HK1188917B - Electrode catheters - Google Patents

Description

Electrode catheter

Technical Field

The present invention relates to an electrode catheter, and more particularly, to an electrode catheter in which an electrode is attached to a distal end of a catheter and a mechanism for pouring a liquid such as physiological saline into the electrode is provided.

Background

An ablation catheter including a perfusion mechanism for cooling a distal end electrode that has reached a high temperature during cauterization is used as an electrode catheter.

As a conventional catheter including a perfusion mechanism, a catheter of a type in which a physiological saline solution supplied through a catheter shaft into a tip electrode is ejected from a plurality of openings formed in a surface of the tip electrode has been proposed (for example, see patent documents 1 and 2).

However, the conventionally known catheter in which the opening for irrigation is formed on the surface of the distal end electrode has the following problems (1) to (4).

(1) If an opening is provided on the surface of the front electrode, a sharp edge is inevitably formed at an opening edge or the like. When the distal electrode formed with such a sharp edge is used for cauterization, the current density at the sharp edge portion is extremely high, and an abnormal temperature rise occurs at the sharp edge portion, which may cause rapid thrombus formation.

(2) Even if the physiological saline is ejected from the opening formed on the surface of the tip electrode, sufficient priming (covering the surface with liquid) cannot be performed with respect to the surface of the tip electrode. In particular, in the catheters described in patent documents 1 and 2, in which the physiological saline is injected in the direction perpendicular to the axis of the distal end electrode, the physiological saline cannot be sufficiently brought into contact with the surface of the distal end electrode.

(3) Since a plurality of openings are formed on the electrode surface, the surface area of the tip electrode cannot be sufficiently secured, and effective cauterization treatment cannot be performed.

(4) A temperature sensor is generally provided inside a distal electrode constituting an ablation catheter, and cauterization treatment is performed while monitoring and controlling the temperature of the distal electrode and surrounding tissues.

However, the catheters described in patent documents 1 and 2 have a problem that the distal electrode is cooled more than necessary by the physiological saline supplied from the inside (flow path) of the distal electrode, and accurate temperature monitoring and control during the cauterization treatment cannot be performed by the temperature sensor provided inside the distal electrode. In order to solve such a problem, a technique is proposed in which a pouring member made of a heat insulating material is provided between a tip electrode provided with a temperature sensor and a catheter shaft, and the tip electrode is prevented from being cooled more than necessary by physiological saline (see patent document 3).

As a deflecting mechanism for performing a tip deflecting operation of the catheter, a plate spring is often used.

The plate spring is disposed along the central axis of the catheter shaft at a flexible portion at the front end of the catheter shaft. By using a plate spring as the deflecting means, sufficient torsional rigidity is imparted to the distal end flexible portion, and the operability of the catheter as a distal end deflecting operation and the planarity in the direction of deflection of the distal end portion of the shaft are improved. Patent document 4 listed below describes a catheter including a perfusion mechanism that uses a plate spring (center post) as a deflecting mechanism.

Prior art documents

Patent document

Patent document 1: japanese patent No. 2562861

Patent document 2: japanese patent laid-open publication No. 2006 and 239414

Patent document 3: japanese Kokai publication Hei-2009-537243

Patent document 4: japanese laid-open patent publication No. 2010-63886

Disclosure of Invention

However, in the electrode catheter including the perfusion mechanism, when a plate spring is used as the deflection mechanism, the inner lumen serving as a flow path for a liquid such as a physiological saline cannot be formed along the central axis of the catheter shaft, and must be formed eccentrically from the central axis.

However, when the lumen serving as a flow path for the liquid is formed eccentrically from the central axis of the catheter shaft, the diameter of the lumen cannot be sufficiently increased, and therefore, the liquid amount necessary for cooling the tip electrode or the like cannot be sufficiently secured. In addition, the risk of liquid leakage from the flow path formed eccentrically from the central shaft is increased. Further, when the catheter shaft is bent, the flow path that is eccentric from the center axis is more likely to be crushed.

The present invention has been made in view of the above circumstances.

An object of the present invention is to provide an electrode catheter equipped with a perfusion mechanism, which has excellent operability as a catheter capable of tip deflection operation and excellent planarity in the direction of deflection of a tip flexible portion, can perfuse a sufficient amount of liquid onto the surface of a tip electrode, and has a low risk of liquid leakage, clogging of a flow path, and the like.

It is another object of the present invention to provide an electrode catheter capable of uniformly perfusing liquid from a lumen eccentrically formed at a flexible portion of a catheter shaft in a circumferential direction with respect to a surface of a tip electrode.

(1) The electrode catheter of the present invention is characterized by comprising a catheter shaft having a distal end flexible portion and formed with an inner cavity serving as a fluid flow path, a plate spring disposed along a central axis of the catheter shaft at the distal end flexible portion of the catheter shaft, an insulating potting member connected to a distal end side of the catheter shaft, and a distal end electrode connected to a distal end side of the insulating potting member,

a plurality of pouring openings for pouring the liquid supplied from the catheter shaft to the surface of the tip electrode are arranged at equal angular intervals along the outer periphery of the insulating pouring member,

at least 2 lumens (hereinafter, also referred to as "distal end side flow passage forming lumens") forming a liquid flow passage are formed eccentrically from the central axis in the catheter shaft at the distal end flexible portion, and 1 central lumen forming a liquid flow passage is formed along the central axis in the non-flexible portion of the catheter shaft located on the proximal end side of the distal end flexible portion,

a flow path branching member is disposed on the catheter shaft so as to communicate between a central lumen serving as a liquid flow path in the non-flexible portion and a distal end side flow path forming lumen in the distal end flexible portion.

(2) In the electrode catheter of the present invention, it is preferable that the 2 distal-side flow paths forming the lumens in the distal-end flexible portion of the catheter shaft are formed so as to face each other with the central axis therebetween.

According to the electrode catheter having the above-described configuration, by disposing the flow path branching member that connects the central lumen serving as the liquid flow path in the non-flexible portion and each of the (at least) 2 distal side flow path forming lumens serving as the liquid flow paths in the distal end flexible portion, the liquid flowing through the central lumen can be branched by the flow path branching member for each of the distal side flow path forming lumens, and can be supplied to the irrigation member.

In the electrode catheter of the present invention, the distal end side flow passage forming lumen in the distal end flexible portion is formed eccentrically from the central axis of the catheter shaft, and therefore, the plate spring can be disposed in the distal end flexible portion along the central axis.

The electrode catheter of the present invention in which the plate spring is disposed as the deflecting mechanism provides sufficient torsional rigidity to the distal end flexible portion of the catheter shaft, and therefore is an electrode catheter excellent in operability as a catheter capable of being operated with distal end deflection and planarity in the direction of deflection of the distal end flexible portion, as compared with a conventional catheter in which a plate spring cannot be disposed (for example, the electrode catheter described in patent document 3 described above in which a lumen serving as a liquid flow path is formed along the central axis of the shaft over the entire region of the catheter shaft).

Further, since the central lumen serving as the liquid flow path is formed along the central axis in the non-flexible portion of the catheter shaft, a larger flow rate (perfusion amount) can be secured as compared with a conventional catheter (for example, the electrode catheter described in patent document 2 or patent document 4) in which the lumen serving as the liquid flow path is formed eccentrically over the entire region of the catheter shaft.

Therefore, according to the electrode catheter having the above-described configuration, a sufficient amount of liquid necessary for cooling or the like can be poured onto the surface of the distal electrode.

Further, by forming the liquid flow path in the central lumen in the inflexible part of the catheter shaft, the risk of liquid leakage, clogging of the flow path at the time of bending, and the like can be reduced as compared with a conventional catheter in which a lumen to become the liquid flow path is eccentrically formed over the entire region of the catheter shaft.

(3) In the electrode catheter of the above (2), preferably, the distal end flexible portion is constituted by a distal end side multi-lumen tube in which the plate spring is arranged and a plurality of lumens including 2 lumens serving as liquid flow paths are formed,

the non-flexible portion is formed by inserting a rear-end multi-lumen hose having the central lumen and a plurality of sub-lumens formed therearound into a disc hose having the non-flexible portion non-flexible,

the flow path branching member is disposed between the front-end-side multi-lumen hose and the rear-end-side multi-lumen hose,

an opening corresponding to the opening of the lumen of the distal-side multi-lumen hose is formed in the distal end surface of the flow path branching member, and an opening corresponding to the opening of the lumen of the rear-side multi-lumen hose is formed in the rear end surface of the flow path branching member.

Here, "an opening corresponding to the opening of the lumen" includes an opening of the inner bore that is disposed and formed so that the lumen and the inner bore (flow path or insertion path) of the flow path branching member can communicate with each other, in addition to an opening of the same shape as the opening of the lumen that is disposed so as to face the opening of the lumen.

According to the electrode catheter having such a configuration, each of the plurality of lumens formed in the distal-end-side multi-lumen tube constituting the distal-end flexible portion and each of the plurality of lumens (the central lumen and the sub-lumen) formed in the rear-end-side multi-lumen tube constituting the non-flexible portion can be communicated with each other via the flow path branching member.

(4) In the electrode conduit according to the above (3), preferably, the flow path branching member is formed with a rear end side reduced diameter portion into which the disk tube is inserted.

According to the electrode conduit having such a configuration, the flow path branching member can function as a stopper for the disk hose.

(5) In the electrode catheter of the present invention according to the above (3) or (4), the flow path branching member and the distal-side multilumen hose and the rear-side multilumen hose are preferably connected to each other via a joint hose.

According to the electrode catheter having such a configuration, it is possible to provide an electrode catheter in which the connection between the flow path branching member and the distal-side multi-lumen tube and the connection between the flow path branching member and the rear-side multi-lumen tube are ensured, and it is possible to prevent leakage of liquid at the contact portion between the rear end surface of the distal-side multi-lumen tube (the opening surface of the distal-side flow path forming lumen) and the distal end surface of the flow path branching member, and leakage of liquid at the contact portion between the rear end surface of the flow path branching member and the distal end surface of the rear-side multi-lumen tube (the opening surface of the central lumen) (the accompanying intrusion of liquid into another lumen formed on the shaft).

(6) In the electrode catheter of the present invention, it is preferable that at least 2 eccentric flow paths each communicating with each of lumens serving as a liquid flow path in the flexible portion at the distal end of the catheter shaft are formed in the insulating potting member,

A space communicating with the eccentric flow path, that is, a liquid retention space having no partition wall in the circumferential direction for uniformly distributing the liquid from the eccentric flow path in the circumferential direction of the insulating potting member,

A plurality of branch flow paths which are communicated with the retention space, extend towards the front end direction while inclining towards the outside, and reach each of the plurality of pouring openings.

According to the electrode catheter having such a configuration, since the opening for irrigation is formed in the insulating irrigation member, it is not necessary to form the opening in the distal electrode, and since there is no sharp edge accompanying the formation of the opening, an abnormal temperature rise does not occur in a part of the distal electrode at the time of cauterization, and therefore, the formation of thrombus is suppressed. In addition, since it is not necessary to form an opening in the distal electrode, a sufficient surface area can be secured, and effective cauterization treatment can be performed.

Further, since the liquid is poured from the insulating pouring member against the surface of the tip electrode, a sufficient amount of the liquid can be brought into contact with the surface of the tip electrode, and the liquid poured on the surface of the tip electrode flows along the surface of the tip electrode from the base end portion toward the tip end portion of the tip electrode, the surface of the tip electrode is excellent in cooling effect, and blood in the vicinity of the surface of the tip electrode is sufficiently stirred and diluted, thereby exhibiting an excellent effect of suppressing thrombus formation.

Further, since the plurality of pouring openings arranged at equal angular intervals along the outer periphery of the insulating pouring member are formed, the pouring can be performed over the entire region in the circumferential direction with respect to the surface of the tip electrode.

Further, by forming the eccentric flow path inside the insulating potting member, the liquid from the lumen of the catheter shaft (the eccentrically formed liquid flow path) can be made to flow toward the retention space.

Further, the insulating potting member is provided with a liquid retention space having no partition wall in the circumferential direction and a plurality of branch flow paths communicating with the retention space and extending toward the distal end while inclining outward, so that the liquid passing through the eccentric flow path and reaching the retention space is uniformly distributed in the circumferential direction in the retention space, and then is ejected (potted) from the potting openings through the plurality of branch flow paths extending toward the distal end, whereby the amount of liquid ejected between the plurality of potting openings arranged at equal angular intervals is not uniform, uniform ejection (potting) can be performed in the circumferential direction of the insulating potting member, and the surface of the distal end electrode can be uniformly potted over the entire region in the circumferential direction.

Furthermore, since the branch flow path formed inside the insulating potting member is formed to be inclined outward (outward in the radial direction of the insulating potting member), the potting opening (opening of the branch flow path) can be arranged outward, and thus potting can be performed even on the surface of a tip electrode having a large size to some extent (for example, a tip electrode having a diameter equal to or larger than the diameter of the catheter shaft).

Effects of the invention

According to the electrode catheter of the present invention, the operability as a catheter capable of tip deflection operation and the planarity in the direction of deflection of the tip flexible portion are excellent, a sufficient amount of liquid can be poured onto the surface of the tip electrode, and the risk of liquid leakage, clogging of a flow path, and the like is low.

According to the electrode catheter of the present invention, it is possible to uniformly perfuse the liquid from the lumen eccentrically formed at the flexible portion at the leading end of the catheter shaft in the circumferential direction with respect to the surface of the leading end electrode.

Drawings

Fig. 1 is a front view of an ablation catheter relating to an embodiment of the electrode catheter of the present invention.

Fig. 2 is a longitudinal sectional view of the main portion of the ablation catheter shown in fig. 1 (the main portion including the boundary of the front end flexible portion and the non-flexible portion).

Fig. 3 is a cross-sectional view of a main portion of the ablation catheter shown in fig. 1 (III-III cross-sectional view of fig. 2 (fig. 7)).

Fig. 4 is a cross-sectional view (fig. 2 (fig. 7) IV-IV sectional view) of a main portion of the ablation catheter shown in fig. 1.

Fig. 5 is a cross-sectional view (V-V cross-sectional view of fig. 2 (fig. 7)) of a main portion of the ablation catheter shown in fig. 1.

Fig. 6 is a cross-sectional view (VI-VI cross-sectional view of fig. 2 (fig. 7)) of a main portion of the ablation catheter shown in fig. 1.

Fig. 7 is a longitudinal sectional view (VII-VII sectional view of fig. 6) of the main part of the ablation catheter shown in fig. 1.

Fig. 8 is a perspective view showing a flow path branching member constituting the ablation catheter shown in fig. 1.

Fig. 9 is a perspective view showing a flow path branching member constituting the ablation catheter shown in fig. 1.

Fig. 10 is a perspective view of a main portion of the ablation catheter shown in fig. 1.

Fig. 11 is a perspective view of the main portion of the ablation catheter shown in fig. 1.

Fig. 12 is a perspective view of a main portion of the ablation catheter shown in fig. 1.

Fig. 13 is a perspective view of the main portion of the ablation catheter shown in fig. 1.

Fig. 14 is a longitudinal cross-sectional view of the forward end portion of the ablation catheter shown in fig. 1.

Fig. 15 is a cross-sectional view (C-C cross-sectional view of fig. 14 (fig. 19)) of the leading end portion of the ablation catheter shown in fig. 1.

Fig. 16 is a cross-sectional view (fig. 14 (fig. 19) B-B cross-sectional view) of the leading end portion of the ablation catheter shown in fig. 1.

Fig. 17 is a cross-sectional view of the leading end portion of the ablation catheter shown in fig. 1 (D-D cross-sectional view of fig. 14 (fig. 19)).

Fig. 18 is a cross-sectional view (a-a cross-sectional view of fig. 14 (fig. 19)) of the leading end portion of the ablation catheter shown in fig. 1.

Fig. 19 is a longitudinal cross-sectional view (cross-sectional F-F view of fig. 15) of the forward end portion of the ablation catheter shown in fig. 1.

Fig. 20 is a perspective view showing an irrigation member constituting the ablation catheter shown in fig. 1.

Fig. 21 is a perspective view showing an irrigation member constituting the ablation catheter shown in fig. 1.

Fig. 22 is a longitudinal sectional view (sectional G-G of fig. 16) of the front end portion of the ablation catheter shown in fig. 1.

Fig. 23 is a cross-sectional view (H-H cross-sectional view of fig. 22) of the leading end portion of the ablation catheter shown in fig. 1.

Fig. 24 is a cross-sectional view (I-I cross-sectional view of fig. 22) of the leading end portion of the ablation catheter shown in fig. 1.

Fig. 25 is a cross-sectional view (J-J cross-sectional view of fig. 22) of the leading end portion of the ablation catheter shown in fig. 1.

Detailed Description

An embodiment of an electrode catheter according to the present invention will be described below with reference to the drawings.

The electrode catheter shown in fig. 1 to 25 is an ablation catheter of the present invention for the treatment of arrhythmia of the heart.

The ablation catheter 100 of this embodiment includes: a catheter shaft 10 having a distal end flexible portion 10A and formed with an inner cavity to be a liquid flow path, an insulating potting member 20 connected to a distal end side of the catheter shaft 10, a distal end electrode 30 connected to a distal end side of the potting member 20, a ring electrode 40 attached to an outer peripheral surface of the distal end flexible portion 10A of the catheter shaft 10, pulling wires 61, 62 constituting a deflection mechanism for deflecting the distal end flexible portion 10A of the catheter shaft 10, a leaf spring 65 arranged along a central axis of the catheter shaft 10 and constituting the deflection mechanism together with the pulling wires 61, 62, a control handle 700 connected to a proximal end side of the catheter shaft 10, and an injection tube 800 for liquid;

on the pouring member 20, 8 pouring openings 25A for ejecting (pouring) the liquid supplied from the catheter shaft 10 to the surface of the tip electrode 30 are arranged at equal angular intervals (45 ° intervals) along the outer periphery of the pouring member 20;

on the catheter shaft 10, 2 front end side flow path forming lumens 11, 11 which become liquid flow paths are formed at a front end flexible portion 10A (front end side multi-lumen hose 101) thereof with a center axis in opposite directions (i.e., each eccentric from the center axis), 2 lumens 12, 12 which become insertion paths of pulling wires 61, 62 and 2 lumens 13, 13 which become insertion paths of pilot wires of the ring-shaped electrode 40 are formed, and on a non-flexible portion (rear end side multi-lumen hose 102) of the catheter shaft 10 which is located at a base end side of the front end flexible portion 10A, a central lumen 16 which becomes a liquid flow path is formed along the center axis, and 8 sub-lumens 171 to 178 are formed;

a flow path branching member 70 that connects the central lumen 16 serving as a liquid flow path in the non-flexible portion and the distal-end-side flow path forming lumens 11 and 11 serving as liquid flow paths in the distal-end flexible portion 10A to each other is disposed in the catheter shaft 10;

in the pouring member 20, there are formed 2 eccentric flow paths 23, 23 communicating with the flow path forming lumens 11, 11 on the tip side which become the liquid flow paths at the tip end flexible portion 10A of the catheter shaft 10, spaces communicating with the eccentric flow paths 23, that is, 8 branched flow paths 25 communicating with the holding space 24 of the liquid having no partition wall in the circumferential direction and extending in the tip end direction while inclining outward and reaching 8 pouring openings 25A so that the liquid from the eccentric flow paths 23, 23 is uniformly distributed in the circumferential direction of the pouring member 20, and a liquid guide groove 26 continuing to each of the 8 branched flow paths 25 and extending from each of the pouring openings 25A in the tip end portion of the pouring member 20;

a guide groove 36 for the liquid formed on the surface of the proximal end portion of the distal end electrode 30 and continuous with each of the guide grooves 26 of the pouring member 20;

the pouring member 20 is configured by fitting a first part 21 and a second part 22, the first part 21 having a front end side concave portion 21A capable of fitting with the cylindrical portion 33 of the front end electrode 30 formed therein and a concave portion 21B formed therein on the rear end side, and 8 branch flow paths 25 formed therein, the second part 22 having a front end side small diameter portion 221 capable of fitting with the rear end side concave portion 21B of the first part 21 and 2 eccentric flow paths 23, 23 formed therein;

by adjusting the depth (d) of the rear end side recess 21B of the first member 21₂₁) Formed to be longer than the length (d) of the front end side small diameter part 221 of the second member 22₂₂) A remaining space 24 (a space defined by the bottom surface (rear end surface) 21B of the rear end side recess 21B of the first part 21 and the inner peripheral surface and the front end surface 22a of the front end side small diameter portion 221 of the second part 22) is formed deeply in the fitting portion between the first part 21 and the second part 22.

As shown in fig. 1, an ablation catheter 100 includes: a catheter shaft 10 having a flexible portion 10A at the tip, an infusion member 20, a tip electrode 30, a ring electrode 40, a control handle 700, and a liquid injection tube 800.

The injection tube 800 shown in fig. 1 is connected to the catheter shaft 10 through the inside of the control handle 700, and liquid is supplied to the lumen (the central lumen 16 and the distal-side flow path forming lumens 11 and 11) of the catheter shaft 10 through the injection tube 800.

Here, the "liquid" may be, for example, a physiological saline solution.

The control handle 700 shown in fig. 1 is connected to the proximal end side of the catheter shaft 10, and includes a rotating plate 705 for performing a tip deflecting operation of the catheter.

The catheter shaft 10 constituting the ablation catheter 100 is a member having a front end flexible portion 10A.

Here, the "distal end flexible portion" refers to a distal end portion of the catheter shaft that can be flexed (bent) by pulling the wires for the distal end deflection operation (pulling wires 61, 62).

As shown in fig. 2, 6 and 7, the distal end flexible portion 10A of the catheter shaft 10 is composed of a distal end side multilumen hose 101 in which a leaf spring 65 is disposed and a plurality of lumens including the distal end side flow passage forming lumens 11 and 11 are formed, and a sheath member 103 covering the distal end side multilumen hose.

As shown in fig. 6 and 7, distal end side flow path forming lumens 11 and 11 serving as liquid flow paths are formed in the distal end flexible portion 10A of the catheter shaft 10 so as to face each other with the central axis of the catheter shaft 10 interposed therebetween.

As shown in fig. 6, the distal end flexible portion 10A is formed with 2 inner cavities 12 and 12 serving as insertion passages for the pull wires 61 and 62, inner cavities 13 and 13 serving as insertion passages for the lead wire 40L of the ring electrode 40, an inner cavity 14 serving as insertion passage for the lead wire 30L of the distal end electrode 30, and an inner cavity 15 serving as insertion passage for the lead wire 35L of the temperature sensor (thermocouple). As shown in fig. 6, in the present embodiment, 3 lead wires 40L are inserted into 1 of the lumens 13 and 13.

The catheter shaft 10 constituting the ablation catheter 100 has a non-flexible portion on the proximal end side of the distal end flexible portion 10A.

Here, the "non-flexible portion" refers to a portion that cannot be bent (bent) even if the wire for tip deflection operation is pulled.

As shown in fig. 2, 4 and 7, the inflexible part of the catheter shaft 10 is composed of a rear-end multi-lumen hose 102 in which a central lumen 16 and 8 sub-lumens 171 to 178 formed around the central lumen 16 are formed, a disc hose 80 in which the rear-end multi-lumen hose 102 is inserted, and a sheath member 103 covering the rear-end multi-lumen hose.

The disc hose 80 fitted inside the catheter shaft 10 is formed by winding a wire having a flat or circular cross section into a coil shape, and receives a reaction force of a pulling force acting on the pulling wire 61 or the pulling wire 62. Accordingly, when a pulling force is applied to the pulling wire 61 or the pulling wire 62, the portion (non-flexible portion) of the catheter shaft 10 to which the disc hose 80 is attached can be suppressed from being bent.

As shown in fig. 4 and 7, a central lumen 16 serving as a liquid flow path is formed along the central axis in the non-flexible portion of the catheter shaft 10.

As shown in fig. 4, 8 sub-cavities 171 to 178 including sub-cavities 171 and 175 serving as insertion passages for the pull wires 61 and 62, a sub-cavity 176 serving as an insertion passage for the lead wire 40L of the ring electrode 40, a sub-cavity 172 serving as an insertion passage for the lead wire 30L of the tip electrode 30, and a sub-cavity 173 serving as an insertion passage for the lead wire 35L of the temperature sensor (thermocouple) are formed in the non-flexible portion.

As shown in fig. 2 and 4 to 6, pulling wires 61, 62 for bending (performing a tip deflecting operation) the tip flexible portion 10A are disposed in the catheter shaft 10 (the lumens 12, 12 in the tip flexible portion 10A, the insertion passages 71, 72 in the flow path branching member 70 described later, and the sub-lumens 171, 175 in the non-flexible portion). The rear end portions of the pulling wires 61 and 62 are respectively coupled to a rotating plate 705 of the control handle 700 (see fig. 1). On the other hand, the leading end portions of the pulling wires 61 and 62 are fixed to the outer peripheral surface (the accommodating groove 226) of the pouring member 20 (the second component 22).

For example, when the rotating plate 705 is rotated in the a1 direction shown in fig. 1, the pulling wire 61 is pulled and the distal end flexible portion 10A of the catheter shaft 10 is deflected in the arrow a direction, and when the rotating plate 705 is rotated in the B1 direction shown in fig. 1, the pulling wire 62 is pulled and the distal end flexible portion 10A of the catheter shaft 10 is deflected in the arrow B direction.

As shown in fig. 6, in the distal end flexible portion 10A of the catheter shaft 10, a plate spring 65 is disposed along the central axis of the catheter shaft 10 on a plane perpendicular to the arrangement direction of the pulling wires 61, 62 (the bending direction of the distal end flexible portion 10A).

By disposing the plate spring 65 in the distal end flexible portion 10A, it is possible to secure anisotropy (planarity) in the bending direction of the distal end flexible portion 10A, and to impart sufficient torsional rigidity to the distal end flexible portion 10A, thereby improving operability at the time of the distal end deflecting operation.

The outer diameter of the catheter shaft 10 is preferably 1.0 to 3.0mm, more preferably 1.6 to 2.7mm, and in a preferable example, 2.36 mm.

The length of the catheter shaft 10 is preferably 600 to 1500mm, more preferably 900 to 1200 mm.

The catheter shaft 10 is provided with a flow path branching member 70 that communicates between a central lumen 16 serving as a liquid flow path in an inflexible part (a rear-end-side multi-lumen hose 102) and front-end-side flow path forming lumens 11 and 11 serving as liquid flow paths in a front-end flexible part 10A (a front-end-side multi-lumen hose 101).

The flow path branching member 70 is made of, for example, a molded body of an insulating resin or an insulating ceramic, and preferably a molded body obtained by a ceramic injection molding method (CIM).

As shown in fig. 2, 7, and 10, the flow path branching member 70 is disposed between the distal-end-side multi-lumen hose 101 and the rear-end-side multi-lumen hose 102.

The distal end surface 70A of the flow path branching member 70 abuts against the rear end surface of the distal-end-side multi-lumen hose 101. Further, the rear end side reduced diameter portion 76 of the flow path branching member 70 is inserted into the disc hose 80, and the rear end surface 70B of the flow path branching member 70 abuts against the front end surface of the rear end side multi-lumen hose 102. By inserting the rear end side reduced diameter portion 76 of the flow path branching member 70 into the disc tube 80, the flow path branching member 70 functions as a stopper for the disc tube 80 (the disc tube 80 is prevented from moving toward the distal end side by the flow path branching member 70).

As shown in fig. 2, 3, 5, and 7 to 9, an insertion passage 71 for the pulling wire 61, an insertion passage 72 for the pulling wire 62, a branching formation flow passage 73 for the liquid, an insertion passage 74 for the pilot wire 30L of the tip electrode 30 and the pilot wire 35L of the temperature sensor, and an insertion passage 75 for the pilot wire 40L of the ring electrode 40 are formed inside the flow path branching member 70. Here, the "branch-formed flow path" refers to a flow path (i.e., a flow path including a branch portion) in which 1 flow path is branched into a plurality of (2) branch flow paths.

In addition, an opening 73B (opening before branching) for branching the flow path 73 is formed in the rear end surface 70B of the flow path branching member 70 shown in fig. 3 and 8, and an opening 71B of the insertion path 71, an opening 72B of the insertion path 72, an opening 74B of the insertion path 74, and an opening 75B of the insertion path 75 are formed. These openings formed in the rear end surface 70B of the flow path branching member 70 correspond to the openings of the lumens formed in the front end surface of the rear end side multi-lumen hose 102 shown in fig. 4.

That is, the opening 73B of the branch forming flow path 73 formed in the rear end surface 70B corresponds to the opening of the central lumen 16 (liquid flow path) formed in the front end surface of the rear end-side multi-lumen hose 102, the openings 71B, 72B of the insertion paths 71, 72 correspond to the openings of the sub-lumens 171, 175 (insertion paths for the pull wires 61, 62), the opening 74B of the insertion path 74 corresponds to the openings of the sub-lumens 172 to 174 (insertion paths for the pilot wire 30L of the front end electrode 30 and the pilot wire 35L of the temperature sensor), and the opening 75B of the insertion path 75 corresponds to the opening of the sub-lumen 176 (insertion path for the pilot wire 40L of the ring-shaped electrode 40).

On the other hand, in the distal end surface 70A of the flow path branching member 70 shown in fig. 5 and 9, openings 731A and 732A for branching the forming flow path 73 are formed, and an opening 71A of the insertion path 71, an opening 72A of the insertion path 72, an opening 74A of the insertion path 74, and an opening 75A of the insertion path 75 are formed. These openings formed in the distal end surface 70A of the flow path branching member 70 correspond to the openings of the lumens formed in the rear end surface of the distal-end-side multi-lumen hose 101 shown in fig. 6.

That is, the openings 731A, 732A of the branch forming channel 73 formed in the distal end surface 70A correspond to the openings of the distal end side channel forming lumens 11, 11 formed in the rear end surface of the distal end side multilumen hose 101, the openings 71A, 72A of the insertion channels 71, 72 correspond to the openings of the lumens 12, 12 (insertion channels for the pulling wires 61, 62), the opening 74A of the insertion channel 74 corresponds to the openings of the lumen 14 (insertion channel for the pilot wire 30L of the distal end electrode 30) and the lumen 15 (insertion channel for the pilot wire 35L of the temperature sensor), and the opening 75A of the insertion channel 75 corresponds to the opening of the lumen 13 (insertion channel for the pilot wire 40L of the ring-shaped electrode 40).

With this configuration, each of the lumens (the distal-side flow passage forming lumens 11, the lumens 12, the lumen 13, the lumen 14, and the lumen 15) formed in the distal-side multi-lumen hose 101 constituting the distal-end flexible portion 10A and each of the lumens (the central lumen 16 and the sub-lumens 171 to 178) formed in the rear-side multi-lumen hose constituting the non-flexible portion can be communicated with each other through the flow path branching member 70.

As shown in fig. 3, 4, 7, 10, and 11, the branch forming flow path 73 (the rear end portion where the opening 73B is located) of the flow path branching member 70 and the central lumen 16 of the rear-end-side multi-lumen hose 102 communicate with each other via the joint hose 52.

Accordingly, the connection between the flow path branching member 70 and the rear-end-side multi-lumen hose 102 can be ensured, and liquid leakage at the contact portion between the rear end surface 70B (the surface on which the opening 73B is formed) of the flow path branching member 70 and the front end surface (the opening surface of the central lumen 16) of the rear-end-side multi-lumen hose 102 can be prevented.

As shown in fig. 5, 6, 7, 12, and 13, the branch forming channel 73 of the channel branching member 70 (the distal end portion where the openings 731A and 732A are located) and the distal end side channel forming lumens 11 and 11 of the distal end side multilumen hose 101 communicate with each other via the joint hoses 51 and 51.

Accordingly, the connection between the flow path branching member 70 and the distal-side multilumen hose 101 can be ensured, and liquid leakage at the contact portion between the distal end surface 70A (the surface on which the opening 731A and the opening 732A are formed) of the flow path branching member 70 and the rear end surface (the surface on which the distal-side flow path forming lumens 11 and 11 are formed) of the distal-side multilumen hose 101 can be prevented.

As described above, the distal-end-side flow passage forming lumens 11 and 11 formed in the distal-end-side multilumen hose 101 and the central lumen 16 formed in the rear-end-side multilumen hose 102 are communicated with each other via the flow passage branching member 70, whereby the liquid flow passage in the distal-end flexible portion 10A can be formed eccentrically from the central axis of the catheter shaft 10, and the liquid flow passage in the non-flexible portion can be formed along the central axis of the catheter shaft 10.

As described above, the central lumen 16 (liquid flow path in the inflexible part) formed in the rear-end-side multi-lumen hose 102 and the distal-end-side flow path forming lumens 11 and 11 (liquid flow path in the distal-end flexible part 10A) formed in the distal-end-side multi-lumen hose 101 are communicated with each other by the flow path branching member 70, whereby the liquid flowing through the central lumen 16 can be branched into each of the distal-end-side flow path forming lumens 11 and 11 by the flow path branching member 70 and supplied to the pouring member 20. Further, the liquid flow path in the distal end flexible portion 10A can be formed eccentrically from the center axis of the catheter shaft 10, and the liquid flow path in the non-flexible portion can be formed along the center axis of the catheter shaft 10.

Accordingly, the plate spring 65 can be disposed along the center axis at the distal end flexible portion 10A, and the distal end flexible portion 10A of the catheter shaft 10 can be given sufficient torsional rigidity, and compared with a conventional catheter in which a plate spring cannot be disposed, excellent operability and flatness in the bending direction can be found, and a sufficient flow rate (injection amount) can be secured by the central lumen 16 serving as a liquid flow path in the non-flexible portion.

In the ablation catheter 100, the ejection (irrigation) of the liquid to the surface of the leading electrode 30 is performed by the irrigation member 20 located on the rear end side of the leading electrode 30.

Fig. 20 and 21 are perspective views showing the shape of the irrigation member 20 constituting the ablation catheter 100.

As shown in fig. 14 and 19 to 22, the pouring member 20 is configured by fitting a first part 21 and a second part 22.

The second component 22 constituting the pouring member 20 is formed of a molded body in which a straight trunk portion 223 and a tip-side small diameter portion 221 having an outer diameter smaller than that of the straight trunk portion 223 are integrally formed.

In fig. 20 and 21, the front end small diameter portion 221 of the second component 22 is not shown in the drawings since it is fitted inside the first component 21 (the rear end concave portion 21B).

The outer diameter of the straight trunk portion 223 of the second member 22 is preferably 0.80 to 2.80mm, more preferably 1.80 to 2.12mm, and preferably 1.96 mm.

The outer diameter of the distal small-diameter portion 221 of the second member 22 is preferably 0.60 to 2.60mm, more preferably 0.40 to 1.70mm, and preferably 1.45 mm.

As shown in fig. 16, 17, 19 and 21, the second member 22 has a central through hole 224 formed along the central axis thereof, and eccentric flow paths 23 and 23 extending parallel to the central axis are formed on both sides of the central through hole 224. The central through hole 224 and the eccentric flow paths 23 and 23 are through holes reaching from the front end surface 22a of the second component 22 (the front end side small diameter portion 221) to the rear end surface 22b of the second component 22 (the straight body portion 223).

As shown in fig. 19, each of the openings of the eccentric flow paths 23, 23 in the rear end surface 22B of the second part 22 (section B-B of fig. 14 shown in fig. 16) is opposed to each of the openings of the front end side flow path forming cavities 11, 11 in the front end surface of the catheter shaft 10 (section C-C of fig. 14 shown in fig. 15).

The flow path forming lumens 11 and 11 on the tip side of the catheter shaft 10 and the eccentric flow paths 23 and 23 of the pouring member 20 (second component 22) communicate with each other through joint hoses 51 and 51.

Accordingly, the connection between the catheter shaft 10 and the pouring member 20 can be secured, and the leakage of the liquid at the contact portion between the tip end surface of the catheter shaft 10 (the opening surface of the tip side flow path forming lumens 11 and 11) and the rear end surface 22b of the rear end surface of the pouring member 20 (the opening surface of the eccentric flow paths 23 and 23) can be prevented, and the liquid can be prevented from entering the inside of the shaft.

As shown in fig. 19, the cross-sectional shapes of the eccentric flow paths 23, 23 through which the second component 22 (the straight trunk portion 223 and the tip-side small diameter portion 221) passes are changed from a circular shape to a substantially semicircular shape immediately before reaching the inside of the tip-side small diameter portion 221 from the inside of the straight trunk portion 223 (a step portion indicated by 231 in fig. 19). Therefore, although the opening shape of the eccentric flow paths 23, 23 in the rear end surface 22B of the second member 22 (the section B-B of fig. 14 shown in fig. 16) is circular, the opening shape of the eccentric flow paths 23, 23 in the front end surface 22a of the second member 22 (the section D-D of fig. 14 shown in fig. 17) is substantially semicircular.

By changing the cross-sectional shape of the eccentric flow paths 23, 23 in this manner, the thickness of the molding material (for example, a thickness of 60 μm or more) defining the eccentric flow paths 23, 23 at the tip-side small-diameter portion 221 can be ensured.

As shown in fig. 14, 20, and 21, receiving grooves 226 and 226 for receiving and fixing the distal end portions of the pulling wires 61 and 62 are formed in the outer peripheral surface of the second component 22 (straight body portion 223).

As shown in fig. 20 to 22 and 25, a receiving groove 225 is formed in the outer peripheral surface of the second component 22 (straight body portion 223) to receive the first lead wire 40L of the ring electrode 40 (first and second ring electrodes with the tip end thereof).

As shown in fig. 22, the storage groove 225 includes, from the front end to the rear end, a shallow groove portion 225a, an inclined portion 225b, and a deep groove portion 225 c.

Here, the width of the storage groove 225 is preferably 0.15 to 0.35mm, and more preferably 0.26 mm.

The depth of the shallow groove portion 225a of the housing groove 225 is preferably 0.10 to 0.20mm, and more preferably 0.12 mm.

The depth of the deep groove portion 225c of the receiving groove 225 is preferably 0.15 to 0.65mm, and preferably 0.50 mm.

The first part 21 constituting the pouring member 20 is formed of a molded body in which a straight trunk portion 213, a large diameter portion 212 having an outer diameter larger than that of the straight trunk portion 213, and a reduced diameter portion 211 having a diameter reduced toward the distal end are integrally formed.

The outer diameter of the straight trunk portion 213 of the first part 21 is substantially the same as the outer diameter of the straight trunk portion 223 of the second part 22, and the outer diameter of the large-diameter portion 212 is substantially the same as the outer diameter of the catheter shaft 10. The minimum outer diameter of the reduced diameter portion 211 of the first part 21 is substantially the same as the outer diameter of the neck portion 32 of the tip electrode 30.

As shown in fig. 14, 19, and 22, a tip-side concave portion 21A that can be fitted to the rear end portion (cylindrical portion 33) of the tip electrode 30 is formed on the tip side of the first component 21. Further, a rear end side recess 21B capable of being fitted to the front end side small diameter portion 221 of the second part 22 is formed on the rear end side of the first part 21.

Here, the depth of the rear end side recess 21B of the first member 21 (indicated by d in fig. 19)₂₁Shown) is formed longer than the length (indicated by d in fig. 19) of the distal end side small diameter portion 221 of the second member 22₂₂Represented) is deep.

As shown in fig. 19 and 20, in the first part 21 (reduced diameter portion 211), 8 irrigation openings 25A for ejecting (irrigating) the liquid supplied from the catheter shaft 10 to the surface of the tip electrode 30 are arranged at equal angular intervals (45 ° intervals) along the outer periphery of the irrigation member 20.

Further, inside the first member 21, 8 branch flow paths 25 (through holes) are formed which extend from the bottom surface (rear end surface) 21B of the rear end side concave portion 21B to the front end direction while inclining outward and reach the pouring openings 25A.

As shown in fig. 18, the openings of the branch flow paths 25 in the bottom surface (rear end surface) 21B of the rear end side concave portion 21B are also arranged at equal angular intervals (45 ° intervals) in the circumferential direction of the pouring member 20.

Each of the 8 branch flow paths 25 is formed to be inclined outward with respect to the axial direction of the pouring member 20 (outward in the radial direction of the pouring member 20).

Accordingly, even a surface of the tip electrode having a certain large size can be sufficiently filled with the solution.

Here, the inclination angle of the branch flow path 25 is preferably 3 to 45 °, more preferably 5 to 13 °, and preferably 7 ° as a suitable example.

Further, at the tip end portion (reduced diameter portion 211) of the first member 21, a liquid guide groove 26 is formed which is continuous with each of the 8 branch flow paths 25 and extends from each of the pouring openings 25A in the tip end direction.

In addition, although 8 branch flow paths 25, pouring openings 25A, and liquid guide grooves 26 are provided in the pouring member 20 (first component 21) at 45 ° intervals along the outer periphery of the pouring member 20, only a part of them is visible in fig. 19 showing a vertical cross section.

As shown in fig. 14, 18, 19, and 22, the first member 21 has a center through hole 214 formed along the center axis of the first member 21, and the center through hole 214 extends from the bottom surface (rear end surface) 21B of the rear-end recess 21B to the bottom surface (front end surface 21A) of the front-end recess 21A.

The center through hole 214 of the first component 21 and the center through hole 224 of the second component 22 form a center through hole of the pouring member 20.

As shown in fig. 14, 16 to 19, and 22 to 25, the central tube 54 is inserted into the central through hole (214, 224) of the pouring member 20. The pilot line 30L of the distal end electrode 30 and the pilot line 35L of the temperature sensor are inserted into the center tube 54.

As shown in fig. 20 to 24, 4 receiving grooves 215 capable of receiving the lead wires 40L of the ring electrodes 40 (the first ring electrode from the front end) are disposed at equal angular intervals (90 ° intervals) along the outer periphery of the straight trunk portion 213 on the outer peripheral surface of the first component 21 (the straight trunk portion 213).

Here, the width of the receiving groove 215 is preferably 0.12 to 0.50mm, and more preferably 0.34 mm.

The depth of the storage groove 215 is preferably 0.10 to 0.20mm, and more preferably 0.12 mm.

Of the 4 receiving grooves 215 formed in the outer peripheral surface of the first component 21 (the straight body portion 213), 1 is arranged on the same straight line as the receiving groove 225 formed in the outer peripheral surface of the second component 22 (the straight body portion 223), and the pilot line 40L of the ring-shaped electrode 40 is received in the receiving groove 215 and the receiving groove 225 of the second component 22.

As shown in fig. 22, the lead wire 40L of the first ring electrode 40 from the distal end is guided to the opening of the lumen 13 of the catheter shaft 10 through the receiving groove 215 and the receiving groove 225 (the shallow groove portion 225a, the inclined portion 225b, and the deep groove portion 225 c), enters the lumen 13 through the opening, passes through the lumen 13 of the catheter shaft 10 and the inside of the control handle 70, and is connected to a connector (not shown) connected to the inside of the control handle 70 or the proximal end side thereof. The first lead wire 40L of the second ring electrode 40 from the distal end is guided to the opening of the lumen 13 of the catheter shaft 10 through the receiving groove 225 (shallow groove/deep groove portion 225 c).

By forming the storage groove (the storage groove 215 in the first part 21 and the storage groove 225 in the second part 22) of the lead wire 40L on the outer peripheral surface of the potting member 20, the ring-shaped electrode 40 can be attached to the outer peripheral surface (region) of the catheter shaft 10 in which the potting member is located.

Accordingly, the distance (for example, about 2 mm) between the distal end electrode 30 and the first ring electrode 40 counted from the distal end can be shortened, and a desired potential can be measured between these electrodes.

The first member 21 and the second member 22 constituting the potting member 20 are formed of a molded body of an insulating resin or an insulating ceramic.

The first component 21 and the second component 22 are preferably formed of a molded body obtained by Ceramic Injection Molding (CIM).

According to the ceramic injection molding method, even a fine shape (for example, a fine shape having a wall thickness of about 60 μm) which cannot be formed by injection molding with a resin can be formed, and therefore, the potting member 20 having the above-described shape and size can be reliably molded.

The ceramic molded body obtained by the ceramic injection molding method has suitably low thermal conductivity as a constituent material of the potting member.

In addition, the ceramic molded body produced by the ceramic injection molding method is excellent in insulation, and even if a sharp edge is formed on the pouring member 20 made of the molded body, there is no case where a high temperature is generated by concentrating the current on the sharp edge portion when the ablation catheter 100 is used (cauterization).

As a suitable ceramic material constituting the potting member 20, zirconia is preferably used from the viewpoint of excellent moldability and biocompatibility.

The pouring member 20 is configured by fitting a rear end side recess 21B formed in the first component 21 and a front end side small diameter portion 221 of the second component 22.

In the fitting portion of the pouring member 20, a bottom surface (rear end surface) 21B of the rear end side recess 21B of the first component 21 and a front end surface 22a of the second component 22 are separated by d₂₁-d₂₂A jacket space is defined between the inner peripheral surface of the rear end side concave portion 21B and the outer peripheral surface of the central tube 54, and the jacket space serves as a liquid retention space 24.

The retention space 24 formed in this manner is a space for causing the liquids from the eccentric flow paths 23, 23 to merge and to be uniformly distributed in the circumferential direction of the pouring member 20. Since there is no partition wall in the circumferential direction in the storage space 24, the liquid flowing into the storage space 24 can be made to flow freely in the circumferential direction.

Here, the length (d) of the retention space 24 is₂₁-d₂₂) Superior foodPreferably 0.15 to 0.65mm, and more preferably 0.30 mm.

The pouring member 20 configured as described above has 2 eccentric flow paths 23, 23 formed inside the second part 21 so as to communicate with the flow path forming lumens 11, 11 on the tip side of the catheter shaft 10 serving as a liquid flow path, and spaces communicating with the eccentric flow paths 23, that is, so that the liquid from the eccentric flow paths 23, 23 is uniformly distributed in the circumferential direction of the pouring member 20, the liquid retention space 24 formed in the fitting portion between the first member 21 and the second member 22 and having no partition in the circumferential direction communicates with the retention space 24, and extends in the front end direction while inclining outward, and is formed in the interior of the first member so as to reach each of the pouring openings 25A, and is continuous with each of the 8 branch flow paths 25, and a liquid guide groove 26 formed in the distal end portion (the reduced diameter portion 211 of the first member) so as to extend from each of the pouring openings 25A in the distal end direction.

As shown in fig. 19, the straight trunk portion 213 and the second part 22 (the distal small diameter portion 221 and the straight trunk portion 223) of the first part 21 constituting the pouring member 20 are inserted (fitted) into the distal recess of the catheter shaft 10, and the eccentric flow paths 23 and 23 of the pouring member 20 communicate with the distal flow path forming lumens 11 and 11 of the catheter shaft via the joint hoses 51 and 51, whereby the pouring member 20 is connected to the distal end side of the catheter shaft 10.

Accordingly, only the reduced diameter portion 211 and the large diameter portion 212 of the first component 21 are represented as the external shape of the pouring member 20.

On the other hand, the tip electrode 30 is connected to the tip side of the pouring member 20 by fitting the cylindrical portion 33 of the tip electrode 30 in the tip side concave portion 21A of the pouring member 20 (first part 21).

The distal electrode 30, which is connected to the distal end side of the irrigation member 20 and constitutes the ablation catheter 100, has a hemispherical distal bulge portion 31, a neck portion 32, and a cylindrical portion 33.

The diameter of the distal end projection 31 of the distal end electrode 30 is preferably 1.0 to 3.3mm, more preferably 2.2 to 2.6mm, particularly preferably 2.3 to 2.5mm, and preferably 2.36 mm.

When the diameter of the distal end bulge 31 (the maximum diameter of the distal end electrode 30) is D1 and the tube diameter of the catheter shaft 10 is D2, the values of D1/D2 are preferably 1.0 or more, more preferably 1.0 to 1.5, and in a preferred example, 1.0 (D1/D2 is 2.36mm/2.36 mm).

When the value of D1/D2 is too small, it is difficult to perform effective cauterization treatment using a catheter having such a tip electrode.

On the other hand, when the value of D1/D2 is too large, it is difficult to pour a sufficient amount of liquid onto the surface of the tip electrode.

Further, the reason why a sufficient amount of liquid can be poured onto the surface of the distal end electrode 30 having a value of D1/D2 of 1.0 or more is that the branch flow path 25 of the pouring member 20 is inclined outward, so that the pouring opening 25A is positioned outward as compared with a case where the branch flow path is not inclined. At this point, it makes sense to clamp the pouring member 20.

Further, a liquid guide groove 36 continuous with each of the guide grooves 26 of the pouring member 20 is formed in the base end portion (neck portion 32) of the tip electrode 30.

By forming the guide groove 36, the liquid that has passed through the guide groove 26 formed in the pouring member 20 and reached the base end portion of the tip electrode 30 can be guided (guided) to the tip end portion of the tip electrode 30, whereby the liquid can be supplied to the entire surface of the tip electrode 30 including the tip bulging portion 31.

In addition, since the guide groove 36 formed in the distal end electrode 30 has a gentle R shape, an abnormal temperature rise does not occur in this portion even at the time of cauterization.

As described above, according to the ablation catheter 100 of the present embodiment, the channel branching member 70 is disposed so as to communicate between the central lumen 16 serving as the liquid channel in the non-flexible portion and the distal end side channel forming lumens 11 and 11 serving as the liquid channels in the distal end flexible portion 10A, whereby the liquid flowing through the central lumen 16 can be branched to the 2 distal end side channel forming lumens 11 and supplied to the irrigating member 20.

In the ablation catheter 100 of the present invention, the distal end side flow passage forming lumens 11 and 11 (the liquid flow passage in the distal end flexible portion 10A) in the distal end flexible portion 10A are formed eccentrically from the central axis of the catheter shaft 10, and therefore, the plate spring 65 can be arranged along the central axis in the distal end flexible portion 10A.

Since the ablation catheter 100 in which the leaf spring is disposed as the deflecting mechanism imparts sufficient torsional rigidity to the distal end flexible portion 10A of the catheter shaft 10, the catheter that can be operated with distal end deflection has superior operability and planarity in the direction of deflection of the distal end flexible portion, compared to a conventional catheter (a catheter in which a lumen that becomes a fluid flow path is formed along the central axis of the shaft over the entire region of the catheter shaft) in which the leaf spring cannot be disposed.

Further, since the central lumen 16 serving as a liquid flow path is formed along the central axis in the non-flexible portion of the catheter shaft 10, a flow rate (irrigation liquid amount) larger than that of a conventional catheter in which a lumen serving as a liquid flow path is eccentrically formed over the entire region of the catheter shaft can be secured, and a sufficient amount of liquid necessary for cooling or the like can be irrigated to the surface of the distal end electrode 30.

Further, by forming the liquid flow path by the central lumen 16 in the inflexible part of the catheter shaft 10, the risk of liquid leakage, flow path blockage at the time of bending, and the like can be reduced as compared with a conventional catheter in which the lumen serving as the liquid flow path is formed eccentrically from the central axis over the entire region of the catheter shaft.

Furthermore, since the irrigation opening 25A is formed in the insulating irrigation member 20 and there is no sharp edge on the conductive tip electrode 30, there is no abnormal temperature rise (high-temperature portion) in a part of the tip electrode 30 when the ablation catheter 100 is used (at the time of cauterization), and it is possible to suppress the blood from contacting such a high-temperature portion to cause thrombus. Furthermore, since it is not necessary to form an opening in the distal end electrode 30, a sufficient surface area can be secured for cauterization, and effective cauterization treatment can be performed.

Furthermore, according to the ablation catheter 100 of this embodiment, since the liquid is ejected (irrigated) from the 8 irrigation openings 25A disposed at the distal end portion of the irrigation member 20 against the surface of the distal end electrode 30, a sufficient amount of liquid can be brought into contact with the surface of the distal end electrode 30.

Further, the liquid ejected toward the surface of the leading end electrode 30 flows along the surface of the leading end electrode 30 from the base end portion (neck portion 32) toward the leading end portion (leading end bulging portion 31) of the leading end electrode 30.

Therefore, the ablation catheter 100 has an excellent cooling effect on the surface of the distal electrode 30 as compared with a conventionally known catheter in which an opening for irrigation is formed in the distal electrode, and exhibits a more excellent effect of suppressing thrombus formation by sufficiently stirring and diluting blood around the distal electrode 30.

In addition, since the 8 irrigation openings 25A are arranged at equal angular intervals (45 °) along the outer periphery of the irrigation member 20, the surface of the distal end electrode 30 can be irrigated over the entire circumferential region (360 °).

Furthermore, since the 2 distal end side flow path forming lumens 11, 11 serving as the liquid flow paths, the 2 lumens 12, 12 serving as insertion paths for the pulling wires 61, 62, and the 2 lumens 13, 13 serving as insertion paths for the pilot wires of the ring electrode 40 are formed at eccentric positions in the distal end flexible portion 10A of the catheter shaft 10, the plate spring 65 that cannot be disposed in the conventional infusion catheter having an infusion member can be disposed along the central axis in the distal end flexible portion 10A of the catheter shaft 10.

Further, the ablation catheter 100 in which the leaf spring 65 is arranged is excellent in operability by giving sufficient torsional rigidity to the distal end flexible portion 10A of the catheter shaft 10.

Furthermore, since the liquid passing through the eccentric flow paths 23, 23 and reaching the holding space 24 is coordinated to flow in the holding space 24 by the 8 branch flow paths 25 which are formed in the inside of the pouring member 20 and have no partition in the circumferential direction, communicate with the holding space, extend in the distal direction while inclining outward, and reach each of the pouring openings 25A, and are uniformly distributed in the circumferential direction, and then are ejected (poured) from the pouring openings 25A by passing through each of the 8 branch flow paths 25, there is no influence of circumferential inconsistency in the amount of liquid supplied from the catheter shaft 10 to the pouring member 20 (circumferential inconsistency due to the eccentric formation of the 2 distal side flow path forming lumens 11, 11 which become the liquid flow paths by the plate spring 65 arranged at the distal end flexible portion 10A), the amount of liquid injected between the 8 irrigation openings 25A arranged at equal angular intervals (45 °) can be uniformly injected (irrigated) in the circumferential direction of the irrigation member 20 without causing inconsistency, and the surface of the distal end electrode 30 can be uniformly irrigated over the entire circumferential region (360 °).

Furthermore, the pouring member 20 is configured by fitting the rear-end side concave portion 21B (rear-end shape of the first component) formed in the first component 21 and the front-end side small diameter portion 221 (front-end shape of the second component) of the second component 22, and the front-end electrode 30 can be connected to the front end side of the pouring member 20 by fitting the cylindrical portion 33 (rear-end shape of the front-end electrode) of the front-end electrode 30 and the front-end side concave portion 21A (front-end shape of the first component) of the first component 21.

By forming the pouring member 20 of two parts in this manner, the problem of undercut due to the shape of the retention space 24 can be avoided, and the pouring member 20 having the eccentric flow paths 23 and 23, the retention space 24, and the 8 branch flow paths 25 formed therein can be obtained by molding.

Further, since each of the branch flow paths 25 formed inside the pouring member 20 (first part 21) is formed to be inclined outward, even with respect to the surface of the tip electrode (tip electrode 30 having a value of 1.0 of D1/D2) having a somewhat large size, pouring can be sufficiently performed.

Further, by forming the liquid guide grooves 26 extending in the distal end direction continuously from each of the branch flow paths 25 at the distal end portion of the pouring member 20 (first component 21), the liquid ejected from the pouring opening 25A can be reliably guided (guided) toward the distal end electrode 30.

Further, by forming the guide grooves 36 for the liquid continuous with each of the guide grooves 26 of the pouring member 20 on the surface of the proximal end portion of the distal end electrode 30, the liquid that has passed through the guide grooves 26 formed in the pouring member 20 and reached the proximal end portion of the distal end electrode 30 can be guided to the distal end portion of the distal end electrode 30, and thus, the liquid can be supplied to the entire surface of the distal end electrode 30.

While one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made.

For example, the number of the branch flow paths (pouring openings) in the pouring member may be other than 8, and may be appropriately selected from the range of 4 to 12, for example.

The number of lumens in the catheter shaft which serve as liquid flow paths (the number of eccentric flow paths in the pouring member) may be 1 or 3 or more instead of 2. However, the present invention is effective when a catheter shaft having a small number of lumens to be liquid flow paths is used.

In addition, the inner structure of the catheter shaft is not particularly limited, and the lumen that becomes the liquid flow path may be formed eccentrically in the flexible portion at the tip.

The shape of the tip electrode is not particularly limited, and may be a shell shape or the like.

Description of the symbols

100: an ablation catheter; 10: a catheter shaft; 101: a multi-lumen hose at a front end side; 102: a rear end side multi-lumen hose; 103: a skin member; 10A: a front end flexible portion; 11: the front end side flow path forms an inner cavity; 12: an inner cavity (insertion path for pulling the wire); 13: an inner cavity (insertion path of a pilot wire of the annular electrode); 14: an inner cavity (a passage for inserting a pilot wire of a front end electrode); 15: an inner cavity (a passage for inserting a pilot wire of the temperature sensor); 16: a central lumen; 171 to 178: a secondary lumen; 21: a first part; 211: a diameter reducing portion; 212: a large diameter portion; 213: a straight trunk; 214: a central through hole; 215: firstly, a wire accommodating groove; 21A: a front end side concave portion; 21 a: a bottom surface (front end surface) of the front end side recess 21A; 21B: a rear end side concave portion; 21 b: a bottom surface (rear end surface) of the rear end side recess 21B; 22: a second part; 221: a front end side small diameter part; 223: a straight trunk; 224: a central through hole; 225: firstly, a wire accommodating groove; 226: a receiving groove for receiving the front end of the pulling metal wire; 22 a: a front end surface of the front end side small diameter portion; 23: an eccentric flow path; 231: a height difference portion; 24: a liquid retention space; 25: a branch flow path; 25A: an opening for perfusion; 26: a guide groove for the liquid; 30: a front-end electrode; 30L: a lead wire of the front electrode; 31: a front end bulging section; 32: a neck portion; 33: a cylindrical portion; 35L: a pilot line of a temperature sensor; 36: a guide groove for the liquid; 40: a ring-shaped electrode; 40L: a pilot line of the ring-shaped electrode; 51: a joint hose; 54: a central hose; 61: pulling the metal wire; 62: pulling the metal wire; 65: a plate spring; 70: a flow path branching member; 71: an insertion path for pulling the metal wire; 72: an insertion path for pulling the metal wire; 73: a branched flow path for the liquid; 74: a lead wire of the front end electrode and a lead wire of the temperature sensor are inserted into the passage; 75: the insertion path of the first lead of the annular electrode; 76: a rear end side diameter reducing portion; 70A: a front end face; 71A: an opening of the insertion path; 72A: an opening of the insertion path; 731A: an opening of the branch flow path; 732A: an opening of the branch flow path; 74A: an opening of the insertion path; 75A: an opening of the insertion path; 70B: a rear end face; 71B: an opening of the insertion path; 72B: an opening of the insertion path; 73B: an opening of the branch flow path; 74B: an opening of the insertion path; 75B: an opening of the insertion path; 80: a disc hose; 700: a control handle; 705: a rotating plate; 800: a liquid injection pipe.

Claims (6)

1. An electrode catheter characterized by comprising a catheter shaft having a distal end flexible portion and formed with an inner cavity serving as a fluid flow path, a leaf spring disposed along a central axis of the catheter shaft at the distal end flexible portion of the catheter shaft, an insulating potting member connected to a distal end side of the catheter shaft, and a distal end electrode connected to a distal end side of the insulating potting member,

a plurality of pouring openings for pouring the liquid supplied from the catheter shaft to the surface of the tip electrode are arranged at equal angular intervals along the outer periphery of the insulating pouring member,

at least 2 lumens forming a liquid flow path are formed eccentrically from the central axis in the tip flexible portion of the catheter shaft, and 1 central lumen forming a liquid flow path is formed along the central axis in the non-flexible portion of the catheter shaft located on the proximal end side of the tip flexible portion,

a flow path branching member is disposed on the catheter shaft so as to communicate with each of a central lumen serving as a liquid flow path in the non-flexible portion and a lumen serving as a liquid flow path in the distal flexible portion.

2. The electrode catheter according to claim 1, wherein 2 lumens forming a fluid flow path in the flexible tip portion of the catheter shaft are formed so as to face each other with the central axis therebetween.

3. The electrode catheter according to claim 2, wherein the distal end flexible portion is constituted by a distal end side multi-lumen tube in which the plate spring is arranged and a plurality of lumens including 2 lumens serving as a liquid flow path are formed,

the non-flexible portion is formed by inserting a rear-end multi-lumen hose having the central lumen and a plurality of sub-lumens formed therearound into a disc hose having the non-flexible portion non-flexible,

the flow path branching member is disposed between the front-end-side multi-lumen hose and the rear-end-side multi-lumen hose,

an opening corresponding to the opening of the lumen of the distal-side multi-lumen hose is formed in the distal end surface of the flow path branching member, and an opening corresponding to the opening of the lumen of the rear-side multi-lumen hose is formed in the rear end surface of the flow path branching member.

4. The electrode catheter according to claim 3, wherein a rear end side reduced diameter portion into which the disk tube is inserted is formed in the flow path branching member.

5. The electrode catheter according to claim 3, wherein the flow path branching member and the distal-side multi-lumen hose and the rear-side multi-lumen hose are connected via joint hoses.

6. The electrode catheter according to any one of claims 1 to 5, wherein at least 2 eccentric flow paths, which communicate with each of lumens that become liquid flow paths in the flexible portion at the distal end of the catheter shaft, are formed in the insulating potting member,

A space communicating with the eccentric flow path, that is, a liquid retention space having no partition wall in the circumferential direction for uniformly distributing the liquid from the eccentric flow path in the circumferential direction of the insulating potting member,

A plurality of branch flow paths which are communicated with the retention space, extend towards the front end direction while inclining towards the outside, and reach each of the plurality of pouring openings.