56 and a distal end side of the convex surface 70, and constitutes a part of the outer peripheral surface of the distal end part body 30. The inclined surface referred to here also includes a vertical surface having an inclined angle of 90° with respect to the direction of the longitudinal axis 36 (Z direction).

The stepped surface 72 is provided with an observation window 64a of the observation optical system 64 and illumination windows 66a of a pair of the illumination optical systems 66.

The observation optical system 64 includes the observation window 64a provided in the stepped surface 72, and a lens system 64b and an imaging element 64c provided in the optical system housing part 68. The imaging element 64c is a charge coupled device (CCD) type or complementary metal oxide semiconductor (CMOS) type image sensor, and captures an observation image taken in from the observation window 64a via the lens system 64b. Then, the imaging element 64c outputs an imaging signal of the observation image to system constituent devices via a signal cable 74 inserted into the endoscope insertion part 12.

The illumination optical system 66 is provided on both sides of the observation optical system 64 in the left-right direction (X direction) in a case in which the distal end part body 30 is viewed from the distal end side, and includes the illumination window 66a provided on the stepped surface 72 and a light guide 76 inserted into the endoscope insertion part 12. An emission end of the light guide 76 is disposed rearward of each illumination window 66a. As a result, illumination light supplied from the light source device to each light guide 76 is emitted from each illumination window 66a.

As described above, in the distal end part body 30, the ultrasonic transducer 50, the treatment tool outlet port 58, and the stepped surface 72 (observation window 64a) are disposed in order from the distal end side to the base end side. That is, the treatment tool outlet port 58 is disposed between the ultrasonic transducer 50 and the observation window 64a. Therefore, a puncture site by the puncture needle 90 can be observed by the observation optical system 64.

Balloon Unit

FIG. 4 is a schematic diagram showing a configuration of an endoscope balloon unit 100 (hereinafter, referred to as a “balloon unit 100”). The balloon unit 100 is of an external type that can be attached to and detached from the endoscope 10. As shown in FIG. 4, the balloon unit 100 comprises an endoscope balloon 110 (hereinafter, referred to as a “balloon 110”), an attachment member 200, and a tube 300. The tube 300 is a pipe line member that sends an ultrasonic transmission medium between the balloon 110 and the attachment member 200.

In a case in which the balloon unit 100 is attached to the endoscope 10, the balloon 110 is mounted on the distal end part body 30, and the attachment member 200 is mounted on the operation part 14. The tube 300 is attached to an outer surface of the endoscope insertion part 12 along a longitudinal direction (the direction along the longitudinal axis 36) of the endoscope insertion part 12, for example, using a medical tape. As a method of fixing the tube 300 to the endoscope insertion part 12, a method using a mounting band, an adhesion wrap, a suture thread, or the like may be used in addition to the medical tape.

Balloon

Next, a configuration of the balloon 110 will be described. In the following description, as in the distal end part body 30 described above, a three-dimensional orthogonal coordinate system including an X axis, a Y axis, and a Z axis that are orthogonal to each other may be used. In a case in which the balloon 110 is mounted on the distal end part body 30, the X axis, the Y axis, and the Z axis of the balloon 110 match the X axis, the Y axis, and the Z axis of the distal end part body 30, respectively. A Z direction is a direction parallel to a longitudinal axis 112 of the balloon 110. Hereinafter, the Z(+) direction side is also referred to as a distal end side, and the Z(−) direction side opposite to the Z(+) direction side is also referred to as a base end side. In addition, a Y direction is an up-down direction in a case in which the balloon 110 is viewed from the distal end side (Z(+) direction side) such that an open window 166 of the balloon 110 is directed upward. In the following description, the Y(+) direction side is also referred to as an upper side, and the Y(−) direction side is also referred to as a lower side. In addition, an X direction is a left-right direction in a case in which the balloon 110 is viewed from the distal end side (Z(+) direction side) such that an open window 166 of the balloon 110 is directed upward. In the following description, the X(+) direction side is also referred to as a left side, and the X(−) direction side is also referred to as a right side.

FIG. 5 is a perspective view of the balloon 110. FIG. 6 is a perspective view of the balloon 110 in a case in which the balloon 110 is viewed from an angle different from an angle in FIG. 5. FIG. 7 is a perspective view of the balloon 110 in a case in which the balloon 110 is viewed from an angle different from the angles in FIG. 5 and FIG. 6. FIG. 8 is a side view of the balloon 110.

As shown in FIGS. 5 to 8, the balloon 110 covers the ultrasonic transducer 50 provided in the distal end part body 30 of the endoscope insertion part 12. The balloon 110 has an overall shape based on a tubular shape that matches the shape of the distal end part body 30, and is formed to extend in a direction of the longitudinal axis 112 (Z direction). The balloon 110 comprises a cover body 120, a connecting body 122, and a fixing body 124 in this order from the distal end side to the base end side of the balloon 110.

Cover Body

The cover body 120 is a portion disposed on the distal end side (Z(+) direction side) of the balloon 110. The cover body 120 has a bottomed tubular shape which is closed on the distal end side (Z(+) direction side) in the Z direction (corresponding to a first direction) corresponding to the longitudinal direction (direction of the longitudinal axis 36) of the endoscope insertion part 12 and has an opening portion 126 (see FIG. 6) formed on the base end side (Z(−) direction side). A cover body space portion 128 for accommodating the ultrasonic attachment part 40 is provided inside the cover body 120. The cover body space portion 128 has substantially the same shape (similar shape) as the ultrasonic attachment part 40 and communicates with the opening portion 126. The cover body space portion 128 constitutes a part of a space portion for accommodating the distal end part body 30 inside the balloon 110.

Here, a configuration of the cover body 120 will be described in detail.

FIG. 9 is an exploded perspective view of the balloon 110. FIG. 10 is an exploded perspective view of the balloon 110 in a case in which the balloon 110 is viewed from an angle different from an angle in FIG. 9. As shown in FIGS. 9 and 10, the cover body 120 of the balloon 110 is configured as a two-layer structure cover body in which an outer part 130 and an inner part 132 are overlapped.

The outer part 130 is formed of an elastic material such as silicon rubber, and is disposed on an outer side of the cover body 120. The outer part 130 is configured in a bottomed tubular shape by a left side surface portion 134, a right side surface portion 135, an inclined surface portion 136, and a bottom surface portion 137. That is, a distal end side of the outer part 130 is closed by the left side surface portion 134, the right side surface portion 135, the inclined surface portion 136, and the bottom surface portion 137, and an outer opening portion 138 is provided on a base end side of the outer part 130. An outer space portion 139 for accommodating the inner part 132 is provided inside the outer part 130. The outer space portion 139 communicates with the outer opening portion 138.

The left side surface portion 134 and the right side surface portion 135 are disposed on a left side and a right side in the outer part 130, respectively, and are each mainly formed of a surface substantially perpendicular to the X direction. In a case in which the balloon 110 is mounted on the distal end part body 30, the left side surface portion 134 and the right side surface portion 135 are disposed at positions facing the standing wall parts 54 of the distal end part body 30 (ultrasonic attachment part 40), respectively. Base end parts of the left side surface portion 134 and the right side surface portion 135 have a shape in which a spacing between the left side surface portion 134 and the right side portion 135 increases toward the base end side in accordance with shapes of the standing wall parts 54 that the left side surface portion 134 and the right side surface portion 135 face (the same applies to the inner part 132 described below).

The inclined surface portion 136 is disposed on an upper side (Y(+) direction side) of the outer part 130. The inclined surface portion 136 has a shape that follows the shape of the transducer surface 52 of the ultrasonic transducer 50. That is, the inclined surface portion 136 is inclined in a curved shape such that a normal line of the inclined surface portion 136 is directed from the upper side toward the distal end side as the inclined surface portion 136 goes toward the distal end side. The inclined surface portion 136 is disposed at a position facing the transducer surface 52 of the ultrasonic transducer 50 in a case in which the balloon 110 is mounted on the distal end part body 30.

The bottom surface portion 137 is disposed on a lower side (Y(−) direction side) of the outer part 130. The bottom surface portion 137 is connected to the left side surface portion 134 and the right side surface portion 135 on both sides in the left-right direction (X direction), and is connected to the inclined surface portion 136 on the distal end side. A portion of the bottom surface portion 137 on the distal end side is formed of a surface perpendicular to the Y direction, and a portion of the bottom surface portion 137 on the base end side with respect to the portion on the distal end side is formed of an inclined surface having a normal line including components in each of a lower side direction and a base end side direction (see FIGS. 7 and 8). A groove portion 140 constituting a communication path, which will be described below, is provided in a portion of the bottom surface portion 137 on the base end side (see FIG. 10).

The inner part 132 is formed of an elastic material such as silicon rubber, and is disposed inside the outer part 130 in the cover body 120. The inner part 132 is configured as an integrally formed object 142 with the connecting body 122 and the fixing body 124. The inner part 132 is a portion that constitutes a distal end side of the integrally formed object 142.

The inner part 132 has the same shape (similar shape) as the outer part 130. That is, the inner part 132 has a bottomed tubular shape formed by a left side surface portion 144, a right side surface portion 145, an inclined surface portion 146, and a bottom surface portion 147. The inner part 132 and the outer part 130 may have partially different shapes (dissimilar shapes) as long as the shapes are substantially the same.

A distal end side of the inner part 132 is closed by the left side surface portion 144, the right side surface portion 145, the inclined surface portion 146, and the bottom surface portion 147. In addition, an inner opening portion 148 is provided on a base end side of the inner part 132 (see FIG. 10). The inner opening portion 148 corresponds to the opening portion 126 of the cover body 120. An inner space portion 149 defined by the left side surface portion 144, the right side surface portion 145, the inclined surface portion 146, and the bottom surface portion 147 is provided inside the inner part 132. The inner space portion 149 communicates with the inner opening portion 148. The inner space portion 149 corresponds to the cover body space portion 128 of the cover body 120.

Configurations (arrangement and orientation) of the left side surface portion 144, the right side surface portion 145, the inclined surface portion 146, and the bottom surface portion 147 in the inner part 132 are the same as the configurations of the left side surface portion 134, the right side surface portion 135, the inclined surface portion 136, and the bottom surface portion 137 in the outer part 130, and description thereof will be omitted to avoid redundancy in the description.

The left side surface portion 144 and the right side surface portion 145 are portions that constitute a cover body fixing portion that is fixed to the distal end part body 30, and include fixing surfaces facing each other in the X direction (corresponding to a second direction). The left side surface portion 144 and the right side surface portion 145 elastically hold the distal end part body 30 with the fixing surfaces.

In a state before the balloon 110 is mounted on the distal end part body 30, a spacing (distance in the X direction) between the left side surface portion 144 and the right side surface portion 145 of the inner part 132 is set smaller than the spacing (distance in the X direction) between the pair of standing wall parts 54 by about 10% to 20%. As a result, in a case in which the balloon 110 is mounted on the distal end part body 30 and the ultrasonic attachment part 40 is accommodated in the inner space portion 149 (cover body space portion 128), the left side surface portion 144 and the right side surface portion 145 are fixed in a state of being in close contact with the corresponding standing wall parts 54, respectively, by an elastic force (contractile force) that acts in a direction in which the left side surface portion 144 and the right side surface portion 145 approach each other.

The outer part 130 is overlapped on an outer side of the inner part 132 configured in this way, thereby forming the cover body 120. Specifically, as shown in FIGS. 9 and 10, the inner part 132 is accommodated in the outer space portion 139 via the outer opening portion 138 of the outer part 130 in a state in which relative positions of the outer part 130 and the inner part 132 are aligned such that the left side surface portion 134, the right side surface portion 135, the inclined surface portion 136, and the bottom surface portion 137 in the outer part 130 face the left side surface portion 144, the right side surface portion 145, the inclined surface portion 146, and the bottom surface portion 147 in the inner part 132. In this case, the outer part 130 and the inner part 132 are integrated by being bonded together on the base end side (Z(−) direction side) which is an opening side of each of the outer part 130 and the inner part 132. As a result, the cover body 120 having a two-layer structure in which the outer part 130 and the inner part 132 are overlapped is configured.

FIG. 11 is a side cross-sectional view of the cover body 120. As shown in FIG. 11, in the cover body 120, the outer part 130 and the inner part 132 are bonded together on the opening side (base end side), so that an inner space (sealed space) is formed in a gap between the outer part 130 and the inner part 132. The internal space is a storage part 150 in which the ultrasonic transmission medium is stored.

The storage part 150 is provided in a gap between the outer part 130 and the inner part 132. Specifically, the storage part 150 is formed of gap spaces between the inclined surface portion 136 and the bottom surface portion 137 in the outer part 130 and the corresponding inclined surface portion 146 and the corresponding bottom surface portion 147 in the inner part 132, and the spaces communicate with each other on the distal end side. The left side surface portion 134 and the right side surface portion 135 in the outer part 130 are fully adhered to the corresponding left side surface portion 144 and the corresponding right side surface portion 145 in the inner part 132, and a gap is not provided therebetween.

The cover body 120 is provided with a communication path 152 between the groove portion 140 (see FIG. 10) provided in the bottom surface portion 137 of the outer part 130 and the bottom surface portion 147 of the inner part 132. One end of the communication path 152 communicates with the storage part 150. In addition, the other end of the communication path 152 communicates with a tube connection port 174, which will be described below.

Of the inclined surface portion 136 of the outer part 130, at least a region facing the transducer surface 52 of the ultrasonic transducer 50 is a bulging portion 154 that is more likely to bulge outward than other regions (including the left side surface portion 134, the right side surface portion 135, and the bottom surface portion 137). The bulging portion 154 is configured as a region having a smaller thickness than other regions. The bulging portion 154 may be provided only in a region of the inclined surface portion 136 of the outer part 130 that faces the transducer surface 52 of the ultrasonic transducer 50, or may be provided over the entire inclined surface portion 136.

In addition, in order to suppress bulging of portions other than the bulging portion 154, for example, a bulge restricting portion (thick portion or adhesion portion) disclosed in JP2023-47488A may be provided around the bulging portion 154. The bulge restricting portion suppresses bulging of portions other than the bulging portion 154 in a case in which the ultrasonic transmission medium is supplied to the storage part 150. A specific configuration of the bulge restricting portion is known, and thus description thereof will be omitted here.

FIG. 12 is a diagram showing a state in which the bulging portion 154 of the outer part 130 bulges outward in a case in which the ultrasonic transmission medium is supplied to the storage part 150. As shown in FIG. 12, in a case in which the ultrasonic transmission medium is supplied to the storage part 150 from the tube 300 connected to the tube connection port 174 via the communication path 152, as shown by a bold line arrow in FIG. 12, the ultrasonic transmission medium passes through the storage part 150 on the lower side (bottom surface portion 147 side) of the inner part 132, the ultrasonic transmission medium is collected in the storage part 150 on the upper side (inclined surface portion 146 side) of the inner part 132 (that is, the storage part 150 at a position where the bulging portion 154 of the outer part 130 is provided), and the bulging portion 154 bulges outward. In a case in which the ultrasonic transmission medium is supplied to the storage part 150, as shown in FIG. 12, the bottom surface portion 137 of the outer part 130 also bulges outward, but the bulging amount thereof is smaller than the bulging amount of the bulging portion 154 of the outer part 130.

With the cover body 120 configured as described above, the storage part 150 in which the ultrasonic transmission medium is stored is provided in the gap between the outer part 130 and the inner part 132, and the bulging portion 154 is provided in the outer part 130. The bulging portion 154 is provided in a region facing the transducer surface 52 of the ultrasonic transducer 50, and is a portion that is more likely to bulge than other regions. As a result, by means of the ultrasonic transmission medium stored in the storage part 150, the bulging portion 154 bulges outward more than regions of the outer part 130 other than the bulging portion 154 while the bulging of the other regions is suppressed. Therefore, it is possible to insert the distal end part body 30 on which the balloon 110 is mounted into a narrow lumen of a bronchus.

In addition, in the cover body 120, since the gap between the outer part 130 and the inner part 132 serves as the storage part 150, it is preferable that a predetermined clearance is provided between the outer part 130 and the inner part 132. In addition, the outer part 130 and the inner part 132 may be made of different materials so that the outer part 130 and the inner part 132 do not stick to each other. In any case, the outer part 130 and the inner part 132 can be prevented from sticking to each other.

Fixing Body

Next, a configuration of the fixing body 124 will be described.

As shown in FIGS. 5 to 8, the fixing body 124 is a portion disposed on the base end side (Z(−) direction side) of the balloon 110. The fixing body 124 is formed of a tubular body having a through-passage 156 that penetrates in the Z direction. The through-passage 156 has a size (inner diameter) that allows the distal end part body 30 to be inserted therethrough, and the opening portion 126 of the cover body 120 is provided at a position intersecting an extension direction of an axis of the through-passage 156. The through-passage 156 constitutes a part of a space portion for accommodating the distal end part body 30 inside the balloon 110. A fixing surface 158 (inner peripheral surface of the through-passage 156) that is fixed to a base end part of the distal end part body 30 (at least on the base end side with respect to the stepped surface 72 of the outlet port forming part 42) is provided inside the fixing body 124. The base end part of the distal end part body 30 is an example of a “fixed part” according to the present invention.

The fixing body 124 constitutes a part of the integrally formed object 142 described above, and is integrally formed with the inner part 132 and the connecting body 122. The fixing body 124 is formed of an elastic material such as silicon rubber, similarly to the inner part 132.

An inner diameter (inner diameter of the through-passage 156) of the fixing body 124 is formed smaller than an outer diameter of the base end part of the distal end part body 30 by about 10% (percent, the same applies hereinafter) to 20%. Therefore, in a case in which the distal end part body 30 is inserted into the through-passage 156 of the fixing body 124 and the fixing body 124 is fixed to the base end part of the distal end part body 30, the fixing body 124 is closely fixed to the base end part of the distal end part body 30 by an elastic force in a diameter-reduced direction of the fixing body 124.

In the present specification, the term “closely fixed” means that the members are fixed in a state of being in close contact with each other without a gap therebetween. As long as the fixing body 124 is fixed to the base end part of the distal end part body 30, the fixing body 124 does not need to be necessarily closely fixed. For example, a gap may be formed in a portion between the fixing surface 158 of the fixing body 124 and the base end part of the distal end part body 30. Note that from the viewpoint of reliably fixing the balloon 110 to the distal end part body 30, it is preferable that the fixing body 124 is closely fixed over the entire circumference of the base end part of the distal end part body 30.

As shown in FIG. 8, a length (length in the Z direction) L1 of the fixing body 124 is preferably in a range of 30% or more and 90% or less with respect to a length (length in the Z direction) L2 of the cover body 120. In the present example, the length L1 of the fixing body 124 is about 50% with respect to the length L2 of the cover body 120. Since the fixing body 124 has a length in the above-described range, an area in which the fixing body 124 is fixed (preferably, closely fixed) to the base end part of the distal end part body 30 is increased, thereby improving the fixation of the balloon 110 to the distal end part body 30.

A position (position in the Z direction) of the fixing body 124 in the balloon 110 is preferably set in a range of 20 mm (millimeters, the same applies hereinafter) or more and 60 mm or less from a distal end of the balloon 110 (cover body 120). By increasing a distance (distance in the Z direction) between the fixing body 124 and the cover body 120, a fixing force of the balloon 110 to the distal end part body 30 can be increased. However, in a case in which the distance between the fixing body 124 and the cover body 120 is too long, the attachment and detachment of the balloon 110 with respect to the distal end part body 30 takes time and effort. Therefore, it is preferable that the position of the fixing body 124 in the balloon 110 is set in the above-described range. In the present embodiment, the base end part of the distal end part body 30 is shown as an example of the fixed part of the endoscope insertion part 12 to which the fixing body 124 is fixed, but the present disclosure is not limited to this, and the fixed part may be the bendable part 32 (preferably, a distal end part of the bendable part 32).

Connecting Body

Next, a configuration of the connecting body 122 will be described.

As shown in FIGS. 5 to 8, the connecting body 122 is a portion disposed between the cover body 120 and the fixing body 124 in the balloon 110. The connecting body 122 connects the cover body 120 (inner part 132) and the fixing body 124 to each other.

The connecting body 122 constitutes a part of the integrally formed object 142 described above, and is integrally formed with the inner part 132 and the fixing body 124. The connecting body 122 is formed of an elastic material such as silicon rubber, similarly to the inner part 132.

The connecting body 122 has a gutter shape that is open on the upper side (Y(+) direction side), and is provided to extend in the direction of the longitudinal axis 112 (Z direction). The connecting body 122 is configured such that a cross section (XY cross section) perpendicular to the longitudinal axis 112 is U-shaped.

The connecting body 122 is formed of a left side surface portion 160, a right side surface portion 162, and a bottom surface portion 164, and is provided with an open window 166 on the upper side. A connecting body space portion 168 defined by the left side surface portion 160, the right side surface portion 162, and the bottom surface portion 164 is provided inside the connecting body 122. The connecting body space portion 168 communicates with the open window 166. In addition, the connecting body space portion 168 communicates with the cover body space portion 128 on a distal end side via the opening portion 126 and communicates with the through-passage 156 on a base end side.

The connecting body space portion 168 constitutes a part of a space portion for accommodating the distal end part body 30 inside the balloon 110, and serves as a space portion for accommodating the outlet port forming part 42 and the body part 44 of the distal end part body 30. In addition, in a case in which the balloon 110 is mounted on the distal end part body 30, the open window 166 of the connecting body 122 exposes the treatment tool outlet port 58, the observation window 64a, and each illumination window 66a to the outside.

As shown in FIGS. 7 and 8, on a distal end side of the bottom surface portion 164 of the connecting body 122, a thick portion 170 that is thicker than on a base end side is provided. The thick portion 170 is formed to protrude to the lower side (Z(−) direction side) with respect to a portion on the base end side of the connecting body 122, and an inclined surface 172 having a normal line including components in each of the lower side direction and the base end side direction is provided on a base end side of the thick portion 170. The tube connection port 174 is formed on the inclined surface 172. The tube connection port 174 communicates with the storage part 150 of the cover body 120 via the communication path 152. The tube connection port 174 may be provided on the cover body 120 instead of the connecting body 122. The tube connection port 174 is a portion to which the tube 300 is connected (see FIGS. 11 and 12), and is an example of a “communication port” according to the present invention.

In the present embodiment, as a preferred aspect, the configuration has been described in which the connecting body 122 has the left side surface portion 160, the right side surface portion 162, and the bottom surface portion 164 and has a gutter shape with the open window 166 on the upper side, but the present invention is not limited to this, and the connecting body 122 may have a shape other than the gutter shape as long as the connecting body 122 can connect the cover body 120 (inner part 132) and the fixing body 124. For example, the connecting body 122 may comprise any one or two of the left side surface portion 160, the right side surface portion 162, or the bottom surface portion 164. In addition, the left side surface portion 160, the right side surface portion 162, and the bottom surface portion 164 are configured in a planar shape along the outer peripheral surface of the distal end part body 30, but the present invention is not limited to this, and may be configured in a strip shape or a rod shape, for example. In addition, a slit or a small hole may be provided in a part of the left side surface portion 160, the right side surface portion 162, and the bottom surface portion 164.

Method of Mounting Balloon

FIG. 13 is a diagram for describing a method of mounting the balloon 110 on the distal end part body 30. XIIIA of FIG. 13 shows a state before the balloon 110 is mounted on the distal end part body 30, and XIIIB of FIG. 13 shows a state after the balloon 110 is mounted on the distal end part body 30.

In a case in which the balloon 110 is mounted on the distal end part body 30, first, as shown in XIIIA of FIG. 13, the distal end part body 30 and the balloon 110 are arranged in a substantially straight line. In this case, relative positions of the balloon 110 and the distal end part body 30 are aligned such that the base end side (the side on which the fixing body 124 is disposed) of the balloon 110 faces the distal end side (the side on which the ultrasonic transducer 50 is disposed) of the distal end part body 30.

Next, the balloon 110 is pushed straight into the distal end part body 30 such that the distal end part body 30 is inserted into the through-passage 156 of the balloon 110 (fixing body 124). Then, in a case in which the balloon 110 is further pushed until the ultrasonic attachment part 40 of the distal end part body 30 is accommodated in the cover body space portion 128 of the cover body 120, as shown in XIIIB of FIG. 13, the balloon 110 is mounted on the distal end part body 30. In this state, the outlet port forming part 42 of the distal end part body 30 is accommodated in the connecting body space portion 168 of the connecting body 122. In addition, the fixing body 124 of the balloon 110 is fixed to the base end part of the distal end part body 30 (at least on the base end side with respect to the stepped surface 72 of the outlet port forming part 42). In this case, since the fixing body 124 of the balloon 110 is closely fixed to the base end part of the distal end part body 30 by the elastic force in the diameter-reduced direction, it is possible to improve the fixation of the balloon 110 to the distal end part body 30.

In addition, in a state in which the balloon 110 is mounted on the distal end part body 30, the ultrasonic attachment part 40 is elastically held by a pair of side surface portions (the left side surface portion 144 and the right side surface portion 145 of the inner part 132) spaced from each other in the left-right direction (X direction) in the cover body 120 to face each other, in addition to the fixation by the fixing body 124 of the balloon 110, so that the cover body 120 is fixed in a state of being in close contact with the standing wall parts 54 of the ultrasonic attachment part 40.

Effect of Balloon

With the balloon 110 according to the present embodiment configured as described above, the configuration is adopted in which the balloon 110 comprises the cover body 120 having a two-layer structure in which the outer part 130 and the inner part 132 are overlapped, and the fixing body 124 connected to the cover body 120 via the connecting body 122, and the fixing body 124 is fixed to the fixed part (the distal end part body 30 or the bendable part 32) of the endoscope insertion part 12. Therefore, the fixation of the balloon 110 to the distal end part body 30 can be improved.

In addition, since the balloon 110 according to the present embodiment has a configuration in which the balloon 110 is fixed by elastically holding the ultrasonic attachment part 40 by a pair of side surface portions (the left side surface portion 144 and the right side surface portion 145) spaced from each other in the left-right direction (X direction) of the cover body 120 to face each other, in addition to the fixation by the fixing body 124, more stable fixation can be ensured in conjunction with the above-described effect.

In the present embodiment, the aspect in which both the fixation by the fixing body 124 and the fixation by the pair of side surface portions of the cover body 120 are provided has been described, but the present invention is not limited to this, and only the fixing by the fixing body 124 may be provided. In this case, a spacing between the pair of side surface portions of the cover body 120 (the distance in the X direction) is set such that the pair of side surface portions weakly sandwich the ultrasonic attachment part 40 or are in contact with the ultrasonic attachment part 40 to a slight extent.

In addition, in the present embodiment, the configuration has been described in which the cover body 120 has a two-layer structure in which the outer part 130 and the inner part 132 are overlapped, but the present invention is not limited to this, and the cover body 120 may be formed of three or more layers as long as the storage part 150 that stores the ultrasonic transmission medium can be provided inside the cover body 120. In addition, in the present embodiment, the entire cover body 120 is formed of a two-layer structure, but the present invention is not limited to this, and only a part of the cover body 120 may be formed of two layers (or three or more layers).

Attachment Member

Next, a configuration of the attachment member 200 will be described. In the following description, an attachment member according to a first configuration example is denoted by reference numeral 200A, and an attachment member according to a second configuration example is denoted by reference numeral 200B. In addition, in a case in which these attachment members 200A and 200B are collectively referred to, the attachment members 200A and 200B are referred to as an attachment member 200.

First Configuration Example

FIG. 14 is a perspective view of the attachment member 200A according to the first configuration example. FIG. 15 is a perspective view of the attachment member 200A according to the first configuration example in a case in which the attachment member 200A is viewed from an angle different from an angle in FIG. 14. FIG. 16 is a top view of the attachment member 200A according to the first configuration example. FIG. 17 is a main part configuration diagram showing a main part (peripheral part of the diameter-reduced part 24) of the operation part 14 of the endoscope 10.

As shown in FIGS. 14 to 16, the attachment member 200A according to the first configuration example has an overall shape based on a conical cylindrical shape whose diameter decreases toward a distal end side (lower side in FIG. 14). The attachment member 200A has a distal end opening 202 provided on the distal end side and a base end opening 204 provided on a base end side.

An insertion slit 206 for allowing the diameter-reduced part 24 of the operation part 14 to pass therethrough is provided in a side surface of the attachment member 200A. The insertion slit 206 is provided to extend along an axial direction of the attachment member 200A from the distal end opening 202 to the base end opening 204. An opening width of the insertion slit 206 is configured to be slightly smaller than an outer diameter of the diameter-reduced part 24 of the operation part 14, and the diameter-reduced part 24 of the operation part 14 can pass through the insertion slit 206 by expansion and contraction of the opening width of the insertion slit 206 due to elastic deformation of the attachment member 200A.

A protruding portion 208 that protrudes further toward the base end side than other portions is provided on the base end side of the attachment member 200A over a partial circumferential range (less than 180 degrees). The protruding portion 208 has a shape that forms a part of the outer peripheral surface of a conical cylindrical shape, similarly to the other portions of the attachment member 200A. A misalignment prevention portion 210 that is formed in a convex shape inward in a circumferential direction is provided on an inner surface of the protruding portion 208.

Meanwhile, as shown in FIG. 17, a stepped portion 26 having a protruding shape is provided in a portion of the operation part 14 on the base end side of the diameter-reduced part 24. The stepped portion 26 is provided in an annular shape along a circumferential direction of a side surface of the diameter-reduced part 24. In addition, the stepped portion 26 is formed to widen in an obtuse angle toward the distal end side. In other words, an angle θ of an inclined surface 26a of the stepped portion 26 with respect to a base end side adjacent surface 27 adjacent to a base end side of the stepped portion 26 is configured to be an obtuse angle that is larger than 90 degrees and smaller than 180 degrees.

The misalignment prevention portion 210 is a portion that engages with the stepped portion 26 configured as described above from the base end side in a case in which the attachment member 200A is mounted on the diameter-reduced part 24 of the operation part 14, and prevents the misalignment of the attachment member 200A with respect to the operation part 14 toward the distal end side.

The attachment member 200A is provided with a supply/discharge port 212. The other end part of the tube 300 is connected to the supply/discharge port 212. The supply/discharge port 212 is provided with a luer cap 213. The luer cap 213 has a tubular shape including a supply/discharge opening 214. The supply/discharge opening 214 communicates with the tube 300 via an internal pipe line (not shown) of the supply/discharge port 212. As a result, in a case in which the ultrasonic transmission medium is supplied from a syringe 310 (see FIG. 18) connected to the luer cap 213 of the supply/discharge port 212 to the supply/discharge opening 214, the ultrasonic transmission medium is sent to the balloon 110 through the tube 300, and the ultrasonic transmission medium is stored in the storage part 150 of the balloon 110. In addition, in a case in which suction is performed from the syringe 310, the ultrasonic transmission medium in the storage part 150 is discharged through the tube 300 and is collected in the syringe 310 via the supply/discharge opening 214.

Two opening windows 216 are provided on the outer peripheral surface of the attachment member 200A. The two opening windows 216 are formed to penetrate the side surface of the attachment member 200A. As a result, the operation part 14 (diameter-reduced part 24) can be visually recognized through the two opening windows 216. The two opening windows 216 need not be provided in the attachment member 200A.

The attachment member 200A comprises a pair of handhold portions 218 provided on both sides (both edges) of the insertion slit