conduit

Abstract

A catheter capable of improving the smoothness of a lumen is provided. A balloon catheter includes an outer shaft (10) for insertion into a body, having a main lumen (12) extending in an axial direction from a base end side toward a tip end side, and a second member exposed to the main lumen (12) in a portion of an inner peripheral surface of the outer shaft (10), the second member having lower friction than a first member (inner shaft (41)) constituting the inner peripheral surface of the outer shaft (10). The balloon catheter further includes a sub shaft (101-112) having a sub lumen (101L-112L) extending in the axial direction, the sub shaft (101-112) being constituted by the second member, a portion of an outer peripheral surface of the sub shaft (101-112) being exposed to the main lumen (12) in a portion of the inner peripheral surface of the outer shaft (10).

Description

Technical Field

[0001] This disclosure relates to a catheter that is inserted into the body. Background Technology

[0002] A catheter is a medical tube inserted into the body for diagnostic and treatment purposes. Among catheters, those inserted into tubular organs such as blood vessels, trachea, digestive tract, common bile duct, and pancreatic duct, their connections (entrances / exits), or through openings formed in the body for diagnostic and treatment purposes (e.g., the opening from the stomach or duodenal bulb to the common bile duct) to dilate and treat target sites are called balloon catheters. Patent Document 1 discloses an example of such a balloon catheter. The outer shaft of the balloon catheter in Patent Document 1 has: a central lumen for insertion of an inner shaft; and multiple peripheral lumens located around the central lumen for draining fluid used to inflate the balloon.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2021 / 130877 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the outer shaft of Patent Document 1, the central cavity is formed by a PEEK resin (polyether ether ketone resin) tube with excellent mechanical properties, but its friction is high, so it may be difficult to insert the inner shaft, etc.

[0008] This disclosure is an invention made in view of the following situation, with the aim of providing a catheter that can improve the smoothness of the lumen.

[0009] Technical solution

[0010] To solve the above problems, a catheter according to a certain embodiment of the present invention includes: a first shaft for insertion into the body, having a first cavity extending axially from the base side toward the tip side; and a second member, which together with the first member, which is a main component of the first shaft, forms an inner peripheral surface defining the first cavity, wherein the friction of the second member is lower than that of the first member.

[0011] According to this scheme, the smoothness of the first cavity can be improved by forming the inner circumferential surface of the first shaft with a second component of low friction.

[0012] Invention Effects

[0013] The catheter disclosed herein can improve lumen patency. Attached Figure Description

[0014] Figure 1 This refers to the entire balloon catheter.

[0015] Figure 2 It is a three-dimensional diagram showing the balloon during expansion.

[0016] Figure 3 This is a cross-sectional view of the balloon during expansion.

[0017] Figure 4 This is a magnified view of the base of the balloon.

[0018] Figure 5 This is a magnified view of the tip of the balloon.

[0019] Figure 6 It is a sectional view of the outer axis.

[0020] Figure 7 It is relative to Figure 4 A picture after the balloon and other components have been removed.

[0021] Figure 8 An example illustrating the manufacturing method of an outer shaft.

[0022] Figure 9 This represents a variation of the second component. Detailed Implementation

[0023] Hereinafter, with reference to the accompanying drawings, a detailed description of the embodiments (hereinafter also referred to as embodiments) for carrying out the present invention will be provided. In the description and / or drawings, the same or equivalent constituent elements, components, processes, etc., are labeled with the same reference numerals, and repeated descriptions are omitted. For the sake of simplicity, the scale and shape of the illustrated parts are set in a convenient manner, and are not interpreted as limiting unless specifically mentioned. The embodiments are illustrative and do not limit the scope of the present invention. All features described in the embodiments, and combinations thereof, are not necessarily essential features of the present invention.

[0024] This disclosure can be applied to any type of catheter, but in this embodiment, a balloon catheter with a strip-shaped electrode formed on the surface of the balloon for applying high-frequency electricity (hereinafter also referred to as high frequency) will be described as an example. This balloon catheter is used for catheter ablation (hereinafter also referred to as ablation) or radiofrequency ablation (RFA) as a treatment method for arrhythmias. The balloon, inserted into an abnormal site (the blood vessel itself, the surrounding tissue of the lesion, etc.) within a blood vessel causing the arrhythmia, expands by supplying a dilating fluid such as saline to its interior, bringing the electrode on the surface close to or in contact with the abnormal site. In this state, the abnormal site is ablated by applying high frequency to the electrode.

[0025] Figure 1This refers to the entire balloon catheter 100 of this embodiment. The balloon catheter 100 includes: an outer shaft 10 (hereinafter also simply referred to as shaft 10), serving as a first shaft for insertion into the body; and a handle 20, which is fitted to the base of the outer shaft 10 or to the outside of the body. Figure 1 (right side); and balloon 30, fitted to the top side or inner side of the outer shaft 10 (in the middle); Figure 1 (Left side of the outer shaft 10), which can expand by fluid supplied from the base end side of the outer shaft 10. The flexible tubular outer shaft 10 consists of a tubular base end side shaft 10A extending from the handle portion 20 to the base end of the balloon 30, communicating with the base end side shaft 10A and extending axially ( Figure 1 It consists of a tubular tip side shaft 10B that extends through the balloon 30 in the left and right directions, and a tip tip 46 assembled at the tip of the tip side shaft 10B.

[0026] The balloon catheter 100 is used for ablation of lesions. As described later, a strip of electrodes is formed on the surface of the balloon 30 along an axial direction from the base to the tip. The balloon 30, inserted into an abnormal site within a blood vessel or other vascular system, expands by supplying a dilating fluid, such as saline, to its interior via the handle 20 and the outer shaft 10, bringing the electrode array close to or in contact with the abnormal site. In this state, high-frequency ablation of the electrode array is applied to the abnormal site.

[0027] An electrical connector 21, a fluid supply port 22, a fluid discharge port 23, and a device port 24 are provided on the base end side of the handle portion 20. The electrical connector 21 is electrically connected to the electrode assembly on the surface of the balloon 30 via a cable 26, the handle portion 20, the shaft 10 (base end side shaft 10A and / or top end side shaft 10B), and a wire inside the balloon 30, from the base end side toward the top end side. Therefore, the electrical connector 21, connected to a high-frequency power supply (not shown), can apply a high frequency to the electrode assembly on the surface of the balloon 30. Furthermore, by connecting the electrical connector 21 to a control device or measuring device such as a computer, data such as the potential of the treatment area measured by the electrode assembly on the surface of the balloon 30, and temperature data of the treatment area measured by a temperature sensor (thermocouple) described later, can be obtained.

[0028] Fluid supply port 22 supplies fluid for inflating balloon 30; specifically, it supplies an inflating fluid obtained by appropriately mixing contrast agent with sterile distilled water and physiological saline. Fluid supply port 22 communicates with the interior of balloon 30 via a flow path from the base to the tip through fluid supply tube 27, handle 20, and shaft 10 (sub-shafts 101-105 described later). When inflating fluid is supplied to the interior of balloon 30 via fluid supply port 22, balloon 30 inflates. Fluid discharge port 23 discharges inflating fluid from the interior of balloon 30. Fluid discharge port 23 communicates with the interior of balloon 30 via a flow path from the base to the tip through fluid discharge tube 28, handle 20, and shaft 10 (sub-shafts 107-111 described later). When inflating fluid is discharged from the interior of balloon 30 via fluid discharge port 23, balloon 30 contracts. It should be noted that the balloon 30 can also be expanded while the internal expansion fluid flows or circulates by simultaneously supplying expansion fluid into the balloon 30 through the fluid supply port 22 and discharging expansion fluid out of the balloon 30 through the fluid discharge port 23.

[0029] A guidewire is inserted into the device port 24. This guidewire guides a medical instrument, such as a camera or forceps at the tip, and a balloon 30 for diagnosis and treatment, to the treatment site. In this embodiment, an example of the guidewire being inserted into the device port 24 will be described. As will be described later, the base-side shaft 10A of the shaft 10 is composed of an outer shaft (hereinafter, for convenience, it will sometimes be referred to as 10A) and an inner shaft 41, and the tip-side shaft 10B of the shaft 10 is composed of an inner shaft 41 (hereinafter, for convenience, it will sometimes be referred to as 10B). The device port 24 communicates with the inner shaft 41, which extends axially between the base and tip of the balloon catheter 100. The guidewire introduced from the device port 24 passes through the inner shaft 41 and extends out of the balloon catheter 100 from the tip 46. Therefore, by inserting the base of the guidewire, which has been pre-inserted to the treatment site, into the tip of the balloon catheter 100, the balloon 30 can reach the treatment site while being guided by the guidewire. The generally cylindrical space extending axially inside the tubular inner shaft 41 is referred to as a wire lumen, etc., when it is mainly used for guide wire insertion, but is collectively referred to as the inner cavity below. In addition, as described later, the inner shaft 41 is inserted into the outer cavity, which is the generally cylindrical space extending axially inside the outer shaft 10 (especially the outer shaft 10A), that is, the outer cavity serving as the first cavity.

[0030] The balloon 30 includes: a middle portion 31, which can expand into a cylindrical shape by an expansion fluid supplied from the fluid supply port 22; a tip portion 33, which is mounted on a tip-side shaft 10B (inner shaft 41) at a position closer to the tip than the middle portion 31; and a base portion 35, which is mounted on a base-side shaft 10A (outer shaft 10) at a position closer to the base than the middle portion 31. The middle portion 31 is the part that axially connects the tip portion 33 and the base portion 35 mounted on the shaft 10, and is hereinafter also referred to as the straight portion 31. The tip portion 33 of the balloon 30 includes: a tip-side neck 331, which is mounted on the tip-side shaft 10B (inner shaft 41) or a tip tip 46; and a tip-side conical portion 332 (hereinafter also referred to as the tip-side conical portion 332), which is formed into a pointed or truncated cone shape from the tip of the straight portion 31 toward the tip-side neck 331. The base end portion 35 of the balloon 30 includes: a base end neck 351, which is fitted to the outer periphery of the base end shaft 10A (outer shaft 10) on the base end side; and a base end tapered portion 352 (hereinafter also referred to as base end tapered portion 352), which is formed into a pointed or truncated cone shape from the base end of the straight portion 31 toward the base end neck 351.

[0031] Figure 2 This is a perspective view of the balloon 30 during expansion. A plurality of thin-film strip electrodes 40 are formed on the surfaces of the tip portion 33 and the straight portion 31 of the balloon 30 along an axial direction from the tip side to the base side. The strip electrodes 40 may also be formed on the surface of the base end portion 35 of the balloon 30. The plurality of strip electrodes 40 are circumferentially spaced throughout their respective lengths of the balloon 30. It should be noted that the plurality of strip electrodes 40 may also be connected at least on the tip side and / or the tip neck 331 of the tip-side conical portion 332 without circumferential gaps. In the illustrated example, the circumferential width and spacing of each strip electrode 40 are approximately constant, but they may also be different.

[0032] To improve the foldability of the balloon 30, the width of each strip electrode 40 in the tip portion 33 (and / or base portion 35) may be smaller than the width of each strip electrode 40 in the middle portion 31. For example, the width of the strip electrode 40 in the tip-side cone portion 332 may be monotonically reduced from the maximum width in the straight portion 31 to the minimum width in the tip-side neck 331.

[0033] Also refer to the illustrative representation of the inclusion Figure 2 The cross section formed by the plane of the central axis of shaft 10 Figure 3The structure of the tip portion 33 of the balloon 30 will be described below. An inner cavity 12 (hereinafter also referred to as the central cavity 12 or main cavity 12) is formed inside the tip side shaft 10B (inner shaft 41) that extends axially through the interior of the balloon 30, allowing a guidewire or similar device to communicate with the device port 24. The outer diameter of the tip side shaft 10B is, for example, 1.4 mm, and the inner diameter of the tip side shaft 10B (outer diameter of the central cavity 12) is, for example, 1.1 mm. A generally cylindrical tip tip 46 (part of the shaft 10) is provided at the tip of the tip side shaft 10B, covering and protecting the tip portion of the tip side shaft 10B, including its outer periphery. The outer diameter of the tip tip 46 is, for example, 2.0 mm, and the inner diameter of the tip tip 46 is the same as the inner diameter of the tip side shaft 10B, for example, 1.1 mm. The tip tip 46 is formed of a hard resin or the like. The guide wire and other devices passing through the inner lumen 12 extend from the opening end of the tip side shaft 10B and the tip tip 46 to the outside of the balloon catheter 100.

[0034] The tip neck 331 of the balloon 30 is fitted to the base end of the outer periphery of the tip 46. Furthermore, an annular electrode 60 serving as a peripheral electrode is provided on the tip side of the outer periphery of the tip 46. The outer diameter of the annular electrode 60 is, for example, 2.22 mm, and the inner diameter is, for example, 2.08 mm. To fill the gap between the tip neck 331 and the annular electrode 60, a strip electrode 40 of silver (Ag) or similar material with a thickness of approximately 20 μm is formed on the outer periphery of the annular electrode 60 and the balloon 30 by printing or the like. It should be noted that the annular electrode 60 may also be provided on the outer periphery of the pre-formed strip electrode 40. Figure 2 (This example is shown). The tip of the strip electrode 40 is approximately aligned with the tip of the ring electrode 60, located at a position receding from the tip of the tip 46 towards the base. In other words, the tip 46 protrudes towards the tip side of the strip electrode 40 and the ring electrode 60. Thus, even if the tip of the tip 46 comes into contact with the inner wall of a sheath (not shown) that houses the balloon 30 while guiding it to the treatment site, or with internal tissue, damage to the strip electrode 40 and the ring electrode 60 can be prevented.

[0035] An insulating coating 65 with a thickness between 10 μm and 20 μm is applied to the outer periphery of the strip electrode 40, extending from the tip to the tip-side neck 331 and the tip-side cone portion 332. Thus, the strip electrode 40 is configured to apply high frequency to the treatment area on the outer periphery or side of the straight portion 31, which has a stable expanded shape (cylindrical). Furthermore, a ring electrode 60 is circumferentially connected to multiple strip electrodes 40 at the tip portion 33 of the balloon 30. Therefore, multiple strip electrodes 40 can apply substantially the same high frequency voltage and current to the treatment area. Therefore, even if the balloon 30 inserted into the body rotates circumferentially, high frequency can be reliably applied to the treatment area. It should be noted that, although not shown in the figures, a wire from the electrical connector 21 passes through the cable 26, handle portion 20, shaft 10 (sub-shaft 112 described later), and inside the balloon 30 to the tip portion of the balloon conduit 100, connecting to the ring electrode 60 and / or the strip electrode 40. Therefore, the electrical connector 21, which is connected to a high-frequency power source (not shown), can apply a high frequency to the strip electrode 40 on the surface of the balloon 30.

[0036] Also refer to as Figure 2 A magnified view of a part Figure 4 The structure of the base portion 35 of the balloon 30 will be described. Figure 4 In this configuration, the basal neck 351 of the base end portion 35 of the balloon 30 is fitted to the outer periphery of the basal shaft 10A. Here, the outer periphery of the portion of the basal shaft 10A for which the basal neck 351 is fitted is pre-removed by cutting or the like to reduce the thickness of the balloon 30 (e.g., 20 μm). Therefore, with the basal neck 351 fitted to the basal shaft 10A, the height difference between the outer peripheral surface of the basal neck 351 and the outer peripheral surface of the basal shaft 10A, which is closer to the basal side than the basal neck 351, is minimized. Thus, the basal neck 351 and the basal shaft 10A, which are axially adjacent without height difference, are securely fixed by being covered by a tubular resin film 15.

[0037] The outer shaft 10A, serving as the first axis, has an outer cavity that serves as the first chamber through which the inner shaft 41 is inserted. Furthermore, as described above, the inner shaft 41 has an inner cavity 12 through which guide wires, etc., are inserted. (As will be described later...) Figure 6 As shown, the outer cavity within the outer shaft 10A and the inner cavity 12 within the inner shaft 41 represent approximately the same space in cross-section (strictly speaking, the outer cavity 12 is larger than the inner cavity 41 by the thickness of the inner shaft 41 and the amount of clearance between the outer circumferential surface of the inner shaft 41 and the inner circumferential surface of the outer shaft 10A, as described later). Therefore, for convenience, the outer cavity will be labeled with the same reference numerals as the inner cavity 12, and will also be referred to as the outer cavity 12. Furthermore, the outer cavity 12 and the inner cavity 12 will also be collectively referred to as the central cavity 12 or the main cavity 12.

[0038] exist Figure 4In the example, an inner cavity 12 or main cavity 12 is formed at the center of the cross-section of the base end side shaft 10A perpendicular to the axial direction to serve as an inner shaft 41 extending from the device port 24. Figure 1 The internal space of the main cavity 12 or inner shaft 41. In the cross-section of the base end side shaft 10A perpendicular to the axial direction, a plurality of secondary cavities 101L to 112L (hereinafter also referred to as peripheral cavities 101L to 112L) are provided in a circular manner surrounding the outer periphery of the main cavity 12 or inner shaft 41. The plurality of secondary cavities 101L to 112L, which are second cavities, are generally cylindrical spaces formed by a plurality of tubular secondary shafts 101 to 112 (hereinafter also referred to as peripheral shafts 101 to 112) extending along the axial direction as second shafts. It should be noted that in Figure 4 Only seven secondary cavities 106L to 112L and seven secondary shafts 106 to 112 are shown (five secondary cavities 101L to 105L and five secondary shafts 101 to 105 are hidden and cannot be seen).

[0039] Figure 4 Of the seven accessory cavities 106L to 112L shown, five accessory cavities 107L to 111L open into the interior of the balloon 30 at the base end 35, specifically near the boundary between the base-side neck 351 and the base-side cone 352. Furthermore, the bases of the five accessory cavities 107L to 111L are adjacent to the fluid discharge port 23. Figure 1 The balloon 30 is connected to the fluid outlet 23 through five secondary chambers 107L to 111L. A wire 70, whose base is connected to the electrical connector 21, is inserted into the secondary chamber 112L, extending to... Figure 3 The ring electrode 60 and / or strip electrode 40 shown are illustrated. Furthermore, a base terminal is inserted into the secondary cavity 106L for connection with an electrical connector 21. Figure 1 The thermocouple 80, connected to the balloon 30, extends from the base side of the base-side neck 351 (the boundary with the base-side axis 10A) to the outside of the secondary cavity 106L, and extends along the thin-walled balloon 30 (base-side neck 351 and base-side conical portion 352) to the temperature measuring portion in the intermediate portion 31. It should be noted that the secondary cavities 106L, 112L, thermocouple 80, and wire 70 are sealed or protected to prevent the introduction or adhesion of dilatation fluid into the interior of the balloon 30.

[0040] Figure 5 This is a magnified view of a portion of the tip 33 of the balloon 30. Figure 4In the (base end portion 35), seven of the twelve secondary cavities 101L to 112L, namely 106L to 112L, are open or terminated, so only the remaining five secondary cavities 101L to 105L (and half of each of secondary cavities 106L and 112L) extend to the top end portion 33. It should be noted that, as will be described later, all twelve secondary cavities 101L to 112L are arranged at approximately equal intervals in a non-overlapping manner in a cross-sectional view perpendicular to the axial direction.

[0041] The inner shaft 41 is inserted into the outer cavity 12, which serves as the first cavity, of the top side shaft 10B. Figure 5 In the example, an inner cavity 12 or main cavity 12 is formed at the center of the cross-section of the top side shaft 10B perpendicular to the axial direction to serve as an inner shaft 41 extending from the device port 24. Figure 1 The internal space of the main cavity 12 or the inner shaft 41. In the cross section of the top side shaft 10B perpendicular to the axial direction, a plurality of secondary cavities 101L to 105L are provided in a semi-circular manner surrounding the outer periphery of the main cavity 12 or the inner shaft 41. The plurality of secondary cavities 101L to 105L, which are second cavities, are generally cylindrical spaces formed by a plurality of tubular secondary shafts 101 to 105 that extend along the axial direction and serve as second shafts.

[0042] Five secondary cavities 101L to 105L open into the interior of the balloon 30 on the apical side, specifically near the boundary between the apical conical portion 332 and the middle portion 31. Furthermore, the bases of the five secondary cavities 101L to 105L are connected to the fluid supply port 22. Figure 1 The connection is as follows. Therefore, expansion fluid from the fluid supply port 22 can be supplied to the interior of the balloon 30 through the five secondary chambers 101L to 105L. The tip-side shaft 10B, located on the tip side of the opening of the five secondary chambers 101L to 105L, is composed solely of the inner shaft 41. (As per...) Figure 3 As explained, the inner shaft 41 or the tip side shaft 10B extends axially through the interior of the balloon 30, forming, together with the tip tip 46, the opening at the tip of the balloon catheter 100. Thus, the balloon 30, fitted to the tip side of the shaft 10 (which serves as the first shaft), can expand by fluid supplied from the base side of the secondary shafts 101 to 105 (which serve as the second shaft) to the secondary lumens 101L to 105L (which serve as the second lumen).

[0043] Next, refer to Figure 6 The relationship between the central main cavity 12 and the twelve peripheral secondary cavities 101L to 112L in the cross section of the outer shaft 10 perpendicular to the axial direction is explained. Figure 6 The cross-section of the base end side shaft 10A of the outer shaft 10, where the secondary cavities 101L to 112L are not terminated, for example, represents... Figure 4A cross-section of the basal end (boundary to the basal side axis 10A) of the basal neck 351 of the medium-sized balloon 30. It should be noted that the tubular resin coating 15 covering the periphery of the basal side axis 10A is omitted from the illustration.

[0044] Twelve secondary cavities 101L to 112L are arranged in a circular shape surrounding the central main cavity 12. Each secondary cavity 101L to 112L is along the axial direction (perpendicular to...). Figure 6 The tubular secondary shafts 101-112 extend in the direction of the paper and are generally cylindrical spaces inside. In the illustrated example, all secondary cavities 101L-112L have approximately the same diameter, cross-sectional area, and shape, but they may also differ from one another. Furthermore, the diameter and cross-sectional area of ​​each secondary cavity 101L-112L are smaller than the main cavity 12, but it is also possible that at least one secondary cavity 101L-112L has a larger diameter and cross-sectional area than the main cavity 12. The twelve secondary cavities 101L-112L and the twelve secondary shafts 101-112 are arranged at approximately equal intervals along the circumferential direction centered on the central axis of the main cavity 12 or the outer shaft 10. That is, Figure 6 The circumferential spacing of the twelve secondary cavities 101L to 112L and the twelve secondary shafts 101 to 112 in the cross-section is approximately constant. It should be noted that "approximately constant spacing" means that the difference between any two spacings is less than 10% of the average of all spacings. Here, the secondary shafts 101 to 112 constituting each secondary cavity 101L to 112L are... Figure 6 The cross sections are not externally connected. As will be described later, the first component that enters the inner side through the gap between each of the secondary shafts 101 to 112 constitutes part of the inner circumferential surface of the outer shaft 10, thereby forming the main cavity 12 as shown in the figure.

[0045] Each of the secondary shafts 101 to 112, serving as the second shaft, is composed of a second member with a lower frictional coefficient than the first member constituting the inner circumferential surface of the outer shaft 10, which serves as the first shaft. This second member, together with the main component of the outer shaft 10 (i.e., the first member), forms the inner circumferential surface defining the outer cavity 12 or main cavity 12, which serves as the first cavity. Here, the main component is a member constituting more than half the volume of the outer shaft 10. The first member (the main component of the outer shaft 10) is made of, for example, nylon or urethane, and the second member (each of the secondary shafts 101 to 112) is made of, for example, a fluoropolymer such as polytetrafluoroethylene (PTFE) or perfluoroalkoxy resin (PFA). The coefficient of kinetic friction of the second member is preferably between 0.02 and 0.50, and more preferably between 0.03 and 0.09.

[0046] A portion of the outer peripheral surface of each of the sub-shafts 101-112 protrudes into the outer cavity 12 or the main cavity 12 from a portion of the inner peripheral surface of the outer shaft 10. In particular, in the illustrated example, a second member, such as fluoropolymer, constituting the outer peripheral surface of each of the sub-shafts 101-112, protrudes into the main cavity 12 from the first member constituting the inner peripheral surface of the outer shaft 10. With these configurations, the inner shaft 41 smoothly inserts into the outer cavity 12 or the main cavity 12 while contacting the low-friction second member (each of the sub-shafts 101-112). Furthermore, a first member with higher friction than the second member is provided between a plurality of low-friction second members (each of the sub-shafts 101-112) arranged circumferentially along the inner peripheral surface of the outer shaft 10, thus preventing the smoothness of the outer cavity 12 or the main cavity 12 relative to the inner shaft 41 from becoming excessive. Here, the proportion of the low-friction second components (each of the sub-shafts 101 to 112) in the outer periphery of the main cavity 12 is arbitrary, but it is preferably set to 30% or more for improving smoothness. In this case, the proportion of the high-friction first components (the main constituent components of the outer shaft 10) in the outer periphery of the main cavity 12 is less than 70%. Furthermore, for improving the smoothness of the main cavity 12, it is preferable to maximize the proportion of the second components, but considering the… Figure 8 The stability and efficiency of manufacturing, which will be discussed later, are actually set at an upper limit of around 50%.

[0047] In conventional catheters as shown in Patent Document 1, multiple secondary shafts constituting multiple secondary lumens are arranged around the main shaft constituting the main lumen, but... Figure 6 There is no need to set up a separate main shaft to form the outer cavity 12 or the main cavity 12, so the outer cavity 12 or the main cavity 12 can be larger than before. Alternatively, multiple secondary shafts can be placed close to the outer cavity 12 or the main cavity 12, which is the same size as before, so the diameter of the outer shaft 10 can be smaller than before.

[0048] As in relative Figure 4 After removing the balloon 30, inner shaft 41, wire 70, thermocouple 80, etc. Figure 7 As schematically shown, the low-friction second member exposed into the outer cavity 12 or the main cavity 12 (in) Figure 7 The seven secondary shafts (101-106, 112) extend axially, thus smoothly guiding the inner shaft 41 to be inserted axially into the outer cavity 12 or the main cavity 12.

[0049] Figure 8 Schematic representation Figure 6An example of a manufacturing method for the structure is provided. The tubular or cylindrical first cavity forming member 42 has an outer peripheral surface corresponding to the outer peripheral surface of the outer cavity 12 or the inner peripheral surface of the outer shaft 10. Twelve sub-shafts 101-112 are arranged at approximately equal intervals on the outer periphery of the first cavity forming member 42. Alternatively, recesses for fitting the sides of each sub-shaft 101-112 may be provided on the outer periphery of the first cavity forming member 42 to allow for proper arrangement of each sub-shaft 101-112. It should be noted that the material of the first cavity forming member 42 is arbitrary, for example, fluoropolymer.

[0050] The first cavity forming member 42 and the twelve sub-shafts 101-112 are covered from the outside by a heat-shrink tube 43. In this state, granules of thermoplastic resin such as nylon or urethane, which forms the main component of the outer shaft 10, are inserted between the inner circumference of the heat-shrink tube 43 and the outer circumference of the first cavity forming member 42 and the twelve sub-shafts 101-112, and then heated. The molten thermoplastic resin enters the inner side through the gaps between each sub-shaft 101-112, forming the inner circumferential surface of the outer shaft 10 together with the outer circumferential surface of each sub-shaft 101-112. Furthermore, the heat-shrink tube 43, which shrinks during heating, forms the outer circumferential surface of the outer shaft 10. After cooling, the first cavity forming member 42 and the heat-shrink tube 43 are removed, realizing... Figure 6 The composition of.

[0051] The present disclosure has been described above based on embodiments. The embodiments are examples, and those skilled in the art will understand that various modifications can be made to the combination of these constituent elements and processing procedures, and such modifications are also within the scope of the present disclosure.

[0052] In the above embodiment, the low-friction second member exposed to the first cavity (outer cavity 12 or main cavity 12) in a portion of the inner circumferential surface of the first shaft (outer shaft 10) is formed by the outer circumferential surface of the secondary shafts 101-112, which serve as the second shaft. However, the configuration of the low-friction second member is not limited to this. For example, it could also be as follows: Figure 9 As schematically shown, one or more low-friction second members 113-116 are arranged circumferentially on the inner circumferential surface of the high-friction outer shaft 10. In this example, the second members 113-116, together with the main constituent member of the outer shaft 10, namely the first member, form the inner circumferential surface defining the outer cavity 12. It should be noted that in Figure 9 In the middle, the following was omitted. Figure 6 The diagram shows the inner shaft 41. Furthermore, the second members 113-116 may extend axially from the base end to the top end of the shaft 10. Alternatively, the second members 113-116 may be either dispersed axially or formed in a spiral shape around the axial direction instead of extending axially.

[0053] Explanation of reference numerals in the attached figures

[0054] 10: Outer shaft;

[0055] 10A: Base end side shaft;

[0056] 10B: Top side shaft;

[0057] 12: Main cavity;

[0058] 24: Device port;

[0059] 30: Balloon;

[0060] 41: Inner shaft;

[0061] 100: Balloon catheter;

[0062] 101~112: Secondary shaft;

[0063] 101L~112L: Secondary cavity;

[0064] 113~116: Second component.

Claims

1. A catheter, wherein, The catheter has: A first shaft, for insertion into the body, has a first cavity extending axially from the base side toward the tip side; and The second component, together with the first component which is a main component of the first shaft, forms the inner peripheral surface defining the first cavity. The frictionality of the second component is lower than that of the first component. The catheter further comprises: a second shaft having a second lumen extending along the axial direction, the second shaft being formed by the second component. A portion of the outer peripheral surface of the second shaft, together with the first component, forms the inner peripheral surface that defines the first cavity.

2. The catheter according to claim 1, wherein, The second component extends along the said axial direction.

3. The catheter according to claim 2, wherein, The second member extends along the axial direction from the base end to the top end of the first shaft.

4. The catheter according to any one of claims 1 to 3, wherein, A plurality of the second components are provided along the circumferential direction of the inner circumferential surface.

5. The catheter according to claim 4, wherein, The circumferential spacing of the plurality of second components is approximately constant.

6. The catheter according to any one of claims 1 to 3, wherein, The second component protrudes from the first component into the first cavity.

7. The catheter according to any one of claims 1 to 3, wherein, The second component is made of fluororesin.

8. The catheter according to claim 1, wherein, The catheter further comprises: a balloon, fitted to the top end of the first shaft, capable of being expanded by fluid supplied from the base end of the second shaft into the second lumen.

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