WO2019181634A1

WO2019181634A1 - Medical device

Info

Publication number: WO2019181634A1
Application number: PCT/JP2019/009870
Authority: WO
Inventors: 大久保到; 周拓
Original assignee: テルモ株式会社
Priority date: 2018-03-20
Filing date: 2019-03-12
Publication date: 2019-09-26
Also published as: JPWO2019181634A1; JP7279018B2

Abstract

Provided is a medical device which has good followability to a dilator and can eliminate sliding between shafts. This medical device (10) includes a long shaft portion (21), a dilator (22) that is provided on a distal end of the shaft portion (21), and a plurality of electrode portions (40) that are provided around the dilator (22) along a length direction. Each of the plurality of electrode portions (40) has a stretchable portion (43) at least a portion of which is stretchable in the length direction. Additionally, each electrode portion (40) has a distal end fixed more to the distal end side than the dilator (22) of the shaft portion (21) and a base end fixed more to the proximal end side than the dilator (22) of the shaft portion (21), and is deformable independent of the dilator (22).

Description

Medical device

The present invention relates to a medical device that is inserted into a living body and performs treatment by ablation on a living tissue.

A medical device that performs treatment by irreversible electroporation (IRE) is known. Irreversible electroporation is attracting attention because it is non-thermal and can suppress damage to surrounding blood vessels and nerves. For example, medical devices are known that treat cancer that is difficult to remove by surgery using irreversible electroporation.

For atrial fibrillation caused by abnormal excitation in the myocardial sleeve of the pulmonary vein wall, pulmonary vein isolation may be performed to ablate the junction between the pulmonary vein and the left atrium and destroy myocardial cells . In pulmonary vein isolation, a high frequency is generated from the distal end of the ablation catheter, and the myocardium is cauterized into points to cause necrosis. The ablation catheter is moved so as to cauterize the pulmonary vein inflow portion and isolate the pulmonary vein.

It is conceivable to apply the above-described irreversible electroporation method when treating a living body lumen in this way. Examples of medical devices that apply irreversible electroporation to a living body lumen include those shown in the following patent documents. Patent Document 1 discloses a medical device having an electrode to which irreversible electroporation can be applied to an arterial lesion. Patent Document 2 discloses a medical device that can be inserted into a ventricle and can reduce myocardial tissue by irreversible electroporation. Patent Document 3 discloses a medical device in which an expansion element is provided at the distal end portion of an elongated body, and an electroporation treatment portion is further provided at the distal end side. Patent Document 4 discloses a medical device in which a plurality of electrodes are provided at a distal end portion and electric power is supplied to the electrodes to perform electroporation treatment.

US Patent Publication No. 2009/0248012 International Publication No. 2014/195933 Specification US Patent Publication No. 2013/0110098 US Patent Publication No. 2014/0066913

When a plurality of electrodes are arranged around the balloon and the electrodes are expanded and deformed in the radial direction by expanding the balloon, the electrodes are uniformly expanded and deformed in the circumferential direction. For this reason, when the surface of the balloon expands unevenly in the circumferential direction, the deformation of the electrode cannot follow the expansion of the balloon, and the electrode may float from the surface of the balloon.

Also, the distance between the distal end portion and the proximal end portion of the electrode changes with expansion deformation. As a result, a slide along the axial direction occurs between the balloon-side shaft and the electrode-side shaft, and blood may enter the shaft through a gap necessary for the slide.

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 that has good followability to an expansion body and can eliminate sliding between shafts.

The medical device according to the present invention that achieves the above object includes a long shaft portion, an expansion body provided at a tip portion of the shaft portion, and a plurality of electrodes provided along the length direction around the expansion body. Each of the plurality of electrode portions has a stretchable portion that can be stretched and contracted in the length direction.

When the expansion body expands, the medical device configured as described above can be deformed while the electrode section follows the expansion of the expansion body because the electrode section can expand and deform in the radial direction while the expansion and contraction section expands. Further, since the electrode portion itself can be expanded and contracted, it is not necessary to provide a shaft that slides in accordance with the deformation of the electrode portion, and sliding between the shafts can be eliminated.

It is a front view which shows the outline of the medical device in 1st Embodiment. It is sectional drawing of the front-end | tip part vicinity of a medical device. It is a front view at the time of expansion and contraction of the expansion / contraction part formed with the spring member. It is a front view at the time of the expansion | extension part formed by the bellows member at the time of shrinkage | contraction. It is sectional drawing which cut the front-end | tip part of the medical device with the plane perpendicular | vertical to an axial direction. It is sectional drawing of the front-end | tip part vicinity of the medical device of the state which expanded the balloon. It is a front view near the front-end | tip part of the medical device in 2nd Embodiment. It is a front view near the front-end | tip part of the medical device in 3rd Embodiment. It is a top view of the electrode part formed with the rubber member.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio. Further, in this specification, the side of the medical device 10 to be inserted into the living body lumen is referred to as “tip” or “tip side”, and the proximal side for operation is referred to as “base end” or “base end side”.

The medical device 10 according to the first embodiment is inserted percutaneously into a living body lumen, and is subjected to irreversible electroporation by applying a current by contacting a living tissue at a target site. The medical device 10 of this embodiment is intended for a treatment in which electroporation is performed over the entire circumference of the pulmonary vein entrance in pulmonary vein isolation. However, as will be described later, the medical device according to the present invention can be applied to other treatments.

As shown in FIG. 1, the medical device 10 includes a long shaft portion 21, a balloon 22 that is an expansion body provided at the distal end portion of the shaft portion 21, and a hub 23 provided at the proximal end portion of the shaft portion 21. And a plurality of electrode portions 40 provided around the balloon 22.

The shaft portion 21 has a connection line 37 for applying a voltage to the electrode portion 40 along the length direction. The connection line 37 is drawn from the proximal end portion of the shaft portion 21 and is connected to the power supply portion 12 provided outside the shaft portion 21. The power supply unit 12 can apply a high voltage to the electrode unit 40 in a pulsed manner.

The structure near the tip of the medical device 10 will be described in detail. As shown in FIG. 2, the shaft portion 21 has an outer tube portion 30 and an inner tube portion 31 concentrically. Inside the inner tube portion 31, a guide wire lumen 32 is formed along the length direction. An expansion lumen 33 is formed inside the outer tube portion 30 and outside the inner tube portion 31.

The distal end portion of the outer tube portion 30 is located inside the balloon 22. An expansion opening 34 that connects the expansion lumen 33 and the inside of the balloon 22 is formed at the distal end of the outer tube portion 30. The balloon 22 can be expanded by injecting an expansion fluid into the balloon 22 through the expansion lumen 33 and the expansion opening 34. The expansion fluid may be a gas or a liquid. For example, a gas such as helium gas, CO ₂ gas, O ₂ gas, or laughing gas, or a liquid such as physiological saline, a contrast medium, or a mixture thereof can be used.

The inner tube portion 31 extends further to the distal end side than the distal end of the outer tube portion 30, and the distal end portion is located on the distal end side from the balloon 22. The balloon 22 has a proximal end portion fixed to the outer surface of the outer tube portion 30 and a distal end portion fixed to the outer surface of the inner tube portion 31.

A telescopic part lumen 35 for accommodating the base end part of the electrode part 40 is formed on the outermost peripheral part of the shaft part 21. The expansion / contraction portion lumen 35 is open toward the distal end side on the proximal end side from the balloon 22. A connection part 36 for electrically connecting the electrode part 40 and the connection line 37 is provided at the innermost part of the expansion / contraction part lumen 35. A plurality of the stretchable part lumens 35 are provided in the circumferential direction so as to respectively correspond to the electrode parts 40 provided in the circumferential direction.

The shaft portion 21 is preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these, soft polyvinyl chloride resin, Examples thereof include fluororesins such as polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, polytetrafluoroethylene, silicone rubber, and latex rubber.

The balloon 22 is formed of a thin-film balloon film, and is formed of a flexible material, like the shaft portion 21. Moreover, the intensity | strength of the grade which spreads the electrode part 40 reliably is also required. As the material of the balloon 22, those described above for the shaft portion 21 can be used, and other materials may be used.

The electrode part 40 is formed of a wire material having conductivity and flexibility. The electrode part 40 of this embodiment is formed of a superelastic metal typified by nickel titanium. However, you may form the electrode part 40 with the material which has the other electroconductivity. For example, an FPC (flexible printed circuit board) may be used. The part formed with the wire of the electrode part 40 does not have a stretching property in the length direction.

The electrode part 40 is fixed to the shaft part 21 in the first fixing part 35a on the proximal end side from the balloon 22. The electrode portion 40 is fixed to a tip fixing member 45 provided on the shaft portion 21 at a second fixing portion 45 a on the tip side of the balloon 22. The tip fixing member 45 is fixed to the inner tube portion 31 of the shaft portion 21. The electrode part 40 is located on the outer peripheral side of the balloon 22 and is not fixed to the balloon 22.

The electrode part 40 has a conduction part 41 in a region arranged around the balloon 22. The conduction | electrical_connection part 41 is an area | region where the surface is not insulated, and can apply an electric current with respect to a biological tissue when it contacts with a biological tissue. A region other than the conductive portion 41 of the electrode portion 40 is an insulating portion 42, and an insulating coat is applied to the surface. The insulating part 42 does not apply a current to the living tissue.

The base part of the electrode part 40 is provided with a stretchable part 43 that can be stretched in the length direction. As shown in FIG. 3A, the stretchable portion 43 is formed by a coiled spring member. The expansion / contraction part 43 being expandable / contractible means that the electrode part 40 can be expanded and contracted in the length direction. The flexible material generally has flexibility in the bending direction, and may be able to expand and contract in the length direction. When the stretchable portion 43 is formed using the flexibility of the material and is stretched and contracted in the length direction, the diameter of the stretchable portion 43 changes due to expansion and contraction, so that the electrical resistance also changes. By making the stretchable portion 43 stretchable not by the flexibility of the material but by changing its shape, it can be stretched and contracted in the length direction without changing the electrical resistance. In this embodiment, the spring member forming the stretchable portion 43 has good conductivity to the electrode portion 40 and durability during the stretch, and can be easily joined to the wire portion of the electrode portion 40 by soldering. The stretchable part 43 is formed of a conductive material, for example, a metal. Further, the stretchable part 43 may be formed of a stretchable FPC or a curled covered electric wire, or may be formed of other conductive materials. As shown in FIG. 3B, the stretchable portion 43 can extend in the length direction from the state of FIG. In addition, an insulating coat is applied to the surface of the stretchable portion 43 in order to prevent current from being applied to the living tissue that is not the target site.

The stretchable portion 43 may be a bellows member as shown in FIG. In this case, the expansion and contraction can be extended in the length direction as shown in FIG. The stretchable portion 43, which is a bellows member, can also be formed of a conductive metal, FPC, or other material.

The stretchable portion 43 may be other than a spring member or a bellows member as long as it is an elastic body that has conductivity and can be stretched in the length direction. For example, a linear rubber member having conductivity can be used. As the rubber member having conductivity, for example, rubber containing carbon nanotubes, or a material in which a conduction path is printed with a conductive ink on the rubber surface can be used. When a rubber member is used for the stretchable part 43, the stretchable part 43 may not be stored in the stretchable part lumen 35.

The expansion / contraction part 43 is accommodated in the expansion / contraction part lumen 35 of the shaft part 21. The distal end portion of the stretchable portion 43 is joined to the wire portion of the electrode portion 40 by soldering and is electrically connected. The base end portion of the expansion / contraction part 43 is joined to the connection line 37 drawn into the connection part 36 by soldering, and is electrically connected. The surface of the stretchable part 43 including the joints at both ends is subjected to an insulation coating or insulation treatment. The bonding method may be laser welding or welding using various metal brazing.

In FIG. 1 and the like, only two electrode portions 40 are shown for simplification, but a large number of electrode portions 40 are provided in the circumferential direction as shown in FIG. In this embodiment, six electrode portions 40 are equally provided in the circumferential direction. However, the number of electrode portions 40 may be larger or smaller than this. Moreover, the electrode part 40 may be unevenly arrange | positioned in the circumferential direction. The voltage is applied between the adjacent electrode portions 40, but an electrode may be disposed outside the body, and the voltage may be applied between the electrode outside the body and the electrode portion 40. The electrode part 40 has the conduction | electrical_connection part 41 in the surface of the outer peripheral side which contacts a biological tissue. A surface other than the outer peripheral surface of the electrode portion 40 is an insulating portion 42 that is coated with an insulating coating.

As shown in FIG. 6, when the balloon 22 is expanded, the electrode portion 40 is expanded and deformed in the radial direction by the expansion force of the balloon 22. As a result, the electrode unit 40 is pressed against the living tissue. When the electrode part 40 expands and deforms in the radial direction, the stretchable part 43 extends in the stretchable part lumen 35. Each of the plurality of electrode portions 40 in the circumferential direction is provided with a stretchable portion 43, and the electrode portion 40 and the stretchable portion 43 are independent of the balloon 22, so that the stretchable portion 43 of each electrode portion 40 is provided. Can be of different lengths. The balloon 22 has a non-uniform shape in the circumferential direction depending on the shape of the inserted living body lumen. In particular, a non-uniform shape in the circumferential direction of the living body lumen is often seen in a transition portion between a wide space such as in the heart chamber and a narrow space such as a blood vessel. Examples include the pulmonary vein entrance and the left atrial appendage entrance. Even in this case, each of the stretchable parts 43 can be extended independently, so that the electrode part 40 can be expanded and deformed while following the shape of the balloon 22. Thereby, the electrode part 40 follows the shape of a biological lumen, and can apply an electric current reliably with respect to the target site | part.

In this embodiment, the electrode unit 40 is not fixed to the balloon 22, but the electrode unit 40 may be fixed to the surface of the balloon 22. In this case, it is necessary to prevent the stretchable portion 43 from being fixed to the balloon 22. Thereby, the expansion-contraction part 43 can be extended so that the electrode part 40 may follow the expansion of the balloon 22 and deform | transform.

Next, 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, the guide wire is protruded toward the distal end side, and the distal end portion of the guiding catheter is inserted into the introducer. Insert into the blood vessel through the tip opening. Thereafter, the guiding catheter is gradually pushed to the target site while the guide wire is advanced. The surgeon forms a through hole in the atrial septum by penetrating a predetermined puncture device from the right atrium side toward the left atrium side. As the puncture device, for example, a device such as a wire with a sharp tip can be used. Delivery of the puncture device can be performed via a guiding catheter. In addition, the puncture device can be delivered to the atrial septum instead of the guide wire after the guide wire is removed from the guiding catheter, for example. In addition, the specific structure of the puncture device used for the penetration of the atrial septum, the specific procedure for forming the through hole, etc. are not particularly limited. After forming the through hole, the dilator is used to expand the through hole, the guiding catheter is passed through the through hole, and the guide wire is used to push the target hole (for example, near the pulmonary vein). The guiding catheter may have a mechanism for moving the distal end portion of the guiding catheter.

Next, the end of the guide wire is inserted into the opening of the distal end portion of the guide wire lumen 32 of the shaft portion 21, and the guide wire is taken out from the hub 23. Next, the medical device 10 is inserted into the guiding catheter inserted into the blood vessel from the distal end portion and pushed along the guide wire.

When the electrode unit 40 is inserted to the entrance of the pulmonary vein, which is the target position, the expansion fluid is supplied into the balloon 22 via the expansion lumen 33, and the balloon 22 is expanded. Thereby, as shown in FIG. 6, the expansion / contraction part 43 expand | extends, it becomes the shape which the electrode part 40 expanded to radial direction with the balloon 22, and the electrode part 40 is pressed on a biological tissue. In this state, a voltage is applied from the power supply unit 12 to the electrode unit 40.

First, a pulsed voltage is applied from the power supply unit 12 to a pair of

electrode units

40 and 40 adjacent in the circumferential direction. Thereby, an electric current flows between a pair of

electrode parts

40 and 40 adjacent to the circumferential direction. Next, a pulsed voltage is applied to the other pair of

electrode portions

40, 40 adjacent in the circumferential direction. The application of voltage is sequentially performed on all pairs of

electrode portions

40, 40 that are adjacent in the circumferential direction. An example of the applied voltage is given below. The electric field strength applied by the power supply unit 12 is 1500 V / cm, and the voltage pulse width is 100 μsec. The voltage application to all pairs of the electrode portions 40 adjacent in the circumferential direction is repeated 60 to 180 times in a cycle of once every 2 seconds in accordance with the refractory period of the ventricular muscle. As a result, cells at the entrance of the pulmonary vein are necrotized over the entire circumference.

When the voltage application is completed, the balloon 22 is deflated. Thereby, the electrode part 40 also shrinks in the radial direction. Thereafter, all instruments inserted into the blood vessel are removed to complete the procedure.

Next, the medical device 50 according to the second embodiment will be described. About the structure which is common with the medical device 10 of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 7, the medical device 50 according to the present embodiment has a distal end side expansion / contraction section lumen 56 on the distal end fixing member 55. The electrode portion 51 has a proximal end side stretchable portion 52 at the proximal end portion and a distal end side stretchable portion 53 at the distal end portion. The base end side expansion / contraction part 52 is accommodated in the expansion / contraction part lumen 35 of the shaft part 21. The distal-side expansion / contraction part 53 is accommodated in the distal-end-side expansion / contraction part lumen 56 of the distal end fixing member 55.

Thus, the base end side stretchable part 52 and the tip end side stretchable part 53 can also be provided at the base end part and the tip end part of the electrode part 51, respectively. Thereby, each elongation amount of the base end side expansion-contraction part 52 and the front end side expansion-contraction part 53 can be made small, and frictional resistance can be made small. As in the first embodiment, a spring member, a bellows member, a rubber member, or the like can be used for the base end side stretchable portion 52 and the distal end side stretchable portion 53. The base end side expansion / contraction part 52 needs to have conductivity for electrical connection with the electrode part 51. The distal end side stretchable part 53 may not have conductivity.

Alternatively, the electrode part 51 may be provided with the distal end side stretchable part 53 and the proximal end side stretchable part 52 may not be provided. When only the expansion / contraction part 43 on the proximal end side of the electrode part 40 is provided as in the first embodiment, the positional relationship between the distal end of the shaft part 21 and the electrode part 40 is fixed. Easy to grasp the position at the time of deformation and easy to operate. On the other hand, when only the distal end side stretchable portion 53 is provided on the electrode portion 51, the distal end side stretchable portion 53 can be formed of a material having no conductivity, and the base end portion of the electrode portion 51 is directly connected to the connection line 37. be able to.

Next, a medical device 60 according to the third embodiment will be described. About the structure which is common with the medical device 10 of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 8, the medical device 60 of the present embodiment has an electrode part 61 whose whole length direction is an expandable part. The electrode portion 61 is formed of a material that can be elastically expanded and contracted, for example, rubber. However, it may be formed of other materials such as a stretchable resin. The electrode portion 61 has a proximal end portion fixed to the shaft portion 21 and a distal end portion fixed to the distal end fixing member 45.

As shown in FIG. 9, in the electrode part 61, a conductive part 61b having conductivity is formed on the surface of a base part 61a made of rubber. Since the area | region of the conduction | electrical_connection part 61b is exposed on the surface of the electrode part 61, when the electrode part 61 expands and deforms, the conduction | electrical_connection part 61b is formed in the surface which contacts a biological tissue. The conduction part 61b can be formed by printing conductive ink on the surface of the base part 61a.

The electrode portion 61 is formed with a continuous portion 61c extending from the proximal end of the conducting portion 61b toward the proximal end side. The continuous portion 61c is also formed together with the conductive portion 61b by printing conductive ink on the surface of the base portion 61a. A base end portion of the continuous portion 61 c is electrically connected to the connection line 37. Thereby, the conduction | electrical_connection part 61b and the connection line 37 are electrically connected. The surface of the continuous part 61 c is provided with an insulating coat so as not to be exposed on the surface of the electrode part 61. Further, for example, the conducting part 61b and the continuous part 61c of the electrode part 61 may be formed of rubber containing a conductive member such as a carbon nanotube or copper particles. Other portions may be formed of rubber that does not contain a conductive material.

Thus, the entire electrode part 61 can also be formed of a stretchable part. The electrode portion 61 expands by expansion of the balloon 22 and expands and deforms in the radial direction together with the balloon 22. Since the whole electrode part 61 is an extension part, the connection part of a wire and an extension part can be eliminated, and the electrode part 61 can be made into a simple structure.

In this embodiment, the electrode unit 61 is not fixed to the balloon 22, but the electrode unit 61 may be fixed to the surface of the balloon 22. In this case, expansion of the balloon 22 causes the membrane of the balloon 22 to expand, and the electrode portion 61 also expands and expands and deforms in the radial direction.

As described above, the medical device 10 according to the present embodiment is provided along the length direction around the elongated shaft portion 21, the expansion body 22 provided at the distal end portion of the shaft portion 21, and the expansion body 22. In the medical device 10 having a plurality of electrode portions 40, each of the electrode portions 40 has a stretchable portion 43 that is at least partially stretchable in the length direction. Accordingly, when the expansion body 22 is expanded, the electrode portion 40 can be expanded and deformed in the radial direction while the expansion / contraction portion 43 is extended. Therefore, the electrode portion 40 can be deformed while following the expansion of the expansion body 43. Moreover, since the electrode part 40 itself can be expanded and contracted, it is not necessary to provide a shaft that slides in accordance with the deformation of the electrode part 40, and sliding between the shafts can be eliminated.

The electrode portion 40 has a base end portion and a tip end portion, and the shaft portion 21 has a first fixing portion 35a to which the base end portion of the electrode portion 40 is fixed and a tip end portion of the electrode portion 40 fixed. The second fixing portion 45a, the first fixing portion 35a is located on the proximal end side of the expansion body 22, the second fixing portion 45a is located on the distal end side of the expansion body 22, and the electrode The part 40 can be deformed independently of the expansion body 22. Thereby, the expansion body 22 can be freely expanded according to the shape of the living body lumen, and the electrode portion 40 can be deformed following the expansion.

Moreover, if the expansion-contraction part 43 is arrange | positioned at the base end side of the electrode part 40, since the positional relationship of the electrode part 40 and the front-end | tip of the shaft part 21 is fixed, the electrode part 40 is made into the target site | part. It is easy to position and can improve operability.

Further, if the stretchable portion 53 is arranged on the tip side of the electrode portion 40, a material that does not have conductivity can be used for the stretchable portion 53.

Further, if the

stretchable parts

52 and 53 are arranged on the proximal end side and the distal end side of the electrode part 40, respectively, the stretch amount of each

stretchable part

52 and 53 can be reduced, and the frictional resistance can be reduced.

Further, if the expansion / contraction part 43 is a spring member, it can be easily connected to the connection line 37 and can be manufactured easily, and the durability can be increased.

Moreover, if the shaft part 21 has the expansion-contraction part lumen | rumen 35 which accommodates the expansion-contraction part 43, the expansion-contraction part 43 can be expanded-contracted, without interfering with the exterior.

Further, if the stretchable portion 43 is a rubber member having stretchability, it is not necessary to provide a lumen for the stretchable portion 43 in the shaft portion 21.

Moreover, the electrode part 61 is a rubber member having elasticity, and if the conductive part 61b is provided on at least a part of the surface of the rubber member, the connection between the electrode part and the extension part becomes unnecessary, and the manufacture of the parts is simplified. Can be

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, although the medical device 10 according to the above-described embodiment is used for the treatment of the pulmonary vein, it may be used to treat other parts such as the renal artery, the ascending vena cava, and the ventricle.

Note that this application is based on Japanese Patent Application No. 2018-052493 filed on Mar. 20, 2018, the disclosures of which are incorporated by reference in their entirety.

DESCRIPTION OF SYMBOLS 10 Medical device 12 Power supply part 21 Shaft part 22 Balloon 23 Hub 30 Outer pipe part 31 Inner pipe part 32 Guide wire lumen 33 Expansion lumen 34 Expansion opening part 35 Telescopic part lumen 36 Connection part 37 Connection line 40 Electrode part 41 Conduction part 42 Insulating part 43 Extendable part 45 Tip fixing member

Claims

A medical device having a long shaft portion, an expansion body provided at a tip portion of the shaft portion, and a plurality of electrode portions provided along the length direction around the expansion body,
Each of the plurality of electrode portions is a medical device having at least a stretchable portion that can be stretched in the length direction.
The electrode portion has a proximal end portion and a distal end portion,
The shaft portion includes a first fixing portion to which a base end portion of the electrode portion is fixed, and a second fixing portion to which a tip portion of the electrode portion is fixed,
The first fixing portion is located on the proximal side from the expansion body,
The second fixing portion is located on the distal end side of the expansion body,
The medical device according to claim 1, wherein the electrode part is deformable independently of the expansion body.
The medical device according to claim 1 or 2, wherein the stretchable part is disposed on a proximal end side of the electrode part.
The medical device according to claim 1 or 2, wherein the stretchable part is disposed on a distal end side of the electrode part.
The medical device according to claim 1 or 2, wherein the stretchable part is disposed on a proximal end side and a distal end side of the electrode part, respectively.
The medical device according to any one of claims 1 to 5, wherein the stretchable portion is a spring member.
The medical device according to claim 6, wherein the shaft portion has a stretchable portion lumen that houses the stretchable portion.
The medical device according to any one of claims 1 to 5, wherein the stretchable portion is a rubber member having stretchability.
The medical device according to claim 1 or 2, wherein the electrode part is a rubber member having elasticity, and a conductive part is provided on at least a part of the surface of the rubber member.