JP7762085B2 - Ablation catheter - Google Patents

Description

The present invention relates to an ablation catheter.

Ablation catheters are treatment devices that deliver high-frequency waves to the distal tip to cauterize lesions within the heart. Because of the risk of blood clots due to the temperature rise that occurs during ablation, ablation catheters with an irrigation function to cool the distal tip are now being used. Cooling the distal tip with irrigation can reduce the risk of blood clots, but there is still room for improvement in terms of cooling functionality.

The invention described in Patent Document 1 is a radiofrequency heating balloon catheter that heats tissue in contact with the balloon as uniformly as possible to provide thermal treatment to the affected area. This device heats the balloon by using radiofrequency waves to heat the fluid inside the balloon. It discloses that, to eliminate temperature unevenness inside the balloon, an electrode wire that heats the fluid inside the balloon is rotated. Furthermore, Patent Document 2 describes an invention called a conduction heating catheter that necrotizes and excises tissue by heating. It is provided with a fluid circulation device that circulates a heat transfer fluid through the heating device so as to rapidly supply sufficient heat to the fluid without contaminating the catheter's heating element. One such example is a fluid heating device equipped with an impeller rotated by a motor.

Japanese Patent Application Laid-Open No. 2003-102850 Special Publication No. 2001-515368

Patent Document 1 discloses rotating a heating element to equalize the temperature inside the balloon of a balloon catheter. When applied to the distal tip of an ablation catheter, the extremely narrow lumen of the distal tip makes it difficult to rotate the cooling element inside the distal tip. The catheter disclosed in Patent Document 2 requires an external output such as a motor for rotation, which necessitates the need for a new external output device specifically for ablation catheters. The present invention aims to solve these problems and provide a mechanism suitable for ablation catheters.

The ablation catheter of the present invention, which solves the above problems, has a liquid supply lumen inside the tube that serves as a liquid flow path, and a movable body that moves with the liquid flow is located in the distal portion of the tube. This allows for uniform cooling within the catheter, thereby preventing thrombus formation and complications. Specifically, the ablation catheter of the present invention is characterized by comprising a tube having a distal end and a proximal end, a liquid supply unit located on the proximal side of the tube, a liquid supply lumen located inside the tube that serves as a liquid flow path for liquid supplied from the liquid supply unit, an ablation electrode located in the distal portion of the tube, and a movable body located in the distal portion of the tube that moves with the flow of liquid supplied from the liquid supply unit.

It is preferable that the movable body be a rotating mechanism that rotates at a predetermined position in the distal portion of the tube due to the flow of liquid supplied from the liquid supply section.

It is preferable that the ablation electrode has an internal space, the liquid supply lumen is connected to the internal space of the ablation electrode, and the movable body is located somewhere between the liquid supply lumen and the internal space of the ablation electrode. More preferably, the movable body is located in the internal space of the ablation electrode. It is also preferable that the ablation electrode is a tip located at the distal end of the tube.

It is preferable that the ablation catheter further include a liquid return lumen disposed inside the tube, which serves as a flow path for returning the liquid supplied to the internal space of the ablation electrode to the proximal side of the tube.

It is also preferable that the ablation catheter have holes on the side or tip of the ablation electrode.

The rotation axis of the rotation mechanism may be perpendicular to the longitudinal direction of the tube. Alternatively, the rotation axis of the rotation mechanism may extend parallel to the longitudinal direction of the tube.

The rotating part of the rotation mechanism is preferably an impeller, water wheel, gear, or screw shape. The rotating part of the rotation mechanism preferably has a blade portion, and the blade portion preferably has a recess for receiving liquid. The blade portion is preferably arranged at an angle to the extension direction of the rotation axis of the rotating part.

The ablation catheter may have an inner tube disposed inside the liquid supply lumen. A high-frequency power source may also be disposed proximal to the tube, and a lead wire connecting the ablation electrode to the high-frequency power source may be disposed inside the inner tube.

The ablation catheter of the present invention provides a liquid supply lumen, which is a liquid flow path, inside the tube, and a movable body that moves with the flow of liquid is placed in the distal part of the tube. This allows the liquid flowing inside the tube to be agitated or disturbed by the movable body, or to generate an intentional water flow. This allows the ablation electrode located in the distal part of the tube to be uniformly cooled, suppressing the formation of thrombi.

1 shows a schematic diagram of an ablation catheter according to an embodiment of the present invention. 2 illustrates an example of a longitudinal cross-sectional view of the distal portion of the tube of the ablation catheter shown in FIG. 1. 3 shows a cross-sectional view perpendicular to the longitudinal direction of the distal portion of the tube shown in FIG. 2. 2 illustrates another example of a longitudinal cross-sectional view of the distal portion of the tube of the ablation catheter shown in FIG. 1. 2 illustrates another example of a longitudinal cross-sectional view of the distal portion of the tube of the ablation catheter shown in FIG. 1. 2 illustrates another example of a longitudinal cross-sectional view of the distal portion of the tube of the ablation catheter shown in FIG. 1.

The present invention will be described in detail below based on the following embodiments, but the present invention is not limited to these embodiments and can of course be implemented with appropriate modifications within the scope of the above and below-described intent, all of which are within the technical scope of the present invention. For convenience, hatching and component symbols may be omitted in the drawings. In such cases, please refer to the specification or other drawings. The dimensions of various components in the drawings may differ from their actual dimensions, as priority is given to aiding understanding of the features of the present invention.

An ablation catheter according to an embodiment of the present invention comprises a tube having a distal end and a proximal end, a liquid supply unit located on the proximal side of the tube, a liquid supply lumen located inside the tube and serving as a flow path for liquid supplied from the liquid supply unit, an ablation electrode located in the distal portion of the tube, and a movable body located in the distal portion of the tube that moves with the flow of liquid supplied from the liquid supply unit.

Figures 1 to 6 show examples of the configuration of an ablation catheter according to an embodiment of the present invention. Figure 1 shows a schematic diagram of the entire ablation catheter, Figures 2 and 4 to 6 show examples of the configuration of the distal portion of the tube of the ablation catheter shown in Figure 1, showing cross-sectional views along the longitudinal direction, and Figure 3 shows a cross-sectional view perpendicular to the longitudinal direction of the distal portion of the tube shown in Figure 2.

As shown in FIG. 1, the ablation catheter 1 comprises a tube 2 and an ablation electrode 4 disposed at the distal end of the tube 2. The tube 2 extends in the longitudinal direction, and a proximal side and a distal side are defined relative to the longitudinal direction. The proximal side refers to the direction toward the user, i.e., the operator, relative to the direction of extension of the tube 2, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. The proximal and distal sides of the ablation catheter 1 are also defined based on the longitudinal direction of the tube 2. The direction perpendicular to the longitudinal direction is referred to as the radial direction. The ablation catheter 1 can cauterize tissue, for example, a lesion within the heart, by passing high-frequency current through the ablation electrode 4. The high-frequency current is supplied to the ablation electrode 4 from a high-frequency power source 15 connected to the proximal side of the tube 2, for example, via a conductor.

The tube 2 is preferably made of resin. Resins that can be used for the tube 2 include polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, and fluorine-based resins (e.g., PTFE, PFA, ETFE). Among these, polyamide resins, polyimide resins, and fluorine-based resins are preferred, and nylon is particularly preferred from the standpoints of flexibility and electrical resistance. The outer diameter of the tube 2 can be selected appropriately depending on the therapeutic application, but is preferably approximately 1.5 mm to 3.0 mm.

The ablation electrode 4 is made of a metal. Examples of metals that can be used for the ablation electrode 4 include copper, gold, platinum, aluminum, iron, and alloys of these. Among these, platinum, platinum alloys (e.g., platinum iridium and platinum palladium), and stainless steel are preferred from the standpoint of electrical conductivity and heat transfer, with platinum iridium being particularly preferred.

The ablation electrode 4 may be provided as a tip (tip electrode) located at the distal end of the tube 2, or as a ring electrode located proximal to the tip. In the drawings, the ablation electrode 4 is provided as a tip 5. The ablation electrode 4 can be attached to the tube 2 by known joining means such as adhesive bonding, welding, or crimping.

The ablation electrode 4 is connected to the high-frequency power supply 15, for example, via a conductor, allowing the ablation electrode 4 to function as an electrode that cauterizes tissue. The conductor preferably connects the ablation electrode 4 to the high-frequency power supply 15 and is positioned inside the tube 2. Examples of materials that can be used for the conductor include iron wire, silver wire, stainless steel wire, copper wire, tungsten wire, nickel-titanium wire, and alloys thereof. The conductor preferably contains a conductive core material, which is coated with an insulating material. Examples of insulating materials that can be used include fluorine-based resins (e.g., PTFE, PFA, FEP, ETFE), polyolefin resins (e.g., polyethylene and polypropylene), and polyvinyl chloride resins.

The shape of the tip 5 of the ablation electrode 4 can be spherical, hemispherical, cylindrical, needle-like, cone-like, frustum-like, or a combination of these. To prevent damage to blood vessels or the inside of the heart, the distal end of the tip 5 preferably has a smooth shape, such as a hemispherical shape. The size of the tip 5 can be selected appropriately depending on the treatment application, but is preferably approximately 1.5 mm to 3.0 mm.

The ablation catheter 1 has a liquid supply unit 14 disposed proximal to the tube 2, and a liquid supply lumen 3, which is a flow path for liquid supplied from the liquid supply unit 14, provided inside the tube 2. The liquid supply lumen 3 extends longitudinally within the tube 2. By supplying liquid to the liquid supply lumen 3, the ablation catheter 1 can cool the ablation electrode 4, thereby suppressing the formation of thrombi in the body cavity due to a rise in the temperature of the ablation electrode 4.

The liquid supply unit 14 is used to send liquid sent from an external device or the like into the ablation catheter 1, specifically into the liquid supply lumen 3 of the tube 2, and is made of a material containing resin or metal. The liquid supply unit 14 may include a pump for sending liquid into the ablation catheter 1. A syringe, for example, may be used as the liquid supply unit 14. The liquid supply unit 14 may also include a cooling unit for cooling the liquid being supplied.

The liquid supply lumen 3, which serves as a flow path for the liquid supplied from the liquid supply unit 14, is disposed inside the tube 2. The tube 2 may have only one liquid supply lumen 3 or multiple liquid supply lumens 3.

Tube 2 may have either a single-lumen structure with one internal lumen, or a multi-lumen structure with multiple internal lumens. Alternatively, one lumen may split into multiple internal lumens. Tube 2 may also have a coaxial structure with multiple coaxial lumens.

If the tube 2 has a single lumen structure, the lumen of the tube 2 can be used as the liquid supply lumen 3. In this case, since there is no boundary with other lumens inside the tube 2, it is easy to expand and can have many functions.

When the tube 2 has a multi-lumen structure (including a coaxial structure), any of the lumens inside the tube 2 can be used as the liquid supply lumen 3. For example, the liquid supply lumen 3 may be a lumen of the tube 2, or a lumen of another tube placed inside the tube 2. When the tube 2 has a multi-lumen structure, expandability is reduced, but specific lumens can be given individual functions, making management easier. For example, it is possible to provide a lumen that serves as a liquid flow path and a lumen for placing a conductor connecting the ablation electrode 4 and the high-frequency power source 15.

The ablation catheter 1 is provided with a movable body 7 at the distal portion of the tube 2, which moves due to the flow of liquid supplied from the liquid supply unit 14. In the drawings, the movable body 7 is provided as a rotating mechanism that rotates due to the flow of liquid supplied from the liquid supply unit 14. By providing the movable body 7 at the distal portion of the tube 2, the movable body 7 can agitate the liquid flowing within the tube 2, disrupt the flow, or generate an intentional water flow. This allows the ablation electrode 4 to be uniformly cooled, effectively suppressing the formation of thrombi in the body cavity due to an increase in the temperature of the ablation electrode 4.

The movable body 7 is preferably capable of stirring the liquid flowing within the tube 2, disrupting the flow of the liquid, or generating an intentional water current (e.g., a swirling flow). The movable body 7 is disposed within the tube 2 in contact with the liquid supplied from the liquid supply unit 14, and is not particularly limited as long as it moves within the tube 2 due to the flow of the liquid, for example, by rotating or moving. The movable body 7 that moves within the tube 2 is preferably formed so that the movable body 7 remains within a predetermined range within the tube 2, for example, by widening a portion of the liquid flow path within the tube 2, and the movable body 7 is disposed in this widened portion. The movable body 7 that rotates within the tube 2 is arranged to rotate at a predetermined position within the tube 2.

The movable body 7 can be made of resin or metal. Examples of resins include polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polycarbonate resins, polyurethane resins, polyimide resins, and fluorine-based resins (e.g., PTFE, PFA, ETFE). Examples of metals include iron, copper, aluminum, gold, platinum, and alloys of these.

The movable body 7 is positioned in the distal portion of the tube 2. The distal portion of the tube 2 where the movable body 7 is positioned preferably ranges from a position 30 mm proximal to the proximal end of the ablation electrode 4 (or, if multiple ablation electrodes 4 are provided, from the proximal end of the most proximal ablation electrode 4) to the distal end of the tube 2, and more preferably ranges from a position 20 mm proximal to the proximal end of the ablation electrode 4 to the distal end of the tube 2. The movable body 7 is preferably positioned at any point within this range on the tube 2.

The ablation electrode 4 has an internal space, the liquid supply lumen 3 is connected to the internal space of the ablation electrode 4, and the movable body 7 is preferably located somewhere between the liquid supply lumen 3 and the internal space of the ablation electrode 4. When the movable body 7 is located in the liquid supply lumen 3, it is preferably located within 30 mm, and more preferably within 20 mm, proximal to the proximal end of the ablation electrode 4. By configuring the tube 2 in this manner, liquid supplied from the liquid supply unit 14 passes through the liquid supply lumen 3 and reaches the internal space of the ablation electrode 4, allowing the liquid to effectively cool the ablation electrode 4.

The ablation electrode 4 is preferably a distal tip 5 located at the distal end of the tube 2. That is, as the ablation electrode 4, the distal tip 5 is preferably cooled by liquid supplied from the liquid supply unit 14. In this case, the liquid supply lumen 3 extends from the liquid supply unit 14 to the distal tip 5, and the liquid supplied from the liquid supply unit 14 preferably reaches the internal space of the distal tip 5. By cooling the distal tip 5 with liquid supplied from the liquid supply unit 14, the formation of thrombi within the body cavity can be effectively suppressed. Furthermore, by cooling the distal tip 5, if a ring electrode is provided as the ablation electrode 4 proximal to the distal tip 5, the ring electrode can also be cooled.

The tip 5, which has an internal space, can be produced by methods such as pouring metal into a mold to form it, or by carving the inside of a block of metal.

In the above case, the movable body 7 is preferably positioned within the internal space of the distal tip 5 or within 30 mm proximal to the proximal end of the internal space of the distal tip 5, more preferably within 20 mm proximal to the internal space of the distal tip 5 or within 20 mm proximal to the proximal end of the internal space of the distal tip 5, and even more preferably positioned within the internal space of the distal tip 5. This allows the distal tip 5 to be cooled effectively.

The movable body 7 is preferably a rotation mechanism that rotates at a predetermined position in the distal portion of the tube 2 due to the flow of liquid supplied from the liquid supply unit 14. By providing a rotation mechanism as the movable body 7, the liquid flowing within the tube 2 is forcibly agitated by the rotation mechanism, allowing for more uniform cooling of the ablation electrode 4 located in the distal portion of the tube 2. The ablation catheter 1 is configured so that the rotation mechanism is rotated by the liquid supplied through the liquid supply lumen 3 and does not require a power source to rotate the rotation mechanism, allowing the tube 2 to be made thinner and more flexible. The flow rate of liquid flowing through the liquid supply lumen 3 within the thin tube 2 is limited, and it is preferable that the rotation mechanism be designed to rotate even with a small flow rate.

The rotation mechanism includes a rotating unit 8 and is rotatable around a rotation axis. The rotation axis is located at the rotation center of the rotation mechanism. The rotating unit 8 has blades 9 that can agitate the liquid flowing inside the tube 2. The blades 9 are preferably formed in the shape of plates extending radially from the rotation axis, and the plates may be formed in either a flat or curved shape. It is preferable that multiple blades 9 be provided on the rotating unit 8; for example, it is preferable that one rotating unit 8 be provided with 2 to 12 blades 9.

The rotating unit 8 may or may not have a shaft 10 at the position that forms the rotation axis. In the former case, the blades 9 are preferably provided so as to extend radially from the shaft 10. In the latter case, for example, it is preferable that the rotating unit 8 has a cylindrical portion, and the blades 9 are provided so as to extend inward (towards the rotation axis) from the inner surface of the cylindrical portion. Alternatively, the rotating unit 8 may have a shaft 10 and a cylindrical portion, and the blades 9 may be provided so as to connect the shaft 10 to the inner surface of the cylindrical portion.

The blades 9 may be arranged parallel to, perpendicular to, or at an angle to the extension direction of the rotation axis of the rotating unit 8. The arrangement of the blades 9 relative to the rotation axis is determined based on the extension direction of the cross-sectional shape of the blades 9 on the rotation axis side. It is preferable to appropriately set the arrangement of the blades 9 relative to the rotation axis based on the rotation direction of the rotating unit 8.

In one embodiment, the blades 9 are preferably arranged at a certain angle relative to the rotation axis. In other words, the blades 9 are preferably arranged diagonally relative to the extension direction of the rotation axis. By providing the blades 9 in this manner, the liquid flowing inside the tube 2 can be efficiently agitated. The blades 9 are preferably arranged at an angle of, for example, 30° to 75° relative to the extension direction of the rotation axis.

Specific forms or shapes of the rotating part 8 include an impeller, water wheel, gear, screw shape, etc. The blades 9 of the rotating part 8 preferably each have a recess to more easily receive liquid. The recess is preferably spoon-shaped. This makes it easier for the rotating mechanism to rotate with a small flow rate.

The rotating part 8 of the rotation mechanism can be made of resin or metal. For the resin or metal that makes up the rotating part 8, please refer to the explanation of the constituent materials of the movable body 7 above. Among them, examples of resins include synthetic resins such as polycarbonate, polyethylene, and silicone, and examples of metals include platinum alloys, stainless steel, and platinum-palladium.

The rotation mechanism is positioned somewhere between the liquid supply lumen 3 and the internal space of the ablation electrode 4. The rotation mechanism may be arranged so that its rotation axis is perpendicular to the longitudinal direction of the tube 2, so that its rotation axis extends parallel to the longitudinal direction of the tube 2, or so that its rotation axis extends obliquely relative to the longitudinal direction of the tube 2. Note that, because it is easy to install the rotating unit 8, which serves as the rotation mechanism, inside the tube 2, it is preferable that the rotation axis of the rotation mechanism extend perpendicular to or parallel to the longitudinal direction of the tube 2.

The rotating part 8 of the rotation mechanism may have its shaft 10 attached to the inner wall of the liquid supply lumen 3 or the inner wall of the ablation electrode 4, or a shaft support member supporting the shaft 10 may be disposed inside the liquid supply lumen 3 or the ablation electrode 4. If the rotating part 8 of the rotation mechanism has a cylindrical part and the blades 9 are formed to extend inward from the inner surface of the cylindrical part, the rotating part 8 may be disposed in an unfixed state inside the liquid supply lumen 3 or the ablation electrode 4. For example, an enlarged diameter part may be provided inside the liquid supply lumen 3 or the ablation electrode 4, and the rotating part 8 having a cylindrical part may be rotatably fitted into the enlarged diameter part.

The rotating part 8 of the rotation mechanism is preferably located within the internal space of the distal tip 5 or within 30 mm proximal to the proximal end of the internal space of the distal tip 5, more preferably within 20 mm proximal to the internal space of the distal tip 5 or within the proximal end of the internal space of the distal tip 5, and even more preferably located in the internal space of the distal tip 5. When the rotating part 8 is located in the internal space of the distal tip 5, it is preferably located in the internal space of the distal tip 5, near the distal end of the liquid supply lumen 3. By installing a liquid rotation mechanism such as a water wheel in such a location, a deliberate water flow can be generated, allowing for efficient liquid replacement in the distal tip 5. This allows the distal tip 5 to be uniformly cooled, thereby suppressing the occurrence of thrombus formation.

In one embodiment, as shown in FIG. 2, the ablation electrode 4 can have a hole 6 through which liquid supplied from the liquid supply unit 14 is discharged. In this case, the ablation catheter 1 is endowed with an irrigation function, and the liquid supplied from the liquid supply unit 14 cools the ablation electrode 4 and then is discharged from the hole 6 to the outside of the tube 2, thereby efficiently cooling the ablation electrode 4.

The holes 6 can be provided anywhere on the ablation electrode 4, but are preferably provided on the side or tip of the ablation electrode 4. In particular, it is preferable that the distal tip 5 of the ablation electrode 4 is cooled by liquid supplied from the liquid supply unit 14, and that the holes 6 be provided on the side or tip of the distal tip 5.

In the above configuration, as shown in Figures 2 and 3, it is preferable that the rotation axis of the rotation mechanism extend parallel to the longitudinal direction of the tube 2. This allows the liquid supplied to the inside of the ablation electrode 4 to be efficiently agitated by the rotation mechanism, allowing the ablation electrode 4 to be cooled more uniformly.

In another embodiment, as shown in FIG. 4, the ablation catheter 1 can further include a liquid return lumen 11 disposed inside the tube 2, which serves as a flow path for returning the liquid supplied to the internal space of the ablation electrode 4 to the proximal side of the tube 2. In this case, the ablation electrode 4 does not have a hole 6, and the tube 2 is a closed type with a closed distal portion. The liquid supplied to the liquid supply lumen 3 from the liquid supply unit 14 circulates in the distal portion of the tube 2, thereby uniformly cooling the internal space of the ablation electrode 4. In this case, the liquid supply unit 14 disposed on the proximal side of the tube 2 may include a recovery unit that recovers the liquid returned through the liquid return lumen 11, or a circulation unit that circulates the liquid between the liquid supply unit 14 and the distal portion of the tube 2.

In the above embodiment, as shown in Figure 4, it is preferable that the rotation axis of the rotation mechanism is perpendicular to the longitudinal direction of the tube 2. This allows the liquid supplied from the liquid supply lumen 3 to be smoothly returned to the liquid return lumen 11. In this case, it is preferable that the rotating unit 8 of the rotation mechanism is disposed in the internal space of the distal tip 5. Because the rotation axis is disposed in a direction perpendicular to the longitudinal direction of the tube 2, it is preferable that the rotating unit 8 be disposed within the distal tip 5 so that the rotation axis is parallel to the cross-sectional direction of the longitudinal axis of the tube 2. It is preferable that the rotating unit 8 be disposed near the distal end of the liquid supply lumen 3.

In the configuration shown in Figure 4, the tube 2 has a double lumen structure, one of which serves as the liquid supply lumen 3 and the other as the liquid return lumen 11. In the configuration shown in Figure 4, it is preferable that the inner diameter of the liquid supply lumen 3 be smaller than the inner diameter of the liquid return lumen 11, as this makes it easier to rotate the rotation mechanism with a small amount of liquid.

As shown in Figure 5, the tube 2 can have a coaxial structure, an inner tube 12 can be placed inside the tube 2, the lumen of the inner tube 12 can be used as the liquid supply lumen 3, and the space between the tube 2 and the inner tube 12 can be used as the liquid return lumen 11.

In the configuration shown in Figure 5, it is preferable to provide a rotation mechanism inside the inner tube 12 (i.e., the liquid supply lumen 3) or distal to it. The rotation axis of the rotation mechanism preferably extends parallel to the longitudinal direction of the tube 2, and when viewed from the distal side of the tube 2, the rotating part 8 is preferably formed to be radially smaller than the inner diameter of the tube 2, and more preferably smaller than the outer diameter of the inner tube 12. This allows the liquid supplied from the liquid supply lumen 3, which is the lumen of the inner tube 12, to be smoothly returned to the liquid return lumen 11, which is the space between the tube 2 and the inner tube 12.

Figure 6 shows an example in which an inner tube 13 is placed inside the liquid supply lumen 3 of the tube 2 in the configuration shown in Figure 4. That is, the tube 2 has a double lumen structure, with one of the lumens having a coaxial structure. A conductor, for example, connecting the ablation electrode 4 to the high-frequency power source 15 can be placed in the inner tube 13. This improves the insulation between the inside and outside of the inner tube 13. For example, this prevents electricity from flowing through the liquid supplied from the liquid supply unit 14, thereby improving the insulation of the catheter 1. In this case, the inner tube 13 is preferably made of an insulating or electrically resistant resin such as polyamide resin (e.g., nylon), fluorine-based resin, or polyimide resin. From the standpoint of insulation, it is more preferable that the inner tube 13 be made of polyimide.

Although not shown in the drawings, in the configuration shown in Figure 4, another tube can also be placed inside the liquid return lumen 11 of the tube 2. In the configuration shown in Figure 2, another tube can also be placed inside the liquid supply lumen 3. Furthermore, in the configuration shown in Figure 5, another tube can also be placed inside the liquid supply lumen 3 or inside the liquid return lumen 11.

1. Ablation catheter 2. Tube 3. Fluid supply lumen 4. Ablation electrode 5. Distal tip 6. Hole 7. Movable body 8. Rotating part 9. Blade part 10. Shaft part 11. Fluid return lumen 12. Inner tube 13. Inner tube 14. Fluid supply part 15. High frequency power supply

Claims (13)

a tube having a distal end and a proximal end;
a liquid supply disposed proximal to the tube;
a liquid supply lumen disposed inside the tube and serving as a flow path for liquid supplied from the liquid supply unit;
an ablation electrode disposed in a distal portion of the tube and supplied with a high-frequency current from a high-frequency power source ;
a movable body disposed in a distal portion of the tube and moved by the flow of liquid supplied from the liquid supply portion ;
The ablation electrode has an internal space and a hole on a side surface or a tip thereof,
the fluid supply lumen communicates with the interior space of the ablation electrode;
The movable body is an ablation catheter disposed in the internal space of the ablation electrode . a tube having a distal end and a proximal end;
a liquid supply disposed proximal to the tube;
a liquid supply lumen disposed inside the tube and serving as a flow path for liquid supplied from the liquid supply unit;
an ablation electrode disposed in a distal portion of the tube and supplied with a high-frequency current from a high-frequency power source ;
a movable body that is a rotation mechanism that is disposed in a distal portion of the tube and rotates by the flow of liquid supplied from the liquid supply portion ,
the ablation electrode has an interior space;
the fluid supply lumen communicates with the interior space of the ablation electrode;
the movable body is disposed at any location from the liquid supply lumen to the internal space of the ablation electrode,
An ablation catheter in which the rotation axis of the rotation mechanism is perpendicular to the longitudinal direction of the tube . The ablation catheter according to claim 2 , wherein the movable body is disposed in the internal space of the ablation electrode. The ablation catheter according to claim 2 or 3 , wherein the ablation electrode has a hole on a side surface or a tip. The ablation catheter according to claim 1 , wherein the movable body is a rotation mechanism that rotates due to the flow of liquid supplied from the liquid supply unit. The ablation catheter according to claim 5 , wherein the rotation axis of the rotation mechanism extends parallel to the longitudinal direction of the tube. The ablation catheter according to any one of claims 2 to 6 , wherein the rotating part of the rotation mechanism is in the shape of an impeller, a water wheel, a gear, or a screw. The ablation catheter according to any one of claims 2 to 7 , wherein the rotating part of the rotation mechanism has a blade part, and the blade part has a depression for receiving a liquid. The ablation catheter according to any one of claims 2 to 8 , wherein the rotating part of the rotation mechanism has blades, and the blades are disposed obliquely with respect to the extending direction of the rotation axis of the rotating part. The ablation catheter according to any one of claims 1 to 9 , wherein the ablation electrode is a tip disposed at the distal end of the tube. The ablation catheter according to any one of claims 1 to 10 , further comprising a liquid return lumen disposed inside the tube and serving as a flow path for returning the liquid supplied to the internal space of the ablation electrode to the proximal side of the tube. The ablation catheter according to any one of claims 1 to 11 , wherein an inner tube is disposed inside the liquid supply lumen. The high frequency power source is disposed proximal to the tube;
The ablation catheter according to claim 12 , wherein a conductor connecting the ablation electrode and the high-frequency power source is disposed inside the inner tube.