WO2021255903A1

WO2021255903A1 - Endoscope

Info

Publication number: WO2021255903A1
Application number: PCT/JP2020/023995
Authority: WO
Inventors: 洋佑磯部
Original assignee: オリンパス株式会社
Priority date: 2020-06-18
Filing date: 2020-06-18
Publication date: 2021-12-23

Abstract

Provided is an endoscope in which snagging of a sheath on a cap can be prevented by a simple configuration. An endoscope according to the present invention is provided with: a channel tube which is inserted through a treatment tool; a cap that has the leading end side thereof fitted to the base end side of an opening in a leading end member of an insertion part, that has the base end side covered by the channel tube, and that has a through-hole that, along with the opening and the channel tube, constitutes an insertion channel for the treatment tool; and a cylindrical pressing member which comprises a first body part that is disposed around the outer circumference of the cap being covered by the channel tube and a second body part that is disposed so as to protrude beyond the base end side of the cap in a longitudinal direction. The pressing member has formed on an inner circumference of the second body part a protrusion that performs pressing so as to cause the outer diameter of the channel tube extending toward the base end side to become smaller than the outer diameter of the channel tube that is in contact with the first body part. The base end side of the protrusion is configured to have a tapered surface that works to guide the channel tube in such a manner as to gradually increase the outer diameter thereof.

Description

Endoscope

The present invention relates to an endoscope.

Conventionally, an endoscope has an insertion part inserted into a subject such as a patient to acquire image data in the subject by an imaging device and to perform treatment with a treatment tool or the like. The insertion passage for the treatment tool through which the treatment tool is inserted is such that a resin channel tube is attached to the opening of the tip member of the endoscope insertion portion via a mouthpiece, and the channel tube is attached to the base end side of the mouthpiece. The channel tube is prevented from falling off by covering it with resin or tying it with a thread.

In recent years, from the viewpoint of reducing the influence on the subject and facilitating contact of the imaging device or treatment tool with the affected area, it has been required to shorten the curved portion, reduce the diameter, and increase the bending angle. .. As a result of shortening the bending portion, reducing the diameter, and increasing the bending angle, when the treatment tool is inserted into the insertion passage for the treatment tool with the curved portion curved, the treatment tool is built in as shown in FIG. When the channel tube 170 is expanded and swells in the direction opposite to the bending direction by the tip of the sheath 180 and the sheath 180 is further inserted toward the tip side, the tip of the sheath 180 is on the base end side of the base 150 as shown in FIG. There is a possibility that a stack in which the portion is caught may occur, and in that case, there is a problem that it is difficult to insert or remove the sheath 180.

On the other hand, a pipe member communicating with the treatment tool outlet provided in the tip body and a treatment tool insertion tube connected to the pipe member are provided and formed on the tip side of the pipe member. An endoscope has been proposed in which the first region is a region having a higher pressure resistance than the second region formed on the proximal end side (see, for example, Patent Document 1). In Patent Document 1, since deformation of the first region when the sheath containing the treatment tool is inserted into the treatment tool insertion tube can be suppressed, it is possible to prevent the sheath from being caught in the pipe member.

Japanese Unexamined Patent Publication No. 2018-134276

However, in Patent Document 1, a step is required in which the first region has a higher pressure-resistant crushing property than the second region formed on the proximal end side, and the first region has a higher pressure-resistant crushing property. It has a problem that it becomes difficult to connect to a pipe member.

The present invention has been made in view of the above, and an object of the present invention is to provide an endoscope having a simple structure and capable of preventing the sheath from being caught in the mouthpiece.

In order to solve the above-mentioned problems and achieve the object, the endoscope according to the present invention has a distal end side and a proximal end side in the longitudinal direction of an insertion portion inserted into a subject and having a distal end member on the distal end side. The channel tube through which the treatment tool is inserted and the channel tube are aligned with the proximal end side of the opening of the distal end member, the proximal end side is covered with the channel tube, and the treatment instrument is inserted together with the opening and the channel tube. A mouthpiece having a through hole constituting a passage, a first main body portion arranged around the outer periphery of the mouthpiece covered with the channel tube, and a base portion protruding from the base end side of the mouthpiece in the longitudinal direction are arranged. A tubular holding member having a second main body portion is provided, and the outer diameter of the channel tube extending toward the proximal end side is set on the inner circumference of the second main body portion of the holding member. 1 A protrusion is formed to press the channel tube so as to be smaller than the outer diameter of the channel tube in contact with the main body, and the base end side of the protrusion forms a tapered surface that guides the outer diameter of the channel tube to gradually expand.

Further, in the endoscope according to the present invention, in the above invention, the holding member is formed by joining the first main body portion and the second main body portion.

Further, in the endoscope according to the present invention, in the above invention, an index indicating the mounting position with the mouthpiece is arranged on the outer surface of the holding member.

Further, in the endoscope according to the present invention, in the above invention, the holding member has a notch across the index.

Further, in the endoscope according to the present invention, in the above invention, the difference between the inner diameter of the first main body and the outer diameter of the base end side of the mouthpiece is twice the wall thickness of the channel tube in the natural state. It is as follows.

Further, in the endoscope according to the present invention, in the above invention, the mouthpiece has an abutting surface for contacting with the channel tube.

Further, in the endoscope according to the present invention, the maximum bending angle of the curved portion is 130 ° or more in the above invention.

Further, in the endoscope according to the present invention, in the above invention, the curved portion is configured by connecting a plurality of curved pieces, and the distance between the curved pieces arranged on the tip end side is that of the curved piece arranged on the proximal end side. Less than the interval.

According to the present invention, it is possible to realize an endoscope having a simple configuration and capable of preventing the sheath having a built-in treatment tool from being caught in the mouthpiece.

FIG. 1 is a diagram schematically showing an endoscope system according to an embodiment of the present invention. FIG. 2 is a perspective view schematically showing the tip configuration of the insertion portion of the ultrasonic endoscope according to the embodiment of the present invention. FIG. 3 is a cross-sectional view of the ultrasonic endoscope of FIG. FIG. 4 is an enlarged view of A in FIG. FIG. 5 is a cross-sectional view of FIG. 4 in a state where the holding member is removed. FIG. 6 is a cross-sectional view of an ultrasonic endoscope that does not correspond to the embodiment of the present invention. FIG. 7 is a diagram illustrating the curvature of the curved portion of the endoscope of FIG. FIG. 8 is a top view illustrating a modification 1 of the endoscope according to the embodiment of the present invention. FIG. 9 is a cross-sectional view of FIG. FIG. 10 is a top view of the endoscope according to the second modification of the present embodiment. FIG. 11 is a top view of the endoscope according to the third modification of the present embodiment. FIG. 12 is a top view of the endoscope according to the modified example 4 of the present embodiment. FIG. 13 is a cross-sectional view illustrating the curvature of the endoscope according to the prior art. FIG. 14 is a cross-sectional view illustrating the curvature of the endoscope according to the prior art.

Hereinafter, embodiments of the endoscope according to the present invention will be described with reference to the drawings. The present invention is not limited to these embodiments. Further, in the description of the drawings, the same or corresponding elements are appropriately designated by the same reference numerals. In addition, it should be noted that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, etc. may differ from the reality. Even between the drawings, there may be parts where the relationship and ratio of the dimensions are different from each other.

(Embodiment)
FIG. 1 is a diagram schematically showing an endoscope system 1 according to an embodiment of the present invention. The endoscope system 1 is a system for performing ultrasonic diagnosis in a subject such as a cavity of a living body using an ultrasonic endoscope. As shown in FIG. 1, the endoscope system 1 includes an ultrasonic endoscope 2, an ultrasonic observation device 3, an endoscope observation device 4, a display device 5, and a light source device 6.

The ultrasonic endoscope 2 converts an electrical pulse signal received from the ultrasonic observation device 3 into an ultrasonic pulse (acoustic pulse) by an ultrasonic vibrator provided at the tip thereof and irradiates the subject. At the same time, the ultrasonic echo reflected by the subject is converted into an electrical echo signal expressed by a voltage change and output.

The ultrasonic endoscope 2 has an imaging optical system and an imaging element, and is inserted into the digestive tract (esophagus, stomach, duodenum, large intestine) or respiratory organs (trachea, bronchus) of the subject, and is inserted into the digestive tract or the digestive tract. , It is possible to perform either respiratory imaging. The ultrasonic endoscope 2 has a light guide that guides the illumination light to irradiate the subject at the time of imaging. The tip of the light guide reaches the tip of the insertion portion of the ultrasonic endoscope 2 into the subject, while the proximal end is connected to the light source device 6 that generates illumination light. Further, the ultrasonic endoscope 2 transmits ultrasonic waves to the gastrointestinal tract and organs around the respiratory organs (pancreatic duct, gallbladder, bile duct, biliary tract, lymph node, mediastinal organ, blood vessel, etc.), and the periphery thereof. Receives ultrasonic waves reflected by the organ.

As shown in FIG. 1, the ultrasonic endoscope 2 includes an insertion unit 21, an operation unit 22, a universal cord 23, and a connector 24. The insertion portion 21 is a portion to be inserted into the subject. As shown in FIG. 1, the insertion portion 21 is provided on the tip end side, and is connected to the rigid tip portion 211 including the ultrasonic vibrator 7 and the base end side of the tip portion 211 so as to be bendable. And a flexible tube portion 213 connected to the base end side of the curved portion 212 and having flexibility. Here, inside the insertion portion 21, a light guide for transmitting the illumination light supplied from the light source device 6 and a plurality of signal lines for transmitting various signals are routed, and for inserting a treatment tool. Channels for treatment tools and the like are formed. The curved portion 212 can bend the longitudinal axis of the tip portion 211 in two different directions from each other. For example, the curved portion 212 can be curved on the XY plane shown in FIG. 1 to change the direction of the tip portion 211, and can be curved on the XY plane orthogonal to the XY plane to change the direction of the tip portion 211. Is.

The ultrasonic vibrator 7 is a convex type in which a plurality of piezoelectric elements are provided in an array, the piezoelectric elements involved in transmission / reception are electronically switched, and the transmission / reception of each piezoelectric element is delayed to electronically scan. It is an ultrasonic transducer of.

FIG. 2 is a perspective view schematically showing the tip configuration of the insertion portion of the ultrasonic endoscope according to the first embodiment. As shown in FIG. 2, the tip portion 211 includes an ultrasonic oscillator module 214 holding an ultrasonic oscillator 7, and an endoscope module 215 having an illumination lens 218 that collects illumination light and emits it to the outside. , Equipped with. The endoscope module 215 is provided in the tip member 216, forms a part of the image pickup optical system, and collects the objective lens 217, the image pickup element, and the illumination light that captures the light from the outside and emits the illumination light to the outside. It has an illumination lens 218. Further, the tip member 216 is formed with a treatment tool protrusion 219 that communicates with the treatment tool insertion passage formed in the insertion portion 21 and projects the treatment tool from the tip of the insertion portion 21.

Returning to FIG. 1, the operation unit 22 is connected to the base end side of the insertion unit 21 and is a part that receives various operations from users such as doctors. As shown in FIG. 1, the operation unit 22 includes a bending knob 221 for performing a bending operation on the bending portion 212, and a plurality of operating members 222 for performing various operations. Further, the operation unit 22 is formed with a treatment tool insertion port 223 that communicates with the treatment tool insertion passage and inserts the treatment tool into the treatment tool insertion passage.

The universal cord 23 is a cable extending from the operation unit 22 and having a plurality of signal cables for transmitting various signals, an optical fiber for transmitting illumination light supplied from the light source device 6, and the like.

The connector 24 is provided at the tip of the universal cord 23. The connector 24 includes first to third connector portions 241 to 243 to which the ultrasonic cable 31, the video cable 41, and the optical fiber cable 61 are connected, respectively.

The ultrasonic observation device 3 is electrically connected to the ultrasonic endoscope 2 via the ultrasonic cable 31 (FIG. 1), and sends a pulse signal to the ultrasonic endoscope 2 via the ultrasonic cable 31. At the same time as outputting, an echo signal is input from the ultrasonic endoscope 2. Then, the ultrasonic observation device 3 performs a predetermined process on the echo signal to generate ultrasonic image data.

The endoscope observation device 4 is electrically connected to the ultrasonic endoscope 2 via a video cable 41 (see FIG. 1), and an image signal from the ultrasonic endoscope 2 via the video cable 41. Enter. Then, the endoscope observation device 4 performs a predetermined process on the image signal to generate endoscopic image data.

The display device 5 is configured by using a liquid crystal display or an organic EL (Electro Luminescence), a projector, a CRT (Cathode Ray Tube), or the like, and an ultrasonic image generated by the ultrasonic observation device 3 or an endoscopic observation device 4 Display the endoscopic image etc. generated in.

The light source device 6 is connected to the ultrasonic endoscope 2 via the optical fiber cable 61 (see FIG. 1), and the illumination light that illuminates the inside of the subject via the optical fiber cable 61 is the ultrasonic endoscope. Supply to 2.

FIG. 3 is a cross-sectional view of the ultrasonic endoscope 2 of FIG. 2 in the longitudinal axis direction, and FIG. 4 is an enlarged view of part A of FIG. The longitudinal axis referred to here is an axis along the longitudinal direction of the insertion portion 21. The insertion passage for the treatment tool is composed of a through hole 220 of the tip member 216, a through hole 153 of the base 150, a through hole 154, and a through hole 171 of the channel tube 170.

In the through hole 220 of the tip member 216, the vicinity of the end portion connected to the treatment tool protrusion 219 is inclined with respect to the longitudinal axis of the insertion portion 21, and the treatment tool is inclined from the treatment tool protrusion 219 with respect to the longitudinal axis. It is provided so as to protrude from the surface. Further, a treatment tool entry port 224 parallel to the longitudinal axis is provided at the end portion of the through hole 220 on the base end side. The tip side referred to here is the ultrasonic module 214 side of the insertion portion 21, and the base end side is the operation portion 22 side.

The base 150 has a first base portion 151 and a second base portion 152. The first mouthpiece portion 151 is arranged on the tip end side and is fitted to the treatment tool entrance 224. The through hole 153 in the first base portion 151 is inclined with respect to the longitudinal axis. The second base portion 152 is arranged on the base end side and has a smaller outer diameter than the first base portion 151. The through hole 154 in the second base portion 152 and the second base portion 152 is parallel to the longitudinal axis.

A stepped portion 152a is provided over the entire circumference on the tip end side of the second cap portion 152, that is, on the outer periphery of the first cap portion 151 side, and the end portion on the tip side of the channel tube 170 outerly placed on the second cap portion 152. Is wound and fixed to the step portion 152a with a thread 160. The base end side region 152b of the second base portion 152 has a tapered shape in which the diameter of the through hole 154 is large on the base end side. The first base portion 151 is fixedly bonded to the treatment tool entrance 224 with an adhesive in a state of being fixed by the screw 225. Since the first base portion 151 is temporarily fixed by the screw 225 and then bonded together with an adhesive, it is possible to prevent misalignment and improve assembleability. The screw 225 contact surface of the first base portion 151 is provided with a recessed portion 151x that is one step recessed from the other outer peripheral surface so that the base 150 does not come off with respect to the tip member 216 when temporarily fixed by the screw 225. May be.

The pressing member 100 protrudes in the longitudinal axis direction from the first main body portion 101 arranged on the outer periphery of the proximal end side region 152b of the second cap portion 152 covered by the channel tube 170 and the proximal end side of the cap 150. It has a second main body portion 102 to be arranged, and has a tubular shape. On the inner circumference of the second main body 102 of the pressing member 100, the outer diameter D ₂ of the channel tube 170 near the base end side of the base 150 is smaller than _{the outer diameter D 7} of the channel tube 170 in contact with the first main body 101. A protrusion 103 is formed (see FIG. 5). By pressing the channel tube 170 inflated to cover the base 150 with the protrusion 103, the end of the base 150 can be blocked by the channel tube 170 when the sheath 180 is inserted, and the stack suppressing effect can be improved. can. The base end side of the protrusion 103 forms a tapered surface 105 that guides the outer diameter of the channel tube 170 to gradually expand. The first main body portion 101 and the second main body portion 102 may be integrally molded, but the first main body portion 101 and the second main body portion 102 manufactured as separate bodies may be joined to each other. ..

FIG. 6 is a cross-sectional view of, for example, a conventional ultrasonic endoscope that does not correspond to the embodiment of the present invention. The pressing member 100F of FIG. 6 is different from the pressing member 100 used in the present invention in that a tapered surface is not formed on the base end side of the protrusion 103. When the holding member 100F is used, the swelling of the channel tube 170 by the sheath 180 near the base end side of the base 150 of the channel tube 170 can be prevented, but the swelling of the channel tube 170 extending from the base end side of the holding member 100F is caused by the sheath 180. As shown in FIG. 6, it cannot be suppressed, and the tip of the sheath 180 may be caught by the end of the holding member 100F instead of the end of the base 150. In the pressing member 100 used in the embodiment of the present invention, since the proximal end side of the protrusion 103 is the tapered surface 105, the channel tube 170 extending from the proximal end side of the pressing member 100 is pressed by the tip of the sheath 180. Even when the sheath 180 is inflated, it is possible to effectively prevent the stack in which the tip of the sheath 180 is caught in the end of the pressing member 100.

_{In the present embodiment, it is preferable that the inner diameter D 3} of the protrusion 103 portion of the pressing member 100 is about the same as _{the outer diameter D 0} of the channel tube 170. _{When the inner diameter D 3} at the protrusion 103 portion is larger than the outer diameter D ₀ of the channel tube 170, the channel tube 170 is expanded even at the portion in contact with the protrusion 103 by inserting the sheath 180, and the end portion of the base 150 is expanded. Is exposed, and there is a high possibility that the tip of the sheath 170 will get stuck. Further, when the inner diameter D ₃ at the protrusion 103 portion is smaller than the outer diameter D ₀ _{of the channel tube 170, the inner diameter D 4} at the portion of the channel tube 170 in contact with the protrusion 103 becomes smaller, and the insertion of the sheath 180 deteriorates. The assembleability for inserting the pressing member 100 is also reduced.

Further, from the viewpoint of preventing the sheath 180 from being stacked on the end portion of the base 150, the inner diameter D ₅ _{of the end portion of the base end side region 152b of the base 150 is the inner diameter D 4} at the portion in contact with the protrusion 103 of the channel tube 170. The above is preferable. _{The inner diameter D 4} at the portion of the channel tube 170 in contact with the protrusion 103 is the original diameter of the channel tube 170 due to the relationship between _{the inner diameter D 3} of the protrusion 103 of the pressing member 100 and the outer diameter D _{0 of the channel tube 170.} Since it may be different from the inner diameter D ₁ , it is preferable to set the _{inner diameter D 5} and the inner diameter D _{4 in consideration of the relevant values.} When an adhesive is used when fixing the channel tube 170 to the base 150, it is preferable to consider the thickness of the adhesive.

_{On the other hand, it is preferable that the inner diameter D 6} of the first main body portion 101 of the pressing member 100 is about the same as _{the outer diameter D 7} of the channel tube 170 covering the base end side region 152b of the base 150. _{If the inner diameter D 6} of the first main body 101 is larger than the outer diameter D ₇ of the channel tube 170, a gap is generated between the channel tube 170 and the holding member 100, so that the holding member 100 is eccentric from the base 150. There is a risk of tilting and assembling. In such a case, the holding of the channel tube 170 by the pressing member 100 may not be successful, resulting in poor insertion of the sheath 180. _{Further, if the inner diameter D 6} of the first main body portion 101 is smaller than the outer diameter D ₇ of the channel tube 170, it is necessary to compress the channel tube 170 when assembling the holding member 100 to the base 150, which makes assembly difficult. Become.

_{Further, the difference between the inner diameter D 6} of the first main body portion 101 of the pressing member 100 and the _{outer diameter D 8} of the base end side region 152b of the base 150 is not more than twice the wall thickness t of the channel tube 170 in the natural state. Is preferable.

FIG. 7 is a diagram illustrating the curvature of the curved portion 212 of the ultrasonic endoscope 2 of FIG. The curved portion 212 is configured by connecting a plurality of curved pieces (not shown), and is curved in the vertical and horizontal directions by operating the curved knob 221 (see FIG. 1). Conventionally, the curved portion is configured by connecting a plurality of curved pieces having the same shape, but in the curved portion 212 of the ultrasonic endoscope 2 of the present invention, the distance between the curved pieces arranged on the tip side is the base end. Use one that is smaller than the distance between the curved pieces placed on the side. As shown in FIG. 7, when bending the bending portion 212 by operating the bending knob 221, first, only the tip side of the bending portion 212 is curved by shortening the interval in the bending direction of the bending pieces arranged on the tip side ( 7 (b)) Further, when the bending knob 221 is operated, the distance between the bending pieces from the tip end side to the base end side is shortened in the order in which they are arranged, and the entire bending portion 212 is curved (FIG. 7 (c)). reference).

In recent years, an ultrasonic endoscope 2 having a shorter curved portion, a smaller diameter, and an increased bending angle has been used as compared with the conventional one. For example, the diameter of the curved portion 212 is about 15 mm, which is 13 mm. The length of the curved portion 212 is about 40 mm in the conventional one, which was about 50 mm, and the maximum bending angle is 130 ° or more, and further 150 ° from the one in which the conventional one was about 90 °. The ultrasonic endoscope 2 modified to the above degree has come to be used. When the length of the curved portion 212 is shortened and the curved angle is increased, the angle formed between the adjacent curved pieces in the curved state is also significantly increased. Further, the diameter of the curved portion 212 has been reduced, and even when the bending angle is small, the tip portion of the sheath 180 is likely to be caught on the end portion of the pressing member 100. In the present invention, by making the distance between the curved pieces arranged on the tip side smaller than the distance between the curved pieces arranged on the base end side, the angle formed between the adjacent curved pieces in the curved state becomes smaller. It is possible to prevent the tip portion of the sheath 180 from being caught on the end portion of the pressing member 100.

Further, as the diameter of the curved portion 212 is reduced, the diameter of a plurality of signal cables for supplying power to the ultrasonic module 214 and the image pickup module 215 and transmitting various signals is also reduced, but the cable is less elastic due to the reduction in diameter. It may be a structure. Such a signal cable is more likely to buckle and break due to the bending operation of the bending portion 212 which is shortened and the bending angle is increased. From the viewpoint of preventing disconnection of the signal cable, it is preferable to cover the periphery of the signal cable arranged in the curved portion 212 with a heat-shrinkable tube that can be curved but is hard.

(Modification 1)
FIG. 8 is a top view illustrating a modification 1 of the endoscope according to the embodiment of the present invention, and FIG. 9 is a cross-sectional view of FIG. The holding member 100A according to the first modification has an index indicating the mounting position on the outer surface.

The pressing member 100A has a first main body portion 101A and a second main body portion 102, and the second main body portion 102A is configured to have a larger outer diameter than the first main body portion. In the pressing member 100A, the boundary line between the first main body portion 101A and the second main body portion 102A serves as an index indicating the mounting position of the pressing member 100A.

The pressing member 100A has an index, that is, a notch 106 that crosses the first main body portion 101A and the second main body portion 102A. As shown in FIG. 8, the notch 106 is a notch that penetrates from the outer surface to the inner surface of the pressing member 106A. When the pressing member 100A is assembled to the proximal end side region 152b of the base 150 covered with the channel tube 170, the proximal end side region 152b visible through the transparent channel tube 170 from the notch 106 is confirmed, and the proximal end and the index are confirmed. Assemble the pressing member 100A so that the index is located on the tip side from the base end. This makes it possible to easily attach the holding member 100A to the base 150 at an accurate position. In the first modification, the first main body portion 101A and the second main body portion 102A are used as indexes as different outer diameters, but the index is not limited to this. As the index, a groove formed by a laser or the like or an index may be formed by printing or the like at the boundary between the first main body portion and the second main body portion formed to have the same diameter. Further, the notch 106 is preferably arranged on the UP side having the largest bending angle in order to prevent the tip portion of the sheath 180 from being caught in the notch 106.

(Modification 2)
FIG. 10 is a top view illustrating a modification 2 of the endoscope according to the embodiment of the present invention. The holding member 100B according to the modified example 2 has an index indicating the mounting position on the outer surface as in the modified example 1. The pressing member 100B has an index, that is, a notch 106B that crosses the first main body portion 101B and the second main body portion 102B, and the notch 106B is provided up to the base end side of the second main body portion 102B. By providing the notch 106B up to the base end side of the second main body portion 102B, the pressing member 100B can be easily removed when the channel tube 170 is replaced or the like.

(Modification 3)
FIG. 11 is a top view illustrating a modified example 3 of the endoscope according to the embodiment of the present invention. In the holding member 100D according to the second modification, the first main body portion 101D and the second main body portion 102D are formed to have the same outer diameter, and the notch 106D is arranged in the second main body portion 102D. The notch 106D is formed so that the end portion of the notch 106D on the first main body portion 101D side coincides with the boundary between the first main body portion 101D and the second main body portion 102D. In the third modification, the end portion of the notch 106D on the first main body portion 101D side serves as an index.

(Modification example 4)
FIG. 12 is a sectional view taken along the longitudinal axis for explaining a modification 4 of the endoscope according to the embodiment of the present invention. In the fourth modification, the base 150E has an abutting surface 155 for contacting the end of the channel tube 170 and the pressing member 100E.

The base 150E has an abutting surface 155 for abutting the end portions of the channel tube 170 and the pressing member 100E at the end portion of the first base portion 151E on the second base portion 152E side. The abutting surface 155 is a surface orthogonal to the longitudinal axis direction.

The first main body portion 101E of the pressing member 100E is formed to have a length that allows the entire second base portion 152E to be pressed. In the fourth modification, since the area where the base 150E and the holding member 100E overlap is large, the holding member 100E can be assembled more accurately to the base 150E, and the holding member 100E when the channel tube 170 receives a load can be performed more accurately. Can be prevented from tilting.

Further effects and variations can be easily derived by those skilled in the art. Thus, the broader aspects of the invention are not limited to the particular details and representative embodiments described as described above. Thus, various modifications can be made without departing from the spirit or scope of the overall concept of the invention as defined by the attached claims and their equivalents.

1 Endoscopic system 2 Ultrasonic endoscope 3 Ultrasonic observation device 4 Endoscopic observation device 5 Display device 6 Light source device 7 Ultrasonic oscillator 21 Insertion part 22 Operation part 23 Universal cord 24 Connector 31 Ultrasonic cable 41 Video Cable 61 Optical fiber cable 100 Holding member 101 1st main body 102 2nd main body 103 Protrusion 105 Tapered surface 106 Notch 150 Base 151 1st base 152

2nd base

153, 154, 171, 220 Through hole 155 Butt Surface 170 Channel tube 180 Sheath 211 Tip part 212 Curved part 213 Flexible tube part 214 Ultrasonic transducer module 215 Endoscopic ultrasound module 221 Curved knob 222 Operation member 223 Treatment tool insertion port 224 Treatment tool entrance 225 Screw

Claims

A channel tube that communicates the distal end side and the proximal end side of the insertion portion that is inserted into the subject and has the distal end member on the distal end side in the longitudinal direction and inserts the treatment tool.
A mouthpiece having a front end side fitted to the base end side of the opening of the tip member, the base end side being covered with the channel tube, and having a through hole forming an insertion passage of the treatment tool together with the opening and the channel tube.
A tubular portion having a first main body portion arranged around the outer periphery of the mouthpiece covered with the channel tube and a second main body portion arranged so as to project in the longitudinal direction from the base end side of the mouthpiece. Holding member and
Equipped with
On the inner circumference of the second main body of the holding member, a protrusion that presses the outer diameter of the channel tube extending toward the proximal end so as to be smaller than the outer diameter of the channel tube in contact with the first main body. Is formed, and the base end side of the protrusion is an endoscope having a tapered surface that guides the outer diameter of the channel tube to gradually expand.
The endoscope according to claim 1, wherein the holding member is formed by joining the first main body portion and the second main body portion.
The endoscope according to claim 1, wherein an index indicating a mounting position with the mouthpiece is arranged on the outer surface of the holding member.
The endoscope according to claim 3, wherein the holding member has a notch across the index.
The endoscope according to claim 1, wherein the difference between the inner diameter of the first main body and the outer diameter of the base end side of the base is not more than twice the wall thickness of the channel tube in a natural state.
The endoscope according to claim 1, wherein the mouthpiece has an abutting surface for contacting with the channel tube.
The endoscope according to claim 1, wherein the maximum bending angle of the curved portion is 130 ° or more.
The endoscope according to claim 7, wherein the curved portion is configured by connecting a plurality of curved pieces, and the distance between the curved pieces arranged on the tip end side is smaller than the distance between the curved pieces arranged on the proximal end side.