JP5174487B2 - catheter - Google Patents

Description

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

  In a catheter such as an electrode catheter inserted through the arterial blood vessel to the inside of the heart, the orientation of the distal end (tip) of the catheter inserted into the body is the proximal end (rear end or proximal side) of the catheter placed outside the body. It is deflected by operating the operation unit attached to (). In order to smoothly insert the catheter into a desired site, such as inside the heart, the distal end portion of the catheter needs to bend in a predetermined curve shape.

For this reason, in the conventional catheter, the resin shore D constituting the catheter tube is gradually reduced as it approaches the distal end, that is, the catheter tube is softened gradually as the catheter tube approaches the distal end. The curve shape of the distal end portion was defined. In addition, a technique for defining a curve shape by changing the interval and pitch of blades (knitting elements) and coils (reinforcing members) provided on a shaft provided in a catheter tube in a stepwise manner is known ( Patent Document 1).
JP 2006-158878 A

  In order to produce a catheter tube in which the resin shore D is changed in stages, a process such as preparing and fusing the catheter tube of each shore D is required, which is very troublesome and costly. is there.

  Further, when the intervals and pitches of the blades and coils are changed stepwise, a complicated process is required as compared with the case of creating blades and coils with equal pitches, which requires labor and cost.

  Further, there is a problem that the curve shape cannot be changed after the shaft D and the interval between the blade and the coil are once set and the shaft is manufactured.

  When a steerable (movable) structure is formed on such a shaft, it is necessary to separately provide a leaf spring or the like inside the shaft. For this reason, there are problems that the number of parts increases and the manufacturing cost increases.

  The present invention has been made in view of these problems, and an object of the present invention is to simplify the structure of a catheter whose distal end portion can be bent with a predetermined curve shape, and to reduce the manufacturing cost of the catheter. On offer.

  One embodiment of the present invention is a catheter. The catheter includes a flexible tubular member in which a plurality of lumens are formed along the axial direction, and a hollow body that is inserted into one of the plurality of lumens and has higher rigidity than the tubular member. An operating wire that is slidably inserted into the hollow body and has one end connected to the distal end of the tubular member, and the operating lumen is disposed at a position displaced from the central axis of the tubular member. The hollow body is characterized in that it has a tapered cutting surface such that the opening area becomes larger toward the distal end.

  According to this aspect, the hollow body can be gradually bent in the region where the cut surface is provided. The curvature of the distal end portion of the tubular member is similar to that of the hollow body. That is, the catheter can be bent in a certain direction with a simple structure without using the leaf spring used in the conventional catheter. As a result, the manufacturing cost of the catheter can be reduced.

  In the catheter of the above aspect, the opening region may be formed in a direction connecting the central axis of the tubular member and the central axis of the hollow body. Further, the outer peripheral surface of the hollow body may be in contact with the inner surface of the operating lumen.

  The hollow body is positioned on the proximal end side, is positioned between the first region having a relatively high flexibility, and between the first region and the cut surface, and is more flexible than the first region. And a second region having a low height. In this case, the first region of the hollow body may be coiled. Furthermore, the tubular member may have a reinforcing member embedded in the outer peripheral portion from the proximal end side to a predetermined position, and the distal end of the tubular member may be in the second region of the hollow body.

  A combination of the above-described elements as appropriate can also be included in the scope of the invention for which patent protection is sought by this patent application.

  ADVANTAGE OF THE INVENTION According to this invention, the structure of the catheter which can curve a distal end part by a predetermined curve shape can be simplified, and the manufacturing cost of a catheter can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same constituent elements are denoted by the same reference numerals, and detailed description thereof will be appropriately omitted in the following description.

(Embodiment 1)
The catheter according to Embodiment 1 is an electrode catheter capable of tip deflection operation, and is suitably used for diagnosis or treatment of arrhythmia in the heart, for example.

  1 is a side view of a catheter according to Embodiment 1. FIG. FIG. 2 is a top view of the catheter according to the first embodiment. As shown in FIGS. 1 and 2, the catheter 2 according to Embodiment 1 has a tip electrode 10 and ring-shaped electrodes 12 a and 12 b at the distal end of the tubular member 4. The tip electrode 10 and the ring-shaped electrodes 12a and 12b are fixed to the tubular member 4 using, for example, an adhesive.

  A handle 6 is attached to the proximal end of the tubular member 4. From the handle 6, a lead wire for a lead wire electrically connected to the tip electrode 10 and the ring electrodes 12a and 12b is drawn. The handle 6 is equipped with a knob 7 for performing a deflection movement operation (swing operation) of the distal end portion of the tubular member 4.

  As will be described later, the tubular member 4 has a hollow structure having a plurality of lumens formed along the axial direction. The distal end portion of the tubular member 4 is relatively flexible and the proximal end portion of the tubular member 4 is relatively rigid.

  The main part of the tubular member 4 is made of a synthetic resin such as polyolefin, polyamide, polyether polyamide, or polyurethane. The outer diameter of the tubular member 4 is generally about 0.6 to 3 mm. As will be described later, the lumen formed in the axial direction of the tubular member 4 is passed through the insulated wires connected to the tip electrode 10 and the ring-shaped electrodes 12a and 12b shown in FIGS. Has been.

  The tip electrode 10 and the plurality of ring-shaped electrodes 12a and 12b are made of a metal having good thermal conductivity, such as aluminum, copper, stainless steel, gold, or platinum. In order to provide a good contrast property for X-rays, the tip electrode 10 and the ring electrodes 12a and 12b are preferably made of platinum or the like. The outer diameter of the tip electrode 10 and the ring-shaped electrodes 12a and 12b is not particularly limited, but is preferably about the same as the outer diameter of the tubular member 4, and is usually about 0.5 to 3 mm.

  3 is a cross-sectional view of the catheter according to Embodiment 1 on the line BB in FIG. 4 is a cross-sectional view taken along the line CC of FIG. 1 in the catheter according to Embodiment 1. FIG. 5 is a cross-sectional view taken along the line DD of FIG. 2 in the catheter according to the first embodiment.

  As shown in FIGS. 3 to 5, the tubular member 4 is formed with a first lumen 20, a second lumen 22, a third lumen 24, and a fourth lumen 26 along the axial direction. The first lumen 20 is provided at a position facing the second lumen 22 across the central axis 21 of the tubular member 4. That is, the first lumen 20 is provided at a position shifted from the central axis 21 of the tubular member 4. The third lumen 24 is provided at a position facing the fourth lumen 26 across the central axis 21 of the tubular member 4. In the present embodiment, the line connecting the first lumen 20 and the second lumen 22 intersects with the line connecting the third lumen 24 and the fourth lumen 26. The diameters of the first lumen 20 and the second lumen 22 are about 0.1R to 0.45R, where R is the diameter of the tubular member 4. The diameters of the third lumen 24 and the fourth lumen 26 are approximately 0.1R to 0.45R, where R is the diameter of the tubular member 4.

  A pipe 30 is inserted through the first lumen 20. The pipe 30 is a hollow body made of a material having higher rigidity than the tubular member 4 such as SUS or NiTi. Details of the pipe 30 will be described later. An operation wire 40 is slidably inserted through the lumen of the pipe 30. A spherical anchor 42 having a larger diameter than the operation wire 40 in the pipe 30 is formed at the distal end of the operation wire 40. The proximal end of the operation wire 40 is connected to the knob 7 shown in FIGS. 1 and 2.

  As shown in FIG. 4, a recess 50 is formed inside the tip electrode 10. The recess 50 is filled with solder 60. The distal end of the operation wire 40 is embedded in the solder 50, and the distal end of the operation wire 40 is fixed to the solder 60 and the tip electrode 10. Accordingly, by operating the knob 7 shown in FIGS. 1 and 2, the operation wire 40 is pulled, and the distal end of the catheter 2 can be swung in the direction of arrow A in FIGS. 2 and 4. . In the present embodiment, since the anchor 42 is provided at the distal end of the operation wire 40, the distal end of the operation wire 40 is difficult to come out of the solder 60. Thereby, the operation reliability of the catheter 2 can be improved.

  As shown in FIG. 4, a conducting wire 70 is inserted through the second lumen 22. The distal end of the conductor 70 is embedded in the solder 60. Thereby, the conducting wire 70 and the tip chip electrode 10 are electrically connected via the solder 60.

  Further, as shown in FIG. 5, a conducting wire 80 is inserted through the third lumen 24. The distal end of the conducting wire 80 is fixed to the ring-shaped electrode 12 a through an opening 13 a formed in the tubular member 4. The distal end of the conducting wire 80 is fixed to the ring-shaped electrode 12a using, for example, welding or soldering. Thereby, the conducting wire 80 and the ring-shaped electrode 12a are electrically connected.

  A conducting wire 84 is inserted through the fourth lumen 26. The distal end of the conducting wire 84 is fixed to the ring-shaped electrode 12 b through the opening 13 b formed in the tubular member 4. The distal end of the conducting wire 84 is fixed to the ring-shaped electrode 12b using, for example, welding or soldering. Thereby, the conducting wire 84 and the ring-shaped electrode 12b are electrically connected.

  FIG. 6 is a side view of the distal end portion of the pipe 30. FIG. 7 is a perspective view of the distal end portion of the pipe 30. As shown in FIGS. 6 and 7, the pipe 30 has a cut surface 33 directed in a certain direction at a distal end portion thereof. From the start point 34 of the cut surface 33 to an end point 35 located at a predetermined distance R1 (for example, mm) (hereinafter referred to as region R1), the cut surface 33 is tapered with respect to the axis of the pipe 30. The opening area of the cutting surface 33 increases as it approaches the distal end. In other words, in the region R <b> 1, the length of the arc of the cross section of the pipe 30 in the plane orthogonal to the axis of the pipe 30 is gradually shortened as it approaches the distal end of the pipe 30.

  In the region R2 from the end point 35 to the distal end of the pipe 30 located at a predetermined distance R2 (for example, 5 to 300 mm), the length of the arc of the cross section of the pipe 30 in the plane orthogonal to the axis of the pipe 30 is It is constant. Thereby, the bendability (curve shape) of the pipe 30 in the region R2 can be kept constant.

  As a result, the pipe 30 is more easily bent toward the distal end portion. Furthermore, since the cutting surface 43 is tapered in the region R1 of the pipe 30, the pipe 30 is gradually bent in the region R1 when the distal end portion of the pipe 30 is bent. That is, when the distal end portion of the pipe 30 is bent, the radius of curvature of the curve of the pipe 30 gradually decreases in the region R1. The curve shape of the pipe 30 in the region R1 can be freely designed according to the taper angle of the cut surface 33 in the region R1. Moreover, since the cutting surface 33 provided at the distal end portion of the pipe 30 faces a certain direction, the bending direction of the pipe 30 is limited to the certain direction.

  In the catheter 2 of the present embodiment, the cut surface 33 of the pipe 30 is inserted through the first lumen 20 so as to be directed to the central axis of the tubular member 4 shown in FIG. Thereby, the curvature of the distal end portion of the tubular member 4 is the same as that of the pipe 30. That is, the catheter 2 can be bent in a certain direction without using the leaf spring used in the conventional catheter. In other words, the flatness of the curve when the catheter 2 is bent can be improved. It is desirable that the outer diameter of the pipe 30 matches the inner diameter of the first lumen 20. According to this, since the pipe 30 is suppressed from being displaced in the first lumen 20 when the catheter 2 is bent, the curve shape of the catheter 2 can be maintained in a desired state.

  The pipe 30 may be fixed to the inner wall of the first lumen 20 using an adhesive or the like. In this case, it is desirable to fix the distal end and the proximal end of the pipe 30 to the inner wall of the first lumen 20 using an adhesive or the like.

(Embodiment 2)
FIG. 8 is a cross-sectional view of the catheter 2 according to the second embodiment. As shown in FIG. 8, in the catheter 2 of the second embodiment, a blade 90 is embedded as a reinforcing member in the outer peripheral portion of the tubular member 4 from the proximal end side of the tubular member 4 to a predetermined position. Thereby, by using a highly flexible material as the tubular member 4, the distal end portion of the tubular member 4 can be easily bent, and the rigidity on the proximal end side of the tubular member 4 can be increased.

  The blade 90 may be formed of a metal such as stainless steel, tungsten, gold, titanium, silver, copper, platinum, or iridium, or an alloy of these metals. The blade 90 may be formed of a non-metallic material, for example, polyparaphenylene terephthalamide fiber, liquid crystal polymer fiber, or glass fiber.

  FIG. 9 is a side view of the pipe 30 used in the catheter 2 according to the second embodiment. As shown in FIG. 9, in the pipe 30 according to the second embodiment, coils 36 having a predetermined pitch are formed in a region R3 from the proximal end side to a predetermined position 37. In the region R4 from the position 37 to the start point 34, the pipe 30 is formed with a cylindrical hollow body. Thereby, the flexibility of the pipe 30 is increased in the region R3, and the pipe 30 is easily bent. The ease of bending of the pipe 30 can be easily changed by adjusting the pitch of the coil 36 and the width of the coil 36. Note that the length of the region R4 is, for example, 10 mm.

  FIG. 10 is a diagram illustrating a positional relationship between the blade 90 and the pipe 30 used in the catheter 2 according to the second embodiment. In the catheter of the second embodiment, as shown in FIG. 10, the distal end 91 of the blade 90 is located within the region R <b> 4 of the pipe 30. According to this, since the proximal end side of the pipe 30 is coiled, the pipe 30 becomes flexible and is easily bent. On the other hand, since the cut surface 33 is formed on the distal end side of the pipe 30, directionality is created without using a member such as a leaf spring. Furthermore, the distal end 91 of the blade 90 serves as a fulcrum, and a curve with an appropriate curvature can be formed in the pipe 30 from the distal end 91 to the tip. Depending on the curved shape of the pipe 30, the distal end portion of the catheter is curved. By shifting the position of the distal end 91 of the blade 90 within the region R4 of the pipe 30, the curve shape of the catheter tip can be adjusted.

(Embodiment 3)
FIG. 11 is a side view of a distal end portion of a pipe incorporated in the catheter according to the third embodiment. FIG. 12 is a perspective view of a distal end portion of a pipe incorporated in the catheter according to the third embodiment. In the first embodiment and the second embodiment, the length of the arc of the cross section of the pipe 30 in the plane orthogonal to the axis of the pipe 30 is constant in the region R2 of the pipe 30, but the shape of the pipe 30 in the region R2 Is not limited to this. For example, as shown in FIGS. 11 and 12, the distal end portion of the pipe 30 may be a cylindrical hollow body in the region R2.

  According to this, in the region R1 of the pipe 30, it is possible to ensure the strength in the region R2 corresponding to the tip portion of the pipe 30 while ensuring the desired curve shape and the directionality of the curve. By using this pipe 30, the kink resistance of the catheter can be improved with a simple configuration.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The form can also be included in the scope of the present invention.

  For example, in Embodiment 1 described above, the pipe 30 is fixed to the inner wall of the first lumen 20, but the pipe 30 may be detachable from the first lumen 20. In this case, it is desirable that the outer diameter of the pipe 30 matches the inner diameter of the first lumen 20 as described above. According to this, when the distal end portion of the catheter 2 does not have a desired curved shape, the pipe 30 is taken out from the first lumen 20, and the position and angle of the cutting surface 33 of the pipe 30 are changed. The curve shape of 2 can be adjusted. For this reason, compared with the conventional catheter, while being able to set a curve shape easily, the cost for making the distal end part of a catheter into a desired curve shape can be reduced.

  In the second embodiment described above, the coil is formed to make the proximal end side of the pipe 30 easy to bend, but the structure for making the proximal end side of the pipe 30 easy to bend is not limited to this. . For example, a slit having a predetermined pitch may be provided on the proximal end side of the pipe 30.

  Moreover, in the catheter of each embodiment described above, the cutting surface 33 of the pipe 30 is directed to the central axis of the tubular member 4 and is inserted through the first lumen 20, but the cutting surface 33 of the pipe 30 is the tubular member. You may face the other side with respect to the central axis of 4. Also by this, the catheter 2 can be bent in a certain direction without using the leaf spring used in the conventional catheter.

  In the catheters of the above-described embodiments, the number of operation wires 40 is one. However, the pipe 30 and the operation wire are arranged on the lumen located on the opposite side of the first lumen 20 with the central axis of the tubular member 4 interposed therebetween. A structure similar to that of the wire 40 may be provided. According to this, the direction of deflection of the catheter can be bidirectional.

1 is a side view of a catheter according to Embodiment 1. FIG. 2 is a top view of the catheter according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view taken along the line BB in FIG. 1 in the catheter according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line CC of FIG. 1 in the catheter according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line DD in FIG. 2 in the catheter according to the first embodiment. FIG. 6 is a side view of a distal end portion of a pipe that is inserted through a first lumen. It is a perspective view of the distal end part of the pipe penetrated by the 1st lumen. 6 is a cross-sectional view of a catheter according to Embodiment 2. FIG. The cross-sectional view corresponds to a cross-sectional view taken along the line CC in FIG. 6 is a side view of a pipe used in the catheter 2 according to Embodiment 2. FIG. It is a figure which shows the positional relationship of the braid | blade used for the catheter which concerns on Embodiment 2, and a pipe. It is a side view of the distal end part of the pipe integrated in the catheter which concerns on Embodiment 3. It is a perspective view of the distal end part of the pipe integrated in the catheter which concerns on Embodiment 3. FIG.

Explanation of symbols

1 catheter, 4 tubular member, 10 tip electrode, 12 ring electrode, 20 first lumen, 22 second lumen, 24 third lumen, 26 fourth lumen, 30 pipe, 40 operation wire.

Claims (6)

A flexible tubular member having a plurality of lumens formed along the axial direction;
A hollow body that is inserted into any one of the plurality of lumens and has higher rigidity than the tubular member;
An operating wire that is slidably inserted into the hollow body and has one end connected to the distal end of the tubular member;
With
The operating lumen is disposed at a position displaced from a central axis of the tubular member;
The said hollow body has a taper-shaped cut surface which becomes large in an opening area | region as it approaches a distal end, The catheter characterized by the above-mentioned.   The catheter according to claim 1, wherein the open region is formed in a direction connecting a central axis of the tubular member and a central axis of the hollow body.   The catheter according to claim 1 or 2, wherein an outer peripheral surface of the hollow body is in contact with an inner surface of the operation lumen.   The hollow body is located on the proximal end side, is located between the first region having relatively high flexibility, and between the first region and the cut surface, and compared to the first region. The catheter according to any one of claims 1 to 3, further comprising a second region having low flexibility.   The catheter according to claim 4, wherein the first region of the hollow body is coiled. The tubular member has a reinforcing member embedded in the outer peripheral portion from the proximal end side to a predetermined position,
6. A catheter according to claim 4 or 5, wherein the distal end of the tubular member is in the second region of the hollow body.

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