Medical device

Abstract

This medical device is provided with: a first tube whose melting point is a first temperature; a second tube whose melting point is a second temperature different from the first temperature and whose tip is located closer to the base end side than the base end of the first tube; and a connection member whose melting point is a third temperature, which is higher than the lower temperature from among the first temperature and the second temperature, the connection member being in contact with the first tube and the second tube and indirectly connecting the first tube and the second tube in a state in which the first tube and the second tube are separated from each other.

Description

medical devices

[0001] The present invention relates to medical devices.

[0002] To improve safety and operability, catheters generally have a flexible distal end and a highly rigid proximal end. For example, Patent Document 1 discloses a method for manufacturing a catheter tube formed by axially joining a distal tube having a relatively low rigidity and a proximal tube having a relatively high rigidity. In the method described in Patent Document 1, the distal end of the proximal tube is inserted into the proximal end of the distal tube, and the inner surface of the proximal end of the distal tube and the outer surface of the distal end of the proximal tube are joined.

[0003] JP 2013-005976 A

[0004] However, the technology described in Patent Document 1 has a structure in which the distal end of the proximal tube is inserted inside the distal tube, which creates a step in the catheter lumen. In this case, depending on the type of other device (e.g., a workhorse wire, a treatment device, a sensor, etc.) inserted into the catheter or the shaping applied to the catheter, the other device may become caught on the step in the catheter lumen. There was a problem that other devices getting caught in the catheter lumen not only interferes with the procedure but also leads to damage to the catheter, which is undesirable.

[0005] This problem also occurs when an internal burr (a step or protrusion) is formed at the connection between two tubes, even when the tube does not have a structure in which one tube is inserted inside the other. This problem is not limited to PCI procedures, but is common to all medical devices used in percutaneous procedures. Furthermore, this problem is not limited to the vascular system, but is common to all medical devices inserted into various organs within the human body, such as the lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and aims to suppress the occurrence of internal burrs at the connection portion of two axially arranged tubes.

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

[0008] (1) According to one aspect of the present invention, there is provided a medical device comprising: a first tube having a melting point at a first temperature; a second tube having a melting point at a second temperature different from the first temperature and having a distal end located proximal to a proximal end of the first tube; and a connecting member having a melting point at a third temperature higher than the lower of the first and second temperatures, the connecting member being in contact with the first tube and the second tube and connecting the first tube and the second tube while separating them.

[0009] This configuration can prevent internal burrs from being generated on the medical device, thereby preventing other devices (e.g., workhorse wires, treatment devices, sensors, etc.) inserted into the medical device from getting caught in the lumen of the medical device during use, thereby preventing the medical device from being damaged or hindered during a procedure due to the catching.

[0010] (2) In the medical device of the above aspect, the distal end of the connecting member may be located distally of the proximal end of the first tube, and the proximal end of the connecting member may be located proximally of the distal end of the second tube. With this configuration, the distal end of the connecting member is located distally of the proximal end of the first tube, thereby increasing the contact area between the connecting member and the first tube. Furthermore, the proximal end of the connecting member is located proximal to the distal end of the second tube, thereby increasing the contact area between the connecting member and the second tube.

[0011] (3) In the medical device of the above aspect, the connecting member may be a heat-shrinkable tube.

[0012] (4) In the medical device of the above aspect, the axial distance L1 from the proximal end of the first tube to the distal end of the second tube may be shorter than the sum of the axial distance L2 from the distal end of the second tube to the proximal end of the connecting member and the axial distance L3 from the distal end of the connecting member to the proximal end of the first tube. This configuration can reduce the rigidity gap in the axial direction of the medical device.

[0013] (5) In the medical device of the above aspect, the axial distance L1 from the proximal end of the first tube to the distal end of the second tube may be shorter than at least one of the axial distance L2 from the distal end of the second tube to the proximal end of the connecting member and the axial distance L3 from the distal end of the connecting member to the proximal end of the first tube. This configuration can reduce the rigidity gap in the axial direction of the medical device.

[0014] (6) In the medical device of the above aspect, the connecting member may be made of fluororesin, and an axial distance L4 of an inner circumferential surface of the connecting member may be longer than an axial distance L1 from the base end of the first tube to the tip end of the second tube. This configuration can improve the slidability of other devices on the inner circumferential surface of the connecting member.

[0015] (7) In the medical device of the above aspect, the maximum inner diameter of the second tube may be larger than the maximum inner diameter of the first tube. With this configuration, the diameter of the lumen formed by the first tube, the second tube, and the connecting member can be adjusted to a size that conforms to the change in outer diameter of other general devices.

[0016] (8) In the medical device of the above aspect, the wall thickness of the second tube may be thicker than the wall thickness of the first tube. With this configuration, the proximal end side of the medical device can be made more rigid than the distal end side.

[0017] (9) In the medical device of the above aspect, a sensor for acquiring image information may be inserted into a lumen formed by the first tube, the second tube, and the connecting member. With this configuration, a procedure can be performed using image information (ultrasound images) acquired from the sensor.

[0018] 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.

[0019] 1 is an explanatory diagram illustrating the configuration of a catheter as a medical device; FIG. 1 is an explanatory diagram illustrating the configuration of a catheter as a medical device; FIG. 2 is a transverse cross-sectional view of a catheter; FIG. 3 is a diagram illustrating a method of using a catheter; FIG. 4 is a diagram illustrating a method of using a catheter; FIG. 5 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube; FIG. 6 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube of a comparative example; FIG. 7 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube of a second embodiment; FIG. 8 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube of a third embodiment; FIG. 9 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube of a fourth embodiment; FIG. 10 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube of a fifth embodiment; FIG. 11 is an explanatory diagram illustrating the configuration of a catheter of a sixth embodiment; FIG. 12 is an explanatory diagram illustrating the configuration of a catheter of a seventh embodiment.

[0020] First Embodiment FIGS. 1 and 2 are explanatory diagrams illustrating the configuration of a medical device 1. The medical device 1 of this embodiment is a catheter used to treat a lesion in a biological lumen, such as a CTO occurring in a blood vessel. Hereinafter, the medical device 1 will also be referred to as a "catheter 1." 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 covering portion 50, a branch connector 60, first to third reinforcing members 61 to 63, a tubular member 64, a connector 65, a connector 25, and a sensor 70. The sensor tube 10 is a medical tube. The sensor tube 10 is a medical device. The OTW tube 20 is a medical tube. The OTW tube 20 is a medical device.

[0021] 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.

[0022] For ease of explanation, in Figures 1 and 2, 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.

[0023] FIG. 3 is a cross-sectional view of the catheter 1. FIG. 3(A) shows a cross-section of the catheter 1 taken along line A-A in FIG. 1. FIG. 3(B) shows a cross-section of the catheter 1 taken along line B-B in FIG. 1. FIG. 3(C) shows a cross-section of the catheter 1 taken along line C-C in FIG. 1. FIG. 3(D) shows a cross-section of the catheter 1 taken along line D-D in FIG. 1. FIG. 3(E) shows a cross-section of the catheter 1 taken along line E-E in FIG. 1. FIG. 3(F) shows a cross-section of the catheter 1 taken along line F-F in FIG. 1. The configuration of the catheter 1 will be described below with reference to FIGS. 1 to 3.

[0024] 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.

[0025] The distal end of the sensor tube 10 is located at the same position as or slightly closer to the proximal end than the distal end of the RX tube 30 in the longitudinal direction of the catheter 1. A distal opening 101 is formed at the distal end of the sensor tube 10, connecting the distal end of the sensor lumen 10L to the outside. The distal opening 101 is a fluid outlet for maintaining a wet state inside the sensor lumen 10L. The proximal end of the sensor tube 10 is located closer to the proximal end than the proximal end of the OTW lumen 20L and the proximal end of the RX tube 30 in the longitudinal direction of the catheter 1. A first reinforcing member 61, a branch connector 60, a tubular member 64, and a connector 65 are attached to the proximal end of the sensor tube 10, from the distal end toward the proximal end. Details will be described later. A fluid supply unit 66 is attached to the connector 65, and a proximal opening 102 is formed in the fluid supply unit 66, connecting the proximal end of the sensor lumen 10L to the outside. The proximal opening 102 is a fluid supply port to the sensor lumen 10L.

[0026] 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 at any longitudinal location where the covering portion 50 is provided. In other words, the distal tube 11 and the proximal tube 12 each constitute a part of the sensor lumen 10L.

[0027] The OTW tube 20 is a cylindrical member (tubular body) having a long outer shape. The OTW tube 20 extends linearly along the longitudinal direction of the catheter 1, parallel to the sensor tube 10 and the RX tube 30, distal to the branch connector 60. An OTW lumen 20L (dashed line) for accommodating a therapeutic device (e.g., a plasma guidewire or a penetration guidewire) is formed inside the OTW tube 20. The OTW lumen 20L is a so-called over-the-wire (OTW) type lumen that does not have a proximal opening in the portion that is placed inside the biological lumen when the catheter 1 is in use.

[0028] The distal end of the OTW tube 20 is located closer to the proximal end than the distal end of the sensor tube 10 and the distal end of the RX tube 30 in the longitudinal direction of the catheter 1. A distal opening 201 that connects the distal end of the OTW lumen 20L to the outside is formed at the distal end of the OTW tube 20. The distal opening 201 is a device ejection port for ejecting a therapeutic device toward biological tissue. By cutting the distal end of the OTW tube 20 obliquely, the distal opening 201 faces in a direction intersecting the longitudinal direction of the catheter 1. This makes it easier for the therapeutic device to reach biological tissue present around the catheter 1 when the catheter 1 is in use. The proximal end of the OTW tube 20 is located closer to the distal end of the sensor tube 10 and closer to the proximal end of the RX tube 30 in the longitudinal direction of the catheter 1. On the proximal end side of the OTW tube 20, a first reinforcing member 61, a branch connector 60, a second reinforcing member 62, a third reinforcing member 63, and a connector 25 are attached, from the distal end side to the proximal end side. Details will be described later. The connector 25 has a proximal end opening 202 that connects the proximal end of the OTW lumen 20L to the outside. The proximal end opening 202 is a device insertion port for inserting a therapeutic device into the OTW lumen 20L.

[0029] 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 at any position in the longitudinal direction where the covering portion 50 is provided. In other words, the distal tube 21 and the proximal tube 22 each constitute a part of the OTW lumen 20L.

[0030] The RX tube 30 is a cylindrical member (tubular body) having an elongated outer shape. The RX tube 30 extends linearly along the longitudinal direction of the catheter 1, parallel to the sensor tube 10 and the OTW tube 20. An RX lumen 30L (dashed line) for accommodating a work hose wire is formed inside the RX tube 30.

[0031] The distal end of the RX tube 30 is located at the same position as or slightly distal to the distal end of the sensor tube 10 in the longitudinal direction of the catheter 1. A hollow distal tip 40 is joined to the distal portion of the RX tube 30. A distal opening 301 is formed at the distal end of the distal tip 40, connecting the distal end of the RX lumen 30L to the outside. The distal opening 301 is a wire insertion port for inserting the work horse wire into the RX lumen 30L. The proximal end of the RX tube 30 is located distal to the proximal end of the sensor tube 10 and the proximal end of the OTW tube 20 in the longitudinal direction of the catheter 1. A proximal end opening 302 is formed at the proximal end of the RX tube 30, connecting the proximal end of the RX lumen 30L to the outside. The proximal end opening 302 is a wire withdrawal port for withdrawing the work horse wire to the outside. By cutting the base end of the RX tube 30 obliquely, the base end opening 302 faces in a direction intersecting the longitudinal direction of the catheter 1. This makes it easier to pull out the work hose wire from the base end opening 302 when the catheter 1 is in use.

[0032] 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.

[0033] The first marker 41 and the second marker 42 are radiopaque, annular members. The first marker 41 is disposed on the outer peripheral surface of the RX tube 30 at a position adjacent to the base end of the distal tip 40 and is bonded to the outer peripheral surface of the RX tube 30. The second marker 42 is disposed on the outer peripheral surface of the RX tube 30 at a position adjacent to the distal end of the distal opening 201 of the OTW tube 20 and is bonded to the outer peripheral surface of the RX tube 30. The first marker 41 and the second marker 42 can be bonded, for example, by bonding resins together using thermal fusion or by bonding with an adhesive such as an epoxy adhesive. The first marker 41 and the second marker 42 may be colored so that they can be directly viewed by the surgeon. In this way, by placing the first marker 41 and the second marker 42 on the RX tube 30, it is possible to prevent the first marker 41 and the second marker 42 from interfering with sensing (acquisition of image information) by the sensor 70.

[0034] As shown in FIG. 3A, in the cross section taken along line A-A, only the distal tip 40 is present. As shown in FIG. 3B, in the cross section taken along line B-B, the outer peripheral surfaces of the sensor tube 10 (specifically, the distal tube 11) and the RX tube 30 are joined together. As shown in FIG. 3C, in the cross section taken along line C-C, the outer peripheral surfaces of the sensor tube 10 (specifically, the distal tube 11), the OTW tube 20 (specifically, the distal tube 21), and the RX tube 30 are joined together. As shown in FIG. 3D, in the cross section taken along line D-D, the outer peripheral surfaces of the sensor tube 10 (specifically, the distal tube 11), the OTW tube 20 (specifically, the distal tube 21), and the RX tube 30 are joined together. In addition, in the D-D cross section, the covering unit 50 covers the outward facing portions of the three tubes 10, 20, and 30 along the outer peripheries of the three tubes 10, 20, and 30, thereby fixing the three tubes 10, 20, and 30. As shown in FIG. 3(E) , in the cross section taken along line E-E, the outer peripheries of the sensor tube 10 (specifically, the distal tube 11), the OTW tube 20 (specifically, the proximal tube 22), and the RX tube 30 are joined together. In the E-E cross section as well, the covering unit 50 covers the outward facing portions of the three tubes 10, 20, and 30 along the outer peripheries of the three tubes 10, 20, and 30, thereby fixing the three tubes 10, 20, and 30. As shown in Figure 3 (F), in the cross section taken along line F-F, the outer circumferential surfaces of the sensor tube 10 (specifically, the base-end tube 12) and the OTW tube 20 (specifically, the base-end tube 22) are joined together.

[0035] The sensor tube 10, the OTW tube 20, and the RX tube 30 may be joined using any bonding agent such as an epoxy adhesive, or may be thermally welded. In the B-B cross section, the CC cross section, the D-D cross section, and the E-E 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 F-F cross section, the height LY of the catheter 1 is smaller than the width LZ of the catheter 1. As shown in FIGS. 3A to 3F , 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.

[0036] Returning to FIG. 1 , the explanation will be continued. The covering portion 50 is a resin layer for fixing the three tubes 10, 20, and 30 (specifically, the sensor tube 10, the OTW tube 20, and the RX tube 30). The covering portion 50 is provided within the section where the three tubes 10, 20, and 30 extend side by side, in other words, within the section proximal to the distal opening 201 and distal to the proximal opening 302. As shown in FIG. 1 , the covering portion 50 is preferably provided proximal to the distal opening 201, in other words, at a position away from the distal opening 201 toward the proximal end. This prevents the covering portion 50 from interfering with sensing (acquisition of image information) by the sensor 70 inserted into the sensor lumen 10L. As shown in FIGS. 3(D) and 3(E), the covering portion 50 thinly covers the outer-facing portions of the three tubes 10, 20, and 30 along the outer peripheries of the three tubes 10, 20, and 30. This allows the covering portion 50 to fix the three tubes 10, 20, 30 while maintaining the constrictions (concaves) formed in the adjacent portions of each tube 10, 20, 30 in the cross section of the catheter 1.

[0037] The branch connector 60 is a member having a bifurcated lumen and is disposed on the proximal end side of the catheter 1. The OTW tube 20 is inserted into one lumen of the branch connector 60. The sensor tube 10 is inserted into the other lumen of the branch connector 60. The first reinforcing member 61 is a cylindrical member disposed on the distal side of the branch connector 60. The first reinforcing member 61 reinforces the distal side of the branch connector 60 by covering the outer peripheries of the sensor tube 10 and the OTW tube 20 inserted into the branch connector 60.

[0038] The second reinforcing member 62 is a cylindrical member located closer to the proximal end than one branch of the branch connector 60. The second reinforcing member 62 reinforces the proximal end of the branch connector 60 by covering the outer periphery of the OTW tube 20 inserted into the branch connector 60. The third reinforcing member 63 is a cylindrical member located closer to the distal end than the connector 25. The third reinforcing member 63 reinforces the distal end of the connector 25 by covering the outer periphery of the OTW tube 20 inserted into the connector 25. The connector 25 is a member joined to the proximal end of the OTW tube 20. The connector 25 has a pair of wings for gripping by the surgeon. A proximal end opening 202 (device insertion port) that connects the proximal end of the OTW lumen 20L to the outside is formed at the proximal end of the connector 25.

[0039] The tubular member 64 is a cylindrical member located closer to the base end than the other branch of the branch connector 60. The tubular member 64 reinforces the base end of the branch connector 60 by covering the outer periphery of the sensor tube 10 inserted into the branch connector 60. The connector 65 is a member joined to the base end of the sensor tube 10. A housing for accommodating the connection terminal 75 of the sensor 70 is provided on the base end side of the connector 65. A fluid supply section 66 is provided on the outer periphery of the connector 65, and the fluid supply section 66 has a base end opening 102 formed therein, which communicates the base end of the sensor lumen 10L with the outside.

[0040] 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.

[0041] 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 shown by the white arrow in FIG. 2 , the surgeon can grasp the connector 65 and slide 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 covering portion 50, in other words, within a predetermined range MR including the distal end opening 201.

[0042] The distal tube 11 of the sensor tube 10, the distal tube 21 of the OTW tube 20, the RX tube 30, and the covering portion 50 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, the RX tube 30, and the covering portion 50 may be made of the same material or different materials.

[0043] The distal tube 21 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 distal tube 21 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. 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 stacked on top of each other.

[0044] 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.

[0045] The branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the tubular member 64, the connector 65, and the connector 25 can be made of a known resin material. The branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the tubular member 64, the connector 65, and the connector 25 may be made of the same material or different materials.

[0046] 4 and 5 are diagrams illustrating a method of using the catheter 1. Steps a1 to a6 shown below illustrate an example of attempting to recanalize a CTO (lesion) that has occurred in a blood vessel using an antegrade approach. However, the catheter 1 may also be used in a retrograde approach, or for procedures other than CTO recanalization.

[0047] (a1) The surgeon inserts the workhorse wire 200 into a blood vessel and delivers the distal end of the workhorse wire 200 to the vicinity of the CTO. (a2) The surgeon inserts the proximal end of the workhorse wire 200 from the distal opening 301 of the catheter 1, passes it through the RX lumen 30L, and pulls it out from the proximal opening 302 of the catheter 1 ( FIG. 4 ). (a3) ​​The surgeon pushes the catheter 1 along the workhorse wire 200 into the blood vessel and delivers the distal end of the catheter 1 to the vicinity of the CTO. Note that in step a3, the catheter 1 may be delivered to the vicinity of the CTO by passing it through a guiding catheter that has been inserted into the blood vessel in advance along the workhorse wire 200. (a4) The surgeon grasps the connector 65 and slides it back and forth (in the direction of the white arrow in Figure 5 ) to adjust the position of the probe 72 of the sensor 70 within the MR range, while checking the image displayed on the console terminal to align the position and orientation of the CTO and the distal opening 201. The term "position" refers to the position in the extension direction of the blood vessel, and the term "orientation" refers to the orientation circumferentially around the inner wall of the blood vessel. (a5) The surgeon inserts the distal end of the treatment device 300 through the proximal opening 202 of the catheter 1, passes it through the OTW lumen 20L, and protrudes it from the distal opening 201 of the catheter 1 ( Figure 5 ). (a6) The surgeon adjusts the position of the probe 72 of the sensor 70 within the MR range as needed, while checking the image displayed on the console terminal, to treat the CTO using the treatment device 300. As described above, any device, such as a plasma guidewire or a penetration guidewire, can be used as the treatment device 300.

[0048] The sensor tube 10, the OTW tube 20, and the RX tube 30 are also collectively referred to as the "shaft." The distal tube 11 and the distal tube 21 correspond to the "first tube," and the proximal tube 12 and the proximal tube 22 correspond to the "second tube." In this embodiment, "same" and "equal" do not necessarily mean exact agreement, but rather allow for differences due to manufacturing errors and the like. Furthermore, "constant" is synonymous with "approximately constant," meaning that the tube is approximately constant while allowing for variations due to manufacturing errors and the like.

[0049] Figure 6 is an enlarged longitudinal cross-sectional view of a portion of the sensor tube 10. Details of the sensor tube 10 that were omitted in Figure 1 will be described using Figure 6. The sensor tube 10 has a distal tube 11 (first tube) and a proximal tube 12 (second tube) that are indirectly connected to each other while being separated by a connecting member 13.

[0050] The distal tube 11 (first tube) has a main body portion 113 and a thin-walled portion 114. The main body portion 113 has a constant wall thickness T1 and a constant inner diameter Φ1. The thin-walled portion 114 is a portion having a wall thickness thinner than the wall thickness T1 of the main body portion 113 and is provided closer to the base end than the main body portion 113, in other words, at the base end of the distal tube 11. As shown in the figure, the thin-walled portion 114 is thinned from the inner circumferential surface while maintaining the same outer diameter as the main body portion 113.

[0051] The proximal tube 12 (second tube) has a small diameter section 123, a tapered section 124, and a large diameter section 125. The small diameter section 123 is the portion of the proximal tube 12 where the outer diameter and inner diameter are respectively smallest, and is provided on the distal side of the proximal tube 12. The tapered section 124 is the portion of the proximal tube 12 where the outer diameter and inner diameter are respectively gradually increased from the distal side to the proximal side. The tapered section 124 is provided closer to the proximal end than the small diameter section 123, in other words, between the small diameter section 123 and the large diameter section 125. The large diameter section 125 is the portion of the proximal tube 12 where the outer diameter and inner diameter are respectively largest, and is provided closer to the proximal end than the tapered section 124, in other words, closer to the proximal end of the proximal tube 12. The large diameter section 125 has a constant wall thickness T2 and a constant inner diameter Φ2. As shown in FIG. 6 , the distal end 121 of the proximal tube 12 is located closer to the proximal end than the proximal end 112 of the distal tube 11 .

[0052] Here, the thickness T2 of the large diameter portion 125 of the proximal tube 12 is thicker than the thickness T1 of the main body portion 113 of the distal tube 11 (T2 > T1). If the large diameter portion 125 or the main body portion 113 have non-uniform thicknesses, the maximum thickness values ​​are used for the thickness T2 of the large diameter portion 125 and the thickness T1 of the main body portion 113. Also, the inner diameter Φ2 of the large diameter portion 125 of the proximal tube 12 is larger than the inner diameter Φ1 of the main body portion 113 of the distal tube 11 (Φ2 > Φ1). If the large diameter portion 125 or the main body portion 113 have non-uniform inner diameters, the maximum inner diameter values ​​are used for the inner diameter Φ2 of the large diameter portion 125 and the inner diameter Φ1 of the main body portion 113. In the illustrated example, the inner diameter Φ13 of the connecting member 13 and the inner diameter Φ123 of the small diameter portion 123 of the base end tube 12 are the same size as the inner diameter Φ1 of the main body portion 113 of the tip end tube 11.

[0053] The connecting member 13 is a member that connects the distal tube 11 and the proximal tube 12. The connecting member 13 contacts the distal tube 11 on the distal side and contacts the proximal tube 12 on the proximal side. The connecting member 13 indirectly connects the distal tube 11 and the proximal tube 12 while separating the distal tube 11 and the proximal tube 12, in other words, while separating the distal tube 11 and the proximal tube 12. In other words, the distal tube 11 is not in contact with the proximal tube 12.

[0054] 6 , the distal end side of the connecting member 13 is integrated with the thin-walled portion 114 of the distal tube 11. Therefore, the distal end 131 of the connecting member 13 is located distally of the proximal end 112 of the distal tube 11 (first tube). On the other hand, the proximal end side of the connecting member 13 is integrated with the small-diameter portion 123 of the proximal tube 12. Therefore, the proximal end 132 of the connecting member 13 is located proximally of the distal end 121 of the proximal tube 12 (second tube).

[0055] Here, L1 is the axial distance from the base end 112 of the distal tube 11 (first tube) to the distal end 121 of the proximal tube 12 (second tube). L2 is the axial distance from the distal end 121 of the proximal tube 12 to the proximal end 132 of the connecting member 13. L3 is the axial distance from the distal end 131 of the connecting member 13 to the proximal end 112 of the distal tube 11. L4 is the axial distance of the inner circumferential surface of the connecting member 13. The axial distance L4 can also be said to be the axial distance of the exposed portion of the connecting member 13 on the inner circumferential surface of the sensor tube 10. The "axial distance" refers to the linear distance along the central axis O of the sensor tube 10, and can also be expressed as the linear distance along the longitudinal direction of the sensor tube 10 or the linear distance along the X-axis direction in FIG. 6 .

[0056] 6, the axial distance L1 is shorter than the sum of the axial distances L2 and L3 (L1<L2+L3). Furthermore, the axial distance L1 is shorter than at least one of the axial distances L2 and L3. In the illustrated example, the axial distance L1 is shorter than the axial distance L2 and also shorter than the axial distance L3 (L1<L2 and L1<L3). Furthermore, the axial distance L4 is longer than the axial distance L1 (L4>L1).

[0057] The distal tube 11 (first tube) of this embodiment is, for example, a three-layer tube having an inner layer, a middle layer, and an outer layer made of different thermoplastic resins. The melting point of the distal tube 11 is defined as the "first temperature." The proximal tube 12 (second tube) of this embodiment is, for example, a PEEK tube. The melting point of the proximal tube 12 is defined as the "second temperature." In this case, the first temperature and the second temperature are different temperatures, and the first temperature is lower than the second temperature (first temperature < second temperature). In the case of a tube made of multiple layers of different materials, such as the distal tube 11 described above, the "first temperature" or "second temperature" is the highest melting point of the multiple layers.

[0058] In this embodiment, the connection member 13 is, for example, a heat-shrinkable tube made of fluororesin (PTFE, PFA). The melting point of the connection member 13 is defined as the "third temperature." In this case, the third temperature is higher than the lower of the first temperature and the second temperature. In this embodiment, since the first temperature is lower than the second temperature, adding the melting point of the connection member 13 results in the relationship: first temperature < third temperature < second temperature.

[0059] Such a sensor tube 10 can be fabricated, for example, by the following steps b1 to b5. In the following examples, for convenience of explanation, the material of the distal tube 11 will be referred to as a "three-layer tube," the material of the proximal tube 12 will be referred to as a "PEEK tube," and the material of the connecting member 13 will be referred to as a "PTFE tube." However, the materials of the distal tube 11, the proximal tube 12, and the connecting member 13 are not limited to those illustrated. The melting point of the three-layer tube is the same as that of the distal tube 11 (first temperature), the melting point of the PEEK tube is the same as that of the proximal tube 12 (second temperature), and the melting point of the PTFE tube is the same as that of the connecting member 13 (third temperature).

[0060] (b1) The distal end of the PEEK tube is processed to form the narrowed portion 123 and tapered portion 124 described in FIG. 6 . (b2) With the inner metal inserted, a cylindrical PTFE tube is placed over the distal end of the PEEK tube (specifically, the narrowed portion 123 and tapered portion 124 formed in step b1). (b3) The entire PEEK tube and PTFE tube are heated with a hot gun or the like. The heating causes the PEEK tube and PTFE tube to thermally shrink. (b4) The proximal end of the three-layer tube is flared (a process for expanding the proximal end to increase its diameter), and then the proximal end of the three-layer tube is placed over the distal end of the PTFE tube (the PTFE tube integrated with the PEEK tube in step b3). (b5) The entire three-layer tube, PTFE tube, and PEEK tube are heated with a hot gun or the like. By heating, the three-layer tube and the PEEK tube are integrated via the PTFE tube to form the sensor tube 10 consisting of the distal tube 11, the connecting member 13, and the proximal tube 12 having the structure described in Figure 6.

[0061] FIG. 7 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube 10x of the comparative example. Unlike the sensor tube 10 described in FIG. 6 , the sensor tube 10x of the comparative example has a distal tube 11x and a proximal tube 12x directly connected without the connecting member 13. The sensor tube 10x of the comparative example can be fabricated by, after step b1 described above, covering the distal end of the PEEK tube (specifically, the narrow-diameter portion 123 and tapered portion 124 formed in step b1) with a tri-layer tube in step b2 while inserting an inner metal, and then heating the entire PEEK tube and tri-layer tube. Note that steps b3 to b5 are not performed in the comparative example. In the sensor tube 10x of the comparative example, the difference between the melting point (first temperature) of the tri-layer tube and the melting point (second temperature) of the PEEK tube is large. Therefore, when the entire PEEK tube and tri-layer tube are heated, the tri-layer tube melts before the PEEK tube shrinks. As a result, in the sensor tube 10x of the comparative example, the distal tube 11x penetrates into the inner peripheral surface of the proximal tube 12x, creating an internal burr E. When the sensor tube 10x is bent, the internal burr E protrudes toward the inner peripheral surface, causing other devices in the sensor lumen 10L to become caught. Furthermore, even when the sensor tube 10x is not bent, the internal burr E can cause other devices to become caught depending on their shape.

[0062] In this regard, the sensor tube 10 of this embodiment shown in Figure 6 undergoes the above-mentioned procedure b3 (the step of thermally shrinking the PEEK tube and the PTFE tube) using a PTFE tube whose melting point is a third temperature higher than the lower of the first and second temperatures. This prevents the three-layer tube from melting before the PEEK tube shrinks, which occurred in the comparative example, resulting in the formation of an internal flash E at the boundary between the PEEK tube and the three-layer tube. Furthermore, because the sensor tube 10 of this embodiment integrates the distal tube 11, the proximal tube 12, and the connecting member 13 using heat, it prevents the occurrence of a locally increased bending stiffness at the adhesive-bonded portion compared to when the distal tube 11 and the proximal tube 12 are bonded using an adhesive.

[0063] 6 has been described with reference to the sensor tube 10. However, the OTW tube 20 also has a similar configuration to the sensor tube 10. That is, in the OTW tube 20, the distal tube 21 (first tube) and the proximal tube 22 (second tube) are indirectly connected while being separated by a connecting member. The first temperature, which is the melting point of the distal tube 21, the second temperature, which is the melting point of the proximal tube 22, and the third temperature, which is the melting point of the connecting member, also have the same magnitude relationship as the sensor tube 10. Furthermore, the axial distances L1 to L4 of the respective parts of the distal tube 21 and the proximal tube 22 are also the same as those of the sensor tube 10. The wall thicknesses and inner diameters of the distal tube 21 and the proximal tube 22 are also the same.

[0064] The sensor tube 10 and the OTW tube 20 are tubes that constitute the catheter 1. However, the sensor tube 10 may be used as a "medical tube" by itself or with a connector or the like attached to the base end.

[0065] As described above, in the catheter 1 (medical device) of the first embodiment, the distal tube 11 (first tube) and the proximal tube 12 (second tube), which are arranged in the axial direction, are indirectly connected while being separated by the connecting member 13. The melting point of this connecting member 13 is a third temperature higher than the lower of the melting point (first temperature) of the distal tube 11 and the melting point (second temperature) of the proximal tube 12, thereby preventing the occurrence of internal burrs in the sensor tube 10. In other words, the sensor tube 10 of the first embodiment prevents the occurrence of internal burrs E compared to when the distal tube 11x and the proximal tube 12x, which have a large difference in melting point, are arranged without a connecting member (the sensor tube 10x of the comparative example described in FIG. 7 ). As a result, the sensor tube 10 of the first embodiment prevents the occurrence of internal burrs at the connection portion of the two axially arranged tubes (the distal tube 11 and the proximal tube 12). These points also apply to the OTW tube 20. Therefore, when using the catheter 1, it is possible to prevent other devices (sensors 70) from getting caught in the sensor lumen 10L of the sensor tube 10, or other devices (therapeutic devices 300) from getting caught in the OTW lumen 20L of the OTW tube 20, thereby preventing the procedure from being hindered due to the catch and preventing the sensor tube 10 or the OTW tube 20 from being damaged due to the catch.

[0066] Furthermore, in the catheter 1 (medical device) of the first embodiment, the tip 131 of the connecting member 13 in the sensor tube 10 is located more distal than the base end 112 of the distal tube 11 (first tube), thereby increasing the contact area between the connecting member 13 and the distal tube 11. Furthermore, the base end 132 of the connecting member 13 is located more proximal than the tip 121 of the proximal tube 12 (second tube), thereby increasing the contact area between the connecting member 13 and the proximal tube 12.

[0067] Furthermore, in the catheter 1 (medical device) of the first embodiment, in the sensor tube 10, the axial distance L1 from the base end 112 of the tip-side tube 11 (first tube) to the tip 121 of the base-side tube 12 (second tube) is shorter than the sum of the axial distance L2 from the tip 121 of the base-side tube 12 to the base end 132 of the connecting member 13 and the axial distance L3 from the tip 131 of the connecting member 13 to the base end 112 of the tip-side tube 11, thereby mitigating the rigidity gap in the axial direction of the sensor tube 10.

[0068] Furthermore, in the catheter 1 (medical device) of the first embodiment, in the sensor tube 10, the axial distance L1 from the base end 112 of the tip-side tube 11 (first tube) to the tip 121 of the base-side tube 12 (second tube) is shorter than at least one of the axial distance L2 from the tip 121 of the base-side tube 12 to the base end 132 of the connecting member 13 and the axial distance L3 from the tip 131 of the connecting member 13 to the base end 112 of the tip-side tube 11, thereby mitigating the rigidity gap in the axial direction of the sensor tube 10.

[0069] Furthermore, in the catheter 1 (medical device) of the first embodiment, the connecting member 13 in the sensor tube 10 is formed from fluororesin, and the axial distance L4 of the inner surface of the connecting member 13 is longer than the axial distance L1 from the base end 112 of the tip-side tube 11 (first tube) to the tip 121 of the base-end tube 12 (second tube), thereby improving the sliding properties of other devices on the inner surface of the connecting member 13.

[0070] Furthermore, in the catheter 1 (medical device) of the first embodiment, the maximum inner diameter Φ2 of the base-side tube 12 (second tube) in the sensor tube 10 is larger than the maximum inner diameter Φ1 of the distal-side tube 11 (first tube), so the diameter of the sensor lumen 10L formed by the distal-side tube 11, the base-side tube 12, and the connecting member 13 can be sized to conform to the outer diameter changes of other general devices. Also, the wall thickness T2 of the base-side tube 12 is thicker than the wall thickness T1 of the distal-side tube 11, so the base-side side of the sensor tube 10 can be made more rigid than the distal side.

[0071] Furthermore, the catheter 1 (medical device) of the first embodiment is configured as a catheter 1 in which a sensor 70 that acquires image information is inserted into the sensor lumen 10L formed by the distal tube 11 (first tube), the proximal tube 12 (second tube), and the connecting member 13, so that a procedure can be performed using the image information (ultrasound image) acquired from the sensor 70.

[0072] 8 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube 10A according to a second embodiment. A catheter 1A according to the second embodiment includes a sensor tube 10A instead of the sensor tube 10 in the configuration described in the first embodiment. The sensor tube 10A includes a base-end tube 12A instead of the base-end tube 12 and a connection member 13A instead of the connection member 13 in the configuration described in the first embodiment.

[0073] The axial length of the thin-diameter portion 123 of the proximal tube 12A is shorter than that of the configuration of the first embodiment ( FIG. 6 ). The axial length of the connecting member 13A is longer than that of the configuration of the first embodiment ( FIG. 6 ). Here, the axial distance from the proximal end 112 of the distal tube 11 (first tube) to the distal end 121 of the proximal tube 12A (second tube) is defined as L1A. The axial distance from the distal end 121 of the proximal tube 12A to the proximal end 132 of the connecting member 13A is defined as L2A. The axial distance from the distal end 131 of the connecting member 13A to the proximal end 112 of the distal tube 11 is defined as L3. The axial distance of the inner circumferential surface of the connecting member 13A is defined as L4A. In this case, the axial distance L1A is longer than the sum of the axial distances L2A and L3 (L1A > L2A + L3). Furthermore, the axial distance L1A is longer than the axial distance L2A and longer than the axial distance L3 (L1A>L2A and L1A>L3). Furthermore, the axial distance L4A is longer than the axial distance L1A (L4A>L1A).

[0074] In this way, the axial distances L1A, L2A, L3, and L4 of the various portions of the sensor tube 10A, and the relative sizes of these distances, can be changed as desired. The sensor tube 10A and catheter 1A of the second embodiment described above can also achieve the same effects as those of the first embodiment described above.

[0075] 9 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube 10B according to a third embodiment. The catheter 1B of the third embodiment includes a sensor tube 10B instead of the sensor tube 10 in the configuration described in the first embodiment. The sensor tube 10B includes a distal tube 11B instead of the distal tube 11 and a connecting member 13B instead of the connecting member 13 in the configuration described in the first embodiment.

[0076] The distal tube 11B does not have the thin-walled portion 114 described in the first embodiment ( FIG. 6 ). Accordingly, the distal side of the connecting member 13B does not have a portion integrated with the thin-walled portion 114. That is, in the third embodiment, the distal end 131 of the connecting member 13B is located at the same position as the base end 112 of the distal tube 11B (first tube).

[0077] Here, the axial distance from the proximal end 112 of the distal tube 11B (first tube) to the distal end 121 of the proximal tube 12 (second tube) is defined as L1. The axial distance from the distal end 121 of the proximal tube 12 to the proximal end 132 of the connecting member 13B is defined as L2. The axial distance from the distal end 131 of the connecting member 13B to the proximal end 112 of the distal tube 11B is defined as L3B. The axial distance of the inner circumferential surface of the connecting member 13B is defined as L4B. In this case, the axial distance L1 is shorter than the sum of the axial distances L2 and L3B (L1 < L2 + L3B). Furthermore, the axial distance L1 is shorter than at least one of the axial distances L2 and L3B. In the illustrated example, the axial distance L1 is shorter than the axial distance L2 (L1 < L2). Note that in the illustrated example, the axial distance L3B is zero (L3B = 0). On the other hand, the axial distance L4B is equal to the axial distance L1 (L4B=L1).

[0078] In this way, the axial distances L1, L2, L3B, and L4B of each part and the relative sizes thereof can be changed as desired in the sensor tube 10B. The sensor tube 10B and catheter 1B of the third embodiment described above can also achieve the same effects as those of the first embodiment described above.

[0079] 10 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube 10C according to a fourth embodiment. The catheter 1C of the fourth embodiment includes a sensor tube 10C instead of the sensor tube 10 in the configuration described in the first embodiment. The sensor tube 10C includes a base-end tube 12C instead of the base-end tube 12 in the configuration described in the first embodiment.

[0080] The proximal tube 12C has a thin-walled portion 123C, a tapered portion 124C, and a main body portion 125C. The thin-walled portion 123C has a thickness thinner than the wall thickness T2C of the main body portion 125C and is located on the distal side of the proximal tube 12C. The tapered portion 124C is a portion of the proximal tube 12C whose outer diameter gradually increases from the distal side to the proximal side. The tapered portion 124C is located closer to the proximal end than the thin-walled portion 123C, in other words, between the thin-walled portion 123C and the main body portion 125C. The main body portion 125C is the portion of the proximal tube 12C where the outer diameter is largest and is located closer to the proximal end than the tapered portion 124C, in other words, closer to the proximal end of the proximal tube 12C. Here, the thickness T2C of the main body 125C of the proximal tube 12C is equal to the thickness T1 of the main body 113 of the distal tube 11 (T2C = T1). Also, the inner diameter Φ2C of the main body 125C of the proximal tube 12C is equal to the inner diameter Φ1 of the main body 113 of the distal tube 11 (Φ2C = Φ1).

[0081] In this way, the maximum wall thickness and inner diameter of the distal tube 11 and the proximal tube 12C in the sensor tube 10C can be changed as desired. The sensor tube 10C and catheter 1C of the fourth embodiment described above can also achieve the same effects as those of the first embodiment. Furthermore, the sensor tube 10C of the fourth embodiment can further reduce the change in rigidity between the distal tube 11 and the proximal tube 12C.

[0082] 11 is an enlarged longitudinal cross-sectional view of a portion of a sensor tube 10D according to a fifth embodiment. A catheter 1D according to the fifth embodiment includes a sensor tube 10D instead of the sensor tube 10 in the configuration described in the first embodiment. The sensor tube 10D includes a distal tube 11D instead of the distal tube 11, a proximal tube 12D instead of the proximal tube 12, and a connecting member 13D instead of the connecting member 13 in the configuration described in the first embodiment.

[0083] The distal tube 11D does not have the thin-walled portion 114 described in the first embodiment ( FIG. 6 ). Accordingly, the distal side of the connecting member 13D does not have a portion integrated with the thin-walled portion 114. That is, in the fifth embodiment, the distal end 131 of the connecting member 13D is located at the same position as the proximal end 112 of the distal tube 11D (first tube). The proximal tube 12D does not have the small-diameter portion 123 and tapered portion 124 described in the first embodiment ( FIG. 6 ), and has a main body portion 125D instead of the large-diameter portion 125. Accordingly, the proximal side of the connecting member 13D does not have a portion integrated with the thin-diameter portion 123. That is, in the fifth embodiment, the proximal end 132 of the connecting member 13D is located at the same position as the distal end 121 of the proximal tube 12D (second tube).

[0084] As in the fourth embodiment (FIG. 10), the thickness T2D of the main body 125D of the proximal tube 12D is equal to the thickness T1 of the main body 113 of the distal tube 11D (T2D=T1). The inner diameter Φ2D of the main body 125D of the proximal tube 12D is equal to the inner diameter Φ1 of the main body 113 of the distal tube 11D (Φ2D=Φ1).

[0085] As described above, in the sensor tube 10D, the configurations of the distal tube 11D, the proximal tube 12D, and the connecting member 13D can be modified in various ways, and the positional relationship of the distal end 131 and the proximal end 132 of the connecting member 13D with respect to the distal tube 11D and the proximal tube 12D can be changed as desired. The sensor tube 10D and catheter 1D of the fifth embodiment described above can also achieve the same effects as those of the first embodiment described above.

[0086] Sixth Embodiment Fig. 12 is an explanatory diagram illustrating the configuration of a catheter 1E of a sixth embodiment. The catheter 1E of the sixth embodiment includes an OTW tube 20E instead of the OTW tube 20 in the configuration described in the first embodiment. The OTW tube 20E does not include the distal tube 21 and proximal tube 22 described in the first embodiment (Figs. 1, 6, etc.), but is configured as a single tube. As described above, the configuration of the catheter 1E can be modified in various ways, and only the sensor tube 10 may have the configuration described in Fig. 6. Alternatively, the sensor tube 10 may be configured as a single tube, and only the OTW tube 20E may have the configuration described in Fig. 6. The catheter 1E of the sixth embodiment described above can also achieve the same effects as the first embodiment described above.

[0087] Seventh Embodiment Figure 13 is an explanatory diagram illustrating the configuration of a catheter 1F according to a seventh embodiment. The catheter 1F of the seventh embodiment includes an OTW tube 20, a third reinforcing member 63, and a connector 25. The OTW tube 20 has a configuration similar to that of the sensor tube 10 described in Figure 6. That is, in the OTW tube 20, the distal tube 21 (first tube) and the proximal tube 22 (second tube) are indirectly connected while being separated by a connecting member. Furthermore, the first temperature, which is the melting point of the distal tube 21, the second temperature, which is the melting point of the proximal tube 22, and the third temperature, which is the melting point of the connecting member, have the same magnitude relationship as the sensor tube 10. Furthermore, the axial distances L1 to L4 between the distal tube 21 and the proximal tube 22 are also similar to those of the sensor tube 10. The wall thicknesses and inner diameters of the distal tube 21 and the proximal tube 22 are also similar. In this way, the medical device (catheter 1F) may be configured solely with the OTW tube 20. The catheter 1F of the seventh embodiment as described above can also achieve the same effects as those of the first embodiment described above.

[0088] <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.

[0089] [Modification 1] In the above first to seventh embodiments, one example of the configuration of the catheters 1, 1A to 1F is shown. However, the configuration of the catheters 1, 1A to 1F can be modified in various ways.

[0090] For example, the outer peripheral surface of the covering portion 50, or the outer peripheral surface of the catheter 1 including the covering portion 50, may be coated with a hydrophilic resin or a hydrophobic resin. For example, the sensor 70 is built into the sensor lumen 10L of the sensor tube 10 and is configured to be unremovable from the catheter 1. However, the sensor 70 may also be configured to be removable from the catheter 1. In other words, the catheter 1 does not have to include the sensor 70 as a component.

[0091] For example, at least one of the distal tip 40, the first marker 41, and the second marker 42 may be omitted. For example, the shapes of the distal tip 40, the first marker 41, and the second marker 42 can be changed as desired. The distal tip 40 may have a constant outer diameter from the distal end to the proximal end, and the cross-sectional shape may be asymmetrical. The first marker 41 and the second marker 42 may have a shape other than a ring shape (for example, a ring shape cut at an arbitrary angle, a wire shape, or a coil shape formed by spirally winding a wire).

[0092] For example, the positions of the distal tip 40, the first marker 41, and the second marker 42 can be changed as desired. The first marker 41 may be positioned at a position other than adjacent to the proximal end of the distal tip 40 (for example, a position distant from the distal tip 40). The second marker 42 may be positioned at a position other than adjacent to the distal end of the distal opening 201 of the OTW tube 20 (for example, a position distant from the distal opening 201). The first marker 41 and the second marker 42 may be positioned on a tube other than the RX tube 30 (the sensor tube 10 or the OTW tube 20). The first marker 41 and the second marker 42 may be positioned on the same tube as described above, or on different tubes.

[0093] For example, the covering portion 50 may be omitted. For example, in the examples of Figures 3(D) and 3(E), the covering portion 50 is composed of a single layer, but the covering portion 50 may be composed of two or more layers. For example, in the examples of Figures 3(D) and 3(E), the covering portion 50 thinly covers the outer peripheries of the three tubes 10, 20, and 30, thereby maintaining the constrictions (recesses) formed in the adjacent portions of the tubes 10, 20, and 30. However, the covering portion 50 may be configured to fill the constrictions formed in the adjacent portions of the tubes 10, 20, and 30 so that the cross-sectional shape of the catheter 1 is circular or elliptical.

[0094] For example, the shapes of the branch connector 60, the first reinforcing member 61 to the third reinforcing member 63, the tubular member 64, the connector 65, and the connector 25 described above are merely examples and may be changed as desired. For example, at least a portion of the branch connector 60, the first reinforcing member 61, the second reinforcing member 62, and the tubular member 64 may be configured as a single member or may be omitted. For example, the third reinforcing member 63 and the connector 25 may be configured as a single member. For example, the tubular member 64 may be provided with a mechanism (e.g., scales or stoppers provided at predetermined intervals in the longitudinal direction, or scales or stoppers provided at predetermined intervals in the circumferential direction) that assists in adjusting at least one of the front-to-rear position of the sensor 70 and the orientation of the sensor 70 in the circumferential direction.

[0095] [Modification 2] The configurations of the catheters 1, 1A to 1F of the first to seventh embodiments and the configuration of the catheters 1, 1A to 1F of Modification 1 may be combined as appropriate. The configuration of the sensor tube 10 described in the second to fifth embodiments may be incorporated into the catheter 1E described in the sixth embodiment, or into the catheter 1F described in the seventh embodiment.

[0096] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

Claims

1. It is a medical device, A first tube whose melting point is the first temperature, A second tube having a melting point different from the first temperature, and whose tip is located closer to the base end than the base end of the first tube, A connecting member having a third melting point higher than the lower of the first and second temperatures, which contacts the first tube and the second tube respectively, and connects them while separating them, A medical device equipped with the following features.

2. A medical device according to claim 1, The tip of the connecting member is located on the tip side of the base end of the first tube. A medical device in which the base end of the connecting member is located on the base end side of the tip of the second tube.

3. A medical device according to claim 1, The aforementioned connecting member is a heat-shrinkable tube, in this medical device.

4. A medical device according to any one of claims 1 to 3, A medical device in which the axial distance L1 from the base end of the first tube to the tip of the second tube is shorter than the sum of the axial distance L2 from the tip of the second tube to the base end of the connecting member and the axial distance L3 from the tip of the connecting member to the base end of the first tube.

5. A medical device according to any one of claims 1 to 3, A medical device in which the axial distance L1 from the base end of the first tube to the tip of the second tube is shorter than at least one of the axial distance L2 from the tip of the second tube to the base end of the connecting member and the axial distance L3 from the tip of the connecting member to the base end of the first tube.

6. A medical device according to any one of claims 1 to 3, The connecting member is made of fluororesin, A medical device in which the axial distance L4 of the inner circumferential surface of the connecting member is longer than the axial distance L1 from the base end of the first tube to the tip of the second tube.

7. A medical device according to any one of claims 1 to 3, A medical device in which the maximum inner diameter of the second tube is greater than the maximum inner diameter of the first tube.

8. A medical device according to any one of claims 1 to 3, A medical device in which the wall thickness of the second tube is greater than the wall thickness of the first tube.

9. A medical device according to any one of claims 1 to 3, A medical device in which a sensor for acquiring image information is inserted into a lumen formed by the first tube, the second tube, and the connecting member.

Images