Incision instrument

1. An incision instrument comprising:

an insertion section that is configured to be inserted into a body; and

a manipulation section provided at a proximal end of the insertion section;

wherein the insertion section comprises:

a first insulating member which has an elongated tubular shape, and

an incision section inserted within the first insulating member;

wherein the incision section comprises:

a first conductive member which has a tubular shape and has conductivity;

a second conductive member disposed so as to movable inside the first conductive member along a longitudinal axis of the first conductive member, an outer diameter of the second conductive member being smaller than an inner diameter of the first conductive member;

a contact section provided on an outer circumference surface of the second conductive member, formed to be larger than the outer diameter of the second conductive member, and including a conductor configured to contact an inner surface of the first conductive member; and

a second insulating member which includes: a proximal end portion which has an outer circumference surface and an inner circumference surface, the outer circumference surface of the proximal end portion extends inside a distal end of the first conductive member and is fixed to the distal end of the first conductive member, the inner circumference surface of the proximal end portion forming a space where the contact section is configured to move; and a distal end portion in which an opening section is opened to communicate with the space and through which the second conductive member is capable of protruding and retracting via the opening section, the distal end portion being formed at a distal end surface of the distal end portion, and

wherein the manipulation section comprises:

a manipulation main body section fixed to a proximal end of the first insulating member, and

a handle member attached to the manipulation main body section to be movable with respect to the manipulation main body section and to advance and retract the second conductive member with respect to the first conductive member; and

wherein the second insulating member is positioned between the contact section and the first conductive member in a state in which the second conductive member is protruded from the opening section of the second insulating member.

2. The incision instrument according to claim 1 , wherein the second conductive member is reciprocally movable between a storage position at which a distal end of the second conductive member is disposed in the second insulating member and an exposure position at which the second conductive member is exposed outside the second insulating member.

3. The incision instrument according to claim 2 , wherein the manipulation section has a connector configured to apply a high frequency current to the second conductive member,

the contact section is configured to be separated from the first conductive member in a state in which the second conductive member is positioned at the exposure position and is configured to come in contact with the first conductive member in a state in which the second conductive member is positioned at the storage position such that the second conductive member and the first conductive member are in a conduction state, and

the first conductive member is configured to be applied a high frequency current from the second conductive member via the contact section only when the contact section is in contact with the first conductive member.

4. The incision instrument according to claim 3 , wherein the manipulation section has a stopper member configured to fix the second conductive member to the first conductive member in a state in which the contact section and the first conductive member are in contact with each other.

5. The incision instrument according to claim 1 ,

wherein an exterior dimension of the second insulating member in a radial direction of the first conductive member is larger than an exterior dimension of the first conductive member in the radial direction of the first conductive member.

6. The incision instrument according to claim 1 , wherein, along a longitudinal axis, a length of the contact section is shorter than a length of the second insulating member.

7. An incision instrument comprising:

an insertion section that is configured to be inserted into a body; and

a manipulation section provided at a proximal end of the insertion section;

wherein the insertion section comprises:

a first insulating member which has an elongated tubular shape, and

an incision section inserted within the first insulating member;

wherein the incision section comprises:

a first conductive member which has a tubular tapered section that has an inner surface that is inclined to form a conical shape such that an inner diameter of the inner surface at a distal side is larger than an inner diameter of the inner surface at a proximal side, the first conductive member having conductivity;

a second conductive member disposed so as to movable inside the first conductive member along a longitudinal axis of the first conductive member, an outer diameter of the second conductive member being smaller than an inner diameter of the first conductive member;

a contact section provided on an outer circumference surface of the second conductive member, formed to be larger than the outer diameter of the second conductive member, and a proximal end of the contact section has a conical-shaped conductor configured to contact an inner surface of the tapered section of the first conductive member; and

a second insulating member which includes: a proximal end portion which has an outer circumference surface and an inner circumference surface, the outer circumference surface of the proximal end portion extends inside a distal end of the first conductive member and is fixed to the distal end of the first conductive member, the inner circumference surface of the proximal end portion forming a space where the contact section is configured to move; and a distal end portion in which an opening section is opened to communicate with the space and through which the second conductive member is capable of protruding and retracting via the opening section, the distal end portion being formed at a distal end surface of the distal end portion, and

wherein the manipulation section comprises:

a manipulation main body section fixed to a proximal end of the first insulating member, and

a handle member attached to the manipulation main body section to be movable with respect to the manipulation main body section and to advance and retract the second conductive member with respect to the first conductive member; and

wherein the second insulating member is positioned between the contact section and the first conductive member in a state in which the second conductive member is protruded from the opening section of the second insulating member.