the outside, allowing the RX lumen 30L to be used as a lumen for a work horse wire.

[0085] Furthermore, according to the catheter 1 (medical device) of the first embodiment, the first material forming the sensor tube 10 (first tube) and the second material forming the RX tube 30 (third tube) 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. Also, the first material forming the sensor tube 10 and the third material forming the OTW tube 20 (second tube) 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. Furthermore, the second material forming the RX tube 30 and the third material forming the OTW tube 20 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.

[0086] 18 is an enlarged view of a portion of the distal end of a catheter 1A according to a second embodiment. The catheter 1A according to the second embodiment has the same configuration as that described in the first embodiment, except that it includes a gap 400A instead of the gap 400, a second marker 42A instead of the second marker 42, and a third marker 43.

[0087] 18 , the gap tip 401A of the gap 400A is located away from the distal end of the sensor tube 10 toward the proximal end and further distal than the distal end 201a of the distal opening 201. The gap tip 401A is also located at the position where the second marker 42A is provided (specifically, the center of the second marker 42A). The gap base end 402A of the gap 400A is located further proximal than the proximal end 201b of the distal opening 201. In the second embodiment, the length L400A and width Φ400A of the gap 400A can also be determined arbitrarily.

[0088] The second marker 42A and the third marker 43 are annular radiopaque members. The second marker 42A is arranged so that the center of the second marker 42A and the gap tip 401A are aligned in the longitudinal direction of the catheter 1A. That is, the second marker 42A is a mark indicating the position of the gap tip 401A. The third marker 43 is arranged so that the center of the third marker 43 and the center of the tip opening 201 are aligned in the longitudinal direction of the catheter 1A. That is, the third marker 43 is a mark indicating the position of the tip opening 201. As with the first embodiment, it is more preferable that the second marker 42A and the third marker 43 be made of metal.

[0089] As described above, the configuration of the catheter 1A can be modified in various ways, and the gap 400A may be provided with a second marker 42A indicating the position of the gap 400A. Like the first embodiment, the catheter 1A of the second embodiment can be used in the first procedure ( FIG. 15 ), the second procedure ( FIG. 16 ), and the third procedure ( FIG. 17 ). In the catheter 1A, the distal end opening 201 is located closer to the proximal end of the catheter 1A than in the configuration of the first embodiment, allowing the distal end of the catheter 1A to be made thinner. Therefore, the catheter 1A is particularly suitable for the third procedure in which the distal end is advanced into the CTO 509. The catheter 1A of the second embodiment described above can also achieve the same effects as the first embodiment. Furthermore, with the catheter 1A of the second embodiment, the surgeon can easily grasp the position of the gap tip 401A by checking the image displayed on the console terminal.

[0090] <Third embodiment> Figure 19 is an enlarged view of a portion of the distal end side of a catheter 1B of a third embodiment. Figure 20 is a transverse cross-sectional view of the catheter 1B taken along line H-H in Figure 19. A catheter 1A of the third embodiment has the same configuration as that described in the first embodiment, except that it includes an OTW tube 20B instead of the OTW tube 20, a gap 400B instead of the gap 400, and a fourth marker 44.

[0091] 19 , the OTW tube 20B further includes a side opening 203 in addition to the configuration described in the first embodiment. The side opening 203 is provided in the side wall of the OTW tube 20B at a position farther proximally than the distal opening 201, and is a through-hole that connects the OTW lumen 20L to the outside. A distal end 203a of the side opening 203 is located proximally than the proximal end 201b of the distal opening 201. As shown in FIG. 20 , the side opening 203 is provided in the side wall of the OTW tube 20B at a position facing the gap 400B.

[0092] As shown in FIG. 19 , the gap tip 401B of the gap 400B is located at the same position as the tip 201a of the tip opening 201. The gap base 402B of the gap 400B is located closer to the base end than the base end 203b of the side opening 203. In the third embodiment, the length L400B and width Φ400B of the gap 400B can be determined arbitrarily. The fourth marker 44 is a radiopaque annular member. The fourth marker 44 is positioned such that the center of the fourth marker 44 and the center of the side opening 203 are located at the same position in the longitudinal direction of the catheter 1B. In other words, the fourth marker 44 is a mark indicating the position of the side opening 203. As in the first embodiment, it is preferable that the fourth marker 44 be made of metal.

[0093] As described above, the configuration of the catheter 1B can be modified in various ways, and the OTW tube 20B may further be formed with a side opening 203 for allowing the treatment device 300 to project into the gap 400B. Like the first embodiment, the catheter 1B of the third embodiment can also be used in the first procedure ( FIG. 15 ), second procedure ( FIG. 16 ), and third procedure ( FIG. 17 ). The catheter 1B of the third embodiment as described above can also achieve the same effects as the first embodiment described above.

[0094] Furthermore, according to the catheter 1B of the third embodiment, by using the side opening 203 facing the gap 400B, it is even easier to pass the distal end of the treatment device 300 through the gap 400B ( FIG. 20 ). The distal end opening 201 and the side opening 203 are located apart from each other in the longitudinal direction of the catheter 1B, and a second marker 42 is provided at the position of the distal end opening 201, and a fourth marker 44 is provided at the position of the side opening 203. Therefore, by checking the positional relationship between the treatment device 300, the second marker 42, and the fourth marker 44 on the image displayed on the console terminal, the surgeon can easily determine whether the treatment device 300 protrudes from the distal end opening 201 in the first direction D1 or the treatment device 300 protrudes from the side opening 203 in the second direction D2. Of course, the surgeon can also protrude the distal end of the treatment device 300 from the distal end opening 201 in the catheter 1B. As described above, according to the catheter 1B of the third embodiment, the OTW tube 20B (second tube) further has a side opening 203 in the side wall at a position away from the distal end opening 201 (first distal end opening) toward the proximal end, allowing the treatment device 300 to protrude from the side opening as well. The side opening 203 is also provided in a portion of the side wall of the OTW tube 20B that faces the gap 400B. Therefore, the treatment device 300 protruding from the side opening 203 can be smoothly passed through the gap 400B. As a result, the usability of the catheter 1B can be further improved.

[0095] <Fourth embodiment> Figure 21 is a transverse cross-sectional view of a catheter 1C of a fourth embodiment. Figure 21 corresponds to the G-G transverse cross-section of Figure 10. The catheter 1C of the fourth embodiment has the same configuration as that described in the first embodiment, except that it includes a sensor tube 10C instead of the sensor tube 10, an OTW tube 20C instead of the OTW tube 20, and an RX tube 30C instead of the RX tube 30.

[0096] The tip of the OTW tube 20C does not enter the gap 400. In other words, the position of the OTW tube 20C in the first transverse cross section is the same as the position of the OTW tube 20C in the second transverse cross section. The tip of the OTW tube 20C is not inclined toward the gap 400 and is parallel to the sensor tube 10C and the RX tube 30C. In other words, the sensor tube 10C, the OTW tube 20C, and the RX tube 30C are simply in contact with each other at their outer circumferential surfaces, and there are no deformed portions of the thick-walled portions around the gap 400. Note that in this embodiment as well, the tip of the OTW tube 20C is provided with a clamped portion 29 located inside the common external tangent line EC of the sensor tube 10C and the RX tube 30C.

[0097] As described above, the configuration of the catheter 1C can be modified in various ways, and a configuration may be adopted in which the distal end of the OTW tube 20C does not enter the gap 400. Like the first embodiment, the catheter 1C of the fourth embodiment can also be used in the first procedure ( FIG. 15 ), second procedure ( FIG. 16 ), and third procedure ( FIG. 17 ). The catheter 1C of the fourth embodiment as described above can also achieve the same effects as the first embodiment described above.

[0098] 22 is an enlarged view of a portion of the distal end side of a catheter 1D of a fifth embodiment. The catheter 1D of the fifth embodiment has the same configuration as that described in the first embodiment, except that it includes a sensor tube 10D instead of the sensor tube 10 and a gap 400D instead of the gap 400.

[0099] As shown in FIG. 22 , a portion of the sensor tube 10D is curved in a direction away from the RX tube 30 (+Y-axis direction). Similarly to the first embodiment, a portion of the RX tube 30 is curved in a direction away from the sensor tube 10D (-Y-axis direction). In this manner, in the catheter 1D, the sensor tube 10D and the RX tube 30 are curved away from each other and spaced apart, thereby forming a gap 400D. The gap tip 401D and the gap base 402D of the gap 400D are located in the same positions as in the first embodiment. In the fifth embodiment, the length L400D and width Φ400D of the gap 400D can also be determined arbitrarily.

[0100] As described above, the configuration of the catheter 1D can be modified in various ways. The gap 400D may be formed by bending both the sensor tube 10D and the RX tube 30. Alternatively, the gap 400D may be formed by bending only the sensor tube 10D while leaving the RX tube 30 straight and uncurved. Like the first embodiment, the catheter 1D of the fifth embodiment can be used in the first procedure ( FIG. 15 ), the second procedure ( FIG. 16 ), and the third procedure ( FIG. 17 ). The catheter 1D of the fifth embodiment can also achieve the same effects as the first embodiment. Furthermore, in the catheter 1D of the fifth embodiment, the width Φ400D of the gap 400D can be made larger than in the configuration of the first embodiment. As a result, the catheter 1D makes it even easier to pass the distal end of the treatment device 300 through the gap 400D.

[0101] <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.

[0102] [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.

[0103] For example, the sensor tube 10 may be formed from a single tube without having the distal tube 11 and the proximal tube 12. Similarly, the OTW tube 20 may be formed from 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, by providing a through-hole that penetrates the shaft in the Z-axis direction in a thick portion of the shaft between the sensor lumen 10L and the RX lumen 30L at the position of the distal opening 201, the through-hole can function as a gap, thereby achieving the same effect as in the first embodiment.

[0104] For example, the catheter 1 may further be provided with a covering portion for suppressing the expansion of the gaps 400, 400A, 400B, and 400D during use. The covering portion can be configured to include at least one of a distal covering portion and a proximal covering portion. The distal covering portion is a layer that covers the outer surfaces of the sensor tube 10 and the RX tube 30 distally of the distal end of the gap. The proximal covering portion is a layer that covers the outer surfaces of the sensor tube 10, the OTW tube 20, and the RX tube 30 proximally of the proximal end of the gap. The covering portion can be formed using a coating agent or an adhesive. Forming the covering portion using a coating agent can suppress the expansion of the gap 400 while maintaining flexibility.

[0105] For example, the distal opening 201 (first distal opening) of the OTW lumen 20L may be circular, with the distal end of the OTW tube 20 cut vertically. Similarly, the proximal opening 302 of the RX lumen 30L may be circular, with the proximal end of the RX tube 30 cut vertically. For example, the distal opening 201 of the OTW lumen 20L may be located more distally than the distal opening 301 of the RX lumen 30L, and the distal opening 301 of the RX lumen 30L may be located more proximal than the acoustic window AW.

[0106] 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 tubes 10, 20, and 30 can be distinguished from one another in the image acquired by the sensor 70 by making the thicknesses of the tubes 10, 20, and 30 different from one another.

[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. 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. 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, the second marker 42, the third marker 43, and the fourth marker 44 may be omitted. Furthermore, their arrangement and shape 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 at a position distant from the proximal end of the distal tip 40. For example, at least one of the first to fourth markers 41, 42, 43, and 44 may be positioned on a tube (such as the sensor tube 10 or the OTW tube 20) 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 to fourth markers 41, 42, 43, and 44 may have a shape other than a ring shape (for example, a ring shape cut at an arbitrary angle, a wire shape, or a coil shape made by winding a wire in a spiral shape).

[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 tubular member 64, the inner tubular member 67, 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, the outer tubular member 64, and the inner tubular 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 from a transparent material, and the inner cylindrical member 67 may be provided with a mechanism that assists in adjusting at least one of the front-to-back position of the sensor 70 and the circumferential orientation of the sensor 70 (for example, a scale or stopper provided at predetermined lengths in the longitudinal direction, or a scale or stopper provided at predetermined angles in the circumferential direction).

[0110] [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 appropriately combined. For example, either the catheter 1A or 1B described in the second or third embodiment may be provided with the OTW tube 20C described in the fourth embodiment, or the sensor tube 10D described in the fifth embodiment.

[0111] 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.

[0112] DESCRIPTION OF SYMBOLS 1, 1A to 1D...Catheter (medical device) 10, 10D...Sensor tube (first tube) 11...Distal tube 12...Proximal tube 20, 20B, 20C...OTW tube (second tube) 21...Distal tube 22...Proximal tube 25...Connector 29...Clasped portion 30...RX tube (third tube) 40...Distal tip 41...First marker 42, 42A...Second marker 43...Third marker 44...Fourth marker 50...First outer tube 60...Branch connector 61...First reinforcing member 62...Second reinforcing member 63...Third reinforcing member 64...Outer tubular member 65...Connector 66...Fluid supply portion 67...Inner tubular member 70...Sensor 71...Main body 72...Probe 75...Connection terminal 80...Second outer tube 90... Heat shrink tube 101... Distal opening 102... Proximal opening 200... Work hose wire 201... Distal opening 202... Proximal opening 203... Side opening 300... Treatment device 301... Distal opening 302... Proximal opening 400, 400A, 400B, 400D... Gaps 401, 401A, 401B, 401D... Gap tips 402, 402A, 402B, 402D... Gap base ends

Claims

1. A medical device comprising: a first tube having a first lumen; a second tube disposed alongside the first tube and having a second lumen; and a third tube disposed alongside the first and second tubes and having a third lumen, wherein a distal end of the second tube is disposed closer to a proximal end than a distal end of the first tube and closer to the proximal end than a distal end of the third tube, a first distal opening communicating the second lumen with the outside is formed at the distal end of the second tube, and a gap is formed between the first tube and the third tube by the first tube and the third tube being spaced apart from each other at a position of the first distal opening.

2. The medical device according to claim 1, wherein a distal end portion of the second tube is inclined in a direction toward the gap as it extends toward the distal end.

3. The medical device according to claim 1 or 2, wherein a part of the distal end portion of the second tube extends into the gap.

4. The medical device according to claim 3, wherein, in a cross-section at a position where the gap of the medical device is formed, when a common circumferential line closer to the second tube among common circumferential lines of the first tube and the third tube is defined as a first common circumferential line, a length of an outer edge of a clamped portion, which is a portion of the distal end portion of the second tube located inside the first common circumferential line, is 1 / 2 or more and 2 / 2 or less of a length of an outer edge of the distal end portion of the second tube.

5. The medical device according to any one of claims 1 to 4, wherein a width of the gap is greater than an inner diameter of the distal end of the second tube × (1 / 2) and less than an inner diameter of the distal end of the second tube × (2 / 2).

6. The medical device according to any one of claims 1 to 5, wherein the first distal opening has an elliptical shape formed by obliquely cutting the distal end portion of the second tube.

7. The medical device according to claim 6, wherein, on the tip side of the gap, a part of the outer peripheral surface of the first tube and a part of the outer peripheral surface of the third tube are in contact with each other; the tip of the gap is located on the proximal side of the tip of the first tube and on the tip side of the tip of the first tip opening; and the base end of the gap is located on the proximal side of the base end of the first tip opening.

8. The medical device according to any one of claims 1 to 7, wherein the tip of the third lumen is located on the tip side of the tip of the first lumen; and a second tip opening for communicating the third lumen with the outside is provided at the tip of the third lumen.

9. The medical device according to any one of claims 1 to 8, wherein a side opening for communicating the second lumen with the outside is further provided in the side wall of the second tube at a position away from the first tip opening toward the proximal side.

10. The medical device according to claim 9, wherein the side opening is provided in a portion of the side wall of the second tube facing the gap.

11. The medical device according to any one of claims 1 to 10, wherein the first tube is formed of a first material; the third tube is formed of a second material; and the first material and the second material have different acoustic impedances.

12. The medical device according to claim 11, wherein the second tube is formed of a third material; and the first material and the third material have different acoustic impedances.

13. The medical device according to claim 12, wherein the second material and the third material have different acoustic impedances.