Ultrasonic endoscope

Abstract

Provided is an ultrasonic endoscope and a distal unit thereof that enable depiction of an ultrasonic image based on a base end portion of an ultrasonic transducer. In the ultrasonic endoscope, an outer peripheral surface of a distal unit body includes: a first surface provided on a base end side of the ultrasonic transducer and extending along a long axis of an insertion portion; a second surface provided on a base end side of the first surface and extending along the long axis and on a one-direction side of the first surface in a first direction perpendicular to the long axis; and a step surface connecting a base end side of the first surface and a distal end side of the second surface. A direction perpendicular to both the long axis and the first direction is defined as a second direction. An angle representing an irradiation range of ultrasonic waves emitted from the ultrasonic transducer when the distal unit body is viewed from the second direction side is defined as an effective angle. In a case where an intersection of a tangent line that contacts the ultrasonic transducer at a position on the one-direction side farthest from the step surface and the ultrasonic transducer is defined as a first intersection, the first intersection is included in a range of 1 / 3 on the base end side of the effective angle.

Description

Divisional Application Instructions

[0001] This invention is a divisional application of Chinese national patent application No. 202180090263.4, filed on December 21, 2021, entitled "Ultrasonic Endoscope and its Front End Unit". Technical Field

[0002] This invention relates to an ultrasonic endoscope. Background Technology

[0003] As an ultrasonic endoscope, a type of ultrasonic endoscope is known in which an electronically scanning ultrasonic transducer (also called an ultrasonic transducer array or ultrasonic unit) is provided in the rigid front part (front end unit) of the insertion part constituting the endoscope. Then, while using the ultrasonic transducer to acquire an ultrasonic image of the lesion (which may also be the observation site, examination site, or diagnostic site), a puncture needle, which is led out from the treatment instrument outlet of the rigid front end unit, is inserted into the lesion through the treatment instrument channel to collect cellular tissue from the lesion. For example, in the case of collecting cellular tissue from bronchial lymph nodes, an ultrasonic image of the lymph node is acquired using the ultrasonic endoscope while the puncture needle is inserted into the lymph node.

[0004] In ultrasound-based lymph node observation, if there is a gap between the ultrasound transducer and the bronchial wall, the ultrasound waves cannot be transmitted through the air, thus preventing the acquisition of lymph node images. Therefore, to obtain clear ultrasound images of lymph nodes without using a balloon, the ultrasound transducer needs to be tightly sealed to the bronchial wall.

[0005] Patent document 1 discloses an ultrasonic endoscope that is capable of ultrasonically scanning any lymph node located near or far from the bronchial wall, and defines the angle between the center line of the ultrasonic scanning range (effective angle) and the longitudinal axis (major axis) of the rigid front end.

[0006] Patent Document 2 discloses an ultrasonic endoscope for the same purpose as the invention described in Patent Document 1, in which the front end of the rigid front section on which the ultrasonic transducer is mounted is tilted forward (inclined) to the side opposite to the side where the outlet of the treatment instrument (puncture needle, etc.) is formed. Furthermore, Patent Documents 3 and 4 disclose ultrasonic endoscopes in which, in order to improve insertability or reduce the insertion force of the puncture needle, the front end of the rigid front section is tilted forward in the same manner as the invention described in Patent Document 2.

[0007] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2002-306489 Patent Document 2: Japanese Patent Application Publication No. 2000-354597 Patent Document 3: International Publication No. 2012 / 067010 Patent Document 4: Japanese Patent Application Publication No. 7-143985 Summary of the Invention

[0008] The technical problem that the invention aims to solve To reduce patient burden and improve insertion ease, the insertion portion and rigid tip of the endoscopic ultrasound (EUS) are being further reduced in diameter. However, with the reduction of the rigid tip diameter, the depiction of the ultrasound image based on the base of the ultrasound transducer, i.e., the end near the outlet of the puncture needle (treatment device), becomes important for manual manipulation of the EUS. In this case, it is necessary to increase the contact area between the base of the ultrasound transducer and the bronchial wall, but this is not disclosed or discussed in the aforementioned patent documents.

[0009] In the ultrasonic endoscopes described in Patent Documents 2 to 4, the base of the ultrasonic transducer easily contacts the bronchial wall because the front end of the rigid front section is tilted forward. However, even in this case, it is impossible to determine whether the contact area between the base of the ultrasonic transducer and the bronchial wall can be increased based on the tilt angle of the front end of the rigid front section.

[0010] Furthermore, based on the aforementioned forward tilt angle, the front end of the rigid front section may protrude further outward than the outer periphery of the base end, potentially affecting the operability of the insertion section, such as its insertion capability. Additionally, it is necessary to ensure the coverage of the ultrasonic transducer's electrical wiring.

[0011] Furthermore, if only the front end of the rigid section is tilted, the protrusion angle of the puncture needle relative to the depicted surface of the ultrasonic transducer becomes steep, thus increasing the puncture depth of the puncture needle relative to the lymph node. Consequently, it may become impossible to perform lymph node punctures that were previously possible. To maintain the relative angle between the ultrasonic transducer and the puncture needle, the angle of the treatment instrument tubing located within the front end needs to be gradual. In this case, since the front end becomes longer, it may affect the operability, such as the insertion of the insertion section.

[0012] The present invention was made in view of this situation, and its object is to provide an ultrasonic endoscope and its front end unit that can reliably realize the depiction of ultrasonic images based on the base end of an ultrasonic transducer.

[0013] Technical solutions for solving technical problems To achieve the objectives of this invention, an ultrasonic endoscope includes a front end body disposed at the front end side of the insertion portion and an ultrasonic transducer disposed at the front end side of the front end body. In the ultrasonic endoscope, the outer peripheral surface of the front end body includes: a first surface disposed at the base end side of the ultrasonic transducer along the long axis of the insertion portion; a second surface disposed at the base end side of the first surface along the long axis and located in a direction perpendicular to the long axis relative to the first surface; and a stepped surface connecting the base end side of the first surface and the front end side of the second surface. The direction perpendicular to both the long axis and the first direction is defined as the second direction. The angle representing the irradiation range of the ultrasonic waves emitted from the ultrasonic transducer when observing the front end body from the second direction side is defined as the effective angle. When the intersection of the tangent that contacts the ultrasonic transducer and is in contact with the ultrasonic transducer at the position closest to the first direction side of the stepped surface and the ultrasonic transducer is defined as the first intersection point, the first intersection point is contained within 1 / 3 of the effective angle at the base end side. Furthermore, it is more preferable that the first intersection point is contained within the range of 1 / 4 of the effective angle on the base side.

[0014] According to this ultrasonic endoscope, the contact area between the base of the ultrasonic transducer and the wall can be increased, thus enabling reliable depiction of ultrasonic images based on the base.

[0015] In another aspect of the present invention, an ultrasonic endoscope includes: an outlet disposed on the outer peripheral surface of the front end body, opening to one side and discharging a treatment device; a conduit connected to the outlet within the front end body for insertion of the treatment device; and an observation window of the observation optical system disposed on a stepped surface, wherein, when observing the front end body from a second direction, the second intersection point (the intersection of the centerline and tangent of the conduit connected to the outlet) is located further towards the base of the front end body than the first intersection point. Thus, the treatment device discharged from the outlet can be observed through the observation optical system.

[0016] In another aspect of the present invention, the ultrasonic endoscope has a second intersection point located between the ultrasonic transducer and the stepped surface. This allows observation of the treatment device exiting the port via an optical observation system.

[0017] In another aspect of the present invention, an ultrasonic endoscope includes: an outlet located on the outer peripheral surface of the front end body, opening to one direction and leading to a treatment device; and a conduit connected to the outlet within the front end body for insertion of the treatment device, wherein, when the front end body is viewed from a second direction, the angle between its major axis and the front end of the conduit is 20° to 35°. This ensures operability such as the insertability of the ultrasonic endoscope and prevents an increase in the load applied to the conduit from the treatment device.

[0018] In another aspect of the ultrasonic endoscope according to the present invention, the front end of the tubing has a first front end connected to the outlet and a second front end disposed on the base end side of the first front end. When the front end body is viewed from the second direction side, the first angle formed by the major axis and the first front end is 20° to 35°, and the second angle formed by the major axis and the second front end is 5° to 20°, which is smaller than the first angle. This ensures operability such as the insertability of the ultrasonic endoscope and prevents an increase in the load applied to the tubing from the handling device.

[0019] In another aspect of the present invention, in an ultrasonic endoscope, when the anterior end body is viewed from the second direction side, the angle between the center line of the effective angle and the anterior end of the conduit is 15° to 60°. This allows the treatment instrument to be inserted into the depicted surface of the ultrasonic transducer at an appropriate angle.

[0020] In another aspect of the present invention, an ultrasonic endoscope includes an observation window for an observation optical system on a stepped surface, and the ultrasonic transducer is included within the field of view of the observation optical system. This allows the contact between the ultrasonic transducer and the wall surface to be observed through the observation optical system.

[0021] In another aspect of the present invention, in an ultrasonic endoscope, when observing the anterior end body from a second direction side, the center point of the observation window is located further to one direction side than the ultrasonic transducer. Therefore, the contact between the ultrasonic transducer and the wall surface can be observed through the observation optical system.

[0022] In another aspect of the present invention, an ultrasonic endoscope is provided with an observation window for an observation optical system and an illumination window for an illumination optical system on a stepped surface.

[0023] In another aspect of the present invention, an ultrasonic endoscope includes: an outlet that opens toward a first surface and outlets a treatment device; and an observation window for an observation optical system disposed on a stepped surface. Thus, the treatment device outletped from the outlet can be observed through the observation optical system.

[0024] In another aspect of the ultrasonic endoscope according to the present invention, the front end body includes: an ultrasonic mounting portion on which an ultrasonic transducer is mounted; a first surface forming portion disposed at the base end side of the ultrasonic mounting portion and having a first surface; a main body portion disposed at the base end side of the first surface forming portion and having a second surface; and a protrusion portion disposed at least at the ultrasonic mounting portion and protruding further than the main body portion in a direction opposite to the direction in which one direction is directed. Thus, the front end portion or the entire front end body can be tilted forward relative to the long axis without tilting the ultrasonic transducer forward, thereby ensuring the insertability of the front end body (insertion portion).

[0025] In another aspect of the present invention, an ultrasonic endoscope is provided, wherein the outlet of the outlet treatment device opens toward a first surface, and when the front end body is viewed from a second direction side, a protrusion is formed extending from the opening area of ​​the outlet to the front end side of the ultrasonic mounting part.

[0026] In another aspect of the ultrasonic endoscope according to the present invention, when the anterior end body is viewed from the second direction side, the protrusion has two or more inclined surfaces with different inclination angles relative to the long axis from the base end side of the protrusion toward the anterior end side, and the inclination angle of the inclined surfaces gradually decreases as they move toward the anterior end side of the protrusion. This reduces the burden on the patient.

[0027] In another aspect of the ultrasonic endoscope according to the invention, the outlet of the treatment device opens toward a first surface, and when the front end body is viewed from a second direction side, the position of the outlet in the first direction is aligned with the position of the apex of the ultrasonic transducer in the first direction. A reliable gap is maintained between the front end of the treatment device exiting from the outlet and the ultrasonic transducer.

[0028] In another aspect of the ultrasonic endoscope according to the present invention, the front end body includes: an ultrasonic mounting portion on which an ultrasonic transducer is mounted; a first surface forming portion disposed at the base end side of the ultrasonic mounting portion, having a first surface and an outlet for a treatment device formed on the first surface; and a main body portion disposed at the base end side of the first surface forming portion, having a second surface, wherein when the front end body is viewed from the first direction side, the width of the ultrasonic mounting portion in the second direction is formed to be smaller than the width of the first surface forming portion in the second direction. This allows for miniaturization of the ultrasonic mounting portion and improves insertability.

[0029] In another aspect of the present invention, an ultrasonic endoscope has a connecting inclined surface that connects the base end side of the ultrasonic mounting portion and the front end side of the first surface forming portion.

[0030] To achieve the objective of this invention, the front end unit comprises a front end body disposed on the front end side of the insertion portion of an ultrasonic endoscope and an ultrasonic transducer disposed on the front end side of the front end body. In the front end unit of the ultrasonic endoscope, the outer peripheral surface of the front end body includes: a first surface disposed on the base end side of the ultrasonic transducer along the long axis of the insertion portion; a second surface disposed on the base end side of the first surface along the long axis and located on a direction side perpendicular to the long axis relative to the first surface in a first direction; and a stepped surface connecting the base end side of the first surface and the front end side of the second surface. The direction perpendicular to both the long axis and the first direction is defined as the second direction. The angle representing the irradiation range of the ultrasonic waves emitted from the ultrasonic transducer when observing the front end body from the second direction side is defined as the effective angle. When the intersection of the tangent that contacts the ultrasonic transducer and is in contact with the ultrasonic transducer at the position closest to the first direction side relative to the stepped surface and the ultrasonic transducer is defined as the first intersection point, the first intersection point is included within 1 / 3 of the effective angle on the base end side.

[0031] Invention Effects The present invention can reliably depict ultrasonic images based on the base end of an ultrasonic transducer. Attached Figure Description

[0032] Figure 1 This is an overall view of an ultrasonic endoscope.

[0033] Figure 2 This is a perspective view of the front rigid part of the first embodiment.

[0034] Figure 3 This is an exploded perspective view of the front rigid part of the first embodiment.

[0035] Figure 4 This is a cross-sectional view of the front rigid part of the first embodiment.

[0036] Figure 5 It is a three-dimensional view including the front rigid part of the tangent.

[0037] Figure 6 It is a side view of the front rigid part including the tangent.

[0038] Figure 7 This is a cross-sectional view of the rigid front end portion of the endoscope in the second embodiment.

[0039] Figure 8 This is a cross-sectional view of the rigid front end portion of the endoscope in the third embodiment.

[0040] Figure 9 This is a cross-sectional view of the rigid front end portion of the endoscope in the fourth embodiment.

[0041] Figure 10This is a cross-sectional view of the rigid front end portion of the endoscope according to the fifth embodiment.

[0042] Figure 11 This is a simplified diagram illustrating lymph node puncture based on a puncture needle.

[0043] Figure 12 This is a cross-sectional view of the rigid front end portion of the endoscope according to the sixth embodiment.

[0044] Figure 13 This is a top view of the rigid front end portion of the endoscope according to embodiments 1 to 6.

[0045] Figure 14 This is a top view showing a modified example of the rigid front end portion of the endoscope according to the sixth embodiment.

[0046] Figure 15 This is a cross-sectional view of the rigid front end portion of the endoscope in the seventh embodiment. Detailed Implementation

[0047] The ultrasonic endoscope 1 according to the present invention will be described below with reference to the accompanying drawings.

[0048] [Overall structure of the ultrasonic endoscope of the first embodiment] Figure 1 This is an overall view of the ultrasonic endoscope 1. (See diagram below.) Figure 1 As shown, the ultrasonic endoscope 1 (hereinafter referred to as "endoscope 1") is used to collect cells and tissues from the lesion (or observation site, examination site, diagnosis site). In this embodiment, the lymph nodes of the bronchus are used as an example of the lesion.

[0049] The endoscope 1 comprises: an operating part 10 for the surgeon to hold and perform various operations; an insertion part 12 for insertion into the patient's body; and a universal plug 14. The endoscope 1 is connected via the universal plug 14 to system components such as a processor device and a light source device (not shown) that constitute the endoscope system.

[0050] The operating unit 10 is equipped with various operating components operated by the surgeon, such as a curved lever 16 and a suction button 22, the functions of which will be described later.

[0051] Furthermore, the operation unit 10 is provided with a device insertion channel 23 for inserting into the insertion unit 12 (see reference). Figure 4 Insert the treatment device into the treatment device inlet 24.

[0052] The insertion portion 12 extends from the front end of the operation portion 10 and is formed as a narrow and elongated strip. The insertion portion 12 is composed of a flexible portion 30, a curved portion 32 and a front rigid portion 34 (corresponding to the front end body and front end unit of the present invention) in sequence from the base end side toward the front end side.

[0053] The flexible portion 30 occupies most of the area from the base end of the insertion portion 12 and has flexibility to bend in any direction. When the insertion portion 12 is inserted into the body cavity, the flexible portion 30 bends along the insertion path into the body cavity.

[0054] The bending part 32 is bent in the up-down direction (A2 direction) by rotating the bending rod 16 of the operation part 10 in the A1 direction. By bending the bending part 32, the front rigid part 34 can be oriented in the desired direction.

[0055] Regarding the front-end hardware part 34, details will be provided later. Figures 2 to 4 The device includes: an observation optical system 40 and an illumination optical system 44 for capturing observation images inside the body; an ultrasonic transducer 50 for acquiring ultrasonic images; and an outlet 52 for discharging a treatment device inserted from the treatment device inlet 24.

[0056] For details regarding the universal cord 14, please refer to the following section. Figure 3 and Figure 4 The signal cables 54 and 56, and the light guide 58 are shown. A connector (not shown) is provided at the end of the universal plug 14. This connector connects to the standard system components of the endoscope system, including the processor and light source. Thus, the system components supply the endoscope 1 with the power, control signals, and illumination light required for its operation. Conversely, observation image data acquired by the observation optical system 40 and ultrasound image data acquired by the ultrasound transducer 50 are transmitted from the endoscope 1 to the system components. Furthermore, the observation images and ultrasound images transmitted to the system components are displayed on a monitor, allowing the surgeon or other personnel to observe them.

[0057] Furthermore, the structure of the operation unit 10 is not limited to... Figure 1 As shown, a pair of bend knobs are provided instead of bend lever 16. By rotating the pair of bend knobs, the bending part 32 can be bent in the vertical and horizontal directions. Furthermore, an air supply and water supply button can be provided on the operation part 10. By operating the air supply and water supply button, air or other gases and cleaning liquids can be supplied to the front rigid part 34.

[0058] [Structure of the front rigid part in the first embodiment] Figure 2 This is a perspective view of the front rigid part 34 of the first embodiment. Figure 3 This is an exploded perspective view of the front rigid part 34 of the first embodiment. Figure 4 This is a cross-sectional view of the front rigid part 34 of the first embodiment.

[0059] Furthermore, the Z direction in the figure is parallel to the major axis 38 of the front rigid part 34 (insertion part 12). The Z(+) direction side of the Z direction in the figure is the front end side of the front rigid part 34, and the Z(-) direction side is the base end side of the front rigid part 34. The Y direction in the figure corresponds to the first direction of the present invention, which is perpendicular to the Z direction, and in this embodiment, it is the up-down direction in each figure. The Y(+) direction side, which is one direction side of this Y direction, is the up direction in the figure, and the Y(-) direction side, which is the opposite direction side of the Y direction, is the down direction in the figure. The X direction in the figure corresponds to the second direction of the present invention, which is perpendicular to both the Z and Y directions.

[0060] like Figures 2 to 4 As shown, the front-end rigid part 34 is composed of an ultrasonic block assembly 60, a channel block assembly 70, and an optical system block assembly 80 (especially referring to...). Figure 3 In the front-end rigid portion 34, when the various components are assembled, from the front end side of the front-end rigid portion 34 toward the base end side, it includes an ultrasonic mounting portion 34a, an outlet forming portion 34b (corresponding to the first surface forming portion of the present invention), and a main body portion 34c (see reference). Figure 2 and Figure 4 ).

[0061] The ultrasonic block assembly 60 is formed of an insulating material, such as a resin material or plastic with insulating properties, like polysulfone and polyetherimide. The ultrasonic block assembly 60, from its front end side toward its base end side, includes an ultrasonic mounting portion 34a and an optical system block assembly mounting portion 62 (see reference). Figure 3 In addition, the ultrasonic mounting part 34a is integrally formed with the optical system block assembly mounting part 62.

[0062] Viewed from the X-direction side (corresponding to the second direction side of the present invention) of the front rigid portion 34, an ultrasonic transducer 50 is mounted in the ultrasonic mounting portion 34a in a forward-tilted (inclined) position relative to the long axis 38 towards the Y (-) direction. This ultrasonic transducer 50 is convex, and has ultrasonic transceiver surfaces in which ultrasonic transducers for receiving and transmitting ultrasonic waves are arranged in a curved manner along the long axis 38. Data of ultrasonic images of generated lymph nodes are acquired through this ultrasonic transducer 50. Furthermore, the number of ultrasonic transducers constituting the ultrasonic transducer 50 is not limited.

[0063] Furthermore, when viewing the front rigid portion 34 from the X-direction side, the optical system block assembly mounting portion 62 extends from the region on the Y (-) direction side of the base end of the ultrasonic mounting portion 34a toward its base end side [Z (-) direction side]. Additionally, a locking portion 64 is formed on the Y (+) direction side of the base end of the ultrasonic mounting portion 34a to lock the locking portion 73 of the channel block assembly 70 (described later) (see reference). Figure 4 The locking portion 64, for example, has locking claws that constitute a snap-fit.

[0064] The optical system block assembly mounting section 62 has a roughly semi-cylindrical shape corresponding to the lower half of the two dividing sections (upper and lower parts) that divide the outlet forming section 34b and the main body section 34c in the Y direction. (Reference) Figure 3 Therefore, the optical system block assembly mounting section 62 has a mounting section opening 65 that opens to the Y (+) direction side.

[0065] The mounting opening 65 is parallel to the XZ plane and formed along the Z direction. Inside the mounting opening 65 of the optical system block assembly mounting section 62, a signal cable 54 connecting the ultrasonic transducer 50 and the system components described above is disposed.

[0066] A pair of guide portions 66 are formed on the optical system block assembly mounting portion 62. These guide portions 66 form a mounting portion opening 65 and extend along the mounting portion opening 65 in the Z (-) direction. The optical system block assembly 80, described later, is slidably mounted on these guide portions 66 while being mounted on the optical system block assembly mounting portion 62 in the Z direction. Thus, the optical system block assembly 80 is mounted on the optical system block assembly mounting portion 62, i.e., the ultrasonic block assembly 60, via the pair of guide portions 66.

[0067] The channel block assembly 70, together with the optical system block assembly 80 described later, constitutes the outlet forming portion 34b, and is formed of a known metallic material. The channel block assembly 70 has: an outlet 52 for a treatment device opening towards the Y (+) direction; and a generally rectangular opening forming surface 71 parallel to the XZ plane of the outlet 52 opening and along the Z direction (including the major axis 38, hereinafter the same). Furthermore, in this embodiment, a puncture needle 100 for collecting lymph node tissue is exemplified as the treatment device and will be described.

[0068] At both ends of the opening forming surface 71 in the X direction, a pair of flange surfaces 72 parallel to the XZ surface are formed in the Z direction (see reference). Figure 3 A pair of flange surfaces 72 are used to mount the channel block assembly 70 onto the optical system block assembly 80, extending outward (in the X direction) from both ends of the opening forming surface 71 in the X direction.

[0069] Furthermore, a locking portion 73 is formed on the front end side of the channel block assembly 70, which engages with the locking portion 64 of the ultrasonic mounting portion 34a (see reference). Figure 3 and Figure 4 The locking portion 73 has, for example, a locking hole with locking claws engaged by the locking portion 64.

[0070] An internal conduit 74 is formed inside the channel block assembly 70. The internal conduit 74, together with the treatment device insertion channel 23, constitutes the conduit of the present invention. The front end of the internal conduit 74 is connected to the outlet 52, and the base end of the internal conduit 74 is connected to the treatment device insertion channel 23 within the insertion portion 12. Thus, the front end of the puncture needle 100 inserted from the treatment device inlet 24 is guided to the outlet 52 via the treatment device insertion channel 23 and the internal conduit 74, and is then discharged to the outside from the outlet 52.

[0071] Like the ultrasonic block assembly 60, the optical system block assembly 80 is formed of resin material. The optical system block assembly 80 has a shape corresponding to the upper half of the two dividing parts (upper and lower parts) that divide the outlet forming part 34b and the main body part 34c in the Y direction.

[0072] The optical system block assembly 80, extending from its front end to its base end, includes a pair of channel block assembly mounting portions 81 and an optical system receiving portion 82 spaced apart in the X direction (see reference). Figure 3 In addition, a pair of channel block assembly mounting parts 81 are integrally formed with the optical system receiving part 82.

[0073] When viewed from the X-direction side, the pair of channel block assembly mounting portions 81 extend from a position one level lower than the vertex of the optical system receiving portion 82 on the Y(+) direction side, that is, from the position of the vertex on the Y(-) direction side towards the front end side [Z(+) direction side] of the optical system receiving portion 82.

[0074] Between a pair of channel block assembly mounting portions 81, space is ensured for mounting the channel block assembly 70. A pair of flat surfaces 81a and a pair of support surfaces 81b are formed at the ends of the pair of channel block assembly mounting portions 81 on the Y(+) direction side (see reference). Figure 3 A pair of planes 81a have a shape that is parallel to the XZ plane and along the Z direction.

[0075] A pair of support surfaces 81b are surfaces parallel to a pair of planes 81a. The pair of support surfaces 81b are formed at positions that are displaced from the pair of planes 81a toward the aforementioned spatial side and at positions that are lower than the thickness of the pair of flange surfaces 72 in the Y direction relative to the pair of planes 81a in the Y (-) direction.

[0076] A pair of support surfaces 81b support a pair of flange surfaces 72 from both sides in the X direction. Therefore, via the pair of flange surfaces 72 and the pair of support surfaces 81b, the channel block assembly 70 is slidably supported between the pair of channel block assembly mounting portions 81 in the Z direction. Thus, the channel block assembly 70 can be mounted on the optical system block assembly 80 while sliding in the Z direction. Then, the channel block assembly 70 is bonded and fixed to the optical system block assembly 80.

[0077] When the channel block assembly 70 is mounted on the optical system block assembly 80, the opening forming surface 71 and a pair of planes 81a form a continuous plane 90 (corresponding to the first surface of the present invention) (see reference). Figure 2 The continuous plane 90 is a plane parallel to the XZ plane and along the Z direction, forming part of the outer peripheral surface of the front rigid part 34. In addition, in this embodiment, the outlet 52 opens in the planar continuous plane 90, but it can also open in a surface (first surface) of various shapes such as curved surface, inclined surface or concave and convex surface.

[0078] The optical system receiving portion 82 has a generally semi-cylindrical shape and includes a convex surface 84 and a stepped surface 85. The convex surface 84 corresponds to the second surface of the present invention and forms part of the outer peripheral surface of the front rigid portion 34 (optical system receiving portion 82). This convex surface 84 is located on the Y(+) direction side further than the continuous plane 90 and has a shape along the Z direction. In addition, the convex surface 84 can also be formed into various shapes such as a curved surface, an inclined surface, or a concave-convex surface.

[0079] The stepped surface 85 is an inclined surface connecting the base side of the continuous plane 90 and the front end side of the convex surface 84, forming part of the outer peripheral surface of the front rigid part 34. In addition, the inclined surface mentioned here also includes a vertical surface with an inclination angle of 90° relative to the Z direction.

[0080] An observation window 40a of an observation optical system 40 and an illumination window 44a of a pair of illumination optical systems 44 are provided on the stepped surface 85.

[0081] The observation optical system 40 includes an observation window 40a disposed on the stepped surface 85, a lens system 40b disposed within the optical system housing 82, and an imaging element 40c. The imaging element 40c is a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) type image sensor, which captures the observation image from the observation window 40a via the lens system 40b. Then, the imaging element 40c outputs the imaging signal of the observation image to the system assembly via a signal cable 56 inserted into the insertion portion 12.

[0082] The illumination optical system 44 is disposed on both sides of the observation optical system 40 in the X direction, and includes an illumination window 44a disposed on the stepped surface 85 and a light guide 58 inserted into the insertion portion 12. An emission end of the light guide 58 is disposed behind each illumination window 44a. Thus, illumination light supplied from the system configuration device to each light guide 58 is emitted from each illumination window 44a.

[0083] With the channel block assembly 70 installed, the optical system block assembly 80 slides in the Z direction via a pair of guides 66 and is simultaneously mounted on the optical system block assembly mounting portion 62 of the ultrasonic block assembly 60. At this time, the locking portion 64 of the ultrasonic mounting portion 34a locks the locking portion 73 of the channel block assembly 70. As a result, the movement of the channel block assembly 70 and the optical system block assembly 80 relative to the ultrasonic block assembly 60 in the Z direction is restricted, and the channel block assembly 70 is assembled onto the ultrasonic block assembly 60.

[0084] Furthermore, the front end of the curved portion 32 is externally fixed to the base end of both the optical system housing 82 and the optical system block assembly mounting portion 62 (see reference). Figure 4 Thus, the optical system housing 82 and the optical system block assembly mounting portion 62 are held inseparable in the Y direction by the bending portion 32. As a result, the optical system block assembly 80 is assembled onto the ultrasonic block assembly 60.

[0085] As described above, the ultrasonic block assembly 60, the channel block assembly 70, and the optical system block assembly 80 are combined to form the front rigid section 34. In this front rigid section 34, an ultrasonic transducer 50, an outlet 52, and a stepped surface 85 (observation window 40a) are sequentially arranged from the front end side towards the base end side. That is, the outlet 52 is arranged between the ultrasonic transducer 50 and the observation window 40a. Therefore, it is possible to observe lymph nodes punctured through the bronchial wall by the puncture needle 100 using the observation optical system 40.

[0086] The rigid front end 34 of this embodiment has a shape that increases the contact area between the base end of the ultrasound transducer 50 on the Z (-) direction side, i.e., the base end on the outlet port 52 side of the puncture needle 100, and the bronchial wall when acquiring ultrasound images of lymph nodes through the endoscope 1. This shape will be described in detail below.

[0087] Figure 5 It is a three-dimensional view of the front-end rigid part 34 including the tangent LT. Figure 6 This is a side view of the front rigid portion 34, including the tangent LT. (See image.) Figure 5 and Figure 6As shown, in this embodiment, the shape of the front rigid portion 34, which can increase the contact area between the base end of the ultrasonic transducer 50 and the bronchial wall, is defined by using the tangent LT and the effective angle θ1 of the ultrasonic transducer 50.

[0088] The tangent LT is the line that contacts the ultrasonic transducer 50 and is in contact with the stepped surface 85 at the position (apex) closest to the Y(+) direction. Here, the point where the tangent LT contacts the ultrasonic transducer 50 is designated as contact point P1 (corresponding to the first intersection point of the present invention), and the point where the tangent LT contacts the stepped surface 85 is designated as contact point P2.

[0089] The effective angle θ1 of the ultrasonic transducer 50 represents the angle of the irradiation range R1 of the ultrasonic waves emitted from the ultrasonic transducer 50 when viewed from the X-direction side of the front rigid part 34. Furthermore, Figure 6 The single-dotted line R1a in the figure represents the boundary of a range of 1 / 3 (θ2=1 / 3×θ1) starting from the base side [Z(-) direction side] of the effective angle θ1.

[0090] like Figure 6 As shown, when the rigid front section 34 is viewed from the X-direction side, when the rigid front section 34 contacts the bronchial wall, as indicated by the tangent LT, contacts P1 and P2 contact the bronchial wall. In this case, the area between contacts P1 and P2 in the rigid front section 34 becomes an area where it is difficult to contact the bronchial wall; conversely, the area further forward than contact P1 becomes an area where it is easy to contact the bronchial wall. Therefore, in the base of the ultrasonic transducer 50, the area further forward than contact P1 becomes an area where it is easy to contact the bronchial wall, while the area further back than contact P1 becomes an area where it is difficult to contact the bronchial wall.

[0091] Therefore, in this embodiment, the shape of the front rigid part 34 is adjusted such that the contact point P1 is included within 1 / 3 of the effective angle θ1 at the base (the range of angle θ2 in the figure). This adjustment of the shape of the front rigid part 34 includes adjusting the shape, mounting position, and orientation of the ultrasonic transducer 50, as well as adjusting the shape, formation position, and tilt angle of the stepped surface 85. Furthermore, it is more preferable that the contact point P1 is included within 1 / 4 of the effective angle θ1 at the base.

[0092] By adjusting the shape of the rigid front section 34 in this way, when the rigid front section 34 is in contact with the bronchial wall, and when viewed from the X-direction side, the area between the single-dot doodle line R1a and the contact point P1 at the base of the ultrasonic transducer 50 can reliably contact the bronchial wall (see reference). Figure 6That is, a portion of the base of the ultrasonic transducer 50 can reliably contact the bronchial wall. As a result, the contact area of ​​the base of the ultrasonic transducer 50 relative to the bronchial wall can be increased.

[0093] Furthermore, by adjusting the shape of the front rigid part 34 to shift the position of the contact point P1 further towards the base end side [Z (-) direction side], the contact area of ​​the base end of the ultrasonic transducer 50 relative to the bronchial wall can be further increased.

[0094] In the first embodiment described above, by adjusting the shape of the front rigid portion 34 such that, when viewed from the X-direction side, the contact point P1 is contained within one-third of the effective angle θ1 of the ultrasonic transducer 50 at the base end, the contact area of ​​the base end of the ultrasonic transducer 50 relative to the bronchial wall can be reliably increased. This allows for the reliable depiction of ultrasonic images of lymph nodes based on the base end of the ultrasonic transducer 50.

[0095] [Second Implementation] Next, the rigid front end portion 34 of the endoscope 1 according to the second embodiment of the present invention will be described. By adjusting the shape (angle) of the internal tubing 74, the rigid front end portion 34 of the second embodiment can ensure the operability of the endoscope 1, such as insertion, based on the shortened length of the rigid front end portion 34; reduce the insertion force of the puncture needle 100; and prevent an increase in the load applied to the channel block assembly 70 from the puncture needle 100. Furthermore, since the rigid front end portion 34 of the second embodiment has a substantially the same structure as the rigid front end portion 34 of the first embodiment, the same reference numerals are used for parts that are functionally or structurally the same as those in the first embodiment, and their descriptions are omitted. Descriptions of effects the same as those in the first embodiment are also omitted.

[0096] Figure 7 This is a cross-sectional view of the rigid tip 34 of the endoscope 1 according to the second embodiment. Figure 7 As shown, the internal conduit 74, when viewed from the X-direction side, has a shape that is bent into two segments. Specifically, the internal conduit 74 is composed of a first conduit 74a and a second conduit 74b.

[0097] The first conduit 74a corresponds to the front end and the first front end of the conduit of the present invention, and is connected to the outlet 52 within the channel block assembly 70. The second conduit 74b corresponds to the second front end of the present invention and is disposed at the base end side of the first conduit 74a. The front end of the treatment device insertion channel 23 is connected to the second conduit 74b.

[0098] The angle θ3 (corresponding to the first angle of the present invention) formed by the centerline L2A of the first conduit 74a and the major axis 38 is set to 20° to 35°. Here, the smaller the angle θ3, the longer the length of the intra-block conduit 74 from the front end of the insertion channel 23 to the outlet 52, thus lengthening the rigid front end 34, potentially affecting the operability of the endoscope 1, such as its insertion capability. Conversely, the larger the angle θ3, the greater the load exerted on the channel block assembly 70 by the puncture needle 100 inserted into the intra-block conduit 74. Therefore, in the second embodiment, the angle θ3 is set to 20° to 35°.

[0099] The angle θ4 (corresponding to the second angle of the present invention) formed by the centerline L2B of the second conduit 74b and the major axis 38 is set to 5° to 20° and is smaller than angle θ3. If the angle θ4 of the second conduit 74b is set to the same size as the angle θ3 of the first conduit 74a, the width of the conduit 74 in the Y direction increases, that is, the thickness of the rigid front end 34 in the Y direction increases, resulting in a thicker front end diameter, which may affect the operability of the endoscope 1, such as its insertion capability. Therefore, by setting the angle θ4 of the second conduit 74b to be smaller than the angle θ3 of the first conduit 74a, the increase in the thickness of the rigid front end 34 in the Y direction can be suppressed.

[0100] In the second embodiment described above, by setting the angle θ3 to 20° to 35°, it is possible to ensure the operability of the endoscope 1, which is based on the shortened length of the front rigid part 34, and to prevent an increase in the load applied to the channel block assembly 70 from the puncture needle 100. Furthermore, by setting the angle θ4 to 5° to 20°, which is smaller than the angle θ3, it is possible to ensure the operability of the endoscope 1, including its insertion. In addition, by bending the inner tube 74 into two segments, compared to bending the inner tube 74 into one segment, the insertion force of the puncture needle 100 can be reduced.

[0101] [Third Implementation] Next, the rigid front end portion 34 of the endoscope 1 according to the third embodiment of the present invention will be described. In the rigid front end portion 34 of the above embodiments, by arranging the ultrasonic transducer 50, the outlet 52 and the stepped surface 85 (observation window 40a) from the front end side toward the base side, the lymph nodes punctured from the bronchial wall by the puncture needle 100 can be observed by the observation optical system 40.

[0102] In contrast, the front rigid part 34 of the third embodiment specifically specifies conditions for reliably observing the punctured lymph nodes through the observation optical system 40. Furthermore, since the front rigid part 34 of the third embodiment has essentially the same structure as the front rigid part 34 of the aforementioned embodiments, the same symbols are used for parts that are functionally or structurally the same as those in the aforementioned embodiments, and their descriptions are omitted. Descriptions of effects that are the same as those in the aforementioned embodiments are also omitted.

[0103] Figure 8 This is a cross-sectional view of the rigid tip 34 of the endoscope 1 according to the third embodiment. Figure 8 As shown, when viewing the front rigid section 34 from the X-direction side, the intersection point P3 (corresponding to the second intersection point of the present invention) of the tangent LT and the center line L2A of the first conduit 74a is located closer to the base end of the front rigid section 34 than the contact point P1, and more preferably within the range W between the ultrasonic transducer 50 and the observation window 40a. Furthermore, when the outlet 52 opens further towards the base end of the front rigid section 34 than the stepped surface 85 (observation window 40a), the intersection point P3 is located closer to the base end of the front rigid section 34 than the contact point P1.

[0104] The intersection point P3 corresponds to the location where the puncture needle 100, extending from the outlet 52, begins to puncture the lymph node from the bronchial wall while the ultrasonic transducer 50 is in contact with the bronchial wall. Then, because the intersection point P3 is located within the range W, i.e., in front of the observation window 40a, the puncture of the lymph node from the bronchial wall by the puncture needle 100 can be reliably observed by the observation optical system 40.

[0105] [Fourth Implementation] Next, the rigid front end portion 34 of the endoscope 1 according to the fourth embodiment of the present invention will be described. This rigid front end portion 34 of the fourth embodiment allows the observation of the contact between the ultrasonic transducer 50 and the bronchial wall via the observation optical system 40. Furthermore, since the rigid front end portion 34 of the fourth embodiment has substantially the same structure as the rigid front end portion 34 of the aforementioned embodiments, the same reference numerals are used for parts that are functionally or structurally identical to those in the aforementioned embodiments, and their descriptions are omitted. Descriptions of effects that are identical to those in the aforementioned embodiments are also omitted.

[0106] Figure 9 This is a cross-sectional view of the rigid front end portion 34 of the endoscope 1 according to the fourth embodiment. Figure 9As shown, in the front rigid part 34 of the fourth embodiment, when viewed from the X-direction side, the ultrasonic transducer 50, especially its base end, is included within the field of view of the observation optical system 40 indicated by the symbol VA. Therefore, the contact between the ultrasonic transducer 50, especially its base end, and the bronchial wall can be observed through the observation optical system 40.

[0107] Furthermore, in the front rigid part 34 of the fourth embodiment, when viewed from the X-direction side, as shown by arrow A and dashed line L3 in the figure, the center point C of the observation window 40a is located further towards the Y(+) direction than the ultrasonic transducer 50. Therefore, as described above, the ultrasonic transducer 50 can be included within the field of view of the observation optical system 40, thus enabling observation of the contact between the ultrasonic transducer 50 and the bronchial wall.

[0108] [Fifth Implementation] Next, the rigid tip 34 of the endoscope 1 according to the fifth embodiment of the present invention will be described. This rigid tip 34 of the fifth embodiment allows the puncture needle 100 to be inserted into the depicted surface (lymph node 200) of the ultrasonic transducer 50 at an appropriate angle. Furthermore, since the rigid tip 34 of the fifth embodiment has substantially the same structure as the rigid tip 34 of the aforementioned embodiments, the same reference numerals are used for parts that are functionally or structurally identical to those in the aforementioned embodiments, and their descriptions are omitted. Descriptions of effects that are identical to those in the aforementioned embodiments are also omitted.

[0109] Figure 10 This is a cross-sectional view of the rigid front end portion 34 of the endoscope 1 according to the fifth embodiment. Figure 11 This is a simplified diagram illustrating the puncture of a lymph node 200 using a puncture needle 100. Additionally, in Figure 11 In this context, the symbol DA represents the diameter of a lymph node in 200 mm; for example, let's say it's 200 mm. 20mm. Furthermore, the symbol 'd' represents the Z-direction distance between the base of the ultrasonic transducer 50 and the puncture needle 100 (center of the outlet 52), which is, for example, set to 5mm. Additionally, in Figure 11 In this case, the effective angle θ1 is set to 90° for example.

[0110] like Figure 10 and Figure 11 As shown, in the fifth embodiment, the shape of the front rigid part 34 is adjusted such that, when viewed from the X-direction side, the angle θ5 formed by the center line L4 of the effective angle θ1 of the ultrasonic transducer 50 and the center line L2A of the first conduit 74a is θ5 = 10° to 60°. Specifically, the position and orientation of the ultrasonic transducer 50 and the angle θ3 of the first conduit 74a (refer to...) are adjusted. Figure 7Therefore, the insertion angle of the puncture needle 100 relative to the depicting surface (lymph node 200) of the ultrasonic transducer 50 can be adjusted to θ5, thus preventing the insertion angle of the puncture needle 100 relative to the depicting surface from becoming too steep or too shallow. As a result, the puncture needle 100 can be inserted into the depicting surface of the ultrasonic transducer 50 at an appropriate angle.

[0111] [Sixth Implementation] Next, the rigid tip portion 34 of the endoscope 1 according to the sixth embodiment of the present invention will be described. This rigid tip portion 34 of the sixth embodiment ensures easy insertion and reduces patient burden. Furthermore, since the rigid tip portion 34 of the sixth embodiment has substantially the same structure as the rigid tip portion 34 of the aforementioned embodiments, the same reference numerals are used for parts that are functionally or structurally identical to those in the aforementioned embodiments, and their descriptions are omitted. Descriptions of effects that are identical to those in the aforementioned embodiments are also omitted.

[0112] Figure 12 This is a cross-sectional view of the rigid front end portion 34 of the endoscope 1 according to the sixth embodiment. Figure 12 As shown, in the sixth embodiment, a protrusion 63 is formed on the front rigid portion 34, which, when viewed from the X direction side, protrudes further towards the Y (-) direction than the main body portion 34c. Specifically, the protrusion 63 extends from the opening region of the outlet 52 in the outlet forming portion 34b of the front rigid portion 34, for example, from the center of the outlet 52 indicated by the center line L5 to the front end side of the ultrasonic mounting portion 34a.

[0113] Alternatively, the protrusion 63 may be formed at any position from the opening region of the outlet 52, extending across the front end of the ultrasonic mounting portion 34a. Furthermore, the protrusion 63 may be formed only in the ultrasonic mounting portion 34a. That is, the protrusion 63 may be formed at least in the ultrasonic mounting portion 34a.

[0114] The height Δh of the protrusion 63 is set to, for example, 2.7 mm. Thus, by providing the protrusion 63 at least on the ultrasonic mounting portion 34a, the front end or the entire rigid portion 34 is prevented from tilting forward relative to the major axis 38 in the Y(-) direction; instead, the ultrasonic transducer 50 is tilted forward relative to the major axis 38 in the Y(-) direction at an angle θ6 (θ6 ≥ 110°). This facilitates contact between the base of the ultrasonic transducer 50 and the bronchial wall.

[0115] Here, if it is assumed that the front end or the entire rigid front portion 34 is tilted forward significantly, the insertability of the rigid front portion 34 (insertion portion 12) will deteriorate. However, in the sixth embodiment, since only the ultrasonic transducer 50 is tilted forward, the insertability is improved. As a result, the insertability of the rigid front portion 34 (insertion portion 12) into the patient's body is improved.

[0116] Furthermore, when viewed from the X-direction side, the protrusion 63 has two inclined surfaces 63a and 63b with different inclination angles relative to the major axis 38, extending from the base end side of the protrusion 63 toward the front end side. Of the inclined surfaces 63a and 63b, the inclination angle of the inclined surface 63a on the front end side is smaller than that of the inclined surface 63b on the base end side.

[0117] Thus, by forming inclined surfaces 63a and 63b, which are planar portions, in the protrusion 63, the contact area between the protrusion 63 and the internal wall surface such as the bronchial wall is increased, thereby reducing the contact pressure of the protrusion 63 on the internal wall surface. Furthermore, in the sixth embodiment, since the inclined surface 63a on the front end is formed to be approximately parallel to the long axis 38, the contact pressure of the protrusion 63 on the internal wall surface can be further reduced. As a result, the burden on the patient can be further reduced.

[0118] Furthermore, in the sixth embodiment, two inclined surfaces 63a and 63b are formed on the protrusion 63, but three or more inclined surfaces may also be formed. In this case, the inclination angle of each inclined surface gradually decreases towards the front end of the protrusion 63. Moreover, it is preferable that the inclined surface closest to the front end is formed to be substantially parallel to the major axis 38.

[0119] Figure 13 This is a top view of the rigid front end portion 34 of the endoscope 1 in the first to sixth embodiments. Figure 14 This is a top view showing a modified example of the rigid front end portion 34 of the endoscope 1 according to the sixth embodiment. Figure 13 As shown, when viewed from the Y(+) direction side (corresponding to the first direction side of the present invention), the widths of the ultrasonic mounting portion 34a and the outlet forming portion 34b in the X direction are approximately the same in each of the above embodiments.

[0120] In contrast, such as Figure 14 As shown, in a modified example of the front-end rigid portion 34 in the sixth embodiment, when viewed from the Y(+) direction side, the width WX1 (e.g., 5.7 mm) of the ultrasonic mounting portion 34a in the X direction is formed to be smaller than the width WX2 (e.g., 6.4 mm) of the outlet forming portion 34b in the X direction. Furthermore, by making the width WX1 smaller than the width WX2, an inclined surface 34d (corresponding to the connection inclined surface of the present invention) is formed on the front-end rigid portion 34 to connect the base end side of the ultrasonic mounting portion 34a and the front end side of the outlet forming portion 34b.

[0121] Thus, by reducing the width WX1 of the ultrasonic mounting portion 34a, it is possible to miniaturize the ultrasonic mounting portion 34a and insert it into the bronchial tip. Furthermore, by forming an inclined surface 34d between the ultrasonic mounting portion 34a and the outlet forming portion 34b, insertion is ensured even when only the ultrasonic mounting portion 34a is miniaturized.

[0122] [Seventh Implementation] Next, the rigid tip portion 34 of the endoscope 1 according to the seventh embodiment of the present invention will be described. In the above embodiments, since a balloon, a protrusion for balloon installation, a groove, and a tube are provided on the rigid tip portion 34, the diameter of the rigid tip portion 34 is reduced and its length in the Z direction is shortened. As a result, in the above embodiments, the insertability of the insertion portion 12 is improved, the burden on the patient is reduced, and sterilization in the sterilizer used for cleaning and disinfection is ensured. However, in this case, the puncture needle 100 exiting from the outlet 52 may approach the ultrasonic transducer 50.

[0123] Therefore, the rigid front end 34 of the seventh embodiment has a shape that ensures a gap between the puncture needle 100 extending from the outlet 52 and the ultrasonic transducer 50. Furthermore, since the rigid front end 34 of the seventh embodiment has a substantially the same structure as the rigid front end 34 of the aforementioned embodiments, the same symbols are used for parts that are functionally or structurally the same as those in the aforementioned embodiments, and their descriptions are omitted. Descriptions of effects that are the same as those in the aforementioned embodiments are also omitted.

[0124] Figure 15 This is a cross-sectional view of the rigid front end portion 34 of the endoscope 1 according to the seventh embodiment. Figure 15 As shown, when viewed from the X-direction side, the rigid front end 34 of the seventh embodiment, as indicated by the dashed line L6 in the figure, has its Y-direction position of the outlet 52 aligned with the position of the vertex P4 on the Y(+) direction side of the ultrasonic transducer 50. Therefore, the tip of the puncture needle 100 extending from the outlet 52 passes through a position on the Y(+) direction side further than the vertex P4 of the ultrasonic transducer 50, thus reliably ensuring a gap between the tip of the puncture needle 100 and the ultrasonic transducer 50. Consequently, interference of the puncture needle 100 with the ultrasonic transducer 50 can be reliably prevented.

[0125] [other] In the above embodiments, an endoscope 1 without a balloon cannula in the rigid front section 34 has been described as an example, but the present invention can also be applied to an endoscope 1 with a balloon cannula in the rigid front section 34.

[0126] In the above embodiments, the front-end rigid part 34 is configured by combining the ultrasonic block assembly 60, the channel block assembly 70, and the optical system block assembly 80, but it may also be configured by four or more block assemblies. Furthermore, multiple or all of the block assemblies may be integrally formed. Therefore, the present invention can be applied to various front-end rigid parts 34 having an ultrasonic mounting part 34a, an outlet forming part 34b, and a main body part 34c.

[0127] In the above embodiments, when viewing the front rigid part 34 from the X direction side, an outlet 52 is provided between the ultrasonic transducer 50 and the stepped surface 85 (observation window 40a), but the outlet 52 may also be provided on the base end side of the stepped surface 85 (observation window 40a).

[0128] In the above embodiments, an endoscope 1 (ultrasound bronchoscope) for bronchial lymph node examination was used as an example for description. However, the endoscope 1 of the present invention is not limited to an ultrasound bronchoscope and can also be applied to an ultrasound gastrointestinal endoscope. That is, the present invention can also be applied to various ultrasound endoscopes and the rigid front end portion 34 (front end unit) provided at the front end of its insertion portion 12. Furthermore, the type of treatment device used in the ultrasound endoscope is not limited to the puncture needle 100, and various known treatment devices can be used. In addition, the present invention can also be applied to ultrasound endoscopes and their rigid front end portions that do not have an observation optical system 40 and an illumination optical system 44.

[0129] Symbol Explanation 1-Ultrasonic endoscope, 10-Operating section, 12-Insertion section, 14-Universal plug cord, 16-Angle rod, 22-Suction button, 23-Device insertion channel, 24-Device inlet, 30-Flexible section, 32-Bend section, 34-Rigid tip section, 34a-Ultrasonic mounting section, 34b-Outlet forming section, 34c-Main body, 34d-Inclined surface, 38-Long axis, 40-Observation light Learning system, 40a-Observation window, 40b-Lens system, 40c-Imaging element, 44-Illumination optical system, 44a-Illumination window, 50-Ultrasonic transducer, 52-Outlet, 54-Signal cable, 56-Signal cable, 58-Light guide, 60-Ultrasonic block assembly, 62-Optical system block assembly mounting part, 63-Protrusion, 63a-Sloping surface, 63b-Sloping surface, 64-Locking part, 65-Mounting part opening, 6 6-Guide section, 70-Channel block assembly, 71-Opening forming surface, 72-Flange surface, 73-Locking section, 74-Inner tube within the block, 74a-First tube, 74b-Second tube, 80-Optical system block assembly, 81-Channel block assembly mounting section, 81a-Plane, 81b-Supporting surface, 82-Optical system receiving section, 84-Convex surface, 85-Stepped surface, 90-Continuous plane, 100-Punch needle, 200-Lymph node, C - Center point, DA - Diameter, d - Spacing, L2A - Center line, L2B - Center line, L4 - Center line, L5 - Center line, L6 - Single-dot dashed line, LT - Tangent, P1 - Contact point, P2 - Contact point, P3 - Intersection point, P4 - Vertex, R1 - Irradiation range, W - Range, WX1, WX2 - Width, Δh - Height, θ1 - Effective angle, θ2 - Angle, θ3 - Angle, θ4 - Angle, θ5 - Angle, θ6 - Angle.

Claims

1. An ultrasonic endoscope, characterized in that, have: The front end body is located on the front end side of the insertion part; An outlet is provided at the front end of the main body for the discharge of the treatment device; and The conduit, connected within the front end body to the outlet, allows for the insertion of treatment instruments. The pipeline has a first pipeline section connected to the outlet and a second pipeline section disposed at the base end of the first pipeline section. When viewed from the second direction side, the first angle formed by the major axis of the insertion portion and the centerline of the first conduit portion is 20° to 35°. The second angle formed by the major axis and the centerline of the second pipeline section is 5° to 20° and is smaller than the first angle.

2. The ultrasonic endoscope according to claim 1, characterized in that, The pipeline has two curved sections formed by connecting the first pipeline section and the second pipeline section at the bend.

3. The ultrasonic endoscope according to claim 1 or 2, characterized in that, The first angle is set within the range considering that decreasing the first angle would increase the length of the pipe leading to the outlet and increasing the load applied to the pipe by the treatment device would increase.

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