ENDOSCOPE SYSTEM AND SUCTION UNIT

An endoscope system includes an endoscope and a suction unit. The endoscope includes an insertion portion configured to be inserted into a subject, an operation portion provided on a proximal end side of the insertion portion, and an angle knob provided on the operation portion for operating the bending portion; and an opening provided in the operation portion, wherein the opening is connected to a lumen provided in the endoscope. The suction unit includes a suction conduit, a protrusion inserted into the opening, and a suction button. In a side view perpendicular to an axis of rotation of the angle knob, a center of a top surface of the suction button, a center of the opening, and the angle knob are arranged along an imaginary straight line with the center of the opening located between the center of the top surface of the suction button and the angle knob.

FIELD OF DISCLOSURE

The present disclosure relates to an endoscope system including an endoscope and a suction unit externally provided on the endoscope, and also relates to the suction unit.

BACKGROUND

In a case of bleeding inside a subject or the like in examination and medical treatment with an endoscope, blood and the like are suctioned to identify a bleeding site. However, a suction function built into a conventional endoscope has restrictions on, for example, a pipeline diameter, and suction capacity is insufficient in some cases.

Thus, for example, Japanese Patent Application Laid-Open Publication No. 2012-75746 discloses an endoscope system including a suction device having high suction force, separately from a suction function of an endoscope, the suction device being connected to an externally provided suction tube that is attached to an insertion portion.

SUMMARY OF THE DISCLOSURE

An endoscope system according to an aspect of the present disclosure includes an endoscope and a suction unit. The endoscope includes an insertion portion configured to be inserted into a subject, wherein the insertion portion includes a bending portion, an operation portion provided on a proximal end side of the insertion portion, and an angle knob provided on the operation portion for operating the bending portion; and an opening provided in the operation portion, wherein the opening is connected to a lumen provided in the endoscope. The suction unit including a suction conduit, a protrusion inserted into the opening, and a suction button. In a side view perpendicular to an axis of rotation of the angle knob, a center of a top surface of the suction button, a center of the opening, and the angle knob are arranged along an imaginary straight line with the center of the opening located between the center of the top surface of the suction button and the angle knob.

A suction unit according to an aspect of the present disclosure includes a suction button movable along a first axis; and an endoscope insertable protrusion extending along a second axis. The second axis is tilted relative to the first axis.

DETAILED DESCRIPTION

A configuration according to an aspect of the present disclosure will be described below. Note that, in description below, diagrams based on the embodiment are schematic, and a relation between thickness and width of each part, a thickness ratio of each part, and the like are different from reality. Furthermore, a dimensional relation, a ratio, or the like is different between parts of drawings in some cases.

In a typical endoscope system including an externally provided suction device as in conventional cases, a button unit for operating the suction device is mounted on an operation portion of an endoscope.

However, the conventional button unit has such a problem that it is difficult for a user to perform a suction operation by using the externally provided suction device while operating an angle knob of the endoscope with a single hand to bend a bending portion. In other words, the conventional button unit has such a problem that it is difficult for the user to reach a suction button with, for example, a forefinger or a middle finger while operating the angle knob.

Thus, the user operates the conventional button unit with both hands when simultaneously performing an operation of the angle knob and an operation of the suction button. Note that the user can use a single hand to operate the suction button with, for example, a ring finger or a little finger simultaneously with an operation of the angle knob, but an amount of force on a button pressing operation, correctness, and the like decrease.

Furthermore, the conventional button unit is fixed on the operation portion of the endoscope in a sandwiching manner. Thus, the button unit is easily displaced due to rotation or the like during a procedure with the endoscope, which has been another problem.

Thus, the present disclosure is intended to provide an endoscope system and a suction unit that have improved operability when a user operates, with a single hand, a suction device different from a suction function provided to an endoscope.

An endoscope system1according to the present embodiment will be described below. As illustrated inFIG.1, the endoscope system1includes an endoscope2, a suction unit3, a video processor4of a camera control unit (CCU), and a suction device5. The endoscope system1has a configuration in which not a suction function built into the endoscope2but the suction unit3externally provided and having strong suction force is mounted on the endoscope2.

First, a schematic configuration of the endoscope2according to the present embodiment will be described below. The endoscope2includes an insertion portion6, an operation portion10, and a universal code14.

The insertion portion6is an elongated member that can be inserted into a subject. The insertion portion6includes a distal end portion7, a bending portion8, and a flexible tube portion9. The operation portion10is provided on a proximal end side of the insertion portion6.

The distal end portion7is disposed at a distal end of the insertion portion6. The bending portion8is disposed on a proximal end side of the distal end portion7. The bending portion8is an active bending site and is freely bendable. The flexible tube portion9has flexibility and is disposed on a proximal end side of the bending portion8. The flexible tube portion9is a passive flexible site and is connected to a distal end side of the operation portion10.

The distal end portion7is provided with an observation window (not illustrated). Photographing light incoming through the observation window is photoelectrically converted by an image sensor (not illustrated) built into the distal end portion7. An image pickup cable extending from the image sensor is also inserted in the insertion portion6, the operation portion10, and the universal code14and extended to an endoscope connector15.

The operation portion10is provided with a pair of angle knobs11for operating bending of the bending portion8. The operation portion10is provided with, for example, a plurality of video switches for operating freeze of an endoscope image, release of image pickup, and the like, and a plurality of buttons for operating endoscope functions. Note that the plurality of buttons includes a gas-liquid feeding button (first button)12of a control switch for operating gas-liquid feeding. The angle knob11is provided on the operation portion10for operating the bending portion8. The operation portion10extends in a longitudinal direction with the operation portion10at a first longitudinal end. The axis of rotation of the angle knob11is perpendicular to the longitudinal direction, and the side view is perpendicular to the longitudinal direction. The operation portion10includes the first button12and a second button18or19arranged in the longitudinal direction. In the side view, the first button12is on a first side of the imaginary straight line and the second button18or19is on a second side of the imaginary straight line.

The universal code14is a composite cable extending from a side part of the operation portion10. The endoscope connector15is provided at an extension end of the universal code14. The endoscope connector15is connected to the video processor4of the camera control unit (CCU) including a light source device.

A light source is built into the video processor4. Light from the light source is transmitted to a non-illustrated light guide bundle inserted in the universal code14, the operation portion10, and the insertion portion6.

Light emitted from the video processor4becomes illumination light that is emitted to a subject through an illumination window (not illustrated) provided to the distal end portion7of the insertion portion6. Note that, in the endoscope2, a light source such as an LED may be built in as an illumination apparatus in the distal end portion7.

The endoscope2configured as described above is a single-use disposable product that is discarded after use (used once) but may be a reuse product that is sterilized and reused.

Subsequently, a schematic configuration of the suction unit3according to the present embodiment will be described below. The suction unit3is externally provided to the endoscope2. The suction unit3includes a suction button unit20, a first suction tube21that is inserted into a subject, and a second suction tube22that is disposed outside. Note that the suction unit3has a configuration in which the suction button unit20for performing an operation to turn on and off suction can be mounted on and dismounted from the operation portion10of the endoscope2.

The first suction tube21is, for example, a living-body-compatible silicone tube for insertion into a subject. The first suction tube21is connected to the suction button unit20. At installation, the first suction tube21is helically wound around the insertion portion6of the endoscope2or fixed to the insertion portion6by a band or the like.

the second suction tube22is, for example, a silicone or rubber tube that is disposed outside a subject. One end of the second suction tube22is connected to the suction button unit20. The other end of the second suction tube22is connected to the suction device5as an external instrument.

The suction device5includes a suction pump and a liquid discharge tank (not illustrated). In use, the suction device5may be always driven.

Subsequently, a schematic configuration of the suction button unit20according to the present embodiment will be described below. The suction button unit20is formed of metal or resin. As illustrated inFIG.2, the suction button unit20includes a syringe member23, a pipeline member24, and a piston member25. The body member includes one or more of the pipeline member24and the connection pipe34. The suction unit3includes a suction conduit, a protrusion35inserted into the opening, and a suction button23. In a side view perpendicular to an axis of rotation of the angle knob11, a center of a top surface36of the suction button23, a center of the opening, and the angle knob are arranged along an imaginary straight line with the center of the opening located between the center of the top surface of the suction button and the angle knob. In a direction perpendicular to the longitudinal direction, the center of the top surface36of the suction button23is at a first distance from the protrusion35. Relative to the longitudinal direction, the suction button23is on an opposite side of the operation portion10from the angle knob11. The first button12may be disposed closer to the insertion portion6than the suction button23.

The syringe member23is a bottomed tubular body. A tube joint31is extended from a side periphery of the syringe member23. The tube joint31includes a flow path31aas an internal pipeline communicating with inside of the syringe member23. The second suction tube22is connected to the tube joint31.

As illustrated inFIG.3, a hole vent33is formed at a bottom part32of the syringe member23(refer toFIG.5). A connection pipe34extends from a side periphery of the syringe member23at a predetermined angle.

The connection pipe34includes a flow path34aas an internal pipeline communicating with inside of the syringe member23. The connection pipe34is fitted and connected to the pipeline member24in an airtight (watertight) manner. The flow path34aof the connection pipe34communicates with a flow path24aof the pipeline member24.

Note that the syringe member23is connected such that a longitudinal axial direction of the syringe member23is tilted at a predetermined angle relative to a transverse axial direction of the pipeline member24.

The pipeline member24is an L-shaped block body in which the flow path24ais formed. The connection member24is connected to the first suction tube21. A fixation portion (protrusion)35as a connection rod body extends from one surface of the pipeline member24. The fixation portion35extends in a transverse direction of the pipeline member24.

An attachment rubber50as a circular-disk fixation member is provided on the one surface of the pipeline member24. The attachment rubber50into which the fixation portion35is inserted is fixed to the one surface of the pipeline member24.

The piston member25can be a column-shaped body. The piston member25is provided to the syringe member23in a freely protruding and retracting manner. The piston member25includes a button top (top surface)36of a suction button.

The button top36has a circular-disk flange shape and is provided with rectangular plate guides37at two places on a side periphery (refer toFIG.4). The two guides37are extended from an outer surface of the syringe member23with a predetermined gap therebetween. A shortest distance from a surface of the operation portion10to the top surface36of the suction button23defines a first height. The operation portion10includes a button12,18or19a shortest distance from the surface of operation portion10to a top surface of the button1212,18or19defines a second height. The second height is smaller than the first height.

Each guide37may have a rectangular hole38. A click portion39as a convex portion provided on an outer periphery portion of the syringe member23is fitted into the long hole38. The guide37is linearly guided along the long hole38by the click portion39. Accordingly, sliding of the piston member25relative to the syringe member23is linearly guided.

Note that the click portion39locks the guide37and prevents the piston member25from coming off the syringe member23. In addition, the two guides37restrict rotation of the piston member25about a longitudinal axis.

The piston member25includes a flow path (first suction channel)40as an internal pipeline. The flow path40may be formed in a L shape in a sectional direction orthogonal to the longitudinal axis of the piston member25.

Openings41and42of the flow path40are formed through a side peripheral surface of the piston member25. The two openings41and42may be formed at different outer periphery positions separated from each other by 90° in a section orthogonal to the longitudinal axis of the piston member25. The button20includes the first suction channel40. And the suction tube22having a second suction channel in fluid communication with the first suction channel40. The body member has the third suction channel34ain fluid communication with the first suction channel40. The suction button23extends from a first surface of the body member. The endoscope insertable protrusion35extends from a second surface of the body member. The first surface is on an opposite side of the body member from the second surface. The suction button23is switchable between a first state and a second state. In the first state, fluid flow between the first suction channel40and the third suction channel34ais prevented, and in the second state, fluid flow between the first suction channel40and the third suction channel34ais allowed.

A coil spring43as an urging member is provided inside the syringe member23. The piston member25is urged in a direction protruding from the syringe member23by the coil spring43. In an absence of an applied external force, the suction button23is biased to be in the first state.

Note that a circumferential groove44in which part of the coil spring43is positioned is formed on the piston member25. In addition, a cutout45communicating with the circumferential groove44is formed at part of an outer periphery of the piston member25.

The cutout45is formed at a position where the cutout45communicates with the flow path31aof the tube joint31in a state in which the piston member25protrudes from the syringe member23.

The suction button unit20configured as described above switches between a suction state and a non-suction state in accordance with protrusion and retraction of the piston member25.

In the suction state of the suction button unit20, the piston member25is pressed into the syringe member23against urging force of the coil spring43. Accordingly, the suction button unit20is in a suction operation state in which the piston member25is pressed in by a user.

More specifically, as the piston member25is pressed into the syringe member23, the openings41and42of the flow path40move to positions of the flow path34aof the pipeline member24and the flow path31aof the tube joint31.

Thus, the three flow paths31a,34a, and40communicate with one another in the suction button unit20. Accordingly, the first suction tube21and the second suction tube22communicate with each other.

As a result, negative pressure occurs inside the first suction tube21, the flow paths31a,34a, and40of the suction button unit, and the second suction tube22by suction drive of the suction device5, and the suction unit3switches to the suction state.

In the non-suction state of the suction button unit20, the piston member25is pressed by urging force of the coil spring43in the direction protruding from the syringe member23. Accordingly, the suction button unit20is in a non-suction operation state in which the piston member25is not pressed in by the user.

The piston member25is pressed until the openings41and42of the flow path40reach positions different from the positions of the flow path34aof the pipeline member24and the flow path31aof the tube joint31.

In this state, the flow paths31aand34aare blocked by an outer peripheral surface of the piston member25. In other words, the suction button unit20is in a state in which the three flow paths31a,34a, and40do not communicate with one another. Accordingly, the first suction tube21and the second suction tube22do not communicate with each other.

As a result, the suction unit3switches to the non-suction state in which no negative pressure occurs inside the first suction tube21, the flow paths31a,34a, and40of the suction button unit, and the second suction tube22irrespective of suction drive of the suction device5.

Note that, in the suction unit3, the vent33of the bottom part32of the syringe member23is formed so that negative pressure due to air intake by the suction device5does not occur inside the syringe member23. In other words, the flow path31aof the tube joint31and the cutout45of the piston member25communicate with each other in the suction button unit20so that external air taken into the syringe member23through the vent33is suctioned by the suction device5.

The suction unit3thus configured is a single-use disposable product that is discarded after use (used once). The first suction tube21and the second suction tube22may be disposable products, and the suction button unit20may be a reuse product that is disassembled, sterilized, and reused.

A schematic configuration of the attachment rubber50according to the present embodiment will be described below. As illustrated inFIGS.6to8, the attachment rubber50includes a body51formed of an elastic member such as rubber and having a hat sectional shape.

A hole52is formed at a center of the body51. The fixation portion35of the pipeline member24is inserted into the hole52.

Two convex portions53as engagement portions and a plurality of, six in the present example, ribs54are formed on a back surface side of the body51. The two convex portions53are formed as protrusions opposed to each other across the hole52. The six ribs54protrude in a direction toward a center of the body51. The suction unit3includes the engagement portion53provided around the protrusion35and configured to contact the opening13. The engagement portion53prevents the suction unit3from rotating relative to the operation portion10. The suction unit3is connectable to a medical device by insertion of the endoscope insertable protrusion35into an opening13of the medical device2. When the endoscope insertable protrusion35is inserted into the opening13, the suction unit3is prevented from moving relative to the medical device2. The surface of the endoscope insertable protrusion35includes a rib54. When the endoscope insertable protrusion35is inserted into the opening13, the rib54prevents the endoscope insertable protrusion35from being removed from the opening13.

The body51of the attachment rubber50may be firmly fixed to the one surface of the pipeline member24(bottom surface) of the suction button unit20by fixing, bonding or welding.

The suction unit3is mounted on the operation portion10of the endoscope2. In this case, as illustrated inFIG.9, the fixation portion35of the pipeline member24of the suction button unit20is inserted into a suction cylinder (opening)13of the operation portion10. Then, the attachment rubber50engages with the suction cylinder13in an airtight (watertight) manner. Note that the suction cylinder13is provided adjacent to the gas-liquid feeding button12on one surface of the operation portion10. The opening13is provided in the operation portion10. The opening13is connected to a lumen provided in the endoscope2

In this case, as illustrated inFIG.10, the two convex portions53of the attachment rubber50engage with two concave portions16as engagement counterpart portions provided to the suction cylinder13. The six ribs54of the attachment rubber50lock an outward flange17of the suction cylinder13.

In this state, the suction button unit20is prevented from rotating since the two convex portions53of the attachment rubber50engage with the two concave portions16of the suction cylinder13, respectively. Moreover, the suction button unit20is prevented from falling since the six ribs54of the attachment rubber50lock the outward flange17of the suction cylinder13.

In this manner, the suction button unit20is prevented from falling and rotating by the attachment rubber50when mounted on the suction cylinder13. Note that concave and convex shapes for engagement of the two convex portions53of the attachment rubber50and the two concave portions16of the suction cylinder13as a prevention structure of rotation of the suction button unit20may be interchanged.

Subsequently, a state in which the suction button unit20of the suction unit3is mounted on the operation portion10of the endoscope2will be described below.

As illustrated inFIG.11, a top surface center P1 of the button top36of the suction button unit20is disposed at a predetermined distance d1 from a top surface center P2 of the gas-liquid feeding button12in a direction orthogonal to a longitudinal axis X of the operation portion10and departing from the pair of angle knobs11.

The top surface center P1 of the button top36of the suction button unit20is separated from top surface centers P3, P4, and P5 of a plurality of video switches (second buttons)18and19by predetermined distances d2 and d3 in the direction orthogonal to the longitudinal axis X of the operation portion10and departing from the pair of angle knobs11.

In other words, in a state in which the suction button unit20is connected to the suction cylinder13of the operation portion10, the button top36is disposed at a position further separated from the suction cylinder13on a side opposite the angle knobs11with respect to a central axis (the longitudinal axis X) in a longitudinal direction of the operation portion10than other operation switches such as the gas-liquid feeding button12and the plurality of video switches18and19. In other words, the button top36of the suction button is disposed at a position separated from the suction cylinder13by a predetermined distance with the angle knobs11at an origin.

Note that the button top36is disposed at a position at least separated on the side opposite the angle knobs11with respect to a line connecting the gas-liquid feeding button12and the suction cylinder13. In the present example, the button top36is disposed on a side of the suction cylinder13in a direction intersect or orthogonal to the longitudinal axis X of the operation portion10.

Accordingly, the endoscope system1has a configuration with which the button top36of the suction button unit20can be easily operated.

Moreover, the button top36is disposed such that the top surface center P1 is at a position separated by a predetermined distance d4 on a proximal end side of the top surface center P2 of the gas-liquid feeding button12in a direction along the longitudinal axis X of the operation portion10. In other words, the button top36is disposed on a hand side of the gas-liquid feeding button12, the hand side being opposite to a side of the operation portion10on which the insertion portion6is connected.

Note that the button top36is disposed between the gas-liquid feeding button12and the video switch18in a direction along the longitudinal axis X of the operation portion10.

Accordingly, the endoscope system1has a configuration with which the button top36of the suction button unit20does not interfere when the angle knobs11are operated by fingers of a user hand grasping the operation portion10.

As illustrated inFIG.12, the piston member25of the suction button unit20slides in an axial direction A. The gas-liquid feeding button12slides in an axial direction B when pressed. The axial direction A tilts relative to the axial direction B at a tilting angle θ on a side opposite a side on which the angle knobs11are disposed. Note that a tilt angle as the tilting angle θ is set to be, for example, equal to or smaller than 60° (60≤0). Thus, the suction button unit20can be easily operated since an operation direction of the piston member25has the tilting angle θ (equal to or smaller than 60°) relative to an operation direction of the gas-liquid feeding button12in the manner described above.

Note that, in the present example, the axial direction B in which the gas-liquid feeding button12slides when pressed is a direction along a longitudinal axis of the fixation portion35inserted into the suction cylinder13. In other words, the axial direction A in which the piston member25slides relative to the syringe member23in the suction button unit20tilts relative to the longitudinal axis of the fixation portion35at the tilting angle θ (for example, equal to or smaller than 60°) on the side opposite the side on which the angle knobs11are disposed. The suction button23is movable, for example, when a pressing operation is performed in the first axis direction A (along a first axis A), and the operation portion10includes the first button12movable, for example, when a pressing operation is performed in the second axis direction B (along a second axis B). The first axis direction A is oriented at the tilting angle θ relative to the second axis B. The tilting angle θ may be equal to or less than 60.

Moreover, as illustrated inFIG.13, the suction button unit20is disposed such that the top surface center P1 of the button top36when not operated protrudes from a top surface of the operation portion10at a predetermined height h1 with respect to the top surface center P2 of the gas-liquid feeding button12when not operated. Note that the button top36is disposed such that the top surface center P1 when not operated protrudes from the top surface of the operation portion10at predetermined heights h2 and h3 with respect to the top surface centers P3 and P4 of the two video switches18and19when not operated.

In other words, the suction button unit20is disposed such that the button top36further protrudes from the top surface of the operation portion10than the gas-liquid feeding button12and the two video switches18and19. Accordingly, a position of the button top36as an operation button of the suction unit3can be easily recognized.

When the suction button unit20of the suction unit3is mounted on the endoscope2in use of the endoscope system1, the operation portion10of the endoscope2is usually grasped by a left hand of a user.

When operating the angle knobs11, the user accesses the angle knobs11with, for example, a forefinger or a middle finger through a side of the gas-liquid feeding button12. The suction button unit20according to the present embodiment is connected to the suction cylinder13of the operation portion10not to interfere with an angle operation. Moreover, the button top36is disposed on the hand side of the gas-liquid feeding button12. Accordingly, the user can easily reach and access the angle knobs11from below the gas-liquid feeding button12with, for example, a forefinger or a middle finger of a hand grasping the operation portion10.

The user can simultaneously perform a rotation operation of the angle knobs11and a pressing operation of the button top36of the suction button unit20with a single hand. In other words, when mounted on the operation portion10, the suction button unit20does not restrict an operation of the angle knobs11by the user because of the above-described disposition of the button top36.

For example, the user can operate the two angle knobs11with a thumb and the middle finger grasping the operation portion10and perform a pressing operation of the button top36of the suction button unit20with the forefinger. Thus, the user can perform a suction operation without decrease of an amount of operation force by which the button top36is pressed, correctness, and the like.

Note that the first suction tube21on the insertion portion6side is disposed away from the operation portion10so that the first suction tube21does not to restrict motion of fingers of the user. Accordingly, the fingers of the user can pass below the first suction tube21. In addition, the second suction tube22on the suction device side is disposed along the universal code14so that the second suction tube22is unlikely to interfere with various operations of the endoscope2.

The present disclosure is not limited to the above-described embodiment but may be modified as appropriate without inconsistency with the gist and idea of the disclosure, which can be understood from the claims, the entire specification, and the drawings.

Example 1. An endoscope system comprising:

an endoscope includingan insertion portion that is positioned on a distal end side and inserted into a subject,an operation portion continuously provided on a proximal end side of the insertion portion,an angle knob for operating a bending portion of the insertion portion, anda suction cylinder provided at the operation portion; and

a suction unit includinga suction button unit mounted on the suction cylinder, anda suction button provided at the suction button unit,

wherein the suction button is disposed at a position separated from the suction cylinder by a predetermined distance with the angle knob at an origin.

Example 2. The endoscope system according to Example 1, wherein

the operation portion includes a gas-liquid feeding button, and

the suction button is disposed on a side opposite the angle knob of the operation portion with respect to a line connecting the suction cylinder and the gas-liquid feeding button.

Example 3. The endoscope system according to Example 2, wherein the suction button is disposed closer to a proximal end side of the operation portion than the gas-liquid feeding button.
Example 4. The endoscope system according to Example 2, wherein

the operation portion includes a switch on a proximal end side of the suction cylinder, and

the suction button is disposed between the gas-liquid feeding button and the switch in a direction along a longitudinal axis of the operation portion.

Example 5. The endoscope system according to Example 2, wherein the suction button is disposed at a position separated from the suction cylinder by the predetermined distance in a direction orthogonal to a longitudinal axis of the operation portion.
Example 6. The endoscope system according to Example 2, wherein the suction button is disposed such that a first axial direction in which the suction button slides when a pressing operation is performed is tilted on the side opposite the angle knob at a predetermined angle relative to a second axial direction in which the gas-liquid feeding button slides when a pressing operation is performed.
Example 7. The endoscope system according to Example 6, wherein the predetermined angle is equal to or smaller than 60°.
Example 8. The endoscope system according to Example 2, wherein

the suction button protrudes from a top surface of the operation portion by a first height when not operated,

the gas-liquid feeding button protrudes from the top surface of the operation portion by a second height when not operated, and

the first height is higher than the second height.

Example 9. The endoscope system according to Example 2, wherein the suction button unit includes

a fixation portion that is inserted into the suction cylinder, and

a fixation member that is provided at the fixation portion and engages with the suction cylinder in an airtight manner.

Example 10. The endoscope system according to Example 9, wherein

the fixation member includes an engagement portion, and

the suction cylinder includes an engagement counterpart portion that engages with the engagement portion to prevent rotation of the suction button unit relative to the operation portion.

Example 11. A suction unit mounted on an operation portion of an endoscope, comprising:

a suction button; and

a fixation portion that is inserted into a suction cylinder of the endoscope,

wherein the suction button is disposed such that an axial direction in which the suction button slides when a pressing operation is performed is tilted at a predetermined angle relative to a longitudinal axis of the fixation portion.

Example 12. The suction unit according to Example 11, wherein the predetermined angle is equal to or smaller than 60°.
Example 13. The suction unit according to Example 11, comprising a suction button unit including the suction cylinder, wherein

the suction button is provided at a piston member that slides inside the suction cylinder, and

the fixation portion is provided at the suction button unit.