Nodal ring structure and steerable catheter

Abstract

To provide a nodal ring structure that can perform stable deflection.SOLUTION: A nodal ring structure is formed by arranging multiple nodal rings so as to extend from a base end to a tip sequentially adjacently along an axial direction. Each nodal ring 5 includes: a pair of peaks 52a arranged in a substantially symmetric position to an axis center mutually; through-holes 53a, 53b which are formed along an axial direction in a side wall, and are formed separately mutually at one side of a swing center line L1 for connecting each vertex of the peak; and through-holes 53c, 53d which are formed in a substantially symmetric position with the through-holes 53a, 53b to the swing center line L1, respectively. Wire parts of 4-pieces are provided in which the tip ends are engaged to the nodal ring of the most distal end, respectively, and inserted to 4-passages configured by respective through-holes 53a-53d of the multiple nodal rings, and thereby the proximal end reaches a base end of the joint ring structure.SELECTED DRAWING: Figure 3B

Description

[Technical field]

[0001] The present invention relates to a nodal ring structure that can be suitably used in a medical treatment tool, and a steerable catheter including the same. [Background technology]

[0002] A nodal ring structure described in Patent Document 1 is known as a technique for deflecting the tip of an endoscope inserted into the body. This nodal ring structure is configured by arranging a plurality of metal nodal rings along the axial direction, each having a pair of crests that serve as a swing fulcrum formed at 180° opposite positions. Each nodal ring has four through holes formed at an angular pitch of approximately 90°, and of these four through holes, a pair of through holes that are 180° opposite each other are formed in a pair of crests as coupling wire insertion holes through which a coupling wire is inserted, and the other pair of through holes serve as deflection wire insertion holes through which a deflection wire (oscillating wire) is inserted.

[0003] The node rings are linked by appropriately laser welding and connecting (fixing) metal linking wires that are respectively inserted into a pair of linking wire insertion holes. By pulling one of the deflection wires that are respectively inserted into a pair of deflection wire insertion holes, each node ring rotates to one side with the peak portion as a fulcrum, and by pulling the other one, each node ring rotates to the other side with the peak portion as a fulcrum, thereby allowing deflection (bending).

[0004] However, in conventional nodal ring structures, the pair of connecting wires is provided only to connect the nodal rings, and the tensile force when deflecting the nodal ring structure is transmitted to the tip of the nodal ring structure via one of the two deflection wires, i.e., a single deflection wire, which causes shaking during deflection and can make it difficult to perform stable deflection. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-253387 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a node ring structure capable of performing stable deflection, and a movable catheter including the same. [Means for solving the problem]

[0007] In order to achieve the above object, a joint ring structure according to a first aspect of the present invention comprises: A joint ring structure including a plurality of joint rings each having a substantially cylindrical portion, the joint rings being arranged adjacent to each other in an axial direction and extending from a base end to a tip end, Each of the plurality of joint rings is a pair of ridges formed on at least one of both end surfaces of the cylindrical portion and disposed at positions substantially symmetrical to each other with respect to the axis; a first through hole and a second through hole formed in a side wall of the cylindrical portion along an axial direction and spaced apart from each other on one side of a swing center line connecting the apexes of the mountain portions, and a third through hole and a fourth through hole formed on the other side of the swing center line and positioned approximately symmetrically to the first through hole and the second through hole with respect to the swing center line, a first wire portion that is inserted through a wire passage formed by each of the first through holes, has a distal end portion that engages with the most distal joint ring, and has a proximal end portion that reaches a proximal end of the joint ring structure; a second wire portion that is inserted through a wire passage formed by each of the second through holes, has a tip portion that engages with the most distal node ring, and has a base portion that reaches a base end of the node ring structure; a third wire portion that is inserted through a wire passage formed by each of the third through holes, has a tip portion that engages with the most distal node ring, and has a base portion that reaches the base end of the node ring structure; and The joint ring structure is provided with a fourth wire portion that is inserted into the wire passage formed by each fourth through hole, has a tip portion that engages with the most distal joint ring, and has a base end portion that reaches the base end of the joint ring structure.

[0008] In the nodal ring structure according to the first aspect of the present invention, the nodal ring structure can be deflected (bent) to one side by simultaneously pulling the first wire section and the second wire section toward the base end, or the nodal ring structure can be deflected (bent) to the other side by simultaneously pulling the third wire section and the fourth wire section toward the base end. Therefore, the tensile force when deflecting the nodal ring structure can be transmitted to the tip of the nodal ring structure via two wire sections spaced apart from each other, and compared to the conventional technology that uses one wire to perform this, it is possible to suppress shaking during deflection and perform stable deflection. Moreover, since the nodal rings can be connected without providing a wire (connecting wire) just to connect the nodal rings as in the conventional technology, the configuration does not become complicated.

[0009] In the nodal ring structure according to the first aspect of the present invention, the first through hole, the second through hole, the third through hole, and the fourth through hole can be formed so that the oscillation center line and a line connecting the centers of the first through hole and the fourth through hole intersect at approximately 45°, and the oscillation center line and a line connecting the centers of the second through hole and the third through hole intersect at approximately 45°. By configuring in this manner, the wire portions are arranged in a well-balanced manner, so that stable deflection can be achieved while ensuring connection of the nodal rings.

[0010] In the nodal ring structure according to the first aspect of the present invention, the first wire portion, the second wire portion, the third wire portion, and the fourth wire portion may each be formed from a wire independent of one another, with the tip end of each wire being connected to the most distal nodal ring. The nodal ring structure can be deflected (bent) to one side by simultaneously pulling the base end of the wire constituting the first wire portion and the base end of the wire constituting the second wire portion toward the base end, or the nodal ring structure can be deflected (bent) to the other side by simultaneously pulling the base end of the wire constituting the third wire portion and the base end of the wire constituting the fourth wire portion toward the base end.

[0011] A steerable catheter according to a second aspect of the present invention is a steerable catheter having the nodal ring structure according to the first aspect of the present invention, comprising a flexible tube having a main lumen and four wire lumens formed in a tube wall corresponding to each of the wire passages of the nodal ring structure, the base end of the nodal ring structure and the distal end of the tube are disposed adjacent to each other, and the ends of the first wire portion, the second wire portion, the third wire portion and the fourth wire portion that reach the base end of the nodal ring structure are inserted into the corresponding wire lumens and reach the proximal end of the tube. This provides a steerable catheter that can achieve stable deflection. [Brief description of the drawings]

[0012] [Figure 1A] FIG. 1A is a front view showing the external configuration of a movable catheter equipped with a nodal ring structure according to an embodiment of the present invention. [Figure 1B] FIG. 1B is a cross-sectional view taken along line Ib-Ib in FIG. 1A. [Figure 2A] FIG. 2A is a front view of the distal end of the steerable catheter of FIG. 1A, showing the deflection section in an undeflected (bent) state. [Figure 2B] FIG. 2B is a side view of the deflection portion of the steerable catheter of FIG. 2A, seen from the distal end. [Figure 2C]FIG. 2C is a plan view of the distal end of the steerable catheter of FIG. 2A. [Figure 2D] FIG. 2D is a front view of the distal end of the steerable catheter of FIG. 2A, showing the deflection section in a deflected (curved) state. [Figure 3A] FIG. 3A is a front view of a node ring that constitutes the deflection portion of the steerable catheter of FIG. 2A. [Figure 3B] FIG. 3B is a side view of the node ring of FIG. 3A as viewed from the base end side. [Figure 3C] FIG. 3C is a plan view of the node ring of FIG. 3A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, as an embodiment of the present invention, a movable catheter as a medical treatment tool having a deflection section (movable section) made of a nodal ring structure will be specifically described with reference to the drawings. The movable catheter of this embodiment is, for example, a movable endoscopic catheter that is inserted into the bile duct via the duodenal papilla through the treatment tool guide tube of an endoscope and is used for injecting an X-ray contrast medium for examination inside the bile duct.

[0014] However, the present invention is not limited to endoscopic catheters inserted into the body via an endoscope, and can be applied, for example, to catheter sheaths that are inserted prior to an electrode catheter for detecting an electrocardiogram or an ablation catheter for cauterizing an affected area when performing catheter ablation, and that guide these electrode catheters, ablation catheters, etc. The present invention can also be applied to catheters such as electrode catheters and ablation catheters that are inserted into the body via a guiding member such as a catheter sheath, or catheters that are directly inserted into a lumen in the body without passing through a guiding member such as an endoscope or a catheter sheath.

[0015] Catheter ablation is a treatment for treating arrhythmias occurring in the heart. An ablation catheter having a high-frequency electrode at its tip is inserted through a blood vessel into the myocardial tissue that emits the abnormal electrical signals that cause the arrhythmia in the heart, and the myocardial tissue or its vicinity is cauterized at about 60 to 70°C to cause coagulation necrosis, thereby blocking the transmission pathway of the abnormal electrical signals that cause the arrhythmia.

[0016] First, referring to Figures 1A and 1B, a steerable endoscope catheter (steerable catheter) 1 is generally configured to include a sheath portion 2, an operation portion 3, a grip portion 4, and a pair of wires W1, W2.

[0017] The sheath portion 2 is made of a long member having a distal end that is inserted into the body and a proximal end that is placed outside the body, and is composed of a sheath main body portion (tube) 20 made of a flexible, long tube having a main lumen 22, and a deflection portion (nodal ring structure) 21 as a movable portion provided continuously (adjacently) to the distal end of the sheath main body portion 20.

[0018] A multi-layer tube including, for example, a braid layer made of meshed stainless steel or the like and a plurality of resin layers is used as the sheath body 20. The resin material used for the sheath body 20 is not particularly limited, but it is preferable to use a thermoplastic resin or a thermoplastic elastomer, and examples of the resin material that can be used include polyamide-based elastomers such as polyether block amide copolymers, polyamide, polyimide, polyamideimide, polyethylene terephthalate, polyethylene, polypropylene, polyurethane, ethylene-vinyl acetate copolymers, polyvinyl chloride, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymers, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers.

[0019] Four wire lumens (sub-lumens) 23a to 23d are formed in the tube wall of the sheath body 20 so as to surround the outside of the main lumen 22 and are generally parallel to the main lumen 22. The wire lumens 23a to 23d are formed from the proximal end to the distal end (proximal end of the deflection section 21) of the sheath body 20. The wire lumens 23a to 23d are formed at an angular pitch (angular interval) of approximately 90° around the axis of the sheath body 20, outside the main lumen 22. The distal ends of the wire lumens 23a to 23d open into the distal end face of the sheath body 20.

[0020] The wire lumen 23a is a lumen through which approximately one half (first wire portion) W1a of the wire W1 on one end side is slidably inserted, the wire lumen 23b is a lumen through which approximately one half (second wire portion) W1b of the wire W1 on the other end side is slidably inserted, the wire lumen 23c is a lumen through which approximately one half (third wire portion) W2a of the wire W2 on one end side is slidably inserted, and the wire lumen 23d is a lumen through which approximately one half (fourth wire portion) W2b of the wire W2 on the other end side is slidably inserted.

[0021] The outer diameter of the sheath main body 20 can be set within a range of 1 to 10 mm, and the inner diameter can be set within a range of 0.5 to 9.5 mm. The overall length of the sheath portion 2 can be set within a range of 100 to 3000 mm. The diameters of the wire lumens 23a to 23d can be set within a range of φ0.05 to 5 mm.

[0022] 2A to 2D, the deflection section 21 is composed of a nodal ring structure in which a plurality of nodal rings 5, each having a substantially cylindrical portion 51, are arranged adjacent to one another in substantially the same orientation along the axial direction so as to extend from the base end to the tip end, and are arranged adjacent to one another so that the base end side is continuous with the distal end of the sheath main body 20. The number of nodal rings 51 constituting the deflection section 21 is not particularly limited, but in the embodiment shown in FIG. 2A, as an example, there are 12 nodal rings 51.

[0023] As shown in Figs. 3A to 3C, the joint ring 51 has a pair of peaks 52, 52 formed to protrude from one of both end faces of the cylindrical portion 51 (in this embodiment, the face on the base end side) and arranged at positions approximately symmetrical to each other with respect to the axis (positions facing each other by 180°). The joint ring 5 can swing (rotate) to one side and the other side about a line (swing center line L1) connecting the vertices 52a, 52a with respect to the face on the tip side of the joint ring 5 with which the vertices 52a, 52a of the peaks 52, 52 a abut or the distal end face of the sheath main body 20. The pair of peaks may be provided on the face on the tip side instead of the base end side of the cylindrical portion 51, or may be provided on the face on the tip side in addition to the face on the base end side.

[0024] Four wire through holes (first to fourth through holes) 53a to 53d are formed in the axial direction in the side wall of the cylindrical portion 51 of the node ring 5. The wire through holes 53a and 53b are formed spaced apart from each other on one side (upper side in FIG. 3B) of the swing center line L1 connecting the vertices 52a, 52a of the mountain portions 52, 52. The wire through holes 53c and 53d are formed on the other side (lower side in FIG. 3B) of the swing center line L1, at positions approximately symmetrical to the wire through holes 53a and 53b with respect to the swing center line L1.

[0025] In this embodiment, the wire through holes 53a to 53d are arranged at an angle pitch of approximately 90° with respect to each other, and are formed so that the swing center line L1 and a line L2 connecting the centers of the wire through holes 53a and 53d intersect at approximately 45°, and the swing center line L1 and a line L3 connecting the centers of the wire through holes 53b and 53c intersect at approximately 45°. The wire through hole 53a corresponds to the wire lumen 23a of the sheath body 20, the wire through hole 53b corresponds to the wire lumen 23b of the sheath body 20, the wire through hole 53c corresponds to the wire lumen 23c of the sheath body 20, and the wire through hole 53d corresponds to the wire lumen 23d of the sheath body 20.

[0026] In this embodiment, four thick-walled portions 55a-55d are provided that extend along the axial direction of the node ring 5 and protrude inward from the inner wall surface of the node ring 5, and the wire through holes 53a-53d are formed in the corresponding thick-walled portions 55a-55d. This is to reduce (thin) the thickness (side wall thickness) of the cylindrical portion 51 from the viewpoint of reducing the weight of the node ring 5, but if the side wall of the cylindrical portion 51 has a sufficient thickness, the wire through holes 53a-53d may be formed in the side wall of the cylindrical portion 51 without providing such thick-walled portions 55a-55d.

[0027] The material of the joint ring 5 is not particularly limited, but is preferably a resin, and for example, a polyamide-based elastomer such as a polyether block amide copolymer, polyamide, polyimide, polyamideimide, polyethylene terephthalate, polyethylene, polypropylene, polyurethane, ethylene-vinyl acetate copolymer, polyvinyl chloride, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, etc. can be used. Although not particularly limited, in this embodiment, the outer diameter of the cylindrical portion 51 of the joint ring 5 is approximately the same as the outer diameter of the sheath main body 20, and the inner diameter of the thick-walled portions 55a to 55d of the cylindrical portion 51 of the joint ring 5 is approximately the same as the inner diameter of the sheath main body 20. The inner diameter of the portion other than the thick-walled portions 55a to 55d of the cylindrical portion 51 of the joint ring 5 can be set within a range of 0.5 to 9.5 mm. The length of the joint ring 5 in the axial direction (the dimension from the tip surface to the apex 52a of the mountain portion 52 on the base end side) can be set within a range of 1 to 5 mm. The inclination angle θ of the peak portion 52 (the angle with respect to a plane perpendicular to the axis) can be set in the range of 1 to 45°, and is more preferably set in the range of 5 to 20°. In this embodiment, the diameters of the wire through holes 53a to 53d are approximately the same as the diameters of the wire lumens 23a to 23d of the sheath body 20.

[0028] 1A, a distal end of the deflection section 21 (the tip of the most distal nodal ring 5) is provided with a substantially cylindrical tip protection member 24 made of resin and having a hemispherical (or tapered truncated cone) distal end. The tip protection member 24 has an inner cavity with substantially the same diameter as the main lumen 22, and is integrally joined (fixed) to the distal end of the deflection section 21 by heat fusion or the like. However, the tip protection member 24 may be omitted.

[0029] 2A to 2D, a single wire W1 is inserted through the wire passage 54a and the corresponding wire lumen 23a formed by the wire through holes 53a of the multiple nodal rings 5 ​​(cylindrical portion 51) constituting the deflection portion 21, as well as the wire passage 54b and the corresponding wire lumen 23b formed by the wire through holes 53b of the multiple nodal rings 5 ​​(cylindrical portion 51) constituting the deflection portion 21. Also, a single wire W2 is inserted through the wire passage 54c and the corresponding wire lumen 23c formed by the wire through holes 53c of the multiple nodal rings 5 ​​(cylindrical portion 51) constituting the deflection portion 21, as well as the wire passage 54d and the corresponding wire lumen 23d formed by the wire through holes 53d of the multiple nodal rings 5 ​​(cylindrical portion 51).

[0030] These wires W1 and W2 have the functions of connecting each of the nodal rings 5 ​​that constitute the deflection section 21 to each other, and connecting the base end of the deflection section 21 (the base-most nodal ring 5) to the distal end of the sheath main body section 20, and of rotating each of the nodal rings 5 ​​to one side or the other about each of the swing center lines L1 by pulling both ends of the wire W1 toward the base end side (proximal end side) or both ends of the wire W2 toward the base end side (proximal end side), thereby deflecting (curving) each of the nodal rings 5 ​​as a whole to one side or the other side.

[0031] Approximately half of the wire W1 (first wire portion) W1a on one end side is inserted into the wire passage 54a and the wire lumen 23a, and the middle portion W1c is folded back at the tip surface (the distal end surface to which the tip protection member 24 is joined) of the most distal node ring 5 of the deflection section 21, and approximately half of the other end side (second wire portion) W1b is inserted into the wire passage 54b and the wire lumen 23b, and both ends (one end and the other end) are positioned in the operating section 3 on the proximal end side of the sheath section 2 (sheath main body section 20). Similarly, approximately half (third wire portion) W2a of one end of the wire W2 is inserted into the wire passage 54c and the wire lumen 23c, and the middle portion W2c is folded back at the tip surface (the distal end surface to which the tip protection member 24 is joined) of the most distal node ring 5 of the deflection portion 21 of the sheath 2, and approximately half (fourth wire portion) W2b of the other end of the wire W2 is inserted into the wire passage 54d and the wire lumen 23d, and both ends (one end and the other end) are positioned in the operating portion 3 on the proximal end side of the sheath portion 2 (sheath main body portion 20).

[0032] In this embodiment, the wires W1 and W2 are made of a metal (such as stainless steel) having flexibility enough to bend in accordance with the curvature of the sheath portion 2 (the sheath body portion 20 and the deflection portion 21). However, the wires W1 and W2 may be made of a resin. The diameter of the wire constituting the wires W1 and W2 can be set within a range of about φ0.05 to 1.00 mm.

[0033] From a state in which the deflection section 21 is a linear shape (see FIG. 2A) in which the axes of the respective nodal rings 5 ​​are arranged in a substantially straight line, the deflection section 21 can be changed to a curved shape (see FIG. 2D) in which the axes of the respective nodal rings 5 ​​are curved so as to sequentially intersect with each other, by simultaneously pulling both ends of the wire W1 toward the proximal end at the proximal end of the sheath section 2. Conversely, by simultaneously pulling both ends of the wire W2 toward the proximal end at the proximal end of the sheath section 2, the deflection section 21 can be returned to the linear shape shown in FIG. 2A, and by further pulling, the deflection section 21 can be changed to a curved shape curved in the opposite direction to that in FIG. 2D (see arrow A3 in FIG. 1A).

[0034] In FIG. 1A, an insertion hole (not shown) through which the proximal end portion of the sheath main body 20 is inserted is formed in the operating section 3 and grip section 4 attached to the proximal end side of the sheath section 2, and a port 41 is provided on the proximal end side of the grip section 4.

[0035] The port 41 has an inner cavity, and the sheath body 20 in the grip section 4 is attached to the proximal end side of the port 41 so that the inner cavity of the port 41 communicates with the main lumen 22 of the sheath body 20. The port 41 also has an insertion port equipped with a hemostatic valve. By connecting a syringe to this insertion port, a contrast agent or other medicinal liquid can be injected into the body (in the bile duct) via the main lumen 22, or liquid within the body (in the bile duct) can be aspirated.

[0036] Both ends of the wire W1 and both ends of the wire W2 are drawn out from side holes provided in the sheath body 20 inside the operation section 3 provided on the proximal end side of the sheath section 2, and are respectively connected to the operation section 3 (rotation operation member 31). The rotation operation member 31 is provided rotatably with respect to the grip section 4, and the surgeon can selectively deflect the deflection section 21 by gripping the rotation operation member 31 with his / her hand and rotating it in one direction or the opposite direction, thereby pulling one of the wires W1 (wire sections W1a, W1b) and W2 (wire sections W2a, W2b) and loosening the other.

[0037] In the neutral state shown in FIG. 1A, initial tension is applied equally to both wire W1 (wire portions W1a, W1b) and wire W2 (wire portions W2a, W2b), and the deflection portion 21 at the tip of the sheath portion 2 is in a linearly extended state (straight body) (see also FIGS. 2A and 2C).

[0038] From the neutral state, when the rotary operating member 31 is operated to rotate it in the direction of arrow A1 in FIG. 1, as a result of this rotation, the wire W1 (wire portions W1a, W1b) is loosened and the wire W2 (wire portions W2a, W2b) is pulled, causing the deflection portion 21 at the tip to be deflected as shown by the arrow A3 in FIG. 1A.

[0039] Conversely, when the rotating operating member 31 is operated to rotate it in the direction of arrow A2 in Figure 1, the wire W1 is pulled and the wire W2 is released, causing the deflection portion 21 at the tip to be deflected as shown by arrow A4 in Figure 1A (see also Figure 2D).

[0040] In the above-described embodiment, both ends of the wire W1 (the proximal end of the wire portion W1a and the proximal end of the wire portion W1b) are pulled toward the proximal end simultaneously to deflect (bend) the nodal ring structure constituting the deflection portion 21 to one side. Also, both ends of the wire W2 (the proximal end of the wire portion W2a and the proximal end of the wire portion W2b) are pulled toward the proximal end simultaneously to deflect (bend) the nodal ring structure constituting the deflection portion 21 to the other side.

[0041] Therefore, the tensile force when deflecting the deflection unit 21 is transmitted to the tip of the deflection unit 21 (the most distal nodal ring 5) via substantially two wires (wire portion W1a and wire portion W1b or wire portion W2a and wire portion W2b) that are spaced apart from each other. Therefore, when deflecting, the force can be applied to a relatively wide range in the circumferential direction of the sheath portion 2, and compared to the conventional technology in which the tensile force is applied by a single wire, it is possible to suppress shaking during deflection and perform stable deflection. In addition, since the tensile force can be distributed, the force applied to the wire (wire portion) can be reduced, and wire breakage due to the deflection operation can be reduced. Moreover, since the nodal rings can be connected without providing a wire just for connecting the nodal rings as in the conventional technology, the configuration does not become complicated.

[0042] In the above-described embodiment, the wire through holes 53a to 53d are formed such that the oscillation center line L1 and the line L2 connecting the centers of the wire through holes 53a and 53d intersect at approximately 45°, and the oscillation center line L1 and the line L3 connecting the centers of the wire through holes 53b and 53c intersect at approximately 45°. Therefore, the wire portions W1a, W1b, W2a, and W2b are evenly and balancedly arranged, and stable deflection can be achieved while sufficiently securing the connection of each node ring 5.

[0043] Furthermore, in the above-described embodiment, the wire portion W1a and the wire portion W1b are each formed of a single wire that is integrally continuous with each other at their respective distal ends (middle portions W1c), and the wire portion W2a and the wire portion W2b are each formed of a single wire that is continuous with each other at their respective distal ends (middle portions W2c). In this way, the middle portions W1c and W2c of the wires W1 and W2 can be folded back and engaged at the distal end surface (the distal end surface of the most distal nodal ring 5) of the deflection portion 21, so that the work of connecting (fixing) the wires W1 and W2 to the distal end portion of the deflection portion 21 can be omitted, and the number of work steps in the manufacturing process can be reduced.

[0044] However, the intermediate portions W1c, W2c of the wires W1, W2 may be connected (fixed) to the most distal node ring 5. Also, instead of the wires W1, W2, a single wire corresponding to the wire portion W1a, a single wire corresponding to the wire portion W1b, a single wire corresponding to the wire portion W2a, and a single wire corresponding to the wire portion W2b may be provided, that is, four mutually independent wires may be provided, one wire each inserted into the wire passages 54a-54d and the corresponding wire lumens 23a-23d, and the distal end of each wire may be connected (fixed) to the distal end of the deflection portion 21 (the most distal node ring 5) to engage them.

[0045] The above-described embodiments are described for the purpose of facilitating understanding of the present invention, and are not described for the purpose of limiting the present invention. Therefore, each element disclosed in the above-described embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0046] For example, an outer tube (covering tube) having flexibility to the extent that it does not interfere with the deflection (bending) of the deflection unit 21 may be arranged (fitted) on the outside of each nodal ring 5 constituting the deflection unit 21. In this way, it is possible to prevent internal body tissue from being pinched between the nodal rings 5 ​​when the deflection unit 21 is deflected (bended). In addition, for example, in the case of a movable catheter (catheter sheath) in which a long member such as another catheter is inserted into the main lumen 22, an inner tube having flexibility to the extent that it does not interfere with the deflection (bending) of the deflection unit 21 may be arranged (fitted) on the inside of each nodal ring 5 constituting the deflection unit 21. In this way, it is possible to prevent the distal end of the long member from interfering with the portion between the nodal rings 5 ​​constituting the deflection unit 21 from the inside when the long member is inserted, thereby preventing smooth insertion. [Explanation of symbols]

[0047] 1...Movable endoscope catheter (movable catheter) 2…Sheath part 20…Sheath body (tube) 21...Deflection part (nodal ring structure) 22…Main lumen 23a~23d…Wire lumen 24…Tip protection member 3...Operation unit 31...Rotational operation member 4…Grip section 41…Port 5…Node ring 51...Cylindrical part 52…Yamabe 52a...top 53a...Wire through hole (first through hole) 53b...Wire through hole (second through hole) 53c...Wire through hole (third through hole) 53d…Wire through hole (fourth through hole) 54a~54d…Wire passage 55a~55d…thick part L1: Swing center line W1…Wire (first wire) W1a…Wire part (first wire part) W1b…Wire section (second wire section) W2…Wire (second wire) W2a…Wire section (third wire section) W2b…Wire section (4th wire section)

Claims

1. A joint ring structure including a plurality of joint rings each having a substantially cylindrical portion, the joint rings being arranged adjacent to each other in an axial direction and extending from a base end to a tip end, Each of the plurality of joint rings is a pair of ridges formed on at least one of both end surfaces of the cylindrical portion and disposed at positions substantially symmetrical to each other with respect to the axis; a first through hole and a second through hole formed in a side wall of the cylindrical portion along an axial direction and spaced apart from each other on one side of a swing center line connecting the apexes of the mountain portions, and a third through hole and a fourth through hole formed on the other side of the swing center line and positioned approximately symmetrically to the first through hole and the second through hole with respect to the swing center line, a single first wire, one end of which is inserted through a wire passage formed by each of the first through holes and reaches a base end of the joint ring structure, a middle portion of which is folded back at a tip end surface of the most distal joint ring, and the other end of which is inserted through a wire passage formed by each of the second through holes and reaches the base end of the joint ring structure; a single second wire is provided, the one end of which is inserted through a wire passage formed by each of the third through holes and reaches the base end of the joint ring structure, the intermediate portion of which is folded back at the tip end surface of the most distal joint ring, and the other end of which is inserted through a wire passage formed by each of the fourth through holes and reaches the base end of the joint ring structure; a joint ring structure including a rotary operating member to which one end and the other end of the first wire and one end and the other end of the second wire are respectively connected, and which is capable of pulling the one end and the other end of the first wire simultaneously and loosening the second wire by manually rotating the rotary operating member in one direction, and pulling the one end and the other end of the second wire simultaneously and loosening the first wire by manually rotating the rotary operating member in the opposite direction.

2. 2. The articulation ring structure according to claim 1, wherein the first through hole, the second through hole, the third through hole, and the fourth through hole are formed such that the oscillation center line and a line connecting the centers of the first through hole and the fourth through hole intersect at approximately 45°, and the oscillation center line and a line connecting the centers of the second through hole and the third through hole intersect at approximately 45°.

3. A movable catheter having the joint ring structure according to claim 1 or 2, a flexible tube having a main lumen and four wire lumens formed in a tube wall corresponding to each of the wire passages of the joint ring structure; a proximal end of the articulation structure and a distal end of the tube are disposed adjacent to each other; a movable catheter in which one end and the other end of the first wire that reach the base end of the nodal ring structure, and one end and the other end of the second wire that reach the base end of the nodal ring structure, are inserted into the corresponding wire lumens and reach the proximal end of the tube.

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