JP4969289B2 - Tip deflectable catheter - Google Patents

Description

  The present invention relates to a catheter capable of tip deflection operation. More specifically, the distal end of a catheter inserted into a body cavity is operated by operating an operation portion on the proximal end side disposed outside the body. The present invention relates to a catheter capable of tip deflection operation that can easily change the direction of the distal end.

  For example, in the case of an electrode catheter inserted into the heart through arterial blood vessels, the orientation of the distal end (tip) of the catheter inserted into the heart is set to the proximal end (rear end or proximal side) of the catheter placed outside the body. ) Needs to be operated to change (deflection).

  Conventionally, the following mechanism is known as a mechanism for deflecting the distal end of the catheter by operating on the proximal side.

  For example, as shown also in the following Patent Document 1, there is known one in which a leaf spring having a spring force and a tension wire are mounted inside a distal end portion of a flexible catheter. In this mechanism, by operating the tension wire on the hand side, the leaf spring connected to the tip of the tension wire can be bent in a direction substantially perpendicular to the plane of the leaf spring. As a result, the distal end of the catheter can be turned in a predetermined direction.

  However, in such a mechanism, the lumen inside the catheter is occupied by a bending operation mechanism such as a leaf spring, the cross-sectional area of the lumen is narrowed, and it is difficult to arrange other functional members inside the lumen. Have. Examples of other functional members include wiring for a plurality of electrodes, cooling means, and an optical fiber.

Since the catheter is used by being pushed through a narrow blood vessel, it is necessary to make the outer diameter of the catheter as small as possible. However, with the conventional leaf spring mechanism, it is difficult to reduce the outer diameter of the catheter. It was. It is conceivable to reduce the outer diameter of the catheter by reducing the width of the leaf spring. However, if the width of the spring leaf is reduced in this way, the spring force is reduced and restored after the distal end of the catheter is bent. The power to do is weakened.
Japanese Patent No. 3232308

  The present invention has been made in view of such a situation, and the object thereof is to enable effective use of the internal lumen of the catheter, to reduce the outer diameter of the catheter, and also to a restoring function after bending. It is an object of the present invention to provide an excellent tip deflection operable catheter.

In order to achieve the above object, a catheter capable of tip deflection operation according to the present invention is provided.
A catheter tube having at least one lumen extending along an axial direction;
A leaf spring housed in the lumen and extending in the longitudinal direction from the proximal end to the distal end .

  In the distal deflection operable catheter according to the present invention, a leaf spring having a ridge formed on one or both sides constitutes a deflection mechanism, and the distal end of the leaf spring is substantially perpendicular to the flat plate plane of the leaf spring. Is bendable. In the catheter capable of deflecting the distal end according to the present invention, even if the width of the leaf spring is reduced, the spring force of the leaf spring is reinforced by the ridges, and the restoring function after bending is excellent.

  Therefore, in the present invention, the width of the leaf spring can be reduced, and the cross-sectional space of the lumen in which the leaf spring is accommodated can be used effectively. The inside of the lumen is inserted through the operation wire. It can be used as a hole or a wiring path. That is, the internal lumen of the catheter is not blocked by the deflection mechanism, and the lumen can be used effectively.

  Further, in the distal deflection operable catheter according to the present invention, the leaf spring exerts a reinforcing effect on the catheter tube, and improves the push-in characteristic of the catheter. Furthermore, in the catheter capable of deflecting the distal end according to the present invention, since the deflection mechanism is constituted by a convex leaf spring, the number of parts is reduced and its manufacture is easy.

  Preferably, the distal end of the manipulation wire is connected to the distal end side of the leaf spring. The distal ends of the operation wires may be connected to both the front and back surfaces of the flat plate portion at the distal end of the leaf spring, respectively, or on one side surface of the front and back surfaces of the flat plate portion at the distal end of the leaf spring. The distal end of the operating wire may be connected.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a schematic side view of an electrode catheter according to an embodiment of the present invention.
2 is a cross-sectional view of an essential part of the distal end side of the catheter shown in FIG.
FIG. 3 is a cross-sectional view of an essential part taken along line III-III in FIG.
4 is an enlarged sectional view of the leaf spring shown in FIG.
5 (A) to 5 (D) are cross-sectional views of leaf springs used for electrode catheters according to other embodiments of the present invention,
FIG. 6 is a perspective view of a main part of a catheter tube used for an electrode catheter according to another embodiment of the present invention,
7 is a cross-sectional view taken along the line VII-VII shown in FIG.

  As shown in FIG. 1, an electrode catheter 2 as a catheter capable of tip deflection operation according to an embodiment of the present invention is used, for example, for diagnosis or treatment of arrhythmia in the heart, and a distal end portion of a catheter tube 4. A tip electrode 10 and a plurality of ring electrodes 12 are attached to 4a. A connector 6 is attached to the proximal end 4 b of the catheter tube 4. From the connector 6, lead wires for conducting wires electrically connected to the electrodes 10 and 12 are drawn out. The connector 6 is equipped with a knob 7 for performing a deflection movement operation of the distal end portion of the catheter tube 4.

  The tip electrode 10 and the ring electrode 12 shown in FIG. 1 are made of a metal having good thermal conductivity, such as aluminum, copper, stainless steel, gold, or platinum. In addition, in order to give favorable contrast properties for X-rays, the tip electrode 10 and the ring electrode 12 are preferably made of platinum or the like. The outer diameters of the distal tip electrode 10 and the ring-shaped electrode 12 are not particularly limited, but are preferably about the same as the outer diameter of the catheter tube 4 and are usually about 0.5 to 3 mm. These electrodes 10 and 12 are used for measuring the potential of a living tissue such as the heart or used for ablation of living tissue.

  The catheter tube 4 is made of a synthetic resin such as polyolefin, polyamide, polyether polyamide, or polyurethane. The outer diameter of the catheter tube 4 is generally about 0.5 to 3 mm, and the inner diameter is about 0.2 to 2.5 mm. As shown in FIG. 2, the catheter tube 4 is formed with a single lumen 14 along the axial direction.

  As shown in FIGS. 2 and 3, a leaf spring 20 is attached to the lumen 14 of the catheter tube 4. As shown in FIGS. 4 and 5, the leaf spring 20 has a flat plate portion 22 and a ridge 24 having a semicircular cross section formed integrally with the front and back surfaces of the flat plate portion 22. The ridges 24 are continuously formed along the longitudinal direction of the flat plate portion 22. However, in the present invention, the ridges 24 are not necessarily continuous and may be formed intermittently.

  The width w1 of the flat plate portion 22 in the leaf spring 20 is preferably about 40 to 60% with respect to the inner diameter Φ1 of the catheter tube 4, and specifically, 0.6 to 1.6 mm. The thickness t1 of the flat plate portion 22 is not particularly limited, but is preferably 100 to 200 μm.

  The protrusion height h1 of the ridge 24 is preferably 10 to 50% of the thickness t1 of the flat plate portion 22. As shown in FIG. 4, the width w <b> 2 of the ridge 24 is preferably 10 to 50% of the width w <b> 1 of the flat plate portion 22. The ridges 24 formed on both sides of the front and back surfaces of the flat plate portion 22 have the same shape and the same dimensions in the present embodiment, but may be different from each other in the present invention.

  The material of the flat plate portion 22 in the plate spring 20 is not particularly limited as long as it is a material having spring characteristics. Specifically, the plate portion 22 is made of SUS, Ni—Ti, Fe, or the like.

  The ridges 24 are formed integrally with the flat plate portion 22 and are made of the same material as the flat plate portion 22. However, in the present invention, the ridges 24 are not necessarily made of the same material, and are necessarily formed integrally. Nor. For example, the ridges 24 made of the same or different materials may be joined to the flat plate portion 22 by laser welding or the like, and the leaf spring 20 in which the ridges 24 and the flat plate portion 22 are integrated is rolled. For example, they may be integrally formed at the same time.

  As shown in FIG. 2, the distal end 20 a of the leaf spring 20 extends to the vicinity of the distal tip electrode 10 that is connected and fixed to the distal end of the catheter tube 4, and is in contact with the electrode 10. However, it is preferable that the connection is fixed as long as insulation is ensured. The proximal end 20 b of the leaf spring 20 is connected and fixed to the distal end of the proximal end side coil spring 26. The proximal end side plate coil spring 26 has a reinforcing function on the proximal end side of the catheter tube 4.

  The proximal end 20b of the leaf spring 20 shown in FIG. 2 is preferably located at a distance L3 from the distal end of the catheter 2 shown in FIG. The distance L3 is preferably about 5 to 15% of the total length L0 of the catheter 2 excluding the connector 6. The total length L0 of the catheter 2 is not particularly limited, but is preferably 300 to 1000 mm.

  As will be described later, by operating the knob 7, the distal end of the catheter tube 4 bends in the direction of the arrow A1 and the direction of the arrow A2 from the position of the distance L3 from the distal end of the catheter 2. Therefore, the proximal end side coil spring 26 may be made of a material or a structure that has higher bending elasticity than the leaf spring 20 disposed at the distal end thereof and is relatively difficult to bend.

  As shown in FIG. 2, near the distal end 20a of the leaf spring 20, the distal ends of the pair of operation wires 30 are laser-welded, spot-welded, welded, brazed, caulked, glued by an adhesive, etc. It is joined by the means. The distal ends of the pair of operation wires 30 are respectively joined to the front and back surfaces of the flat plate portion 22 of the plate spring 20.

  The outer diameter of the operation wire 30 is not particularly limited, but is preferably 0.01 to 0.2 mm, and more preferably 0.03 to 0.08 mm. The operation wire 30 is made of, for example, a Ni—Ti superelastic alloy. The operation wire 30 is inserted into the operation tube so as to be movable in the axial direction. The operation tube is made of, for example, a low-friction coefficient fluororesin (eg, PTFE) tube, and its inner diameter is slightly larger than the outer diameter of the operation wire 30, and its thickness is not particularly limited. 0.03 to 0.08 mm.

  As shown in FIG. 2, the pair of operation wires 30 passes through the lumen 14 of the catheter tube 4 and further extends to the operation connector 6 shown in FIG.

  The proximal end portions of the pair of operation wires 30 are driven to rotate by, for example, the rotary knob 7 of the operation connector 6 shown in FIG. 1, and one operation wire 30 is pulled, and the other operation wire 30 is pulled. It is unwound in the same amount as the amount.

  For example, as a result of operating the rotary knob 7 shown in FIG. 1, when the upper wire 30 is pulled and the lower wire 30 is unwound in FIGS. 2 and 3, the distal end 20 a of the leaf spring 20 is It is deflected in the upward direction A1 along a direction substantially perpendicular to the plane of the flat plate portion 22. This is because the leaf spring 20 has low bending rigidity in a direction substantially perpendicular to the plane, not in the direction along the plane of the flat plate portion 22. As a result, as shown in FIG. 1, the distal end of the catheter 2 is deflected in the upward direction A1 from the position of the distance L3.

  2 and 3, if the lower wire 30 is pulled and the upper wire 30 is unwound, the distal end 20 a of the leaf spring 20 is substantially perpendicular to the plane of the flat plate portion 22. It is deflected in the downward direction A2 along the various directions. As a result, as shown in FIG. 1, the distal end of the catheter 2 is deflected in the downward direction A2 from the position of the distance L3.

  Therefore, the distal end of the catheter 2 can be deflected and bent in any A1 or A2 direction by operating the rotary knob of the connector 6 shown in FIG. If the connector 6 is rotated about the axis, the direction of the bending direction A1 or A2 with respect to the catheter tube 4 can be freely set while being inserted into the body cavity.

  In the electrode catheter 2 according to the present embodiment, the leaf spring 20 having the ridges 24 formed on both sides constitutes a deflection mechanism, and the leaf spring 20 is substantially perpendicular to the plane of the flat plate portion 22 of the leaf spring 20. The distal end 20a is bendable. In this catheter 2, even if the width w <b> 1 of the flat plate portion 22 in the leaf spring 20 is reduced, the spring force of the leaf spring 20 is reinforced by the ridges 24, and the restoring function after bending is excellent.

  Therefore, in this embodiment, it becomes possible to make the width | variety of the leaf | plate spring 20 small, it becomes possible to utilize effectively the cross-sectional space of the lumen 14 in which the leaf | plate spring 20 is accommodated, and the inside of the lumen | rumen is operated. It can be used as an insertion hole for the wire 30 or a wiring path. That is, the internal lumen 14 of the catheter is not blocked by the deflection mechanism, and the lumen 14 can be used effectively.

  Further, in the catheter 2 of the present embodiment, the coil spring 26 exhibits a reinforcing effect on the proximal end side of the catheter tube 4, and the leaf spring 20 exhibits a reinforcing effect on the distal end side of the catheter tube. 2 indentation characteristics are improved. Furthermore, in this catheter 2, since the deflection | deviation mechanism is comprised with the leaf spring 20 with a protruding item | line, the number of parts is reduced and the manufacture is also easy.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, the distal ends of the pair of operation wires 30 shown in FIG. 2 may be bonded to the tip electrode 10 without being bonded to the distal end 20 a of the leaf spring 20. However, the joining position of the distal ends of the pair of operation wires 30 is a position that is opposite to each other in a direction substantially perpendicular to the plane of the flat plate portion 22 in the leaf spring 20.

  Alternatively, the distal ends of the pair of operation wires 30 may be joined so as to be embedded in the distal end portion 4 a of the catheter tube 4. However, the joining position of the distal ends of the pair of operation wires 30 is a position that is opposite to each other in a direction substantially perpendicular to the plane of the flat plate portion 22 in the leaf spring 20.

  In the above-described embodiment, the catheter tube 4 does not have to be a single-layer resin tube, and may be a multilayer resin tube. Furthermore, the inner and outer peripheral surfaces of a metal leaf spring are covered with a resin. Things can be used.

  In the embodiment described above, the cross-sectional shape of the leaf spring can be variously modified. For example, as shown in FIG. 5A, a plate spring 20a in which convex strips 24a having a circular cross section are integrally formed on the front and back surfaces of the flat plate portion 22a may be used. Alternatively, for example, as shown in FIG. 5B, a leaf spring 20b in which convex ridges 24b having a circular cross section are integrally formed only on one side of the front and back surfaces of the flat plate portion 22b may be used. In the case where the protrusions 24b are integrally formed only on one side of the front and back surfaces of the flat plate portion 22b, the distance of the single operation wire 30 is only on the surface opposite to the flat plate portion 22b on which the protrusions 24b are formed. It is preferable to join the upper ends.

  Alternatively, for example, as shown in FIG. 5C, a leaf spring 20c in which convex strips 24c such as a rectangular cross section, a triangular cross section, or a polygonal cross section are integrally formed on the front and back surfaces of the flat plate portion 22c may be used. Alternatively, for example, as shown in FIG. 5 (D), a leaf spring 20d may be formed by integrally forming convex stripes 24d such as a cross-sectional rectangle, a cross-sectional triangle, or a cross-sectional polygon only on one side of the front and back surfaces of the flat plate portion 22d. In the case where the protrusions 24d are integrally formed only on one side of the front and back surfaces of the flat plate portion 22d, the distance of the single operation wire 30 is only on the surface opposite to the flat plate portion 22d where the protrusions 24d are formed. It is preferable to join the upper ends.

  Furthermore, in the present invention, as shown in FIGS. 6 and 7, a multi-lumen type catheter tube 40 having a plurality of lumens 42 to 50 may be used. In the embodiment shown in FIGS. 6 and 7, the leaf spring 20 is accommodated inside the lumen 42 located at the approximate center of the cross section of the plurality of lumens 42 to 50.

  The operation wires 30 are respectively inserted into the two lumens 44 and 46 located on both sides in the direction substantially perpendicular to the plane of the flat plate portion 22 of the leaf spring 20. The distal end of each operation wire 30 is joined to a locking piece 60 that is secured to the distal end 40 a of the catheter tube 40. The other lumens 48 and 50 may be routed through wiring from the electrodes 10 and 12 shown in FIG.

  Also in this embodiment, by pulling the operation wire 30 on the proximal end side of the catheter tube 40, the distal end of the leaf spring 20 bends in a direction substantially perpendicular to the plane of the flat plate portion 22. The distal end 40a of the catheter tube 40 also bends in the same direction. Other structures and operational effects of the embodiment shown in FIGS. 6 and 7 are the same as those of the embodiment shown in FIGS.

  Furthermore, the tip deflection operable catheter according to the present invention is not limited to the electrode catheter 2, and can be applied to catheters for other purposes.

FIG. 1 is a schematic side view of an electrode catheter according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part on the distal end side of the catheter shown in FIG. FIG. 3 is a cross-sectional view of an essential part taken along line III-III in FIG. 4 is an enlarged sectional view of the leaf spring shown in FIG. 5 (A) to 5 (D) are cross-sectional views of a leaf spring used in an electrode catheter according to another embodiment of the present invention. FIG. 6 is a perspective view of a main part of a catheter tube used in an electrode catheter according to another embodiment of the present invention. 7 is a cross-sectional view taken along the line VII-VII shown in FIG.

Explanation of symbols

2 ... Electrode catheter 4, 40 ... Catheter tube 6 ... Connector 7 ... Knob 10, 12 ... Electrode 14, 42, 44, 46, 48, 50 ... Lumen 20, 20a, 20b, 20c, 20d ... Leaf spring 22, 22a, 22b, 22c, 22d ... flat plate portion 24, 24a, 24b, 24c, 24d ... ridge 30 ... operation wire 60 ... locking piece

Claims (2)

A catheter tube having at least one lumen extending along an axial direction;
A leaf spring accommodated inside the lumen and having a ridge extending along the longitudinal direction formed from a proximal end to a distal end thereof .   The distal deflection operable catheter according to claim 1, wherein a distal end of an operation wire is connected to a distal end side of the leaf spring.

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