Endoscope hood

Abstract

To provide an endoscope hood that can adjust an appearance imaged on an imaging screen.SOLUTION: An endoscope hood 1 includes: a cylindrical body 10 externally fitted to a tip part of an endoscope; and an inclined plane 17 provided at an inner peripheral surface 16 of the body 10 and gradually approaching an axial center of the body 10 toward a tip side of the body 10. The inclined plane 17 is provided in a position abutting on a corner part of the tip part of the endoscope on one side in a specific direction that is orthogonal to the axial center of the body 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an endoscope hood that is attached to the tip portion of an endoscope. [Background technology]

[0002] Conventionally, endoscopes that are inserted into the digestive tract of the human body to observe the inside and treat lesions may have a hood attached to the tip. Generally, this hood is a cylindrical member made of a flexible material such as silicone rubber, and is fitted over the tip of the endoscope with its tip protruding beyond the tip of the endoscope.

[0003] By attaching such a hood, it is possible to prevent the relatively hard tip of the endoscope from damaging tissue such as the intestinal wall. In addition, a space surrounded by the hood is formed at the tip of the endoscope, ensuring the necessary field of view. Therefore, even when performing procedures such as resecting a lesion using a treatment tool inserted through the forceps port of the endoscope, it is possible to perform the procedure safely.

[0004] In addition, a doctor using the endoscope can easily grasp the amount of the treatment tool protruding from the tip of the endoscope by using the tip of the hood displayed on the imaging screen as an index. This prevents bleeding or perforation caused by the tip of the treatment tool accidentally coming into contact with the intestinal wall, etc., and allows for safe and quick treatment.

[0005] However, in general, in an endoscope, the objective lens of the camera is disposed at a position offset from the axis, and the forceps outlet (the outlet of the forceps channel) is disposed on the opposite side of the axis to the objective lens. Therefore, the hood is displayed offset from the center of the screen on the imaging screen. For this reason, if the opening of the hood tip is set to a relatively large diameter to improve the operability of the treatment tool, the part of the hood tip on the forceps outlet side is not displayed on the imaging screen, which can make it difficult to grasp the amount of protrusion of the treatment tool.

[0006] One possible solution to this problem is to offset the opening at the tip of the hood from the axis (see, for example, Patent Document 1). By offsetting the opening at the tip of the hood toward the objective lens, it becomes possible to capture the entire tip of the hood on the imaging screen, even when the opening has a relatively large diameter. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2011-218212 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the offset amount of the objective lens differs depending on the model of endoscope, and in the method described in Patent Document 1, the offset amount of the opening is fixed, so depending on the model of endoscope, it may not be possible to properly capture the tip of the hood on the imaging screen.

[0009] In other words, the hood becomes less versatile, and it becomes necessary to prepare a dedicated hood for each model of endoscope, which leads to problems such as increased manufacturing costs due to the need to prepare multiple types of molds, and also the trouble for users such as doctors to check whether the hood is compatible with their endoscope.

[0010] In view of the above circumstances, the present invention provides an endoscope hood that is capable of adjusting the way an image is displayed on an imaging screen. [Means for solving the problem]

[0011] The endoscope hood of the present invention is fitted onto the tip of an endoscope. , made of elastic materialand an inclined surface provided on the inner circumferential surface of the body and gradually approaching the axis of the body toward the tip side of the body, the inclined surface being provided only at a position where a corner of the tip of the endoscope abuts on one side of a specific direction perpendicular to the axis of the body, and a recessed portion for accommodating a part of the endoscope being provided on the other side of the inner circumferential surface of the body in the specific direction. The recess is configured such that both circumferential edge portions come into contact with the outer peripheral surface of the endoscope, and the recess is configured as a groove that is continuous in the axial direction of the main body. It is characterized by the above.

[0012] According to the endoscopic hood of the present invention, the endoscopic hood can be tilted relative to the endoscope by abutting the corners of the tip of the endoscope against the inclined surface, thereby offsetting the opening at the tip of the endoscopic hood to one side in a specific direction from the axial center of the endoscope. Furthermore, by adjusting the relative axial positions of the endoscopic hood and the tip of the endoscope, it is possible to adjust the abutment position of the corners of the tip of the endoscope on the inclined surface and adjust the offset amount of the opening at the tip of the endoscopic hood, thereby adjusting the way the endoscopic hood is shown on the image capture screen of the endoscope camera. Furthermore, the recessed portion makes it possible to suppress bending deformation of the endoscopic hood when it is tilted relative to the endoscope, making it easy to attach the endoscopic hood to the endoscope and to adjust the relative axial position. In addition, by configuring the recess so that the edges on both sides in the circumferential direction come into contact with the outer peripheral surface of the endoscope, when the endoscopic hood is tilted relative to the endoscope, the recess can be elastically deformed so as to be pushed wider by the outer peripheral surface of the endoscope, so that the rear end of the endoscopic hood on the recess side can be elastically deformed so as to be drawn toward the axial center. In other words, the amount of radial protrusion at the rear end of the endoscopic hood can be reduced, and the rear end can be less likely to get caught on the intestinal wall or the like. In addition, by configuring the recess as a groove that is continuous in the axial direction of the main body, the elastic deformation of the recess side of the endoscopic hood when tilted relative to the endoscope can be made approximately uniform in the axial direction, making it easy to attach the endoscopic hood to the endoscope and to adjust the relative position in the axial direction. In addition, since the outer peripheral surface of the endoscope and the recess can be brought into contact over an appropriate range in the axial direction, the endoscopic hood in the tilted state can be stably held at the tip of the endoscope.

[0019] In the endoscope hood of the present invention, it is preferable that a notch portion is provided on one side of the rear end of the main body in the specific direction.

[0020] This prevents contact between the rear end of the endoscopic hood on the inclined surface side and the outer peripheral surface of the endoscope, and suppresses bending deformation of the endoscopic hood when it is inclined relative to the endoscope, making it easier to attach the endoscopic hood to the endoscope and to adjust its relative axial position.

[0021] In the endoscope hood of the present invention, it is preferable that the outer peripheral surface of the main body has an uneven shape on the other side in the specific direction, the uneven shape being capable of locking a string-like member.

[0022] According to this, when a traction device or the like having a string-shaped member is attached to the outside of the endoscope by engaging it, the tip of a sheath or the like through which the string-shaped member is inserted can be shielded from the tip side by the inclined endoscope hood, thereby preventing the sheath or the like from getting caught when inserted into the digestive tract or the like. Effect of the Invention

[0023] The endoscope hood of the present invention has the excellent effect of making it possible to adjust the way an image is displayed on an imaging screen. [Brief description of the drawings]

[0024] [Figure 1] 1A and 1B are perspective views of an endoscope hood according to one embodiment of the present invention. [Diagram 2] 1A is a front view of the endoscope hood, and B is a rear view of the endoscope hood. [Diagram 3] 2A is a bottom view of the endoscope hood with the front side facing left, and FIG. [Figure 4] 2A and 2B are cross-sectional views taken along the line II-II and III-III in FIG. 2A. [Diagram 5] 1A and 1B are schematic diagrams showing an endoscope hood attached to an endoscope. [Figure 6] 1A and 1B are schematic diagrams showing an endoscope hood attached to an endoscope. [Figure 7] 1A and 1B are schematic diagrams showing an endoscope hood attached to an endoscope. [Figure 8] 1A to 1C are schematic diagrams showing an image captured by an endoscope camera. [Figure 9] 11A to 11C are schematic diagrams showing a method of using the locking protrusions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0026] 1A and 1B are perspective views of an endoscope hood 1 (hereinafter, hood 1) according to one embodiment of the present invention. FIG. 1A is a perspective view of the hood 1 as viewed from below the front side (tip side), and FIG. 1B is a perspective view of the hood 1 as viewed from above the back side (rear end side). FIG. 2A is a front view of the hood 1, and FIG. 2B is a rear view of the hood 1. FIG. 3A is a bottom view of the hood 1 with the front side facing left, and FIG. 3B is a cross-sectional view taken along line II in FIG. 2A. FIG. 4A is a cross-sectional view taken along line II-II in FIG. 2A, and FIG. 4B is a cross-sectional view taken along line III-III in FIG. 2A.

[0027] The hood 1 is used by being attached to the tip of an endoscope that is inserted into the digestive tract of the human body to observe the inside and treat lesions. More specifically, the hood 1 is fitted onto the tip of the portion of the endoscope that is inserted into the digestive tract. The hood 1 is configured to be attached at an angle to the tip of the endoscope, thereby offsetting the tip opening 1a with respect to the axis of the endoscope.

[0028] The hood 1 includes a cylindrical body 10 having a generally circular tip opening 1a and a rear opening 1b. The body 10 is made of a flexible and transparent (or semi-transparent) elastic material (elastomer), such as silicone rubber or polyvinyl chloride. The tip side of the outer circumferential surface 11 of the body 10 is provided with a tip taper section 11a that gradually reduces in diameter toward the tip side to facilitate insertion of the endoscope into a narrow portion. The rear end side of the outer circumferential surface 11 is also provided with a rear taper section 11b that gradually reduces in diameter toward the rear side to prevent the outer circumferential surface 11 from getting caught on the intestinal wall or the like.

[0029] Leading end surface 12, which is the leading end of hood 1, and rear end surface 13, which is the rear end of hood 1, are surfaces that are perpendicular to the axis C of hood 1 (main body 10). Furthermore, corners 12a, 13a on the outer periphery of leading end surface 12 and rear end surface 13 are provided with a relatively large radius so as to prevent damage to tissues, etc., in the digestive tract when they come into contact with the tissues.

[0030] A cutout portion 14 is provided on one side of the rear end face 13 in a specific direction perpendicular to the axis C (in this embodiment, the upper side in the vertical direction). This cutout portion 14 is a portion for avoiding interference with the endoscope when the hood 1 is inclined with respect to the tip of the endoscope. The cutout portion 14 is provided by partially cutting (recessing) the rear end face 13 toward the tip side, and is configured to have a shape that presents a parabolic outline in a plan view. Note that in this embodiment, the cutout portion 14 is provided on the rear end face 13 so as to occupy a range of approximately 90° in the circumferential direction (around the axis C).

[0031] The outer peripheral surface 11 is also provided with a locking protrusion 15 that protrudes toward the outer peripheral side. This locking protrusion 15 is for locking a string-like member that is inserted into the digestive tract or the like in association with the endoscope. The locking protrusion 15 is configured in a curved rectangular plate shape with the circumferential direction as the longitudinal direction. In addition, the side surface 15a on the tip side of the locking protrusion 15 is the surface that comes into contact with the string-like member, and is curved with a parabolic outline with the tip side being convex when viewed from the bottom.

[0032] The inner peripheral surface 16 of the main body 10 is provided with a constant diameter portion 16a at the tip end side, which has a substantially constant inner diameter along the axial direction, and an expanded diameter portion 16b at the rear end side, which has an inner diameter larger than that of the constant diameter portion 16a. The constant diameter portion 16a is a portion that is fitted to the endoscope at the rear end side, and a portion that forms a space surrounded by the hood 1 at the tip end side. The constant diameter portion 16a is provided over a range of approximately 3 / 4 of the total length of the hood 1 in the axial direction. The expanded diameter portion 16b is a portion for providing a gap between the outer peripheral surface of the endoscope, and is provided over a range of approximately 1 / 4 of the total length of the hood 1 in the axial direction.

[0033] A plurality of (in this embodiment, nine) contact protrusions 16c are provided on the rear end side of the constant diameter portion 16a. The contact protrusions 16c are configured as curved elongated rectangular plates with the circumferential direction as the longitudinal direction, and the top surface 16c1 is the contact surface that comes into contact with the outer circumferential surface of the endoscope. The inner diameter of the top surface 16c1 of the constant diameter portion 16a is set to be approximately the same as or slightly smaller than the outer diameter of the tip of the corresponding endoscope.

[0034] That is, in this embodiment, the inner surface of the constant diameter portion 16a is not entirely in contact with the outer surface of the endoscope, but is only partially in contact at the top surface 16c1 of the contact convex portion 16c, thereby providing an appropriate engagement force without impeding insertability.

[0035] The constant diameter portion 16a is also provided with a plurality of drainage grooves 16d (four in this embodiment) configured in a kamaboko shape. The drainage grooves 16d are for draining water discharged from the water supply nozzle of the endoscope so that the water does not accumulate in the space surrounded by the tip side of the constant diameter portion 16a of the hood 1 and the tip surface of the endoscope.

[0036] The drain groove 16d is provided so as to continue along the axial direction from a position about 1 / 4 of the total length of the hood 1 from the distal end surface 12 to the rear end of the constant diameter portion 16a, and communicates with the inside of the expanded diameter portion 16b. In addition, a drain hole 16e penetrating in the thickness direction of the main body 10 is provided at a position slightly toward the rear end from the middle portion of the drain groove 16d. Therefore, water in the space surrounded by the distal side of the constant diameter portion 16a and the distal end surface of the endoscope is discharged from the drain groove 16d to the outside of the hood 1 via the expanded diameter portion 16b or the drain hole 16e. In addition, each drain groove 16d is evenly arranged in the circumferential direction.

[0037] Furthermore, constant diameter portion 16a is provided with an inclined surface 17 that is inclined so as to gradually approach axis C toward the tip side. This inclined surface 17 is intended to incline hood 1 relative to the endoscope by abutting against a corner of the tip of the endoscope. Inclined surface 17 is provided so as to partially protrude constant diameter portion 16a on one side in a specific direction (in this embodiment, the upper side in the vertical direction).

[0038] Specifically, the inclined surface 17 is composed of a top surface 16f1 of the inclined protruding portion 16f that is curved in the circumferential direction and has a triangular prism shape. Therefore, the inclined surface 17 is curved along the circumferential direction. The inclined surface 17 is provided from a position slightly toward the tip side of the middle part of the hood 1 in the axial direction over about 1 / 4 of the total length of the hood 1. The inclined surface 17 is provided so as to occupy a range of about 69° in the circumferential direction. The rear end of the inclined surface 17 is continuous with the top surface 16c1 of one of the contact protruding portions 16c. The other ends of the inclined surface 17 are rounded and are continuous with the side surfaces 16f2 to 16f4 of the adjacent inclined protruding portions 16f.

[0039] The inner circumferential surface 16 of the main body 10 is also provided with a semi-cylindrical recess 18 that continues in the axial direction on the other side in the specific direction (in this embodiment, the lower side in the vertical direction). This recess 18 is a portion for accommodating a part of the endoscope when the hood 1 is inclined with respect to the tip of the endoscope. The recess 18 is configured as a groove that continues in the axial direction from the tip surface 12 to the rear end surface 13, i.e., over the entire length of the hood 1. In this embodiment, the thickness of the expanded diameter portion 16b is partially made equal to the thickness of the constant diameter portion 16a on the other side in the specific direction, so that the recess 18 reaches the rear end surface 13.

[0040] The bottom surface 18a of the recess 18 is curved to have a parabolic contour in a cross section perpendicular to the axial direction. The recess 18 is also provided to occupy a range of approximately 66° in the circumferential direction. As a result, the edges 18b, 18c on both sides of the circumferential direction of the recess 18 are positioned so that they can come into contact with the outer circumferential surface of the endoscope.

[0041] The contact protrusions 16c, the inclined surfaces 17 (inclined protrusions 16f), and the recesses 18 are arranged between the drainage grooves 16d in the circumferential direction. The contact protrusions 16c are arranged at three locations where no recesses 18 are provided, with three of each at approximately equal intervals in the axial direction. The inclined protrusions 16f are provided integrally with the contact protrusions 16c located at the most distal end on one side in the specific direction.

[0042] Figures 5A and B, 6A and B, and 7A and B are schematic diagrams showing a state in which the hood 1 is attached to the endoscope 100. Figures 5A, 6A, and 7A are cross-sectional views corresponding to the cross-sectional view taken along line II in Figure 2A. Figures 5B, 6B, and 7B are views of the hood 1 and the endoscope 100 as viewed from the tip side.

[0043] The endoscope 100 in this example is provided with, on its distal end surface 101, a camera objective lens 110, a forceps outlet 111 which is an outlet for treatment tools, an air / water nozzle 112 for cleaning the objective lens 110, an auxiliary water outlet 113 for cleaning diseased areas, etc., and two light guides 114 for illumination. The objective lens 110 is disposed offset from the axis C1 of the endoscope toward the outer periphery, and the forceps outlet 111 is disposed on the opposite side of the objective lens 110 across the axis C1.

[0044] 5A and 5B, the hood 1 is attached by inserting the tip of the endoscope 100 into the hood 1 from the rear end opening 1b. At this time, the inclined surface 17 (inclined convex portion 16f) is arranged on the same side as the objective lens 110 with respect to the axis C1 of the endoscope 100.

[0045] When the tip of the endoscope 100 is inserted into the hood 1, the top surface 16c1 of the contact protrusion 16c comes into contact with and engages with the outer circumferential surface 102 of the endoscope 100. As a result, the axis C of the hood 1 and the axis C1 of the tip of the endoscope 100 are approximately aligned. When the endoscope 100 is further pushed toward the tip from this state, the corner 103 at the tip of the endoscope 100 comes into contact with the inclined surface 17. Then, when the endoscope 100 is further pushed toward the tip with the corner 103 in contact with the inclined surface 17, the hood 1 is inclined with respect to the axis C1 of the endoscope 100, and the tip opening 1a can be offset from the axis C1 of the endoscope 100 toward the objective lens 110.

[0046] 6A and 6B show a state in which the corner 103 of the endoscope 100 is in contact with the inclined surface 17 at a substantially midpoint in the axial direction. When the corner 103 comes into contact with the inclined surface 17, the inclined surface 17 is pressed by the corner 103 and moves together with the tip side of the hood 1 in a direction away from the axis C of the endoscope 100. As a result, the hood 1 is inclined with respect to the axis C1 of the endoscope 100, and the tip opening 1a is offset from the axis C1 of the endoscope 100 toward the inclined surface 17.

[0047] Therefore, by arranging the inclined surface 17 on the same side as the objective lens 110 with respect to the axis C1 of the endoscope 100, the axis C at the tip of the hood 1 can be brought close to the optical center of the objective lens 110. This makes it possible to show the entire tip opening 1a on the imaging screen of the camera equipped in the endoscope 100.

[0048] In addition, since the top surface 16c1 of the contact protrusion 16c is engaged with the outer peripheral surface 102 of the endoscope 100, the hood 1 does not simply tilt, but tilts in an elastically deformed state. In this embodiment, the elastic deformation of the hood 1 is adjusted by providing the cutout portion 14 and the recessed portion 18.

[0049] Specifically, notch 14 prevents contact between the rear end of hood 1 and outer peripheral surface 102 of the endoscope, and a portion of the tip of endoscope 100 opposite inclined surface 17 is housed in recess 18 to prevent bending deformation of hood 1 relative to axis C. Furthermore, recess 18 is configured as a groove that continues over the entire length of hood 1, making elastic deformation on the recess 18 side of hood 1 approximately uniform in the axial direction and preventing localized deformation.

[0050] 7A and B show a state in which endoscope 100 is pushed further toward the tip side from the state shown in Figures 6A and B, and corner portion 103 of endoscope 100 is brought into contact with approximately the most extreme position of inclined surface 17. In this state, the inclination of hood 1 is greater than in the state shown in Figures 6A and B, and the offset amount of tip opening 1a is also greater than in the state shown in Figures 6A and B.

[0051] That is, in this embodiment, the hood 1 is tilted by the abutment of the corner 103 and the inclined surface 17, so that it is possible to arbitrarily adjust the offset amount of the tip opening 1a by adjusting the contact position between the corner 103 and the inclined surface 17, i.e., by adjusting the axial position of the hood 1 relative to the endoscope 100. Also, as described above, in this embodiment, the cutout portion 14 and the recessed portion 18 suppress elastic deformation of the hood 1 in the inclined state, so that the axial position of the hood 1 can be easily and smoothly adjusted.

[0052] Furthermore, in this embodiment, the recess 18 is configured as a groove that continues in the axial direction, and is configured so that the outer peripheral surface 102 of the endoscope 100 abuts against the edges 18b, 18c on both sides of the recess 18 when the inclination of the hood 1 becomes large, thereby reducing the amount of radial protrusion at the rear end of the hood 1.

[0053] Specifically, the outer peripheral surface 102 of the endoscope 100 comes into contact with the edges 18b, 18c on both sides of the recess 18, and the hood 1 is elastically deformed to expand the recess 18, so that the rear end portion of the hood 1 opposite the inclined surface 17 is drawn toward the axis C. This makes it possible to suppress the radial protrusion of the rear end portion of the hood 1, which increases as the inclination of the hood 1 increases, and to reduce the occurrence of snagging by the hood 1 that would hinder the operation of the endoscope 100.

[0054] Furthermore, by forming the recess 18 in the form of a groove that is continuous in the axial direction, it becomes possible to bring the recess 18 into contact with the outer circumferential surface 102 of the endoscope 100 over an appropriate range in the axial direction. This makes it possible to stably hold the hood 1 at the tip of the endoscope 100 even in an inclined state.

[0055] For ease of understanding, Figures 6A and 6B depict the hood 1 in a state where it is not elastically deformed. Also, Figures 7A and 7B depict the hood 1 in a state where it is elastically deformed, but the deformed state of the hood 1 is not necessarily accurate.

[0056] 8A to 8C are schematic diagrams showing the image captured by the camera of endoscope 100. Of these, Fig. 8A shows the image captured in the state shown in Figs. 5A and B. As described above, objective lens 110 of the camera is disposed offset from axis C1 of endoscope 100, so that when axis C of hood 1 approximately coincides with axis C1 of the tip of endoscope 100, tip opening 1a of hood 1 is imaged at a position shifted from the center of the captured image.

[0057] A user of the endoscope 100, such as a doctor, can adjust the projected position of the tip opening 1a by shifting the position of the hood 1 in the axial direction while referring to the image screen. In this example, by moving the hood 1 toward the rear end side from the state shown in Fig. 8A, the projected position of the tip opening 1a can be moved toward the center of the image screen.

[0058] Then, by disposing the hood 1 at an appropriate axial position, the tip opening 1a is entirely displayed on the imaging screen, as shown in Fig. 8B or C. By displaying the tip opening 1a entirely on the imaging screen in this manner, the user of the endoscope 100 can easily grasp the protrusion amount of each treatment tool 120 from the imaging screen.

[0059] For example, in the state shown in Fig. 8B, the treatment tool 120 protrudes beyond the distal end surface 12 of the hood 1, and therefore, if the distal end of the endoscope 100 is moved in this state, there is a possibility that tissues in the digestive tract may be damaged. On the other hand, in the state shown in Fig. 8C, the treatment tool 120 is housed within the hood 1, and therefore, the distal end of the endoscope 100 can be moved safely.

[0060] In addition, the hood 1 is highly versatile because the offset amount of the tip opening 1a can be adjusted by adjusting the relative position in the axial direction. That is, as long as the outer diameter of the tip of the endoscope 100 is an outer diameter that can fit the hood 1, the hood 1 can properly project the tip opening 1a on the imaging screen regardless of the difference in the position of the objective lens 110 depending on the model.

[0061] 9 is a schematic diagram showing a method of using the locking protrusion 15. Since an endoscope 100 is generally provided with only one forceps channel, for example, a traction tool 200 for tractioning a lesion to secure a visual field when resecting the lesion with a high-frequency knife or the like in endoscopic submucosal dissection (ESD) is locked to the outside of the endoscope 100 and inserted into the digestive tract together with the endoscope 100. The locking protrusion 15 is for locking a string-like member 201 of the traction tool 200.

[0062] 9, the traction tool 200 includes a string-like member 201 and a sheath 202 through which the string-like member is inserted so as to be freely advanced and retreated. The string-like member 201 has an intermediate portion protruding from the tip of the sheath 202 to form a loop-shaped (ring-shaped) retaining ring 201a. This retaining ring 201a is a portion that is retained by a clip or the like that grips a lesion or the like, and its size can be changed by advancing and retreating the string-like member 201 relative to the sheath 202 with an operating portion (not shown) on the rear end side of the traction tool 200.

[0063] The towing tool 200 is fixed to the endoscope 100 by inserting the hood 1 into the locking ring 201a, then retracting the string-like member 201 relative to the sheath 202 and appropriately fastening the hood 1 with the locking ring 201a. At this time, by locating the tip of the sheath 202 on the rear end side of the hood 1 and locking the locking ring 201a on the side surface 15a on the tip side of the locking protrusion 15, it is possible to prevent the locking ring 201a from slipping and ensure stable locking.

[0064] In this embodiment, the locking protrusion 15 is provided on the opposite side of the inclined surface 17, so that the sheath 202 is disposed on the inclined surface 17 side. This makes it possible to shield the tip of the sheath 202 from the tip side by the inclined hood 1, and therefore makes it possible to prevent the tip of the sheath 202 from getting caught on tissues, etc. in the digestive tract when the tip part of the endoscope 100 is moved toward the tip side.

[0065] In this manner, in this embodiment, the inclination of the hood 1 is effectively utilized by devising an arrangement of the locking protrusions 15, thereby preventing the tip of the towing tool 200 accompanying the endoscope 100 from getting caught. Insertion of the endoscope 100 accompanied by the towing tool 200 into the digestive tract or the like is more difficult than when the endoscope 100 is inserted alone, but according to this embodiment, even the endoscope 100 accompanied by the towing tool 200 can be easily and safely inserted into the digestive tract or the like.

[0066] In addition, instead of the locking protrusions 15, for example, groove-shaped locking recesses may be provided, and a part of the locking ring 201a may be accommodated and locked in the locking recesses. The shape and number of the locking protrusions 15 or locking recesses are not particularly limited, and any appropriate uneven shape may be adopted. The locking protrusions 15 or locking recesses may be used to lock a treatment tool other than the towing tool 200. It goes without saying that the locking protrusions 15 or locking recesses may be omitted when it is not necessary to attach the towing tool 200 or the like.

[0067] Although an embodiment of the present invention has been described above, the endoscope hood of the present invention is not limited to the above-described embodiment, and various modifications can of course be made without departing from the gist of the present invention. For example, the shapes and arrangements of the components of the hood 1 are not limited to those shown in the above-described embodiment, and various known shapes and arrangements can be adopted.

[0068] Furthermore, the actions and effects shown in the above-described embodiments are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to these. [Explanation of symbols]

[0069] 1 Endoscope hood 10 Main unit 14 Cutout 15 Locking protrusion 16 Inner surface 17 Slope 18 Recess 18b, 18c Edge of recess 100 Endoscope 102 Outer surface of endoscope 103 Corner of the tip of an endoscope C Axis of endoscope hood (main body)

Claims

1. a cylindrical main body made of an elastic material and fitted onto the tip of the endoscope; a slope provided on an inner circumferential surface of the main body and gradually approaching an axis of the main body toward a tip side of the main body; the inclined surface is provided only at a position where a corner of the tip of the endoscope abuts on one side of a specific direction perpendicular to an axis of the main body, a recess provided on the inner circumferential surface of the main body on the other side of the specific direction and configured to accommodate a part of the endoscope; The recess is configured such that both edge portions in a circumferential direction come into contact with an outer circumferential surface of the endoscope, The recess is configured as a groove that is continuous in the axial direction of the main body. A hood for an endoscope.

2. The endoscope hood according to claim 1, An endoscope hood comprising: a rear end of said main body, said rear end including a notch on one side in said specific direction.

3. The endoscope hood according to claim 1 or 2, An endoscope hood, comprising: an outer peripheral surface of the main body, the outer peripheral surface being provided on the other side in the specific direction, the outer peripheral surface having an uneven shape capable of engaging a string-shaped member.

Images