conduit

Abstract

The present invention aims to provide a catheter of an asymmetric bending type, which has different bending shapes of a catheter distal portion bent to one side and a catheter distal portion bent to the other side. The catheter has a shaft, a first wire and a second wire, a leaf spring configured to separate an inner lumen of the shaft into a first portion in which the first wire is disposed and a second portion in which the second wire is disposed, a support member, and a first coil having an inner lumen in which the first wire is disposed, the first coil being fixed to a proximal end side of the leaf spring at at least two points, the first coil having an overall length L1 in a natural state and an overall length L2 at a maximum compression C1 , and a ratio L C1 / L1 of 0.9 or more.

Description

Technical Field

[0001] This invention relates to a conduit with a flexible tip. Background Technology

[0002] Electrode catheters with multiple electrodes at their distal end are used to measure cardiac potentials or to perform pacing. Among such electrode-equipped catheters, some allow the distal end to be bent via a handle for easy placement at the desired location within the heart. Such catheters are typically bent by pulling a drawstring fixed to the inside of the catheter's tip. Furthermore, catheters with two drawstrings have been proposed to allow bending of the catheter to one or both sides along its length.

[0003] For example, Patent Document 1 discloses a catheter with a deflectable tip, which includes multiple operating tubes with an operating line disposed inside the catheter's lumen. These operating tubes are divided into multiple partial tubes, allowing the tip of the catheter to be deformed into a smooth, curved shape that does not bend midway. Furthermore, patent documents 2 and 3 have also been proposed that allow the tip to deflect even when the tip of the catheter is bent, preventing the tip electrode, a leaf spring disposed inside the tip of the catheter, and the pull line from detaching. Additionally, patent documents 4 and 5 have also been proposed that allow the tip to deflect even when bent, preventing the tip electrode, the leaf spring disposed inside the tip of the catheter, and the pull line from detaching.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2012-200445

[0005] Patent Document 2: Japanese Patent Application Publication No. 2010-75530

[0006] Patent Document 3: Japanese Patent Application Publication No. 2015-100515

[0007] Patent Document 4: Japanese Patent Application Publication No. 2012-147971

[0008] Patent Document 5: Japanese Patent Publication No. 2017-518122

[0009] To match the size of the heart and deliver the distal portion of the catheter to the most suitable location, an asymmetrical curved type of catheter is required. This type of catheter not only allows the distal portion to bend to either side, but also allows each bend to have a different diameter. Furthermore, by increasing the degree of asymmetry in the bend, it is easier to deliver the distal portion of the catheter to the desired location. However, in the structures of Patent Documents 4 and 5, it is difficult to form catheters with a higher degree of asymmetry in the bend diameter. Summary of the Invention

[0010] The present invention was made in view of the above circumstances, and its object is to provide an asymmetrical bending type catheter, wherein the distal portion of the catheter can be bent to either side, and the bending shape is different for each side.

[0011] The catheter capable of solving the above-mentioned problems is characterized by having: a shaft having a distal end and a proximal end, and having an inner cavity extending along the length direction; a first line and a second line having a distal end and a proximal end, the distal end being fixed to the distal end of the shaft, the proximal end being disposed at the proximal end of the shaft, the first line and the second line extending within the inner cavity of the shaft; a leaf spring disposed within the inner cavity of the shaft to separate the inner cavity of the shaft along the length direction into a first part for the first line and a second part for the second line; and a support member extending along the length direction, having an inner cavity for the first line and the second line, the support member fixing the proximal end of the leaf spring. The support member is positioned closer to the leaf spring than the leaf spring; and a first coil has an inner cavity for arranging a first wire and is positioned distally from the distal end of the support member within a first portion. The first coil is fixed to the proximal end of the leaf spring at at least two points. The first coil has a first fixing portion that serves as a part fixing the first coil to the leaf spring, a second fixing portion located closer to the leaf spring than the first fixing portion and also serving as a part fixing the first coil to the leaf spring, and an intermediate non-fixed portion located between the first and second fixing portions and serving as a part not fixed to the leaf spring. The first coil has a total length L1 in its natural state and a total length L2 under maximum compression. C1 Their ratio L C1 / L1 is above 0.9.

[0012] The preferred support component is a proximal side tube.

[0013] The first coil is preferably uncompressed.

[0014] Preferably, the portion where the first coil is fixed to the leaf spring is located on the side of the first coil facing the leaf spring.

[0015] Preferably, the non-fixed portion of the first coil, that is, the longest non-fixed portion in the length direction, is configured such that its length in the natural state in the length direction is more than 50% of the total length L1 of the first coil in the natural state.

[0016] Preferably, the first coil has a distal non-fixed portion between the distal end of the first coil and the first fixed portion, and the distal non-fixed portion does not have a fixed portion for fixing the first coil to the leaf spring.

[0017] Preferably, a second coil is further provided, the second coil having an inner cavity for the first coil to be arranged, and being arranged in the first part at a position more distal than the first coil.

[0018] In this case, it is preferable that the second coil has a total length L2 in its natural state and a total length L under maximum compression. C2 L C2 / L2 is less than 0.9.

[0019] Preferably, the bending stiffness of the first coil is greater than that of the second coil, and the difference between the bending stiffness of the first coil and the bending stiffness of the second coil is less than 50%.

[0020] Preferably, the first coil comprises a first coil wire wound in a spiral shape, and the second coil comprises a second coil wire wound in a spiral shape, wherein the pitch interval of the first coil is smaller than the pitch interval of the second coil.

[0021] Preferably, the wire diameter and coil diameter of the first coil are the same as those of the second coil.

[0022] Preferably, a third coil is further provided, the third coil having an inner cavity for the second wire to be arranged, and is arranged in the second part.

[0023] Preferably, the third coil has a total length L3 in its natural state and a total length L under maximum compression. C3 L C3 / L3 is less than 0.9.

[0024] Preferably, a second coil is provided, the second coil having an inner cavity for the first wire to be arranged, and being arranged in the first part at a position further away from the first coil. A third coil is provided, the third coil having an inner cavity for the second wire to be arranged, and being arranged in the second part. Furthermore, a protective tube is provided, the protective tube having an inner cavity and being arranged inside the shaft cavity. A leaf spring, the first coil, the second coil, and the third coil are arranged in the inner cavity of the protective tube.

[0025] Preferably, the first coil is fixed to the first fixing part and the second fixing part by welding, bonding or pressing.

[0026] According to the present invention, an asymmetrical bending type catheter can be provided, wherein the distal portion of the catheter can be bent to either side or to the other side, and the bending shape is different for each side, so that the distal portion of the catheter can be easily delivered to the desired location. Attached Figure Description

[0027] Figure 1 A top view of a catheter according to one embodiment of the present invention.

[0028] Figure 2 A top view of a catheter according to one embodiment of the present invention.

[0029] Figure 3 A top view of a catheter according to one embodiment of the present invention.

[0030] Figure 4express Figure 2 The diagram shows a cross-sectional view of the distal portion of the catheter along its length.

[0031] Figure 5 express Figure 4 The image shows a V-V sectional view of the distal portion of the catheter.

[0032] Figure 6 express Figure 4 The diagram shows a VI-VI sectional view of the distal portion of the catheter.

[0033] Figure 7 express Figure 4 The diagram shows a sectional view VII-VII of the distal portion of the catheter.

[0034] Figure 8 express Figure 4 The side view inside the axis of portion A of the distal part of the catheter shown.

[0035] Figure 9 A side view showing the first coil according to one embodiment of the present invention.

[0036] Figure 10 express Figure 9 The side view of the first coil at maximum compression is shown.

[0037] Figure 11 A side view showing the first coil according to another embodiment of the present invention.

[0038] Figure 12 A cross-sectional view along the length of the distal portion of the catheter in another embodiment of the present invention.

[0039] Figure 13 A cross-sectional view along the length of the distal portion of the catheter according to yet another embodiment of the present invention.

[0040] Figure 14 Methods for determining rigidity.

[0041] Figure 15 express Figure 4 Other examples of V-V cross-sectional views of the distal portion of the catheter shown. Detailed Implementation

[0042] The present invention will now be described based on embodiments, but it is not limited to these embodiments. Appropriate modifications and implementations can be made within the scope of the above and following descriptions, and all such modifications are included within the technical scope of the present invention. Furthermore, for convenience, section lines and component reference numerals may be omitted in the accompanying drawings; in such cases, please refer to the specification and other drawings. Additionally, the dimensions of various components in the drawings are primarily helpful in understanding the features of the present invention, and therefore may differ from the actual dimensions.

[0043] The catheter of the present invention comprises: a shaft having a distal end and a proximal end, and having an inner cavity extending along the length direction; a first line and a second line having a distal end and a proximal end, the distal end being fixed to the distal end of the shaft, and the proximal end being disposed at the proximal end of the shaft, the first line and the second line extending within the inner cavity of the shaft; a leaf spring disposed within the inner cavity of the shaft to separate the inner cavity of the shaft along the length direction into a first portion for the first line and a second portion for the second line; and a support member extending along the length direction, having an inner cavity for the first line and the second line, the support member fixing the proximal end of the leaf spring. The first coil is positioned closer to the leaf spring than the leaf spring; and a first coil having an inner cavity for arranging the first wire, and positioned further to the distal end of the support member within the first part. The first coil is fixed to the proximal end of the leaf spring at at least two points. The first coil has a first fixing portion that serves as a part fixing the first coil to the leaf spring, a second fixing portion located closer to the leaf spring than the first fixing portion and also serving as a part fixing the first coil to the leaf spring, and an intermediate non-fixed portion located between the first and second fixing portions and serving as a part not fixed to the leaf spring. The first coil has a total length L1 in its natural state and a total length L2 under maximum compression. C1 Their ratio L C1 / L1 is above 0.9.

[0044] With the above-described structure, the catheter of the present invention can be formed into an asymmetrically curved type, wherein the distal portion of the catheter can be bent radially towards both one side and the other side of the leaf spring, and the bending shape when bending towards one side of the leaf spring is different from the bending shape when bending towards the other side of the leaf spring. Therefore, the catheter of the present invention can easily deliver the distal portion of the catheter to the desired location in the blood vessel or heart. The difference in bending shape refers to the difference between the shape when bending to one side and the shape when bending to the other side, including the case where the size of the circle formed by the bending shape is different, in other words, the radius is different. According to the present invention, the difference in curve shape, especially the difference in size, between the bending shape on one side and the bending shape on the other side can be further increased, thus enabling the adaptation to various shapes of blood vessel curves.

[0045] The following is for reference Figures 1-15 The catheter according to an embodiment of the present invention will be described. Figures 1-3 The diagram shows a top view of a catheter according to one embodiment of the present invention. The dashed lines indicate the shape of the distal portion of the catheter when it is bent radially toward one side and the other side of the leaf spring. Figure 2 The dashed line indicates the distal portion of the catheter and... Figure 1 The situation shown is a comparison with what it looks like when it is further bent. Figure 3 The dashed line indicates the distal portion of the catheter and... Figure 2 The situation shown is a comparison with what it looks like when it is further bent. Figure 4 express Figure 2 The diagram shows a cross-sectional view of the distal portion of the catheter along its length. The dashed lines indicate how the distal portion of the catheter bends radially toward one side and the other side of the leaf spring. Figures 5-7 They represent Figure 4 The diagram shows the V-V, VI-VI, and VII-VII sectional views of the distal portion of the catheter.

[0046] Figure 8 express Figure 4 The side view of the distal portion A of the catheter, showing the first and second lines, leaf spring, support member, and first coil arranged in the inner cavity of the shaft. Figure 9 A side view showing the first coil in its natural state according to an embodiment of the present invention. Figure 10 express Figure 9 The side view of the first coil at maximum compression is shown. Figure 11 A side view showing the first coil in its natural state according to another embodiment of the present invention. Figure 12 A cross-sectional view along the length of the distal portion of the catheter in another embodiment of the present invention, with dashed lines indicating how the distal portion of the catheter is bent radially toward one side and the other side of the leaf spring. Figure 13 This is a cross-sectional view along the length of the distal portion of the catheter, representing yet another embodiment of the invention. The dashed lines indicate how the distal portion of the catheter is bent radially toward one side and the other side of the leaf spring. Figure 14 Methods for determining rigidity. Figure 15 express Figure 4 Other examples of V-V cross-sectional views of the distal portion of the catheter shown.

[0047] In this invention, the proximal side refers to the side located at the user's hand's side relative to the extension direction of the axis, and the distal side refers to the side opposite to the proximal side, i.e., the side of the object being treated. Furthermore, the extension direction of the axis is referred to as the length direction d. L Radial d R This refers to the radial direction, which is perpendicular to the direction of the axis's extension. Figures 1-4 , Figure 8 , Figure 12 and Figure 13 In the diagram, the lower side is the proximal side, and the upper side is the distal side. Additionally, in... Figures 1-4 , Figure 8 , Figure 12 and Figure 13 In the diagram, the left side represents the radial direction d of the axis. R One side of the leaf spring, the right side of the figure shows the radial direction d of the shaft. R The other side of the leaf spring.

[0048] like Figures 1-3 As shown, the catheter 1 has a shaft 2, which has a distal end and a proximal end, and has a length direction d. L An extended inner cavity. A front end portion 20 is preferably disposed at the distal end of the shaft 2, and a handle 7 is preferably disposed at the proximal end of the shaft 2.

[0049] The shaft 2 is inserted into the body from its distal end and delivered to the treatment site. Therefore, it is preferably flexible, and materials such as metal or resin can be used. Since it is inserted into the body, biocompatible materials are preferred. Electrodes, sensors, and other therapeutic devices can be disposed on the surface of the shaft 2. The presence of electrodes on the surface of the shaft 2 allows it to be used as an electrode catheter for measuring cardiac potential or an ablation catheter for cauterizing tissue.

[0050] The inner cavity of shaft 2 can be configured with internal structures for bending the catheter, or with devices for treatment such as sensors or wires. The inner cavity of shaft 2 can be a single cavity or may partially have multiple cavities. The bending structure of the present invention is configured in a single cavity. For example, to bend the distal portion 2D of the catheter 1, the bent portion can be a single cavity, while multiple cavities can be located closer to it. The cavity can also be a double-layered structure. The longitudinal direction d of the shaft... L The length, outer diameter, thickness, etc., can be selected to create an appropriate size for treatment.

[0051] A front end portion 20 is preferably disposed at the distal end of the shaft 2. The front end portion 20 may be a component different from or the same as the shaft 2. When the front end portion 20 is a component different from the shaft 2, it may also have a portion that is inserted into the cavity of the shaft 2 or a portion that protrudes distally from the distal end of the shaft. When the front end portion 20 is the same as the shaft 2, the opening at the distal end of the shaft 2 may be blocked by means of heat welding or the like, thereby forming the front end portion 20.

[0052] A handle 7 is preferably disposed proximally to the shaft 2, and the proximal end of the shaft 2 is preferably fixed inside the handle 7. A guide wire and an operating line extending from the inner cavity of the shaft 2 are disposed within the handle 7. For ease of operation of the operating line, the handle 7 may also include a line operating section 70. By fixing the proximal end of the operating line to the line operating section 70, the line operating section 70 can be operated to pull the line, thereby bending the distal end of the catheter 1.

[0053] like Figures 4-7As shown, the catheter 1 is disposed within the lumen of the shaft 2 as follows: a first wire 41 and a second wire 42, each having a distal end and a proximal end, the distal end being fixed to the distal end of the shaft 2, for example, the anterior end 20, and the proximal end being disposed at the proximal end of the shaft 2, for example, the handle 7; the first wire 41 and the second wire extend within the lumen of the shaft 2 (e.g., from the anterior end 20 to the handle 7); and a leaf spring 30, having a distal end and a proximal end, and configured to extend along the length direction d. L The inner cavity of shaft 2 is divided into a first part 21 for the first line 41 and a second part 22 for the second line 42; and a support member 60 having a distal end and a proximal end along the length direction d. L The extension has an inner cavity for the first line 41 and the second line 42 to be arranged. The support member 60 fixes the proximal end of the leaf spring 30. The support member 60 is arranged at a position closer to the position side than the leaf spring 30.

[0054] The first wire 41 and the second wire 42 are operating wires used for bending the distal portion 2D of the catheter 1. The first wire 41 and the second wire 42 are preferably disposed within the inner cavity of the shaft 2, with the distal end fixed to the front end 20 and the proximal end fixed to the handle 7. The first wire 41 and the second wire 42 can be made of metal wire such as stainless steel or synthetic resin such as fluoropolymer. The first wire 41 and the second wire 42 can each be a single wire, or they can be constructed from multiple wires.

[0055] The leaf spring 30 is a component that defines the bending direction of the conduit 1, and is configured within the cavity of the shaft 2 in the longitudinal direction d. L The inner cavity of shaft 2 is divided into a first part 21 for the first wire 41 and a second part 22 for the second wire 42. The proximal end of leaf spring 30 is fixed to support member 60. The distal end of leaf spring 30 is preferably fixed to the distal end of shaft 2. When a front end 20 is provided at the distal end of shaft 2, it is preferable to fix it to the front end 20. The distal end of leaf spring 30 may also not be fixed. The distal and proximal ends of leaf spring 30 may not be fixed by directly fixing the ends, but by fixing the vicinity of them. The method of fixing the distal and proximal ends of leaf spring 30 is not particularly limited, but examples include brazing, fusion welding, bonding with adhesives, riveting, etc. When the front end 20 and support member 60 are metal, it is preferable to fix them by laser welding.

[0056] The leaf spring 30 has a distal end and a proximal end, and is oriented along the length direction d. LThe leaf spring 30 is preferably arranged along the length axis of the shaft 2. Thus, the leaf spring 30 divides the inner cavity of the shaft 2 into two parts: a first part 21 on one side encompassing the length axis of the shaft 2 and a second part 22 on the other side. A first thread 41 is arranged on the first part 21 of the divided inner cavity of the shaft 2, and a second thread 42 is arranged on the second part 22. The surface of the leaf spring 30 on the side where the first thread 41 is arranged is designated as the first surface 31, and the surface of the leaf spring 30 on the side where the second thread 42 is arranged is designated as the second surface 32. The first surface 31 of the leaf spring 30 can be referred to as one surface, and the second surface 32 can be referred to as another surface.

[0057] The leaf spring 30 is a spring that uses sheet metal. Materials constituting the leaf spring 30 can include metals such as stainless steel, titanium, carbon steel, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy. Alternatively, materials constituting the leaf spring 30 can include synthetic resins such as aromatic polyetherketone resin (e.g., PEEK), polycarbonate resin, and fiber-reinforced resin. Furthermore, the leaf spring 30 can also be made of synthetic rubbers or natural rubbers such as butadiene rubber, isoprene rubber, styrene-butadiene rubber, ethylene propylene rubber, acrylic rubber, and silicone rubber. In particular, stainless steel is preferred as the material for the leaf spring 30.

[0058] The support member 60 is disposed proximal to the leaf spring 30 within the cavity of the shaft 2, and a first wire 41 and a second wire 42 are disposed within its cavity. The proximal end of the leaf spring 30 is fixed to the distal end of the support member 60. The proximal end of the support member 60 may extend to the proximal end of the shaft 2, or it may be disposed midway along the shaft 2. The support member 60 may also be replaced with different components, such as a tube, midway along the shaft 2.

[0059] The support member 60 can also be a proximal tube with a cylindrical shape. If the support member 60 is a proximal tube, the proximal tube can receive the proximal end of the leaf spring 30, so that a portion of the leaf spring 30 is disposed within the cavity of the proximal tube. This makes the fixation between the leaf spring 30 and the support member 60 more secure.

[0060] The support member 60 preferably has the same flexibility as the shaft 2, and can be made of metal or resin. In particular, a coil made of wound metal wire is preferred. The conduit 1 of the present invention switches its internal structure at the distal end of the support member 60, so it is preferable to select the size, flexibility, and material of the support member 60 in such a way that the change in the stiffness of the conduit 1 is not greater on the distal side and proximal side of the support member 60 than on the distal end.

[0061] The leaf spring 30 of the conduit 1 of the present invention can be bent from the portion exposed at the distal end of the support member 60 to the distal end, such as the front end portion 20, where the leaf spring 30 is fixed to the shaft 2. Therefore, the length of the bent portion of the conduit 1 can be appropriately set according to the length of the leaf spring 30 and the position where the front end portion 20 or the support member 60 is fixed to the leaf spring 30. Preferably, the support member 60 does not deform simply with the bending of the leaf spring 30.

[0062] like Figure 4 As shown, the conduit 1 includes a first coil 51, which has an inner cavity for arranging the first wire 41 and is positioned distal to the distal end of the support member 60. The first coil 51 is disposed on the proximal end side of the leaf spring 30 and is fixed to the proximal end side of the leaf spring 30 at least in two places. "Disposed on the proximal end side of the leaf spring 30" means disposed on the portion of the leaf spring near the proximal end, i.e., the proximal end of the first coil 51 is positioned adjacent to or close to the distal end of the support member 60. The first coil 51 is a component that restricts the bending of the leaf spring 30 toward one surface 31; therefore, if the first coil 51 is fixed to the distal side of the leaf spring 30, the leaf spring 30 becomes unable to bend toward one surface 31. The first coil 51 has: a first fixing part 511 which serves as the part that fixes the first coil 51 to the leaf spring 30; a second fixing part 512 located closer to the side than the first fixing part; and an intermediate non-fixed part 510m located between the first fixing part 511 and the second fixing part 512 and serving as the part that is not fixed to the leaf spring 30.

[0063] The first coil 51 can be made of metal wire such as stainless steel or nickel-titanium alloy, or synthetic resin wire such as aromatic polyetherketone resin (e.g., PEEK) or polycarbonate resin. The cross-sectional shape of the wire forming the first coil 51 can be circular, quadrilateral, or a combination thereof. In particular, it is preferred that the first coil 51 is a metal coil made of stainless steel wire with a circular cross-section. The wire diameter, coil diameter, and length of the first coil 51 can be appropriately selected as needed.

[0064] The first coil 51 and the leaf spring 30 are preferably fixed by welding, bonding, or pressing. In particular, fixing by welding is preferred. If fixing is done by welding, the first fixing part 511 and the second fixing part 512 can be formed without the use of materials such as solder and adhesive.

[0065] The fixing of the first coil 51 to the leaf spring 30 can be a direct fixing of the first coil 51 to the leaf spring 30, a fixing based on the contact between the proximal end of the first coil 51 and the support member 60, or an indirect fixing of the first coil 51 to the support member 60 by welding, bonding, or pressing. The second fixing part 512 can also be a fixing part that is fixed by contact between the proximal end of the first coil 51 and the support member 60, or the second fixing part 512 can also be a state in which the first coil 51 to the support member 60 is fixed by welding, bonding, or pressing to indirectly fix the first coil 51 to the leaf spring 30.

[0066] The length direction d of the first fixing part 511 and the second fixing part 512 L The position of the fixing part 51 is not particularly limited and can be arranged at any position on the surface of the first coil 51. For example, the first fixing part 511 can be arranged at the distal end of the first coil 51, and the second fixing part 512 can be arranged at the proximal end of the first coil 51. In addition, although not shown, in addition to the first fixing part 511 and the second fixing part 512, there may be further fixing parts. The total number of fixing parts is two or more, and there may be more than two fixing parts. By providing at least two fixing parts, the first coil 51 can be fixed to the leaf spring 30 in such a way that the leaf spring 30 on the proximal side does not bend from the fixing part on the farthest side toward one surface 31. In order to prevent the difference in rigidity between the part of the shaft 2 where the first coil 51 is arranged and the other parts from being too large, it is preferable to have two fixing parts.

[0067] The first coil 51, including the first fixing part 511 and the second fixing part 512, and the fixing part of the leaf spring 30 in the longitudinal direction d L The length of the upper part can be set appropriately, but it is preferable that the length direction d of the fixing part is longer. L The length on is relatively short, such as Figure 8 As shown, for example, the preferred length is approximately the length of three wires forming the coil. If the length direction d of the fixing part... L If the length is long, there is a concern that the flexibility of the catheter 1 may be lost when it bends to the other side 32.

[0068] like Figures 9-10 As shown, the first coil 51 has a total length L1 in its natural state and a total length L2 in its maximum compression state. C1 Their ratio L C1 / L1 is 0.9 or higher. Additionally, the first coil 51 is preferred. Figure 11 The diagram shows the uncompressed coil. Here, in this invention, the uncompressed coil is a closely wound coil, that is, in the length direction d... L The total length L1 of the coil in its natural state (not compressed) and the total length L of the coil in its maximum compressed state. C1 The ratio of LC1 / L1 is a coil of 1, but L C1 When L1 is 0.9 or higher, or 0.95 or higher, it is also considered uncompressed and is included in the uncompressed coil. To improve the uncompressibility of the first coil 51, L is preferred. C1 / L1 is above 0.95.

[0069] By forming the structure of the present invention, the distal portion 2D of the conduit 1 can be bent to either side, and the bending shapes can be different. In particular, the bending diameters can be different, and the different bending diameters can be strictly controlled. When the first line 41 of the first portion 21 disposed in the inner cavity of the shaft 2 is pulled, that is, when the first line 41 disposed on one side of the leaf spring 30, the leaf spring 30 bends towards the side of the surface 31, and with this, the distal portion 2D of the conduit 1 bends towards the side of the surface 31. On the proximal side of the leaf spring 30, the first coil 51 is fixed to the leaf spring 30 at least at two points, and the first coil 51 is an uncompressed coil, so the first coil cannot bend towards the side without the leaf spring 30, that is, towards the surface 31. This is because the uncompressed coil is fixed at two points, so between these two points, the first coil 51 cannot be compressed relative to bending towards one surface, but functions as a rigid tube. Therefore, only the portion of the leaf spring 30 between the part fixed to the front end 20 and the fixing part at the farthest side of the first coil 51 can be bent to one side.

[0070] If the leaf spring 30 and the first coil 51 are fixed at only one point, the first coil 51 can bend towards one face 31 along with the bending of the leaf spring 30. Alternatively, if the first coil 51 is not a non-compressed coil, the coil can extend relative to both one face and the other, thus also being able to bend towards one face. Therefore, regardless of whether the first coil 51 and the leaf spring 30 are fixed at two points or are non-compressed, the leaf spring 30 can bend towards one face 31 within a range from the distal to the proximal side.

[0071] On the other hand, when the second wire 42 of the second part 22 disposed in the inner cavity of the shaft 2 of the conduit 1 is pulled, in other words, when the second wire 42 disposed on the other side 32 of the leaf spring 30 is pulled, the leaf spring 30 bends towards the other side 32, and at the same time, the distal part 2D of the shaft of the conduit 1 bends towards the other side 32. The first coil 51 disposed on one side 31 of the leaf spring 30 is able to bend towards the other side 32 as the non-fixed part of the coil on one side of the coil bends due to the increased spacing of the bare wires of the coil. Therefore, the entire portion of the leaf spring 30 from the part fixed to the front end 20 to the distal end of the support member 60 can bend towards the other side 32.

[0072] The portion that fixes the first coil 51 to the leaf spring 30 is preferably located on one side 31 of the first coil 51 facing the leaf spring 30. This does not impede the bending of the first coil 51 toward the leaf spring 30, i.e., toward the other side 32.

[0073] The portion of the first coil 51 without a fixed part between the first fixing part 511 and the second fixing part 512, i.e., the intermediate non-fixed part 510m, preferably along the length direction d. L The length in its natural state is at least 50% of the total length L1 of the first coil 51 in its natural state. In the case of having multiple intermediate non-fixed portions 510m, the length direction d of the longest intermediate non-fixed portion 510m is preferably […]. L The length of the first coil 51 in its natural state is more than 50% of the total length L1 of the first coil 51 in its natural state. By ensuring that the intermediate non-fixed portion 510m is relatively long, it is possible to prevent the first coil 51 from bending towards one face 31 without hindering bending towards the other face 32. Furthermore, the length of the longest intermediate non-fixed portion 510m of the first coil 51 can be configured such that the length direction d L The length of the first coil 51 in its natural state is more than 30% of the total length L1 of the first coil 51 in its natural state, and can be more than 20%. Even within this range, it is possible to prevent the first coil 51 from bending towards one face 31 without hindering bending towards the other face 32. In particular, when the fixed portion on the far side of the longest intermediate non-fixed portion 510m is close to the far side of the first coil 51, even if the length direction d of the longest intermediate non-fixed portion 510m is... L The length of the coil in its natural state is less than 50% of the total length L1 of the first coil 51 in its natural state, which can also effectively prevent the first coil 51 from bending toward one side 31.

[0074] By controlling the position of the fixing part of the first coil 51, the bending shape of the distal side of the conduit 1 can be controlled. This is because the bending towards one side 31 is formed by the portion between the fixing part at the distal end of the shaft 2 of the first line 41 and the fixing part at the farthest side of the first coil 51, while the bending towards the other side 32 is formed by the portion between the fixing part at the distal end of the shaft 2 of the second line 42 and the distal end of the support member 60.

[0075] Preferably, the first coil 51 does not have a fixing portion between its distal end and the first fixing portion 511 that secures the first coil 51 to the leaf spring 30. By having such a distal non-fixed portion 510d between the distal end of the first coil 51 and the fixing portion at the farthest end, it is possible to prevent the bending shape from changing extremely between a bendable portion further distal to the first coil 51 and a portion that does not bend toward one surface 31 closer to the fixing portion at the farthest end of the first coil 51. For example, if the fixing portion at the farthest end of the first coil 51 is located at the distal end of the first coil 51, there is a concern that the conduit 1 may bend at the distal end of the first coil 51.

[0076] like Figure 12 As shown, the conduit 1 may further include a second coil 52. The second coil 52 has an inner cavity for the first coil 41 to be disposed, and is disposed in the inner cavity of the shaft 2 at a position more distal than the first coil 51 than the first coil 51, in the first part 21 separated by the leaf spring 30. The second coil 52 may also contact any part of the leaf spring 30, etc., in the inner cavity of the shaft 2, but preferably no part is fixed.

[0077] like Figure 12 As shown, the conduit 1 may further include a third coil 53. The third coil 53 has an inner cavity for the second wire 42 to be disposed, and a second part 22 separated by the leaf spring 30 is disposed in the inner cavity of the shaft 2. The third coil 53 may contact any part of the leaf spring 30, etc., in the inner cavity of the shaft 2, but preferably no part is fixed.

[0078] Although not illustrated, it is similar to Figure 9 and Figure 10 The first coil 51 shown is identical, and the second coil 52 has a total length L2 in its natural state and a total length L in its maximum compression state. C2 L is a better choice. C2 / L2 is less than 0.9, and preferably less than L. C1 / L1. Similarly, the third coil 53 has a total length L3 in its natural state and a total length L during maximum compression. C3 L is a better choice. C3 / L3 is less than 0.9, and preferably less than L. C1 / L1. If the total length L1 of the first coil 51 in its natural state is the same as the total length L1 under maximum compression... C1 The ratio of L C1 / L1 is equal to or less than the ratio L of the second coil 52 and the third coil 53. C2 / L2 and L C3 / L3, then the first coil 51 is deformed in the same way or more easily than the second coil 52 and the third coil 53, making it difficult to control the bending shape of the conduit 1.

[0079] The lengths of the first coil 51, the second coil 52, and the third coil 53 in the conduit 1 can be appropriately selected according to the desired curved shape. The first coil 41 and the second coil 42 can be... Figure 12 As shown, a portion is exposed between the front end 20 and the support member 60, or as... Figure 13 As shown, all three coils are arranged within the cavities of the first coil 51, the second coil 52, and the third coil 53. For example, the first coil 51 and the third coil 53 can be configured to contact the support member 60. Alternatively, the first coil 51 and the third coil 53 can be configured to be slightly spaced apart from the support member 60, exposing the first wire 41 and the second wire 42. This is also the case in the relationship between the front end 20 and the second coil 52 and the third coil 53. Similarly, the first coil 51 and the second coil 52 can be in contact or have a gap between them.

[0080] like Figure 9 As shown, the first coil 51, the second coil 52, and the third coil 53 are composed of coil wires wound in a spiral shape. The pitch interval of the first coil 51, the second coil 52, and the third coil 53 can be appropriately set. Here, the pitch interval of the coils is the distance between the center points of adjacent coil wires forming the coils. The pitch interval can be set as follows: Figure 9 The pitch interval P1 of the first coil 51 shown is measured as is. When the pitch interval is greater than the thickness of the coil wires, a gap is formed between the coil wires, allowing the coil to be compressed. At this time, the total length L of the coil in its natural state is the same as the total length L of the coil under maximum compression. C The ratio of L C / L is less than 1. Therefore, in this invention, L C / L approximates the coil wire diameter / pitch spacing. In the first coil 51, L... C1 When / L1 is 0.9 or higher, the coil wire diameter / pitch interval of the first coil 51 is 0.9 or higher.

[0081] When the conduit 1 is equipped with a second coil 52 or a third coil 53, the wire diameter and coil diameter of the second coil 52 and the third coil 53 can be appropriately selected in the conduit 1 according to the required bending shape. The materials constituting the second coil 52 and the third coil 53, as exemplified by the materials used for the first coil, can be metal or resin. Not only the pitch interval, but also the total length L of the coil in its natural state and the total length L of the coil under maximum compression can be controlled according to the wire diameter, coil diameter, and materials. C .

[0082] When the conduit 1 has a second coil 52 or a third coil 53, it is preferable that the pitch interval P1 of the first coil 51 is smaller than the pitch interval of the second coil 52 or the pitch interval of the third coil 53. By setting the pitch interval in this way, the total length L of the coil in its natural state and the total length L of the coil under maximum compression can be appropriately adjusted. C This enables L C2 / L2 and L C3 / L3 is less than L C1 / L1.

[0083] In particular, when the conduit 1 is equipped with a second coil 52, it is preferable that the pitch interval P1 of the first coil 51 is smaller than the pitch interval of the second coil 52. Furthermore, in this case, it is preferable that the coil wire diameter and coil diameter of the first coil 51 are the same as those of the second coil 52. The coil wire diameter is the diameter of the wire forming the coil, and the coil diameter is the diameter of the coil. This allows for a dimensional balance in the internal structure of the shaft 2, and also allows the rigidity of the first coil 51 and the second coil 52 to be close when bending towards the other side 32, thus making the bending shape towards the other side 32 nearly circular.

[0084] The pitch interval of the second coil 52 can be the same as or different from that of the third coil 53. The pitch intervals of both the second and third coils 53 should be such that they ensure the coils are not completely compressed during maximum bending. Because of the presence of the first coil 51, the bending diameter of the conduit 1 when bending towards one face 31 is smaller than the bending diameter when bending towards the other face 32. Furthermore, the second coil 52 is shorter than the third coil 53. Since the second coil 52 is shorter than the third coil 53, it is easier for the second coil 52 to be fully compressed. Therefore, the wider the pitch interval of the second coil 52, the better. The coil wire diameter and coil diameter of the second coil 52 can be the same as or different from those of the third coil 53, but are preferably the same. By using different pitch intervals for the second coil 52 and the third coil 53, the shapes of the bending of the conduit 1 towards one face 31 and towards the other face 32 can be made more distinct. The wire diameter and coil diameter of the first coil 51 can be the same as or different from those of the second coil 52 and the third coil 53.

[0085] Preferably, the bending stiffness of the first coil 51 is greater than that of the second coil 52, and the difference between the bending stiffness of the first coil 51 and the second coil 52 is less than 50%. This ensures that the bending shape when the distal portion 2D of the shaft bends towards one face 31 of the leaf spring 30 is a smooth bend. Methods for adjusting the stiffness include selecting the type and amount of wire constituting each coil, adjusting the inner and outer diameters of each coil, and adjusting the pitch interval of each coil.

[0086] Rigidity can pass Figure 14 The result is obtained by a three-point bending test as shown. The three-point bending test is performed according to JIS K7171. A rigidity test specimen 603 is placed on two supports 602 arranged separately on a support platform 601 with a distance D between the supports. The load F is measured when the indenter 604, which is arranged at the center of the distance D between the supports, moves a constant distance in the vertical direction. This load F is the rigidity of the rigidity test specimen 603.

[0087] like Figures 1-4 As shown, the conduit 1 with the above structure allows the distal portion 2D of the axial section to bend towards one face 31 of the leaf spring 30 via the first coil 51, resulting in a different bending shape than when the distal portion 2D bends towards the other face 32 of the leaf spring 30. Preferably, the bending diameter d1 when the distal portion 2D bends towards one face 31 of the leaf spring 30 is smaller than the bending diameter d2 when the distal portion 2D bends towards the other face 32 of the leaf spring 30. Here, the bending diameter d1 is the diameter of the circumcircle of the outer surface of the distal portion 2D bent towards one face 31 of the leaf spring 30, and is the diameter of that circle if the bend of the distal portion 2D is part of an arc. Similarly, the bending diameter d2 is the diameter of the circumcircle of the outer surface of the distal portion 2D bent towards the other face 32 of the leaf spring 30, and is the diameter of that circle if the bend of the distal portion 2D is part of an arc. Furthermore, the circumcircle of the bending shape does not necessarily need to be a perfect circle. Depending on the state of the bend, there are cases where the bend shape is a shape on the circumcircle, a straight line rather than an arc, or a combination of curves. In summary, the conduit 1 of the present invention can form a shape in which the bend on one side 31 is different from the bend on the other side 32, through the first coil 51.

[0088] like Figure 15 As shown, the preferred conduit 1 further includes a protective tube 80, which has an inner cavity and is disposed within the inner cavity of the shaft 2. A leaf spring 30, a first coil 51, a second coil 52, and a third coil 53 are disposed within the inner cavity of the protective tube 80. The protective tube 80 can be formed using the same material as the shaft 2. The protective tube 80 protects the leaf spring 30, the first coil 51, the second coil 52, and the third coil 53, and even the first wire 41 and the second wire 42. The protective tube 80 can contact any part, but is preferably fixed to the support member 60. Thus, movement of the coils within the shaft 2 can be prevented by the protective tube 80.

[0089] This application claims a benefit based on priority of Japanese Patent Application No. 2020-97338, filed on June 4, 2020. The entire contents of the description of Japanese Patent Application No. 2020-97338, filed on June 4, 2020, are incorporated herein by reference.

[0090] Explanation of reference numerals in the attached figures

[0091] 1…conduit; 2…shaft; 2D…distal part of shaft; 7…handle; 20…front end; 21…part 1; 22…part 2; 30…leaf spring; 31…one side of leaf spring; 32…the other side of leaf spring; 41…first wire; 42…second wire; 51…first coil; 52…second coil; 53…third coil; 60…support member; 70…wire operating part; 80…protective tube; 510d…distal non-fixed part; 510m…intermediate non-fixed part; 511…first fixed part; 512…second fixed part; 601…support platform; 602…fulcrum; 603…rigidity measurement sample; 604…indenter; d1…bending diameter when bending towards one side of leaf spring; d2…bending diameter when bending towards the other side of leaf spring; d L …length direction; d R …radial; D…distance between pivots; F…load; L1…total length of the first coil in its natural state; L C1 …the total length of the first coil at maximum compression; P1…the pitch interval of the first coil.

Claims

1. A catheter, characterized in that, have: A shaft having a distal end and a proximal end, and having an inner cavity extending along its length; The first line and the second line have a distal end and a proximal end, the distal end being fixed to the distal end of the shaft, and the proximal end being disposed at the proximal end of the shaft, the first line and the second line extending into the inner cavity of the shaft; A leaf spring disposed within the cavity of the shaft to separate the cavity of the shaft in the longitudinal direction into a first portion for the first line and a second portion for the second line. A support member extending along the length direction has an inner cavity for arranging the first line and the second line, the support member fixing the proximal end of the leaf spring, the support member being positioned closer to the side of the leaf spring; as well as A first coil, the first coil having an inner cavity for arranging the first wire, and disposed within the first part on a distal side relative to the distal end of the support member. in, The first coil is fixed to the proximal end of the leaf spring at at least two points. The first coil has a first fixing portion that serves as the part that fixes the first coil to the leaf spring, a second fixing portion located closer to the proximal end than the first fixing portion and also serving as the part that fixes the first coil to the leaf spring, and an intermediate non-fixed portion located between the first fixing portion and the second fixing portion and serving as the part that is not fixed to the leaf spring. The first coil has a total length L1 in its natural state and a total length L under maximum compression. C1 Their ratio L C1 / L1 is above 0.

9.

2. The catheter according to claim 1, characterized in that, The supporting component is a proximal side tube.

3. The catheter according to claim 1 or 2, characterized in that, The first coil is uncompressed.

4. The catheter according to claim 1 or 2, characterized in that, The portion of the first coil that is fixed to the leaf spring is located on the side of the first coil facing the leaf spring.

5. The catheter according to claim 1 or 2, characterized in that, The non-fixed portion of the first coil, that is, the longest non-fixed portion in the length direction, is configured such that its length in the natural state in the length direction is more than 50% of the total length L1 of the first coil in the natural state.

6. The catheter according to claim 1 or 2, characterized in that, The first coil further has a distal non-fixed portion between the distal end of the first coil and the first fixed portion, and the distal non-fixed portion does not have a fixed portion for fixing the first coil to the leaf spring.

7. The catheter according to claim 1 or 2, characterized in that, Furthermore, it has a second coil. The second coil has an inner cavity for the first coil to be arranged, and is disposed within the first part at a position more distal than the first coil.

8. The catheter according to claim 7, characterized in that, The second coil has a total length L2 in its natural state and a total length L under maximum compression. C2 Their ratio L C2 / L2 is less than 0.

9.

9. The catheter according to claim 7, characterized in that, The bending stiffness of the first coil is greater than that of the second coil, and the difference between the bending stiffness of the first coil and the bending stiffness of the second coil is less than 50%.

10. The catheter according to claim 7, characterized in that, The first coil comprises a first coil wire wound in a spiral shape. The second coil comprises a second coil wire wound in a spiral shape. The pitch interval of the first coil is smaller than that of the second coil.

11. The catheter according to claim 10, characterized in that, The wire diameter and coil diameter of the first coil are the same as those of the second coil.

12. The catheter according to claim 1 or 2, characterized in that, Furthermore, it has a third coil. The third coil has an inner cavity for the second wire to be arranged, and is located in the second part.

13. The catheter according to claim 12, characterized in that, The third coil has a total length L3 in its natural state and a total length L under maximum compression. C3 Their ratio L C3 / L3 is less than 0.

9.

14. The catheter according to claim 1 or 2, characterized in that, The device includes a second coil having an inner cavity for arranging the first coil, and is positioned on the first part at a position distal to the first coil. It includes a third coil, which has an inner cavity for arranging the second wire and is disposed in the second part. The conduit further has a protective tube, which has an inner cavity and is disposed within the inner cavity of the shaft. The leaf spring, the first coil, the second coil, and the third coil are disposed within the inner cavity of the protective tube.

15. The catheter according to claim 1 or 2, characterized in that, The first coil is fixed to the first fixing part and the second fixing part by welding, bonding or pressing.

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