A double-layer coupling limiter

Abstract

The utility model provides a kind of double-layer coupling beam limiter, comprising: base;Blade assembly, including diaphragm blade assembly and shutter blade assembly, diaphragm blade assembly and shutter blade assembly are layered along the ray beam direction arrangement;Drive unit, including the diaphragm drive unit for driving diaphragm blade assembly and the shutter drive unit for driving shutter blade assembly, diaphragm drive unit and shutter drive unit are rotatably coaxially arranged on base by bearing assembly;Driving motor, it is set on base, and it is engaged connection by motor gear and drive unit;Diaphragm blade assembly is installed on diaphragm drive unit by first guide structure, shutter blade assembly is installed on shutter drive unit by second guide structure, seamless integration general rectangular field imaging and special narrow beam imaging two functions in the same beam limiter are realized, double-layer structure design makes that beam limiter can be adjusted irradiation field shape according to different clinical needs, effectively reduce unnecessary radiation exposure.

Description

Technical Field

[0001] This utility model relates to the field of beam limiter technology, specifically to a double-layer coupled beam limiter. Background Technology

[0002] In the field of medical radiology equipment, C-arm X-ray machines are usually equipped with a beam limiter (collimator), which limits the shape and size of the X-ray beam by adjusting the position of the internal blades, so as to precisely control the radiation range within the area required for diagnosis, thereby protecting the patient's non-target tissues and improving image quality.

[0003] Current C-arm collimators generally adopt a single-layer, multi-blade structure, forming a rectangular field of view through the translational movement of the blades. This structure basically meets the requirements for conventional fluoroscopy and angiography, but it does not meet the special shape requirements of long bones and other special parts when performing full-length imaging. In order to cover long and narrow anatomical structures, the single-layer rectangular collimator must open a large rectangular field, causing a large amount of radiation to irradiate the air and human tissue outside the target area. This not only increases the unnecessary radiation dose, but also degrades the image quality due to the increased scattered radiation.

[0004] In existing technologies, to obtain a non-rectangular irradiation field, sometimes an external collimator or an extremely complex multi-degree-of-freedom blade drive mechanism is used. The former increases preoperative preparation time and operational steps, compromising the mobility and smoothness of operation of the C-arm device; the latter makes the internal structure of the collimator exceptionally complex, increasing the number of parts, resulting in its large size and high cost. Furthermore, the complex transmission chain introduces higher mechanical errors and jamming risks, affecting the reliability and lifespan of the equipment. In addition, traditional collimator structures have design flaws in blade guidance and drive. Common guiding mechanisms are prone to asynchronous blade movement, asymmetrical opening, or even jamming due to machining errors or accumulated assembly errors. The fit between the turntable and the base is often complex, making it difficult to ensure that all moving parts have a stable and uniform reference, affecting the accuracy of irradiation field control and long-term stability.

[0005] In summary, existing beam limiters suffer from problems such as limited functionality, poor adaptability, complex structure, and unreliable reliability. Therefore, there is an urgent need for a novel beam limiter structure that is compact, reliable in operation, and can integrate general imaging and dedicated narrow-beam imaging functions.

[0006] Therefore, the existing technology still needs further development. Utility Model Content

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a dual-layer coupling beam limiter to solve the problems existing in the prior art.

[0008] To achieve the above technical objectives, this utility model provides a dual-layer coupling beam limiter, comprising: a base; The blade assembly includes an aperture blade assembly and a shutter blade assembly, wherein the aperture blade assembly and the shutter blade assembly are arranged in layers along the beam emission direction; The driving unit includes an aperture driving unit for driving the aperture blade assembly and a shutter driving unit for driving the shutter blade assembly. Both the aperture driving unit and the shutter driving unit are rotatably coaxially mounted on the base via a bearing assembly. A drive motor is mounted on the base, and the drive motor is connected to the drive unit via a motor gear to drive the drive unit to rotate. The aperture blade assembly is mounted on the aperture drive unit via a first guide structure, and the shutter blade assembly is mounted on the shutter drive unit via a second guide structure.

[0009] Specifically, the aperture driving unit includes a first aperture turntable and a second aperture turntable, which are rotatably coaxially mounted on the base.

[0010] Specifically, the shutter drive unit includes a first shutter dial and a second shutter dial, which are rotatably coaxially mounted on the base.

[0011] Specifically, the aperture blade assembly includes multiple aperture blades, and the first guide structure includes a guide limiting pin disposed on one side of the aperture blade and a drive pin disposed on the other side of the aperture blade.

[0012] Specifically, the first-layer aperture turntable is provided with a first guide groove, and the second-layer aperture turntable is provided with a second guide groove; The guide pin of the aperture blade is slidably accommodated in the first guide groove of the first layer aperture turntable; The drive pin of the aperture blade is slidably housed in the second guide groove of the second layer aperture turntable.

[0013] Specifically, the aperture blade assembly includes four aperture blades, each aperture blade is arc-shaped, each aperture blade has two guide pins on one side and a drive pin on the other side, and the aperture blades overlap each other to form a single-layer opening and closing aperture blade assembly.

[0014] Specifically, the shutter blade assembly includes a plurality of shutter blades, and the second guide structure includes a shutter guide pin disposed on the shutter blades; The first-layer shutter turntable is provided with a concave guide groove, and the shutter guide pin of the shutter blade is slidably accommodated in the concave guide groove; The second-layer shutter turntable is provided with a guide rail, and the shutter blades are mounted on the guide rail via guide seats.

[0015] Specifically, the shutter blade assembly includes two shutter blades, each of which is sickle-shaped. Each shutter blade is provided with a shutter guide pin. The first-layer shutter turntable is provided with two parallel concave guide grooves. The shutter guide pins of the two shutter blades are respectively housed in the two concave guide grooves. The two shutter blades are arranged in the same layer to form a single-layer opening and closing shutter blade assembly.

[0016] Specifically, a circular boss is provided on one side of the concave guide groove to limit the axial displacement of the shutter blade assembly; The second-layer shutter dial is provided with two limiting bosses, which are arranged in parallel, and each of the two limiting bosses is equipped with a guide rail.

[0017] Specifically, the dual-layer coupling limiter includes a pressure plate, which is fixedly connected to the base. A boss is provided on the side of the first-layer aperture turntable facing the pressure plate, and the pressure plate is sleeved on the outside of the boss to restrict the axial and radial movement of the first-layer aperture turntable.

[0018] Specifically, the dual-layer coupling beam limiter also includes a photoelectric switch unit, which is fixedly mounted on the base and used to detect the initial positions of the aperture drive unit and the shutter drive unit.

[0019] Specifically, the photoelectric switch unit includes a first photoelectric switch and a second photoelectric switch; The first photoelectric switch is used to detect the initial position of the first layer aperture turntable, and the second photoelectric switch is used to detect the initial position of the second layer aperture turntable.

[0020] Specifically, the dual-layer coupling limiter includes a blocking plate, which is disposed on the first-layer aperture turntable; The distance between the first layer aperture turntable at its extreme position under its limiting structure and the light column of the first photoelectric switch is less than or equal to the length of the shielding plate; The distance between the second-layer aperture turntable at its extreme position under its limiting structure and the light column of the second photoelectric switch is less than or equal to the length of the shielding plate.

[0021] Specifically, the dual-layer coupling limiter also includes a drive motor, which is fixedly mounted on the base; The drive motor includes an aperture drive motor and a shutter drive motor. The aperture drive motor is used to drive the aperture drive unit to rotate, and the shutter drive motor is used to drive the shutter drive unit to rotate. The aperture drive motor includes a first-layer aperture turntable drive motor and a second-layer aperture turntable drive motor, and the shutter drive motor includes a first-layer shutter turntable drive motor and a second-layer shutter turntable drive motor.

[0022] Beneficial effects: This invention provides a dual-layer coupling beam limiter. By arranging the aperture and shutter blade assemblies in layers along the beam exit direction and coaxially integrating their drive units on the same base via bearing assemblies, and employing a direct drive method via gear meshing of the drive motor, a highly integrated dual-layer coupling beam limiter structure is constructed. This achieves seamless integration of two core functions—general rectangular field imaging and dedicated narrow-beam imaging—within the same beam limiting device. The dual-layer structure design allows the beam limiter to flexibly adjust the irradiation field shape according to different clinical needs, effectively reducing unnecessary radiation exposure. It satisfies both conventional rectangular imaging and narrow-beam imaging of special areas such as long bones, further improving the ease of use of C-arm and other equipment in complex surgeries. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the composition structure of the double-layer coupling beam limiter provided in a specific embodiment of this utility model; Figure 2 This is a schematic diagram of the assembly structure of the double-layer coupling beam limiter provided in a specific embodiment of this utility model; Figure 3 This is a schematic diagram of the opening and closing process of the aperture blades provided in a specific embodiment of this utility model; Figure 4 This is a schematic diagram of the shutter blade opening and closing process provided in a specific embodiment of the present invention; Figure 5 This is a schematic diagram of the shutter blade rotation process provided in a specific embodiment of this utility model; Figure 6 This is a schematic diagram of the aperture blade rotation process provided in a specific embodiment of this utility model; The above figures include the following reference numerals: 1. Base; 2. Aperture blade assembly; 3. Shutter blade assembly; 4. First-layer aperture turntable; 5. Second-layer aperture turntable; 6. First-layer shutter turntable; 7. Second-layer shutter turntable; 8. Shutter guide pin; 9. Guide rail; 10. Guide seat; 11. Pressure plate; 12. First photoelectric switch; 13. Second photoelectric switch; 14. Shielding plate; 15. First-layer aperture turntable drive motor; 16. Second-layer aperture turntable drive motor; 17. First-layer shutter turntable drive motor; 18. Second-layer shutter turntable drive motor; 19. First bearing; 20. Second bearing; 21. Third bearing; 22. First motor gear; 23. Second motor gear; 24. Third motor gear; 25. Fourth motor gear. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the creation of this utility model.

[0025] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0026] Please see Figure 1 - Figure 6 This embodiment provides a dual-layer coupling beam limiter, including a base 1, a blade assembly, a drive unit, and a drive motor. The blade assembly includes an aperture blade assembly 2 and a shutter blade assembly 3, which are arranged in layers along the beam emission direction. The drive unit includes an aperture drive unit for driving the aperture blade assembly 2 and a shutter drive unit for driving the shutter blade assembly 3. Both the aperture drive unit and the shutter drive unit are rotatably and coaxially mounted on the base 1 via bearing assemblies. The drive motor is mounted on the base 1 and is meshed with the drive unit via a motor gear to drive the drive unit to rotate. The aperture blade assembly 2 is mounted on the aperture drive unit via a first guide structure, and the shutter blade assembly 3 is mounted on the shutter drive unit via a second guide structure.

[0027] It is understood that this embodiment, by adopting the above technical solution, provides a compact, reliable, and seamlessly integrated dual-layer coupling beam limiter that can integrate general rectangular field imaging and dedicated narrow beam imaging functions. Through its unique dual-layer coupling mechanical structure design, the beam limiter fundamentally solves the problems of radiation leakage, structural complexity, motion jamming, and cumbersome control caused by multi-layer blade stacking in the prior art, and realizes conventional rectangular field imaging as well as narrow beam and low-dose imaging of special parts such as long bones.

[0028] See Figure 1 and Figure 2 In this embodiment, the aperture drive unit includes a first aperture turntable 4 and a second aperture turntable 5, which are rotatably and coaxially mounted on the base 1. The shutter drive unit includes a first shutter turntable 6 and a second shutter turntable 7, which are rotatably and coaxially mounted on the base 1.

[0029] It should be noted that, as Figure 1 and Figure 2 As shown, the base 1 serves as the reference platform and load-bearing structure for the entire device. It possesses high rigidity and precision, ensuring the uniformity of the mounting reference for all moving parts. The aperture drive turntable assembly, i.e., the aperture drive unit, includes the upper aperture turntable (first-layer aperture turntable 4) and the lower aperture turntable (second-layer aperture turntable 5); the shutter drive turntable assembly, i.e., the shutter drive unit, includes the upper shutter turntable (first-layer shutter turntable 6) and the lower shutter turntable (second-layer shutter turntable 7). These are coaxially mounted on the base 1 via a set of precision bearing assemblies. This design ensures that the four turntables share a common center of rotation, eliminating motion interference and precision loss caused by inconsistent references from a mechanical perspective.

[0030] See Figure 1 In this embodiment, the aperture blade assembly 2 includes multiple aperture blades, and the first guide structure includes a guide limiting pin disposed on one side of the aperture blade and a drive pin disposed on the other side of the aperture blade; the first layer aperture turntable 4 is provided with a first guide groove, and the second layer aperture turntable 5 is provided with a second guide groove; the guide limiting pin of the aperture blade is slidably accommodated in the first guide groove of the first layer aperture turntable 4; the drive pin of the aperture blade is slidably accommodated in the second guide groove of the second layer aperture turntable 5.

[0031] In some specific embodiments, the aperture blade assembly 2 includes four aperture blades, each of which is arc-shaped. Each aperture blade has two guide pins on one side and a drive pin on the other side. The aperture blades overlap to form a single-layer opening and closing aperture blade assembly 2. The four aperture blades are stacked vertically, with opposite sides arranged in the same layer. The second-layer aperture turntable 5 has four vertically distributed short guide grooves. The four drive pins of the aperture blade assembly 2 engage in these short guide grooves. The other side of the second-layer aperture turntable 5 is connected to the inner side of the first-layer shutter turntable 6 via a bearing. The first-layer aperture turntable 4 has four vertically distributed long guide grooves and a square hole at a 45° angle to the guide grooves. The eight guide pins of the aperture blade assembly 2 engage in the long guide grooves.

[0032] Understandably, the aperture blade assembly 2 is used to achieve conventional rectangular field-of-view imaging (general mode), such as... Figure 3 As shown, the component consists of four identical arc-shaped aperture blades, stacked vertically and arranged in a single layer on the same plane. Each aperture blade has two pre-embedded guide pins on its upper surface and one pre-embedded drive pin on its lower surface. The four blades are divided into two groups, with opposite blades arranged in the same layer. The upper aperture turntable has four long guide slots, and the lower aperture turntable has four short guide slots. The guide pins of the aperture blades are slidably accommodated in the long guide slots, while the drive pins are accommodated in the short guide slots. All aperture blades move within the same plane, completely eliminating the need for interlayer mounting in traditional multi-layer blade structures. The gaps are the main radiation leakage paths of the multilayer beam limiter. This invention eliminates this risk from the physical structure, significantly improving radiation safety. It eliminates the need for additional complex shielding layers, simplifies the structure, and reduces costs. The guide pin is constrained by the long guide groove of the upper turntable of the aperture, and the drive pin is driven by the short guide groove of the lower turntable of the aperture. The complex two-dimensional planar motion of the blades is decoupled into the simple rotational motion of the two turntables. The cooperation of the long and short guide grooves accurately transforms the rotation of the lower turntable of the aperture into the synchronous and symmetrical radial linear motion of the four blades, thereby forming a high-precision square radiation field opening.

[0033] Preferably, in this embodiment, both the long and short guide grooves are simple straight grooves, and the slope of the straight trajectory remains constant throughout the entire stroke. This fundamentally avoids the uneven force on the blades, motion jamming, or impact caused by sudden changes in the trajectory slope when using complex trajectories such as involutes in the prior art, and greatly improves the smoothness and reliability of the motion.

[0034] See Figure 4In this embodiment, the shutter blade assembly 3 includes multiple shutter blades, the second guide structure includes a shutter guide pin 8 disposed on the shutter blade, the first layer shutter turntable 6 is provided with a concave guide groove, and the shutter guide pin 8 of the shutter blade is slidably accommodated in the concave guide groove; the second layer shutter turntable 7 is provided with a guide rail 9, and the shutter blade is mounted on the guide rail 9 through a guide seat 10.

[0035] Specifically, the shutter blade assembly 3 includes two shutter blades, which are sickle-shaped. Each shutter blade is provided with a shutter guide pin 8. The first-layer shutter turntable 6 is provided with two parallel concave guide grooves. The shutter guide pins 8 of the two shutter blades are respectively housed in the two concave guide grooves. The two shutter blades are arranged in the same layer to form a single-layer opening and closing shutter blade assembly 3. A circular boss is provided on one side of the concave guide groove to limit the axial displacement of the shutter blade assembly 3. The second-layer shutter turntable 7 is provided with two limiting bosses, which are arranged in parallel. Each of the two limiting bosses is equipped with a guide rail 9.

[0036] Understandably, shutter blade assembly 3 is used to achieve narrow field-of-view imaging of special areas such as long bones (dedicated mode), such as... Figure 4 and Figure 5 As shown, the shutter blade assembly 3 includes two sickle-shaped shutter blades arranged opposite each other on the same layer. Each shutter blade engages with a concave guide groove on the upper shutter dial via a guide pin. Simultaneously, the shutter blades are mounted on a guide rail 9 on the lower shutter dial via a guide seat 10. This embodiment preferably uses an Igus standard linear guide rail 9, which features low friction, high precision, and long lifespan. Furthermore, the sickle-shaped blades are specifically designed to form a narrow, elongated irradiation field. When performing full-length imaging of long bones, this design strictly confines X-rays to the target area, significantly reducing radiation dose and scattered radiation in non-target areas, thus protecting the patient and improving image quality. The dual guiding mechanism of the concave guide groove and the linear guide rail 9 ensures that the shutter blades always move along a predetermined straight trajectory during opening and closing, effectively preventing blade swaying and jamming during movement.

[0037] See Figure 1 and Figure 2 In this embodiment, the double-layer coupling limiter further includes a pressure plate 11, which is fixedly connected to the base 1. A boss is provided on the side of the first-layer aperture turntable 4 facing the pressure plate 11, and the pressure plate 11 is sleeved on the outside of the boss to restrict the axial and radial movement of the first-layer aperture turntable 4. Preferably, the first-layer aperture turntable 4 has two bosses, and the two pressure plates 11 respectively cooperate with the bosses to restrict the axial and radial movement of the first-layer aperture turntable 4. At the same time, the pressure plates 11 are also cooperated with the base 1, so that the mounting reference of the upper and lower turntables of the aperture is the base 1, ensuring the uniformity of the opening and closing of the blade group and the symmetry with respect to the intermediate axis.

[0038] It should be noted that, as Figure 2 As shown, the upper aperture turntable has two bosses, and two pressure plates 11 respectively mate with the bosses and are fixed to the base 1 by bolts. This design limits the axial movement and radial runout of the upper aperture turntable, ensuring high-precision coaxiality between its rotation center and the base 1 reference, while avoiding excessive rotational resistance caused by pressing the turntable too hard. The lower shutter turntable is limited to the base 1 by the first bearing 19, and the upper shutter turntable is limited to the base 1 by the second bearing 20 and the lower aperture turntable by the third bearing 21. This multi-layer bearing limiting structure ensures that the two turntables, the aperture and the shutter, maintain extremely high coaxiality and smooth movement when they move independently or in tandem, which is the basis for achieving high-precision and high-reliability composite motion.

[0039] See Figure 1 In this embodiment, the dual-layer coupling limiter further includes a photoelectric switch unit, which is fixedly mounted on the base 1 and used to detect the initial positions of the aperture drive unit and the shutter drive unit. The photoelectric switch unit includes a first photoelectric switch 12 and a second photoelectric switch 13; the first photoelectric switch 12 is used to detect the initial position of the first-layer aperture turntable 4, and the second photoelectric switch 13 is used to detect the initial position of the second-layer aperture turntable 5.

[0040] Furthermore, the dual-layer coupling beam limiter also includes a shielding plate 14, which is disposed on the first-layer aperture turntable 4. The distance between the extreme position of the first-layer aperture turntable 4 under its limiting structure and the light column of the first photoelectric switch 12 is less than or equal to the length of the shielding plate 14; the distance between the extreme position of the second-layer aperture turntable 5 under its limiting structure and the light column of the second photoelectric switch 13 is less than or equal to the length of the shielding plate 14. This ensures that the system can know the current starting position of the first-layer aperture turntable 4 even when the beam limiter is transported under power failure, avoiding secondary collision verification. The second photoelectric switch 13 is arranged on one side of the square opening directly opposite the X-ray detector and opened to its maximum position, and the length of the photoelectric switch shielding plate 14 is greater than or equal to the distance between the extreme position of the turntable and the light column of the photoelectric switch. This ensures that the system can know the current starting position of the second-layer aperture turntable 5 even when the beam limiter is transported under power failure, avoiding secondary collision verification.

[0041] Understandably, in order to achieve precise self-positioning after power-on, such as Figure 1 and Figure 2As shown, the dual-layer coupling limiter of this embodiment is equipped with photoelectric switch units, including a zero-position photoelectric switch on the upper turntable of the aperture (first photoelectric switch 12) and a zero-position photoelectric switch on the lower turntable of the aperture (second photoelectric switch 13), as well as a zero-position photoelectric switch on the upper turntable of the shutter and a zero-position photoelectric switch on the lower turntable of the shutter. All photoelectric switches are fixed on the base 1. The key feature is that a blocking plate 14 is provided on the upper turntable of the aperture. Its length is designed to be greater than or equal to the entire movement stroke of the turntable under its mechanical limit. This ensures that after the device is powered off, no matter where the turntable is stationary in the movement stroke, the blocking plate 14 can always cover the corresponding photoelectric switch light column. This allows the system to quickly and accurately identify the current position of the turntable and return to the mechanical zero position without complex secondary collision verification during power-on initialization. This achieves calibration upon power-on, greatly improving the intelligence level of the device and the user experience, while avoiding the risk of mechanical collision during the initialization process.

[0042] See Figure 2 The dual-layer coupling limiter also includes drive motors, which are fixedly mounted on the base 1. The drive motors include an aperture drive motor and a shutter drive motor. The aperture drive motor drives the aperture drive unit to rotate, and the shutter drive motor drives the shutter drive unit to rotate. The aperture drive motor includes a first-layer aperture turntable drive motor 15 and a second-layer aperture turntable drive motor 16, and the shutter drive motor includes a first-layer shutter turntable drive motor 17 and a second-layer shutter turntable drive motor 18. Both the upper and lower aperture turntables and the upper and lower shutter turntables are driven by their respective stepper motors, all of which are of the same specification and model, ensuring control stability.

[0043] It should be further explained that the drive motor assembly provides power to the entire system, such as... Figure 2As shown, each motor meshes with the teeth on the outer periphery of the corresponding turntable via a motor gear on its output shaft. Specifically, the output shaft of the first-layer aperture turntable drive motor 15 is equipped with a first motor gear 22, and the first-layer aperture turntable drive motor 15 meshes with the first-layer aperture turntable 4 via the first motor gear 22, thereby driving the first-layer aperture turntable 4 to rotate. The output shaft of the second-layer aperture turntable drive motor 16 is equipped with a second motor gear 23, and the second-layer aperture turntable drive motor 16 meshes with the second-layer aperture turntable 5 via the second motor gear 23, thereby driving the second-layer aperture turntable 5 to rotate. The output shaft of the first-layer shutter turntable drive motor 17 is equipped with a third motor gear 24, and the first-layer shutter turntable drive motor... 17 is connected to the first shutter turntable 6 via the third motor gear 24, thereby driving the first shutter turntable 6 to rotate; the output shaft of the second shutter turntable drive motor 18 is provided with a fourth motor gear 25, and the second shutter turntable drive motor 18 is connected to the second shutter turntable 7 via the fourth motor gear 25, thereby driving the second shutter turntable 7 to rotate. The stepper motor has precise angular displacement control capability, and can precisely control the rotation angle of the turntable by controlling the number of pulses, thereby achieving precise positioning of the size and direction of the shooting field. At the same time, in the motor braking state, the stepper motor can provide sufficient holding torque to reliably lock the turntable, providing a guarantee for the realization of a single motion mode (such as opening and closing only or rotation only).

[0044] It should be noted that the operation of the dual-layer coupling beam limiter in this embodiment includes: The drive motor drives the aperture drive unit and shutter drive unit to rotate through motor gear transmission, ultimately converting the rotational motion of the drive unit into the linear motion of the blades or the overall rotation. The entire process can be divided into general mode and special mode, as detailed below: 1. In general mode, that is, when performing regular rectangular field-of-view imaging, such as... Figure 3 and Figure 6 As shown: Figure 3 For a pure opening and closing action (changing the size of the rectangle): The first-layer aperture turntable drive motor 15 is locked, thereby fixing the upper aperture turntable. The second-layer aperture turntable drive motor 16 is started, which drives the lower aperture turntable to rotate through the second motor gear 23. The rotational motion of the lower aperture turntable pushes the drive pins of the four aperture blades through the short guide groove on it. Since the upper aperture turntable is locked, the long guide groove on it constrains the guide limit pins of the aperture blades, forcing the rotational motion of the lower aperture turntable into the synchronous and symmetrical radial linear motion of the four blades. All aperture blades move towards the center or spread out to the edge at the same time in the same plane, thereby realizing the opening and closing of the square field opening.

[0045] Figure 6For pure rotational motion (changing the direction of the rectangle): the second-layer aperture turntable drive motor 16 is locked, thereby fixing the lower aperture turntable. The first-layer aperture turntable drive motor 15 is started, and the upper aperture turntable is driven to rotate through the first motor gear 22. The rotation of the upper aperture turntable drives the guide limit pins of all aperture blades through its long guide groove. Since the lower turntable is fixed, the entire aperture blade assembly 2 rotates synchronously around the central axis of the device as a whole, thereby changing the direction of the shooting field while its opening size remains unchanged.

[0046] 2. In dedicated mode, that is, when narrow-beam imaging of long bones or other areas is required, such as... Figure 4 and Figure 5 As shown: Figure 4 For a pure opening and closing action (changing the width of the narrow slit): the first-layer aperture turntable drive motor 15, the second-layer aperture turntable drive motor 16, and the second-layer shutter turntable drive motor 18 are all locked, thereby fixing the lower shutter turntable. The first-layer shutter turntable drive motor 17 is started, driving the upper shutter turntable to rotate. The rotation of the upper shutter turntable pushes the guide pin of the shutter blade through its concave guide groove. Since the lower shutter turntable is locked, the guide rail 9 on it provides linear constraint on the shutter blade guide seat 10, converting the rotational motion of the upper turntable into precise, opposite linear motion of two sickle-shaped blades, causing them to move closer or further apart, thereby forming a narrow slit with an adjustable width.

[0047] Figure 5 For pure rotational motion (changing the direction of the narrow slit): the first-layer aperture turntable drive motor 15, the second-layer aperture turntable drive motor 16, and the first-layer shutter turntable drive motor 17 are all locked, thereby fixing the upper shutter turntable. The second-layer shutter turntable drive motor 18 is started, driving the lower shutter turntable to rotate. The rotation of the lower shutter turntable drives the entire shutter blade assembly 3 to rotate synchronously around the central axis as a whole through its guide rail 9, thereby changing the direction of the narrow beam irradiation field.

[0048] It should be noted that this embodiment provides a dual-layer coupling beam limiter. By arranging the aperture and shutter blade assemblies in layers along the beam exit direction and integrating their drive units coaxially on the same base 1 via bearing assemblies, and employing a direct drive method via gear meshing of the drive motor, a highly integrated dual-layer coupling beam limiter structure is constructed. This achieves seamless integration of two core functions—general rectangular field imaging and dedicated narrow-beam field imaging—within the same beam limiting device. The dual-layer structure design allows the beam limiter to flexibly adjust the irradiation field shape according to different clinical needs, effectively reducing unnecessary radiation exposure. It satisfies both conventional rectangular imaging and narrow-beam imaging of special areas such as long bones, further improving the ease of use of C-arm and other equipment in complex surgeries.

[0049] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0050] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A dual-layer coupling beam limiter, characterized in that, include: Base (1); The blade assembly includes an aperture blade assembly (2) and a shutter blade assembly (3), wherein the aperture blade assembly (2) and the shutter blade assembly (3) are arranged in layers along the beam exit direction; The driving unit includes an aperture driving unit for driving the aperture blade assembly (2) and a shutter driving unit for driving the shutter blade assembly (3). The aperture driving unit and the shutter driving unit are rotatably coaxially mounted on the base (1) via a bearing assembly. A drive motor is mounted on the base (1). The drive motor is connected to the drive unit via a motor gear and is used to drive the drive unit to rotate. The aperture blade assembly (2) is mounted on the aperture drive unit via a first guide structure, and the shutter blade assembly (3) is mounted on the shutter drive unit via a second guide structure.

2. The dual-layer coupling beam limiter according to claim 1, characterized in that, The aperture drive unit includes a first aperture turntable (4) and a second aperture turntable (5), which are rotatably coaxially mounted on the base (1).

3. The dual-layer coupling limiter according to claim 2, characterized in that, The shutter drive unit includes a first shutter turntable (6) and a second shutter turntable (7), which are rotatably coaxially mounted on the base (1).

4. The dual-layer coupling limiter according to claim 2, characterized in that, The aperture blade assembly (2) includes multiple aperture blades, and the first guide structure includes a guide limiting pin disposed on one side of the aperture blade and a drive pin disposed on the other side of the aperture blade.

5. The dual-layer coupling limiter according to claim 4, characterized in that, The first layer aperture turntable (4) is provided with a first guide groove, and the second layer aperture turntable (5) is provided with a second guide groove; The guide pin of the aperture blade is slidably accommodated in the first guide groove of the first layer aperture turntable (4); The drive pin of the aperture blade is slidably housed in the second guide groove of the second layer aperture turntable (5).

6. The dual-layer coupling beam limiter according to claim 5, characterized in that, The aperture blade assembly (2) includes four aperture blades. The aperture blades are arc-shaped. Each aperture blade has two guide pins on one side and a drive pin on the other side. The aperture blades overlap each other to form a single-layer opening and closing aperture blade assembly (2).

7. The dual-layer coupling beam limiter according to claim 3, characterized in that, The shutter blade assembly (3) includes a plurality of shutter blades, and the second guide structure includes a shutter guide pin (8) disposed on the shutter blades. The first layer shutter turntable (6) is provided with a concave guide groove, and the shutter guide pin (8) of the shutter blade is slidably accommodated in the concave guide groove; The second-layer shutter turntable (7) is provided with a guide rail (9), and the shutter blades are mounted on the guide rail (9) through a guide seat (10).

8. The dual-layer coupling beam limiter according to claim 7, characterized in that, The shutter blade assembly (3) includes two shutter blades, each of which is sickle-shaped. Each shutter blade is provided with a shutter guide pin (8). The first layer shutter turntable (6) is provided with two parallel concave guide grooves. The shutter guide pins (8) of the two shutter blades are respectively housed in the two concave guide grooves. The two shutter blades are arranged in the same layer to form a single-layer opening and closing shutter blade assembly (3).

9. The dual-layer coupling beam limiter according to claim 8, characterized in that, A circular boss is provided on one side of the concave guide groove to limit the axial displacement of the shutter blade assembly (3). The second-layer shutter turntable (7) is provided with two limiting bosses, which are arranged in parallel, and each of the two limiting bosses is equipped with a guide rail (9).

10. The dual-layer coupling beam limiter according to claim 2, characterized in that, The dual-layer coupling limiter includes a pressure plate (11), which is fixedly connected to the base (1). A boss is provided on the side of the first layer aperture turntable (4) facing the pressure plate (11). The pressure plate (11) is sleeved on the outside of the boss to restrict the axial and radial movement of the first layer aperture turntable (4).

11. The dual-layer coupling beam limiter according to claim 2, characterized in that, The dual-layer coupling beam limiter also includes a photoelectric switch unit, which is fixedly mounted on the base (1) and is used to detect the initial positions of the aperture drive unit and the shutter drive unit.

12. The dual-layer coupling beam limiter according to claim 11, characterized in that, The photoelectric switch unit includes a first photoelectric switch (12) and a second photoelectric switch (13); The first photoelectric switch (12) is used to detect the initial position of the first layer aperture turntable (4), and the second photoelectric switch (13) is used to detect the initial position of the second layer aperture turntable (5).

13. The dual-layer coupling beam limiter according to claim 12, characterized in that, The dual-layer coupling limiter includes a blocking plate (14), which is disposed on the first layer aperture turntable (4); The distance between the first layer aperture turntable (4) at its extreme position under its limiting structure and the light column of the first photoelectric switch (12) is less than or equal to the length of the shielding plate (14); The distance between the second-layer aperture turntable (5) at its extreme position under its limiting structure and the light column of the second photoelectric switch (13) is less than or equal to the length of the shielding plate (14).

14. The dual-layer coupling beam limiter according to claim 3, characterized in that, The dual-layer coupling limiter also includes a drive motor, which is fixedly mounted on the base (1); The drive motor includes an aperture drive motor and a shutter drive motor. The aperture drive motor is used to drive the aperture drive unit to rotate, and the shutter drive motor is used to drive the shutter drive unit to rotate. The aperture drive motor includes a first-layer aperture turntable drive motor (15) and a second-layer aperture turntable drive motor (16), and the shutter drive motor includes a first-layer shutter turntable drive motor (17) and a second-layer shutter turntable drive motor (18).

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