An angle-adjustable interventional puncture auxiliary support
By designing an adjustable-angle interventional puncture auxiliary stent, precise adjustment and locking of interventional puncture were achieved, solving the problem of individual differences caused by reliance on experience in existing technologies, and improving the safety and standardization of the surgery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SECOND MEDICAL CENT OF CHINESE PLA GENERAL HOSPITAL
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-05
AI Technical Summary
In current interventional puncture procedures, the puncture angle, depth, and needle trajectory depend on the operator's experience, resulting in large individual differences and low accuracy. It is difficult to achieve accurate repeatability and review of surgical plans, and there is a lack of real-time feedback and quantitative methods, which affects the safety of the surgery and the standardization of training.
An adjustable-angle interventional puncture auxiliary stent was designed, comprising a slide rail, a slider, an adjustment mechanism, and a puncture mechanism. It achieves precise adjustment and locking in three-dimensional space through linear and circumferential components, and provides visual path calibration with a laser light, simplifying the locking operation.
It improves the accuracy and repeatability of punctures, reduces the risk of accidental injury, enhances the standardization and teaching value of the surgery, simplifies the operation process, and adapts to the needs of various interventional devices and surgeries.
Smart Images
Figure CN122140335A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of puncture-assisted stent technology, and more specifically, to an adjustable-angle interventional puncture-assisted stent. Background Technology
[0002] In existing technologies, interventional puncture procedures (such as deep vein catheterization, tissue biopsy, or ablation needle puncture) still heavily rely on the operator's manual operation. The puncture angle, depth, and needle trajectory are mainly controlled in real time by the operator's personal experience, spatial judgment, and tactile sense. This approach has significant individual differences and subjective uncertainties. First, manual operation makes it difficult to maintain a stable and precise posture of the puncture needle in three-dimensional space, especially when it is necessary to avoid complex anatomical areas such as important blood vessels, nerves, or organs. The inherent physiological tremors and unintentional displacement of the human hand can easily cause deviations in the puncture path at the micrometer to millimeter level, which is often unacceptable in delicate interventional procedures. Second, existing technologies lack the means to quantify and record key puncture parameters (especially the needle angle) in real time and objectively. Angle setting often relies on visual estimation or rough estimation with a simple protractor, which not only has limited accuracy but also cannot provide real-time feedback or constraints during the procedure. This results in low standardization of the operation process and makes it difficult to achieve precise repeatability and post-operative review and analysis of the surgical plan.
[0003] The aforementioned technical limitations have had a multifaceted negative impact on clinical practice. On the one hand, the instability of the operation and the unquantifiable parameters directly affect the success rate and accuracy of the puncture, potentially requiring multiple attempts to reach the target location. This not only prolongs the operation time and increases patient suffering and infection risks, but also poses a greater risk of complications such as vascular injury, pneumothorax, and bleeding when the puncture target is small or adjacent to sensitive structures, threatening patient safety. On the other hand, the highly reliance on the operator's experience hinders the standardized training and promotion of interventional puncture techniques, resulting in a steep learning curve for young physicians. Furthermore, differences in technical levels between different medical institutions or operators can lead to inconsistent treatment quality for patients. In addition, while the target can be observed through imaging equipment in the increasingly popular image-guided interventional therapy, its precision advantage cannot be fully utilized without auxiliary devices to accurately translate the pre-planned path into a stable physical needle insertion. Therefore, developing an interventional puncture auxiliary stent that can provide stable support, achieve precise setting and quantification of the puncture angle, and coordinate with the image-guided system is of urgent and important clinical significance for improving surgical safety, repeatability, and promoting technical standardization. Summary of the Invention
[0004] (a) Technical problems to be solved To address the problems existing in the prior art, the present invention provides an adjustable-angle interventional puncture auxiliary stent to solve the technical problems mentioned in the background art.
[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: an adjustable-angle interventional puncture auxiliary stent, comprising a slide rail and two sliders that are slidably connected to the slide rail, and further comprising an adjustment mechanism and a puncture mechanism; The adjustment mechanism includes a linear component and a circumferential component. The adjustment mechanism can adjust the angle of the puncture needle in three-dimensional space, adjust it to the corresponding position according to different puncture requirements and fix it, thus ensuring the accuracy of puncture. The linear component allows the entire unit to be adjusted in both the horizontal and vertical directions, and can be fixed within the adjustable range, thereby ensuring the effectiveness of use. The circumferential component ensures that the overall angle can be adjusted in the circumferential direction, thereby producing the optimal puncture angle and improving the accuracy of puncture. The puncture mechanism can not only indicate the puncture location, but also adapt to different puncture needles according to different puncture needs, thereby improving adaptability.
[0006] Preferably, the linear assembly includes an inner sleeve and a reverse sleeve mounted on the two sliders, the inner sleeve and the reverse sleeve being vertically arranged, and a transverse rod being slidably connected inside each inner sleeve, with the two transverse rods respectively abutting against the side wall of the slide rail.
[0007] Preferably, a bidirectional rod is threaded between the two reverse sleeves, and each of the two bidirectional rods has a rounded end, with the two rounded ends abutting against the transverse rod.
[0008] Preferably, a vertical rod is installed on each of the two sliders, a stop sleeve is slidably sleeved on each of the two vertical rods, and a lifting plate is installed between the two stop sleeves. The lifting plate and the slider can be in a vertical sliding state by the limiting of the stop sleeves and the vertical rods.
[0009] Preferably, the two stop sleeves are provided with multiple rubber rings at equal intervals on one side close to the inner wall of each other, the other side of the stop sleeve forms a smooth surface, and multiple stop grooves are provided at equal intervals on the side wall of the vertical rod, and the rubber rings are slidably connected to the side wall of the vertical rod.
[0010] Preferably, the circumferential assembly includes a circular rod mounted on the lifting plate, the circular rod being slidably connected to a follower sleeve at its upper limit, and the inner wall of the follower sleeve being slidably connected to a circular ring at its upper limit.
[0011] Preferably, the follower sleeve has an internal hole, and a threaded sleeve is threaded into the internal hole. A compression spring is provided at the lower end of the threaded sleeve, and a bottom plate is connected to the compression spring. The bottom plate abuts against the side wall of the circular rod, and the other end of the bottom plate is inserted into the threaded sleeve.
[0012] Preferably, the threaded sleeve has a top plate that slides coaxially through the circular ring, the lower end of the top plate pressing on the circular ring, and a push spring coaxially connected to the threaded sleeve, one end of the push spring abutting against the top plate and the other end of the push spring abutting against the threaded sleeve, and the threaded sleeve has a handle.
[0013] Preferably, the puncture mechanism includes an intermediate sleeve mounted on the circular ring, with multiple telescopic rods slidably connected within the intermediate sleeve, and double-sided sleeves mounted at both ends of the multiple telescopic rods, with a central sleeve mounted within each of the double-sided sleeves.
[0014] Preferably, rubber edges are installed on the two double-sided sleeves respectively, an insert block is installed inside one of the double-sided sleeves, the rubber edge is stuck on the insert block, a laser light is provided on the insert block, the laser light is sleeved inside the central sleeve, and a matching sleeve is threaded inside the other double-sided sleeve.
[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides an adjustable-angle interventional puncture auxiliary stent, which has the following beneficial effects: This invention achieves simultaneous and rapid locking of multiple spatial degrees of freedom through a mechanical linkage locking design, improving the efficiency and reliability of intraoperative adjustment and fixation. The bidirectional rod in the linear component drives two sliders to move towards each other through reverse threads, which can simultaneously complete the lateral locking by the lateral rod pressing against the slide rail and the vertical locking by the vertical rod squeezing the rubber ring inside the stop sleeve to generate huge static friction. The threaded sleeve in the circumferential component can simultaneously drive the bottom plate to press the circular rod to lock the front and rear positions with a single rotation, and drive the top plate to press the circular ring through the push spring to lock the tilt angle. This combined locking mechanism simplifies the complex multi-step locking into two intuitive rotation operations, greatly shortening the preoperative preparation time and ensuring the stability of all degrees of freedom at the moment of puncture.
[0016] This invention provides an intuitive and precise visual calibration method for planning and setting puncture paths. In the puncture mechanism, the laser lamp, central sleeve, and matching sleeve are strictly coaxially set. The laser beam emitted can accurately indicate the preset extension line of the puncture needle and form a clear light spot on the body surface. The operator can intuitively adjust the various degrees of freedom of the support until the light spot coincides with the target point by observing the relationship between the position of the light spot and the target puncture point. Thus, the precise spatial alignment of the path can be completed before needle insertion. This design transforms the abstract puncture angle and position parameters into visible optical guidance, reduces the reliance on the operator's spatial imagination ability, and greatly improves the accuracy and repeatability of path planning.
[0017] This invention features excellent ease of operation and ergonomic design. All adjustment and locking functions are achieved through manual mechanical operation, requiring no external power supply or complex settings. The sliding of the linear component, the raising and lowering of the lifting plate, and the sliding of the follower sleeve and the rotation of the circular ring of the circumferential component are all smooth and effortless. The introduction of the laser lamp makes the fine-tuning process more reliable, and the combined locking mechanism simplifies the fixing operation to the extreme. This makes the adjustment, calibration and locking process of the entire support smooth and efficient, significantly reducing the operator's operational burden and psychological pressure. It is especially beneficial for quickly establishing an accurate puncture channel in a tense surgical environment.
[0018] The structural design of this invention has broad clinical adaptability and flexibility. Its slide rail can be easily installed on the edge of various standard operating tables, providing a stable foundation for the stent. The matching sleeve in the puncture mechanism can be replaced according to different specifications of puncture needles, biopsy needles or catheters, ensuring compatibility with a variety of interventional devices. The multi-degree-of-freedom independent adjustment capability allows the stent to adapt to different surgical needs from superficial punctures to deep organ interventions, and can flexibly respond to differences in patient position and anatomical structure changes, providing a universal and precise auxiliary platform for interventional operations in various clinical departments.
[0019] This invention fundamentally improves the safety, standardization, and educational value of interventional puncture surgery by providing stable, quantifiable, and repeatable mechanical constraints. Its robust locking mechanism effectively suppresses hand tremors and unintentional displacement, ensuring that the puncture needle advances precisely along the preset path, reducing the risk of accidental injury to blood vessels, nerves, and surrounding organs. All angle and position parameters can be set and maintained through the mechanical structure of the stent itself, enabling the surgical plan to be executed precisely and accurately recorded and reviewed. This not only helps to standardize surgical procedures and unify treatment standards, but also provides an ideal practical aid for the standardized training of young physicians. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the overall structure of an adjustable-angle interventional puncture auxiliary stent according to the present invention; Figure 2 In this invention Figure 1 A schematic diagram of the side structure; Figure 3 This is an exploded cross-sectional view of the lifting plate and slider in this invention; Figure 4 This is an exploded cross-sectional view of the stop sleeve and slider in this invention; Figure 5 This is a schematic diagram of the structure of the follower sleeve and the intermediate sleeve in this invention; Figure 6 This is a cross-sectional view of the follower sleeve in this invention; Figure 7 This is an exploded cross-sectional view of the follower sleeve and the screw sleeve in this invention; Figure 8 This is a schematic diagram of the circular ring and screw in this invention; Figure 9 This is a schematic diagram of the structure of the embedded block and the matching sleeve in this invention.
[0021] In the diagram: 11. Slide rail; 12. Slider; 21. Linear assembly; 22. Inner sleeve; 23. Reverse sleeve; 24. Horizontal rod; 25. Bidirectional rod; 26. Round head; 27. Vertical rod; 28. Stop sleeve; 29. Lifting plate; 31. Circumferential assembly; 32. Circular rod; 33. Follower sleeve; 34. Circular ring; 35. Inner hole; 36. Screw sleeve; 37. Compression spring; 38. Bottom plate; 39. Top plate; 41. Puncture mechanism; 42. Intermediate sleeve; 43. Telescopic rod; 44. Double-sided sleeve; 45. Center sleeve; 46. Rubber edge; 47. Embedded block; 48. Laser light; 49. Matching sleeve; 210. Rubber ring; 211. Smooth surface; 212. Stop groove; 310. Push spring; 311. Handle. Detailed Implementation
[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0023] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0024] In this invention, unless otherwise stated, the directional terms such as "up" and "down" generally refer to the directions shown in the accompanying drawings, or to the vertical, perpendicular, or gravitational direction; similarly, for ease of understanding and description, "left" and "right" generally refer to the left and right shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.
[0025] Please see Figures 1 to 9This embodiment aims to solve the technical problems of poor stability, inability to quantify and fix angles, and high dependence on the surgeon's experience in manual puncture operation. By integrating a mechanical mechanism that can be adjusted and locked in combination in three-dimensional space with multiple degrees of freedom, it provides stable support and precise angle guidance for the puncture needle, thereby achieving accurate planning, quantitative setting and reliable execution of the puncture path, and improving the standardization and safety of the surgery.
[0026] The interventional puncture auxiliary support includes a slide rail 11 as the mounting base and two sliders 12 that can be independently limited and slidably connected thereon. It also includes an adjustment mechanism for achieving precise adjustment of the three-dimensional spatial angle and a puncture mechanism 41 for installing and guiding the puncture needle. The adjustment mechanism is further composed of a linear component 21 for achieving linear adjustment and locking in the lateral and vertical directions and a circumferential component 31 for achieving circumferential angle adjustment and locking.
[0027] The linear assembly 21 includes an inner sleeve 22 and a reverse sleeve 23, which are respectively vertically mounted on two sliders 12. A transverse rod 24 is slidably passed through the inner sleeve 22 and its end can abut against the side wall of the slide rail 11 to achieve transverse locking. A bidirectional rod 25 is connected between the two reverse sleeves 23 by a reverse thread. The round heads 26 at both ends of the bidirectional rod 25 can tighten or loosen the transverse rod 24 as it rotates. A vertical rod 27 is also fixed on the two sliders 12. A stop sleeve 28 is slidably sleeved on the vertical rod 27. A lifting plate 29 is fixedly connected between the two stop sleeves 28. Multiple rubber rings 210 are evenly spaced on the inner side of the stop sleeve 28, while its outer side is a smooth surface 211. Multiple stop grooves 212 are correspondingly opened on the side wall of the vertical rod 27 for the rubber rings 210 to contact and generate frictional locking force.
[0028] The circumferential assembly 31 includes a circular rod 32 fixed on the lifting plate 29. The upper limit of the circular rod 32 is slidably connected to a follower sleeve 33. The upper limit of the inner wall of the follower sleeve 33 is slidably connected to a circular ring 34. The follower sleeve 33 has an internal hole 35. The internal hole 35 is threadedly connected to a threaded sleeve 36. The lower end of the threaded sleeve 36 is connected to a bottom plate 38 through a compression spring 37. The bottom plate 38 can be pressed against the surface of the circular rod 32. A top plate 39 is slidably mounted on the threaded sleeve 36. The lower end of the top plate 39 can be pressed against the upper surface of the circular ring 34. A push spring 310 is also mounted on the threaded sleeve 36. The two ends of the push spring 310 abut against the shoulders of the top plate 39 and the threaded sleeve 36, respectively. The upper end of the threaded sleeve 36 is provided with a handle 311 for rotation operation.
[0029] The puncture mechanism 41 includes an intermediate sleeve 42 fixedly installed on a circular ring 34. Multiple telescopic rods 43 are axially damped and slidably connected inside the intermediate sleeve 42. Both ends of all the telescopic rods 43 are connected to two double-sided sleeves 44. A central sleeve 45 is fixedly installed inside each double-sided sleeve 44. Rubber edges 46 are embedded at the ends of both double-sided sleeves 44. An insert block 47 is installed inside one double-sided sleeve 44 and is clamped and fixed by the rubber edge 46. A laser lamp 48 is installed on the insert block 47 and the optical axis of the laser lamp 48 is coaxial with the central sleeve 45. A fitting sleeve 49 for adapting puncture needles of different specifications is threadedly connected inside the double-sided sleeve 44 on the other side.
[0030] The workflow and adjustment and fixation principle are as follows: During use, the slide rail 11 is always fixed next to the operating table. The patient's position and the approximate position of the support are determined according to the puncture site. Then, fine adjustment with multiple degrees of freedom is performed. First, select the matching sleeve 49 that matches the puncture needle specification and screw it into one side of the double sleeve 44. Then, install the embedded block 47 with laser light 48 on the other side. Turn on the laser light 48, and the beam emitted by it will pass through the center of the coaxial matching sleeve 49 and be projected onto the patient's body surface to form a light spot, which serves as a visual reference for path calibration.
[0031] One-dimensional coarse adjustment in the horizontal direction (along the slide rail 11) can be performed by manually pushing the slider 12. The vertical height can be adjusted by moving the lifting plate 29 up and down. The front and rear position of the puncture point (second linear degree of freedom) can be adjusted by sliding the follower sleeve 33 along the circular rod 32. The tilt angle of the puncture needle can be adjusted by rotating the circular ring 34. When the laser spot indicator has reached the predetermined ideal puncture path, all adjustment degrees of freedom need to be locked.
[0032] The locking operation is efficiently completed through two combined locking mechanisms. Rotating the bidirectional rod 25 causes the reverse threads at both ends to drive the two sliders 12 to move closer to each other. This process simultaneously achieves two actions: First, the round heads 26 at both ends press against their respective transverse rods 24, forcing the ends of the transverse rods 24 to press tightly against the side wall of the slide rail 11, thereby locking the transverse movement; Second, the opposing movement of the two sliders 12 drives the two vertical rods 27 to move closer to each other synchronously, squeezing the multiple rubber rings 210 inside the stop sleeve 28, causing them to generate a huge static friction force with the stop grooves 212 on the side wall of the vertical rods 27, thereby locking the height in the vertical direction. This design achieves the simultaneous locking of the transverse and vertical linear degrees of freedom with only one operation (rotating the bidirectional rod 25).
[0033] Subsequently, by rotating the handle 311, the screw sleeve 36 is screwed into the inner hole 35. The downward movement of the screw sleeve 36 increases the normal pressure of the bottom plate 38 on the surface of the circular rod 32 through the compression spring 37, thereby increasing the sliding friction between the follower sleeve 33 and the circular rod 32 to lock the front and rear positions. On the other hand, the downward movement of the screw sleeve 36 pushes the top plate 39 downward to press the circular ring 34 through the push spring 310, thereby increasing the friction between the circular ring 34 and the inner wall of the follower sleeve 33 to lock the tilt angle. This design enables the simultaneous locking of two rotational degrees of freedom in the circumferential direction with only one operation (rotating the screw sleeve 36).
[0034] Once all degrees of freedom are locked, the puncture path is completely fixed. At this point, the telescopic rod 43 can be slid along the axis, and the end with the matching sleeve 49 can be gently brought close to the patient's skin puncture point. The operator stabilizes the support with one hand and smoothly inserts the puncture needle through the central hole of the matching sleeve 49 along the set angle and path with the other hand, thus completing the precise puncture operation.
[0035] Working principle summary: This invention integrates adjustment and locking functions of multiple degrees of freedom into a small number of operating parts through ingenious mechanical linkage design, achieving rapid, synchronous and stable posture fixation. Combined with coaxial laser indication, it provides visual calibration of the puncture path, providing stable, accurate and user-friendly auxiliary support for interventional puncture surgery, effectively reducing the difficulty of operation and improving the standardization of surgery.
[0036] Of all the solutions mentioned above, those involving the connection between two components can be selected according to the actual situation, such as welding, bolt and nut connection, bolt or screw connection, or other known connection methods, which will not be elaborated here. For all the fixed connections mentioned above, welding is preferred. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An adjustable-angle interventional puncture support, comprising a slide rail (11) and two sliders (12) slidably connected to the slide rail (11), characterized in that: It also includes adjustment mechanisms and puncture mechanisms (41); The adjustment mechanism includes a linear component (21) and a circumferential component (31). The adjustment mechanism can adjust the angle of the puncture needle in three-dimensional space, adjust it to the corresponding position according to different puncture requirements and fix it, thus ensuring the accuracy of puncture. The linear component (21) allows the whole to be adjusted in the horizontal and vertical directions and can be fixed within the adjustable range, thereby ensuring the effect of use; The circumferential component (31) ensures that the whole can be angularly adjusted in the circumferential direction, so that it can produce the best puncture angle and improve the accuracy of puncture. The puncture mechanism (41) can not only indicate the puncture position, but also adapt to different puncture needles according to different puncture needs, thereby improving adaptability.
2. The adjustable-angle interventional puncture auxiliary stent according to claim 1, characterized in that: The linear assembly (21) includes an inner sleeve (22) and a reverse sleeve (23) mounted on the two sliders (12). The inner sleeve (22) and the reverse sleeve (23) are vertically arranged. A transverse rod (24) is slidably connected inside each inner sleeve (22). The two transverse rods (24) abut against the side wall of the slide rail (11).
3. The adjustable-angle interventional puncture auxiliary stent according to claim 2, characterized in that: Two reverse sleeves (23) are respectively connected by a two-way rod (25) with reverse threads, and the two ends of the two-way rod (25) are respectively provided with round heads (26), and the two round heads (26) respectively abut against the transverse rod (24).
4. The adjustable-angle interventional puncture auxiliary stent according to claim 3, characterized in that: Vertical rods (27) are installed on the two sliders (12) respectively, and stop sleeves (28) are slidably sleeved on the two vertical rods (27) respectively. A lifting plate (29) is installed between the two stop sleeves (28). The lifting plate (29) and sliders (12) can be in a vertical sliding state by the limiting of the stop sleeves (28) and the vertical rods (27).
5. An adjustable-angle interventional puncture support according to claim 4, characterized in that: The two stop sleeves (28) are provided with multiple rubber rings (210) at equal intervals on one side of their inner walls, and a smooth surface (211) is formed on the other side of the stop sleeves (28). Multiple stop grooves (212) are provided at equal intervals on the side wall of the vertical rod (27), and the rubber rings (210) are slidably connected to the side wall of the vertical rod (27).
6. The adjustable-angle interventional puncture auxiliary stent according to claim 4, characterized in that: The circumferential component (31) includes a circular rod (32) mounted on the lifting plate (29), the circular rod (32) being slidably connected to a follower sleeve (33) at its upper limit, and the inner wall of the follower sleeve (33) being slidably connected to a circular ring (34) at its upper limit.
7. An adjustable-angle interventional puncture support according to claim 6, characterized in that: The follower sleeve (33) has an internal hole (35) and a threaded sleeve (36) is threaded into the internal hole (35). A compression spring (37) is provided at the lower end of the threaded sleeve (36). A bottom plate (38) is connected to the compression spring (37). The bottom plate (38) abuts against the side wall of the circular rod (32), and the other end of the bottom plate (38) is inserted into the threaded sleeve (36).
8. An adjustable-angle interventional puncture auxiliary stent according to claim 7, characterized in that: The threaded sleeve (36) passes through the circular ring (34) and is slidably provided with a top plate (39). The lower end of the top plate (39) presses on the circular ring (34), and a push spring (310) is coaxially sleeved on the threaded sleeve (36). One end of the push spring (310) abuts against the top plate (39), and the other end of the push spring (310) abuts against the threaded sleeve (36). The threaded sleeve (36) is provided with a handle (311).
9. An adjustable-angle interventional puncture auxiliary stent according to claim 6, characterized in that: The puncture mechanism (41) includes an intermediate sleeve (42) mounted on the circular ring (34). Multiple telescopic rods (43) are connected in a damped sliding manner inside the intermediate sleeve (42), and double-sided sleeves (44) are respectively installed at both ends of the multiple telescopic rods (43). A central sleeve (45) is installed inside each double-sided sleeve (44).
10. An adjustable-angle interventional puncture auxiliary stent according to claim 9, characterized in that: Rubber edges (46) are installed on the two double-sided sleeves (44) respectively. An insert block (47) is installed inside one of the double-sided sleeves (44). The rubber edge (46) is stuck on the insert block (47). A laser lamp (48) is provided on the insert block (47). The laser lamp (48) is sleeved inside the central sleeve (45). A matching sleeve (49) is threaded inside the double-sided sleeve (44) on the other side.