Catheter shaft and catheter

Abstract

A catheter shaft 20 includes: a main lumen tube 41 forming a main lumen 40; and a first sub-lumen tube 43 forming a first sub-lumen 42. The first sub-lumen tube 43 is provided with a facing surface 43a formed in a planar shape. The main lumen tube 41 is provided with a facing surface 41a formed in a planar shape. The first sub-lumen tube 43 is disposed so that the facing surface 43a is in contact with the facing surface 41a of the main lumen tube 41.

Description

Catheter shaft and catheter

[0001] The present invention relates to a catheter with a deflectable tip.

[0002] In catheters such as electrode catheters that are inserted into the heart through blood vessels, the distal end (tip) of the catheter shaft inserted into the body is deflected by pulling a control wire (pull wire) inserted into the catheter shaft with a control unit attached to the proximal end of the catheter shaft located outside the body. Among the performance requirements for such catheters is a parameter called planarity, which indicates the inclination of the distal end when it bends left and right.

[0003] JP 2017-113329 A

[0004] In the catheter disclosed in Patent Document 1, a main lumen with a circular cross section is disposed at the center of the catheter shaft, and two sub-tubes through which operating wires are inserted are disposed 180 degrees opposite each other across the center of the catheter shaft, and a retaining wire is provided so as to be wound together with the two sub-tubes and the inner layer forming the main lumen.

[0005] In a catheter with this configuration, good planarity is achieved when the two sub-tubes are arranged 180 degrees apart. However, when the retaining wire is wound around the two sub-tubes during the manufacturing process of the catheter shaft, there is a possibility that the two sub-tubes may shift from the 180-degree opposing position. This positional shift of the sub-tubes may degrade the planarity.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a catheter shaft with improved planarity.

[0007] In order to solve the above problems, a catheter shaft according to one aspect of the present invention includes a main lumen tube that forms a main lumen and a sub-lumen tube that forms a sub-lumen. The sub-lumen tube has a first flat surface on at least a portion thereof and a second flat surface provided radially outward from the main lumen. The sub-lumen tube is arranged so that the first flat surface is in contact with the second flat surface.

[0008] The second flat surface may be provided on a portion of the main lumen tube.

[0009] The catheter shaft may further include an intermediate layer provided to cover the main lumen tube, and the second plane may be provided on a portion of the intermediate layer.

[0010] Another aspect of the present invention is a catheter, which includes the catheter shaft described above, a control wire inserted through the sub-lumen, and a control section provided at the proximal end of the catheter shaft for pulling the control wire.

[0011] According to the present invention, a catheter shaft with improved planarity can be provided.

[0012] FIG. 7( a) is a schematic plan view of a catheter according to an embodiment. FIG. 7( b) is a schematic cross-sectional view taken along line AA of the catheter shown in FIG. 1. FIG. 7( c) is an enlarged view of the periphery of a sub-lumen tube. FIG. 7( a) is a view for explaining the width of a sub-lumen. FIG. 7( c) is a view for explaining the height of a sub-lumen. FIG. 7( e) is a view for explaining the opposing surface of a main lumen tube. FIG. 7( a) to FIG. 7( e) are diagrams showing a method for manufacturing a catheter shaft. FIG. 7( a) is a schematic cross-sectional view of a catheter shaft according to another embodiment. FIG. 7( b) is an enlarged view of the periphery of a sub-lumen tube. FIG. 7( c) is a schematic cross-sectional view of a catheter shaft according to a modified example.

[0013] Hereinafter, embodiments for carrying out the present invention will be described. The same or equivalent components will be given the same reference numerals, and redundant explanations will be omitted. In each drawing, for the sake of convenience, components will be omitted, enlarged, or reduced as appropriate. The drawings should be viewed in accordance with the orientation of the reference numerals.

[0014] Fig. 1 is a schematic plan view of a catheter 10 according to an embodiment. The catheter 10 according to the embodiment is a catheter sheath used as an auxiliary tool when placing the distal end of a catheter tube inserted into a blood vessel at a desired placement site. The catheter 10 is a bidirectional type whose tip portion can be deflected in both directions. As shown in Fig. 1, the catheter 10 includes a catheter shaft 20 and an operating section 30.

[0015] The catheter shaft 20 is flexible and can be bent. The control section 30 is attached to the proximal end of the catheter shaft 20 and includes a handle 31 and a rotating plate 32.

[0016] The handle 31 is the part that the operator grasps when using the catheter 10. Various thin wires (conductors and operating wires) are drawn out from the inside of the catheter shaft 20 into the handle 31.

[0017] The rotating plate 32 is a member used to deflect (bend) the distal end of the catheter shaft 20. The rotating plate 32 has a protrusion 32a, and as shown in Figure 1, by pressing the protrusion 32a, the rotating plate 32 can be rotated in the direction of the arrow.

[0018] 2 is a schematic AA cross-sectional view of the catheter 10 shown in Fig. 1, showing a cross section perpendicular to the extension direction (axial direction) of the catheter shaft 20. Hereinafter, when describing the positional relationship and shape of each component of the catheter shaft 20, unless otherwise specified, the positional relationship and shape will be described in the cross section perpendicular to the axial direction of the catheter shaft 20.

[0019] The catheter shaft 20 includes a main lumen tube 41 that defines a main lumen 40 , a first sub-lumen tube 43 that defines a first sub-lumen 42 , and a second sub-lumen tube 45 that defines a second sub-lumen 44 .

[0020] The catheter shaft 20 has a substantially circular outer shape. The main lumen 40 also has a substantially circular shape. The main lumen tube 41 is arranged so that the main lumen 40 is coaxial with the center C of the catheter shaft 20. An electrode catheter, for example, can be inserted through the main lumen 40.

[0021] The first sub-lumen tube 43 and the second sub-lumen tube 45 are disposed outside the main lumen tube 41. That is, in the catheter shaft 20, the first sub-lumen 42 and the second sub-lumen 44 are formed outside the main lumen 40. The first sub-lumen tube 43 and the second sub-lumen tube 45 are disposed opposite the main lumen tube 41. The first sub-lumen 42 and the second sub-lumen 44 are disposed so as to be 180 degrees opposed to each other with the center C of the catheter shaft 20 as the center.

[0022] The main lumen tube 41, the first sub-lumen tube 43, and the second sub-lumen tube 45 may be made of a fluorine-based resin such as polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane (PFA), etc. The thickness of the main lumen tube 41, the first sub-lumen tube 43, and the second sub-lumen tube 45 may be approximately 10 μm to 200 μm (e.g., 30 μm).

[0023] The catheter shaft 20 further includes a reinforcing wire 48 that bundles the main lumen tube 41 and the first and second sub-lumen tubes 43 and 45. The reinforcing wire 48 may be formed of a braided wire in which multiple wires (not shown) are woven into a cylindrical shape. Alternatively, the reinforcing wire 48 may be formed of a coil made of one or multiple wires. The reinforcing wire 48 serves to enhance the torque transmission and kink resistance of the catheter shaft 20. Torque transmission here refers to the ability to transmit torque applied to the control section 30 to the distal end 28 of the catheter shaft 20. The wires that make up the reinforcing wire 48 may be made of metals such as stainless steel and Ni-Ti alloys, as well as resins.

[0024] The catheter shaft 20 further includes an outer layer 49 disposed on the outside of the main lumen tube 41. The outer layer 49 is disposed so as to cover the main lumen tube 41, the first sub-lumen tube 43, the second sub-lumen tube 45, and the reinforcing wire 48. The first sub-lumen tube 43 and the second sub-lumen tube 45 are contained within the outer layer 49. The outer layer 49 may be made of a synthetic resin such as PA, a PA-based elastomer, or TPU. As shown in FIG. 2 , the outer layer 49 is also disposed between the main lumen tube 41 and the reinforcing wire 48, and this outer layer 49 fixes the positional relationship between the main lumen tube 41 and the first and second sub-lumen tubes 43 and 45.

[0025] A first manipulation wire 46 is inserted through the first sublumen 42. A second manipulation wire 47 is inserted through the second sublumen 44. The manipulation wires are also called pull wires. The first manipulation wire 46 and the second manipulation wire 47 are wires used to manipulate the direction of the distal end 28 (see FIG. 1 ) of the catheter shaft 20, and may be made of SUS wire, tungsten, a Ni-Ti based superelastic alloy, or the like.

[0026] The distal ends (tips) of the first manipulation wire 46 and the second manipulation wire 47 are fixed to the distal portion of the catheter shaft 20 by anchors, solder, or the like, and the proximal ends (base ends) are attached to the rotating plate 32 of the manipulation unit 30. As a result, the tension of the first manipulation wire 46 and the second manipulation wire 47 changes in response to the rotation of the rotating plate 32 (operation of the rotating plate 32), allowing the first manipulation wire 46 and the second manipulation wire 47 to be pulled along the central axis inside the catheter shaft 20. For example, when the first manipulation wire 46 is pulled by operating the rotating plate 32, the distal end 28 of the catheter shaft 20 is deflected in direction A (see FIG. 1) shown in FIG. 1. When the second manipulation wire 47 is pulled by operating the rotating plate 32, the distal end 28 of the catheter shaft 20 is deflected in direction B (see FIG. 1), which is opposite to direction A.

[0027] Figure 3 is an enlarged view of the area around the sub-lumen tube. The catheter shaft 20 according to this embodiment is characterized by the shape of the sub-lumen tube and the shape of the main lumen tube 41 facing the sub-lumen tube. Here, the first sub-lumen tube 43 will be described as an example, but the same applies to the second sub-lumen tube 45. For ease of explanation, the first operating wire 46 is not shown in Figure 3.

[0028] 3, the main lumen tube 41 and the first sub-lumen tube 43 are disposed to face each other. The main lumen tube 41 has an opposing surface 41a facing the first sub-lumen tube 43. The first sub-lumen tube 43 has an opposing surface 43a facing the main lumen tube 41.

[0029] In this embodiment, the opposing surface 43a of the first sub-lumen tube 43 corresponds to the "first plane," and the opposing surface 41a of the main lumen tube 41 corresponds to the "second plane." The opposing surface 43a is provided on a portion of the first sub-lumen tube 43, and the opposing surface 41a is provided on a portion of the main lumen tube 41. In this embodiment, the opposing surface 41a is provided radially outward from the main lumen 40.

[0030] In this embodiment, the opposing surface 41a of the main lumen tube 41 is formed to be flat. The opposing surface 43a of the first sub-lumen tube 43 is also formed to be flat. The opposing surface 41a of the main lumen tube 41 and the opposing surface 43a of the first sub-lumen tube 43 are in contact with each other.

[0031] The main lumen tube 41 and the first sub-lumen tube 43 are bundled together by a reinforcing wire 48. If the main lumen tube 41 and the first sub-lumen tube 43 were both circular, the first sub-lumen tube 43 would move on the surface of the main lumen tube 41 when they were bundled together by the reinforcing wire 48, and the position of the first sub-lumen tube 43 might shift from its designed position (i.e., the position where the first sub-lumen 42 and the second sub-lumen 44 are 180 degrees opposed to each other across the center C). By making the opposing surfaces 41a of the main lumen tube 41 and 43a of the first sub-lumen tube 43 flat as in this embodiment, the first sub-lumen tube 43 is stabilized on the surface of the main lumen tube 41, making it less likely that the first sub-lumen tube 43 will shift from its designed position when they are bundled together by the reinforcing wire 48. The same is true for the second sub-lumen 44. Therefore, according to the catheter shaft 20 of this embodiment, the first sub-lumen 42 and the second sub-lumen 44 can be arranged at the designed positions, thereby improving planarity.

[0032] At least a portion of the opposing surface 41a of the main lumen tube 41 may be flat, but it is preferable that the entire opposing surface 41a be flat, as shown in Fig. 3. Furthermore, at least a portion of the opposing surface 43a of the first sub-lumen tube 43 may be flat, but it is preferable that the entire opposing surface 43a be flat, as shown in Fig. 3.

[0033] Although the main lumen 40 has been described above as having a substantially circular shape, strictly speaking, it is not a perfect circle. As shown in FIG. 2 , the upper and lower ends of the circle are cut off. However, excluding these upper and lower ends, the main lumen 40 is circular. Furthermore, the first sublumen 42 and the second sublumen 44 have an oval shape. As shown in FIG. 2 , the first operating wire 46 and the second operating wire 47 inserted into the first sublumen 42 and the second sublumen 44 have rectangular cross sections corresponding to the oval shapes of the sublumens. However, if the widths of the first sublumen 42 and the second sublumen 44 are narrowed to form shapes closer to square, operating wires with circular cross sections can be used. The width of the operating wire is preferably 50% or more of the width of the sublumen. This reduces misalignment of the operating wire in the width direction, improving flatness, and prevents the operating wire from being twisted within the sublumen during assembly, preventing a decrease in slidability during operation.

[0034] The height Hs of the first sublumen 42 and the second sublumen 44 may be approximately uniform from one end to the other. Here, "approximately uniform height Hs" means that the maximum and minimum values ​​of height Hs are within ±15%, more preferably within ±10%, of the average value of height Hs. The average value of height Hs may be determined, for example, by dividing the sublumen into three equal parts in the width direction and averaging the heights Hs of each part. Height Hs may be measured, for example, with a digital microscope.

[0035] 4 is a diagram illustrating the width of the sub-lumens. The width Ws of the first sub-lumen 42 and the second sub-lumen 44 may be within 30% to 90% of the width Wm of the opposing surface 41a of the main lumen tube 41, preferably within 50% to 90%, and more preferably within 70% to 90%.

[0036] 5 is a diagram illustrating the height of the sub-lumens. The height Hs of the first sub-lumen 42 and the second sub-lumen 44 may be within 30% of the thickness T of the outer layer 49. The thickness T of the outer layer 49 is the thickness of the outer layer 49 at the portion where the sub-lumen tube is provided, and more specifically, is the distance from the opposing surface 41 a of the main lumen tube 41 to the outer surface of the outer layer 49.

[0037] 6 is a diagram illustrating the opposing surface 41 a of the main lumen tube 41. The distance D from the center C of the main lumen 40 to the opposing surface 41 a of the main lumen tube 41 may be 80% or more of the radius R of the main lumen 40, and preferably 90% or more of the radius R of the main lumen 40.

[0038] In the catheter shaft 20 according to this embodiment, the first sub-lumen tube 43 and the second sub-lumen tube 45 are deformable radially outward of the catheter shaft 20. Therefore, the opposing surface (flat surface) of the main lumen tube 41 is not directly pressed by the reinforcing wire 48, and is therefore able to expand radially outward of the catheter shaft 20. This allows, for example, a catheter having a diameter approximately the same as the diameter of the main lumen 40 (radius R × 2) to be passed through the main lumen 40.

[0039] 7(a) to 7(e) show a method for manufacturing a catheter shaft.

[0040] 7(a), the main lumen tube 41 is formed by coating the surface of the main lumen core material 50 made of SUS or the like. The main lumen core material 50 has a flat surface formed thereon that corresponds to the flat surface of the main lumen tube 41. Similarly, the first sub-lumen tube 43 and the second sub-lumen tube 45 are formed by coating the surface of the sub-lumen core material. The sub-lumen core material 51 has a flat surface formed thereon that corresponds to the flat surfaces of the first sub-lumen tube 43 and the second sub-lumen tube 45.

[0041] Methods for covering a core material with a lumen tube include (1) a method in which only the lumen tube is extruded, (2) a method in which the lumen tube and shrink tube are placed over the core material and then heat-shrunk, and (3) a method in which the lumen tube is pulled while it is placed over the core material, reducing its diameter and making it adhere tightly.

[0042] 7(b), the first sub-lumen tube 43 and the second sub-lumen tube 45 are placed on the flat surface of the main lumen tube 41. The first sub-lumen tube 43 and the second sub-lumen tube 45 are placed at positions that are 180 degrees opposite each other.

[0043] Next, as shown in FIG. 7( c ), the main lumen tube 41 , the first sub-lumen tube 43 and the second sub-lumen tube 45 are bundled together with a reinforcing wire 48 .

[0044] Next, as shown in FIG. 7( d ), an outer layer 49 is provided so as to cover the main lumen tube 41 , the first sub-lumen tube 43 , the second sub-lumen tube 45 and the reinforcing wire 48 .

[0045] 7(e), the main lumen core material 50 and the sub-lumen core material 51 are pulled out to form the main lumen 40, the first sub-lumen 42, and the second sub-lumen 44. In this way, the catheter shaft 20 is obtained.

[0046] Figure 8 shows a cross section perpendicular to the extension direction (axial direction) of a catheter shaft 120 according to another embodiment. This catheter shaft 120 is also applicable to the catheter 10 shown in Figure 1. Hereinafter, when describing the positional relationship and shape of each component of the catheter shaft 120, unless otherwise specified, the positional relationship and shape will be described in a cross section perpendicular to the axial direction of the catheter shaft 120.

[0047] The catheter shaft 120 includes a main lumen tube 141 that defines a main lumen 140 , a first sub-lumen tube 143 that defines a first sub-lumen 142 , and a second sub-lumen tube 145 that defines a second sub-lumen 144 .

[0048] The catheter shaft 120 has a circular outer shape. The main lumen 140 also has a circular shape. The main lumen tube 141 is arranged so that the main lumen 140 is coaxial with the center C of the catheter shaft 120. An electrode catheter, for example, can be inserted through the main lumen 140.

[0049] The first sublumen tube 143 and the second sublumen tube 145 are disposed radially outward of the main lumen tube 141. That is, in the catheter shaft 120, the first sublumen 142 and the second sublumen 144 are formed radially outward of the main lumen 140. The first sublumen 142 and the second sublumen 144 are disposed to face each other 180 degrees with respect to the center C of the catheter shaft 120.

[0050] The main lumen tube 141, the first sub-lumen tube 143, and the second sub-lumen tube 145 may be made of a fluorine-based resin such as polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane (PFA), etc. The thickness of the main lumen tube 141, the first sub-lumen tube 143, and the second sub-lumen tube 145 may be approximately 10 μm to 200 μm (e.g., 30 μm).

[0051] The catheter shaft 120 according to this embodiment further includes an intermediate layer 160 provided to cover the main lumen tube 141. The intermediate layer 160 can be made of a synthetic resin such as PA, a PA-based elastomer, or TPU. In this embodiment, the intermediate layer 160 has a first recess 161 and a second recess 162 formed to face each other at 180 degrees relative to the center C of the catheter shaft 120. The first sub-lumen tube 143 is fitted into the first recess 161, and the second sub-lumen tube 145 is fitted into the second recess 162.

[0052] The catheter shaft 120 further includes a reinforcing wire 148 that bundles the intermediate layer 160 and the first and second sub-lumen tubes 143, 145. The reinforcing wire 148 may be formed of a braided wire in which multiple wires (not shown) are braided into a tubular shape. Alternatively, the reinforcing wire 148 may be formed of a coil made of one or multiple wires. The reinforcing wire 148 serves to improve the torque transmission and kink resistance of the catheter shaft 120. The wires that make up the reinforcing wire 148 may be made of metals such as stainless steel and Ni-Ti alloys, as well as resins.

[0053] The catheter shaft 120 further includes an outer layer 149 provided to cover the intermediate layer 160, the first sub-lumen tube 143, the second sub-lumen tube 145, and the reinforcing wire 148. The outer layer 149 can be made of a synthetic resin such as PA, a PA-based elastomer, or TPU. For convenience, in Figure 8, the outer layer 149 is depicted as being disposed on the outside of the reinforcing wire 148; however, it should be noted that in reality, the outer layer 149 is also present between the wires that make up the reinforcing wire 148, and is in contact with the intermediate layer 160, the first sub-lumen tube 143, and the second sub-lumen tube 145.

[0054] A first manipulation wire 146 is inserted through the first sub-lumen 142. A second manipulation wire 147 is inserted through the second sub-lumen 144. Manipulation wires are also called pull wires. The first manipulation wire 146 and the second manipulation wire 147 are wires used to manipulate the direction of the distal end of the catheter shaft 120, and may be made of SUS wire, tungsten, a Ni-Ti based superelastic alloy, or the like.

[0055] The distal ends (tips) of the first manipulation wire 146 and the second manipulation wire 147 are fixed to the distal portion of the catheter shaft 120 by anchors, solder, or the like, and the proximal ends (base ends) are attached to the rotating plate 32 of the manipulation unit 30. As a result, the tension of the first manipulation wire 146 and the second manipulation wire 147 changes in response to the rotation of the rotating plate 32 (operation of the rotating plate 32), allowing the first manipulation wire 146 and the second manipulation wire 147 to be pulled along the central axis inside the catheter shaft 120. For example, when the first manipulation wire 146 is pulled by operating the rotating plate 32, the distal end of the catheter shaft 120 is deflected in direction A (see FIG. 1) shown in FIG. 1. When the second manipulation wire 147 is pulled by operating the rotating plate 32, the distal end of the catheter shaft 120 is deflected in direction B (see FIG. 1), which is opposite to direction A. In another embodiment, a manipulation mechanism other than the rotating plate 32 may be used. For example, a circumferential rotation operation mechanism or a push-pull operation mechanism for the catheter shaft 20 may be used.

[0056] Figure 9 is an enlarged view of the area around the sub-lumen tube. The catheter shaft 120 according to this embodiment is characterized by the shape of the sub-lumen tube and the shape of the intermediate layer 160 with which the sub-lumen tube comes into contact. Here, the first sub-lumen tube 143 will be described as an example, but the same applies to the second sub-lumen tube 145. For the sake of explanation, the first operating wire 146 is not shown in Figure 9.

[0057] As described above, in the catheter shaft 120 according to this embodiment, a first recess 161 is provided in the intermediate layer 160, and the first sub-lumen tube 143 is fitted into this first recess 161. The first recess 161 has a bottom surface 161a and side surfaces 161b and 161c on either side of the bottom surface 161a. The side surfaces 161b and 161c are formed to be approximately perpendicular to the bottom surface 161a. Meanwhile, the first sub-lumen tube 143 has an opposing surface 143a that faces the bottom surface 161a of the first recess 161.

[0058] In this embodiment, the opposing surface 143a of the first sub-lumen tube 143 corresponds to the "first plane," and the bottom surface 161a of the first recess 161 formed in the intermediate layer 160 corresponds to the "second plane." The bottom surface 161a is provided in a part of the intermediate layer 160. In this embodiment, the bottom surface 161a is provided radially outward from the main lumen 140.

[0059] In this embodiment, the bottom surface 161a of the first recess 161 formed in the intermediate layer 160 is formed to be flat. On the other hand, the first sub-lumen tube 143 has an oval shape, and the opposing surface 143a is formed to be flat. The bottom surface 161a of the first recess 161 formed in the intermediate layer 160 and the opposing surface 143a of the first sub-lumen tube 143 are in contact with each other.

[0060] In this embodiment, the intermediate layer 160 and the first sub-lumen tube 143 are bundled together by a reinforcing wire 148. If the intermediate layer 160 and the first sub-lumen tube 143 were both circular, the first sub-lumen tube 143 would move on the surface of the intermediate layer 160 when bundled together by the reinforcing wire 148, and the position of the first sub-lumen tube 143 might deviate from its designed position (i.e., the position where the first sub-lumen 142 and the second sub-lumen 144 are 180 degrees opposed to each other across the center C). By making the bottom surface 161a of the first recess 161 formed in the intermediate layer 160 and the opposing surface 143a of the first sub-lumen tube 143 flat as in this embodiment, the first sub-lumen tube 143 is stabilized on the surface of the intermediate layer 160, making it less likely that the first sub-lumen tube 143 will deviate from its designed position when bundled together by the reinforcing wire 148. The same is true for the second sub-lumen tube 145. Therefore, according to the catheter shaft 120 of this embodiment, the first sub-lumen 142 and the second sub-lumen 144 can be arranged at the designed positions, thereby improving planarity.

[0061] 9, side surfaces 161b and 161c of first recess 161 may be in contact with side surfaces 143b and 143c of first sub-lumen tube 143. In this case, first sub-lumen tube 143 can be positioned more accurately at the designed position.

[0062] At least a portion of the bottom surface 161a of the first recess 161 formed in the intermediate layer 160 may be flat, but it is preferable that the entire bottom surface 161a is flat, as shown in Fig. 9. Furthermore, at least a portion of the opposing surface 143a of the first sublumen tube 143 may be flat, but it is preferable that the entire opposing surface 143a is flat, as shown in Fig. 9.

[0063] In the catheter shaft 120 according to this embodiment, the intermediate layer 160 has a flat surface that comes into contact with the first sub-lumen tube 143, and therefore the main lumen 140 can be made circular, unlike the catheter shaft 20 shown in Fig. 2. Since the main lumen 140 does not have a minimum inner diameter, it becomes possible to insert a device with a large outer diameter through the main lumen 140.

[0064] In the catheter shaft 120 according to this embodiment, the distance from the center C to the outermost surface 143d of the first sub-lumen tube 143 may be approximately the same as the distance from the center C to the outermost surface 160a of the intermediate layer 160. In this case, the cross-sectional shape of the reinforcing wire 148 may be circular. When the cross-sectional shape of the reinforcing wire 148 is circular, the torque transmissibility of the catheter shaft 120 can be improved compared to when the cross-sectional shape is non-circular as shown in FIG. 2 .

[0065] In the catheter shaft 120 according to this embodiment, the hardness of the intermediate layer 160 can be varied depending on the region, thereby homogenizing the rigidity of the catheter shaft 120 in a cross section perpendicular to the axial direction, thereby suppressing the anisotropy of the catheter shaft 120. As a result, torque transmission can be improved compared to the catheter shaft 20 shown in Figure 2.

[0066] Figure 10 shows a catheter shaft 220 according to a modified example. In the catheter shaft 220 shown in Figure 10, instead of forming a recess in the intermediate layer 160 as in the catheter shaft 120 shown in Figure 9, a portion of the intermediate layer 160 is cut to form a surface 210 facing the first sub-lumen tube 143. This facing surface 210 is formed as a flat surface (corresponding to the second flat surface). The facing surface 143a of the first sub-lumen tube 143 is also formed as a flat surface. The first sub-lumen tube 143 is positioned so that its facing surface 143a contacts the facing surface 210 of the intermediate layer 160.

[0067] In the catheter shaft 220 according to this modification, by making the opposing surface formed on the intermediate layer 160 and the opposing surface 143a of the first sub-lumen tube 143 flat, the first sub-lumen tube 143 is stabilized on the surface of the intermediate layer 160, making it less likely that the first sub-lumen tube 143 will shift from its designed position when bundled with the reinforcing wire 148. The same is true for the second sub-lumen tube 145. Therefore, with the catheter shaft 220 according to this modification, the first sub-lumen 142 and the second sub-lumen 144 can be positioned in their designed positions, improving planarity.

[0068] Certain aspects of the present invention are as follows. (Item 1) A catheter shaft comprising: a main lumen tube forming a main lumen; and a sub-lumen tube forming a sub-lumen, wherein a first flat surface is provided on a portion of the sub-lumen tube; and a second flat surface is provided radially outward from the main lumen, and the sub-lumen tube is disposed so that the first flat surface is in contact with the second flat surface. (Item 2) The catheter shaft according to Item 1, wherein the second flat surface is provided on a portion of the main lumen tube. (Item 3) The catheter shaft according to Item 2, wherein the width of the sub-lumen is within 30% to 90% of the width of the second flat surface of the main lumen tube. (Item 4) The catheter shaft according to Item 2 or 3, further comprising a reinforcing wire bundling the main lumen tube and the sub-lumen tube. (Item 5) The catheter shaft according to Item 4, wherein the catheter shaft comprises an outer layer provided so as to cover the main lumen tube, the sub-lumen tube, and the reinforcing wire, and wherein the height of the sub-lumen is within 30% of the thickness of the outer layer. (Item 6) The catheter shaft according to any one of Items 2 to 5, wherein the main lumen has a substantially circular shape, and the distance from the center of the main lumen to the opposing surface of the main lumen tube is 80% or more of the radius of the main lumen. (Item 7) The catheter shaft according to any one of Items 2 to 6, wherein the height of the sub-lumen is substantially uniform from one end to the other end. (Item 8) The catheter shaft according to Item 1, further comprising an intermediate layer provided so as to cover the main lumen tube, and wherein the second flat surface is provided on a part of the intermediate layer. (Item 9) The catheter shaft according to Item 8, further comprising a reinforcing wire bundling the intermediate layer and the sub-lumen tube. (Item 10) The catheter shaft according to Item 9, further comprising an outer layer provided so as to cover the intermediate layer, the sub-lumen tube, and the reinforcing wire.(Item 11) A catheter comprising: the catheter shaft according to any one of Items 1 to 10; a manipulation wire inserted through the sub-lumen; and a manipulation section provided at the proximal end of the catheter shaft for pulling the manipulation wire.

[0069] The above-described embodiments and variations are merely examples. The abstract technical concepts should not be interpreted as being limited to the contents of the embodiments and variations. Many design changes are possible in the contents of the embodiments and variations, such as changes, additions, and deletions of components. In the above-described embodiments, the term "embodiment" is used to emphasize the contents in which such design changes are possible. However, design changes are also permitted even in contents without such notation. Hatching on cross sections in the drawings does not limit the materials of the hatched objects. The structures and numerical values ​​referred to in the embodiments and variations naturally include those that can be considered identical when manufacturing errors, etc. are taken into account.

[0070] The present invention relates to a catheter with a deflectable tip.

[0071] 10 Catheter, 20, 120, 220 Catheter shaft, 28 Distal end, 30 Operation section, 31 Handle, 32 Rotating plate, 40, 140 Main lumen, 41, 141 Main lumen tube, 42, 142 First sub-lumen, 43, 143 First sub-lumen tube, 44, 144 Second sub-lumen, 45, 145 Second sub-lumen tube, 46, 146 First operation wire, 47, 147 Second operation wire, 48, 148 Reinforcing wire, 49, 149 Outer layer, 50 Main lumen core material, 51 Sub-lumen core material, 160 Intermediate layer.

Claims

1. A catheter shaft comprising: a main lumen tube that forms a main lumen; and a sub-lumen tube that forms a sub-lumen, wherein a first flat surface is provided on a portion of the sub-lumen tube; and a second flat surface is provided radially outward from the main lumen, and the sub-lumen tube is positioned so that the first flat surface is in contact with the second flat surface.

2. The catheter shaft according to claim 1, wherein the second plane is provided on a portion of the main lumen tube.

3. The catheter shaft according to claim 2, wherein the width of the sub-lumen is within 30% to 90% of the width of the second plane of the main lumen tube.

4. The catheter shaft according to claim 2, further comprising a reinforcing wire bundling the main lumen tube and the sub-lumen tube.

5. The catheter shaft according to claim 4, further comprising an outer layer provided to cover the main lumen tube, the sub-lumen tube and the reinforcing wire, wherein the height of the sub-lumen is within 30% of the thickness of the outer layer.

6. The catheter shaft according to claim 2, wherein the main lumen has a substantially circular shape, and the distance from the center of the main lumen to the opposing surface of the main lumen tube is 80% or more of the radius of the main lumen.

7. The catheter shaft according to claim 2, wherein the height of said sub-lumen is substantially uniform from one end to the other.

8. The catheter shaft according to claim 1, further comprising an intermediate layer provided so as to cover the main lumen tube, and the second plane is provided on a part of the intermediate layer.

9. The catheter shaft according to claim 8, further comprising a reinforcing wire binding the intermediate layer and the sub-lumen tube.

10. The catheter shaft according to claim 9, further comprising an outer layer provided to cover the intermediate layer, the sub-lumen tube and the reinforcing wire.

11. A catheter comprising: a catheter shaft according to any one of claims 1 to 10; a control wire inserted through the sub-lumen; and a control section provided at the base end of the catheter shaft for pulling the control wire.

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