Collimator and control system thereof

Abstract

The application discloses a collimator and a control system thereof, the collimator comprising at least one grating assembly, each grating assembly comprising a plurality of grating leaves for blocking a beam; the control system comprising: a third adjusting device, the third adjusting device comprising a third grating encoder, a fourth grating encoder and a plurality of third adjusting units; each third adjusting unit being drivingly connected to one grating leaf, the third grating encoder and the fourth grating encoder being connected to the grating leaf; and a control module, the control module being connected to the plurality of third adjusting units through a CANBUS bus and being configured to adjust the positions of the grating leaves according to a primary feedback signal collected by the third grating encoder and a secondary feedback signal collected by the fourth grating encoder, so as to adjust the shape of the proton beam to match the shape of a tumor. The collimator and the control system thereof can adjust the positions of the grating leaves in real time according to the feedback signals, and ensure efficient and dynamic adjustment of the proton beam.

Description

Technical Field

[0001] This invention relates to the field of high-end medical device technology, and in particular to a collimator and its control system. Background Technology

[0002] Proton therapy is an advanced radiotherapy technique that utilizes the Bragg peak characteristics of proton beams to precisely kill tumor tissue while minimizing damage to surrounding healthy tissues. Compared to traditional X-ray radiotherapy, proton therapy offers higher dose distribution precision, delivering a maximum dose to the tumor area while rapidly decreasing the dose in healthy tissues around the tumor, thus significantly reducing radiation damage to normal tissues. This characteristic makes proton therapy particularly suitable for treating tumors located near critical organs or tissues, such as brain tumors, eye tumors, and childhood tumors.

[0003] The high precision requirements of proton therapy also present technical challenges. To fully utilize the Bragg peak characteristics of the proton beam, it is essential to ensure that the shape and position of the proton beam precisely match the shape and location of the tumor. The collimator is a key component of proton therapy equipment, its main function being to adjust the shape of the proton beam to match the shape of the tumor. Through the collimator, the proton beam can be precisely guided to the tumor area while avoiding damage to surrounding healthy tissue. Traditional collimators typically employ a fixed grating system, adjusting the position of the grating blades manually or semi-automatically to form beams of different shapes. To further improve the collimator, this invention proposes a novel collimator and its control system. Summary of the Invention

[0004] The purpose of this invention is to provide a collimator and its control system, which can adjust the position of the grating blades in real time according to the feedback signal to ensure that the shape of the proton beam is dynamically adjusted according to the change of the tumor shape.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] On one hand, the present invention provides a control system for a collimator, the collimator including at least one grating assembly, each grating assembly including a plurality of grating blades, the grating blades being used to block the beam;

[0007] The control system includes:

[0008] The third adjustment device includes a third grating encoder, a fourth grating encoder, and a plurality of third adjustment units; each of the third adjustment units is driven and connected to one of the grating blades, and the third grating encoder and the fourth grating encoder are connected to the grating blades;

[0009] The control module is connected to multiple third adjustment units via a CANBUS bus and is configured to adjust the position of each grating blade according to the main feedback signal collected by the third grating encoder and the secondary feedback signal collected by the fourth grating encoder, so as to adjust the shape of the proton beam to match the shape of the tumor.

[0010] The beneficial effects of the above solution are: the present invention can adjust the position of the grating blades in real time according to the feedback signal, ensuring that the shape of the proton beam dynamically adjusts according to the change of the tumor shape. Specifically, through the dual feedback signals of the third and fourth grating encoders, the control system can precisely adjust the position of the grating blades, ensuring that the shape of the proton beam is highly matched with the shape of the tumor, thus improving the accuracy of treatment. Furthermore, the present invention can connect multiple third adjustment units via a CANBUS bus, and the system has modular characteristics, facilitating expansion and maintenance.

[0011] Furthermore, the third adjustment unit drives the grating blades to reciprocate along the C-axis direction;

[0012] The control system further includes:

[0013] A first adjustment device drives the grating assembly to reciprocate along the A-axis direction;

[0014] The second adjustment device drives the collimator to reciprocate along the B-axis direction;

[0015] The A-axis is perpendicular to the B-axis and the C-axis, and the B-axis and the C-axis intersect.

[0016] The beneficial effects of the above solution are as follows: Through three-axis motion control along the A, B, and C axes, the system can achieve multi-dimensional adjustment of the grating assembly and grating blades, ensuring a high degree of matching between the proton beam shape and the tumor shape. Furthermore, with the grating blades moving along the C-axis and the grating assembly moving along the A and B axes, the system can adapt to tumors of different shapes and locations, improving treatment flexibility.

[0017] Furthermore, the third adjustment unit includes a third linear motor, which is connected to the grating blades;

[0018] Furthermore, the first adjustment device includes a first rotary motor, a first rotary encoder, and a first grating encoder, wherein the first rotary encoder is connected to the first rotary motor, the first rotary motor is connected to the grating assembly, and the first grating encoder is connected to the grating assembly;

[0019] Furthermore, the second adjustment device includes a second rotary motor, a second rotary encoder, and a second grating encoder. The second rotary encoder is connected to the second rotary motor, the second rotary motor is connected to the grating assembly, and the second grating encoder is connected to the grating assembly.

[0020] The beneficial effects of the above solution are as follows: The present invention uses a rotary motor to drive the grating assembly through the first and second adjustment devices to adjust the position of the grating blades, and a linear motor to drive the grating blades through the third adjustment unit to further adjust the position of the grating blades. Furthermore, through the dual feedback of the rotary encoder and the grating encoder, the system can achieve high-precision position control, ensuring the accurate positioning of the grating blades.

[0021] Furthermore, the control module is connected to the first rotary motor, the second rotary motor, and / or the third linear motor via a CANBUS bus;

[0022] Furthermore, the control module is also configured to adjust the position of each grating component according to the main feedback signal collected by the first grating encoder and the secondary feedback signal collected by the first grating encoder;

[0023] Furthermore, the control module is also configured to adjust the position of each grating component according to the main feedback signal collected by the second grating encoder and the secondary feedback signal collected by the second grating encoder.

[0024] The beneficial effects of the above solution are: This invention achieves centralized control by connecting the first rotary motor, the second rotary motor, and the third linear motor via a CANBUS bus through a control module, ensuring the synchronization and coordination of multi-axis motion. Furthermore, the control module adjusts the position of the grating assembly based on feedback signals from the first and second grating encoders, ensuring high-precision control of the system.

[0025] Furthermore, the control module includes:

[0026] FPGA unit, wherein the FPGA unit is connected to each encoder;

[0027] A microprocessor, one end of which is connected to the FPGA unit and the other end of which is connected to the CANBUS bus.

[0028] The advantages of the above solution are: by combining an FPGA unit and a microprocessor, this invention can quickly process encoder feedback signals, ensuring that the system responds in real time to changes in the position of the grating blades and grating components. Furthermore, by connecting the motors and encoders via a CANBUS bus, the system achieves high integration and facilitates expansion and maintenance.

[0029] Furthermore, the control module is also configured to:

[0030] Obtain the shape of the tumor;

[0031] Based on TPS, a treatment plan is generated according to the shape of the tumor;

[0032] Based on LPA, the position of the grating blades is adjusted according to the treatment plan.

[0033] The beneficial effects of the above solution are: the present invention can generate personalized treatment plans based on the shape of the tumor, ensuring a high degree of matching between the shape of the proton beam and the tumor shape, thereby improving treatment efficacy. Furthermore, based on TPS (Treatment Planning System) and LPA (Leaf Positioning Algorithm), the system can automatically adjust the position of the grating blades, reducing manual intervention and improving treatment efficiency.

[0034] Furthermore, the treatment plan includes a TPS dynamic trajectory;

[0035] The adjustment of the position of the grating blades according to the treatment plan includes:

[0036] The current positions of multiple grating blades are fitted into a blade curve, and the grating blades are moved so that the blade curve coincides with the TPS dynamic trajectory.

[0037] The beneficial effects of the above solution are as follows: By fitting the current position of the grating blades to a blade curve and aligning it with the TPS dynamic trajectory, the system can dynamically adjust the proton beam shape, ensuring the precision of treatment. Furthermore, the motion path of the grating blades is optimized to ensure that the treatment target is achieved with minimal blade movement, reducing system energy consumption and mechanical wear.

[0038] Furthermore, the plurality of grating blades are arranged sequentially, with the grating blades at both ends of the grating assembly being the first blades and the grating blades in the middle of the grating assembly being the second blades;

[0039] The movable grating blades include:

[0040] First, move the first blade, then move the second blade, so that the grating blades of the multiple grating components sequentially form a closed blade curve, and the closed blade curve coincides with the TPS dynamic trajectory.

[0041] The beneficial effects of the above solution are as follows: By first moving the first blades at both ends of the grating assembly and then moving the second blade in the middle, the system can efficiently form a closed blade curve, ensuring that the shape of the proton beam highly matches the shape of the tumor. Furthermore, by optimizing the blade movement sequence, the system can reduce the movement of the internal blades, thereby reducing mechanical wear and energy consumption.

[0042] Furthermore, the movable grating blades include:

[0043] Based on PID control algorithm and feedforward control algorithm, the thrust is adjusted to compensate for mechanical load disturbance;

[0044] The PID control algorithm is used to adjust the motor current based on the difference between the actual position and the target position of the grating blade, so that the grating blade moves to the target position.

[0045] The feedforward control algorithm is used to apply thrust before the grating blades move to counteract inertia, friction and gravity interference during the movement of the grating blades.

[0046] The beneficial effects of the above solution are as follows: Through PID control and feedforward control algorithms, the system can dynamically adjust the thrust, compensate for mechanical load disturbances, and ensure that the grating blades move quickly and accurately to the target position. Furthermore, the feedforward control algorithm can counteract inertial, frictional, and gravitational disturbances, ensuring that the grating blades remain stable during movement.

[0047] Furthermore, the control system also includes a safety loop, which includes:

[0048] The hardware emergency stop circuit is used to stop the operation of the adjustment device in an emergency.

[0049] The overcurrent protection circuit is used to cut off the power supply when the motor current exceeds a set threshold.

[0050] The over-temperature protection circuit is used to automatically stop the adjustment device when the motor temperature exceeds the set threshold.

[0051] The software protection circuit is used to limit the movement range of the grating blades through the position soft limit function to prevent collisions or over-limit movement.

[0052] The beneficial effects of the above solution are: Through hardware emergency stop, overcurrent protection, overtemperature protection, and software protection, the system can immediately stop operation in emergency situations, preventing equipment damage and personal injury. Furthermore, through the position soft limit function, the system can limit the movement range of the grating blades, preventing collisions or over-limit movement and ensuring safe equipment operation.

[0053] Furthermore, the control system also includes:

[0054] The self-diagnostic circuit monitors the motor coil impedance, motor temperature, and motor vibration spectrum in real time.

[0055] The beneficial effects of the above solution are as follows: By monitoring the motor coil impedance, temperature, and vibration spectrum in real time, the self-diagnostic circuit of this invention can predict motor faults (such as bearing wear, coil aging, etc.) and take measures in advance to avoid equipment damage. In addition, the self-diagnostic circuit can trigger an alarm or shutdown when an anomaly is detected, ensuring the safe operation of the system and reducing downtime.

[0056] In a second aspect, the present invention provides a collimator for use in proton therapy equipment;

[0057] The collimator includes the aforementioned control system.

[0058] The beneficial effects of the above solution are: the present invention can adjust the position of the grating blades in real time according to the shape and location of the tumor through the adaptive collimator of the proton therapy device, so as to ensure that the shape of the proton beam is highly matched with the shape of the tumor and improve the accuracy of treatment.

[0059] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0060] This invention can adjust the position of the grating blades in real time based on feedback signals, ensuring that the shape of the proton beam dynamically adjusts according to changes in the tumor shape. Specifically, through dual feedback signals from the third and fourth grating encoders, the control system can precisely adjust the position of the grating blades, ensuring a high degree of match between the proton beam shape and the tumor shape, thus improving treatment accuracy. Furthermore, this invention can connect multiple third adjustment units via a CANBUS bus, giving the system modular characteristics for easy expansion and maintenance. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of the control system of the collimator according to an embodiment of the present invention.

[0062] Figure 2 This is another structural schematic diagram of the control system of the collimator according to an embodiment of the present invention.

[0063] Figure 3 This is a schematic diagram of the adjustment device according to an embodiment of the present invention.

[0064] Figure 4 This is a schematic diagram of the structure of the first blade and the second blade in an embodiment of the present invention.

[0065] In the diagram: 11, first blade; 12, second blade; 13, blade curve; 14, channel; 30, second adjustment device; 41, first adjustment device; 100, third adjustment device. Detailed Implementation

[0066] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0067] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0068] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] The collimator of this invention is an adaptive collimator (AA) used in proton therapy equipment to adjust the shape of the proton beam to match the shape of the tumor.

[0070] In application, the collimator includes at least one grating assembly; preferably, the collimator of this application includes two grating assemblies arranged opposite each other.

[0071] In practical applications, each grating assembly includes multiple grating blades. These blades are used to block the beam, and the combination of multiple grating blades can adjust the shape of the proton beam. Furthermore, the multiple grating blades are arranged sequentially, with the grating blades at both ends of the grating assembly being the first blades 11, and the grating blade in the middle of the grating assembly being the second blades 12. Preferably, each grating assembly includes seven grating blades.

[0072] refer to Figure 3 The control system of the present invention includes a third adjustment device 100 and a control module. Further, the control system of the present invention may also include a first adjustment device 41 and / or a second adjustment device 30. Preferably, the first adjustment device 41 is a set, and the second adjustment device 30 is two sets. Further, the control system of the present invention may also include a safety circuit and / or a self-diagnostic circuit.

[0073] When applying, refer to Figure 1 and Figure 2 The control system of the present invention may further include: a main control computer, which is connected to a control module.

[0074] The third adjustment device 100 of the present invention includes a third grating encoder, a fourth grating encoder, and a plurality of third adjustment units. Preferably, the third adjustment device 100 includes two groups, and each group of the third adjustment device 100 includes seven third adjustment units.

[0075] In application, each third adjustment unit drives and connects to one grating blade, and the third and fourth grating encoders are connected to the grating blade. Specifically, the third grating encoder is used to acquire the main feedback signal of the grating blade, and the fourth grating encoder is used to acquire the secondary feedback signal of the grating blade.

[0076] In practical applications, the third adjustment unit includes a third linear motor connected to grating blades. Specifically, the third linear motor drives the grating blades to reciprocate along the C-axis to adjust the shape of the proton beam so that it matches the shape of the tumor.

[0077] The first adjustment device 41 of the present invention drives the grating assembly to reciprocate along the A-axis direction, and the A-axis is perpendicular to the C-axis.

[0078] In application, the first adjustment device 41 includes a first rotary motor, a first rotary encoder, and a first grating encoder. The first rotary encoder is connected to the first rotary motor, the first rotary motor is connected to the grating assembly, and the first grating encoder is connected to the grating assembly.

[0079] The second adjustment device 30 of the present invention drives the collimator to reciprocate along the B-axis direction, the A-axis and the B-axis are perpendicular to each other, and the B-axis intersects the C-axis.

[0080] In application, the second adjustment device 30 includes a second rotary motor, a second rotary encoder, and a second grating encoder. The second rotary encoder is connected to the second rotary motor, the second rotary motor is connected to the grating assembly, and the second grating encoder is connected to the grating assembly.

[0081] refer to Figure 1 and Figure 2 The control module of the present invention includes an FPGA unit and a microprocessor.

[0082] In application, the FPGA unit is connected to each encoder; one end of the microprocessor is connected to the FPGA unit, and the other end is connected to the CANBUS bus. Furthermore, the microprocessor of the control module is connected to multiple third adjustment units via the CANBUS bus. Preferably, the microprocessor of the control module is connected to the first rotary motor, the second rotary motor, and / or the third linear motor via the CANBUS bus, and to each motor and encoder via the CANBUS bus, resulting in high system integration and ease of expansion and maintenance.

[0083] In practical applications, the collimator's control method includes: the control module acquiring feedback signals from each grating encoder in real time, and dynamically adjusting the motion state of each motor based on the feedback signals to ensure the grating blades move precisely to the target position. Further, the control module calculates the error between the actual position and the target position of the grating assembly based on the main and secondary feedback signals. Then, based on the position error, the current of the first rotary motor, the second rotary motor, and / or the third linear motor is adjusted to drive the grating assembly along the A-axis, B-axis, and / or drive the grating blades along the C-axis to move to the target position.

[0084] Preferably, the control module is configured to perform the following steps: adjust the position of each grating blade according to the main feedback signal collected by the third grating encoder and the secondary feedback signal collected by the fourth grating encoder; adjust the position of each grating component according to the main feedback signal collected by the first grating encoder and the secondary feedback signal collected by the first grating encoder; and adjust the position of each grating component according to the main feedback signal collected by the second grating encoder and the secondary feedback signal collected by the second grating encoder.

[0085] In some other embodiments, the control module is also configured to execute steps SS1 to SS3. Specifically, a personalized treatment plan is generated based on the shape of the tumor, ensuring that the shape of the proton beam highly matches the shape of the tumor, thereby improving treatment efficacy. Furthermore, based on TPS (Treatment Planning System) and LPA (Leaf Positioning Algorithm), the system can automatically adjust the position of the grating blades, reducing manual intervention and improving treatment efficiency.

[0086] Step SS1: Obtain the shape of the tumor.

[0087] When applying this technique, the shape of tumors in different organs is generally different, and the shape of tumors at different stages is also generally different.

[0088] Step SS2: Based on TPS (Treatment Planning System), generate a treatment plan according to the shape of the tumor.

[0089] When applied, a treatment plan is generated based on the TPS (treatment planning system) to determine the target position of the grating blades.

[0090] Step SS3: Based on LPA (Leaf Positioning Algorithm), adjust the position of the grating blades according to the treatment plan. The treatment plan includes the TPS dynamic trajectory.

[0091] In application, step SS3 includes coarse adjustment, which involves planning the motion path of the grating blades based on LPA (blade positioning algorithm) to ensure the accuracy and efficiency of multi-axis coordinated motion. Specifically, the control module sends control commands via the CANBUS bus to ensure synchronous movement of the first rotary motor, the second rotary motor, and the third linear motor, avoiding collisions and over-limit movements.

[0092] In some preferred embodiments, step SS3 includes: fitting the current position of the plurality of grating blades into a blade curve 13, and moving the grating blades so that the blade curve coincides with the TPS dynamic trajectory.

[0093] The positions of the grating blades are initialized to ensure all blades are in their initial positions, and TPS dynamic trajectory data is loaded. Next, the control system uses an interpolation algorithm to fit the current positions of multiple grating blades into a continuous blade curve based on their current positions. The fitted blade curve is then compared with the TPS dynamic trajectory, and the deviation between the two is calculated.

[0094] When applying, refer to Figure 4 The process of moving the grating blades includes a fine-tuning step. This fine-tuning step involves optimizing the blade movement sequence to reduce internal blade movement, thereby lowering mechanical wear and energy consumption. Specifically, the first blade is moved first, followed by the second blade, allowing the grating blades of multiple grating assemblies to more quickly form the desired closed blade curve. The internal space enclosed by this blade curve is the space allowing the proton beam to pass through, i.e., channel 14. The closed blade curve of this invention coincides with the TPS dynamic trajectory, ensuring a high degree of matching between the proton beam shape and the tumor shape.

[0095] Based on the deviation calculation results, the position of the first blade is first adjusted to be as close as possible to the starting point of the TPS trajectory. While keeping the position of the first blade unchanged, the position of the second blade is adjusted so that the grating curve formed by it and the first blade coincides with the next segment of the TPS trajectory. Subsequent blades are adjusted sequentially, ensuring that the movement of each blade is based on the position of the previous blade, ultimately making the closed curve formed by all blades completely coincide with the TPS dynamic trajectory.

[0096] In practical applications, the adjustment process for moving the grating blades includes the following steps: adjusting the thrust based on PID control and feedforward control algorithms to compensate for mechanical load disturbances. Specifically, the PID control algorithm adjusts the motor current based on the difference between the actual and target positions of the grating blades, causing the grating blades to move to the target position. The feedforward control algorithm applies thrust before the grating blades move, counteracting inertia, friction, and gravity disturbances during the blades' movement.

[0097] In some embodiments, the required inertial compensation torque is calculated based on the motor's mass and acceleration requirements. Before motor startup, a corresponding feedforward torque command is applied to the drive system to counteract system inertial effects, thereby ensuring the motor can achieve a rapid dynamic response. The inertial compensation strategy can effectively reduce tracking errors during acceleration / deceleration phases and improve the transient response performance of the servo system.

[0098] In some other embodiments: a composite control strategy combining feedforward compensation and electromagnetic preload technology is employed to achieve millisecond-level dynamic response. The specific implementation includes the following steps: a dual-winding electromagnetic actuator is used, and the compensation winding is pre-excited before the motion command is issued to establish a reverse electromagnetic field to counteract mechanical lag. The control flow is as follows: 1) Based on the acceleration command given by the motion planning module, the reference value of the compensation winding current is calculated in real time; 2) The main drive winding and the compensation winding are synchronously excited according to the current command value; 3) After the rotor starts moving, a ramp function is used to linearly demagnetize the compensation current; 4) After entering the steady-state operation stage, the system switches to a closed-loop speed control mode based on a PID algorithm. This invention, by actively counteracting the influence of the system's electromechanical time constant, can shorten the step response time to less than 5ms.

[0099] In some embodiments, the required friction compensation force is calculated based on the frictional characteristics of the motor (including the coefficient of viscous friction and Coulomb friction) and the target speed:

[0100] Fcomp=Fc·sgn(vref)+Bv·vref

[0101] Where Fcomp is the required frictional compensation force; Fc is the Coulomb friction; sgn(vref) is the sign function of the velocity direction; Bv is the viscous friction coefficient; and vref is the target velocity. Before the motor moves, a corresponding feedforward compensation current, Icomp = Fcomp / Kt (Kt is the motor torque constant), is applied through the current loop to counteract the nonlinear friction during movement, ensuring smooth operation at low speeds and dynamic response at high speeds.

[0102] In some other embodiments, nanoscale smooth motion is achieved through dynamic friction modeling and feedforward compensation. For example, the LuGre friction model is used, comprehensively considering static friction, Coulomb friction, viscous friction, and the Stribeck effect. Specifically, the frictional characteristics of the motor are measured to determine the viscous friction coefficient and the Coulomb friction coefficient; the viscous friction compensation force and the Coulomb friction compensation force are calculated based on the target motion speed; the compensation force is converted into a feedforward current and applied through a current loop; when the speed crosses zero, a high-frequency micro-amplitude jitter signal is superimposed to reduce the hysteresis effect caused by static friction; based on position / velocity feedback, the feedforward gain is adjusted online to ensure nanoscale motion smoothness.

[0103] In some embodiments, the required gravity compensation force is calculated based on the mass of the motor and the gravitational acceleration; before the position command is issued, an equivalent compensation current is applied through the feedforward channel of the servo driver, that is, before the motor moves, a corresponding feedforward thrust is applied to counteract the gravitational influence when the motor moves in the vertical direction, so as to ensure that the motor can accurately control the position.

[0104] In some other embodiments: full gravity compensation is achieved through a pneumatic balancing cylinder and model feedforward. Specifically, upon power-up, the pressure in the upper and lower chambers of the balancing cylinder is adjusted to the equilibrium value via a proportional valve. The air path is switched via a high-speed solenoid valve according to the direction of the motion command; the compensation force is updated based on real-time data from the load sensor; the proportional valve compensation current is calculated via a feedforward controller; simultaneously, a pressure tolerance band is set to prevent oscillation, and a rapid exhaust valve is triggered in case of emergency stop.

[0105] In some preferred embodiments, after individually optimizing the PID control and feedforward control, comprehensive optimization can be performed to ensure optimal system performance in speed and position control. Specifically, the actual speed response of the motor is acquired, and the PID and feedforward control parameters are adjusted to ensure that the actual speed can quickly track the target speed without significant overshoot or oscillation. The actual position response of the motor is acquired, and the PID and feedforward control parameters are adjusted to ensure that the actual position can accurately track the target position without significant overshoot or oscillation.

[0106] The safety circuit of this invention includes: a hardware emergency stop circuit, an overcurrent protection circuit, an overtemperature protection circuit, and a software protection circuit.

[0107] In application, the hardware emergency stop circuit is used to stop the operation of the adjustment device in an emergency; the overcurrent protection circuit is used to cut off the power supply when the motor current exceeds the set threshold; the overtemperature protection circuit is used to automatically stop the operation of the adjustment device when the motor temperature exceeds the set threshold; and the software protection circuit is used to limit the movement range of the grating blades through the position soft limit function to prevent collisions or over-limit movement.

[0108] The self-diagnostic circuit of this invention monitors the motor coil impedance, motor temperature, and motor vibration spectrum in real time.

[0109] In summary, this invention can adjust the position of the grating blades in real time based on feedback signals, ensuring that the shape of the proton beam dynamically adjusts according to changes in the tumor shape. Specifically, through dual feedback signals from the third and fourth grating encoders, the control system can precisely adjust the position of the grating blades, ensuring a high degree of match between the proton beam shape and the tumor shape, thus improving treatment accuracy. Furthermore, this invention can connect multiple third adjustment units via a CANBUS bus, giving the system modular characteristics for easy expansion and maintenance.

[0110] In some embodiments, the present invention also provides a radiotherapy device, including the collimator described above, a particle accelerator for outputting a particle beam, and one or more scanning magnets for moving the particle beam relative to the patient's irradiation target, i.e., the tumor portion; the particle accelerator is capable of reciprocating circumferential motion driven by a rotating gantry, and the collimator is positioned between the one or more scanning magnets and the patient. In this embodiment, the collimator fits different target shapes for the channel, and the particle beam, after passing through the collimator, performs radiotherapy on the patient's treatment site according to the set target shape. The particles can be protons or heavy ions. The radiotherapy device can be the aforementioned proton therapy device.

[0111] This invention also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the aforementioned collimator control method in this invention.

[0112] This invention also provides a computer-readable storage medium for storing a computer program. When the computer program is executed, it implements the steps of the control method described in the embodiments of this invention. The specific implementation method is consistent with the implementation method and the technical effects achieved in the aforementioned collimator control method embodiments, and some details will not be repeated here.

[0113] In this application, a readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The program product can take the form of any combination of one or more readable media. A readable medium can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0114] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0115] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0116] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0117] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0118] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A control system for a collimator, characterized in that, The collimator includes at least one grating assembly, each of the grating assemblies including a plurality of grating blades, the grating blades being used to block the beam; The control system includes: The third adjustment device (100) includes a third grating encoder, a fourth grating encoder, and a plurality of third adjustment units; each of the third adjustment units is driven to connect to one of the grating blades, and the third grating encoder and the fourth grating encoder are connected to the grating blades; The control module is connected to multiple third adjustment units via a CANBUS bus and is configured to adjust the position of each grating blade according to the main feedback signal collected by the third grating encoder and the secondary feedback signal collected by the fourth grating encoder, so as to adjust the shape of the proton beam. The plurality of grating blades are arranged sequentially, with the grating blades at both ends of the grating assembly being the first blades and the grating blades in the middle of the grating assembly being the second blades; the control module is further configured to: When adjusting the position of the grating blades, the first blade is moved first, and then the second blade is moved so that the grating blades of the multiple grating components form a closed blade curve, and the closed blade curve coincides with the TPS dynamic trajectory of the treatment plan.

2. The control system of the collimator according to claim 1, characterized in that, The third adjustment unit drives the grating blades to reciprocate along the C-axis direction; The control system further includes: The first adjustment device (41) drives the grating assembly to reciprocate along the A-axis direction; The second adjustment device (30) drives the collimator to reciprocate along the B-axis direction; The A-axis is perpendicular to the B-axis and the C-axis, and the B-axis and the C-axis intersect.

3. The control system of the collimator according to claim 2, characterized in that, The third adjustment unit includes a third linear motor, which is connected to the grating blades; And / or, the first adjustment device (41) includes a first rotary motor, a first rotary encoder and a first grating encoder, the first rotary encoder being connected to the first rotary motor, the first rotary motor being connected to the grating assembly, and the first grating encoder being connected to the grating assembly; And / or, the second adjustment device (30) includes a second rotary motor, a second rotary encoder and a second grating encoder, the second rotary encoder being connected to the second rotary motor, the second rotary motor being connected to the collimator, and the second grating encoder being connected to the collimator.

4. The control system of the collimator according to claim 3, characterized in that, The control module is connected to the first rotary motor, the second rotary motor, and / or the third linear motor via a CANBUS bus. And / or, the control module is further configured to: adjust the position of each grating component according to the main feedback signal collected by the first grating encoder and the secondary feedback signal collected by the first grating encoder; And / or, the control module is further configured to adjust the position of the collimator according to the main feedback signal acquired by the second grating encoder and the secondary feedback signal acquired by the second grating encoder.

5. The control system of the collimator according to claim 3, characterized in that, The control module includes: FPGA unit, wherein the FPGA unit is connected to each encoder; A microprocessor, one end of which is connected to the FPGA unit and the other end of which is connected to the CANBUS bus.

6. The control system of the collimator according to claim 3, characterized in that, The control module is also configured to: Obtain the shape of the tumor; Based on TPS, a treatment plan is generated according to the shape of the tumor; Based on the leaf positioning algorithm, the position of the grating leaf is adjusted according to the treatment plan.

7. The control system of the collimator according to claim 1, characterized in that, The control module is also configured to: Based on PID control algorithm and feedforward control algorithm, the thrust is adjusted to compensate for mechanical load disturbance; The PID control algorithm is used to adjust the motor current based on the difference between the actual position and the target position of the grating blade, so that the grating blade moves to the target position. The feedforward control algorithm is used to apply thrust before the grating blades move to counteract inertia, friction and gravity interference during the movement of the grating blades.

8. The control system of the collimator according to claim 1, characterized in that, The control system further includes a safety loop, which includes: The hardware emergency stop circuit is used to stop the operation of the adjustment device in an emergency. The overcurrent protection circuit is used to cut off the power supply when the motor current exceeds a set threshold. The over-temperature protection circuit is used to automatically stop the adjustment device when the motor temperature exceeds the set threshold. The software protection circuit is used to limit the movement range of the grating blades through the position soft limit function to prevent collisions or over-limit movement.

9. The control system of the collimator according to claim 3, characterized in that, The control system further includes: The self-diagnostic circuit monitors the motor coil impedance, motor temperature, and motor vibration spectrum in real time.

10. A collimator, characterized in that, Used in proton therapy equipment; The collimator includes the control system described in any one of claims 1 to 9.

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