JP7386135B2 - Plasma irradiation device - Google Patents

Description

The present invention relates to a plasma irradiation device.

Patent Document 1 discloses a plasma surface treatment apparatus that performs creeping discharge type plasma discharge. In this device, a flow path for plasma generation gas is provided in the reaction part structure, and a creeping discharge electrode is arranged on the wall surface of this flow path. The creeping discharge electrode is composed of a discharge electrode arranged on a side surface in the direction in which the plasma generating gas moves, and an induction electrode facing the discharge electrode with a dielectric interposed therebetween.

Japanese Patent Application Publication No. 2005-50723

In a creeping discharge type plasma irradiation device, the creeping discharge part is configured such that one of the discharge electrode or the ground electrode faces the space in the flow channel directly or through another member, but the gas flowing through the flow channel is not necessarily It was not the case that it was efficiently supplied to the creeping discharge section side. In other words, depending on the way the gas flows, a large amount of gas may escape to the side of the flow path that is far from the creeping discharge part, and in such cases, there is a risk that plasma discharge will not be performed efficiently. was there.

The present invention has been made to solve at least part of the above-mentioned problems, and is capable of performing creeping discharge while efficiently supplying gas to the creeping discharge part in a plasma irradiation apparatus equipped with a creeping discharge part. The purpose is to provide technology.

The plasma irradiation device, which is one of the present invention,
It has an inlet for introducing gas, an outlet for discharging gas, and a flow path provided between the inlet and the outlet, and the gas introduced from the inlet side is passed through the flow path. a gas guide path for flowing the gas through the inner space to the outlet;
It has a dielectric layer, and a discharge electrode and a ground electrode that are arranged opposite to each other with the dielectric layer interposed therebetween, and one of the discharge electrode or the ground electrode directly or through another member is connected to the flow. a creeping discharge part that faces the space in the channel and generates a creeping discharge in the channel in response to a periodically changing voltage being applied to the discharge electrode;
A plasma irradiation device comprising:
The flow path is arranged to flow gas along the first direction at least in a region where the creeping discharge portion is provided,
In a second direction perpendicular to the first direction, the creeping discharge part is arranged on one side of the space,
The inner circumferential surface of the flow path in a cut plane cut in a direction perpendicular to the first direction at the position of the creeping discharge portion is closer to the first surface disposed on the one side of the space in the second direction. The second surface disposed on the other side is narrower, and the third and fourth surfaces disposed on both sides of the space in a third direction orthogonal to the first direction and the second direction are narrower. The interval in the third direction becomes narrower toward the second surface in at least a partial region in the second direction.

The plasma irradiation device described above suppresses the amount of gas escaping to the other side in the second direction (the side opposite to the creeping discharge part) when the gas flows in the first direction in the flow path, and The amount of gas flowing through the discharge part side can be increased. Therefore, gas is easily supplied to the vicinity of the inner surface near the creeping discharge portion within the flow path, and creeping discharge is more likely to be performed more efficiently.

In the plasma irradiation device described above, in at least a part of the range from the inlet to the creeping discharge part, the inner circumferential surface of the flow path in the cut plane perpendicular to the first direction is closer to the second surface than to the first surface. The distance between the third surface and the fourth surface in the third direction may become narrower toward the second surface in at least a partial region in the second direction.
In this way, if the second surface side is narrower than the first surface side in at least a part of the range from the inlet to the creeping discharge part, the gas entering from the inlet will be narrower until it reaches the vicinity of the creeping discharge part. This makes it easier to be guided to one side in the second direction. Therefore, gas is more easily supplied to the vicinity of the inner surface near the creeping discharge portion, and creeping discharge is more likely to be performed efficiently.

In the plasma irradiation device described above, the first annular figure when the inner edge of the discharge port is projected onto a virtual plane perpendicular to the first direction is a cut surface cut in a direction perpendicular to the first direction at the position of the creeping discharge part. The positional relationship may be such that the inner circumferential surface of the flow path is arranged inside the second annular figure when projected onto a virtual plane.
With this configuration, the gas flowing in the first direction near the creeping discharge portion can easily flow smoothly toward the discharge port at a higher flow velocity. Therefore, the plasma generated in the creeping discharge portion can be more efficiently discharged from the discharge port.

In the above plasma irradiation device, the height of the opening of the outlet in the second direction may be smaller than the height of the opening of the inlet in the second direction, and the height of the opening of the outlet in the second direction may be smaller than the height of the opening of the inlet in the second direction. The space may have a height reduction part in which the height in the second direction gradually decreases.
With this configuration, the height reduction portion can restrict the flow of gas in the height direction, and the flow of gas on the discharge port side can be made faster. Therefore, the plasma generated in the creeping discharge portion can be more efficiently discharged.

In the above plasma irradiation device, the dielectric layer may include a first dielectric layer disposed on one side of the space in the second direction and a second dielectric layer disposed on the other side of the space. good. Furthermore, the discharge electrode and the ground electrode may be arranged to face each other with a part of the first dielectric layer interposed therebetween, and the thickness of the second dielectric layer is smaller than the thickness of the first dielectric layer in the second direction. The thickness in the second direction may be smaller.
In this plasma irradiation device, a first dielectric layer having a relatively large thickness can suppress the electrical adverse effects exerted on the outside by the discharge electrode, and a second dielectric layer having a relatively small influence on creeping discharge can be suppressed. Since the thickness is relatively small, the size can be reduced. Therefore, the plasma irradiation device described above can achieve both the effect of suppressing the negative electrical influence on the outside and the effect of reducing the size.

According to the present invention, creeping discharge can be performed while efficiently supplying gas to the creeping discharge section side.

FIG. 1 is a schematic diagram schematically showing a tip device and a surgical apparatus including a plasma irradiation apparatus according to a first embodiment. FIG. 2 is an enlarged view conceptually showing a portion of the tip device of FIG. 1 in the vicinity of the action section. FIG. 3 is a perspective view conceptually showing a structure constituting the plasma irradiation apparatus of the first embodiment. FIG. 4 is an exploded perspective view conceptually showing a configuration in which the structure shown in FIG. 3 is divided into three parts. FIG. 5 is a cross-sectional view schematically showing a cross-sectional configuration of a cut surface of the structure constituting the plasma irradiation device of the first embodiment, cut at the center position in the third direction (width direction) in a direction perpendicular to the third direction. It is a schematic diagram. FIG. 6 schematically shows a cross-sectional configuration of a cut surface obtained by cutting the structure constituting the plasma irradiation device of the first embodiment at the center position in the second direction (thickness direction) in a direction perpendicular to the second direction. It is a cross-sectional schematic diagram. FIG. 7 shows a cross-sectional configuration of a cut surface obtained by cutting the structure constituting the plasma irradiation device of the first embodiment at the AA position (position of the creeping discharge part) in FIG. 6 in a direction perpendicular to the first direction. FIG. 2 is a schematic cross-sectional view; FIG. 8 schematically shows a cross-sectional configuration of a cut surface obtained by cutting the structure constituting the plasma irradiation device of the first embodiment at the BB position (near the inlet) in FIG. 6 in a direction perpendicular to the first direction. It is a cross-sectional schematic diagram shown in FIG. FIG. 9 schematically shows a cross-sectional configuration of a cut surface obtained by cutting the structure constituting the plasma irradiation device of the first embodiment at the CC position (near the introduction port) in FIG. 6 in a direction perpendicular to the first direction. It is a cross-sectional schematic diagram shown in FIG. FIG. 10 shows the first annular figure when the inner edge of the discharge port is projected onto a virtual plane perpendicular to the first direction, and the flow at a cut plane taken in the direction perpendicular to the first direction at the position of the creeping discharge part. It is an explanatory view showing a second annular figure when the inner circumferential surface of the road is projected onto the virtual plane. FIG. 11 is a cross-sectional view schematically showing a cross-sectional configuration of a cut surface of a structure constituting the plasma irradiation device of the second embodiment, cut at the center position in the third direction (width direction) in a direction perpendicular to the third direction. It is a schematic diagram. FIG. 12 is an exploded perspective view conceptually showing a configuration in which the structure constituting the plasma irradiation apparatus of the second embodiment is divided into three parts. FIG. 13 is a perspective view conceptually showing a structure constituting the plasma irradiation apparatus of the second embodiment. FIG. 14 is an explanatory diagram showing an example in which a plasma irradiation apparatus similar to that of the first embodiment is applied to a plasma irradiation system different from that of FIG. 1.

<First embodiment>
1-1. Overview of Surgical Apparatus The surgical apparatus 1 shown in FIG. 1 is configured as a treatment apparatus that can perform incision, ablation, or hemostasis on a living tissue to be treated. The surgical apparatus 1 supplies gas to the tip device 3, a control device 5 that is a device that controls the ultrasonic vibrating section 12 (drive section), and a gas guide path 30 (FIG. 5) in the tip device 3. and a power supply device 9 capable of applying voltage to the plasma irradiation device 20.

The control device 5 is a device that provides an electric signal to the ultrasonic vibrating section 12 to generate ultrasonic vibrations. The control device 5 is configured to be able to give an electrical signal to the ultrasonic vibrating section 12 via a flexible signal cable (not shown) interposed between the tip device 3 and the control device 5 .

The gas supply device 7 is a device that supplies an inert gas (hereinafter also simply referred to as gas) such as helium gas or argon gas. For example, the gas supply device 7 supplies an inert gas to a gas guide path 30 (described later) via a flexible ventilation member (not shown in FIG. 1) interposed between the tip device 3 and the gas supply device 7. supply The gas supply device 7 includes, for example, a regulator that reduces the pressure of high-pressure gas supplied from a cylinder or the like, and a control section that controls the flow rate.

The power supply device 9 is a device that supplies power to the high frequency voltage generation circuit 11, and is a circuit including a step-up transformer and the like. The high-frequency voltage generating circuit 11 is a device that applies a desired voltage between a discharge electrode 42 (FIG. 5) and a ground electrode 44 (FIG. 5), which will be described later. An alternating current voltage of a predetermined frequency is applied between the ground electrode 42 and the ground electrode 44 . The high-frequency voltage generation circuit 11 may employ various known circuits as long as they can generate a high voltage (for example, a high voltage with an amplitude of 0.5 kV to 10 kV) at a high frequency (for example, about 20 kHz to 300 kHz). It is possible. Note that the frequency of the high voltage generated by the high frequency voltage generation circuit 11 may be fixed to a constant value or may be varied. Further, the voltage applied between the ground electrode 44 and the discharge electrode 42 by the high-frequency voltage generation circuit 11 may be a voltage that changes periodically, may be a sinusoidal alternating current voltage, or may be a non-sinusoidal voltage ( For example, it may be an alternating current voltage with a rectangular wave, a triangular wave, etc.

In FIG. 1, the tip device 3 and the surgical apparatus 1 are illustrated in which the high frequency voltage generation circuit 11 is provided inside the case body 14, but the high frequency voltage generation circuit 11 is provided outside the case body 14 (for example, the tip device 3).

The tip device 3 is a device that is held and used by an operator who performs surgery, and mainly includes a case body 14, a gripping instrument 15, a plasma irradiation device 20, an ultrasonic vibrating section 12, and the like. The case body 14, the gripping device 15, the plasma irradiation device 20, and the ultrasonic vibrating unit 12 are integrally configured as a gripping unit that is gripped by the user, and is connected to an inert gas via a flexible member. and electricity are being supplied.

The case body 14 has a cylindrical shape and extends in a predetermined direction, and mainly includes a base portion 14B and a cylindrical extension portion 14A that is integrally formed with the base portion 14B and extends in a predetermined direction. The ultrasonic vibrator 12 and the like are housed inside the base 14B, and the plasma irradiation device 20 is fixed or integrated in the extension 14A.

The ultrasonic vibrator 12 is configured as a known ultrasonic vibrator, and is driven to generate ultrasonic vibrations when a predetermined electric signal is applied by the above-mentioned control device 5, and generates ultrasonic vibrations for the action member 16, which will be described later. It operates to transmit ultrasonic vibrations. The ultrasonic vibrating section 12 corresponds to an example of a driving section, and drives the action member 16 so that an action of incising, exfoliating, or thermal coagulation hemostasis of living tissue occurs near the action section 16A.

The grip part 60 is a part to be gripped by the user who uses the tip device 3, and is configured as a movable member displacement mechanism employing a known movable mechanism. The gripping part 60 includes a fixed gripping part 62 fixed to the base 14B of the case body 14 and integrated with the case body 14, and a shaft-shaped acting member 64 attached to the fixed gripping part 62 so as to be movable relative to the fixed gripping part 62. It is configured.

The grasping instrument 15 is an instrument that can be used to sandwich and grasp living tissue, and includes an action member 16 and an action member 64.

The acting member 16 is a shaft-shaped member, and is a member that includes an acting portion 16A that acts on living tissue on its distal end side. The action portion 16A is a portion near the tip of the action member 16 that functions as a fixed blade. The action member 16 has an action part 16A and a shaft part 16B that transmits vibrations applied from the ultrasonic vibration part 12 to the action part 16A, and the vibrations generated in the ultrasonic vibration part 12 are transmitted through the shaft part 16B. This is transmitted to the action section 16A, thereby causing the action section 16A to vibrate. The action member 16 operates so as to cause an incision action, a peeling action, or a hemostasis action on the living tissue by vibrating the action member 16A while the action part 16A approaches or is in contact with the living tissue.

The acting member 64 is a shaft-shaped member that functions as a movable member, and is a member that has an acting portion 64A that acts on living tissue on its distal end side (one end side). The action portion 64A is a portion that functions as a movable blade. The action member 64 includes a movable grip portion 64C near its rear end (other end). In the gripping instrument 15, the shaft-shaped acting member 64 is rotatable about a rotation axis Z near the tip of the extending portion 14A, and the acting portion 16A and the acting portion 64A are configured to be able to approach and separate from each other. ing. The gripping instrument 15 moves the action member 64 so that the action part 64A (movable blade) approaches the action part 16A (fixed blade) in response to an operation to bring the movable grip part 64C closer to the fixed grip part 62 side. rotates. Conversely, in response to an operation to separate the movable gripping part 64C from the fixed gripping part 62, the action member 64 rotates so that the action part 64A separates from the action part 16A.

The distal end device 3 configured in this manner can perform incision, ablation, and hemostasis on living tissue using ultrasonic vibration. For example, when living tissue is sandwiched between the action part 16A (fixed blade) and the action part 64A, the living tissue can be excised by transmitting ultrasonic vibrations to the action part 16A. Furthermore, hemostasis can also be achieved by bringing the action portion 16A, through which ultrasonic vibrations are transmitted, into contact with living tissue to generate frictional heat. It is also possible to perform the ablation treatment by holding the living tissue between the action portion 16A and the action portion 64A while applying or not applying ultrasonic vibration to the action member 16. In this way, the advanced device 3 enables incision, ablation, or thermal coagulation hemostasis using ultrasonic vibration, and can also perform minimally invasive hemostasis by irradiating low-temperature plasma from the plasma irradiation device 20, which will be described later. You can also do it.

1-2. Basic Configuration of Plasma Irradiation Apparatus As shown in FIG. 1, the plasma irradiation apparatus 20 is incorporated as a part of the tip device 3, and is configured as a device that generates a dielectric barrier discharge inside the tip device 3. In the example of FIG. 1, the plasma irradiation device 20 is fixed to the case body 14 in a configuration that is held by the holding portion 18. As shown in FIG. 2, the low temperature plasma P generated inside the plasma irradiation device 20 is irradiated to the vicinity of the action portion 16A provided at the tip of the action member 16. In addition, in FIG. 2, the position of the action member 64 when the action part 16A and the action part 64A contact is conceptually shown by the two-dot chain line.

As shown in FIG. 3, the plasma irradiation device 20 has a structure 20A configured in a predetermined three-dimensional shape (for example, plate-like and rectangular parallelepiped shape), and has a structure 20A formed at the longitudinal end of the structure 20A. The low-temperature plasma P is irradiated from the discharge port 34.

As conceptually shown in FIG. 4, the structure 20A includes a dielectric layer 53 provided at the center in the thickness direction, and a dielectric layer 54 provided on one side of the dielectric layer 53 in the thickness direction. ing. Further, in the structure 20A, a dielectric layer 51 and a dielectric layer 52 are provided on the other side of the dielectric layer 53 in the thickness direction. A discharge electrode 42 and a ground electrode 44 are embedded inside a dielectric region formed by the dielectric layer 51 and the dielectric layer 52. Although FIG. 4 conceptually shows a configuration in which the structure 20A is divided into three parts as an exploded perspective view, the actual configuration includes a dielectric layer 51, a dielectric layer 52, a dielectric layer 53, and a dielectric layer 52. Each layer 54 is constructed as part of an integral dielectric portion 50 (FIG. 7).

As shown in FIG. 5, the structure 20A includes a gas guide path 30 and a creeping discharge section 40.

The gas guide path 30 has an introduction port 32 for introducing gas, a discharge port 34 for releasing the gas, and a flow path 36 provided between the introduction port 32 and the discharge port 34. The discharge port 34 functions to discharge the gas that has flowed through the flow path 36 on the distal end side of the flow path 36 . The flow path 36 functions to flow gas toward the discharge port 34 arranged on the tip side, and is arranged so as to flow the gas along the first direction at least in the area where the creeping discharge section 40 is provided. . The gas guide path 30 introduces an inert gas supplied from the gas supply device 7 (FIG. 1) provided outside the tip device 3 through the pipe line 7A through the introduction port 32, and introduces the inert gas from the introduction port 32 side. This serves as a guide path for guiding the released gas to the discharge port 34 through the space within the flow path 36. In addition, in FIG. 5, the conduit 7A for supplying gas toward the introduction port 32 is conceptually shown by a two-dot chain line. The gas guide path 30 has a flow path configuration that releases gas from the discharge port 34 to the action section 16A (FIG. 2) side, and together with the gas, sends the low-temperature plasma P (FIG. 2) from the discharge port 34 to the action section 16A side. Functions to emit.

As shown in FIG. 5, in this specification, the direction in which the gas guide path 30 extends in the plasma irradiation device 20 is the first direction, and the thickness direction of the dielectric part 50 is the direction perpendicular to the first direction. The second direction is the third direction (FIG. 7), and the direction perpendicular to the first direction and the second direction is the third direction (FIG. 7). In the configuration of FIG. 5, the first direction is the longitudinal direction of the structure 20A in which the dielectric portion 50, the discharge electrode 42, and the ground electrode 44 are integrally provided. The lateral direction of the structure 20A in a cut plane (FIG. 7) obtained by cutting the structure 20A in a plane direction perpendicular to the first direction is the second direction, and the longitudinal direction of this cut plane is the third direction ( Figure 7). The third direction (FIG. 7) is the width direction of the structure 20A, and the second direction is the height or thickness direction of the structure 20A. In addition, in the following description, the discharge port 34 side is the front end side of the structure 20A in the first direction, and the inlet port 32 side is the rear end side of the structure 20A in the first direction.

As shown in FIG. 5, the structure 20A has a gas guide path 30 configured to flow gas along a predetermined direction (first direction), and a second direction perpendicular to the predetermined direction (first direction). The discharge electrode 42, the ground electrode 44, and the dielectric portion 50 are laminated in such a configuration that the lamination direction is the lamination direction.

The creeping discharge section 40 includes a dielectric layer 51, and a discharge electrode 42 and a ground electrode 44 that are arranged to face each other with the dielectric layer 51 interposed therebetween. The creeping discharge section 40 functions to generate an electric field within the gas guide path 30 based on the potential difference between the discharge electrode 42 and the ground electrode 44 to generate a low-temperature plasma discharge by creeping discharge. Specifically, the creeping discharge section 40 maintains the potential of the ground electrode 44 at a constant reference potential (for example, 0V ground potential) and responds to the periodically changing voltage being applied to the discharge electrode 42. A creeping discharge is generated within the flow path 36 to generate low-temperature plasma.

The creeping discharge section 40 responds to a periodically changing voltage being applied to the discharge electrode 42 while one of the discharge electrode 42 or the ground electrode 44 faces the space of the flow path 36 directly or through another member. This is to generate creeping discharge within the flow path 36. Note that "a configuration in which one of the discharge electrode 42 or the ground electrode 44 directly faces the flow path 36" means that one of the discharge electrode 42 or the ground electrode 44 is exposed to the space inside the flow path 36, and the one is exposed to the space inside the flow path 36. This applies to structures that form part of the inner wall. Furthermore, "a configuration in which one of the discharge electrode 42 or the ground electrode 44 faces the flow path 36 via another member" means that one of the discharge electrode 42 or the ground electrode 44 is disposed at a position close to the flow path 36. This corresponds to a configuration in which both parts are partially or completely covered by another member. In this configuration using another member, the other member forms a part of the inner wall of the flow path, and the above-mentioned "one" main surface is arranged facing the flow path 36. Note that in the configuration shown in FIG. 5, the discharge electrode 42 corresponds to the above-mentioned "one side", and is "a configuration in which the discharge electrode 42 faces the flow path 36 through another member", but in FIG. A dielectric layer 52 corresponding to an example of the member is shown in an omitted form (see FIGS. 6 and 7).

1-3. Specific configuration of gas guide path and creeping discharge section As shown in FIG. 6, the flow path 36 constituting the gas guide path 30 has a space surrounded on both sides in the second direction (FIG. 5) and on both sides in the third direction. It is configured to continue in the first direction. The flow path 36 includes a first flow path 36A extending along the first direction, a second flow path 36B provided on the downstream side of the first flow path 36A, and a third flow path 36B provided on the upstream side of the first flow path 36A. A flow path 36C is provided. The first flow path 36A is provided in the first region AR1 in the first direction in the structure 20A. The second flow path 36B is provided in the second region AR2 in the first direction in the structure 20A, and includes a reduced width flow path 37A and a constant flow path 37B. The third flow path 36C is provided in the third region AR3 in the first direction in the structure 20A, and includes an enlarged flow path 38A and a constant flow path 38B. In FIG. 6, the range where the first flow path 36A is provided in the first direction is represented as a first region AR1, the range where the second flow path 36B is provided in the first direction is represented as a second region AR2, and the range where the first flow path 36A is provided in the first direction is represented as a second region AR2. The range in which the third flow path 36C is provided in the direction is expressed as a third region AR3.

In the first flow path 36A shown in FIG. 6, the shape of its inner wall surface in a cut plane perpendicular to the first direction is approximately constant (FIG. 7) at any position in the first region AR1 in the first direction. has been done. That is, the details of the inner wall surface of the first flow path 36A will be described later.

As shown in FIG. 6, the second flow path 36B has a narrower width than the first flow path 36A between the first flow path 36A and the discharge port 34. In the second flow path 36B, the reduced width flow path 37A is provided over a partial area AR21 of the second area AR2 in the first direction. In the width-reduced flow path 37A, the width of the inner wall surface becomes gradually narrower as it approaches the discharge port 34, and the size of its own inner wall surface in a cut plane perpendicular to the first direction gradually decreases as it approaches the discharge port 34. It's getting smaller. The height of the reduced width channel 37A is constant over the entire range of the region AR21. The constant flow path 37B is provided over a partial area AR22 of the second area AR2 in the first direction, and at any position in the partial area AR22 in the first direction, the constant flow path 37B is provided on its own inner wall surface in a cut plane perpendicular to the first direction. The shape is approximately constant (FIG. 9). Note that details of the inner wall surface of the constant flow path 37B will be described later.

As shown in FIG. 6, the third flow path 36C has a narrower width than the first flow path 36A between the introduction port 32 and the first flow path 36A. In the third flow path 36C, the widened flow path 38A is provided in the first direction over a partial area AR31 of the third area AR3, and the width of the inner wall surface gradually increases as it approaches the first flow path 36A. The size of its own inner wall surface in a cut plane perpendicular to the direction gradually increases as it approaches the first flow path 36A. The height of the widened channel 38A is constant over the entire range of the region AR31. The constant flow path 38B is provided over a partial area AR32 of the third area AR3 in the first direction, and at any position in the partial area AR32 in the first direction, the constant flow path 38B is provided on its own inner wall surface in a cut plane orthogonal to the first direction. The shape is approximately constant (FIG. 8). Note that details of the inner wall surface of the constant flow path 38B will be described later.

With respect to the flow path 36 configured in this way, the ground electrode 44 extends linearly in the first direction along the flow path 36, and is disposed in a predetermined area in the first direction. A portion of the ground electrode 44 on its own tip side is arranged closer to the discharge port 34 than the discharge electrode 42 is. A part of the ground electrode 44 is located in the arrangement area AR2 of the second flow path 36B in the first direction, and in the example of FIG. It is located on the distal end side of the flow path 37B (rear end), and is located in the arrangement region AR22 of the constant flow path 37B in the first direction. The rear end of the ground electrode 44 is located on the rear end side of the first flow path 36A, the rear end of the discharge electrode 42, and the rear end of the discharge electrode 42. . At least a part of the ground electrode 44 (all of the ground electrode in FIG. 6) is located within the arrangement region AR1 of the first flow path 36A in the third direction. More specifically, the ground electrode 44 has at least a part of itself (a part of itself in FIG. 6) located within the arrangement region AR4 of the constant flow path 37B in the third direction, and At least a part of itself (a part of itself in FIG. 6) is located within the formation region of.

As shown in FIG. 6, the discharge electrode 42 includes a plurality of (specifically, three) linear electrode parts 42A configured in a straight line, and these linear electrode parts 42A are arranged along the flow path 36. The linear electrode portions 42A extend linearly in the first direction, and each linear electrode portion 42A functions as a linear electrode. Each linear electrode portion 42A is made of a conductor having a constant width and a constant thickness, and is arranged in a predetermined area in the first direction. The plurality of linear electrode portions 42A are connected at their rear ends, electrically connected to each other, and have the same potential. The discharge electrode 42 is located so as to straddle the arrangement region of the first flow path 36A (first region AR1) and the arrangement region of the third flow path 36C (third region AR3) in the first direction. That is, the distal end of the discharge electrode 42 is located on the rear end side of the first flow path 36A, and the rear end of the discharge electrode 42 is located on the rear end side (specifically, , between the tip and rear end of the third flow path 36C). Further, the width (length in the third direction) of each linear electrode portion 42A is smaller than the width (length in the third direction) of the ground electrode 44. The entire discharge electrode 42 falls within the arrangement region AR5 of the ground electrode 44 in the third direction.

As shown in FIG. 7, the dielectric section 50 includes a dielectric layer 51, a dielectric layer 52, a dielectric layer 53, and a dielectric layer 54, and has a hollow shape as a whole.

The dielectric layer 51 is arranged on one side in the second direction (thickness direction) with respect to the space of the flow path 36, and is configured such that the ground electrode 44 is embedded therein. The dielectric layer 52 is a ceramic protective layer configured to cover the discharge electrode 42 using a ceramic material, and is arranged so as to cover the discharge electrode 42 on the flow path space side of the dielectric layer 51 . The dielectric layer 51 and the dielectric layer 52 constitute an inner wall portion of the flow path 36 on one side in the second direction. In the example of FIG. 7, the discharge electrode 42 and the ground electrode 44 face each other with the dielectric layer 51 in between. The discharge electrode 42 faces the flow path 36 via the dielectric layer 52, and is disposed within the dielectric portion 50 at a first position in the second direction and with a first thickness. The ground electrode 44 is disposed within the dielectric portion 50 at a second position in the second direction and has a second thickness, and is provided on the opposite side of the discharge electrode 42 from the flow path 36 . It is further away from the flow path 36 than the With such a configuration, the creeping discharge section 40 is arranged on one side in the second direction of the space within the flow path 36.

The dielectric layer 54 is disposed on the other side in the second direction (thickness direction) of the space of the flow path 36 and constitutes an inner wall portion of the flow path 36 on the other side in the second direction. The dielectric layer 53 is disposed between the dielectric layer 51 and the dielectric layer 54 in the second direction, and forms a side wall portion on one side in the third direction and a side wall portion on the other side in the third direction in the flow path 36. . In this way, the flow path 36 is defined by the dielectric layer 51 , the dielectric layer 52 , the dielectric layer 53 , and the dielectric layer 54 .

As the material of the dielectric layer 51, the dielectric layer 52, the dielectric layer 53, and the dielectric layer 54, ceramics such as alumina, glass materials, and resin materials can be suitably used. Note that by using alumina, which has high mechanical strength, as the dielectric material, it becomes easier to reduce the size of the creeping discharge section 40.

1-4. Detailed Configuration of Flow Path As shown in FIG. 7, the inner circumferential surface 110 of the flow path 36 at the cut plane in the direction perpendicular to the first direction (FIG. 6) at the position of the creeping discharge portion 40 in the structure 20A is The second surface 112 disposed on the other side in the second direction is narrower than the first surface 111 disposed on one side in the second direction of the space 102 of 36. One side in the second direction is the creeping discharge part 40 side with respect to the space 102 in the second direction, and the other side in the second direction is the side opposite to the creeping discharge part 40 with respect to the space 102 in the second direction. It is. The inner circumferential surface 110 in the cut plane has a third surface 113 and a fourth surface 114 disposed on both sides of the space 102 of the flow path 36 in the third direction. It becomes narrower toward the second surface 112 side in at least a partial region. In the example of FIG. 7, the inner peripheral surface 110 of the structure 20A is configured to have a trapezoidal shape, and the outer peripheral surface 120 of the structure 20A is also configured to have a trapezoidal shape in the cut plane. ing. In addition, in the example of FIG. 7, the distance in the third direction between the third surface 113 and the fourth surface 114 in the above-mentioned cut surface is such that the distance between the third surface 113 and the fourth surface 114 in the second direction extends toward the second surface 112 in the entire area of the inner circumferential surface 110 in the second direction. It's getting narrower.

Specifically, a cut is made in a direction perpendicular to the first direction at any position in the overlapping region AR11 (FIG. 6) where the discharge electrode 42 and the ground electrode 44 are arranged in the first direction (FIG. 6). The inner peripheral surface 110 of the flow path 36 has a trapezoidal shape as shown in FIG. At any position in the overlapping region AR11 (FIG. 6), the inner circumferential surface 110 at the cut plane (the cut plane in the direction orthogonal to the first direction) is smaller than the first plane 111. It's narrower. That is, in the cut plane in the overlapping region AR11 (FIG. 6), the width Za2 of the second surface 112 in the third direction is smaller than the width Za1 of the first surface 111 in the third direction. The width Za2 of the second surface 112 in the third direction is larger than the size of the third surface 113 in the second direction (height Ya2 in the example of FIG. 7), and the size of the fourth surface 114 in the second direction ( In the example of FIG. 7, it is larger than the height Ya2). Furthermore, at any position in the overlapping region AR11 (FIG. 6), the inner circumferential surface 110 in the cut plane has at least a partial region where the interval in the third direction between the third surface 113 and the fourth surface 114 is in the second direction. It becomes narrower toward the second surface 112 side. Specifically, at any position in the overlapping region AR11 (FIG. 6), in the entire region where the third surface 113 and the fourth surface 114 are provided, in the third direction of the third surface 113 and the fourth surface 114. The interval becomes narrower toward the second surface 112 side.

Furthermore, at any position in the overlapping region AR11 (FIG. 6), as shown in FIG. The second outer surface 122 disposed on the other side in the second direction is narrower than the first outer surface 121 disposed on the other side in the second direction. Further, the outer circumferential surface 120 at the above-mentioned cut plane has at least a partial area (FIG. 7 In this case, the entire region of the structure 20A in the second direction) becomes narrower toward the second outer surface 122 side. In this way, the second outer surface 122 side is made smaller and lighter.

Further, as shown in FIG. 7, at least in the overlapping region AR11 (FIG. 6), the dielectric portion 50 (dielectric layer) of the structure 20A is a first dielectric layer disposed on one side in the second direction with respect to the space 102. The second dielectric layer (dielectric layer 54) is arranged on the other side in the second direction with respect to the space 102. The discharge electrode 42 and the ground electrode 44 are arranged to face each other with the first dielectric layer (specifically, a part of the dielectric layer 51) interposed therebetween. In such a configuration, the thickness Ta1 of the second dielectric layer (dielectric layer 54) in the second direction is greater than the thickness Ta1 of the first dielectric layer (dielectric layer 51 and dielectric layer 52) in the second direction. Ta2 is smaller. Note that the thickness Ta1 is the thickness in the second direction of the portion of the first dielectric layer (dielectric layer 51 and dielectric layer 52) that faces the space 102 (the portion where the first surface 111 is provided). is the thickness at the smallest position. The thickness Ta2 is the thickness at the smallest thickness in the part of the second dielectric layer (dielectric layer 54) facing the space 102 (the part where the second surface 112 is provided). be.

FIG. 8 shows a cut surface taken in the direction orthogonal to the first direction near the inlet 32 (FIG. 6) in the constant flow path 38B (FIG. 6). As shown in FIG. 8, even in at least a partial range from the inlet 32 (FIG. 6) to the creeping discharge section 40 (FIG. 6), the flow path in the cut plane perpendicular to the first direction (FIG. 6) The second surface 112 of the inner circumferential surface 110 of 36 is narrower than the first surface 111. Specifically, at any position of the constant flow path 38B (FIG. 6), the inner circumferential surface 110 of the flow path 36 at the cut surface (the cut surface in the direction perpendicular to the first direction) is as shown in FIG. It has a trapezoidal shape, and the second surface 112 is narrower than the first surface 111. That is, even in this cut surface, the width Zb2 of the second surface 112 in the third direction is smaller than the width Zb1 of the first surface 111 in the third direction. The width Zb2 of the second surface 112 in the third direction is larger than the width (height Yb2 in the example of FIG. 8) of the third surface 113 in the second direction in the cut plane of FIG. It is larger than the size in two directions (height Yb2 in the example of FIG. 8). Furthermore, in the cut plane at any position of the constant flow path 38B (FIG. 6), the inner circumferential surface 110 has at least a partial region where the interval in the third direction between the third surface 113 and the fourth surface 114 is in the second direction. (Specifically, the entire area where the third surface 113 and the fourth surface 114 are provided) becomes narrower toward the second surface 112 side.

Furthermore, at any position of the constant flow path 38B (FIG. 6) on the cut surface (the cut surface in the direction perpendicular to the first direction), the outer circumferential surface 120 of the structure 20A is on one side of the space 102 in the second direction. The second outer surface 122 disposed on the other side in the second direction is narrower than the first outer surface 121 disposed. Furthermore, the outer circumferential surface 120 at the cut plane has a distance in the third direction between the third outer surface 123 and the fourth outer surface 124 disposed on both sides of the space 102 in the third direction at least in a partial region in the second direction (FIG. In this case, the entire region of the structure 20A in the second direction) becomes narrower toward the second outer surface 122 side. In this way, the second outer surface 122 side is made smaller and lighter.

FIG. 9 shows a cross section cut in the direction orthogonal to the first direction near the discharge port 34 (FIG. 6) in the constant flow path 37B (FIG. 6). As shown in FIG. 9, even in at least a partial range from the discharge port 34 (FIG. 6) to the creeping discharge section 40 (FIG. 6), the flow path in the cut plane perpendicular to the first direction (FIG. 6) The second surface 112 of the inner circumferential surface 110 of 36 is narrower than the first surface 111. Specifically, at any position of the constant flow path 37B (FIG. 6), the inner circumferential surface 110 of the flow path 36 at the cut surface (the cut surface in the direction perpendicular to the first direction) is as shown in FIG. It has a trapezoidal shape, and the second surface 112 is narrower than the first surface 111. That is, even in this cut surface, the width Zc2 of the second surface 112 in the third direction is smaller than the width Zc1 of the first surface 111 in the third direction. The width Zc2 of the second surface 112 in the third direction is larger than the width (height Yc2 in the example of FIG. 9) of the third surface 113 in the second direction in the cut plane of FIG. It is larger than the size in two directions (height Yc2 in the example of FIG. 9). Furthermore, in the cut plane at any position of the constant flow path 37B (FIG. 6), the inner circumferential surface 110 has at least a partial region where the interval in the third direction between the third surface 113 and the fourth surface 114 is in the second direction. (Specifically, the entire area where the third surface 113 and the fourth surface 114 are provided) becomes narrower toward the second surface 112 side.

Furthermore, at any position of the constant flow path 37B (FIG. 6) on the cut surface (the cut surface in the direction orthogonal to the first direction), the outer circumferential surface 120 of the structure 20A is on one side of the space 102 in the second direction. The second outer surface 122 disposed on the other side in the second direction is narrower than the first outer surface 121 disposed. Furthermore, the outer circumferential surface 120 at the cut plane has a distance in the third direction between the third outer surface 123 and the fourth outer surface 124 disposed on both sides of the space 102 in the third direction at least in a partial region in the second direction (FIG. In this case, the entire region of the structure 20A in the second direction) becomes narrower toward the second outer surface 122 side. In this way, the second outer surface 122 side is made smaller and lighter.

FIG. 10 shows two points of the first annular figure when the inner edge (inner peripheral surface 110 shown in FIG. 9) of the discharge port 34 (FIG. 6) is projected onto a virtual plane orthogonal to the first direction (FIG. 6). It is shown in dashed lines and labeled 34Z. Furthermore, when the inner circumferential surface 110 of the flow path 36 at the cut plane cut in the direction perpendicular to the first direction at the position of the creeping discharge portion 40 is projected onto the virtual plane, a second annular figure is shown by a thick solid line. and is designated by the reference numeral 40Z. In the plasma irradiation device 20, when projected onto a virtual plane as shown in FIG. 10, the positional relationship is such that the majority area (preferably the entire area) of the first annular figure 34Z is arranged inside the second annular figure 40Z. , the inner area of the first annular figure 34Z is smaller than the inner area of the second annular figure 40Z. In the example of FIG. 10, both end portions (slanted portions) 134C and 134D on both sides in a predetermined direction (longitudinal direction) of the first annular figure 34Z are opposite to each other in the predetermined direction (longitudinal direction) of the second annular figure 40Z in the predetermined direction. (direction) is arranged between the ends (slanted parts) 140C and 140D on both sides. Then, the ends 134A, 134B on both sides of the first annular figure 34Z in the orthogonal direction (short side direction) perpendicular to the predetermined direction are aligned in the orthogonal direction (short side direction) of the second annular figure 40Z in the orthogonal direction. direction) is arranged between the ends 140A and 140B on both sides.

1-5. Examples of Effects of the Present Configuration The plasma irradiation device 20 of the present configuration has gas that escapes to the other side in the second direction (the opposite side to the creeping discharge section 40) when gas flows in the first direction in the flow path 36. The flow rate of the gas flowing on one side in the second direction (the creeping discharge section 40 side) can be increased. Therefore, gas is easily supplied to the vicinity of the inner surface near the creeping discharge section 40 within the flow path 36, and the creeping discharge is more likely to be performed more efficiently.

In the plasma irradiation device 20, in at least a partial range (for example, the entire range) from the inlet 32 to the creeping discharge part 49, the inner circumferential surface 110 of the flow path 36 in the cut plane perpendicular to the first direction is The second surface 112 is narrower than the first surface 111. Then, the distance between the third surface 113 and the fourth surface 114 in the third direction is set to the second direction in at least a partial region in the second direction (for example, the entire region where the third surface 113 and the fourth surface 114 are provided). It becomes narrower toward the surface 112 side. In this way, if the second surface 112 side is narrower than the first surface 111 side in at least a part of the range from the inlet 32 to the creeping discharge part 40, the gas entering from the inlet 32 will cause the creeping discharge. By the time it reaches the vicinity of the portion 40, it becomes easier to be guided to one side in the second direction. Therefore, gas is more easily supplied to the vicinity of the inner surface near the creeping discharge section 40, and creeping discharge is more likely to be performed efficiently.

Furthermore, in the plasma irradiation device 20, the first annular figure 34Z when the inner edge of the discharge port 34 is projected onto a virtual plane perpendicular to the first direction is located in the direction perpendicular to the first direction at the position of the creeping discharge part 40. The inner circumferential surface 110 of the flow path 36 at the cut plane is positioned inside the second annular figure 40Z when projected onto the virtual plane. With this configuration, the gas flowing in the first direction near the creeping discharge portion 40 can easily flow toward the discharge port 34 at a higher flow velocity. Therefore, the plasma generated in the creeping discharge section 40 can be more efficiently discharged from the discharge port 34.

Further, the dielectric portion 50 (dielectric layer) is arranged between a first dielectric layer (dielectric layers 51 and 52) disposed on one side of the space 102 of the flow path 36 in the second direction and a space 102 of the flow path 36. and a second dielectric layer (dielectric layer 54) disposed on the other side of the dielectric layer. Furthermore, the discharge electrode 42 and the ground electrode 44 are arranged to face each other with a part of the first dielectric layer interposed therebetween, and the second dielectric layer is thicker than the thickness Ta1 of the first dielectric layer in the second direction. The thickness Ta2 in the second direction is smaller. This plasma irradiation device 20 can suppress the electrical adverse effects exerted on the outside by the discharge electrode 42 with the first dielectric layer having a relatively large thickness, and the second dielectric layer has a relatively small influence on creeping discharge. Due to the relatively small thickness of the layers, size reduction is achieved. Therefore, the plasma irradiation device 20 can achieve both the effect of suppressing the negative electrical influence on the outside and the effect of reducing the size.

<Second embodiment>
Next, the plasma irradiation device 220 of the second embodiment will be described with reference to FIG. 11 and the like.
The plasma irradiation device 220 of the second embodiment differs from the plasma irradiation device 20 of the first embodiment only in that the shape of the dielectric portion 50 (dielectric layer) is slightly changed and the shape of the flow path 36 is slightly changed. , and other points are the same as the plasma irradiation apparatus 20 of the first embodiment. Therefore, in the following description, the configuration related to the dielectric section 50 and the flow path 36 will be described in detail, and other points will be given the same reference numerals as each part of the plasma irradiation device 20, and detailed explanation will be omitted. do.

The plasma irradiation device 220 of the second embodiment shown in FIG. 11 etc. can be provided in place of the plasma irradiation device 20 in the surgical apparatus 1 and the tip device 3 shown in FIG. A tip device and a surgical apparatus may be configured with apparatus 220. The following description will be made on the premise that a plasma irradiation device 220 is applied in place of the plasma irradiation device 20 in the tip device 3 and surgical apparatus 1 of FIG. 1.

As shown in FIG. 11, in the plasma irradiation device 220, the height Ye2 of the opening of the discharge port 34 in the second direction is smaller than the height Yd2 of the opening of the inlet 32 in the second direction. Then, in at least a partial region of the flow path 36 (in FIG. 11, the entire region of the flow path 36 in the first direction), a height reduction portion where the height of the space 102 in the second direction gradually decreases toward the discharge port 34. It has 236. In the example of FIG. 11, the entire flow path 36 is configured as the height reduction section 236, but only a portion of the flow path 36 may be configured as the height reduction section. In this example, as shown in FIG. 12, the thickness (length in the second direction) of the third dielectric layer 53 gradually decreases as it approaches the tip side in the first direction (the discharge port 34 side shown in FIG. 11). ing. Note that in the configuration of FIG. 12, only the thickness of the third dielectric layer 53 is changed from the configuration of FIG. 4. As shown in FIG. 13, the thickness (length in the second direction) of the structure 20A also gradually decreases as it approaches the tip side in the first direction (discharge port 34 side), and the thickness (length in the second direction) of the structure 20A gradually decreases as it approaches the tip side in the first direction (discharge port 34 side). The thickness Ye1 (FIG. 11) of the tip portion (end portion on the discharge port 34 side in the first direction) is smaller than the thickness Yd1 (FIG. 11) of the portion (end portion on the inlet port 32 side in the first direction). It has become.

In the plasma irradiation device 220 of the second embodiment, the height Ye2 of the opening of the discharge port 34 in the second direction is smaller than the height Yd2 of the opening of the introduction port 32 in the second direction. At least a partial region of the flow path 36 has a height reduction portion 236 in which the height of the space 102 in the second direction gradually decreases toward the discharge port 34 . With this configuration, the height reduction portion 236 can restrict the flow of gas in the height direction, and the flow of gas on the discharge port 34 side can be further accelerated. Therefore, the plasma generated in the creeping discharge section 40 can be more efficiently discharged.

<Other embodiments>
The invention is not limited to the embodiments described above and illustrated in the drawings. For example, the features of the embodiments described above or below can be combined in any combination without contradicting each other. Furthermore, any feature of the embodiments described above or below may be omitted unless explicitly stated as essential. Furthermore, the embodiment described above may be modified as follows.

In the above-described embodiment, a configuration is illustrated in which a plasma irradiation device is incorporated into an advanced device capable of performing ultrasonic vibration, but a plasma irradiation device having any of the configurations described above is incorporated into an advanced device having other electrical functions. The configuration may be different. For example, the plasma irradiation device having any of the configurations described above may be incorporated into an electric scalpel having a structure and function different from those of the device 3 disclosed in FIG. 1. Alternatively, a plasma irradiation device having any of the above configurations may be incorporated into a tip device configured as a known surgical instrument (for example, forceps, etc.) that does not have an electrical function.

In the embodiment described above, an example of an advanced device in which a plasma irradiation device is incorporated is shown, but the plasma irradiation device may be incorporated in an advanced device different from the above embodiment, or may not be incorporated in an advanced device. Good too.
For example, a part of the configuration shown in FIG. 1 is omitted, and as shown in FIG. 14, a plasma irradiation system 301 is constructed with a configuration including a plasma irradiation device 20, a control device 5, a gas supply device 7, and a power supply device 9. You may. This plasma irradiation system 301 may be used as a surgical system or may be used for purposes other than surgery. In the example of FIG. 14, the tip device 303 includes the plasma irradiation device 20 and the case body 314 similar to the first embodiment, and the plasma irradiation device 20 is incorporated in the case body 314. This tip device 303 includes a case body 314, the plasma irradiation device 20, the high-frequency voltage generation circuit 11, and other parts that are integrated to form a gripping unit (a hand-held portion that is gripped by the user). In this case, the control device 5 may be provided with a function to perform other control instead of controlling the ultrasonic vibrating section 12.

In the second embodiment, the height reduction portion 236 in which the height of the space 102 in the second direction gradually decreases toward the discharge port 34 is provided in the flow path 36, but at least a partial area of the flow path ( For example, a height expanding portion may be provided in which the height of the channel space in the second direction gradually increases toward the discharge port in the entire region in the first direction.

In the embodiment described above, an example was shown in which the tip of the ground electrode 44 was provided on the tip side (on the discharge port 34 side in the first direction) than the tip of the discharge electrode 42. However, in any example of any embodiment, the tip of the ground electrode 44 may be provided on the rear end side (on the introduction port 32 side in the first direction) than the tip of the discharge electrode 42. Alternatively, in any example of any embodiment, the tip of the ground electrode 44 and the tip of the discharge electrode 42 may be the same in the first direction.

In the above embodiment, an example was shown in which the rear end portion of the ground electrode 44 was provided closer to the tip side (on the discharge port 34 side in the first direction) than the rear end portion of the discharge electrode 42 . However, in any example of any embodiment, the rear end portion of the ground electrode 44 may be provided on the rear end side (on the introduction port 32 side in the first direction) than the rear end portion of the discharge electrode 42. Alternatively, in any example of any embodiment, the rear end portion of the ground electrode 44 and the rear end portion of the discharge electrode 42 may be the same in the first direction.

In the specification, "acting on living tissue" means that the action member affects living tissue and performs at least one of incision, exfoliation, and hemostasis. The action members exemplified in the above-mentioned embodiments are merely examples, and as long as the action members can affect living tissue and perform at least one of incision, exfoliation, and hemostasis, embodiments other than those described above may be used. Various configurations can be adopted.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, and includes all modifications within the scope indicated by the claims or within the scope equivalent to the claims. is intended.

20, 220... Plasma irradiation device 30... Gas guide path 34... Outlet 36... Channel 40... Creeping discharge part 42... Discharge electrode 44... Ground electrode 50... Dielectric part (dielectric material layer)
51, 52...Dielectric layer (first dielectric layer)
54...Dielectric layer (second dielectric layer)
102... Space 110... Inner peripheral surface 111... First surface 112... Second surface 113... Third surface 114... Fourth surface 236... Height reduction part

Claims (5)

It has an inlet for introducing gas, an outlet for discharging gas, and a flow path provided between the inlet and the outlet, and the gas introduced from the inlet side is passed through the flow path. a gas guide path for flowing the gas through the inner space to the outlet;
It has a dielectric layer, and a discharge electrode and a ground electrode that are arranged opposite to each other with the dielectric layer interposed therebetween, and one of the discharge electrode or the ground electrode directly or through another member is connected to the flow. a creeping discharge part that faces the space in the channel and generates a creeping discharge in the channel in response to a periodically changing voltage being applied to the discharge electrode;
A plasma irradiation device comprising:
The flow path is arranged to flow gas along the first direction at least in a region where the creeping discharge portion is provided,
In a second direction perpendicular to the first direction, the creeping discharge part is arranged on one side of the space,
The inner circumferential surface of the flow path in a cut plane cut in a direction perpendicular to the first direction at the position of the creeping discharge portion is closer to the first surface disposed on the one side of the space in the second direction. The second surface disposed on the other side is narrower, and the third and fourth surfaces disposed on both sides of the space in a third direction orthogonal to the first direction and the second direction are narrower. The plasma irradiation device, wherein the interval in the third direction narrows toward the second surface in at least a partial region in the second direction. In at least a partial range from the inlet to the creeping discharge portion, the inner circumferential surface of the flow path in a cut plane perpendicular to the first direction is narrower on the second surface than on the first surface. The plasma according to claim 1, wherein the distance between the third surface and the fourth surface in the third direction becomes narrower toward the second surface in at least a partial region in the second direction. Irradiation device. When the inner edge of the discharge port is projected onto a virtual plane perpendicular to the first direction, the first annular figure is the cut plane cut in the direction perpendicular to the first direction at the position of the creeping discharge part. The plasma irradiation device according to claim 1 or 2, wherein the plasma irradiation device has a positional relationship in which the inner circumferential surface of the flow path is arranged inside the second annular figure when projected onto the virtual plane. The height of the opening of the outlet in the second direction is smaller than the height of the opening of the inlet in the second direction,
According to any one of claims 1 to 3, at least a partial region of the flow path includes a height reduction portion in which the height of the space in the second direction gradually decreases toward the discharge port. plasma irradiation equipment. The dielectric layer includes a first dielectric layer disposed on the one side of the space in the second direction and a second dielectric layer disposed on the other side of the space,
The discharge electrode and the ground electrode are arranged to face each other with a part of the first dielectric layer interposed therebetween,
The plasma irradiation device according to any one of claims 1 to 4, wherein the thickness of the second dielectric layer in the second direction is smaller than the thickness of the first dielectric layer in the second direction. .

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