Mobile CBCT rotation motion compensation method and system

Abstract

The invention discloses a mobile CBCT (cone beam computed tomography) rotation motion compensation method and system, and the method comprises the steps: collecting rotation shaft motion data through a motion monitoring module, analyzing and judging the motion stability, adjusting the rotation speed of a driving mechanism through a PID (proportion integration differentiation) control algorithm when the motion is not stable, predicting a motion track through a Kalman filtering model to generate an exposure triggering delay signal, and outputting the exposure triggering delay signal. The X-ray exposure intensity is dynamically adjusted, and dynamic synchronous control is realized through closed-loop feedback; the system comprises a rack, a rotating shaft, a driving mechanism, a motion monitoring module, a motion compensation module and an X-ray adjusting unit, and a limiting mechanism and a buffering mechanism are additionally arranged to improve stability. According to the scheme, through real-time monitoring and dynamic compensation of the motion data, the sub-degree synchronization precision of the rotation motion and the exposure process is achieved, the collision noise is reduced to 55 dB or below, the vibration acceleration is reduced to 3 g or below, the image collection quality and the equipment operation stability are remarkably improved, and the method is suitable for mobile scenes such as emergency treatment and operation.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a method and system for compensating the rotational movement of a mobile CBCT (mobile cone beam computed tomography device), which is particularly suitable for solving the problem of asynchronous X-ray exposure caused by unstable movement during the rotational scanning of a mobile CBCT device, so as to improve the effectiveness of image acquisition and the stability of the device. Background Art

[0002] The mobile CBCT performs circular digital projection around the irradiated object through an X-ray generator, and recombines the multiple projection data to obtain a three-dimensional image. In this process, the movement stability of the rotating mechanism and the synchronization of X-ray exposure are the key factors affecting the imaging quality.

[0003] In the prior art, the rotating mechanism of the mobile CBCT has the following significant defects: 1. Insufficient movement stability: The bearing support points of the traditional rotating mechanism have a small spacing, and it is difficult to meet the stability requirements when installed vertically. Especially in a mobile scenario, the vibration of the device easily causes uneven rotation speed.

[0004] 2. Poor exposure synchronization: When the rotation transmission device has a speed fluctuation due to long-term use, the timing of X-ray exposure cannot be accurately matched with the rotational movement, resulting in problems such as blurred and artifact-containing acquired images, seriously affecting the diagnostic accuracy.

[0005] 3. Single limit and buffer function: The existing limit mechanism can only achieve simple angle limitation and lacks a dynamic buffer mechanism. When rotating and positioning, it is easy to generate collision noise and vibration, further exacerbating the movement instability.

[0006] Therefore, there is an urgent need to design a compensation method and system that can monitor the rotational movement state in real time and dynamically adjust the X-ray exposure based on the feedback data to solve the above technical problems. Summary of the Invention

[0007] To overcome the deficiencies in the above prior art, the purpose of the present invention is to provide a method and system for compensating the rotational movement of a mobile CBCT, which can dynamically adjust the X-ray exposure parameters by monitoring the movement data of the rotating mechanism in real time, ensure the synchronization of the rotational movement and the exposure process, and improve the image acquisition quality and the operation stability of the device.

[0008] To achieve the above purpose and other related purposes, the technical solution provided by the present invention is: A method for compensating the rotational movement of a mobile CBCT, including the following steps: S1: Motion data acquisition: Real-time acquisition of the motion data of the rotating shaft through a motion monitoring module; S2: Motion state analysis: Analyze the collected motion data to determine whether the shaft is in a stable operation state; S3: Compensation signal generation: when it is determined that the motion is not stable, a compensation control signal for adjusting the rotation speed of the driving mechanism and the X-ray exposure parameters is generated; S4: driving and exposure adjustment: the driving mechanism and the X-ray adjustment unit adjust the rotation speed of the shaft and the X-ray exposure parameters respectively according to the compensation control signal; S5: Closed-loop feedback control: Continuously execute the data collection, analysis and adjustment process to achieve dynamic synchronous control.

[0009] The preferred technical solution is: the motion data includes a rotation angle θ, an angular velocity ω and an angular acceleration α; in the motion state analysis step, the motion smoothness is determined by judging whether ω exceeds a preset angular velocity threshold range [ω_min, ω_max] and whether |α| exceeds a preset angular acceleration threshold |α_max|.

[0010] The preferred technical solution is: use PID control algorithm to calculate the speed adjustment Δn of the drive mechanism, the formula is: Δn=Kp・Δω+Ki・∫Δωdt+Kd・dΔω / dt, where Δω=ω-ω_avg, ω_avg is the set average angular velocity, Kp, Ki, Kd are PID control parameters.

[0011] The preferred technical solution is: in S3, the target angle θ_target at the next exposure moment is calculated by a motion trajectory prediction model, and an exposure trigger signal delay time Δt is generated, and the motion trajectory prediction model is a Kalman filter model trained based on historical motion data.

[0012] The preferred technical solution is: the adjustment of the X-ray exposure parameters includes dynamically adjusting the exposure intensity I, and the adjustment formula is: I=I0・(ω_avg / ω), where I0 is the set benchmark exposure intensity and ω is the current angular velocity.

[0013] A mobile CBCT rotational motion compensation system is implemented based on the above method, comprising a frame, a bearing seat and a rotating shaft arranged on the frame, one end of the rotating shaft is connected to an imaging scanning mechanism, and the other end is transmission-connected to a driving mechanism, and also comprises a motion monitoring module, a motion compensation module and an X-ray adjustment unit; the motion monitoring module is used to collect motion data of the rotating shaft in real time; the motion compensation module is signal-connected to the motion monitoring module, and is used to generate a compensation control signal based on the motion data; the X-ray adjustment unit is signal-connected to the motion compensation module, and is used to adjust the X-ray exposure parameters according to the compensation control signal.

[0014] The preferred technical solution is as follows: The motion monitoring module includes a circular grating and an optoelectronic switch III. The circular grating is coaxially and fixedly arranged on the outer periphery of the rotating shaft. The optoelectronic switch III is arranged on the frame and used to detect the motion data of the circular grating. The motion data includes at least the rotation angle, angular velocity, and angular acceleration.

[0015] The preferred technical solution is as follows: The driving mechanism includes a driving pulley, a driven pulley, a transmission belt, and a driving motor. The driven pulley is coaxially and fixedly arranged at the end of the rotating shaft through a pulley mounting seat. The driving motor is signal-connected to the motion compensation module and used to adjust the rotating speed of the rotating shaft according to the compensation control signal.

[0016] The preferred technical solution is as follows: The X-ray adjustment unit includes an exposure control module and a radiation source. The exposure control module is used to generate an exposure trigger signal according to the compensation control signal. The radiation source is used to adjust the exposure time and exposure intensity according to the exposure trigger signal.

[0017] The preferred technical solution is as follows: It further includes a limiting mechanism and a buffering mechanism arranged between the rotating shaft and the frame. The limiting mechanism is used to limit the rotation range of the rotating shaft. The buffering mechanism is used to reduce the collision noise and vibration when the rotating shaft is limited.

[0018] Due to the application of the above technical solutions, the beneficial effects of the present invention are as follows: The mobile CBCT rotation motion compensation method and system proposed by the present invention break through the technical bottlenecks of the traditional CBCT rotation mechanism in terms of stability, synchronism, and environmental adaptability through the collaborative innovation of the limiting, buffering, and motion compensation mechanisms. Its core advantages are as follows: Through the dual control of the optoelectronic switch and mechanical limit, the sub-degree accuracy of angle limit and exposure synchronization is achieved; The design of tension spring buffering and belt drive overload protection significantly improves the impact resistance and service life of the equipment; The modular structure and parameter adjustable design support rapid adaptation to multiple scenarios and promote the popular application of mobile CBCT in the fields of emergency, surgery, etc. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the unassembled motion compensation structure of the mobile CBCT involved in the present invention.

[0020] Figure 2 It is a schematic diagram of the assembled motion compensation structure of the mobile CBCT involved in the present invention.

[0021] Figure 3 It is a matching diagram of the scanning speed and pulse exposure involved in the present invention. Detailed Embodiments

[0022] The following specific embodiments illustrate the implementation manners of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] Please refer to Figures 1 - 3 . It should be noted that in the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and cannot be understood as indicating or implying relative importance. The terms "horizontal", "vertical", "overhanging", etc. do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0024] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0025] Embodiment: According to a general technical concept of the present invention, a method for compensating the rotational motion of a mobile CBCT is provided, including the following steps: S1: Motion data acquisition: Real-time acquisition of the motion data of the rotating shaft through a motion monitoring module; S2: Motion state analysis: Analyze the acquired motion data to determine whether the rotating shaft is in a stable running state; S3: Compensation signal generation: When it is determined that the motion is in an unstable state, generate a compensation control signal for adjusting the rotational speed of the driving mechanism and the X-ray exposure parameters; S4: Driving and exposure adjustment: The driving mechanism and the X-ray adjustment unit respectively adjust the rotational speed of the rotating shaft and the X-ray exposure parameters according to the compensation control signal; S5: Closed-loop feedback control: Continuously and circularly execute the processes of data acquisition, analysis, and adjustment to achieve dynamic synchronous control.

[0026] In an exemplary embodiment of the present invention, the motion data includes the rotation angle θ, the angular velocity ω, and the angular acceleration α. In the motion state analysis step, the motion smoothness is determined by judging whether ω exceeds the preset angular velocity threshold range [ω_min, ω_max] and whether |α| exceeds the preset angular acceleration threshold |α_max|.

[0027] In an exemplary embodiment of the present invention, the PID control algorithm is used to calculate the rotational speed adjustment amount Δn of the driving mechanism. The formula is Δn = Kp・Δω + Ki・∫Δωdt + Kd・dΔω / dt, where Δω = ω - ω_avg, ω_avg is the set average angular velocity, and Kp, Ki, and Kd are the PID control parameters.

[0028] In an exemplary embodiment of the present invention, in S3, the target angle θ_target at the next exposure moment is calculated through the motion trajectory prediction model, and the exposure trigger signal delay time Δt is generated. The motion trajectory prediction model is a Kalman filter model trained based on historical motion data.

[0029] In an exemplary embodiment of the present invention, the adjustment of the X-ray exposure parameters includes dynamically adjusting the exposure intensity I. The adjustment formula is: I = I0・(ω_avg / ω), where I0 is the set reference exposure intensity and ω is the current angular velocity.

[0030] Velocity Compensation and Exposure Synchronization Based on PID Control System Configuration Frame Assembly: An aluminum alloy frame structure is adopted. The bearing housing is internally provided with deep groove ball bearings. The diameter of the rotating shaft is φ30mm, and the material is 45# steel.

[0031] Driving Mechanism: The driving motor is a servo motor (power 200W, rated speed 3000r / min). The diameter of the driving pulley is φ50mm, the diameter of the driven pulley is φ100mm, and the transmission ratio is 2:1, achieving a maximum rotating speed of the rotating shaft of 1500r / min.

[0032] Motion Monitoring Module: 100 light-transmitting teeth are evenly distributed on the outer circumference of the circular grating. The photoelectric switch three (model E3Z-D62) is used to detect the passing frequency of the tooth gaps, and the angular velocity ω = 2πf / n (f is the frequency, n is the number of teeth) is calculated.

[0033] Motion Compensation Module: An STM32F407 microcontroller is adopted, which internally integrates the PID control algorithm and the Kalman filter prediction model.

[0034] X-ray Adjustment Unit: The ray source model is DXR-300. The adjustable range of the exposure time is 0.1 - 100ms, and the adjustable range of the exposure intensity is 10 - 300mA.

[0035] Compensation method steps: 1. Initialization settings: Preset angular velocity threshold range [ω_min, ω_max] = [490 r / min, 510 r / min] (target average rotational speed ω_avg = 500 r / min).

[0036] Angular acceleration threshold |α_max| = 50 r / min².

[0037] PID parameter settings: Kp = 0.5, Ki = 0.1, Kd = 0.05.

[0038] 2. Motion data acquisition: The optoelectronic switch three detects the circular grid tooth gap signal in real time, and the microcontroller calculates the current angular velocity ω and angular acceleration α. For example, at a certain moment, the detected frequency f = 83.3 Hz, then ω = 2π×83.3 / 100 ≈ 5.23 rad / s ≈ 500 r / min (initial steady state).

[0039] 3. Motion state analysis: When the rotation shaft vibrates and causes ω = 520 r / min (exceeding the threshold upper limit), and α = 60 r / min² (exceeding the threshold), it is determined that the motion is unstable.

[0040] 4. Compensation signal generation: Speed compensation: Δω = 520 - 500 = 20 r / min Δn = 0.5×20 + 0.1×∫20dt + 0.05×(dΔω / dt). Assuming the integration time t = 0.1 s and the differential link dΔω / dt = 0 (constant speed deviation), then Δn = 10 + 0.2 + 0 = 10.2 r / min, and the speed of the control drive motor is reduced by 10.2 r / min.

[0041] Exposure synchronization: According to the current angle θ = 30°, predict the next exposure angle θ_target = 45°, calculate the motion trajectory through the Kalman filter model. Assuming that the current angular velocity deviation causes a time delay Δt = 5 ms to reach θ_target, generate an exposure trigger signal delay of 5 ms.

[0042] 5. Drive and exposure adjustment: The servo motor receives the speed reduction signal and gradually restores the rotation speed of the rotation shaft to 500 r / min through the transmission belt.

[0043] The X-ray adjustment unit receives the delayed exposure signal and triggers exposure at θ=45°, while adjusting the exposure intensity I=I0×(500 / 520)=0.96I0 according to ω=520r / min (assuming I0=200mA, then I=192mA).

[0044] 6. Closed-loop feedback: Continuously monitor motion data and update the compensation control signal every 10ms until the motion state is stable.

[0045] Experimental results Speed recovery time: about 200ms, speed fluctuation after stabilization ±2r / min.

[0046] Exposure synchronization error: Angle deviation <0.5°, image resolution increased to 2lp / mm (traditional method is 1.5lp / mm).

[0047] like Figures 1 to 3 As shown, according to an overall technical concept of the present invention, a mobile CBCT rotational motion compensation system is also provided, which is implemented based on the above method, including a frame 1, a bearing seat and a rotating shaft 2 arranged on the frame 1, one end of the rotating shaft 2 is connected to the imaging scanning mechanism 3, and the other end is connected to the driving mechanism in a transmission manner, and also includes a motion monitoring module, a motion compensation module and an X-ray adjustment unit; the motion monitoring module is used to collect the motion data of the rotating shaft 2 in real time; the motion compensation module is connected to the motion monitoring module by signal, and is used to generate a compensation control signal based on the motion data; the X-ray adjustment unit is connected to the motion compensation module by signal, and is used to adjust the X-ray exposure parameters according to the compensation control signal. The motion compensation system monitors the motion data through the circular grid 61 and the photoelectric switch three 62, and dynamically adjusts the exposure parameters by linkage with the X-ray adjustment unit, the exposure synchronization error is ≤0.8°, the image signal-to-noise ratio is improved by 15%-20%, and the image acquisition validity is effectively guaranteed. The photoelectric switch three 62 transmits the motion data to the X-ray adjustment unit, and the unit adjusts the exposure parameters according to the preset algorithm (such as the synchronization trigger threshold) to realize the real-time closed-loop control of "speed fluctuation-exposure delay-energy compensation". When the shaft speed fluctuates by ±10%, the exposure trigger angle error is ≤0.8°, ensuring that the X-ray is accurately projected at the preset anatomical position and avoiding image artifacts (such as ring artifacts and motion blur) caused by asynchronous movement. The exposure intensity can be adjusted in real time according to the speed (such as automatically increasing the tube current when the speed increases), so that the X-ray dose per unit angle remains constant, and the image signal-to-noise ratio (SNR) is improved by 15%-20%.

[0048] like Figures 1 to 3As shown in the figure, in an exemplary embodiment of the present invention, the motion monitoring module includes a circular grille 61 and an optoelectronic switch III 62. The circular grille 61 is coaxially and fixedly arranged on the outer periphery of the rotating shaft 2. The optoelectronic switch III 62 is arranged on the frame 1 and is used to detect the motion data of the circular grille 61. The motion data at least includes the rotation angle, angular velocity, and angular acceleration.

[0049] As Figures 1 to 3 shown in the figure, in an exemplary embodiment of the present invention, the driving mechanism includes a driving pulley 71, a driven pulley 72, a transmission belt 73, and a driving motor. The driven pulley 72 is coaxially and fixedly arranged at the end of the rotating shaft 2 through a pulley mounting seat. The driving motor is fixedly arranged on the frame 1 and is used to drive the driving pulley 71 to rotate. The transmission belt 73 is wound around the driving pulley 71 and the driven pulley 72. The driving motor is in signal connection with the motion compensation module and is used to adjust the rotating speed of the rotating shaft according to the compensation control signal. The driving mechanism adopts a belt drive scheme of driving pulley 71 + driven pulley 72 + transmission belt 73. The driven pulley 73 is coaxially fixed with the stop ring through a pulley mounting seat. The transmission ratio can be flexibly adjusted by replacing the pulleys (such as 1:1.5 - 1:3).

[0050] As Figures 1 to 3 shown in the figure, in an exemplary embodiment of the present invention, the X-ray adjustment unit includes an exposure control module and a radiation source. The exposure control module is used to generate an exposure trigger signal according to the compensation control signal. The radiation source is used to adjust the exposure time and exposure intensity according to the exposure trigger signal.

[0051] As Figures 1 to 3 shown in the figure, in an exemplary embodiment of the present invention, it further includes a limiting mechanism and a buffer mechanism arranged between the rotating shaft 2 and the frame 1. The limiting mechanism is used to limit the rotation range of the rotating shaft 2, and the buffer mechanism is used to reduce the collision noise and vibration when the rotating shaft 2 is limited.

[0052] Among them, the limiting mechanism is composed of a stop ring 41, a limiting block I 42, a limiting block II 43, an optoelectronic switch I 44, and an optoelectronic switch II 45. The stop ring 41 is coaxially and fixedly arranged at the end of the rotating shaft 2. A stop protrusion 411 extending outward is formed at the edge of the stop ring 41. The limiting block I 42 and the limiting block II 43 are fixedly arranged on the frame 1 and are located outside the stop ring 41. The stop protrusion 411 is located between the limiting block I 42 and the limiting block II 43. The optoelectronic switch I 44 and the optoelectronic switch II 45 are fixedly arranged on the frame 1 and are located between the limiting block I 42 and the limiting block II 43. The optoelectronic switch I 44 and the optoelectronic switch II 45 are used to detect the motion state of the stop protrusion 411 between the limiting block I 42 and the limiting block II 43. Through the cooperation of the stop ring, the limiting blocks, and the optoelectronic switches, the limiting mechanism can limit the rotation range of the rotating shaft. Combined with the linkage of the driving mechanism and the optoelectronic switch, precise angle adjustment and smooth start and stop are realized, and the positioning error ≤ 0.5°.

[0053] The buffer mechanism is composed of a limit ring 51, a mounting seat 52 and a tension spring 53. The limit ring 51 is sleeved on the outer periphery of the rotating shaft 2. An outwardly extending connecting projection 511 is formed on the outer periphery of the limit ring 51. The mounting seat 52 is fixedly arranged on the frame 1. One end of the tension spring 53 is connected to the mounting seat 52, and the other end is connected to the connecting projection 511. The design of the tension spring of the buffer mechanism reduces the collision noise from 75 dB to below 55 dB and the vibration acceleration from 10 g to within 3 g, reduces the impact on precision components, and improves stability.

[0054] Therefore, the present invention has the following advantages: The mobile CBCT rotation motion compensation method and system proposed by the present invention break through the technical bottlenecks of the traditional CBCT rotation mechanism in terms of stability, synchronization and environmental adaptability through the collaborative innovation of three mechanisms: limit, buffer and motion compensation. Its core advantages are as follows: through the dual control of the photoelectric switch and mechanical limit, the sub-degree accuracy of angle limit and exposure synchronization is achieved; the design of tension spring buffer and belt drive overload protection significantly improves the impact resistance and service life of the equipment; the modular structure and parameter adjustable design support rapid adaptation to multiple scenarios and promote the popular application of mobile CBCT in the fields of emergency, surgery, etc.

[0055] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for compensating the rotational movement of mobile CBCT, characterized in that, Including the following steps: S1: Motion data acquisition: Real-time acquisition of the motion data of the rotating shaft through the motion monitoring module; S2: Motion state analysis: Analyze the acquired motion data to determine whether the rotating shaft is in a stable running state; S3: Compensation signal generation: When it is determined that the motion is in an unstable state, generate a compensation control signal for adjusting the rotational speed of the drive mechanism and the X-ray exposure parameters; S4: Drive and exposure adjustment: The drive mechanism and the X-ray adjustment unit respectively adjust the rotational speed of the rotating shaft and the X-ray exposure parameters according to the compensation control signal; S5: Closed-loop feedback control: Continuously and circularly execute the data acquisition, analysis and adjustment processes to achieve dynamic synchronous control.

2. The mobile CBCT rotation motion compensation method according to claim 1, wherein: The motion data includes the rotation angle θ, the angular velocity ω and the angular acceleration α. In the motion state analysis step, the motion stability is determined by judging whether ω exceeds the preset angular velocity threshold range [ω_min, ω_max] and whether |α| exceeds the preset angular acceleration threshold |α_max|.

3. A method for compensating the rotational motion of a mobile CBCT, according to claim 2, wherein: The PID control algorithm is used to calculate the rotational speed adjustment amount Δn of the drive mechanism. The formula is: Δn = Kp・Δω + Ki・∫Δωdt + Kd・dΔω / dt, where Δω = ω - ω_avg, ω_avg is the set average angular velocity, and Kp, Ki, and Kd are the PID control parameters.

4. A mobile CBCT rotation motion compensation method according to claim 1, characterized in that: In S3, the target angle θ_target at the next exposure moment is calculated through the motion trajectory prediction model, and the exposure trigger signal delay time Δt is generated. The motion trajectory prediction model is a Kalman filter model trained based on historical motion data.

5. A mobile CBCT rotation motion compensation method according to claim 1, characterized in that: The adjustment of the X-ray exposure parameters includes dynamically adjusting the exposure intensity I. The adjustment formula is: I = I0・(ω_avg / ω), where I0 is the set reference exposure intensity and ω is the current angular velocity.

6. A mobile CBCT rotational motion compensation system implemented based on the method according to any one of claims 1-5, characterized in that: It includes a frame, a bearing seat provided on the frame and a rotating shaft. One end of the rotating shaft is connected to the imaging scanning mechanism, and the other end is in transmission connection with the drive mechanism. It also includes a motion monitoring module, a motion compensation module and an X-ray adjustment unit; the motion monitoring module is used to acquire the motion data of the rotating shaft in real time; the motion compensation module is signal-connected to the motion monitoring module and is used to generate a compensation control signal based on the motion data; the X-ray adjustment unit is signal-connected to the motion compensation module and is used to adjust the X-ray exposure parameters according to the compensation control signal.

7. A mobile CBCT rotational motion compensation system according to claim 6, characterized in that: The motion monitoring module includes a circular grating and a photoelectric switch three. The circular grating is coaxially fixed on the outer periphery of the rotating shaft, and the photoelectric switch three is provided on the frame and is used to detect the motion data of the circular grating. The motion data at least includes the rotation angle, the angular velocity and the angular acceleration.

8. A mobile CBCT rotational motion compensation system according to claim 6, characterized in that: The drive mechanism includes a driving pulley, a driven pulley, a transmission belt and a driving motor. The driven pulley is coaxially fixed at the end of the rotating shaft through a pulley mounting seat. The driving motor is signal-connected to the motion compensation module and is used to adjust the rotational speed of the rotating shaft according to the compensation control signal.

9. A mobile CBCT rotational motion compensation system according to claim 6, characterized in that: The X-ray adjustment unit includes an exposure control module and a radiation source. The exposure control module is configured to generate an exposure trigger signal according to a compensation control signal, and the radiation source is configured to adjust the exposure time and exposure intensity according to the exposure trigger signal.

10. A mobile CBCT rotational motion compensation system according to claim 6, characterized in that: It further includes a limiting mechanism and a buffer mechanism disposed between the rotating shaft and the frame. The limiting mechanism is used to limit the rotation range of the rotating shaft, and the buffer mechanism is used to reduce the collision noise and vibration when the rotating shaft is limited.

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