Catheter

Abstract

To provide a catheter capable of suppressing damage of operating wires or a tubular body due to expansion of the tubular body and suitable for shortening the length in a major axis direction of an operating part.SOLUTION: A catheter includes: a tubular body 20 to be inserted into a biological lumen; a plurality of operating wires that are inserted into the tubular body and whose tips are respectively connected to a distal portion of the tubular body; an operating-part body 51 provided in a proximal portion of the tubular body; an operating member 53 to which the base ends of the operating wires are fixed, that is rotatably attached to the operating-part body and that applies traction force to the operating wires by rotation to bend the distal portion of the tubular body; and a plurality of adjustment parts 54A and 54B provided in the operating-part body corresponding to each operating wire and forming deflection margins of the operating wires in response to expansion of the tubular body. Each of the adjustment parts has a plurality of pulleys (61A, 62A and 61B, 62B) whose distance from each other can be changed, and the length of the operating wires suspended between the pulleys can be freely adjusted.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a catheter. [Background technology]

[0002] Conventionally, catheters have been provided that can operate the distal portion of a tubular body inserted into a biological lumen in response to operation of an operation portion provided in the proximal portion. For example, Patent Document 1 discloses a surgical instrument in which an operation portion pulls an operation wire arranged along the tubular body to open or close an end tool arranged at the tip of the tubular body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-154154 Summary of the Invention [Problem to be solved by the invention]

[0004] The tubular body of a catheter containing an operating wire has a larger coefficient of linear expansion and a larger coefficient of swelling than the operating wire. Therefore, if the thermal or temperature environment of the catheter changes after assembly and molding, the expansion of the tubular body can place a large load on the operating wire or the tubular body, potentially causing breakage of the operating wire or plastic bending of the tubular body. Therefore, the operating section of the catheter needs to be configured to prevent damage to the operating wire or the tubular body due to expansion of the tubular body.

[0005] On the other hand, one application of this type of catheter is to perform a procedure by inserting a smaller-diameter catheter into the other catheter in a nested manner. When inserting a catheter into an outer catheter, the smaller-diameter catheter needs to protrude from the tip of the outer catheter during the procedure. Therefore, with regard to the outer catheter into which the smaller-diameter catheter is inserted, there has been a strong demand in recent years to shorten the longitudinal length of the operating section provided in the proximal portion while maintaining the longitudinal length of the tubular main body so that the smaller-diameter catheter can protrude from the tip of the outer catheter.

[0006] Therefore, the present invention has been made in consideration of the above situation, and aims to provide a catheter that can suppress damage to the operating wire or tubular body due to expansion of the tubular body, and is suitable for shortening the longitudinal length of the operating section. [Means for solving the problem]

[0007] A catheter of one embodiment comprises a tubular body to be inserted into a biological lumen, a plurality of operating wires inserted through the tubular body and each having a tip connected to a distal portion of the tubular body, a control unit main body provided in the proximal portion of the tubular body, an operating member to which the base ends of the operating wires are fixed and which is rotatably attached to the control unit main body and which, when rotated, applies traction to the operating wires to bend the distal portion of the tubular body, and a plurality of adjustment units provided in the control unit main body corresponding to each operating wire and which form a flexure allowance of the operating wire in response to expansion of the tubular body. Each adjustment unit has a plurality of pulleys whose distance from each other can be changed, and the length of the operating wire suspended between the pulleys can be freely adjusted. [Effects of the Invention]

[0008] According to one aspect, it is possible to provide a catheter that can suppress damage to the operating wire or the tubular body due to expansion of the tubular body, and is suitable for shortening the length of the operating section in the longitudinal direction. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing an example of a catheter according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the catheter taken along line AA. [Figure 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. 2. [Figure 4] FIG. 2(a) is a perspective view showing the appearance of the operation unit, and FIG. 2(b) is a perspective view showing the internal structure of the operation unit. [Figure 5] FIG. 2 is a plan view showing the internal structure of the operation unit. [Figure 6] FIG. 6 is a cross-sectional view taken along line CC in FIG. 5. [Figure 7] FIG. 2(a) is a plan view of the adjustment unit and the locking mechanism, and FIG. 2(b) is a side view of the adjustment unit and the locking mechanism. [Figure 8] FIG. 7(b) is a cross-sectional view taken along line EE in FIG. [Figure 9] 1A is a plan view showing the arrangement of one of the operating wires in the adjustment section, and FIG. 1B is a side view showing the arrangement of one of the operating wires in the adjustment section. [Figure 10] 10A and 10B are diagrams illustrating an example of operation of a first locking part of the locking mechanism. [Figure 11] FIG. 2 is a diagram illustrating a schematic configuration of an adjustment unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] An example of the configuration of a catheter according to this embodiment will be described below with reference to the drawings. Note that the shapes, dimensions, etc. of each part in the drawings are shown schematically and do not represent the actual shapes, dimensions, etc. In the following description, the part of the catheter that is farther from the operator will be referred to as the distal part, and the distal part in the drawings will be indicated by the symbol DE as appropriate. In addition, the part of the catheter that is closer to the operator will be referred to as the proximal part, and the proximal part in the drawings will be indicated by the symbol PE as appropriate.

[0011] Fig. 1 is a side view showing an example of a catheter 10 of this embodiment. Fig. 2 is an enlarged cross-sectional view of the portion of the catheter 10 taken along line AA. Fig. 3 is a cross-sectional view of the portion of the catheter 10 taken along line BB in Fig. 2.

[0012] The catheter 10 of this embodiment includes a sheath 20, which is an example of a tubular body, a plurality of operating wires 30 inserted through the sheath 20 along the longitudinal direction of the sheath 20, and a control section 50 provided on the proximal end side of the sheath 20 and connected to the operating wires 30. The catheter 10 of the first embodiment is capable of bending the distal portion of the sheath 20 by individually pulling and operating the operating wires 30 with the control section 50.

[0013] The sheath 20 is a flexible, long tubular body that is inserted into a body lumen either through an endoscope or directly. The outer diameter of the sheath 20 in this embodiment is large enough to allow insertion into blood vessels such as the celiac artery, and peripheral blood vessels such as the hepatic artery and branches of the internal carotid artery.

[0014] As shown in FIGS. 2 and 3, the sheath 20 has an inner layer 21, a first reinforcing layer 22, an outer layer 23, an operating wire 30, and a marker 40.

[0015] The inner layer 21 of the sheath 20 is formed in a tubular shape from a biocompatible resin material. The inner layer 21 defines a hollow tubular main lumen 21a therein through which a medicinal solution, a contrast agent, etc. are passed. The inner layer 21 can be manufactured, for example, by forming a tubular coating of the inner layer 21 from a resin material on the surface of a cylindrical main core wire (not shown), and then pulling the main core wire out of the coating. Note that another catheter having a smaller diameter than the inner diameter of the inner layer 21 may be inserted into the main lumen 21a from the proximal end in a nested manner.

[0016] 2, the cross-sectional shape of the inner layer 21 in a direction perpendicular to the longitudinal axis direction is circular, and the inner layer 21 has a substantially uniform thickness in the circumferential direction. The thickness of the inner layer 21 may be uniform along the longitudinal axis direction, or may vary depending on the position along the longitudinal axis of the sheath 20. For example, the inner layer 21 may be formed so that the diameter of the main lumen 21a is tapered, continuously increasing from the distal portion to the proximal portion.

[0017] As an example, a fluorine-based thermoplastic polymer material can be used as the material for the inner layer 21. Specifically, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), perfluoroalkoxy fluororesin (PFA), etc. can be used as the material for the inner layer 21. By using a fluorine-based resin for the inner layer 21, the deliverability when supplying a contrast agent, a medicinal solution, etc. to an affected area through the main lumen 21a of the catheter 10 is improved.

[0018] The first reinforcing layer 22 is disposed concentrically on the outer periphery of the inner layer 21 and serves to reinforce the inner layer 21 from the outside while maintaining the flexibility of the sheath 20. The first reinforcing layer 22 is formed into a tubular shape, for example, by winding a wire around the inner layer 21 or by weaving wires into a mesh shape.

[0019] Wires that can be used for the first reinforcing layer 22 include thin metal wires made of tungsten (W), stainless steel (SUS), nickel-titanium alloy, steel, titanium, copper, titanium alloy, copper alloy, etc., as well as thin polymer fiber wires made of polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), etc., which have higher shear strength than the inner layer 21 and the outer layer 23. The cross-sectional shape of the wire that can be used for the first reinforcing layer 22 is not particularly limited, and may be a round wire or a flat wire.

[0020] The outer layer 23 is made of a biocompatible resin material and is formed integrally with the inner layer 21 so as to form a tubular shape on the outer peripheral side of the inner layer 21, and has a substantially uniform thickness in the circumferential direction. The outer layer 23 is thicker in the radial direction than the inner layer 21, and encloses the first reinforcing layer 22 and constitutes the main thick portion of the sheath 20. In addition, a hydrophilic coating 24 is formed on the outer peripheral side of the outer layer 23 using a material such as polyvinyl alcohol (PVA) or polyvinylpyrrolidone.

[0021] The outer layer 23 is formed of the same or different resin material as the inner layer 21. Although not particularly limited, a wide variety of thermoplastic polymers can be used as the material for the outer layer 23. For example, in addition to the above-mentioned PI, PAI, and PET, the outer layer 23 can be made of polyethylene (PE), polyamide (PA), nylon elastomer, polyurethane (PU), ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVA), or polypropylene (PP). Note that the material for the outer layer 23 may be mixed with an inorganic filler such as barium sulfate or bismuth subcarbonate to improve X-ray contrast.

[0022] Furthermore, the outer layer 23 has a plurality of sublumens 25a and a second reinforcing layer 29 on the outer side of the inner layer 21 and the first reinforcing layer 22.

[0023] The sub-lumens 25a are tubular spaces with a smaller diameter than the main lumen 21a, and a plurality of them are arranged around the main lumen 21a at predetermined intervals in the circumferential direction of the outer layer 23. For example, the sub-lumens 25a are arranged in parallel with each other so that their longitudinal axes are aligned with the longitudinal axis direction of the main lumen 21a. Figures 2 and 3 show an example in which two sub-lumens 25a are arranged 180 degrees apart in the circumferential direction of the outer layer 23.

[0024] The number and arrangement of sub-lumens 25a in outer layer 23 are not limited to the above example. For example, three or more sub-lumens 25a may be formed. Furthermore, sub-lumens 25a may extend at an angle relative to main lumen 21a so as to include a longitudinal component and a circumferential component.

[0025] Each sub-lumen 25a is formed by a hollow tube 25 embedded in the outer layer 23. The hollow tube 25 is arranged along the main lumen 21a, and as shown in FIG. 3, its distal end faces the marker 40, and its proximal end is introduced into the operating section 50. An operating wire 30 is slidably inserted into the hollow tube 25 along the longitudinal axis of the sheath 20. Note that, because the hollow tube 25 through which the operating wire 30 is inserted is arranged outside the first reinforcing layer 22, the main lumen 21a is protected by the first reinforcing layer 22 against sliding of the operating wire 30.

[0026] The hollow tube 25 is formed, for example, from the same or different resin material as the inner layer 21. As an example, the hollow tube 25 may be made of a fluorine-based polymer material such as PTFE or PVDF, polyether ether ketone (PEEK), polysulfone (PSF), high density polyethylene (HDPE), polyester, or the like, from the viewpoint of sliding property with the operating wire 30.

[0027] The inner diameter of the sub-lumen 25a is larger than the outer diameter of the operating wire 30 to allow the operating wire 30 to be inserted and to slide in the longitudinal direction of the operating wire 30. Note that, similar to the inner layer 21, the hollow tube 25 of the sub-lumen 25a can also be manufactured by forming a tubular coating of a resin material on the surface of a cylindrical core wire (not shown) and then pulling the core wire out of the coating.

[0028] The second reinforcing layer 29 is disposed outside the main lumen 21a and the plurality of sub-lumens 25a, and externally covers the inner layer 21 and the plurality of hollow tubes 25, which are covered with the first reinforcing layer 22. The second reinforcing layer 29 prevents the operating wire 30 disposed in the sub-lumen 25a from being exposed to the outside of the sheath 20, and also functions to position and hold the plurality of hollow tubes 25 relative to the inner layer 21 during the manufacture of the sheath 20.

[0029] The second reinforcing layer 29 is formed, for example, of reinforcing wire 29a wound helically from the outside of the inner layer 21 covered with the first reinforcing layer 22 and the plurality of hollow tubes 25, and is arranged along the longitudinal axis direction of the sheath 20. The reinforcing wire 29a of the second reinforcing layer 29 can be made of, for example, the materials exemplified for the first reinforcing layer 22. As an example, in this embodiment, flat reinforcing wire 29a is illustrated, but the wire of the first reinforcing layer 22 and the reinforcing wire 29a may have the same configuration or different configurations.

[0030] The operating wires 30 are linear members extending in the longitudinal direction of the sheath 20, and one operating wire is disposed in each sub-lumen 25a across the main lumen 21a. The distal end of each operating wire 30 is fixed to a marker 40, and the proximal end of each operating wire 30 is connected to an operating section 50. Furthermore, each operating wire 30 can slide in the longitudinal direction within the sub-lumen 25a by being pulled by the operating section 50.

[0031] Examples of materials that can be used for the operating wire 30 include low carbon steel (piano wire), SUS, steel wire with a corrosion-resistant coating, titanium or a titanium alloy, and tungsten. The operating wire 30 may be made of a single metal wire or may be a twisted wire of multiple thin metal wires.

[0032] The marker 40 is a ring-shaped member provided at the tip of the sheath 20, and functions as an indicator when observing the tip of the sheath 20 from the outside using an X-ray image. The marker 40 is made of a material that has X-ray contrast properties, such as platinum (Pr), platinum iridium (PrIr), or tungsten.

[0033] 3, the marker 40 is fixed to the outer periphery of the inner layer 21 and the first reinforcing layer 22 at the tip of the sheath 20, and is covered from the outside by the outer layer 23. The tip of each operating wire 30 is fixed to the marker 40. The manner in which the operating wire 30 is fixed to the marker 40 is not particularly limited, and may be any of solder bonding, heat fusion bonding, adhesion with an adhesive, mechanical engagement between the operating wire 30 and the marker 40, etc.

[0034] Here, the specifications of the catheter 10 will be exemplified. The diameter of the main lumen 21a is 400 μm to 950 μm (including upper and lower limits; the same applies below), the thickness of the inner layer 21 is 5 μm to 30 μm, and the thickness of the outer layer 23 is 10 μm to 200 μm. The thickness of the sub-lumen 25a is thinner than that of the inner layer 21 and is 1 μm to 10 μm. The inner diameter of the first reinforcing layer 22 is 410 μm to 1,010 μm, and the outer diameter of the first reinforcing layer 22 is 450 μm to 1,070 μm. The inner diameter of the second reinforcing layer 29 is 560 μm to 1,070 μm, and the outer diameter of the second reinforcing layer 29 is 600 μm to 1,090 μm. The inner diameter of the marker 40 is 450 μm to 1,070 μm, and the outer diameter of the marker 40 is 490 μm to 1,090 μm. The radius (distance) from the axis of catheter 10 to the center of sublumen 25a is 300 μm to 600 μm, the inner diameter (diameter) of sublumen 25a is 30 μm to 100 μm, and the thickness of operating wire 30 is 25 μm to 80 μm. The diameter of the sheath 20 is 700 μm to 1,135 μm, that is, the outer diameter is less than 1.14 mm, and the sheath 20 constitutes a microcatheter that can be inserted into peripheral blood vessels.

[0035] The linear expansion coefficient of the sheath 20 is larger than the linear expansion coefficient of the operating wire 30. For example, the linear expansion coefficient of the sheath 20 is 100 ppm / K or more and 300 ppm / K or less, and the linear expansion coefficient of the operating wire 30 is 10 ppm / K or more and 30 ppm / K or less. Furthermore, the swelling coefficient of the sheath 20 is greater than that of the operating wire 30. Here, the linear expansion coefficient or swelling coefficient of the sheath 20 refers to the linear expansion coefficient or swelling coefficient when the laminated structure of the sheath 20 is considered as a whole. That is, the linear expansion coefficient or swelling coefficient of the sheath 20 refers to the combined linear expansion coefficient or swelling coefficient of the composite structure of the inner layer 21, outer layer 23, first reinforcing layer 22, second reinforcing layer 29, sublumen 25a, and other components (excluding the operating wire 30) that are closely adhered to one another and integrated. The linear expansion coefficient or swelling coefficient of the sheath 20 can be roughly calculated by multiplying the linear expansion coefficient or swelling coefficient of each of the above components by their respective Young's moduli and area ratios in the cross-sectional area.

[0036] In this embodiment, as described above, the linear expansion coefficient and swelling coefficient of the sheath 20 are larger than those of the operating wire 30. Therefore, excessive tension may be applied to the operating wire 30 under various environments after assembly and packaging of the catheter 10, such as during heat sterilization or during summer transportation. In contrast, the catheter 10 of this embodiment can release the excessive tension by operating the operating unit 50. Hereinafter, examples of the configuration of the operating unit 50 will be described with reference to Figures 4 to 10.

[0037] FIG. 4(a) is a perspective view showing the appearance of the operating unit 50, and FIG. 4(b) is a perspective view showing the internal structure of the operating unit 50. FIG. 5 is a plan view showing the internal structure of the operating unit 50. FIG. 6 is a cross-sectional view taken along line CC in FIG. 5. FIG. 7(a) is a plan view of the adjustment units 54A and 54B and the locking mechanism 55, and FIG. 7(b) is a side view of the adjustment units 54A and 54B and the locking mechanism 55. FIG. 8 is a cross-sectional view taken along line EE in FIG. 7(a). FIG. 9(a) is a plan view showing the arrangement of one operating wire 30 in the adjustment unit 54A, and FIG. 9(b) is a side view showing the arrangement of one operating wire 30 in the adjustment unit 54A. FIG. 10 is a diagram showing an example of the operation of the first locking unit 72 of the locking mechanism 55. Note that the operating wire 30 has been omitted from FIGS. 4(b) to 8 for ease of understanding.

[0038] The operation unit 50 includes an operation unit main body 51, a hub connector 52, a dial 53, a plurality of adjustment units 54A and 54B, and a locking mechanism 55.

[0039] The control unit main body 51 is a housing provided in the proximal portion of the sheath 20 and is held by the hand of an operator who operates the catheter 10. The proximal portion of the sheath 20 is protected by a tubular protector 56 and is introduced into the control unit main body 51.

[0040] Furthermore, operation unit main body 51 has a pair of cam grooves consisting of first cam groove 57A and second cam groove 57B, and a pair of wire guides 58. The pair of cam grooves (57A, 57B) and the pair of wire guides 58 are arranged line-symmetrically within operation unit main body 51 with sheath 20 at the center. First cam groove 57A and second cam groove 57B are both arc-shaped and arranged such that the distance between them increases from the distal end to the proximal end. Furthermore, wire guide 58 is arranged between adjustment units 54A, 54B and dial 53 in the longitudinal direction, and operation wires 30 extending from the adjustment units to dial 53 are hung on wire guide 58.

[0041] The hub connector 52 is attached to the proximal end side of the operation unit main body 51, and its tip is in communication with the main lumen 21a of the sheath 20. A syringe (not shown) for injecting a medicinal solution or the like can be connected to the hub connector 52. By injecting a medicinal solution or the like from the syringe into the hub connector 52, the medicinal solution or the like is supplied into the body lumen via the main lumen 21a of the sheath 20. When another catheter with a smaller diameter is inserted nested within the catheter 10, the other catheter is inserted into the main lumen 21a from the proximal end side of the hub connector 52.

[0042] Dial 53 is an example of an operating member, and is a disk-shaped member that can be rotated around a rotation axis along the longitudinal direction of sheath 20. A cylindrical shaft 59 extending along the longitudinal direction of sheath 20 is inserted into the axial center of dial 53, and dial 53 is supported relative to shaft 59 so as to be rotatable in the circumferential direction of shaft 59. In addition, sheath 20 is inserted inside shaft 59.

[0043] As a result, the rotation axis of the dial 53 is arranged parallel to the longitudinal axis direction of the sheath 20, and the dial 53 is attached to the operating unit main body 51 so that its rotation axis is inclined with respect to the radial direction perpendicular to the longitudinal axis direction of the sheath 20.

[0044] Furthermore, the base ends of two operating wires 30 that are pulled out from the sheath 20 on the base end side of the dial 53 are fixed to the dial 53. Each operating wire 30 is connected to one circumferential side and the other circumferential side of the dial 53, separated by a shaft 59. Therefore, the dial 53 can apply a traction force to each operating wire 30 individually by rotating it to one circumferential side and the other circumferential side.

[0045] Rotation of the dial 53 in the operating unit 50 winds up one of the operating wires 30, causing the operating wire 30 to slide in the longitudinal direction. For example, when the dial 53 is rotated counterclockwise as shown in FIG. 1(b), one of the operating wires 30 in the sheath 20 slides and is pulled toward the base end, while the other operating wire 30 is relaxed. As a result, a tensile force is applied to one of the operating wires 30, which is eccentric from the axis of the sheath 20, and the distal portion of the sheath 20 bends toward the side of one of the operating wires 30 (downward in the figure).

[0046] 1(c), for example, when the dial 53 is rotated clockwise, the other operating wire 30 of the sheath 20 slides and is pulled toward the base end, and one operating wire 30 is relaxed. As a result, a tensile force is applied to the other operating wire 30, which is eccentric with respect to the axis of the sheath 20, and the distal portion of the sheath 20 is bent toward the other operating wire 30 (upward in the figure). In this way, the distal portion of the sheath 20 can be bent in accordance with the rotation of the dial 53 in the operating unit 50.

[0047] The adjustment units 54A and 54B are elements that form a flexure allowance for the operating wire 30 in response to the expansion of the sheath 20, and two of them are provided in the proximal portion of the dial 53 inside the operating unit main body 51. One adjustment unit 54A and one adjustment unit 54B are provided corresponding to each operating wire 30, and are arranged in the operating unit main body 51 line-symmetrically with the sheath 20 as the center.

[0048] The adjustment unit 54A, which is located on the lower side in Fig. 5, is capable of freely adjusting the length of one operating wire 30 drawn out to the lower side in Fig. 5 within the adjustment unit 54A. The adjustment unit 54A has a first pulley 61A and a second pulley 62A, on which one operating wire 30 is suspended and whose distance from each other is changeable.

[0049] The first pulley 61A of the adjustment unit 54A is disposed on the base end side of the operation unit body 51, and the position of the axis is fixed on the operation unit body 51. The first pulleys 61A are attached in three layers in parallel to the axis.

[0050] The second pulley 62A of the adjustment unit 54A is disposed closer to the tip end than the first pulley 61A in the operation unit body 51, and is movably supported within the operation unit body 51. The second pulleys 62A are attached in parallel, stacked on top of each other, at their respective shaft centers. The shaft center of the second pulley 62A is movably supported by the first arm 63A, and the end is guided by the first cam groove 57A of the operation unit body 51.

[0051] Here, the diameter D of the first pulley 61A and the second pulley 62A is a value that satisfies D / d>40 when the diameter of the operating wire 30 is d. When the above relationship is satisfied, the diameters of the first pulley 61A and the second pulley 62A are sufficiently large relative to the diameter of the operating wire 30, and the contact area between the first pulley 61A or the second pulley 62A and the operating wire 30 is ensured. This makes it difficult for excessive stress to be applied to the operating wire 30 that is in contact with the first pulley 61A or the second pulley 62A, and prevents the operating wire 30 from breaking at the adjustment part 54A.

[0052] The first arm 63A is a member that extends from the axis of a first pulley 61B (described later) of the adjustment unit 54B to the adjustment unit 54A in a plan view, straddling the sheath 20. The first arm 63A rotates around the axis of the first pulley 61B of the adjustment unit 54B within the operation unit main body 51. The first arm 63A also has a protrusion 63A1 at a position near the sheath 20 that receives a first pin 72a (described later) of the locking mechanism 55.

[0053] The axis of second pulley 62A supported by first arm 63A is movable within operation unit main body 51 along first cam groove 57A. Therefore, the first pulley 61A and second pulley 62A of adjustment unit 54A can change the distance between their axes in the perpendicular direction. Note that first cam groove 57A forms an arc centered on first pulley 61B of adjustment unit 54B and is inclined from the distal end to the proximal end. Therefore, second pulley 62A moves in a direction intersecting the longitudinal axis of sheath 20 relative to first pulley 61A.

[0054] Furthermore, the adjustment unit 54B, which is arranged on the upper side in Fig. 5, can freely adjust the length of the other operating wire 30 drawn out on the upper side in Fig. 5 within the adjustment unit 54B. The adjustment unit 54B has a first pulley 61B and a second pulley 62B on which the other operating wire 30 is suspended and whose distance from each other is changeable.

[0055] The first pulley 61B of the adjustment unit 54B is disposed on the base end side of the operation unit body 51, and the position of the axis is fixed on the operation unit body 51. The first pulleys 61B are attached in three layers in parallel to the axis.

[0056] The second pulley 62B of the adjustment unit 54B is disposed closer to the tip end than the first pulley 61B in the operation unit body 51, and is movably supported within the operation unit body 51. The second pulleys 62B are attached in parallel, stacked on top of each other, at their respective shaft centers. The shaft centers of the second pulleys 62B are movably supported by the second arm 63B, and the ends are guided by the second cam groove 57B of the operation unit body 51.

[0057] The relationship between the diameter D of the first pulley and the second pulley in the adjustment unit 54B and the diameter d of the operating wire 30 is a value that satisfies D / d>40 for the same reason as in the adjustment unit 54A.

[0058] The second arm 63B is a member that extends from the axis of the first pulley 61A of the adjustment unit 54A across the sheath 20 to the adjustment unit 54B in a plan view. The second arm 63B is disposed offset from the first arm 63A in the height direction (the up-and-down direction in FIG. 7(b)) and intersects with the first arm 63A in a plan view. The second arm 63B rotates within the operation unit main body 51 around the axis of the first pulley 61A of the adjustment unit 54A. The second arm 63B also has a protrusion 63B1 near the sheath 20 that receives a second pin 73a (described later) of the locking mechanism 55.

[0059] The axis of second pulley 62B supported by second arm 63B is movable within operation unit main body 51 along second cam groove 57B. Therefore, first pulley 61B and second pulley 62B of adjustment unit 54B can change the perpendicular distance between their axes independently of adjustment unit 54A. Note that second cam groove 57B forms an arc centered on first pulley 61A of adjustment unit 54A and is inclined from the distal end to the proximal end. Therefore, second pulley 62B moves relative to first pulley 61B in a direction intersecting the longitudinal axis of sheath 20.

[0060] The arrangement of the operating lines 30 in the operating unit 50 will be described below with reference to Fig. 9. Note that the arrangement of one operating line 30 and the arrangement of the other operating line 30 in the operating unit 50 are almost the same, so in the following example, one operating line 30 will be described, and a duplicated explanation of the other operating line 30 will be omitted.

[0061] One operating wire 30 drawn out from the sheath 20 is hung on the first stage of the first pulley 61A of the adjustment unit 54A (the top stage of the first pulley 61A in FIG. 9(b)), folded back toward the tip, and hung on the first stage of the second pulley 62A of the adjustment unit 54A (the top stage of the second pulley 62A in FIG. 9(b)). Thereafter, one operating wire 30 is hung on the second stage of the first pulley 61A, the second stage of the second pulley 62A, and the third stage of the first pulley 61A, successively, and hung so as to make multiple turns around the first pulley 61A and the second pulley 62A. Then, one operating wire 30 extending from the third stage of the first pulley 61A is fixed to the dial 53 via a wire guide 58.

[0062] That is, one operating wire 30 in adjustment unit 54A is alternately looped over first pulley 61A and second pulley 62A. The number of times one operating wire 30 is looped over first pulley 61A is greater than the number of times one operating wire 30 is looped over second pulley 62A. As a result, one operating wire 30 passes through first pulley 61A, which is a fixed pulley, at the point where it is pulled from catheter 10 into adjustment unit 54A and at the point where it is pulled out from adjustment unit 54A toward dial 53, thereby stabilizing the operation of one operating wire 30 in adjustment unit 54A.

[0063] Next, the locking mechanism 55 will be described. The locking mechanism 55 is an element that switches between a first state in which the second pulleys 62A, 62B of the adjustment units 54A, 54B are movable, and a second state in which the movement of the second pulleys 62A, 62B is restricted. The locking mechanism 55 has a casing 71, a first locking unit 72 corresponding to the adjustment unit 54A, a second locking unit 73 corresponding to the adjustment unit 54B, a locking switch 74, and a latch unit 60 provided on the operation unit main body 51.

[0064] The casing 71 of the locking mechanism 55 is disposed on the proximal end side of the first arm 63A and the second arm 63B, along the longitudinal axis direction of the sheath 20. The casing 71 houses the first locking portion 72, the second locking portion 73, and a main body portion 74a of the lock switch 74. The sheath 20 is disposed in the casing 71 between the housing portion for the first locking portion 72 and the housing portion for the second locking portion 73.

[0065] The first locking portion 72 has a first pin 72a and a first spring member 72b. The first pin 72a is held in the casing 71 so as to be slidable in the longitudinal direction, and abuts against the protrusion 63A1 of the first arm 63A from its base end. The first spring member 72b is an example of an elastic member and is a compression coil spring that is disposed on the base end side of the first pin 72a and biases the first pin 72a toward its tip end. The base end of the first spring member 72b is supported by a main body 74a of the lock switch 74.

[0066] The second locking portion 73 is disposed at a position overlapping the first locking portion 72 and the sheath 20 in a plan view, and is disposed across the sheath 20 from the first locking portion 72. The second locking portion 73 has a second pin 73a and a second spring member 73b. The second pin 73a is held in the casing 71 so as to be slidable in the longitudinal direction, and abuts against the protrusion 63B1 of the second arm 63B from its proximal end. The second spring member 73b is an example of an elastic member and is a compression coil spring disposed on the proximal end side of the second pin 73a and biases the second pin 73a toward its distal end. The proximal end of the second spring member 73b is supported by the main body 74a of the lock switch 74.

[0067] The lock switch 74 has a main body 74a and a slider 74b. The main body 74a of the lock switch 74 is slidably supported in the longitudinal direction within the casing 71 and receives the reaction forces of the first spring member 72b and the second spring member 73b. The slider 74b is formed integrally with the main body 74a and is exposed to the outside of the operation unit main body 51 to receive operation by the operator. As shown in FIGS. 1(b) and 1(c), the position of the main body 74a of the lock switch 74 can be moved in the longitudinal direction by sliding the slider 74b of the lock switch 74 in the operation unit 50. When the slider 74b rides on the latch 60 on the operation unit main body 51, the slider 74b engages with the latch 60. This fixes the position of the main body 74a, which is formed integrally with the slider 74b.

[0068] In a first state in which the lock switch 74 is located on the base end side, the main body 74a that receives the first spring member 72b and the second spring member 73b is located on the base end side, and the first spring member 72b and the second spring member 73b are supported in an uncompressed state by the lock switch 74. Figures 10(a) and (b) schematically show the first lock portion 72 in the first state.

[0069] In the first state of the first locking portion 72, when the first arm 63A, which supports the second pulley 62A, moves toward the base end, the first pin 72a of the first locking portion 72 is pressed toward the base end by the first arm 63A, and the first spring member 72b is compressed (FIG. 10(b)). At this time, the first arm 63A is biased toward the tip end by the repulsive force of the first spring member 72b via the first pin 72a. In the first state, the compression of the first spring member 72b allows the first arm 63A to move toward the base end. When the first arm 63A moves, the second pulley 62A also moves along the trajectory of the first cam groove 57A.

[0070] The position of the second pulley 62A of the adjustment unit 54A in the first state is determined by the balance between the load on the first arm 63A and the repulsive force of the first spring member 72b. For example, when the tension of one operating line 30 increases, a load is applied in a direction narrowing the gap between the second pulley 62A of the adjustment unit 54A and the first pulley 61A, causing the first arm 63A to move toward the base end, and the second pulley 62A of the adjustment unit 54A also to move toward the base end. In contrast, when the tension of one operating line 30 decreases, the repulsive force of the first spring member 72b pushes the first arm 63A back toward the tip end, causing the second pulley 62A of the adjustment unit 54A to move toward the tip end (FIG. 10(a)). This widens the gap between the second pulley 62A of the adjustment unit 54A and the first pulley 61A.

[0071] By performing the above operation, an appropriate tension is applied to the operating wire 30 within a range that will not cause it to break, eliminating slack in the operating wire 30. This makes it possible to prevent the operating wire 30 from derailing from the first pulley 61A or the second pulley 62A within the operating unit 50, and to prevent the operating wires 30 from breaking due to tangling with each other.

[0072] Similarly, in the first state of the second locking unit 73, when the second arm 63B, which supports the second pulley 62B, moves toward the base end, the second pin 73a of the second locking unit 73 is pressed toward the base end by the second arm 63B, compressing the second spring member 73b. At this time, the second arm 63B is biased toward the tip end by the repulsive force of the second spring member 73b via the second pin 73a. Therefore, in the first state, the compression of the second spring member 73b allows the second arm 63B to move toward the base end independently of the first arm 63A. When the second arm 63B moves, the second pulley 62B also moves along the trajectory of the second cam groove 57B. The position of the second pulley 62B of the adjustment unit 54B in the first state is also determined by the balance between the load on the second arm 63B and the repulsive force of the second spring member 73b. The description regarding the operation of the adjustment unit 54B is the same as that of the adjustment unit 54A and the first arm 63A described above, and therefore a duplicated description will be omitted.

[0073] When the locking mechanism 55 is in the first state, the adjustment units 54A and 54B can change the distance between the second pulleys 62A and 62B and the first pulleys 61A and 61B, respectively. For example, when the catheter 10 is in a high-temperature environment due to heating during sterilization or transportation in summer, the sheath 20 expands more than the operating wire 30. In such an environment, when the locking mechanism 55 is in the first state and the sheath 20 expands, the adjustment units 54A and 54B shorten the distance between the pulleys compared to before expansion. This ensures that the adjustment units 54A and 54B ensure a flexure allowance for the operating wire 30 corresponding to the expansion of the sheath 20, thereby preventing breakage of the operating wire 30 due to the expansion of the sheath 20. Note that the operation when swelling deformation occurs in the sheath 20 when the locking mechanism 55 is in the first state is similar to that described above.

[0074] On the other hand, in a second state in which the lock switch 74 is positioned further distal than in the first state, the main body 74a that receives the first spring member 72b and the second spring member 73b is positioned further distal than in the first state. That is, in the second state, the first spring member 72b and the second spring member 73b are supported by the lock switch 74 in a more compressed state than in the first state. Note that Figure 10(c) schematically shows the first lock portion 72 in the second state.

[0075] In the second state of the first locking part 72, the first spring member 72b is compressed, and therefore the first arm 63A that abuts against the first pin 72a is pressed toward the distal end along the first cam groove 57A. The proximal end of the first pin 72a abuts against the main body part 74a, preventing it from moving toward the proximal end and positioning it (FIG. 10(c)). As a result, in the second state, the movement of the first arm 63A that abuts against the first pin 72a toward the proximal end is restricted, and the distance between the second pulley 62A and the first pulley 61A of the adjustment part 54A is maintained constant.

[0076] Similarly, in the second state of the second locking portion 73, the second spring member 73b is compressed, so that the second arm 63B, which abuts against the second pin 73a, is pressed toward the distal end along the second cam groove 57B. The proximal end of the second pin 73a abuts against the main body portion 74a, preventing it from moving toward the proximal end and positioning it in place. As a result, in the second state, the proximal movement of the second arm 63B, which abuts against the second pin 73a, is restricted, and the distance between the second pulley 62B and the first pulley 61B of the adjustment portion 54B is maintained constant.

[0077] When locking mechanism 55 is in the second state, adjustment units 54A and 54B fix the distance between second pulleys 62A and 62B and first pulleys 61A and 61B. In the second state, adjustment units 54A and 54B do not change the pulley distance, so when dial 53 is turned, the tension of operating wire 30 is transmitted directly to sheath 20. Therefore, during a procedure, locking mechanism 55 is set to the second state, and the operator can bend the distal portion of sheath 20 by rotating dial 53.

[0078] As described above, the locking mechanism 55 can simultaneously switch the adjustment portions 54A, 54B between the first state and the second state in response to the operation of the slider portion 74b.

[0079] In the locking mechanism 55, the spring constant of the first spring member 72b that urges the second pulley 62A of the adjustment unit 54A toward the tip end and the spring constant of the second spring member 73b that urges the second pulley 62B of the adjustment unit 54B toward the tip end are defined, for example, as follows: In the following explanation, the calculation of the spring constant of the first spring member 72b corresponding to the adjustment unit 54A will be described, and a duplicate explanation of the calculation of the spring constant of the second spring member 73b corresponding to the adjustment unit 54B will be omitted.

[0080] FIG. 11 is a diagram showing a schematic configuration of the adjustment unit 54A. The adjustment unit 54A has N (where N is an integer equal to or greater than 1) first pulleys 61A that are fixed pulleys and N-1 second pulleys 62A that are movable pulleys. FIG. 11 shows an example where N=3 (three first pulleys 61A and two second pulleys 62A). One operating wire 30 is alternately hung between the first pulleys 61A and the second pulleys 62A from the catheter 10 side (left side in FIG. 11) to the dial 53 side (right side in FIG. 11). In addition, a spring force is applied to the N-1 second pulleys 62A by first spring members 72b in a direction away from the first pulleys 61A (downward in FIG. 11).

[0081] 11, the catheter 10 side of one operating wire 30 is considered to be the fixed end, and the spring constant of the first spring member 72b is defined as k, the amount of displacement of the second pulley 62A relative to the first pulley 61A as x, and the breaking strength of one operating wire 30 as S. In the above case, the load applied from the first spring member 72b to the entire second pulley 62 is indicated by kx, and the load on the dial 53 side of one operating wire 30 is indicated by kx / 2(N-1). From the perspective of preventing breakage of one operating wire 30 in the adjustment unit 54A, the spring constant k of the first spring member 72b may be set so as to satisfy the following formula (1). kx<2S(N-1) ……Formula (1)

[0082] When the spring constant k of the first spring member 72b satisfies the relationship of formula (1), it is possible to prevent the first spring member 72b from excessively biasing the second pulley 62A and causing one of the operating wires 30 to break in the adjustment section 54A.

[0083] When setting the spring constant k of the first spring member 72b based on the above formula (1), the safety factor n of the operating wire 30 may be taken into consideration. Here, the safety factor n is not particularly limited, but, for example, it is preferable to set the lower limit to a value that is effective for preventing the operating wire 30 from breaking. On the other hand, when setting the upper limit of the safety factor n, it is preferable to set it taking into consideration, for example, the shapes and dimensions of the sheath 20, operating wire 30, and operating unit 50, the structure and quality of the materials used, the range of loads that can be applied to the operating wire 30, etc.

[0084] The effects of the catheter 10 of this embodiment will be described below. The catheter 10 of this embodiment includes a sheath 20 (tubular body) to be inserted into a biological lumen, a plurality of operating wires 30 that are inserted through the sheath 20 and have their tips connected to a distal portion of the sheath 20, an operating unit main body 51 provided in the proximal portion of the sheath 20, a dial 53 (operating member) to which the base ends of the operating wires 30 are fixed and which is rotatably attached to the operating unit main body 51 and which, when rotated, applies a traction force to the operating wires 30 to bend the distal portion of the sheath 20, and a plurality of adjustment units 54A, 54B provided in the operating unit main body 51 corresponding to each operating wire 30 and which form a flexure allowance for the operating wire 30 in response to expansion of the sheath 20. Each adjustment unit 54A, 54B has a plurality of pulleys (61A, 62A and 61B, 62B) whose distance from each other can be changed, and the length of the operating wire 30 suspended between the pulleys can be freely adjusted. In this embodiment, the adjustment units 54A and 54B provided on the catheter 10 ensure a sufficient deflection allowance for each of the operating wires 30 and the other operating wire 30 when the sheath 20 is expanded. This makes it possible to prevent damage to the operating wires 30 or the sheath 20 caused by the expansion of the sheath 20 during sterilization of the sheath 20 or in a high-temperature environment. Furthermore, the adjustment units 54A and 54B use multiple pulleys whose distances can be changed to adjust the length of the operating wire 30 suspended between the pulleys. This makes it possible to ensure a flexure allowance for the operating wire 30 at a position offset from the longitudinal direction of the sheath 20, or to ensure a flexure allowance by folding the operating wire 30 multiple times between the pulleys. As a result, in this embodiment, the longitudinal stroke required for ensuring flexure of the operating wire 30 by the adjustment units 54A and 54B is shortened, thereby realizing a control unit main body 51 with a shortened longitudinal length. For example, in the catheter 10 of this embodiment, because the longitudinal length of the control unit main body 51 is short, when a small-diameter catheter is inserted into the catheter 10 in a nested manner, the catheter on the inner diameter side can be easily passed through. Furthermore, because the longitudinal length of the control unit main body 51 of the catheter 10 of this embodiment is short, it can be combined with even a catheter with a relatively short inner diameter side, thereby broadening the range of combinations with inner diameter catheters.

[0085] Each of adjustment units 54A, 54B has a plurality of pulleys, namely, first pulleys 61A, 61B and second pulleys 62A, 62B that are movable relative to the first pulleys, and is capable of changing the perpendicular distance between the axis of first pulleys 61A, 61B and the axis of second pulleys 62A, 62B. By configuring second pulleys 62A, 62B to move relative to first pulleys 61A, 61B, the structure of adjustment units 54A, 54B is simplified, making it easier to reduce the size of operation unit main body 51 and the length in the longitudinal direction.

[0086] Furthermore, each of the adjustment units 54A, 54B further includes a first spring member 72b and a second spring member 73b (elastic member) that bias the second pulleys 62A, 62B in a direction that separates them from the first pulleys 61A, 61B. As a result, when the sheath 20 returns to its original length from the expanded state, the adjustment units 54A, 54B adjust the distance between the first pulleys 61A, 61B and the second pulleys 62A, 62B, and loosening of the operating wire 30 can be eliminated.

[0087] Furthermore, in each of the adjustment units 54A, 54B, the operating wire 30 is stretched so as to make multiple turns around the first pulleys 61A, 61B and the second pulleys 62A, 62B. By arranging the operating wire 30 so as to make multiple turns around the first pulleys 61A, 61B and the second pulleys 62A, 62B, a large flex allowance for the operating wire 30 can be ensured even if the movement distance of the first pulleys 61A, 61B and the second pulleys 62A, 62B is shortened. Therefore, with the configuration of the adjustment units 54A, 54B described above, it becomes easier to reduce the size of the operation unit main body 51 and the length in the longitudinal direction. In addition, in the configuration of the adjustment units 54A, 54B described above, the force of the spring member that separates the first pulleys 61A, 61B and the second pulleys 62A, 62B is received by the operating wire 30 that is wound around it in a distributed manner at multiple points, making it less likely that the operating wire 30 will break at the adjustment units 54A, 54B.

[0088] Furthermore, in each of adjustment units 54A, 54B, the movement direction of the second pulley relative to the first pulley is a direction intersecting the longitudinal axis direction of sheath 20. This allows the longitudinal lengths of adjustment units 54A, 54B and operation unit main body 51 to be further shortened compared to when the second pulley is moved along the longitudinal axis direction.

[0089] Furthermore, in each of the adjustment units 54A, 54B, the diameter D of the first pulley and the second pulley is a value that satisfies D / d>40, where d is the diameter of the operating wire. This makes it difficult for excessive stress to be applied to the operating wire 30 that comes into contact with the first pulley or the second pulley, and prevents the operating wire 30 from breaking at the adjustment units 54A, 54B.

[0090] Each of the adjustment units 54A, 54B further includes a locking mechanism 55 that switches between a first state in which the multiple pulleys are relatively movable in a direction perpendicular to the axis and a second state in which the relative movement of the multiple pulleys is restricted. This allows the locking mechanism 55 to be set to the first state during sterilization processing when not in use or in a high-temperature environment, thereby preventing breakage of the operating wire 30. Furthermore, by setting the locking mechanism 55 to the second state during a procedure, tension when the operating wire 30 is pulled can be reliably transmitted to the distal portion of the sheath 20.

[0091] Furthermore, the dial 53 of this embodiment is disposed with its rotation axis tilted relative to the radial direction perpendicular to the long axis direction of the sheath 20. If the rotation axis of the dial 53 were disposed so that it coincided with the radial direction, a space equivalent to the diameter of the dial 53 would be required in the long axis direction of the operation unit main body 51. In contrast, if the rotation axis of the dial 53 is tilted relative to the radial direction as described above, the space occupied by the dial 53 in the long axis direction of the operation unit main body 51 is reduced, and the long axis length of the operation unit main body 51 can be shortened. In particular, the rotation axis of the dial 53 in this embodiment is parallel to the long axis direction of the sheath 20. This allows the space occupied by the dial 53 in the long axis direction of the operation unit main body 51 to be reduced to the thickness of the dial 53, thereby further shortening the long axis length of the operation unit main body 51.

[0092] The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

[0093] In the above embodiment, a configuration example was described in which the second pulleys move obliquely in the adjustment units 54A and 54B so that the distance between them increases from the distal end to the proximal end, but the movement direction of the second pulleys is not limited to the above. For example, the movement direction of the second pulleys in the adjustment units 54A and 54B may be a radial direction perpendicular to the longitudinal axis direction, or the second pulleys in the adjustment units 54A and 54B may move obliquely so that the distance between them increases from the proximal end to the distal end. Furthermore, the first pulley may be moved instead of the second pulley.

[0094] In the above embodiment, an example was described in which a compression coil spring was used as the elastic member that separates the first and second pulleys of the adjustment unit, but the elastic member is not limited to this. For example, the elastic member that separates the first and second pulleys of the adjustment unit may be a leaf spring, a non-metallic spring using rubber, sponge, plastic spring, or the like, or a fluid spring such as an air spring or liquid spring.

[0095] In the above embodiment, an example has been described in which the dial 53 of the operation unit 50 is disposed so that its rotation axis is parallel to the long axis direction of the sheath 20. However, the arrangement of the dial 53 of the operation unit 50 is not limited to the above, and for example, the dial 53 may be disposed so that the rotation axis of the dial 53 is inclined both in the long axis direction and the radial direction of the sheath 20.

[0096] Furthermore, the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0097] The disclosure of the above embodiment encompasses the following technical ideas. (1) A catheter comprising: a tubular body to be inserted into a biological lumen; a plurality of operating wires inserted into the tubular body, each having a tip connected to a distal portion of the tubular body; an operating unit body provided in the proximal portion of the tubular body; an operating member to which the base ends of the operating wires are fixed and which is rotatably attached to the operating unit body, and which, when rotated, applies traction to the operating wires to bend the distal portion of the tubular body; and a plurality of adjustment units provided in the operating unit body corresponding to each of the operating wires, which form a flexure allowance for the operating wires in response to expansion of the tubular body, wherein each of the adjustment units has a plurality of pulleys whose distance from each other can be changed, and the length of the operating wire suspended between the pulleys can be freely adjusted. (2) A catheter as described in (1) above, wherein each of the adjustment units has a first pulley and a second pulley that is movable relative to the first pulley as the plurality of pulleys, and the perpendicular distance between the axis of the first pulley and the axis of the second pulley can be changed. (3) The catheter according to (2) above, wherein each of the adjustment sections further includes an elastic member that biases the second pulley in a direction that moves the second pulley away from the first pulley. (4) A catheter described in (3) above, in which the operating line is alternately passed over the first pulley and the second pulley, and the number of times the operating line is passed over the first pulley is greater than the number of times the operating line is passed over the second pulley. (5) The catheter according to (4) above, wherein the spring constant k of the elastic member satisfies the relationship of the following formula (1) with respect to the displacement x of the second pulley relative to the first pulley, the breaking strength S of the operating wire, and the number N of the first pulleys (where N is an integer of 2 or more): kx<2S(N-1) ……Formula (1) (6) A catheter according to any one of (2) to (5) above, wherein the operating wire is hung over the first pulley and the second pulley so as to make multiple turns around them. (7) A catheter according to any one of (2) to (6) above, wherein the direction of movement of the second pulley relative to the first pulley is a direction intersecting the longitudinal axis direction of the tubular body. (8) A catheter described in any one of (2) to (7) above, wherein the diameter D of the first pulley and the second pulley is a value that satisfies D / d>40 when the diameter of the operating wire is d. (9) A catheter described in any of (1) to (8) above, wherein each of the adjustment units further has a locking mechanism that switches between a first state in which the multiple pulleys can move relatively in a direction perpendicular to the axis, and a second state in which the relative movement of the multiple pulleys is restricted. (10) A catheter according to any one of (1) to (9) above, wherein the operating member is arranged with its rotation axis tilted relative to a direction perpendicular to the longitudinal axis direction of the tubular body. (11) The catheter according to (10) above, wherein the rotation axis of the operating member is parallel to the longitudinal axis direction of the tubular body. (12) The catheter according to any one of (1) to (11), wherein the linear expansion coefficient of the tubular body is greater than the linear expansion coefficient of the operating line. (13) A catheter according to any one of (1) to (12) above, wherein the swelling coefficient of the tubular body is greater than the swelling coefficient of the operating wire. [Explanation of symbols]

[0098] 10...catheter, 20...sheath (tubular body), 21...inner layer, 21a...main lumen, 22...first reinforcing layer, 23...outer layer, 24...hydrophilic coating, 25...hollow tube, 25a...sub-lumen, 29...second reinforcing layer, 29a...reinforcing wire, 30...operating wire, 40...marker, 50...operating section, 51...operating section main body, 52...hub connector, 53...dial (operating member), 54A, 54B...adjusting section, 55...locking mechanism, 56...protector, 57A...first cam groove , 57B...second cam groove, 58...wire guide, 59...shaft, 60...latch portion, 61A, 61B...first pulley, 62A, 62B...second pulley, 63A...first arm, 63B...second arm, 63A1, 63B1...projection portion, 71...casing, 72...first lock portion, 72a...first pin, 72b...first spring member, 73...second lock portion, 73a...second pin, 73b...second spring member, 74...lock switch, 74a...main body portion, 74b...slider portion

Claims

1. a tubular body to be inserted into a biological lumen; a plurality of operating wires inserted through the tubular body and each having a tip connected to a distal portion of the tubular body; an operation portion main body provided at a proximal portion of the tubular main body; an operating member to which a proximal end of the operating wire is fixed and which is rotatably attached to the operating portion main body, and which applies a traction force to the operating wire by a rotational operation to bend the distal portion of the tubular main body; a plurality of adjustment sections provided in the operation section main body corresponding to each of the operation wires, the adjustment sections forming a deflection allowance of the operation wire in response to expansion of the tubular main body; Each of the adjustment units has a plurality of pulleys whose distance from each other can be changed, and the length of the operating line suspended between the pulleys is freely adjustable. catheter.

2. Each of the adjustment units has, as the plurality of pulleys, a first pulley and a second pulley that is movable relative to the first pulley, and is capable of changing the distance between the axis of the first pulley and the axis of the second pulley in the perpendicular direction. The catheter of claim 1 .

3. Each of the adjustment units further includes an elastic member that biases the second pulley in a direction that moves the second pulley away from the first pulley. The catheter of claim 2.

4. The operating line is alternately wound around the first pulley and the second pulley, and the number of times the operating line is wound around the first pulley is greater than the number of times the operating line is wound around the second pulley. The catheter of claim 3.

5. The spring constant k of the elastic member satisfies the relationship of the following formula (1) with respect to the displacement x of the second pulley relative to the first pulley, the breaking strength S of the operating wire, and the number N of the first pulleys (where N is an integer of 2 or more): The catheter according to claim 4 kx<2S(N-1)...Formula (1)

6. The operating line is stretched over the first pulley and the second pulley so as to make a plurality of turns therearound. The catheter of claim 2.

7. The second pulley moves relative to the first pulley in a direction intersecting the longitudinal axis of the tubular body. The catheter of claim 2.

8. The diameter D of the first pulley and the second pulley is a value that satisfies D / d>40 when the diameter of the operating wire is d. The catheter of claim 2.

9. Each of the adjustment units further includes a locking mechanism that switches between a first state in which the plurality of pulleys are relatively movable in a direction perpendicular to the axis and a second state in which the relative movement of the plurality of pulleys is restricted. The catheter of claim 1 .

10. The operating member is disposed with its rotation axis tilted relative to a direction perpendicular to the longitudinal axis of the tubular body. The catheter according to any one of claims 1 to 9.

11. The rotation axis of the operating member is parallel to the longitudinal axis of the tubular body. The catheter of claim 10.

12. The linear expansion coefficient of the tubular body is greater than the linear expansion coefficient of the operating line. The catheter according to any one of claims 1 to 9.

13. The swelling coefficient of the tubular body is greater than the swelling coefficient of the operating wire. The catheter according to any one of claims 1 to 9.

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