Ultrasonic endoscope

Abstract

To provide an ultrasonic endoscope capable of reducing a diameter of the endoscope while ensuring visibility of the tip.SOLUTION: An ultrasonic endoscope 1 includes: a tip 34 disposed on a tip side of an insertion part; an ultrasonic transducer 50 provided at the tip 34 for emitting an ultrasonic wave toward one side of a first direction orthogonal to a longitudinal axis direction; an acoustic lens 52 provided on an external surface of the ultrasonic transducer 50; and an imaging part 300 arranged more on a proximal end side in the longitudinal axis direction than the acoustic lens 52. When, viewed in a first direction, a straight line passing through a central part of the acoustic lens 52 in the longitudinal axis direction and a second direction orthogonal to a first direction and extending in the longitudinal axis direction is represented as a reference line RL, the imaging part 300 is disposed at a position offset to one side of the second direction from the reference line RL when viewed in the first direction and an optical axis OA2 of the imaging part 300 intersects with the reference line RL.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic endoscope, and more particularly to an ultrasonic endoscope having an ultrasonic transducer at the tip of an insertion section. [Background technology]

[0002] Known ultrasonic endoscopes include those that have a convex ultrasonic transducer at the tip of an insertion section, and have a treatment tool outlet disposed on the proximal side of the ultrasonic transducer at the tip (see, for example, Patent Document 1).

[0003] In the examination using the ultrasonic endoscope, for example, while an ultrasonic transducer acquires an ultrasonic image of the treatment site, a puncture needle (treatment tool) introduced into the body through the treatment tool insertion channel and the treatment tool outlet is inserted into the treatment site to collect cells. At this time, the treatment tool's introduction direction is changed by the raising and lowering movement of the stand provided in the stand housing section, so that the desired position can be treated.

[0004] In addition to the standing platform, the distal end of the insertion section is provided with an imaging section for observing the treatment target area and an illumination section for emitting illumination light toward the treatment target area. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 179909 Summary of the Invention [Problem to be solved by the invention]

[0006] In general, endoscopes are desired to have a smaller diameter in order to reduce the burden on the patient. However, in a convex-type ultrasound endoscope, the imaging unit, the ultrasound cable connected to the ultrasound transducer, and the stand unit including the stand are located at the tip. Therefore, if the diameter of the tip is reduced, the imaging unit and the stand unit will interfere with each other. Furthermore, if the imaging unit and the stand unit are located in a position that avoids interference, the ultrasound transducer and the stand unit will not be easily captured in the captured endoscopic image, which may make it difficult to ensure visibility of the tip.

[0007] The present invention has been made in view of the above circumstances, and has as its object to provide an ultrasonic endoscope that can be made thinner in diameter while ensuring visibility at the tip. [Means for solving the problem]

[0008] The ultrasonic endoscope of the first aspect comprises a tip portion arranged at the tip side of an insertion portion extending along the longitudinal axis direction, an ultrasonic transducer provided at the tip portion and emitting ultrasonic waves toward one side in a first direction perpendicular to the longitudinal axis direction, an acoustic lens provided on the outer surface of the ultrasonic transducer, and an imaging unit arranged on the base end side in the longitudinal axis direction of the acoustic lens, wherein when viewed from the first direction, if a straight line passing through the center of the acoustic lens in a second direction perpendicular to the longitudinal axis direction and extending in the longitudinal axis direction is taken as a reference line, when viewed from the first direction, the imaging unit is arranged at a position offset from the reference line to one side in the second direction, and the optical axis of the imaging unit intersects with the reference line.

[0009] In the ultrasonic endoscope of the second aspect, in the first aspect, the intersection of the optical axis and the reference line is located closer to the tip end in the longitudinal axis direction than the acoustic lens.

[0010] In the ultrasonic endoscope of the third aspect, in the first or second aspect, the center of the acoustic lens is located in the fourth quadrant of the four quadrants divided horizontally and vertically based on the center of the image acquired by the imaging unit.

[0011] The ultrasonic endoscope of a fourth aspect is any one of the first to third aspects, wherein the angle between the optical axis and the reference line is 5 degrees or less.

[0012] The ultrasonic endoscope of the fifth aspect is any one of the first to fourth aspects, in which the tip portion has a stand unit arranged at a position overlapping with the imaging unit in the longitudinal axis direction, and the stand unit has a stand that is freely rotatable around a rotation axis along the second direction, and a case member that defines a space portion to accommodate the stand.

[0013] The ultrasonic endoscope of the sixth aspect is the fifth aspect, and is arranged in a position where at least a partial area of ​​the imaging unit overlaps with the stand unit when viewed from the first direction. [Effects of the Invention]

[0014] According to the present invention, it is possible to reduce the diameter of an endoscope while ensuring visibility of the tip portion. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the overall configuration of an ultrasonic endoscope according to this embodiment. [Figure 2] FIG. 2 is a perspective view of the tip portion of the ultrasonic endoscope shown in FIG. [Figure 3] FIG. 3 is a diagram showing the tip member as viewed from the Z(+) direction side. [Figure 4] FIG. 4 is a diagram showing an endoscopic image. [Figure 5] FIG. 5 is a diagram showing the positional relationship between the imaging unit, the stand unit, and the acoustic lens in the distal end member, as viewed from the Z(+) direction side. [Figure 6] FIG. 6 is a side view of the imaging unit as seen from the X(-) direction side. [Figure 7] FIG. 7 is a perspective view showing the arrangement of the imaging unit and the platform unit. [Figure 8] FIG. 8 is a diagram showing an endoscopic image. [Figure 9]FIG. 9 is a diagram showing the arrangement of the imaging unit and the platform unit. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0017] [Overall configuration of the ultrasonic endoscope] FIG. 1 is a diagram showing the overall configuration of an ultrasonic endoscope (hereinafter abbreviated as "endoscope") 1 according to an embodiment of the present invention.

[0018] 1, the endoscope 1 of this embodiment includes an operation section 10 that is held by an operator to perform various operations, an insertion section 12 that is inserted into a patient's body cavity, and a universal cord 14. The endoscope 1 is connected via the universal cord 14 to a system configuration device that includes a processor device and a light source device (not shown).

[0019] The operation unit 10 is provided with various operation members that are operated by the surgeon, such as a pair of angle knobs 16, a standing operation lever 18, an air / water supply button 20, and a suction button 22.

[0020] The operation section 10 is provided with a treatment tool introduction port 24 on its distal end side. The treatment tool introduced through the treatment tool introduction port 24 is inserted into a treatment tool insertion channel that is inserted inside the insertion section 12.

[0021] The insertion section 12 extends from the tip of the operating section 10 along the longitudinal axis, and is configured to be thin and long overall. The insertion section 12 has, in order from the base end to the tip end, a flexible section 30, a bending section 32, and a tip section 34. The insertion section 12 is an example of the insertion section of the present invention, and the tip section 34 is an example of the tip section of the present invention.

[0022] The flexible section 30 occupies the majority of the proximal end side of the insertion section 12 and has flexibility that allows it to bend in any direction. When the insertion section 12 is inserted into a body cavity, the flexible section 30 bends along the insertion path within the body cavity.

[0023] The bending portion 32 bends up and down and left and right by rotating the pair of angle knobs 16 of the operation unit 10. By bending the bending portion 32, the distal end 34 can be directed in a desired direction.

[0024] The tip section 34 is equipped with a tip member 36 (see FIG. 2), which will be described later. The tip member 36 is disposed on the tip side of the insertion section 12. The tip member 36 has an ultrasonic observation section 100 on its tip side and an endoscopic observation section 110 on the base end side of the ultrasonic observation section 100.

[0025] 1 contains internal components such as an ultrasound cable, an electric cable, a light guide, and a fluid tube. A connector is provided at an end (not shown) of the universal cord 14, and by connecting this connector to the above-mentioned system configuration device, control signals, power, illumination light, liquid, gas, and the like required for operating the endoscope 1 are supplied from the system configuration device to the endoscope 1. In addition to the above-mentioned internal components, the insertion section 12 also has internal components such as a treatment tool insertion channel, a bending operation wire, and a standing table operation wire inserted therein.

[0026] Ultrasound image data and endoscopic image data acquired by the endoscope 1 (ultrasound observation section 100 and endoscopic observation section 110) are transmitted to the system component device from the endoscope 1. Each piece of data transmitted to the system component device is processed by the system component device and displayed on a monitor (not shown) as an endoscopic image and an ultrasound image, respectively.

[0027] Next, the configuration of the tip portion 34 (tip member 36) will be described with reference to Fig. 2. Fig. 2 is a perspective view showing the appearance of the tip member 36, and shows a state in which a stand 70 (described later) is positioned in a laid-down position.

[0028] Hereinafter, when describing the configuration of each part of the tip member 36, for convenience of explanation, an X, Y, Z three-dimensional Cartesian coordinate system will be used. The Z direction in the drawing indicates the up-down direction, with the Z(+) direction side indicating the upper side and the Z(-) direction side indicating the lower side. The X direction in the drawing indicates the direction perpendicular to the Z direction, with the X(+) direction side indicating the left side and the X(-) direction side indicating the right side. The Y direction in the drawing indicates the direction perpendicular to both the Z direction and the X direction, with the Y(+) direction side indicating the tip side and the Y(-) direction side indicating the base side. Note that each of the above directions refers to the direction when the tip member 36 is viewed from the tip side, with the acoustic lens 52 of the ultrasonic transducer 50 (described later) facing upward.

[0029] The Y direction corresponds to the longitudinal axis direction of the insertion portion of the present invention. The Z direction corresponds to the first direction of the present invention, with the Z(+) direction side corresponding to one side of the first direction of the present invention and the Z(-) direction side corresponding to the other side of the first direction of the present invention. The X direction, which is perpendicular to both the Y direction (longitudinal axis direction) and the Z direction (first direction), corresponds to the second direction of the present invention.

[0030] As shown in FIG. 2, the distal end member 36 has an ultrasonic observation section 100 and an endoscopic observation section 110 on the Y(-) direction side (proximal end side) of the ultrasonic observation section 100.

[0031] The ultrasonic observation unit 100 and the endoscopic observation unit 110 are connected to each other via a balloon groove 120 formed between the ultrasonic observation unit 100 and the endoscopic observation unit 110. A balloon covering the ultrasonic transducer 50 is attached to this balloon groove 120. The balloon groove 120 is formed over the entire circumferential direction around the Y direction (longitudinal axis direction).

[0032] The ultrasonic observation unit 100 has an ultrasonic transducer 50 , which is held in a housing 54 .

[0033] The ultrasonic transducer 50 is a convex type in which multiple ultrasonic vibrators are arranged in an arc shape along the Y direction (longitudinal axis direction). The upper surface (surface on the Z(+) direction side) of the ultrasonic transducer 50 is configured as an acoustic lens 52, and ultrasonic waves are emitted from this acoustic lens 52 toward the Z(+) direction side (one side in the first direction). Specifically, when viewed from the X direction, ultrasonic waves emitted from the acoustic lens 52 (multiple ultrasonic vibrators) are scanned in a fan shape (convex scanning) from diagonally rearward (Y(-) direction side and Z(+) direction side) to diagonally forward (Y(+) direction side and Z(+) direction side). The emission direction of the ultrasonic waves scanned in this way includes at least a component on the Z(+) direction side. It is sufficient that the emission direction of most of the ultrasonic waves to be scanned includes a component in the Z(+) direction, and it is also possible that the emission direction of some of the ultrasonic waves does not include a component in the Z(+) direction (for example, when it is in the Y(+) direction or when it is a direction including a component in the Z(-) direction). Data for generating an ultrasonic image is acquired by the ultrasonic transducer 50 configured in this manner. The ultrasonic transducer 50 is provided at the tip 34 and is an example of the ultrasonic transducer of the present invention. The acoustic lens 52 is an example of the acoustic lens 52 of the present invention.

[0034] The acoustic lens 52 is provided on the outer surface of the ultrasonic transducer 50, and serves to converge ultrasonic waves from the ultrasonic transducer 50 toward the observation target area, and is overlaid on an acoustic matching layer (not shown). The acoustic lens 52 is made of, for example, a silicone resin (millable type silicone rubber (HTV rubber), liquid silicone rubber (RTV rubber), etc.), a butadiene resin, a polyurethane resin, etc., and is mixed with powder of titanium oxide, alumina, silica, etc. as needed.

[0035] The endoscopic observation section 110 has a substantially cylindrical main body member 112. This main body member 112 is made of an insulating material, such as a resin material including plastics such as methacrylic resin, polyphenylsulfone resin, polyetherimide resin, polyetheretherketone resin, and polycarbonate.

[0036] The main body member 112 has an observation window 40 for observing the inside of the subject, illumination windows 42A and 42B for illuminating the inside of the subject, and an air / water nozzle 44 for cleaning the observation window 40 etc. The observation window 40 is disposed on the Y(-) direction side (proximal end side) of the stand 70.

[0037] The main body member 112 has a stand-up platform housing section 60 that houses the stand-up platform 70. The stand-up platform housing section 60 has an opening 46 that is rectangular in plan view from the Z(+) direction. The opening 46 is formed in the main body member 112 and opens toward the Z(+) direction. In this embodiment, the opening direction of the opening 46 is a direction that includes only a Z(+) direction component when viewed from the X direction (i.e., a direction perpendicular to the XY plane). Note that the opening direction of the opening 46 may be any direction that includes at least a Z(+) direction component, and may be, for example, a direction diagonally forward when viewed from the X direction (i.e., a direction that includes both Z(+) and Y(+) direction components).

[0038] A treatment tool such as a puncture needle is led out of the distal end member 36 through the opening 46. This treatment tool is led out toward the ultrasonic scanning range of the ultrasonic transducer 50. In addition, a stand housing section 60 is provided on the Z(-) direction side (lower side) of the opening 46.

[0039] A treatment tool outlet 62 communicating with the standing table accommodation space 61 of the standing table accommodation section 60 is provided on the Y(-) direction side (proximal end side) of the standing table accommodation section 60. The treatment tool outlet 62 communicates with the treatment tool introduction port 24 of the operation section 10 via a treatment tool insertion channel inserted through the insertion section 12 (see FIG. 1). As a result, the treatment tool introduced from the treatment tool introduction port 24 is guided from the treatment tool outlet 62 to the standing table accommodation space 61 via the treatment tool insertion channel.

[0040] The stand 70 is accommodated in the stand accommodation space 61 of the stand accommodation unit 60. The stand 70 is disposed on the Y(-) direction side of the ultrasonic transducer 50. The stand 70 is rotatable about a rotation shaft 72 disposed along the X direction, and is rotated between an upright position and a lying position. The upright position refers to the position of the stand 70 when the tip end side of the stand 70 (the side opposite the rotation shaft 72) moves to the end position on the Y(-) direction side within the rotatable range of the stand 70 (i.e., the position where the stand 70 stands up facing the Z(+) direction). The lying position refers to the position of the stand 70 when the tip end side of the stand 70 moves to the end position on the Y(+) direction side within the rotatable range of the stand 70 (i.e., the position where the stand 70 is lying down facing the Y(+) direction).

[0041] The stand 70 is made of a metal material such as stainless steel, and has a treatment tool guide surface 70B on its upper surface. The treatment tool introduced into the stand housing section 60 is guided along the treatment tool guide surface 70B and is led out through the opening 46 of the stand housing section 60 to the outside.

[0042] The elevator 70 configured in this manner moves (raises and lowers) between an upright position and a reclined position around the pivot 72 when the elevator operation lever 18 (see FIG. 1) is operated. For example, by operating the elevator operation lever 18 to move the elevator 70 and adjust the angle of the elevator 70 from the reclined position, it is possible to change the direction (angle of ejection) of the treatment tool guided by the treatment tool guiding surface 70B of the elevator 70 and ejected from the opening 46. The main body member 112 is provided with an elevator unit, which will be described later. The elevator unit is a unit formed by integrating multiple components (such as the elevator 70 and the case member 402) that constitute the elevator storage section 60.

[0043] As shown in FIG. 2, the illumination windows 42A and 42B are respectively arranged on the illumination window arrangement surfaces 36A and 36B provided on the main body member 112. Light emitting portions constituting the illumination unit are housed inside the illumination windows 42A and 42B. These light emitting portions are respectively connected to a light source device via a light guide. Illumination light transmitted from the light source device via the light guide is irradiated from the respective light emitting portions to the treatment target site via the illumination windows 42A and 42B.

[0044] The observation window 40 is disposed on the observation window placement surface 36C provided on the main body member 112. An imaging system unit having an imaging optical system, a solid-state imaging element, a circuit board, and a signal cable that constitute the imaging section (camera section) is housed inside the observation window 40. The observation window 40 and the imaging system unit constitute the imaging section. As a result, light (reflected light) from the treatment target area (subject) illuminated by the illumination windows 42A and 42B is taken in through the observation window 40, and the light is imaged as an observation image on the solid-state imaging element via the imaging optical system. Data for generating an endoscopic image is acquired by this imaging section.

[0045] The air and water nozzle 44 is arranged on a nozzle arrangement surface 36D provided on the main body member 112. When the air and water button 20 (see FIG. 1) is operated, a cleaning liquid such as water or air (fluid) is sprayed from the air and water nozzle 44 toward the observation window 40, etc., to clean the observation window 40, etc.

[0046] <Description of the Ultrasonic Endoscope of the Present Disclosure> Next, the principles applied to the ultrasonic endoscope 1 according to the present disclosure will be described. Fig. 3 is a diagram of the tip member 36 of the ultrasonic endoscope 1 as seen from the Z(+) direction side. Fig. 3 is a diagram showing the positional relationship between the optical axes OA1 and OA2 of the imaging unit 300 and the acoustic lens 52. Fig. 4 is a diagram showing an endoscopic image 200 acquired through the observation window 40. The optical axes OA1 and OA2 of the imaging unit correspond to the optical axis of the observation window 40, and are straight lines that pass through the center of the observation window 40 and extend in the normal direction to the surface of the observation window 40 (hereinafter, the direction indicated by the optical axis of the imaging unit may also be referred to as the "field of view").

[0047] From the viewpoint of reducing the burden on the subject, it is desirable to reduce the diameter of the tip member 36 of the endoscope 1. On the other hand, the endoscopic observation section 110 of the tip member 36 is provided with an imaging section 300 and a stand unit 400. The imaging section 300 includes components such as a lens barrel 302 having an observation window 40, a holder, and a signal cable. The stand unit 400 also includes a mechanism for erecting the stand 70. In other words, the range within the endoscopic observation section 110 where the imaging section 300 and the stand unit 400 are fastened is large, and space is limited, making it difficult to achieve a thinner diameter.

[0048] Under these circumstances, in order to accommodate the need for a thinner diameter, it is conceivable to move the imaging unit 300 closer to the stand unit 400. However, since the imaging unit 300 and the stand unit 400 interfere with each other, the imaging unit 300 is placed at a position P1 away from the stand unit 400.

[0049] An endoscopic image 200 acquired through the observation window 40 at position P1 is shown in FIG. 4A. As shown in FIG. 4A, the endoscopic image 200 is displayed on the monitor together with a mask 202 surrounding the endoscopic image 200. If the endoscopic image 200 is divided into a first quadrant 200A, a second quadrant 200B, a third quadrant 200C, and a fourth quadrant 200D in the horizontal (LH) and vertical (LV) directions with respect to the center of the image, the acoustic lens 52 is displayed in the fourth quadrant 200D. However, the displayed acoustic lens 52 and treatment tool 66 are located on the R side (right side) and D side (bottom side) of the fourth quadrant 200D, and are largely hidden by the mask 202, making them difficult for the surgeon to view. This is likely to affect the surgeon's procedure.

[0050] Therefore, the inventors have studied ways to project the acoustic lens 52 in an endoscopic image 200 at a position that is easily visible to the surgeon. As a result, when viewed from the Z direction, a reference line RL is defined as a straight line that passes through the center of the acoustic lens 52 in the X direction and extends in the Y direction (longitudinal axis direction). The present invention was arrived at by disposing the imaging unit 300 at a position P2 offset from the reference line RL toward the X(-) direction, and tilting the optical axis OA2 of the imaging unit 300 relative to the reference line RL so that the optical axis OA2 intersects with the reference line RL. The reference line RL is an example of a reference line in the present invention. The optical axis OA2 is an example of an optical axis in the present invention.

[0051] IVB in FIG. 4 shows the endoscopic image 200 acquired through the observation window 40 at position P2. The acoustic lens 52 can be positioned on the L side (left side) and D side (lower side) of the fourth quadrant 200D of the endoscopic image 200. The surgeon can easily see the acoustic lens 52 and the treatment tool 66 because they are not hidden by the mask 202. In addition, because the acoustic lens 52 is positioned in the center of the entire endoscopic image 200 and on the D side (lower side), it is easy to grasp the insertion direction. This allows the surgeon to perform the procedure more reliably.

[0052] <Embodiment> The specific configuration of the tip member 36 of the endoscope 1 of this embodiment will be described below. Fig. 5 is a diagram showing the positional relationship between the imaging unit 300, the erector unit 400, and the acoustic lens 52 in the tip member 36, as viewed from the Z(+) direction. Fig. 6 is a side view of the imaging unit 300, as viewed from the X(-) direction. Fig. 7 is a perspective view of the imaging unit 300 and the erector unit 400, as viewed from the Y(+) direction. Fig. 8 is a diagram showing an endoscopic image 200. Fig. 9 is a diagram showing the inside of the endoscopic observation unit 110, as viewed from the Y(-) direction.

[0053] 5, the distal end member 36 has an ultrasonic observation section 100 and an endoscopic observation section 110 on the Y(-) direction side (proximal end side) of the ultrasonic observation section 100. The ultrasonic observation section 100 has an acoustic lens 52 that covers the ultrasonic transducer 50. The endoscopic observation section 110 also has an imaging section 300 and a stand unit 400.

[0054] First, the imaging unit 300 will be described. As shown in FIG. 5 and FIG. 6 , the imaging unit 300 includes, in order from the Y(+) direction side to the Y(-) direction side, a lens barrel 302 including an observation window 40, a large-diameter portion 304, and a signal cable 306. The lens barrel 302 is a cylindrical member whose width in the X direction is narrower than the large-diameter portion 304 (described later), and contains an imaging lens for capturing an image of an object to be observed. The configuration of the imaging lens is not particularly limited. The large-diameter portion 304 is a portion whose width in the X direction is wider than the lens barrel 302, and contains a prism, a solid-state imaging element, and a circuit board. The signal cable 306 is electrically connected to the solid-state imaging element via the circuit board. The signal cable 306 is, for example, configured by bundling multiple signal lines and is flexible. The imaging unit 300 is positioned offset toward the X(-) direction with respect to the reference line RL. In other words, when viewed from the Z(+) direction side, the imaging unit 300 and the reference line RL do not overlap.

[0055] 5 and 6, the endoscopic observation unit 110 has a holder 308 that houses the imaging unit 300. The holder 308 houses and protects the lens barrel 302, the large-diameter portion 304, and the signal cable 306. The holder 308 may house the lens barrel 302, the large-diameter portion 304, and part of the signal cable 306.

[0056] Holder 308 is formed, for example, by bending a single elongated metal plate. Holder 308 has, for example, a U-shape in cross section in the XZ plane, with a bottom extending along the Y direction and wall portions extending from both edges of the bottom toward the Z(+) direction. When viewed from the X(-) direction, holder 308 extends along thick-diameter portion 304 and signal cable 306 and has a bent portion 310. Holder 308 is an example of an imaging unit housing of the present invention.

[0057] Next, the raising platform unit 400 will be described. As shown in FIGS. 5 and 7, the raising platform unit 400 is located on the X(+) direction side of the imaging unit 300 when viewed from the Z(+) direction side. The raising platform unit 400 has a raising platform 70 and a case member 402. The raising platform 70 is rotatably mounted on the case member 402. The case member 402 has a side wall 404, and a lever 410 to which an operation wire 412 is connected is housed in the side wall 404. The lever 410 and the raising platform 70 are connected via a rotation shaft 72. The lever 410 rotates the raising platform 70 around the rotation shaft 72 in response to operation of the raising operation lever 18.

[0058] The elevator housing space 61 of the elevator housing section 60 is defined by a case member 402. The case member 402 is provided with a treatment tool outlet 62 that communicates with the elevator housing space 61. A first duct member 406 and a second duct member 408 that form a treatment tool insertion channel are provided on the Y(-) direction side (base end side) of the case member 402. The Y(+) direction side (distal end side) end of the second duct member 408 is externally fitted to the Y(-) direction side (base end side) end of the first duct member 406, thereby connecting the two. As a result, the second duct member 408 communicates with the treatment tool outlet 62 via the first duct member 406. The elevator housing space 61, the elevator unit 400, and the case member 402 are examples of the space portion, the elevator unit, and the case member of the present invention.

[0059] Next, the operation of this embodiment will be described. As shown in Fig. 5, when viewed from the Z(+) direction, the optical axis OA2 of the imaging unit 300 is tilted toward the reference line RL, and the optical axis OA2 intersects with the reference line RL. In this example, the intersection IP of the optical axis OA2 and the reference line RL is located closer to the Y(+) direction than the acoustic lens 52 (toward the tip in the longitudinal direction).

[0060] FIG. 8 shows an endoscopic image 200 acquired when the intersection point IP is located on the Y(+) direction side of the acoustic lens 52. The acoustic lens 52 is displayed in the endoscopic image 200. With this configuration, the center C of the acoustic lens 52 can be reliably displayed in the fourth quadrant 200D. If the center C of the acoustic lens 52 can be displayed in the fourth quadrant 200D, the surgeon can confirm the acoustic lens 52 and the treatment tool 66 (not shown), allowing for more reliable performance of the procedure. It is sufficient that the center C of the acoustic lens 52 is located in the fourth quadrant 200D; it is not necessary for the entire ultrasonic observation unit 100 to be located in the fourth quadrant 200D. Here, the center C of the acoustic lens 52 is the center position of the acoustic lens 52 displayed on the endoscopic image 200, as shown in FIG. 8. The center C is an example of the center of the acoustic lens of the present invention.

[0061] The angle θ between the optical axis OA2 and the reference line RL is preferably 5 degrees or less (see FIG. 5). By setting the angle θ to 5 degrees or less, it is possible to reduce the deviation between the insertion direction of the tip portion 34 and the field of view direction of the imaging unit 300. This allows the surgeon to easily grasp the insertion direction of the tip portion 34.

[0062] 5, when viewed from the Z(+) direction side, the holder 308 and the stand unit 400 are arranged in a position where at least a portion of the holder 308 overlaps with the stand unit 400 in the Y direction. This allows the imaging section 300 and the stand unit 400 to be arranged close to each other, as shown in Fig. 5, and the width of the endoscopic observation section 110 in the X direction can be narrowed, thereby enabling the diameter of the tip member 36 to be reduced.

[0063] As shown in Fig. 9, the imaging unit 300 and the stand unit 400 are arranged close to each other in the endoscopic observation section 110. Here, only the barrel 302 and the large-diameter portion 304 of the imaging unit 300 are shown. When viewed from the Z(+) direction, the optical axis OA2 of the imaging unit 300 is tilted toward the reference line RL of the acoustic lens 52 (see Fig. 5), so the barrel 302, which is the small-diameter portion, can be arranged close to the case member 402, and the large-diameter portion 304 can be arranged at a distance from the case member 402. As a result, the imaging unit 300 and the stand unit 400 can be arranged close to each other while avoiding interference between them, which makes it possible to reduce the diameter of the endoscopic observation section 110.

[0064] The ultrasonic endoscope according to this embodiment has been described above, but the present invention may be improved or modified in several ways without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0065] 1. Ultrasound endoscope 10 Control section 12 Insertion section 14 Universal Code 16 Angle knob 18 Standing operation lever 20 Air and water supply button 22 Suction button 24 Treatment tool introduction port 30 Soft part 32 Curved section 34 Tip 36 Tip member 36A Lighting window arrangement surface 36B Lighting window arrangement surface 36C Observation window arrangement surface 36D Nozzle arrangement surface 40 Observation window 42A Lighting window 42B Lighting window 44 Air and water supply nozzle 46 Aperture 50 Ultrasonic Transducer 52 Acoustic Lens 54 Housing 60 Standing platform storage area 62 Treatment tool outlet 66 Treatment tools 70 Standing platform 70B Treatment tool guide surface 72 Rotating shaft 100 Ultrasound observation section 110 Endoscopic observation section 112 Main body member 120 Balloon Groove 200 endoscopic images 200A 1st quadrant 200B 2nd quadrant 200C 3rd quadrant 200D 4th quadrant 202 Mask 300 Imaging unit 302 Lens barrel 304 Large diameter part 306 Signal Cable 308 Holder 400 Standing Unit 402 Case material 404 Side wall 406 First Pipe Member 408 Second Pipe Member 410 Lever 412 Control wire C Central Section IP Crossroads OA1 optical axis OA2 optical axis P1 position P2 position RL baseline

Claims

1. a distal end portion disposed at a distal end side of the insertion portion extending along the longitudinal axis; an ultrasonic transducer provided at the tip portion and configured to emit ultrasonic waves toward one side in a first direction perpendicular to the longitudinal axis direction; an acoustic lens provided on the outer surface of the ultrasonic transducer; an imaging unit disposed closer to a base end in the longitudinal axis direction than the acoustic lens; Equipped with When viewed from the first direction, when a straight line that passes through a center of the acoustic lens in the longitudinal axis direction and in a second direction perpendicular to the first direction and extends in the longitudinal axis direction is set as a reference line, When viewed from the first direction, the imaging unit is disposed at a position offset from the reference line to one side in the second direction, and an optical axis of the imaging unit intersects with the reference line. Ultrasound endoscope.

2. an intersection of the optical axis and the reference line is located on a distal end side of the acoustic lens in the longitudinal axis direction; The ultrasonic endoscope according to claim 1 .

3. an image acquired by the imaging unit is divided into four quadrants in the horizontal and vertical directions based on the center of the image, and the center of the acoustic lens is located in the fourth quadrant; 3. The ultrasonic endoscope according to claim 1.

4. The angle between the optical axis and the reference line is 5 degrees or less.

3. The ultrasonic endoscope according to claim 1.

5. the tip end portion has a stand unit arranged at a position overlapping with the imaging unit in the longitudinal axis direction, The stand unit includes a stand that is rotatable around a rotation axis along the second direction, and a case member that defines a space that accommodates the stand. The ultrasonic endoscope according to claim 1 .

6. When viewed from the first direction, at least a part of the imaging unit is disposed at a position overlapping the stand unit. The ultrasonic endoscope according to claim 5 .

Images