HK1135300B - Electrode catheter - Google Patents

Description

Electrode catheter

Technical Field

The present invention relates to an electrode catheter having an electrode at a distal end portion of the catheter.

Background

The beating of the heart is performed by sequentially stimulating the muscles of the heart with electrical signals that periodically occur from a portion of the heart. However, when the flow of the electrical signal is abnormal, the heart cannot beat correctly. This is called a heart disease.

As a medical device used for diagnosing or treating irregular pulsation of the heart, an electrode catheter is known. The electrode catheter is generally composed of a catheter main body, a control handle connected to a proximal end side of the catheter main body, and a catheter tip connected to a distal end side of the catheter main body, and a plurality of ring-shaped electrodes are attached to an outer peripheral surface of the catheter tip.

When diagnosing irregular pulsation of the heart using such an electrode catheter, the electrode catheter is inserted into a blood vessel from the distal end portion of the catheter, and the distal end portion of the catheter is pushed against the inner wall of the heart, whereby the potential inside the heart is measured. Therefore, it is important that the catheter tip has a shape that can be fitted to the measurement site.

Conventionally, as an electrode catheter for measuring a potential at a site such as a pulmonary vein of a heart, an electrode catheter having a catheter tip portion formed in a ring shape has been proposed (for example, see patent document 1). By forming the distal end of the catheter into a ring shape, the inner peripheral portion of the blood vessel can be measured simultaneously in the radial direction.

Fig. 13 is a perspective view showing the shape of a catheter distal end portion (image assembly) constituting the electrode catheter of patent document 1, in which the catheter distal end portion 90 is constituted by a linear proximal end side region 91, an annular main body region 92, and a linear distal end side region 93, and is connected to the distal end side of a catheter main body 95.

A main body region 92 of the catheter tip portion 90 is formed in a ring shape, and a plurality of ring-shaped electrodes (not shown) are attached to the main body region 92.

The distal end side region 93 of the distal end portion 90 is formed by a strongly wound coil spring made of stainless steel, and is formed linearly. The distal end region 93 (coil spring) functions as a small guide cord, and a ring electrode is not attached.

Patent document 1: japanese unexamined patent publication No. 2003-111740

However, the catheter described in patent document 1 has the following problems.

(1) The distal end region of the distal end of the catheter functions as a guide wire, and since the ring-shaped electrode is not attached to the distal end region, the potential cannot be measured in the distal end region.

(2) The distal end side region of the catheter distal end portion is formed by a linearly extending coil spring, and the blood vessel may be damaged by the distal end thereof or when the distal end is pressed or rubbed against the inner wall of the blood vessel. For example, when the catheter is pushed (screwed) into the blood vessel so that the distal end portion (main body region) of the catheter reaches the measurement site, the inner wall of the blood vessel is damaged by the distal end of the coil spring, and in such a case, the distal end of the coil spring may pierce the blood vessel wall. When the distal end portion of the catheter is rotated with the distal end of the coil spring as a fulcrum (in a state where the inner wall of the blood vessel is pressed by the distal end), the pressed portion of the distal end portion may be damaged.

Disclosure of Invention

The present invention has been developed based on the above-described matters.

A first object of the present invention is to provide an electrode catheter which can measure an electric potential in substantially the entire region of a catheter tip portion and which does not damage an inner wall of a blood vessel by the tip portion of the catheter tip portion.

Further, a second object of the present invention is to provide an electrode catheter having high measurement accuracy.

An electrode catheter according to a first aspect of the present invention includes: a catheter body having at least one internal bore; a control handle attached to a proximal end side of the catheter main body; the catheter tip portion is formed in a circular ring shape, is connected to the tip end side of the catheter main body, has an inner hole communicating with at least one of the inner holes of the catheter main body, and has a plurality of ring-shaped electrodes attached to the outer periphery thereof and a spherical chip electrode attached to the tip end thereof.

In addition, an electrode catheter according to a second aspect of the present invention includes: a catheter body having at least one internal bore; a control handle attached to a proximal end side of the catheter main body; a catheter tip portion connected to the tip end side of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and formed in an elliptical ring shape; and a plurality of ring-shaped electrodes attached to the outer periphery of the distal end portion of the catheter.

In addition, an electrode catheter according to a third aspect of the present invention includes: a catheter body having at least one internal bore; a control handle attached to a proximal end side of the catheter main body; a catheter tip portion connected to the tip end side of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and formed in a circular ring shape; a plurality of ring-shaped electrodes attached to an outer periphery of a distal end portion of the catheter; and a deflecting means for deflecting the distal end portion of the catheter main body such that the center of a circle, which is a ring shape of the distal end portion of the catheter, is separated from a plane including a direction in which the distal end portion of the catheter main body is deflected.

In addition, an electrode catheter according to a fourth aspect of the present invention includes: a catheter body having at least one internal bore; a control handle attached to a proximal end side of the catheter main body; a catheter tip portion connected to the tip end side of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and formed in a spiral shape; a plurality of ring-shaped electrodes attached to an outer periphery of a distal end portion of the catheter; and a deflecting mechanism for deflecting the distal end portion of the catheter main body such that a central axis of a spiral of the distal end portion of the catheter is separated from a plane including a direction in which the distal end portion of the catheter main body is deflected.

In the electrode catheter according to the first aspect of the present invention, it is preferable that the electrode catheter further includes a deflecting mechanism for deflecting the distal end portion of the catheter.

In the electrode catheter of the second aspect of the present invention, it is preferable that the catheter tip portion includes a deflecting mechanism for deflecting the catheter tip portion in the minor axis direction of the ellipse which is the loop shape.

In the electrode catheters according to the second to fourth aspects of the invention, a spherical chip electrode may be attached to the tip of the tip portion of the catheter.

In the electrode catheter of the present invention, it is preferable that the diameter of the spherical chip electrode is larger than the outer diameter of the catheter tip. Specifically, the ratio (D/D) of the diameter (D) of the spherical chip electrode to the outer diameter (D) of the catheter tip is preferably 1.05 or more.

In the electrode catheter of the first aspect of the present invention, since the plurality of ring-shaped electrodes are attached to the outer periphery of the catheter tip portion and the spherical chip electrode is attached to the tip portion, the potential can be measured substantially over the entire region of the catheter tip portion.

Further, since the chip electrode is spherical, when the chip electrode is pressed (screwed) into the blood vessel with the tip, the risk of damaging the inner wall of the blood vessel is extremely low even if the inner wall of the blood vessel is pressed or scraped by the chip electrode. Therefore, the electrode catheter can be safely and smoothly advanced to the target site.

Further, even if the tip portion of the catheter is rotated with the spherical chip electrode as a fulcrum, the risk of damage to the inner wall (the portion pressed by the chip electrode) positioned at the fulcrum is extremely low. In this way, the tip portion of the catheter can be rotated with the chip electrode as a fulcrum, and thus a wide range of potential can be continuously and safely measured.

Further, the spherical chip electrode can be easily recognized in an X-ray image, and thus the entire position, state, and the like of the catheter tip portion can be easily grasped.

According to the electrode catheter of the second aspect of the present invention, the accuracy of measuring the potential can be improved. That is, since the cross-sectional shape of the pulmonary vein is not strictly circular but is elliptical, the tip of the catheter having an elliptical ring shape is more suitable for the inner wall of the pulmonary vein, and the distance from the inner wall of the pulmonary vein to the ring-shaped electrode is substantially constant without any difference between the ring-shaped electrodes, so that the accuracy of measuring the potential is improved as compared with a circular ring.

In addition, according to the electrode catheter of the second aspect of the present invention, which is provided with the deflection mechanism for deflecting the catheter tip portion in the minor axis direction of the ellipse, which is the loop shape thereof, the elliptical shape of the catheter tip portion can be recognized in the X-ray image, and therefore, the operation can be performed in accordance with the deflection direction (the minor axis direction of the ellipse).

According to the electrode catheter of the third and fourth aspects of the present invention, when the distal end portion of the catheter is moved while being pushed into the inner wall of the blood vessel, the loop shape of the distal end portion of the catheter is less likely to collapse, and the accuracy of measuring the potential is improved.

According to the electrode catheter of the present invention in which the ratio (D/D) is 1.05 or more, the tip surface of the catheter tip is sufficiently covered with the chip electrode, and contact between the tip surface (tip edge) of the catheter tip and the inner wall of the blood vessel can be reliably avoided. Further, since the spherical chip electrode has a relatively large surface area, the potential can be easily obtained, and the measurement can be performed even if the chip electrode is separated from the measurement site (inner wall) to some extent.

Drawings

FIG. 1 is a perspective view showing an embodiment of an electrode catheter of the present invention;

FIG. 2 is a partially enlarged perspective view of FIG. 1;

FIG. 3 is an explanatory view of the electrode catheter shown in FIG. 1 viewed from the front end side;

FIG. 4 is a perspective view showing a state in which the catheter distal end portion of the electrode catheter shown in FIG. 1 is deflected (about 180 °);

FIG. 5 is an explanatory view showing a state in which the catheter distal end portion of the electrode catheter shown in FIG. 1 is deflected (about 90 °), where (a) is a front view and (b) is a side view;

FIGS. 6 to 8 are explanatory views showing a state of use of the electrode catheter shown in FIG. 1;

FIG. 9 is a sectional view schematically showing the internal structure of the electrode catheter shown in FIG. 1;

FIG. 10 is an enlarged partial cross-sectional view of FIG. 9;

FIG. 11 is a schematic view showing the overall configuration of a catheter system including the electrode catheter shown in FIG. 1;

fig. 12 is an explanatory view of an electrode catheter of another embodiment of the present invention, viewed from the front end side;

fig. 13 is a perspective view showing the shape of the catheter tip constituting a conventional electrode catheter.

Description of the symbols:

1. electrode catheter

2. Electrode catheter

10. Catheter body

20. Control handle

30. Front end of catheter

11. First pipe

12. Second pipe

21. Handle bar

22. Rotary knob

33. Third pipe

31. Ring electrode

32. Chip electrode

41. Pull rope

42. Plate spring

43. First spiral pipe

44. Second spiral pipe

51. Core wire

61. Lead wire

62. Connector with a locking member

63. Cable with a protective layer

64. Electrocardiogram instrument

65. Monitor with a display

70. Front end of catheter

Detailed Description

FIG. 1 is a perspective view showing an embodiment of an electrode catheter of the present invention, FIG. 2 is a partially enlarged perspective view of FIG. 1, FIG. 3 is an explanatory view of the electrode catheter shown in FIG. 1 viewed from the front end side, FIG. 4 is a perspective view showing a state in which the catheter tip portion of the electrode catheter shown in FIG. 1 is deflected (about 180 ℃ C.), FIG. 5 is an explanatory view showing a state in which the catheter distal end portion of the electrode catheter shown in FIG. 1 is deflected (about 90 °), where (a) is a front view, (b) is a side view, FIGS. 6 to 8 are explanatory views showing a state of use of the electrode catheter shown in FIG. 1, FIG. 9 is a sectional view schematically showing an internal structure of the electrode catheter shown in FIG. 1, fig. 10 is a partially enlarged sectional view of fig. 9, fig. 11 is a schematic view showing the entire configuration of a catheter system including the electrode catheter shown in fig. 1, and fig. 12 is an explanatory view of the electrode catheter according to another embodiment of the present invention as viewed from the front end side.

[ first embodiment ]

The electrode catheter 1 of the present embodiment includes a catheter main body 10, a control handle 20, and a catheter tip portion 30 formed in a circular ring shape.

The catheter body 10 is an elongated tubular structure having an inner bore, and is composed of a first tube 11 and a second tube 12.

The first pipe 11 is required to have a certain flexibility (bendability), non-compressibility in the pipe axial direction, and torsional rigidity. The torsional rigidity of the first tube 11 allows the rotational torque from the control handle 20 to be transmitted to the catheter tip portion 30.

The first pipe 11 is not particularly limited, and may be a braided pipe formed by braiding a pipe made of a resin such as polyurethane, nylon, or PEBAX (ポリエ - テルブロツクアミド: polyether amide block copolymer) with a stainless steel wire.

The length of the first pipe 11 is set to 50 to 200cm, for example.

The second tube 12 is a tube constituting the distal end portion of the catheter main body 10, has an inner hole communicating with the inner hole of the first tube 11, and is bent by a biasing mechanism (a plate spring disposed in the inner hole) described later.

As a constituent material of the second tube 12, a nontoxic resin can be used. The second tube 12 is not woven, and is therefore more flexible than the first tube 11.

The length of the second pipe 12 is set to 3 to 10cm, for example, and more preferably 4 to 7 cm.

The outer diameter of the catheter main body 10 (the first tube 11 and the second tube 12) is preferably set to 2.6mm or less, more preferably 2.4mm or less, and particularly preferably 2.3 to 2.4 mm.

The inner diameter of the catheter body 10 is preferably in the range of 1.5 to 1.7mm when the outer diameter is 2.3 to 2.4mm, for example, from the viewpoint of securing a housing space for a cord, a lead wire, or the like and securing torsional rigidity (wall thickness).

The control handle 20 is connected to the proximal end side of the catheter main body 10 (first tube 11). In fig. 1, 21 is a handle, and 22 is a knob.

By rotating the control handle 20, the rotational torque is transmitted to the catheter tip portion 30 via the catheter main body 10.

As shown in fig. 4, the second tube 12 is bent by a deflection mechanism described later by sliding the knob 22 on the proximal end side, and the catheter distal end portion 30 is deflected accordingly.

Therefore, by operating the control handle 20, the catheter distal end portion 30 is rotated and further deflected, whereby the catheter distal end portion 30 can be guided to the target site.

The catheter distal end portion 30 is configured such that a third tube 33 connected to the distal end side of the catheter main body 10 (second tube 12) is formed in a circular ring shape.

9 ring-shaped electrodes 31 are attached to the outer peripheral surface of the catheter tip portion 30 (third tube 33). Further, a spherical chip electrode 32 is attached to the tip of the catheter tip 30.

As shown in fig. 3, the third tube 33 constituting the catheter tip portion 30 is formed in a substantially circular ring shape. This makes it possible to measure the inner peripheral portion of the blood vessel in the radial direction at the same time. The catheter distal end portion 30 is not a flat circular closed loop, but a spiral loop having the chip electrode 32 as the leading end (in the present invention, when referred to as "circular" or "elliptical", the spiral shape is strictly included). Thus, the blood vessel can be easily advanced toward the target site.

The third tube 33 constituting the catheter tip portion 30 has an inner hole communicating with the inner hole of the catheter main body 10 (second tube 12).

Examples of the material of the third tube 33 include a biocompatible resin material such as polyurethane or PEBAX.

The ring electrode 31 attached to the catheter tip portion 30 is made of a conductive material such as platinum, gold, iridium, or an alloy thereof. The method of attaching the ring electrode 31 is not particularly limited, and examples thereof include a method of fixing a metal material formed into a ring shape to the third pipe 33 with an adhesive, and a method of forming a film into a ring electrode by sputtering, ion beam deposition, or the like.

In addition, it is needless to say that the number of the ring-shaped electrodes 31 is not limited to 9.

The number of the ring-shaped electrodes 31 is preferably 6 to 20, and more preferably 8 to 12.

The electrode catheter 1 of the present embodiment has a feature that a spherical chip electrode 32 is attached to the tip of a catheter tip portion 30 formed in a circular ring shape.

Thus, substantially the entire region of the catheter tip 30, i.e., the region from the ring electrode 31 located on the most proximal end side to the tip on which the chip electrode 32 is mounted, can be set as the potential measurement region.

Further, since the chip electrode 32 is spherical, even if the chip electrode 32 is used or pressed or rubbed against the inner wall of the blood vessel, the blood vessel is not damaged.

For example, as shown in fig. 6, when the electrode catheter 1 is pressed (screwed) into the pulmonary vein P, the inner wall of the pulmonary vein P is pressed or wiped by the chip electrode 32, but since the chip electrode 32 is spherical, the risk of damage to the inner wall is extremely low, and the motor catheter 1 can be advanced safely and smoothly.

In fig. 6, arrow a indicates the pressing direction of the electrode catheter 1, and arrow B indicates the normal rotation direction during pressing.

As shown in fig. 7, even if the spherical chip electrode 32 is used as a fulcrum, or the catheter tip 30 is rotated, or the diameter of the loop is enlarged or reduced, the inner wall S (the portion pressed by the chip electrode 32) positioned at the fulcrum is extremely low in risk of being damaged. In this way, the rotation of the catheter tip portion 30 can be performed using the chip electrode 32 as a fulcrum, and thus a wide range of potential can be continuously and safely measured.

As shown in fig. 8, even if a rotational torque is applied to the direction (direction indicated by arrow C) for expanding the ring diameter of the catheter tip 30 with the spherical chip electrode 32 as a fulcrum so that the ring-shaped electrode 31 is brought into contact with or close to the inner wall of the pulmonary vein P, the risk of damage to the inner wall S at the fulcrum is extremely low, and this type of diameter expansion operation of the catheter tip can be safely performed.

The diameter (D) of the spherical chip electrode 32 is preferably set to 1.5 to 2.0mm, and particularly preferably set to 1.8 mm.

The diameter (D) of the chip electrode 32 needs to be larger than the outer diameter (D) of the catheter tip portion 30, and specifically, is preferably 1.05 times or more, more preferably 1.05 to 2.5 times the outer diameter (D) of the catheter tip portion 30.

Since the ratio (D/D) is 1.05 or more, the distal end surface of the catheter distal end portion 30 can be sufficiently covered with the chip electrode 32, the distal end edge of the catheter distal end portion 30 can be reliably prevented from being exposed and coming into contact with the blood vessel inner wall, and the effect of preventing injury can be reliably ensured.

Further, since the ratio (D/D) is 1.05 or more, the spherical chip electrode 32 has a relatively large surface area, and thus the potential can be easily obtained, and the potential can be measured even if it is separated from the measurement site (inner wall) to some extent.

As shown in fig. 5, when the catheter tip portion 30 is viewed from the front in a state in which the second tube 12, which is the tip portion of the catheter main body 10, is bent, the second tube 12 extends away from the center of a circle, which is the ring shape of the catheter tip portion 30 (in the figure, the center axis of the second tube 12 indicated by a dotted line is away from the center line of the circle indicated by a dotted line), as shown in fig. 5 a. That is, the imaginary plane containing the bent second tube is deviated from the center of the ring shape, i.e., the circle.

In other words, when the second tube 12 is bent, the center of the circle, which is the ring shape of the conduit distal end portion 30, moves parallel to a virtual plane including the direction in which the second tube 12 is bent. That is, an imaginary plane including the bending direction of the second tube 12 does not intersect with the ring shape, i.e., the center of the circle.

In fig. 5(a), the catheter tip portion 30 extends clockwise from the second tube 12 and forms a circular loop. In this case, an imaginary plane including the bending direction of the second tube 12 is located on the right side (right side as viewed from the front of the catheter tip portion 30) with respect to the center of the ring shape, i.e., the circle.

The catheter tip portion 30 has a spiral shape in a strict sense. That is, the catheter tip portion 30 is formed into a spiral (left-handed, zigzag-wound) to the left (a spiral extending clockwise from the second tube 12). The center axis of the spiral of the catheter tip portion 30 is designed to be away from an imaginary plane including the direction in which the second tube 12 is bent. That is, the central axis of the spiral of the catheter tip portion 30 moves parallel to an imaginary plane including the direction in which the second tube 12 bends.

In this case, an imaginary plane including the direction in which the second tube 12 is bent is located on the right side (right side as viewed from the front of the duct distal end portion 30) with respect to the center axis of the spiral of the duct distal end portion 30.

When the winding direction of the circular ring of the catheter tip portion 30 is reversed (when the circular ring is formed by extending counterclockwise from the second tube 12), the virtual plane including the direction in which the second tube 12 is bent is located on the left side of the center of the ring shape, i.e., the circle.

When the spiral of the duct tip portion 30 is a right spiral (right-handed, S-wound), an imaginary plane including the direction in which the second tube 12 is bent is located on the left side of the central axis of the spiral of the duct tip portion 30.

By forming such a shape (a shape extending from a point on the ring shape, i.e., the circumference, to the center of the circle when viewed from the front of the catheter distal end portion 30 and connecting the second tube 12), for example, when the ring-shaped catheter distal end portion 30 is moved (the electrode catheter 1 is inserted) while pressing the inner wall of the blood vessel or the like in a state where the second tube 12 is bent, deformation of the catheter distal end portion 30 such as opening of the ring is less likely to occur. This is because when the catheter distal end portion 30 is pressed against the inner wall of a blood vessel or the like, the pressing force is transmitted to the proximal end portion (portion having relatively high rigidity) of the catheter distal end portion 30.

When the direction of the pressing force is slightly inclined when the tip portion (second tube) of the catheter main body extends through the center of the circle, which is the ring shape of the catheter tip portion, when viewed from the front of the catheter tip portion (when the center of the circle is on the virtual plane), the tip portion of the catheter tip portion is also subjected to the pressing force, and the ring is easily opened.

In the present embodiment, when the radius of the circle is set to (r) as the distance (p) from the center axis of the second pipe 12 to the center line of the circle, it is preferably 0.01r to 0.8 r.

As shown in fig. 9 and 10, the electrode catheter 1 of the present embodiment includes a deflecting mechanism for deflecting the catheter tip portion 30. The biasing mechanism includes a pull rope 41 and a leaf spring 42. In fig. 9, the catheter distal end portion 30 is linearly illustrated as a ring shape.

The pulling rope 41 constituting the biasing mechanism extends through the inner hole of the catheter main body 10. The base end portion 41B of the cord 41 is fixed inside the control handle 20. The control handle 20 is provided with a piston mechanism (not shown) that moves (pulls) the pull cord 41 toward the proximal end side by sliding the knob 22 toward the proximal end side from the state shown in fig. 9. On the other hand, the tip end portion 41A of the pull cord 41 is fixed to the tip end portion of the leaf spring 42.

Examples of the material of the cord 41 include stainless steel and Ni — Ti alloy. The surface of the pull cord 41 is preferably covered with PTFE [ teflon (registered trademark) ] or the like. The diameter of the pull cord 41 may be set to 0.1 to 0.5mm, for example.

The base end of the plate spring 42 constituting the biasing mechanism is fixed to the front end of the first solenoid 43.

The first spiral pipe 43 is formed by winding a wire material having a right-angled or circular cross section in a coil shape, extends in the inner hole of the first pipe 11, and functions as a reinforcing material for preventing crushing of the first pipe 11.

A part of the rope 41 (a range from the front end of the first solenoid 43 to the front end of the leaf spring 42) is surrounded by the second solenoid 44.

The second coil 44 has a base end fixed to the tip end of the first coil 43 and a tip end fixed to the tip end of the leaf spring 42 (slightly closer to the base end side than the fixed position of the tip end 41A of the cord 41).

The inner diameter of the second solenoid 44 is slightly larger than the diameter of the rope 41, and the rope 41 can move (slide) in the second solenoid 44.

The second spiral pipe 44 is preferably made of a metal material such as stainless steel, and its outer surface is covered with a non-conductive member.

A distal end portion 41A of the cord 41 is fixed to a distal end portion of the leaf spring 42, and a proximal end portion of a core wire 51 having a shape memory property is also fixed to a distal end side thereof. The core wire 51 extends along the inner hole of the third tube 33, and its front end portion is fixed to the chip electrode 32 as shown in fig. 10.

The core wire 51 stores the loop shape of the catheter distal end portion 30, and is easily deformed (for example, linearly deformed) by application of force, but returns to the loop shape after removal of the force.

The core wire 51 is made of a Ni — Ti alloy. The ratio of Ni to Ti in the Ni-Ti alloy is preferably 54: 46 to 57: 43. A preferred Ni-Ti alloy is nitinol (ニチノ - ル).

The deflecting mechanism of the catheter tip portion 30 functions as follows. That is, when the operator slides the knob 22 of the control handle 20 toward the proximal end side, the pulling rope 41 is moved toward the proximal end side by a piston mechanism, not shown, in the control handle 20, whereby the leaf spring 42 to which the distal end portion 41A of the pulling rope 41 is fixed is bent at the distal end portion thereof, and the distal end portion (second tube 12) of the catheter main body 10 including the leaf spring 42 is bent, and as a result, the catheter distal end portion 30 is biased. When the knob 22 is slid toward the distal end side and returned to the original position, the plate spring 42 is linearly formed, and the catheter distal end portion 30 is returned to the original direction. In addition, it goes without saying that the deflection mechanism of the electrode catheter of the present invention is not limited to this structure.

The plurality of ring electrodes 31 and the chip electrodes 32 are connected to leads 61, respectively. The lead wires 61 connected to the ring electrode 31 enter the inner hole of the third tube 33 from the small holes formed in the tube wall of the third tube 33, extend along the inner hole of the third tube 33, the inner hole of the second tube 12, the inner hole of the first tube 11, and the inner hole (not shown) of the control handle 20, and the proximal end portions of the lead wires 61 are electrically connected to a connector 62 provided at the proximal end of the control handle 20.

The lead wire 61 is disposed so as to be slightly movable in the inner hole of the catheter main body 10 (the second tube 12, the first tube 11), and thus even if the catheter distal end portion 30 is biased, they are not broken.

As shown in fig. 11, the electrode catheter 1 is connected to an electrocardiograph 64 via a cable 63 connected to the connector 62, and the potential measured by the electrode catheter 1 is displayed on a monitor 65 of the electrocardiograph 64.

The electrode catheter 1 of the present embodiment is inserted into a main artery or vein such as a femoral artery, and then advanced to a target site (for example, a pulmonary vein of a heart) in a blood vessel.

At this time, it is desirable that the electrode catheter 1 is advanced while the chip electrode 32 positioned at the front is rotated in the backward direction (the direction indicated by the arrow B in fig. 6).

After reaching the measurement site of the potential, as shown in fig. 8, the ring diameter of the catheter tip 30 is enlarged with the chip electrode 32 as a fulcrum, and the ring electrode 31 is brought into contact with or close to the inner wall of the measurement site. These operations are usually performed while monitoring an X-ray image, and the spherical chip electrode 32 can be easily recognized in the X-ray image, thereby making it possible to easily grasp the entire position, state, and the like of the catheter tip portion 30.

[ second embodiment ]

Fig. 12 is an explanatory view of an electrode catheter according to another embodiment of the present invention, as viewed from the front end side.

The same reference numerals are used for the same or corresponding components as in the first embodiment.

The electrode catheter 2 of the present embodiment has the following features: the catheter distal end portion 70 connected to the distal end side of the catheter main body 10 is not a perfect circle but an oval ring shape. The tip portion 70 of the catheter is an ellipse having a ring shape, and the ratio of the minor axis to the major axis is preferably 1: 1.1 to 1: 3, more preferably 1: 1.1 to 1: 2.

The electrode catheter 2 of the present embodiment includes a deflection mechanism of the catheter tip portion 70. This deflecting mechanism deflects the catheter tip portion 70 in the minor axis direction (the direction indicated by the arrow F in fig. 12) of the annular shape, that is, the elliptical shape.

As such a deflecting mechanism, the same mechanism as that of the first embodiment may be adopted, and another mechanism may be adopted.

In the case of measuring the potential inside the blood vessel by a plurality of ring-shaped electrodes attached to the distal end portion of the catheter, it is desirable to set the distance between the plurality of ring-shaped electrodes and the inner wall of the blood vessel to be constant in order to improve the accuracy of measuring the potential.

However, according to statistics, the cross-sectional shape of the pulmonary vein of a human body is not strictly perfect circle but is approximated to an ellipse. Therefore, when the ring shape of the distal end portion of the catheter is a perfect circle, the distance from the inner wall of the pulmonary vein is not necessarily required between the plurality of ring-shaped electrodes attached thereto.

Accordingly, by setting the ring shape of the catheter distal end portion 70 to an elliptical shape, the catheter distal end portion 70 is more suitable for the inner wall of the pulmonary vein, and the distance from the inner wall of the pulmonary vein to the ring-shaped electrode 31 is substantially constant without being different between the ring-shaped electrodes 31, so that the accuracy of measuring the potential can be improved as compared with a perfect circular ring.

Further, since the electrode catheter 2 of the present embodiment includes the deflecting mechanism for deflecting the catheter tip portion 70 in the minor axis direction of the ellipse, when the electrode catheter 2 is operated while monitoring the X-ray image, the elliptical shape of the catheter tip portion 70 can be recognized in the X-ray image, the deflection direction (minor axis direction of the ellipse) can be grasped in advance, and the operation can be performed in accordance with the deflection direction, and therefore, the operation of guiding the catheter tip portion 70 to the target site is facilitated.

The electrode catheter of the present invention can be suitably applied to diagnosis of cardiac diseases, but is not limited thereto, and can also be applied to treatment of cardiac diseases, for example, when cauterizing an abnormal electrically active site.

Claims (9)

1. An electrode catheter, comprising:

a catheter body having at least one internal bore;

a control handle attached to a proximal end side of the catheter main body;

a catheter tip portion connected to the tip end side of the tip portion of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and formed in a circular ring shape,

a plurality of ring-shaped electrodes are mounted on the outer periphery of the catheter tip portion, and a spherical chip electrode is mounted on the tip end of the catheter tip portion,

the diameter of the spherical chip electrode is larger than the outer diameter of the tip portion of the catheter.

2. The electrode catheter according to claim 1, wherein a deflection mechanism of the catheter tip portion is provided.

3. An electrode catheter, comprising:

a catheter body having at least one internal bore;

a control handle attached to a proximal end side of the catheter main body;

a catheter tip portion connected to a tip end side of the tip portion of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and forming an elliptical ring shape;

a plurality of ring-shaped electrodes attached to an outer periphery of a distal end portion of the catheter;

a spherical chip electrode is attached to the tip of the catheter,

the diameter of the spherical chip electrode is larger than the outer diameter of the tip portion of the catheter.

4. An electrode catheter, comprising:

a catheter body having at least one internal bore;

a control handle attached to a proximal end side of the catheter main body;

a catheter tip portion connected to a tip end side of the tip portion of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and formed in a circular ring shape;

a plurality of ring-shaped electrodes attached to an outer periphery of a distal end portion of the catheter;

a deflecting mechanism for deflecting the distal end portion of the catheter main body,

the center of a circle in the shape of a ring of the catheter tip portion is separated from a plane including the direction in which the tip portion of the catheter main body is bent,

a spherical chip electrode is attached to the tip of the catheter,

the diameter of the spherical chip electrode is larger than the outer diameter of the tip portion of the catheter.

5. The electrode catheter of claim 4,

the catheter tip portion is formed into a circular ring extending in a clockwise direction from the tip portion of the catheter main body when the catheter tip portion is viewed from the front in a state in which the tip portion of the catheter main body is bent, and the tip portion of the catheter main body extends away to the right side from the center of a circle in the shape of a ring of the catheter tip portion.

6. The electrode catheter of claim 4,

the catheter tip portion is formed into a circular ring extending counterclockwise from the tip portion of the catheter main body when the catheter tip portion is viewed from the front in a state in which the tip portion of the catheter main body is bent, and the tip portion of the catheter main body extends away to the left side from the center of a circle in the shape of a ring of the catheter tip portion.

7. An electrode catheter, comprising:

a catheter body having at least one internal bore;

a control handle attached to a proximal end side of the catheter main body;

a catheter tip portion connected to a tip end side of the tip portion of the catheter main body, having an inner hole communicating with at least one of the inner holes of the catheter main body, and forming a spiral loop;

a plurality of ring-shaped electrodes attached to an outer periphery of a distal end portion of the catheter;

a deflecting mechanism for deflecting the distal end portion of the catheter main body,

the central axis of the spiral loop of the catheter tip portion is separated from a plane including the direction in which the tip portion of the catheter main body is bent,

a spherical chip electrode is attached to the tip of the catheter,

the diameter of the spherical chip electrode is larger than the outer diameter of the tip portion of the catheter.

8. The electrode catheter of claim 7,

the catheter tip portion is formed into a spiral loop extending in a clockwise direction from the tip portion of the catheter main body when the catheter tip portion is viewed from the front in a state in which the tip portion of the catheter main body is bent, and the tip portion of the catheter main body extends away to the right side from the central axis of the spiral loop.

9. The electrode catheter of claim 7,

the catheter tip portion is formed into a spiral loop extending counterclockwise from the tip portion of the catheter main body when the catheter tip portion is viewed from the front in a state in which the tip portion of the catheter main body is bent, and the tip portion of the catheter main body extends away to the left side from the central axis of the spiral loop.