PLASMA IRRADIATION APPARATUS AND DISTAL DEVICE

1 . A plasma irradiation apparatus, comprising:

a gas guide channel having an inlet port for introducing a gas, an outlet port for discharging the gas and a flow path located between the inlet port and the outlet port such that the gas introduced from the inlet port flows to the outlet port through an inner space of the flow path; and

a creeping discharge section having a dielectric layer, a discharge electrode and a ground electrode opposed to the discharge electrode with the dielectric layer interposed between the discharge electrode and the ground electrode, the creeping discharge section being disposed such that one of the discharge electrode and the ground electrode faces the flow path directly or via another member and being configured to generate creeping discharge in the flow path by the application of a periodically changing voltage to the discharge electrode,

wherein at least a part of the ground electrode is arranged closer to the outlet port than the discharge electrode.

2 . The plasma irradiation apparatus according to claim 1 ,

wherein the gas guide channel has the outlet port on one side thereof in a first direction and the inlet port on the other side thereof in the first direction,

wherein the flow path includes: a first flow passage extending along the first direction; and a second flow passage disposed at a location downstream of the first flow passage and closer to the outlet port than the first flow passage in the first direction and having a width narrower than that of the first flow passage.

3 . The plasma irradiation apparatus according to claim 2 ,

wherein at least a part of the ground electrode is situated in an arrangement area of the second flow passage in the first direction.

4 . The plasma irradiation apparatus according to claim 3 ,

wherein the discharge electrode is situated only in an arrangement area of the first flow passage in the first direction.

5 . The plasma irradiation apparatus according to claim 2 ,

wherein the discharge electrode faces the flow path directly or via another member, and

wherein, in a plane direction perpendicular to the first direction, an arrangement area of the discharge electrode is displaced from an opening area of the outlet port.

6 . The plasma irradiation apparatus according to claim 1 ,

wherein a width of the discharge electrode is narrower than a width of the ground electrode.

7 . A distal device, comprising:

an acting member having an acting portion that acts on biological tissue; and

the plasma irradiation apparatus according to claim 1 ,

wherein the gas guide channel is disposed to emit the gas from the outlet port toward the acting portion.

8 . The distal device according to claim 7 , comprising:

a drive section that drives the acting member;

wherein the drive section is an ultrasonic vibration section that generates ultrasonic vibration, and

wherein the acting member is configured to, by transmission of the ultrasonic vibration from the ultrasonic vibration section to the acting member, allow the acting portion to vibrate and thereby perform incision action, ablation action or hemostasis action on the biological tissue.

9 . The distal device according to claim 7 , comprising:

a drive section that drives the acting member;

wherein the drive section is a high-frequency current supply section that supplies a high-frequency current, and

wherein the acting member is configured to, by flow of the high-frequency current from the high-frequency current supply section through the acting member, allow the acting portion to perform incision action, ablation action or hemostasis action on the biological tissue.

10 . The distal device according to claim 7 ,

wherein the acting member, or an assembly member integrally assembled with the acting member, serves as the ground electrode.

11 . A distal device, comprising:

an acting member having an acting portion that acts on biological tissue;

a gas guide channel having an inlet port for introducing a gas, an outlet port for discharging the gas and a flow path located between the inlet port and the outlet port such that the gas is introduced from the inlet port and flows to the outlet port through an inner space of the flow path; and

a creeping discharge section having a dielectric layer, a discharge electrode and a ground electrode opposed to the discharge electrode with the dielectric layer interposed between the discharge electrode and the ground electrode, the creeping discharge section being disposed such that one of the discharge electrode and the ground electrode faces the flow path directly or via another member and being configured to generate creeping discharge in the flow path by the application of a periodically changing voltage to the discharge electrode,

the gas guide channel being disposed to emit the gas from the outlet port toward the acting portion,

wherein at least a part of the ground electrode is arranged closer to the outlet port than the discharge electrode, and

wherein the acting member, or an assembly member integrally assembled with the acting member, serves as the ground electrode.

12 . The distal device according to claim 11 , comprising:

a drive section that drives the acting member;

wherein the drive section is an ultrasonic vibration section that generates ultrasonic vibration, and

wherein the acting member is configured to, by transmission of the ultrasonic vibration from the ultrasonic vibration section to the acting member, allow the acting portion to vibrate and thereby perform incision action, ablation action or hemostasis action on the biological tissue.

13 . The distal device according to claim 11 , comprising:

a drive section that drives the acting member;

wherein the drive section is a high-frequency current supply section that supplies a high-frequency current, and

wherein the acting member is configured to, by flow of the high-frequency current from the high-frequency current supply section through the acting member, allow the acting portion to perform incision action, ablation action or hemostasis action on the biological tissue.