Visual anorectal endoscope for anorectal surgery
By designing an adjustable-diameter anorectal endoscope, the diameter of the sliding rod is adjusted using a worm gear, worm wheel, and gear mechanism, and equipped with a lubrication mechanism. This solves the problem of sacrificing both examination effectiveness and comfort caused by a fixed endoscope diameter, achieving flexible adjustment and lubrication, and improving examination efficiency and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-09
- Publication Date
- 2026-03-27
AI Technical Summary
The diameter of the existing anorectal endoscope is fixed, which cannot be flexibly adjusted according to the individual anatomical differences of the patient. It is difficult to balance the examination effect and the patient's comfort. Moreover, changing instruments is time-consuming and increases the risk of infection.
An adjustable-diameter anorectal endoscope was designed, in which the diameter of the sliding rod is adjusted by a worm gear, worm wheel and gear mechanism, and equipped with a lubrication mechanism to reduce friction, including a lubricant delivery system, to achieve adaptive insertion to the patient's anus.
It enables flexible adjustment of the endoscope diameter according to individual anatomical differences of patients, improving examination results and patient comfort, and reducing the time for changing instruments and the risk of infection.
Smart Images

Figure CN121730728A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of anorectal endoscopy technology, and more particularly to a visual anorectal endoscope for anorectal surgery. Background Technology
[0002] In modern anorectal surgery, the anoscope is an indispensable core diagnostic and treatment device. The anoscope can directly display real-time, high-definition, magnified images of the inside of the anus and rectum on the screen, which facilitates doctors to conduct examinations and diagnoses in order to develop reasonable treatment plans.
[0003] In actual use, anoscopes need to be inserted into the patient's anus for examination. The diameter of the endoscope is usually fixed and cannot be flexibly adjusted according to the individual anatomical differences of the patient. Due to significant individual differences in the patient's anal sphincter tension, hemorrhoid severity, tissue laxity, and tolerance, a uniform and fixed diameter often makes it difficult to balance the examination effect and the patient's comfort. Currently, the only clinical solution is to change to different models of instruments, but changing them during the operation is time-consuming and increases the risk of infection. Summary of the Invention
[0004] In view of this, the present invention provides a visual anorectal endoscope for anorectal surgery, which can overcome the shortcomings of the fact that the diameter of the endoscope tube is usually fixed and cannot be flexibly adjusted according to the individual anatomical differences of the patient, and that a uniform fixed diameter often makes it difficult to balance the examination effect and the patient's comfort.
[0005] The technical solution of the present invention is as follows: a visual anorectal endoscope for anorectal surgery, comprising an installation ring, a connecting ring, a sliding rod, a first flexible plate, a second flexible plate, a support ring, an adjustment mechanism, and a sealing mechanism. The installation ring is connected to the connecting ring, which has eight arc-shaped grooves evenly spaced around its circumference. A sliding rod is slidably connected to each arc-shaped groove, and a first flexible plate is connected to each sliding rod. A second flexible plate is slidably connected to each first flexible plate. The second flexible plate is connected to the sliding rod, and the sliding rod, the first flexible plate, and the second flexible plate form an octagonal object. This octagonal object is used to be inserted into the patient's anus for examination. The left end of the sliding rod is inclined in a direction that brings them closer together. A support ring is slidably connected between the inclined positions of the sliding rod. The adjustment mechanism is used to adjust the diameter of the octagonal object formed by the sliding rod, the first flexible plate, and the second flexible plate. There is a gap between the left sides of the first flexible plate, and the sealing mechanism is used to block the gap between the left sides of the first flexible plate.
[0006] Furthermore, it is particularly preferred that the adjusting mechanism includes a worm gear, a worm, a gear ring, a gear, and a rotating plate. The worm gear and the gear ring are rotatably connected to the outside of the mounting ring, and the worm gear and the gear ring are connected. The worm is rotatably connected to the connecting ring, and the worm and the worm gear mesh. Eight gears are rotatably connected to the connecting ring at even intervals in the circumferential direction, and the gears mesh with the gear ring. Each gear is connected to a rotating plate, and the rotating plate is rotatably connected to a sliding rod.
[0007] Furthermore, it is particularly preferred that the sealing mechanism includes a connecting rod, a sealing head, and a pushing assembly. The connecting rod is connected to a sealing head for blocking the gap between the left sides of the first flexible plate. The pushing assembly is used to push the sealing head to the left so that the sealing head adapts to the diameter change of the octagonal object composed of the sliding rod, the first flexible plate, and the second flexible plate.
[0008] Furthermore, it is particularly preferred that the pushing assembly includes a circular block, a circular cover, a sleeve, a circular slider, and a spring. The circular block is connected to the mounting ring, and the circular cover is fitted onto the mounting ring. The circular cover has an L-shaped groove, and the circular block is located in the L-shaped groove to fix the circular cover to the mounting ring. The sleeve is connected to the circular cover, and the circular slider is slidably connected inside the sleeve. The connecting rod slides through the left side of the sleeve and is connected to the circular slider. A spring connects the circular slider and the circular cover.
[0009] Furthermore, it is particularly preferred that the device also includes a lubrication mechanism, which includes an outlet pipe, an annular pipe, a flexible hose, an inlet pipe, and a sealing assembly. The first flexible plate has outlet holes evenly spaced apart. The sliding rod is hollow and each sliding rod is connected to an outlet pipe. The outlet pipe is connected to the second flexible plate. Each outlet pipe has an outlet corresponding to an outlet hole. An annular pipe is connected to a connecting ring. Each sliding rod is connected to a flexible hose, which is connected to and communicates with the annular pipe. The bottom of the annular pipe is connected to an inlet pipe. The sealing assembly is used to block the outlet pipe.
[0010] Furthermore, it is particularly preferred that the sealing assembly includes a silicone plug, a push block, and a silicone block. Each sliding rod is connected to a silicone plug for blocking the outlet pipe. The silicone plug is located inside the outlet pipe. Each sliding rod is slidably connected to a push block, which contacts the silicone plug. Each sliding rod is connected to a silicone block, which is located inside the silicone block.
[0011] Furthermore, it is particularly preferred that the device also includes a hand-held block, which is connected to the annular tube.
[0012] Furthermore, it is particularly preferred that the outer edge of the circular cap has a raised ring.
[0013] Compared with the prior art, the present invention has the following advantages: 1. This invention allows the sliding rod to move away from each other by rotating the worm gear. The first and second soft plates move, and the diameter of the octagonal object formed by the sliding rod, the first soft plate, and the second soft plate gradually increases. This can be flexibly adjusted according to the individual anatomical differences of the patient, thereby balancing the examination effect and the patient's comfort. Furthermore, it eliminates the need to replace other instruments and reduces the risk of infection.
[0014] 2. The lubricant can be introduced into the outlet tube through the inlet tube, ring tube, hose and sliding rod. The lubricant flows out through the outlet and outlet hole to lubricate and reduce friction, so that the octagonal object composed of the sliding rod, the first soft plate and the second soft plate can be better inserted into the patient's anus. Attached Figure Description
[0015] Figure 1 This is a three-dimensional structural diagram of the present invention.
[0016] Figure 2 This is a three-dimensional structural diagram of the arc-shaped groove, sliding rod, first flexible plate, and second flexible plate of the present invention.
[0017] Figure 3 This is a three-dimensional structural diagram of the sliding rod and support ring of the present invention.
[0018] Figure 4 This is a three-dimensional structural diagram of the worm gear and gear ring of the present invention.
[0019] Figure 5 This is a three-dimensional structural diagram of the worm gear, gear, and rotating plate of the present invention.
[0020] Figure 6 This is a three-dimensional structural diagram of the sealing mechanism of the present invention.
[0021] Figure 7 This is a cross-sectional view of the sleeve of the present invention.
[0022] Figure 8 This is a three-dimensional structural diagram of the lubrication mechanism of the present invention.
[0023] Figure 9 This is a three-dimensional structural diagram of the first flexible plate and the liquid outlet hole of the present invention.
[0024] Figure 10 This is a three-dimensional structural diagram of the liquid outlet tube and silicone block of the present invention.
[0025] Figure 11 This is a three-dimensional structural diagram of the liquid outlet pipe and liquid outlet of the present invention.
[0026] Figure 12 This is a cross-sectional view of the sliding rod of the present invention.
[0027] Figure 13 For the present invention Figure 12 Enlarged view of section A.
[0028] Figure 14 This is a three-dimensional structural diagram of the handheld block of the present invention.
[0029] In the diagram: 1. Mounting ring, 2. Connecting ring, 3. Arc groove, 4. Sliding rod, 5. First flexible plate, 6. Second flexible plate, 7. Support ring, 81. Worm gear, 82. Worm, 83. Gear ring, 84. Gear, 85. Rotating plate, 91. Connecting rod, 92. Sealing head, 93. Circular block, 94. Circular cover, 95. L-shaped groove, 96. Sleeve, 97. Circular slider, 98. Spring, 101. Liquid outlet, 102. Liquid outlet pipe, 103. Liquid outlet port, 104. Annular pipe, 105. Flexible hose, 106. Liquid inlet pipe, 107. Silicone plug, 108. Pushing block, 109. Silicone block, 11. Handheld block. Detailed Implementation
[0030] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0031] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The technical solutions of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. It should be understood that the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0032] refer to Figures 1-7 A visual anorectal endoscope for anorectal surgery includes a mounting ring 1, a connecting ring 2, a sliding rod 4, a first flexible plate 5, a second flexible plate 6, a support ring 7, an adjustment mechanism, and a sealing mechanism. The mounting ring 1 is connected to the left side of the connecting ring 2. The connecting ring 2 has eight evenly spaced arc-shaped grooves 3 circumferentially spaced. A sliding rod 4 is slidably connected to each arc-shaped groove 3. A first flexible plate 5 is connected to each sliding rod 4, and a second flexible plate 6 is slidably connected to each first flexible plate 5. The second flexible plate 6 is connected to the sliding rod 4. Both the first and second flexible plates 5 and 6 are made of transparent material. The sliding rod 4, the first flexible plate 5, and the second flexible plate 6 form an eight-section... The number of arc-shaped grooves 3 can be set according to the actual situation. The more arc-shaped grooves 3 there are, the more sliding rods 4, first soft plates 5 and second soft plates 6 there are. The object composed of sliding rods 4, first soft plates 5 and second soft plates 6 is closer to a circle. The left end of the sliding rods 4 is inclined towards each other. A support ring 7 is slidably connected between the inclined positions of the sliding rods 4. The adjustment mechanism is used to adjust the diameter of the octagonal object composed of sliding rods 4, first soft plates 5 and second soft plates 6. There is a gap between the left sides of the first soft plates 5. The sealing mechanism is used to block the gap between the left sides of the first soft plates 5.
[0033] refer to Figure 4 and Figure 5 The adjusting mechanism includes a worm gear 81, a worm 82, a gear ring 83, a gear 84, and a rotating plate 85. The worm gear 81 and the gear ring 83 are rotatably connected to the outside of the mounting ring 1. The left side of the worm gear 81 is connected to the right side of the gear ring 83. The worm 82 is rotatably connected to the upper right side of the connecting ring 2. The worm 82 and the worm gear 81 mesh. Eight gears 84 are rotatably connected to the right side of the connecting ring 2 at even intervals around the circumference. The gears 84 mesh with the gear ring 83. A rotating plate 85 is connected to each gear 84. The rotating plate 85 is rotatably connected to the sliding rod 4. The center position of the gear 84 is consistent with the center position of the arc groove 3, ensuring that the rotating plate 85 can drive the sliding rod 4 to rotate.
[0034] refer to Figure 6 and Figure 7 The sealing mechanism includes a connecting rod 91, a sealing head 92, and a pushing assembly. The left end of the connecting rod 91 is connected to the sealing head 92, which is conical and adapted to the inclined position of the sliding rod 4. The pushing assembly is used to push the sealing head 92 to move to the left, so that the sealing head 92 adapts to the diameter change of the octagonal object composed of the sliding rod 4, the first flexible plate 5, and the second flexible plate 6.
[0035] refer to Figure 6 and Figure 7 The pushing component includes a circular block 93, a circular cover 94, a sleeve 96, a circular slider 97, and a spring 98. Circular blocks 93 are evenly spaced around the outer circumference of the mounting ring 1. A circular cover 94 is fitted on the right side of the mounting ring 1. The circular cover 94 has a raised ring around its outer edge to facilitate rotation. L-shaped grooves 95 are evenly spaced around the left side of the circular cover 94. Circular blocks 93 are located within the L-shaped grooves 95. The number of L-shaped grooves 95 and circular blocks 93 is the same. A sleeve 96 is connected to the middle of the left side of the circular cover 94. A circular slider 97 is slidably connected inside the sleeve 96. A connecting rod 91 slides through the left side of the sleeve 96 and connects to the left side of the circular slider 97. A spring 98 is connected between the right side of the circular slider 97 and the left side of the circular cover 94.
[0036] The doctor inserts the sealing head 92 into the octagonal object formed by the sliding rod 4, the first flexible plate 5, and the second flexible plate 6, and blocks the gap between the left sides of the first flexible plate 5 with the sealing head 92 to reduce discomfort when the first flexible plate 5 enters the patient's anus. Then, the circular cover 94 is placed on the mounting ring 1, and the circular block 93 is inserted into the L-shaped groove 95. The circular cover 94 is then rotated to push the circular block 93 deeper into the L-shaped groove 95, and the circular cover 94 is fixed on the mounting ring 1. At this time, the spring 98 is in a compressed state. If it is necessary to increase the diameter of the octagonal object formed by the sliding rod 4, the first flexible plate 5, and the second flexible plate 6, the doctor can rotate the worm gear 82, which drives the worm wheel. Rotation of worm gear 81 drives gear ring 83 to rotate, gear ring 83 drives gear 84 to rotate, gear 84 drives rotating plate 85 to rotate, rotating plate 85 drives sliding rod 4 to move away from each other, causing the first flexible plate 5 and the second flexible plate 6 to move. The diameter of the octagonal object formed by sliding rod 4, first flexible plate 5 and second flexible plate 6 gradually increases, which can be flexibly adjusted according to the individual anatomical differences of the patient, thus balancing examination effect and patient comfort, without the need to change other instruments, reducing the risk of infection. At this time, spring 98 is in a compressed state. Therefore, during the process of sliding rod 4 moving away from each other, due to the action of spring 98... The circular slider 97 will move to the left, which will cause the connecting rod 91 and the sealing head 92 to move to the left, so that the sealing head 92 can adapt to the diameter change of the octagonal object composed of the sliding rod 4, the first flexible plate 5, and the second flexible plate 6. The support ring 7 can support the sliding rod 4 and improve its stability. The support ring 7 is set at the inclined position of the sliding rod 4, so the support ring 7 will also move as the sliding rod 4 moves away from each other. After adjusting the diameter of the octagonal object composed of the sliding rod 4, the first flexible plate 5, and the second flexible plate 6, the doctor inserts the octagonal object composed of the sliding rod 4, the first flexible plate 5, and the second flexible plate 6 into the... The circular cover 94 is inserted into the patient's anus, and then the circular block 93 is moved out from the depth of the L-shaped groove 95 by rotating it in the opposite direction. The circular cover 94 is then removed from the mounting ring 1, and the sealing head 92 is then removed from the octagonal object composed of the sliding rod 4, the first soft plate 5, and the second soft plate 6. Finally, other instruments are placed into the octagonal object composed of the sliding rod 4, the first soft plate 5, and the second soft plate 6 for inspection. The worm gear 81 and the worm 82 have a self-locking function, so after the worm 82 stops rotating, the worm gear 81 will not rotate anymore, and the diameter of the octagonal object composed of the sliding rod 4, the first soft plate 5, and the second soft plate 6 will not decrease, ensuring that the doctor can perform the examination normally.
[0037] refer to Figures 8-13It also includes a lubrication mechanism, which includes a liquid outlet pipe 102, an annular pipe 104, a flexible hose 105, a liquid inlet pipe 106, and a sealing assembly. Liquid outlet holes 101 are evenly spaced on the first flexible plate 5. The sliding rod 4 is hollow and has evenly spaced liquid outlet pipes 102 connected to it. The liquid outlet pipes 102 are connected to the second flexible plate 6. Each liquid outlet pipe 102 has a liquid outlet 103, which corresponds to the liquid outlet hole 101. The liquid outlet 103 is long. The strip shape allows the outlet 103 and outlet hole 101 to maintain their corresponding states when the first flexible plate 5 and the second flexible plate 6 move, so that the lubricant can still flow out through the outlet 103 and outlet hole 101. The connecting ring 2 is connected to the annular tube 104, and the right end of the sliding rod 4 is connected to the flexible hose 105. The flexible hose 105 and the annular tube 104 are connected and communicate with each other. The bottom of the annular tube 104 is connected to the inlet pipe 106. The sealing component is used to block the outlet pipe 102.
[0038] refer to Figure 12 and Figure 13 The sealing assembly includes silicone plugs 107, push blocks 108, and silicone blocks 109. Silicone plugs 107 are evenly spaced inside the sliding rod 4. The silicone plugs 107 are located inside the outlet pipe 102. The end of the silicone plug 107 near the outlet pipe 102 is tapered, which can better block the outlet pipe 102. Push blocks 108 are evenly spaced on the sliding rod 4. The push blocks 108 are in contact with the tapered position of the silicone plugs 107, so the push blocks 108 can push the silicone plugs 107 out of the outlet pipe 102. Silicone blocks 109 are evenly spaced on the sliding rod 4. The push blocks 108 are located inside the silicone blocks 109. The number of silicone plugs 107, push blocks 108, and silicone blocks 109 is the same.
[0039] The doctor inserts an octagonal object, consisting of a sliding rod 4, a first flexible plate 5, and a second flexible plate 6, into the patient's anus. The patient's skin comes into contact with the silicone block 109 and squeezes it. The silicone block 109 then squeezes the pushing block 108, which in turn pushes the silicone plug 107 out of the outlet tube 102, preventing it from blocking the tube. Then, the inlet tube 106 is connected to the lubricant supply line, and the lubricant flows through the inlet tube 106. The annular tube 104, hose 105, and sliding rod 4 flow into the outlet tube 102. Then, the lubricant flows out through the outlet 103 and outlet hole 101 to lubricate and reduce friction, so that the octagonal object composed of the sliding rod 4, the first soft plate 5, and the second soft plate 6 can be better inserted into the patient's anus. The silicone block 109 that does not contact the patient's skin will not be squeezed. The silicone plug 107 corresponding to the silicone block 109 still blocks the outlet tube 102, which can reduce the waste of lubricant.
[0040] refer to Figure 14It also includes a hand-held block 11. The annular tube 104 is connected to the hand-held blocks 11 on both the front and rear sides. The hand-held blocks 11 can better insert the octagonal object composed of the sliding rod 4, the first soft plate 5, and the second soft plate 6 into the patient's anus. The left side of the hand-held block 11 has anti-slip texture to prevent the doctor's hand from slipping.
[0041] Obviously, the embodiments described above are only some embodiments of the present invention, and not all embodiments. They only express the preferred implementation of the present invention and are described in a relatively specific and detailed manner, but should not be construed as limiting the scope of the present invention.
[0042] It should be noted that, for those skilled in the art, various modifications, additions or subtractions, improvements and substitutions can be made without departing from the concept of the present invention. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
Claims
1. A visual anorectal endoscope for anorectal surgery, comprising a mounting ring (1) and a connecting ring (2), wherein the mounting ring (1) is connected to the connecting ring (2), characterized in that: It also includes a sliding rod (4), a first soft plate (5), a second soft plate (6), a support ring (7), an adjustment mechanism, and a sealing mechanism. The connecting ring (2) has eight arc-shaped grooves (3) evenly spaced around its circumference. The sliding rod (4) is slidably connected in each arc-shaped groove (3). The first soft plate (5) is connected to each sliding rod (4). The second soft plate (6) is slidably connected in each first soft plate (5). The second soft plate (6) is connected to the sliding rod (4). The sliding rod (4), the first soft plate (5), and the second soft plate (6) form an octagonal object. This octagonal object is used to be inserted into the patient's anus for examination. The left end of the sliding rod (4) is inclined towards each other. The support ring (7) is slidably connected between the inclined positions of the sliding rod (4). The adjustment mechanism is used to adjust the diameter of the octagonal object formed by the sliding rod (4), the first soft plate (5), and the second soft plate (6). There is a gap between the left sides of the first soft plate (5). The sealing mechanism is used to block the gap between the left sides of the first soft plate (5).
2. The visual anorectal endoscope for anorectal surgery as described in claim 1, characterized in that: The adjustment mechanism includes a worm gear (81), a worm (82), a gear ring (83), a gear (84), and a rotating plate (85). The worm gear (81) and the gear ring (83) are rotatably connected to the outside of the mounting ring (1). The worm gear (81) and the gear ring (83) are connected. The worm (82) is rotatably connected to the connecting ring (2). The worm (82) and the worm gear (81) mesh. Eight gears (84) are rotatably connected to the connecting ring (2) at even intervals in the circumferential direction. The gears (84) mesh with the gear ring (83). The rotating plate (85) is connected to each gear (84). The rotating plate (85) and the sliding rod (4) are rotatably connected.
3. The visual anorectal endoscope for anorectal surgery as described in claim 2, characterized in that: The sealing mechanism includes a connecting rod (91), a sealing head (92), and a pushing assembly. The connecting rod (91) is connected to a sealing head (92) for blocking the gap between the left sides of the first flexible plate (5). The pushing assembly is used to push the sealing head (92) to move to the left so that the sealing head (92) adapts to the diameter change of the octagonal object composed of the sliding rod (4), the first flexible plate (5), and the second flexible plate (6).
4. A visual anorectal endoscope for anorectal surgery as described in claim 3, characterized in that: The pushing assembly includes a circular block (93), a circular cover (94), a sleeve (96), a circular slider (97), and a spring (98). The circular block (93) is connected to the mounting ring (1), and the circular cover (94) is fitted onto the mounting ring (1). The circular cover (94) has an L-shaped groove (95) on it. The circular block (93) is located in the L-shaped groove (95) to fix the circular cover (94) onto the mounting ring (1). The sleeve (96) is connected to the circular cover (94), and the circular slider (97) is slidably connected inside the sleeve (96). The connecting rod (91) slides through the left side of the sleeve (96) and is connected to the circular slider (97). The spring (98) is connected between the circular slider (97) and the circular cover (94).
5. A visual anorectal endoscope for anorectal surgery as described in claim 1, characterized in that: It also includes a lubrication mechanism, which includes an outlet pipe (102), an annular pipe (104), a hose (105), an inlet pipe (106), and a sealing assembly. The first flexible plate (5) has outlet holes (101) evenly spaced apart. The sliding rod (4) is hollow and is connected to the outlet pipe (102). The outlet pipe (102) is connected to the second flexible plate (6). The outlet pipe (102) has an outlet (103) on it. The outlet (103) corresponds to the outlet hole (101). The connecting ring (2) is connected to the annular pipe (104). The sliding rod (4) is connected to the hose (105). The hose (105) is connected to the annular pipe (104). The bottom of the annular pipe (104) is connected to the inlet pipe (106). The sealing assembly is used to block the outlet pipe (102).
6. A visual anorectal endoscope for anorectal surgery as described in claim 5, characterized in that: The sealing assembly includes a silicone plug (107), a push block (108), and a silicone block (109). Each sliding rod (4) is connected to a silicone plug (107) for blocking the outlet pipe (102). The silicone plug (107) is located inside the outlet pipe (102). Each sliding rod (4) is slidably connected to a push block (108), which contacts the silicone plug (107). Each sliding rod (4) is connected to a silicone block (109), and the push block (108) is located inside the silicone block (109).
7. A visual anorectal endoscope for anorectal surgery as described in claim 5, characterized in that: It also includes a hand-held block (11), which is connected to the annular tube (104).
8. A visual anorectal endoscope for anorectal surgery as described in claim 4, characterized in that: The round cap (94) has a raised ring around its outside.