JP2022173169A - medical device - Google Patents

Abstract

To provide a medical device which comprises electrode parts combining adhesion to a lesioned part with suppression of deformation caused by a valve or an operator.SOLUTION: A medical device 10 comprises a long-sized shaft part 21 and each electrode part 40 which is disposed at the distal end of the shaft part 21, slender along the axis of the shaft part 21 and extensible radially. The electrode part 40 includes a first portion 41 including the distal end of the electrode part 40 and a second portion 42 including the proximal end of the electrode part 40 and disposed at the proximal end of the first portion 41, and has an insulated surface. The first portion 41 has a conductive part 43 including a surface conductive layer 55 exposed in the extending direction of the electrode part 40 and is formed to be more flexible than the second portion 42.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a medical device that is inserted into a living body and that treats living tissue by energizing it.

As a medical device, a device that performs treatment by irreversible electroporation (IRE) is known. Irreversible electroporation is attracting attention because it is non-thermal and can reduce damage to surrounding blood vessels and nerves. For example, there is known a medical device that uses irreversible electroporation to treat cancer that is difficult to remove by surgery.

A medical device that performs irreversible electroporation has a plurality of radially expandable electrodes along the circumferential direction, and allows electricity to flow between the electrodes while the electrodes are in close contact with living tissue. As such a medical device, for example, there is a device as described in Patent Document 1.

Japanese Patent No. 6013186

A medical device is inserted into a living body through a tubular body that has been inserted into the living body in advance. A valve body is provided at the inlet of the tubular body inserted into the living body to prevent blood from flowing out. If the electrodes of the medical device are made flexible, the adhesiveness to the lesion is improved, but they are easily deformed when passing through the valve body, which may lead to poor expansion of the electrodes. Also, when the operator holds the electrode part by hand and inserts it, the electrode part may be deformed.

On the other hand, if the electrode of the medical device is made hard, deformation when passing through the valve body or the like is suppressed, but adhesion at the lesion site is reduced. In particular, when the lesion has an irregular shape, it is difficult for the electrode to adhere to the living tissue. The electrode of the medical device of Patent Document 1 has a small width at the distal end and a proximal end, and a large width at the intermediate portion. Conceivable.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a medical device having an electrode portion that achieves both adhesion to a lesion site and suppression of deformation by a valve body or an operator. do.

A medical device according to the present invention that achieves the above objects includes an elongated shaft portion; an electrode portion disposed at a distal end portion of the shaft portion, elongated along the axis of the shaft portion and radially expandable; wherein the electrode section includes a first portion including a distal end portion of the electrode portion and a proximal end portion of the electrode portion, is disposed on the proximal side of the first portion, and has an insulated surface. and a second portion, wherein the first portion has a conductive portion including a surface conductive layer exposed in an extending direction of the electrode portion, and is formed more flexible than the second portion.

In the medical device configured as described above, the first portion of the electrode portion that contacts the lesion is flexible, and the other portions are hard. can be compatible. Further, by holding the second portion of the electrode portion by hand, it is possible to prevent the electrode portion from being damaged during insertion.

Further, the first portion has a tip insulating portion arranged at the tip portion of the electrode portion, and the conducting portion arranged on the base end side from the tip insulating portion, and the conducting portion is the If the second portion is formed more flexible than the conductive portion and the tip insulating portion is formed more flexible than the conductive portion, discontinuity of flexibility in the length direction can be alleviated.

Further, if the first portion is formed flexibly by being smaller in thickness than the second portion, the first portion can be easily formed flexibly by adjusting the thickness.

Further, if the first portion is made of a material that is more flexible than the second portion, the first portion can be easily formed flexibly by selecting the material. .

In addition, the electrode portion is formed by laminating a plurality of layers, and the first portion has fewer layers than the second portion, so that it can be formed flexibly. By doing so, the first portion can be easily and flexibly formed.

Further, if the first portion is formed flexibly by having notches in the width direction in at least part of the length direction of the electrode portion, the shape, size, number, etc. of the notches can be adjusted. , the first portion can be easily and flexibly formed.

Further, the shaft portion has an elongated outer tube and an inner tube that is inserted into the outer tube so as to protrude from the tip of the outer tube and is slidable in the axial direction with respect to the outer tube. The distal end portion of the electrode portion is fixed to the distal end portion of the inner tube, and the proximal end portion of the electrode portion is fixed to the distal end portion of the outer tube. By sliding the inner tube in the axial direction, the electrode portion having the flexible portion can be expanded and contracted.

Further, a balloon for expanding the electrode portion is provided at the distal end portion of the shaft portion, and at least a part of the first portion of the electrode portion is joined to the balloon. Since the first portion is joined to the balloon, the electrode portion does not interfere with expansion of the balloon.

Further, if the second portion does not come into contact with the inflated balloon, only the flexible region of the electrode portion is brought into contact with living tissue, thereby improving the adhesion of the electrode portion.

It is a front view showing an outline of a medical device in a 1st embodiment. 2 is an enlarged cross-sectional view of the vicinity of the distal end of the medical device; FIG. It is a top view of an electrode part. FIG. 4 is a cross-sectional view of the electrode section taken along a plane parallel to the length direction; 4 is an enlarged cross-sectional view of the vicinity of the distal end portion of the medical device with the electrode portion expanded. FIG. It is sectional drawing which cut|disconnected the electrode part of the 1st modification in the plane parallel to the length direction. It is sectional drawing which cut|disconnected the electrode part of the 2nd modification in the plane parallel to the length direction. It is sectional drawing which cut|disconnected the electrode part of the 3rd modification in the plane parallel to the length direction. FIG. 11 is a cross-sectional view of electrode portions of fourth to sixth modifications taken along a plane parallel to the length direction; FIG. 10 is an enlarged cross-sectional view of the vicinity of the distal end portion of the medical device in the second embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings may be exaggerated for convenience of explanation and may differ from the actual ratios. In addition, in this specification, the side of the medical device 10 that is inserted into a living body cavity is referred to as the "distal end" or "distal end side", and the hand side to be operated is referred to as the "proximal end" or "proximal end side".

The medical device 10 of the present embodiment is percutaneously inserted into a living body cavity, contacts a living tissue of a target site, applies an electric current, and performs irreversible electroporation. The medical device 10 can also be used for high-frequency ablation and electro-chemical therapy.

As shown in FIG. 1 , the medical device 10 has an electrode section 40 at the distal end of a long tubular shaft section 21 . The shaft portion 21 has an outer tube 30 and an inner tube 24 . The inner tube 24 is inserted through the outer tube 30 so as to protrude from the distal end of the outer tube 30 and is axially slidable relative to the outer tube 30 . The medical device 10 also has a balloon 22 . The medical device 10 has a connection line 33 for applying voltage to the electrode section 40 along the length direction. The connection line 33 is connected to the power supply section 12 provided outside the medical device 10 . The power supply unit 12 can apply voltage to the electrode unit 40 . At the tip of the outer tube 30, a tip member 31 for fixing the base end of the electrode part 40 is provided. At the tip of the inner tube 24, a tip fixing member 45 for fixing the tip of the electrode part 40 is provided. are provided respectively.

The balloon 22 is provided at the distal end of the inner tube 24 . A hub 23 is provided at the proximal end of the inner tube 24 .

As shown in FIG. 2, the inner tube 24 has a double tube structure in which an inner first tubular body 25 and an outer second tubular body 26 are concentrically arranged. A guide wire lumen 27 through which the guide wire 11 is inserted is formed in the hollow interior of the first tubular body 25 . An expansion lumen 28 is formed in the hollow interior of the second tubular body 26 and outside the first tubular body 25 to allow the fluid for expanding the balloon 22 to flow therethrough.

The first tubular body 25 protrudes further to the tip side than the tip of the second tubular body 26 . The balloon 22 has its proximal end fixed to the second tubular body 26 and its distal end fixed to the first tubular body 25 . This allows the interior of the balloon 22 to communicate with the expansion lumen 28 . Balloon 22 may be expanded by infusing balloon 22 with an expansion fluid through expansion lumen 28 . The dilation fluid may be gas or liquid, for example gas such as helium gas, CO ₂ gas, O ₂ gas, laughing gas, or liquid such as saline, contrast medium, and mixtures thereof.

Outer tube 30 and inner tube 24 are preferably made of a material that is somewhat flexible. Examples of such materials include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, or mixtures of two or more thereof, soft polyvinyl chloride resins, Polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, fluororesins such as polytetrafluoroethylene, silicone rubbers, latex rubbers, and the like.

The balloon 22 is made of a thin-film balloon film, and is made of a flexible material like the outer tube 30 and the inner tube 24 . In addition, strength to the extent that the electrode portion 40 can be reliably pushed open is also required. As the material of the balloon 22, the materials mentioned above for the outer tube 30 and the inner tube 24 can be used, and other materials may be used.

Next, the electrode section 40 will be described. The electrode portion 40 is a flexible linear member, elongated along the axis of the shaft portion 21, and provided in plurality in the circumferential direction. Although only two electrode portions 40 are shown in FIG. 1 and the like for the sake of simplification, in reality, a larger number of electrode portions 40 are provided in the circumferential direction. The interval between the electrode portions 40 is preferably in the range of 3 to 10 mm, but may be outside this range. Moreover, the electrode portions 40 may be arranged unevenly in the circumferential direction.

The distal end member 31 has a plurality of fixing holes 31a in the circumferential direction for fixing the proximal end portion of the electrode portion 40 . The number of fixing holes 31 a is equal to the number of electrode portions 40 , and the fixing holes 31 a are evenly arranged in the circumferential direction of the tip member 31 .

The distal end fixing member 45 has a plurality of accommodating portions 45a in the circumferential direction to fix the distal end portion of the electrode portion 40. As shown in FIG. The number of accommodating portions 45 a is equal to the number of electrode portions 40 , and the accommodating portions 45 a are evenly arranged in the circumferential direction of the distal end fixing member 45 .

The connection line 33 is spirally wound and embedded in the first tubular body 25 of the inner tube 24 . The connection wire 33 is pulled out from the distal end of the first tubular body 25 into the distal end fixing member 45 and connected to the distal end portion of the electrode portion 40 arranged in the housing portion 45a. Each electrode section 40 is connected to the power supply section 12 via a connection line 33 . Thereby, a voltage can be applied from the power source section 12 between the electrode sections 40 adjacent in the circumferential direction.

As shown in FIG. 3 , the electrode portion 40 includes a first portion 41 that includes a distal end portion of the electrode portion 40 and has a current-carrying portion 43, and a first portion 41 that includes a base end portion of the electrode portion 40 . is continuous in the length direction with a second portion 42 arranged on the proximal side of the . The second portion 42 is surface insulated. The first portion 41 has a conductive connection portion 54 at its tip, to which the connection line 33 is connected. In the first portion 41, the surfaces of the conductive connecting portion 54 and the conductive portion 43 exposed in the extension direction of the electrode portion 40 are conductive, and the surfaces of the other portions are insulated. The first portion 41 is formed more flexible than the second portion 42 . In addition, of the first portion 41, the distal end insulating portion 44 closer to the distal end than the conductive portion 43 is formed more flexibly. Therefore, in the electrode portion 40, the conductive portion 43 is formed more flexibly than the second portion 42, and the distal end insulating portion 44 is formed more flexibly than the conductive portion 43, respectively.

As shown in FIG. 4, the electrode section 40 is formed by laminating a plurality of layers. In FIG. 4, the lower surface is the side that contacts the balloon 22, and the upper surface is the side that contacts the living body. A conductive layer 50 is provided over almost the entire length of the electrode portion 40 . The conductive layer 50 is made of copper. However, the conductive layer 50 may be made of a material having conductivity, and may be made of a metal other than copper.

A first insulating layer 51 is provided on the lower surface side of the conductive layer 50 with an adhesive layer 56 interposed therebetween. The first insulating layer 51 is made of a hard and highly insulating resin material. Examples of such resin materials include polyimide, PET, and PEEK.

A second insulating layer 52 is provided in the region of the second portion 42 on the upper surface side of the conductive layer 50 with an adhesive layer 56 interposed therebetween. The second insulating layer 52 is made of the same material as the first insulating layer 51 . Thereby, the second portion 42 is formed of three layers, the first insulating layer 51 , the conductive layer 50 and the second insulating layer 52 , except for the adhesive layer 56 . Also, the first insulating layer 51 and the second insulating layer 52 are joined to each other by an adhesive layer 56 at the base ends thereof. As a result, the conductive layer 50 is not exposed on the base end surface of the electrode section 40 .

A surface conductive layer 55 is provided in the region of the current-carrying portion 43 on the upper surface side of the conductive layer 50 and is exposed in the extension direction of the electrode portion 40 . The surface conductive layer 55 is made of gold and has good electrical conductivity and X-ray opacity. However, the surface conductive layer 55 may be made of a material other than gold that is conductive and radiopaque. Since the conductive portion 43 has the first insulating layer 51 and the conductive layer 50 in common in the thickness direction, whether or not the conductive portion 43 is more flexible than the second portion 42 is determined depending on the flexibility of the surface conductive layer 55 . Therefore, the thickness of the surface conductive layer 55 is set so that the conductive portion 43 is more flexible than the second portion 42 .

A third insulating layer 53 and a conductive connecting portion 54 are provided in the region of the tip insulating portion 44 on the upper surface side of the conductive layer 50 . The material of the third insulating layer 53 is the same as that of the first insulating layer 51 and the second insulating layer 52 , and the thickness thereof is smaller than that of the second insulating layer 52 . As a result, the tip insulating portion 44 is formed more flexible than the second portion 42 . Further, the thickness of the third insulating layer 53 is set so that the tip insulating portion 44 is more flexible than the current-carrying portion 43 . The conductive connection portion 54 is made of the same material as the surface conductive layer 55 . The first insulating layer 51 and the third insulating layer 53 are joined to each other by an adhesive layer 56 at the tip. As a result, the conductive layer 50 is not exposed on the tip surface of the electrode section 40 .

The thickness of each layer of the electrode section 40 can be set as follows, for example. The conductive layer 50 is 10 μm thick, the first insulating layer 51 is 15 μm thick, the second insulating layer 52 is 25 μm thick, the third insulating layer 53 is 10 μm thick, and the surface conductive layer 55 is 10 μm thick. However, as described above, the thickness of each layer may be set to values other than these as long as the current-carrying portion 43 is softer than the second portion 42 and the tip insulating portion 44 is softer than the current-carrying portion 43. good.

By adjusting the thicknesses of the third insulating layer 53 and the surface conductive layer 55 in this manner, the bending elastic modulus of the first portion 41 is preferably in the range of 25 to 75% of that of the second portion 42. . However, it may be outside this range.

Moreover, although the first insulating layer 51 and the third insulating layer 53 have a constant thickness along the length direction of the electrode portion 40 in FIG. good. As a result, the tip side of the electrode portion 40 can be formed more flexibly.

As shown in FIG. 2, the electrode portion 40 has a distal end insulating portion 44 bonded to the surface of the balloon 22 by adhesion. The conducting portion 43 and the second portion 42 are not joined to the balloon 22 . However, the conducting portion 43 may be partially or entirely joined to the balloon 22 .

As the balloon 22 expands, the electrode portions 40 expand radially, as shown in FIG. Since the distal insulating portion 44 of the electrode portion 40 is bonded to the balloon 22 by adhesion as described above, it is supported by the balloon 22 and expands in diameter from the distal end to the proximal end. Moreover, it is preferable that the distal end insulating portion 44 is adhered to the balloon 22 so that there is no gap therebetween. This can prevent formation of a thrombus between the distal insulating portion 44 and the balloon 22 . The conducting portion 43 is positioned near the central portion of the balloon 22 where the diameter is the largest, is supported by the balloon 22, and adheres to the living tissue. The second portion 42 tapers from distal to proximal without contacting the balloon 22 .

In the electrode part 40, the tip insulating part 44 supported by being joined to the balloon 22 is the most flexible, the conducting part 43 supported by the balloon 22 is the second most flexible, and the second part 42 not in contact with the balloon 22 is the most flexible. It is designed to be rigid. Therefore, when the electrode section 40 is expanded at the lesion site, the electrode section 40 can be flexibly deformed according to the shape of the lesion site, and the adhesion of the electrode section 40 to the living tissue can be improved. can. In addition, since the first portion 41 is softer than the second portion 42, even if the first portion 41 is joined to the balloon 22, expansion of the balloon can be prevented.

On the other hand, since the second portion 42, which does not come into direct contact with the living tissue, is formed to be hard, deformation thereof can be suppressed when the electrode portion 40 is inserted through the valve body. Further, even if the second portion 42 is held by hand and the electrode portion 40 is inserted into the valve body, the second portion 42 has rigidity, so that the electrode portion 40 can be prevented from being deformed or destroyed. .

Next, a modified example of the electrode portion will be described. As shown in FIG. 6, the electrode section 60 of the first modified example has a first portion 60a on the distal side and a second portion 60b on the proximal side. The electrode portion 60 has a conductive layer 63 that extends over almost the entire length, and a first insulating layer 65a is provided on the lower surface side of the conductive layer 63 with an adhesive layer 69 interposed therebetween. A second insulating layer 65b is provided in the area of the second portion 60b on the upper surface side of the conductive layer 63 with an adhesive layer 69 interposed therebetween, and a surface conductive layer 68 is provided in the conductive portion 61, respectively. . The first insulating layer 65a and the second insulating layer 65b are joined by an adhesive layer 69 at the proximal end.

A third insulating layer 65 c is formed on the upper surface side of the conductive layer 63 in the tip insulating portion 62 . A conductive connecting portion 67 is also formed in the tip insulating portion 62 . The third insulating layer 65c has the same thickness as the second insulating layer 65b of the second portion 60b, and is made of a material that is more flexible than the second insulating layer 65b. The second insulating layer 65b is made of a hard resin material such as polyimide, PET, or PEEK, similar to the electrode portion 40 described above, while the third insulating layer 65c is made of a material such as nylon, urethane, or elastomer. It is made of a flexible and insulating resin material. Also, the material of the third insulating layer 65c may be a photosolder resist containing a photosensitive/thermosetting resin as a main component. The tip of the third insulating layer 65c is joined to the first insulating layer 65a via an adhesive layer 69. As shown in FIG.

In addition, in this modification, the third insulating layer 65c may be made of a material that is more flexible than the second insulating layer 65b. They may be made of similar materials and the second insulating layer 65b may be made of a harder material, or the materials of both the second insulating layer 65b and the third insulating layer 65c may be changed.

By adjusting the flexibility of the third insulating layer 65c with respect to the second insulating layer 65b by selecting the material in this manner, the bending elastic modulus of the first portion 60a is 25 to 75% of that of the second portion 60b. A range is preferred. However, it may be outside this range.

Next, the electrode portion 70 of the second modified example will be described. As shown in FIG. 7, the electrode section 70 of this modified example has a first portion 70a on the distal side and a second portion 70b on the proximal side. The electrode portion 60 has a conductive layer 73 extending over the second portion 70b and the current-carrying portion 71. On the lower surface side of the conductive layer 73, a first insulating layer 75a extends over the entire length of the electrode portion 70 with an adhesive layer 79 interposed therebetween. formed by On the upper surface side of the conductive layer 73, a second insulating layer 75b is formed in the region of the second portion 70b, and a surface conductive layer 78 is formed in the region of the conductive portion 71, respectively. A third insulating layer 75c is formed on the tip insulating portion 72 on the upper surface side of the first insulating layer 75a with an adhesive layer 79 interposed therebetween. That is, in this modified example, the tip insulating portion 72 does not have the conductive layer 73, and accordingly, the tip insulating portion 72 is thinner than the second portion 70 and formed flexibly.

In this modification, since the tip insulating portion 72 does not have the conductive layer 73 , the conductive connecting portion 77 is formed in the second portion 70 . For this reason, the connection line 33 from the power source section 12 is connected to the proximal end portion of the electrode section 70 unlike the examples described so far.

By changing the layer structure of each part constituting the electrode part 70 in this way, the bending elastic modulus of the first part 70a is preferably in the range of 25 to 75% of that of the second part 70b. However, it may be outside this range.

Also in this example, the thickness of the first insulating layer 75a and the third insulating layer 75c may gradually decrease toward the distal end side. As a result, the tip side of the electrode portion 70 can be formed more flexibly.

Also, two or three of the configurations of the distal end insulating portions described above may be adopted at the same time. For example, like the electrode part 40, the thickness of the third insulating layer 53 is made smaller than that of the second insulating layer 52, and like the electrode part 60, the material of the third insulating layer 65c is made more flexible than the second insulating layer 65b. Further, unlike the electrode portion 70, the conductive layer 73 is not provided on the portion of the tip insulating portion 72, and the third insulating layer 75c is formed on the upper surface side of the first insulating layer 75a with the adhesive layer 79 interposed therebetween. You may do so.

Next, the electrode portion 80 of the third modified example will be described. As shown in FIG. 8, the electrode section 80 of the third modification has a first portion 80a on the distal side and a second portion 80b on the proximal side. The configuration of the first portion 80a is the same as that of the electrode portion 40 of FIG. A first insulating layer 85a is provided on one side of the conductive layer 83, and a surface conductive layer 88, a third insulating layer 85c, and a conductive connecting portion 87 are provided on the other side. The second portion 80b is formed of one layer of the second insulating layer 85b. Thus, the second portion 80b may be formed of only one layer. Also in this case, the bending elastic modulus of the first portion 80a is preferably in the range of 25 to 75% of that of the second portion 80b. However, it may be outside this range.

Next, electrode portions 90, 100 and 110 of fourth to sixth modifications will be described. Each of these forms the first portion flexibly by a notch portion in the width direction of the tip insulating portion. As shown in FIG. 9A, the electrode portion 90 of the third modification has a second portion 90b and a first portion 90a having a conductive portion 91 and a tip insulating portion 92. As shown in FIG. The tip insulator 92 is narrower than the second portion 90b. As a result, notches 94 that are spaced in the width direction are formed on both sides of the tip insulating portion 92 . The first portion 90a is formed more flexible than the second portion 90b because the tip insulating portion 92 has the notch portion 94. As shown in FIG. The width of the notch portion 94 changes the width of the tip insulating portion 92, and the flexibility can be adjusted. Also in this example, the flexural modulus of the first portion 90a is preferably in the range of 25 to 75% of that of the second portion 90b, but may be outside this range.

As shown in FIG. 9B, the electrode portion 100 of the fourth modification has a second portion 100b and a first portion 100a having a conducting portion 101 and a tip insulating portion 102. As shown in FIG. The tip insulating portion 102 has a plurality of notch portions 104 that are partially notched on both sides. The notch 104 makes the first portion 100a more flexible than the second portion 100b. The flexibility of the first portion 100a can be adjusted by the size and number of the notches 104. FIG. Also in this example, the flexural modulus of the first portion 100a is preferably in the range of 25 to 75% of that of the second portion 100b, but may be outside this range.

As shown in FIG. 9C, the electrode portion 110 of the fifth modification has a second portion 110b and a first portion 110a having a conducting portion 111 and a tip insulating portion 112. As shown in FIG. A plurality of hole-shaped notch portions 114 are formed in the tip insulating portion 112 . The notch 114 makes the first portion 110a more flexible than the second portion 110b. The flexibility of the first portion 110a can be adjusted by the size and number of the notches 114. FIG. Also in this example, the flexural modulus of the first portion 110a is preferably in the range of 25 to 75% of that of the second portion 110b, but may be outside this range.

Also, by combining the fourth to sixth modified examples with the configuration of the electrode portion described before, the first portion may be formed more flexibly than the second portion.

Next, a medical device 120 of a second embodiment will be described. While the first embodiment uses a balloon 22 to expand the electrode portion 40, the second embodiment does not have a balloon. As shown in FIG. 10, the shaft portion 121 has an outer tube 122 and an inner tube 123, and the inner tube 123 inserted through the lumen of the outer tube 122 has a single lumen. A fixing member 125 is provided at the distal end portion of the outer tube 122 to fix the proximal end portion of the electrode portion 124 . A distal end fixing member 126 is provided at the distal end portion of the inner tube 123 to fix the distal end portion of the electrode portion 124 . For the electrode portion 124, either the electrode portion 40 of the first embodiment or the electrode portion of its modification can be used as it is. The operator can expand the electrode section 124 by pulling the inner tube 123 in the axial direction with respect to the outer tube 122 .

Next, an example of a treatment method using the medical device 10 will be described. First, an introducer (not shown) is percutaneously punctured into a blood vessel by the Seldinger method or the like. Next, after inserting a guide wire (not shown), a guiding catheter (not shown) is inserted into the introducer. It is inserted into the blood vessel through the orifice. After that, while leading the guide wire, the guiding catheter is gradually advanced to the target site.

Next, with the balloon 22 and the electrode section 40 contracted, the distal end of the guide wire is inserted into the distal end opening of the guide wire lumen 27 of the inner tube 24 and the guide wire is pulled out from the hub 23 . Next, the medical device 10 is inserted from the distal end into the guiding catheter inserted into the blood vessel, and the electrode section 40 and the shaft section 21 are advanced along the guide wire. When inserting the electrode section 40 into the guiding catheter, the second section 42 of the electrode section 40 is held by hand and inserted into the guiding catheter from the first section 41 . Since the second portion 42 is harder than the first portion 41, the electrode portion 40 can be inserted without being damaged.

After the electrode section 40 is inserted to the target position, the expansion fluid is supplied into the balloon 22 through the expansion lumen 28 to expand the balloon 22 . As a result, as shown in FIG. 5, the electrode 40 is radially expanded by the balloon 22 . In this state, voltage is applied between the electrodes 40 from the power supply section 12 .

After completing the voltage application, the balloon 22 and the electrode section 40 are contracted. After that, all instruments inserted into the blood vessel are withdrawn, and the procedure is completed.

As described above, the medical device 10 according to the present embodiment includes an elongated shaft portion 21 and an electrode disposed at the distal end portion of the shaft portion 21, elongated along the axis of the shaft portion 21, and expandable in the radial direction. a portion 40, wherein the electrode portion 40 includes a first portion 41 including a distal end portion of the electrode portion 40 and a proximal end portion of the electrode portion 40, and is disposed on the proximal side of the first portion 41; The first portion 41 has a conductive portion 43 including a surface conductive layer 55 exposed in the direction in which the electrode portion 40 extends, and the second portion 42 has an electrically conductive portion 43 including a surface conductive layer 55 exposed in the extension direction of the electrode portion 40 . flexibly formed. As a result, since the first portion 41 of the electrode portion 40 that contacts the lesion is flexible and the other portions are hard, it is possible to achieve both adhesion of the electrode portion 40 to the lesion and suppression of deformation by the valve body. can be done. Moreover, by holding the first portion of the electrode portion 40 by hand, it is possible to prevent the electrode portion 40 from being damaged during insertion.

The first portion 41 has a distal insulating portion 44 on the distal end side and a conducting portion 43 on the proximal side. If it is formed more flexible than the portion 43, discontinuity of flexibility in the length direction can be alleviated.

Further, if the first portion 41 is formed flexibly by being thinner than the second portion 42, the first portion 41 can be easily formed flexibly by adjusting the thickness.

In addition, if the first portion 60a is made of a material that is more flexible than the second portion 60b, the first portion 60a can be easily formed flexibly by selecting the material. can.

In addition, the electrode portion 70 is formed by laminating a plurality of layers, and the first portion 70a has fewer layers than the second portion 70b. By doing so, the first portion 70a can be easily and flexibly formed.

Moreover, if the first portion 80a is formed flexibly by having a notch 84 in the width direction in at least a part of the length direction of the electrode portion 40, the shape, size and shape of the notch 84 can be adjusted. The first portion 80a can be easily and flexibly formed by setting the number and the like.

The shaft portion 21 includes an elongated outer tube 30 and an inner tube 24 that is inserted through the outer tube 30 so as to protrude from the distal end portion of the outer tube 30 and is slidable in the axial direction with respect to the outer tube 30 . , the distal end of the electrode section 40 is fixed to the distal end of the inner tube 24, and the proximal end of the electrode section 40 is fixed to the distal end of the outer tube 30, By sliding the outer tube 30 and the inner tube 24 in the axial direction, the electrode section 40 having a flexible portion can be expanded and contracted.

A balloon 22 for expanding the electrode portion 40 is provided at the distal end portion of the shaft portion 21 , and the electrode portion 40 is made flexible by connecting at least a portion of the first portion 41 to the balloon 22 . Since the first portion 41 is joined to the balloon 22 , the expansion of the balloon 22 can be prevented from being hindered by the electrode portion 40 .

Further, if the second portion 42 does not come into contact with the expanded balloon 22, only the flexible region of the electrode section 40 is brought into contact with the living tissue, and the adhesion of the electrode section 40 can be improved. .

The present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical concept of the present invention. For example, although the electrode portion in each example is provided with one current-carrying portion, it may have a plurality of current-carrying portions. In this case, the current-carrying parts can be connected in series or in parallel.

Further, the electrode portion of each example in which a plurality of layers are laminated may further have layers other than these.

REFERENCE SIGNS LIST 10 medical device 12 power source 20 balloon catheter 21 shaft 22 balloon 23 hub 24 inner tube 25 first tubular body 26 second tubular body 27 guidewire lumen 28 expansion lumen 30 outer tube 31 tip member 33 connecting wire 40 electrode section 41 second Part 1 42 Second part 43 Current-carrying part 44 Tip insulating part 45 Tip fixing member 50 Conductive layer 51 First insulating layer 52 Second insulating layer 53 Third insulating layer 54 Conductive connecting part 55 Surface conductive layer 56 Adhesive layer

Claims (9)

a long shaft and
an electrode portion disposed at a distal end portion of the shaft portion, elongated along the axis of the shaft portion and radially expandable;
The electrode portion includes a first portion including a distal end portion of the electrode portion, and a second portion including a proximal end portion of the electrode portion, disposed on the proximal side of the first portion, and having an insulated surface. having a part and
The medical device, wherein the first portion has a conducting portion including a surface conductive layer exposed in an extending direction of the electrode portion, and is formed more flexibly than the second portion. The first portion has a distal insulating portion arranged at the distal end portion of the electrode portion, and the conductive portion arranged proximally from the distal insulating portion,
The medical device according to claim 1, wherein the conducting portion is formed more flexible than the second portion, and the tip insulating portion is formed more flexible than the conducting portion. 3. The medical device of claim 1 or 2, wherein the first portion is formed flexibly by being thinner than the second portion. 3. The medical device of claim 1 or 2, wherein the first portion is made flexible by having a material that is softer than the second portion. 3. The medical device according to claim 1, wherein the electrode section is formed by laminating a plurality of layers, and the first section is formed flexibly by having fewer layers than the second section. The medical device according to claim 1 or 2, wherein the first portion is formed flexibly by having a notch portion in the width direction in at least part of the length direction of the electrode portion. The shaft portion has an elongated outer tube and an inner tube that is inserted through the outer tube so as to protrude from the tip of the outer tube and is slidable in the axial direction with respect to the outer tube,
7. A distal end portion of the electrode portion is fixed to a distal end portion of the inner tube, and a proximal end portion of the electrode portion is fixed to a distal end portion of the outer tube. A medical device as described in . 8. The tip of the shaft portion is provided with a balloon for expanding the electrode portion, and the electrode portion has at least a portion of the first portion joined to the balloon. A medical device according to paragraph. 9. The medical device of Claim 8, wherein the second portion does not contact the expanded balloon.

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