Body position fixing device for cone beam CT system

Abstract

The invention relates to the field of medical image scanning and positioning, in particular to a body position fixing device for a cone beam CT system, which comprises a clamping assembly and an adjusting assembly, the clamping assembly comprises two clamping rods, and an elastic clamping block and a linkage structure are arranged at one end, far away from a base, of each clamping rod. In the using process of the fixing device, the adjusting assembly drives the clamping rod to move, and after the elastic clamping blocks on the clamping rod make contact with the surface of the head, the linkage structure can promote the multiple elastic clamping blocks to be attached to the surface of the head. Therefore, through the linkage structure, the fixing device can be flexibly matched with the heads of different sizes, it is ensured that during cone beam CT scanning, no matter how the size of the head of a subject is, the elastic clamping block can be tightly attached to the surface of the head, stable fixing of the heads of different sizes is achieved, and reliable guarantee is provided for accurate scanning.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical image scanning positioning, in particular to a body position fixing device for cone beam CT system. BACKGROUND

[0002] The body position fixing device for cone beam CT system is a key auxiliary equipment to ensure imaging accuracy. Its core purpose is to stabilize the body position of the subject, avoid image artifacts caused by body movement during scanning, and ensure that clear and unbiased tomographic images are obtained, providing a reliable basis for disease diagnosis and treatment planning.

[0003] However, most of the existing head fixing devices use fixed gears or single adjustment dimension design, which makes the shape and spacing of the fixing device unable to be dynamically adjusted according to the shape of the skull, and it is difficult to cover the large size span from children to adults. When the skull is smaller than the adaptive range of the fixing device, the clamping force cannot effectively act on the stress point; when the skull is larger than the adaptive range, excessive compression can cause discomfort or even injury. SUMMARY

[0004] Therefore, it is necessary to provide a body position fixing device for cone beam CT system to solve the problem that the existing body position fixing device for cone beam CT system cannot effectively clamp the skull with different sizes.

[0005] The above-mentioned purpose is achieved by the following technical solutions: A body position fixing device for cone beam CT system, comprising: a main body.

[0006] a base fixedly connected to the main body.

[0007] a clamping assembly comprising two clamping rods, both of which are slidingly connected to the base, and both of which are provided with elastic clamping blocks and linkage structures at one end away from the base, a plurality of elastic clamping blocks are movably connected to the clamping rods, and the plurality of elastic clamping blocks are used to contact the surface of the head, and the plurality of elastic clamping blocks on both clamping rods can be distributed circumferentially around the skull; the linkage structure is used to make the plurality of elastic clamping blocks adhere to the surface of the head.

[0008] an adjustment assembly for driving both clamping rods to move relative to the base.

[0009] Further, the linkage structure on one of the clamping rods comprises a first rotating block, two second rotating blocks and four third rotating blocks, the clamping rod is provided with a first arc-shaped slot, the outer wall of the first rotating block is embedded in the first arc-shaped slot, and the first rotating block can rotate relative to the clamping rod; the two second rotating blocks are rotationally connected to the first rotating block; and every two third rotating blocks are rotationally connected to one second rotating block, and the elastic clamping block is fixedly arranged on the outer wall of the third rotating block away from the second rotating block.

[0010] Further, the linkage structure on one of the clamping rods further comprises two second sliding blocks and two fixed blocks, the two second sliding blocks are slidingly connected to one second rotating block respectively, and each fixed block is fixedly connected to one second rotating block at an end close to the other second rotating block; the second sliding block and the fixed block are both provided with a third arc-shaped slot, and the third rotating block is embedded in the third arc-shaped slot; and the third rotating block can rotate relative to the second sliding block or the fixed block.

[0011] Further, the linkage structure on one of the clamping rods further comprises two first sliding blocks, the two first sliding blocks are slidingly connected to the first rotating block, the first sliding block is provided with a second arc-shaped slot, the second rotating block is embedded in the second arc-shaped slot, the second rotating block can rotate relative to the first sliding block, and the second rotating block can drive the first sliding block to slide relative to the first rotating block when rotating.

[0012] The first sliding block is fixedly provided with a third rack, the third rack is embedded in the second rotating block, the inner wall of the second rotating block is fixedly provided with a first gear and a second gear, the lower wall of the second sliding block is fixedly provided with a fourth rack, the first gear is meshed with the third rack and the second gear, and the second gear is further meshed with the fourth rack.

[0013] The third rack, the first gear, the second gear and the fourth rack are used for converting the sliding of the first sliding block into the sliding of the second sliding block.

[0014] Further, the first rotating block is fixedly provided with a first rack at an end away from the clamping rod, the outer wall of the second rotating block is fixedly provided with a second rack, and the first rack is meshed with the second rack to convert the rotation of the second rotating block into the sliding of the first sliding block.

[0015] Further, the adjusting assembly comprises a first driving wheel and a first driving rod, the first driving wheel is coaxially fixedly connected to the first driving rod, the first driving rod is rotationally connected to the base along the length direction of the base, and the first driving rod is connected to the two clamping rods.

[0016] Further, the adjusting assembly further comprises a self-locking structure, when the clamping force of the two clamping rods on the head reaches a threshold value, the self-locking structure limits the two clamping rods from continuing to move.

[0017] Further, the self-locking structure comprises two sliding housings, a plurality of limiting nails, a limiting tooth plate and a first elastic member, the two sliding housings are slidingly connected to the base, the two sliding housings are threadedly connected to the first driving rod, and rotating the first driving rod can drive the two sliding housings to move towards opposite directions relative to the base, the plurality of limiting nails are slidingly connected to each sliding housing, the limiting nails can be clamped into the limiting tooth plate to limit the movement of the sliding housing relative to the base, the limiting tooth plate is fixedly connected to the inner wall of the base and extends along the length direction of the base, one end of the clamping rod close to the base is fixedly provided with a trapezoidal block, the trapezoidal block is slidingly connected to the first driving rod and can move relative to the sliding housing, and the side wall of the trapezoidal block can abut against the limiting nail, one end of the first elastic member is fixedly arranged on the inner wall of the sliding housing close to the base, and the other end of the first elastic member is fixedly arranged on the side wall of the trapezoidal block close to the base, and the elastic force of the first elastic member always makes the trapezoidal block and the sliding housing move away from each other or have a tendency to move away from each other.

[0018] When the clamping force of the two clamping rods on the head reaches a threshold value, the trapezoidal block drives the limiting nail to move towards the limiting tooth plate and clamps into the limiting tooth plate, thereby limiting the sliding housing from continuing to move relative to the base.

[0019] Further, a second elastic member is fixedly arranged between the limiting nail and the sliding housing, and the elastic force of the second elastic member always makes the limiting nail be in an initial position.

[0020] Further, the adjusting assembly further comprises a second driving wheel and a second driving rod, the second driving wheel is coaxially fixedly connected to the second driving rod, the second driving rod is rotationally connected to the base, the second driving rod extends along the width direction of the base, the limiting tooth plate is slidingly connected to the base, and the second driving rod is threadedly rotationally connected to the limiting tooth plate, and rotating the second driving rod can adjust the distance between the limiting tooth plate and the limiting nail.

[0021] The beneficial effects of this invention are: This invention provides a body positioning device for a cone-beam computed tomography (CBCT) system, comprising a clamping assembly and an adjusting assembly. The clamping assembly includes two clamping rods, with an elastic clamping block and a linkage structure at the end of each rod furthest from the base. In use, the adjusting assembly drives the clamping rods to move, bringing the elastic clamping block into contact with the subject's head surface. Simultaneously, as the clamping rods move further, the linkage structure causes multiple elastic clamping blocks to adapt to the head surface shape relative to the clamping rods, ensuring that all elastic clamping blocks conform to the head surface. Therefore, for smaller heads, the elastic clamping blocks adjust their position and angle under the action of the linkage structure, achieving stable contact within a smaller clamping range. For larger heads, the linkage structure causes multiple elastic clamping blocks to adapt, expanding the contact area and maintaining uniform force, avoiding instability caused by differences in head size, ensuring the head does not wobble during scanning, and thus guaranteeing image quality. Furthermore, this fixation device eliminates the need for specialized fixation components for different head sizes, greatly improving the versatility and ease of use of the device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a body positioning device for a cone-beam CT system provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the base, mandibular support plate, clamping assembly, and adjustment assembly in the positioning device for a mid-cone-beam CT system; Figure 3 for Figure 2 Side view of the base, mandibular support, clamping assembly, and adjustment assembly in the positioning device for a mid-cone-beam CT system; Figure 4 for Figure 3 A schematic diagram of the cross-section along the AA direction; Figure 5 for Figure 3 Schematic diagram of the cross section in the middle BB direction; Figure 6 for Figure 3 A schematic diagram of the cross-section in the CC direction; Figure 7 for Figure 4 A magnified view of a section at point D; Figure 8 for Figure 5 A magnified view of a section at point E in the middle; Figure 9 This is a schematic diagram of the linkage structure in the body positioning device for a cone-beam CT system. Figure 10 forFigure 9 Schematic view of the front cross section of the linkage structure in the body fixation device of the medium cone beam CT system.

[0023] Wherein: 110, main body; 111, fixing ring; 120, scanner; 210, base; 220, mandibular support plate; 221, bite block; 300, clamping assembly; 310, clamping rod; 320, elastic clamping block; 330, first rotating block; 331, first rack; 332, first gear; 333, second gear; 334, third gear; 340, second rotating block; 341, second rack; 350, third rotating block; 360, first sliding block; 361, third rack; 370, second sliding block; 371, fourth rack; 380, fixed block; 400, adjusting assembly; 410, first driving wheel; 420, first driving rod; 430, sliding shell; 440, trapezoidal block; 441, first elastic member; 450, limiting nail; 451, second elastic member; 460, limiting toothed plate; 470, second driving wheel; 480, second driving rod. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the present application clearer, the following further describes the present application with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0025] The serial numbers of components in the present application, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequence or technical meaning. The "connection" and "coupling" in the present application include direct and indirect connection (coupling) unless otherwise specified. In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or just means that the first feature is horizontally higher than the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or just means that the first feature is horizontally lower than the second feature.

[0027] The following refers to Figures 1 to 10 The body position fixing device for cone beam CT system provided by the embodiment of the present application is described.

[0028] Specifically, the body position fixing device for cone beam CT system includes a main body 110, a base 210, a mandibular support plate 220, a clamping assembly 300 and an adjusting assembly 400.

[0029] The main body 110 is in a frame structure, used for bearing other components and providing a stable support basis for the subject. The lower part of the main body 110 is sleeved with a fixing ring 111, which is in an annular structure. The inner wall surface of the fixing ring 111 is closely combined with the main body 110, and the main body 110 can be fixed on a fixed surface through bolts or other connecting members to avoid shaking or displacement of the main body 110 during work, thereby providing a stable installation basis for other components.

[0030] The top of the main body 110 can be mounted with a scanner 120, which is used for emitting and receiving cone beam rays to finally complete tomographic scanning and generate clear images through all-around ray scanning of the head region.

[0031] The base 210 is fixed on the main body 110, serving as a mounting carrier for the mandibular support plate 220, the clamping assembly 300 and the adjusting assembly 400, and providing stable support.

[0032] The mandibular support plate 220 is horizontally fixed on the base 210, and the position of the mandibular support plate 220 corresponds to the scanner 120, which can accurately support the mandibular part of the subject. The mandibular support plate 220 provides stable support for the head from below, ensuring that the head is at an appropriate height and position during scanning. The mandibular support plate 220 is fixedly provided with a bite 221, which is an arc-shaped bite pad adapted to the teeth. The bite 221 is used to firmly fix the upper and lower jaw positions after the subject bites, further limiting the movement of the head in the front and rear directions, thereby enhancing the stability of the overall fixation.

[0033] The clamping assembly 300 includes two clamping rods 310, which are both slidingly connected to the base 210 and can move along the length direction of the base 210.

[0034] Each clamping rod 310 is provided with a plurality of elastic clamping blocks 320 and linkage structures at the end away from the base 210. The elastic clamping blocks 320 are movably connected to the clamping rod 310, and can flexibly adjust the contact angle according to the curvature of the surface of the head of the subject. The plurality of elastic clamping blocks 320 on the two clamping rods 310 can be distributed circumferentially around the head and wrap the head of the subject from both sides. The linkage structures enable the plurality of elastic clamping blocks 320 to move relative to the clamping rod 310 synchronously according to the shape of the surface of the head of the subject through mechanical transmission, so as to ensure that the plurality of elastic clamping blocks 320 can be closely attached to the surface of the head.

[0035] The adjusting assembly 400 can drive the two clamping rods 310 to move closer to or away from each other relative to the base 210, so as to adjust the clamping distance of the two clamping rods 310 and adapt to subjects with different head shapes.

[0036] In use, first, the main body 110 is fixed at a predetermined position by the fixing ring 111, so as to ensure that the entire fixing device is stably installed. Then, the subject places the lower jaw on the lower jaw supporting plate 220 and bites the bite plate 221, so as to fix the upper and lower jaws. Next, the adjusting assembly 400 is operated to drive the two clamping rods 310 to slide along the length direction of the base 210 and move closer to each other, until the elastic clamping blocks 320 at the two ends of the clamping rods 310 contact the two sides of the head of the subject. At this time, the linkage structures drive the elastic clamping blocks 320 to adjust according to the shape of the surface of the head, so as to achieve close attachment circumferentially around the head. After confirming that the head is stably fixed and the subject has no obvious discomfort, the scanner 120 is started to scan the head region.

[0037] Further, in the embodiment, four elastic clamping blocks 320 are provided on each clamping rod 310. The linkage structure on one clamping rod 310 includes a first rotating block 330, two second rotating blocks 340, four third rotating blocks 350, two first sliding blocks 360, two second sliding blocks 370, and two fixed blocks 380.

[0038] The first rotating block 330, the second rotating block 340, and the third rotating block 350 are provided in the shape of semicircles with different diameters, and the diameters decrease in turn.

[0039] The clamping rod 310 is provided with a first arc-shaped groove along the shape of the outer wall of the first rotating block 330. The outer wall of the first rotating block 330 is embedded in the first arc-shaped groove. The first rotating block 330 and the clamping rod 310 form a rotating connection, so that the first rotating block 330 can rotate relative to the clamping rod 310.

[0040] The outer wall surface of the two second rotating blocks 340 is fixedly provided with a second rack 341, the end wall of the first rotating block 330 away from the clamping rod 310 is fixedly provided with a first rack 331, and the second rack 341 and the first rack 331 are engaged with each other, so that the two second rotating blocks 340 can rotate relative to the first rotating block 330.

[0041] The two first sliding blocks 360 are slidingly connected to the first rotating block 330 and can slide relative to the first rotating block 330; the inner wall of the first sliding block 360 is provided with a second arc-shaped groove, and one end of the second rotating block 340 is embedded in the second arc-shaped groove, so that the second rotating block 340 can rotate relative to the first sliding block 360. At the same time, the second rotating block 340 can drive the first sliding block 360 to slide relative to the first rotating block 330 when rotating relative to the first rotating block 330.

[0042] The two second sliding blocks 370 are slidingly connected to one second rotating block 340 respectively, and the two fixed blocks 380 are fixedly connected to one second rotating block 340 respectively at one end close to the other second rotating block 340 and are arranged opposite to the second sliding block 370; the second sliding block 370 and the fixed block 380 are both provided with a third arc-shaped groove, and the four third rotating blocks 350 are embedded in one third arc-shaped groove respectively, every two third rotating blocks 350 correspond to one second rotating block 340, and the third rotating block 350 can rotate relative to the second sliding block 370 or the fixed block 380.

[0043] The elastic clamping block 320 is fixedly arranged on the outer wall of the third rotating block 350 away from the second rotating block 340 and directly contacts the surface of the head.

[0044] The first sliding block 360 is also fixedly provided with a third rack 361, the third rack 361 is embedded in the second rotating block 340, the second rotating block 340 is fixedly provided with a first gear 332 and a second gear 333 inside, and the lower wall surface of the second sliding block 370 is fixedly provided with a fourth rack 371. The first gear 332 is engaged with the third rack 361 and the second gear 333 at the same time, and the fourth rack 371 is engaged with the second gear 333.

[0045] When the second rotating block 340 drives the first sliding block 360 to slide relative to the first rotating block 330, the third rack 361 drives the first gear 332 to rotate, and the first gear 332 converts the sliding of the first sliding block 360 into the sliding of the second sliding block 370 through the cooperation of the second gear 333 and the fourth rack 371.

[0046] In use, when the adjusting assembly 400 drives the two clamping rods 310 to move towards the head, the elastic clamping blocks 320 first contact the surface of the head and are subjected to pressure, which causes the third rotating blocks 350 to rotate in the third arc-shaped grooves of the second sliding blocks 370 and the fixed blocks 380, thereby causing the second rotating blocks 340 to rotate relative to the first rotating blocks 330 in the second arc-shaped grooves of the first sliding blocks 360.

[0047] Due to the engagement of the second rack 341 of the second rotating block 340 with the first rack 331 of the first rotating block 330, the rotation of the second rotating block 340 drives the first sliding block 360 to slide along the first rotating block 330; at the same time, the third rack 361 of the first sliding block 360 drives the first gear 332 in the second rotating block 340 to rotate, which in turn drives the second gear 333 to rotate, and the second gear 333 drives the second sliding block 370 to slide along the second rotating block 340 through the engagement with the fourth rack 371.

[0048] Finally, the eight third rotating blocks 350 on the two clamping rods 310 drive the elastic clamping blocks 320 to adjust the angles and positions along the circumference of the head, respectively, to achieve close fitting with different head contours.

[0049] Therefore, through the multi-stage transmission of the linkage structure, when the head size changes, the coordinated movement of the first rotating block 330, the second rotating block 340, the third rotating block 350, the first sliding block 360, the second sliding block 370, and the fixed block 380 can automatically optimize the spacing of the contact points, ensure the reasonable density distribution of the elastic clamping blocks 320, and enable the elastic clamping blocks 320 to adaptively adjust the positions according to the head size, thereby forming uniform clamping force from multiple angles around the head circumference to achieve stable positioning of the head.

[0050] In other embodiments, a third gear 334 is coaxially fixed on the second gear 333, the second gear 333 is engaged with the first gear 332, and the fourth rack 371 is no longer directly engaged with the second gear 333 but is engaged with the third gear 334. When the second gear 333 rotates, the third gear 334 synchronously rotates, thereby driving the second sliding block 370 to slide along the second rotating block 340 through the engagement with the fourth rack 371. Therefore, the movement distance of the second sliding block 370 can be controlled by setting the transmission ratio of the second gear 333 and the third gear 334.

[0051] When the first gear 332 rotates by a certain angle, if the radius of the third gear 334 is greater than that of the second gear 333, after the second gear 333 and the third gear 334 synchronously rotate by a certain angle, the third gear 334 can drive the fourth rack 371 and the second sliding block 370 to move by a greater amount.

[0052] In use, when the head of the examinee contacts the elastic clamping block 320 and pushes the third rotating block 350 to rotate, power is transmitted to the second rotating block 340 and the first sliding block 360 in turn, the third rack 361 of the first sliding block 360 drives the first gear 332 to rotate, the first gear 332 drives the second gear 333 and the coaxial third gear 334 to rotate, and the third gear 334 drives the second sliding block 370 to slide through the meshing with the fourth rack 371. Since the transmission ratio of the second gear 333 and the third gear 334 has been pre-set, the movement amount of the second sliding block 370 will form a stable proportion with the movement amount of the first sliding block 360, thereby enabling the plurality of third rotating blocks 350 connected to the second sliding block 370 and the fixed block 380 to move uniformly along the circumference of the head.

[0053] Thus, by setting the transmission ratio of the second gear 333 and the third gear 334 to provide a controllable proportional relationship for the movement of the second sliding block 370, the plurality of third rotating blocks 350 can uniformly slide along the circumference of the head, driving the elastic clamping block 320 to form balanced contact with the surface of the head, preventing the movement distance of the third rotating blocks 350 at different positions from being too different, causing the head to be clamped too tightly or loosely in some parts, ensuring that the force on the head in all directions is uniform, and further enhancing the stability of the fixation.

[0054] In one embodiment, the adjusting assembly 400 includes a first driving wheel 410 and a first driving rod 420. The surface of the first driving wheel 410 is usually provided with anti-slip patterns to facilitate the operator to hold and rotate. The first driving wheel 410 is coaxially fixedly connected to one end of the first driving rod 420, the first driving rod 420 extends along the length direction of the base 210, and the first driving rod 420 can rotate synchronously with the first driving wheel 410. The side wall of the first driving rod 420 is connected to the two clamping rods 310 through threads, and the threads connected to the first driving rod 420 of the two clamping rods 310 are opposite in direction.

[0055] In use, when it is necessary to adjust the distance between the clamping rods 310 according to the size of the head of the examinee, the operator rotates the first driving wheel 410, and the first driving wheel 410 drives the first driving rod 420 to rotate synchronously. At this time, the first driving rod 420 converts the rotary motion into linear motion of the two clamping rods 310 through threads, and the movement directions of the two clamping rods 310 are opposite. When one clamping rod 310 moves towards the head, the other clamping rod 310 also moves towards the head synchronously, or both clamping rods 310 move away from the head at the same time, thereby achieving the increase or decrease of the clamping distance.

[0056] Thus, by setting the first driving wheel 410 and the first driving rod 420, the rotation of the first driving rod 420 is converted into the synchronous reverse movement of the two clamping rods 310, ensuring that the moving distance of the two clamping rods 310 is equal during the adjustment process, thereby ensuring that the clamping center is always aligned with the scanning center.

[0057] Further, in order to prevent the operator from causing the head of the examinee to be uncomfortable or even injured due to improper force, or the head to be unable to be stably fixed due to insufficient clamping force, the adjustment assembly 400 further comprises a self-locking structure. When the clamping force of the two clamping rods 310 on the head reaches a threshold value, the self-locking structure limits the two clamping rods 310 from continuing to move.

[0058] Specifically, the self-locking structure comprises a sliding shell 430, a trapezoidal block 440, a limiting nail 450, and a limiting tooth plate 460.

[0059] The sliding shell 430 is slidably connected to the base 210 and can reciprocate along the length direction of the base 210; the first driving rod 420 is threadedly connected to the two sliding shells 430, and when the first driving rod 420 is rotated, the two sliding shells 430 move in opposite directions relative to the base 210.

[0060] The trapezoidal block 440 is fixedly arranged at one end of the clamping rod 310 close to the base 210, and the clamping rod 310 is slidably connected to the first driving rod 420 through the trapezoidal block 440 and can slide relative to the inside of the sliding shell 430. The side wall of the trapezoidal block 440 is an inclined surface and can contact the limiting nail 450 and generate a pushing force.

[0061] The limiting nail 450 is slidably arranged on the side wall of the sliding shell 430 and can extend out of the sliding shell 430. One end of the limiting nail 450 can abut against the inclined side wall of the trapezoidal block 440, and the other end of the limiting nail 450 can extend out of the sliding shell 430 and cooperate with the limiting tooth plate 460.

[0062] The limiting tooth plate 460 is fixedly connected to the inner wall of the base 210 and extends along the length direction of the base 210. The surface of the limiting tooth plate 460 is uniformly provided with a plurality of tooth grooves, and the tooth grooves can be engaged with the one end of the limiting nail 450 extending out, thereby limiting the movement of the sliding shell 430 relative to the base 210.

[0063] A first elastic member 441 is fixedly arranged between the sliding shell 430 and the trapezoidal block 440. One end of the first elastic member 441 is fixedly arranged on the inner wall of the one end of the sliding shell 430 close to the base 210, and the other end of the first elastic member 441 is fixedly arranged on the side wall of the trapezoidal block 440 close to the base 210. The elastic force of the first elastic member 441 always urges the trapezoidal block 440 and the sliding shell 430 to move away from each other.

[0064] The second elastic member 451 is fixedly arranged between the limiting pin 450 and the sliding shell 430, and the elastic force of the second elastic member 451 always keeps the limiting pin 450 in the initial position, i.e., the position not engaged with the limiting tooth plate 460.

[0065] During use, when the operator rotates the first driving wheel 410, the first driving rod 420 drives the two sliding shells 430 to move in opposite directions. The sliding shell 430 pushes the trapezoidal block 440 through the first elastic member 441, thereby driving the clamping rod 310 to move towards the head.

[0066] As the clamping rod 310 gradually approaches the head, the clamping force of the clamping rod 310 on the head increases. The reaction force of the head on the clamping rod 310 pushes the trapezoidal block 440 to move relative to the sliding shell 430 towards the base 210 against the elastic force of the first elastic member 441. The inclined side wall of the trapezoidal block 440 is pressed against the limiting pin 450, so that the limiting pin 450 moves towards the limiting tooth plate 460 against the elastic force of the second elastic member 451. When the clamping force reaches a preset threshold, the limiting pin 450 is completely engaged in the tooth groove of the limiting tooth plate 460, at which time the sliding shell 430 is restricted from moving further relative to the base 210, thereby limiting the clamping rod 310 from further approaching the head through the trapezoidal block 440, and self-locking is achieved.

[0067] By setting the elastic force of the first elastic member 441 as the clamping force threshold, when the clamping force does not reach the threshold, the elastic force of the first elastic member 441 does not cause the trapezoidal block 440 to press against the limiting pin 450, and the limiting pin 450 remains in the initial position under the action of the second elastic member 451, so that the sliding shell 430 can normally drive the clamping rod 310 to move; when the clamping force reaches the threshold, the trapezoidal block 440 moves against the elastic force of the first elastic member 441 and pushes the limiting pin 450 to engage in the limiting tooth plate 460, thereby limiting the clamping rod 310 from further moving through mechanical locking.

[0068] After detection is completed, the first driving wheel 410 is rotated in the opposite direction, the first driving rod 420 is rotated in the opposite direction, and the two sliding shells 430 move along the base 210 in opposite directions. At this time, the reaction force of the head on the clamping rod 310 disappears, the trapezoidal block 440 moves away from the base 210 relative to the sliding shell 430 under the action of the elastic force of the first elastic member 441, and the pressing force of the inclined side wall of the trapezoidal block 440 on the limiting pin 450 gradually decreases until it disappears. The limiting pin 450 is pulled out of the tooth groove of the limiting tooth plate 460 under the action of the elastic force of the second elastic member 451, the restriction on the sliding shell 430 is removed, and the limiting pin 450 returns to the initial position. As the sliding shell 430 continues to move in the opposite direction, the trapezoidal block 440 drives the clamping rod 310 to move away from the head synchronously, the elastic clamping block 320 is separated from the surface of the head, and the entire clamping assembly 300 returns to the initial state.

[0069] Therefore, the clamping force of the clamping rod 310 on the head can be stabilized in a safe and effective range, avoiding discomfort or injury of the subject caused by excessive clamping force, while ensuring sufficient clamping force to prevent the head of the subject from shaking, and reducing the dependence on the experience of the operator, improving the safety and convenience of operation.

[0070] In one of the embodiments, the adjusting assembly 400 further comprises a second driving wheel 470 and a second driving rod 480. The surface of the second driving wheel 470 is generally provided with anti-slip patterns for the operator to hold, and the second driving rod 480 is fixedly connected coaxially with the second driving wheel 470. The outer surface of the second driving rod 480 is provided with threads, and both ends thereof are rotationally connected to the base 210 and extend along the width direction of the base 210.

[0071] In the above embodiment, the limiting tooth plate 460 is modified to be slidingly connected to the base 210, so that the limiting tooth plate 460 can move along the width direction of the base 210; and the second driving rod 480 is rotationally connected to the limiting tooth plate 460 through threads. When the second driving rod 480 rotates, the second driving rod 480 rotates around its own axis, and in turn drives the limiting tooth plate 460 to slide along the width direction of the base 210 through the threads, thereby changing the distance between the limiting tooth plate 460 and the limiting peg 450.

[0072] In use, when it is necessary to adjust the self-locking trigger threshold of the clamping assembly 300 according to the age of the subject, the sensitivity of the head, etc., that is, when the clamping force reaches how much the self-locking structure is triggered, the operator rotates the second driving wheel 470, which drives the second driving rod 480 to rotate synchronously, and moves the limiting tooth plate 460 along the width direction of the base 210 through thread transmission: if it moves towards the limiting peg 450, the distance between the limiting tooth plate 460 and the limiting peg 450 decreases, and the limiting peg 450 only needs a smaller pushing force to be clamped into the tooth groove, and the corresponding clamping force threshold of the self-locking structure is lowered; if it moves away from the limiting peg 450, the distance increases, and the limiting peg 450 needs a larger pushing force to be clamped in, and the corresponding clamping force threshold is raised. After the adjustment is completed, the position of the limiting tooth plate 460 is fixed, and the self-locking structure will trigger the locking action at the new threshold.

[0073] Therefore, by changing the initial distance between the limiting tooth plate 460 and the limiting peg 450 through the second driving wheel 470 and the second driving rod 480, and then adjusting the pushing force required for the limiting peg 450 to be clamped into the tooth groove, the clamping force threshold can be accurately adjusted according to the specific circumstances of different subjects, ensuring the safety of children, sensitive groups, etc., and ensuring the stability in scenarios such as adults who need stronger fixation, greatly improving the universality and applicability of the fixing device.

[0074] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described above. However, any combination of the technical features is deemed to be within the scope of the present disclosure as long as such a combination does not result in an inconsistency.

[0075] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A body fixation device for a cone beam CT system, characterized by, Include: A main body; A base fixedly connected to the main body; A clamping assembly including two clamping rods, two clamping rods slidingly connected to the base, two clamping rods distal to the base end are provided with elastic clamping block and linkage structure, a plurality of elastic clamping blocks movably connected to the clamping rod, a plurality of elastic clamping blocks for contacting the head surface, a plurality of elastic clamping blocks on two clamping rods can be distributed along the circumference of the head; the linkage structure is used for enabling a plurality of elastic clamping blocks to be attached to the head surface; Adjusting assembly for driving two clamping rods relative to the base.

2. The body fixation device for a cone beam CT system according to claim 1, wherein The linkage structure on one of the clamping rods includes a first rotating block, two second rotating blocks and four third rotating blocks, the clamping rod is provided with a first arc-shaped groove, the outer wall of the first rotating block is embedded in the first arc-shaped groove, and the first rotating block can rotate relative to the clamping rod; two second rotating blocks are rotatably connected to the first rotating block; every two third rotating blocks are rotatably connected to a second rotating block, and the elastic clamping block is fixedly arranged on the outer wall of the third rotating block away from the second rotating block.

3. The body fixation device for a cone beam CT system according to claim 2, wherein The linkage structure on one of the clamping rods further includes two second sliding blocks and two fixed blocks, two second sliding blocks are slidingly connected to one of the second rotating blocks, and each fixed block is fixedly connected to one end of the second rotating block close to the other second rotating block. The second sliding block and the fixed block are provided with a third arc-shaped groove, the third rotating block is embedded in the third arc-shaped groove, and the third rotating block can rotate relative to the second sliding block or the fixed block.

4. The body fixation device for a cone beam CT system according to claim 3, wherein The linkage structure on one of the clamping rods further includes two first sliding blocks, two first sliding blocks slidingly connected to the first rotating block, the first sliding block is provided with a second arc-shaped groove, the second rotating block is embedded in the second arc-shaped groove, and the second rotating block can rotate relative to the first sliding block. The second rotating block can drive the first sliding block to slide relative to the first rotating block when rotating; The first sliding block is fixedly provided with a third rack, the third rack is embedded in the second rotating block, the inner wall of the second rotating block is fixedly provided with a first gear and a second gear, the lower wall of the second sliding block is fixedly provided with a fourth rack, the first gear is meshed with the third rack and the second gear, and the second gear is also meshed with the fourth rack; The third rack, the first gear, the second gear and the fourth rack are used to convert the sliding of the first sliding block into the sliding of the second sliding block.

5. The body fixation device for a cone beam CT system according to claim 4, wherein The first rotating block is fixedly provided with a first rack at the end away from the clamping rod, the outer wall of the second rotating block is fixedly provided with a second rack, and the first rack is meshed with the second rack to convert the rotation of the second rotating block into the sliding of the first sliding block.

6. The body fixation device for a cone beam CT system according to claim 1, wherein The adjusting assembly comprises a first driving wheel and a first driving rod, the first driving wheel is coaxially fixedly connected to the first driving rod, the first driving rod is rotationally connected to the base along the length direction of the base, and the first driving rod is connected to the two clamping rods.

7. The body fixation device for a cone beam CT system according to claim 6, wherein When the clamping force of the two clamping rods on the head reaches a threshold value, the self-locking structure limits the two clamping rods from continuing to move.

8. The body fixation device for a cone beam CT system according to claim 7, characterized by The self-locking structure comprises two sliding housings, a plurality of limiting nails, a limiting tooth plate and a first elastic member; the two sliding housings are slidingly connected to the base, and the two sliding housings are threadedly connected to the first driving rod, and rotating the first driving rod can drive the two sliding housings to move towards opposite directions relative to the base; A plurality of limiting nails are slidingly connected to each sliding housing, the limiting nails can be clamped into the limiting tooth plate to limit the movement of the sliding housing relative to the base; the limiting tooth plate is fixedly connected to the inner wall of the base and extends along the length direction of the base; one end of the clamping rod close to the base is fixedly provided with a trapezoidal block, the trapezoidal block is slidingly connected to the first driving rod and can move relative to the sliding housing, and the side wall of the trapezoidal block can abut against the limiting nail; one end of the first elastic member is fixedly arranged on the inner wall of the end of the sliding housing close to the base, and the other end of the first elastic member is fixedly arranged on the side wall of the trapezoidal block close to the base, and the elastic force of the first elastic member always makes the trapezoidal block and the sliding housing move away from each other or have a tendency to move away from each other; When the clamping force of the two clamping rods on the head reaches a threshold value, the trapezoidal block drives the limiting nails to move towards the limiting tooth plate and clamps into the limiting tooth plate, thereby limiting the sliding housing from continuing to move relative to the base.

9. The body fixation device for a cone beam CT system according to claim 8, wherein A second elastic member is fixedly arranged between the limiting nail and the sliding housing, and the elastic force of the second elastic member always makes the limiting nail be in an initial position.

10. The body fixation device for a cone beam CT system according to claim 8, wherein The adjusting assembly further comprises a second driving wheel and a second driving rod, the second driving wheel is coaxially fixedly connected to the second driving rod, the second driving rod is rotationally connected to the base, the second driving rod extends along the width direction of the base, the limiting tooth plate is slidingly connected to the base, and the second driving rod is threadedly rotationally connected to the limiting tooth plate, and rotating the second driving rod can adjust the distance between the limiting tooth plate and the limiting nail.

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