Flash beam dose control method and related equipment

Abstract

The present invention discloses a Flash beam dose control method and related equipment, and relates to the technical field of particle therapy, wherein the method comprises: obtaining a Flash beam output dose requirement; controlling the number of pulse periods of an output beam charge within a preset time through a Flash debugging mode; and / or controlling the pulse width of an ion source voltage through a pulse width mapping curve to achieve control of the Flash beam output dose rate; by accurately controlling the number of pulse periods of the output beam charge and the pulse width of the ion source voltage, accurate control of the Flash beam output dose rate can be achieved; and without additionally adding a shielding function to a proton machine room, the Flash dose can be debugged in a conventional proton machine room, which is conducive to the realization of particle Flash radiotherapy.

Description

Technical Field

[0001] The present invention relates to the technical field of particle therapy, and in particular to a Flash beam dose control method and related equipment. Background Art

[0002] Flash radiotherapy (also known as flash therapy) refers to the delivery of extremely high doses of radiation to the entire treatment volume in less than one second. Early preclinical studies have shown that protons can more effectively concentrate the energy of radiation on the tumor target area that needs treatment, significantly protect healthy tissues, improve local tumor control rates, and greatly reduce radiation complications of normal organs and tissues.

[0003] However, the implementation of flash radiotherapy technology faces a series of challenges, the most important of which is the issue of radiation safety; since flash radiotherapy involves releasing a very large dose of radiation in a very short time through a flash beam, that is, a particle beam with an extremely high dose rate, this places extremely high demands on radiation shielding walls. In order to ensure that the radiation dose rate outside the machine room during the treatment meets safety standards, the radiation shielding wall needs to be thick enough to provide adequate protection, resulting in a larger floor space for the wall and increased capital investment in machine room construction.

[0004] Taking the proton therapy system commissioning room as an example, according to the radiation protection standards, there are clear regulations on dose rate control levels in different locations (such as outside the shielding walls around the room, outside the entrance protection door, outside the room roof and outside the room floor); in order to meet these requirements, hospitals and / or enterprises must consider radiation shielding issues when designing and constructing the room.

[0005] In the application of flash radiotherapy technology, in order to achieve a dose rate control level that meets safety standards, there are two main solutions: one is to design complex flash radiation protection shielding equipment, which requires special materials and a lot of R&D investment; the other is to use thickened radiation shielding walls, which also requires huge capital investment and may take up more space.

[0006] Therefore, how to reduce the construction cost of Flash radiotherapy rooms while ensuring radiation safety is an urgent problem to be solved. Summary of the invention

[0007] Based on the above problems, the present application provides a Flash beam dose control method and related equipment, which can achieve precise control of the Flash beam output dose rate by accurately controlling the number of pulse cycles of the output beam charge and the pulse width of the ion source voltage; there is no need to add an additional shielding function to the particle accelerator room, so that the Flash dose of the particle accelerator can be debugged in a conventional particle accelerator room.

[0008] In a first aspect, the present application provides a proton beam dose control method, the method comprising:

[0009] Obtain proton beam output dose requirements;

[0010] Through the Flash debugging mode, the number of pulse cycles of the output beam charge is controlled within a preset time; and / or,

[0011] The pulse width of the ion source voltage is controlled through the pulse width mapping curve to achieve control of the proton beam output dose rate.

[0012] Preferably, controlling the number of pulse cycles of the output beam charge within a preset time includes:

[0013] According to the requirements of proton beam output dose, multiple duty cycles are preset;

[0014] The duty cycle is executed by the radio frequency control module to control the output power of the radio frequency amplifier in each pulse cycle, thereby achieving control of the proton beam output dose rate, and the radio frequency control module includes the FPGA counting module.

[0015] Preferably, the method further comprises:

[0016] If the duty cycle is greater than the first preset threshold and less than or equal to the second preset threshold; the pulse width of the ion source voltage is controlled to be within the first preset range;

[0017] If the duty cycle is greater than the second preset threshold, the pulse width of the ion source voltage is controlled to be within a second preset range.

[0018] Preferably, the method further comprises:

[0019] Get the output charge corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1;

[0020] Taking the ratio of the maximum safe output charge to the output charge as a first ratio, wherein the first preset threshold is less than or equal to the first ratio;

[0021] Obtaining a relationship between the duty cycle and the first ratio;

[0022] The range of the ion source voltage pulse width is determined according to the relationship between the duty cycle and the first ratio.

[0023] Preferably, controlling the pulse width of the ion source voltage by means of a pulse width mapping curve comprises:

[0024] Through the pulse width mapping curve, the ion source voltage pulse width corresponding to different charge amounts is obtained;

[0025] By controlling the ion source voltage pulse width, the output charge amount is controlled, thereby achieving control of the output dose rate.

[0026] Preferably, the method for acquiring the pulse width mapping curve includes:

[0027] Under a preset duty cycle, multiple charge amounts are obtained, and a preset pulse width mapping curve is obtained by calibrating the slope and calculating the difference; wherein each charge amount is an average value of the charge amounts obtained through multiple pulses;

[0028] The preset pulse width mapping curve is debugged by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve;

[0029] The output is verified by crossing the duty cycle and pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification results.

[0030] Preferably, the method of debugging a preset pulse width mapping curve by using ion source equipment parameters and radio frequency equipment parameters to obtain a debugged pulse width mapping curve comprises:

[0031] Set multiple duty cycles, each duty cycle corresponds to a pulse width, and test the output charge, where the product of each duty cycle and the corresponding pulse width is a constant value;

[0032] Repeat the test for multiple times, and if the difference in the output charge amount during the preset time is within the preset difference threshold range, the adjusted pulse width mapping curve is determined as the final adjusted pulse width mapping curve.

[0033] Preferably, the output verification is performed by crossing the duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, including:

[0034] Extracting pulse widths of different ion source voltages and corresponding duty ratios from a preset pulse width curve as first duty ratios, and recording corresponding output charge amounts as first output charge amounts;

[0035] The extracted pulse width is set as the first pulse width, and the ratio of the first pulse width to the maximum pulse width is obtained as the second ratio;

[0036] Let the first duty cycle be the ratio of the first verification pulse width to the maximum pulse width, obtain the first verification pulse width, let the second ratio be the second duty cycle corresponding to the first verification pulse width, and obtain the second output charge amount;

[0037] Comparing whether the difference between the first output charge amount and the second output charge amount is within a preset range; if not, performing curve optimization;

[0038] Through multiple cross-validation results, iterative optimization is performed.

[0039] In a second aspect, the present application provides a proton beam dose control device, the device comprising:

[0040] A demand acquisition module is used to obtain the proton beam output dose demand;

[0041] A Flash debugging module, used to control the number of pulse cycles of the output beam charge within a preset time through a Flash debugging mode; and / or,

[0042] The pulse width of the ion source voltage is controlled through the pulse width mapping curve to achieve control of the proton beam output dose rate.

[0043] In a third aspect, the present application provides a particle accelerator, the particle accelerator comprising:

[0044] An ion source system, a high frequency system and any proton beam dose control device described in the present application;

[0045] The ion source output dose of the ion source system and / or the high-frequency system is controlled by the control device.

[0046] In a fourth aspect, the present application also provides a particle therapy system, which includes the aforementioned particle accelerator for providing a Flash beam.

[0047] In a fifth aspect, the present application further provides a medical system, the system comprising:

[0048] Service debugging mode and clinical operation mode;

[0049] The service debugging mode includes a Flash debugging mode;

[0050] The Flash debugging mode realizes beam dose control through any method described in this application.

[0051] In a sixth aspect, the present application provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any method described in the present application or the functions of the device described in the present application when executing the computer program.

[0052] In a seventh aspect, the present application provides a computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions, the computer executes the steps of any method described in the present application.

[0053] Compared with the prior art, the beneficial effects of the present invention include at least: solving the problem of ultra-high dose rate of the equipment during Flash debugging by using a dose control method that cooperates with existing accelerator software and hardware systems; by accurately controlling the number of pulse cycles of the output beam charge and the pulse width of the ion source voltage, accurate control of the proton beam output dose rate can be achieved without additionally adding a shielding function to the proton machine room, making it possible to debug the Flash dose of the proton therapy equipment in a conventional proton machine room, thereby eliminating the economic cost caused by the additional huge shielding wall; not only can dose rate control be achieved by controlling the number of pulse cycles, but the pulse width of the ion source voltage can also be directly controlled by a pulse width mapping curve; this flexibility enables the method to adapt to different application scenarios and requirements, and has a wide range of applicability; through iterative optimization of the pulse width mapping curve, the control accuracy and efficiency can be further improved, and Flash dose debugging is conducive to Flash radiotherapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a schematic diagram of a proton beam dose control method according to an embodiment of the present invention;

[0055] Figure 2 is a schematic diagram of duty cycle control logic of a proton beam dose control method according to an embodiment of the present invention;

[0056] Figure 3 is a schematic diagram of the accelerator timing cycle according to an embodiment of the present invention;

[0057] Figure 4 1 is a pulse width control logic diagram of a proton beam dose control method according to an embodiment of the present invention;

[0058] Figure 5 is a pulse width mapping curve schematic diagram of an embodiment of the present invention;

[0059] Figure 6 is a schematic diagram of a particle accelerator according to an embodiment of the present invention;

[0060] Figure 7 is a schematic flow chart of a proton beam dose control method according to an embodiment of the present invention;

[0061] Figure 8 is a schematic diagram of a medical system according to an embodiment of the present invention;

[0062] Fig. 9 is a schematic diagram of a medical system debugging process according to an embodiment of the present invention;

[0063] Fig.10 This is a schematic diagram of the load shielding design of a common proton accelerator room. DETAILED DESCRIPTION

[0064] The exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0065] Since the large Flash beam releases a very large particle dose in a very short time, high requirements are placed on the radiation shielding wall. In other words, the site for Flash radiotherapy must have a strong enough radiation shielding capability, which requires the radiation shielding wall to be thick enough, so that the wall occupies a large area, requires a large amount of capital investment, and requires more stringent design specifications on the basis of the existing proton room design, and the requirements for environmental impact assessment will also increase accordingly. The particles can be protons, heavy ions or electrons.

[0066] Taking the proton therapy system debugging room as an example, according to the radiation protection standards, the external dose rate control level of the shielding body is shown in Table 1:

[0067] Table 1:

[0068]

[0069] Among them, the occupancy factor refers to the average time that the most exposed person stays in the area during the radiation source beam time. The dose rate refers to the radiation energy ingested per unit time, usually measured in millisieverts or microsieverts. It is an important safety indicator used to measure the impact of radiation on human health.

[0070] The present application provides a Flash beam dose control method, which can be a proton beam dose control method or a heavy ion beam dose control method. The method uses a dose control method that cooperates with existing accelerator software and hardware systems to cope with the radiation control requirements caused by ultra-high dose rates during Flash debugging or treatment, without adding additional shielding functions to the particle accelerator room, so that Flash dose debugging can be made possible in a conventional particle accelerator room; the load shielding design of an ordinary proton accelerator room refers to the attached Fig.10 .

[0071] Two control modes are added to the hospital's system service (Service) debugging mode and clinical (Clinical) operation mode, namely Flash mode and conventional mode. In the clinical operation mode, Flash dose rate control is achieved through Flash mode debugging. Before debugging and clearing the radiation interlocking system, selection buttons for conventional mode and Flash mode are added. The whole system parameter combination of conventional mode will only take effect when the conventional mode is selected, and the whole system parameter combination of Flash mode will only take effect when the Flash mode is selected. This radiation interlocking control mode can ensure the safety of the system radiation dose. In the conventional mode, there is no way to produce Flash beams. Only in the Flash mode will the metering control system configuration in the Flash mode be displayed. The service debugging mode includes debugging and maintenance modes, and the clinical operation mode is the mode used when treating patients.

[0072] The proton therapy equipment is installed in the hospital area. When performing Flash proton debugging or treatment, the dose rate output by the machine should be effectively measured and controlled on the first to third floors of the ordinary proton accelerator room. The machine can be a particle accelerator.

[0073] Some embodiments of the present application provide a proton beam dose control method, the method comprising:

[0074] Obtain proton beam output dose requirements;

[0075] Through the Flash debugging mode, the number of pulse cycles of the output beam charge is controlled within a preset time; and / or,

[0076] The pulse width of the ion source voltage is controlled through the pulse width mapping curve to achieve the control of the proton beam output dose rate, wherein the pulse width mapping curve is a corresponding relationship curve between the pulse width and the charge (PC). In this application, the pulse width (Pulse width, PW) and the pulse width mapping curve are expressed as PWC curves; the pulse width is adjustable in the range of 0-30uS.

[0077] See attached Figure 7 In some embodiments, the pulse width output range is obtained by adjusting the duty cycle, and the pulse width is adjusted through a pulse width mapping curve. The two methods are used in combination to achieve output dose control.

[0078] The working principle of the above technical solution is: if you want to reduce the dose rate in Flash mode, there are the following implementation forms. The first method is that within a certain time T (T>t), the accelerator pulse period is t, and there is no beam output in some pulse periods. The second method is that each pulse has a beam output, but through the pulse width mapping curve, the charge amount of each pulse is reduced, that is, the pulse width of the ion source voltage is reduced. Both can also be performed at the same time, and the number of pulse periods of the output beam within the preset time period, that is, the duty cycle and the pulse width of each pulse are controlled, thereby realizing the control of the proton beam output dose rate.

[0079] The effects of the above technical solution are: by controlling the number of pulse cycles and the pulse width of the ion source voltage (i.e., the output charge), the proton beam output dose rate can be precisely controlled; it can ensure that the treatment area obtains the predetermined dose while reducing the irradiation of healthy tissues; it provides a variety of ways to reduce the dose rate, including adjusting the pulse cycle and pulse width, so that the operator can flexibly adjust the dose rate according to the specific conditions and treatment needs of the patient; the use of the pulse width mapping curve ensures the correspondence between the ion source voltage pulse width and the charge amount, thereby ensuring the accuracy of dose control; in addition, the separate selection mechanism of Flash mode and conventional mode ensures that the high dose rate output is enabled only in Flash mode, further reducing the risk of misoperation. There is no need to add additional shielding function to the proton machine room, which reduces the equipment cost; at the same time, the existing accelerator hardware and software system is used to achieve dose control, which improves the utilization rate and economic benefits of the equipment; by adding Flash mode and conventional mode selection buttons in the hospital's system service debugging mode and clinical operation mode, the operation process is simplified, and the operator can easily switch between the two modes and adjust and control the dose rate as needed.

[0080] In some embodiments, controlling the number of pulse cycles of the output beam charge within a preset time includes:

[0081] According to the requirements of proton beam output dose, multiple duty cycles are preset;

[0082] The duty cycle is executed by a radio frequency control module to control the output power of the radio frequency amplifier in each pulse cycle, thereby achieving control of the proton beam output dose rate, wherein the radio frequency control module includes an FPGA counting module;

[0083] The duty cycle control logic diagram is shown in the attached Figure 2 .

[0084] The working principle and effect of the above technical solution are as follows: in Flash mode, if you want to reduce the dose rate, the first way is to have a pulse period of t within a certain time T (T>t), and there is no beam output in some pulse periods. For the convenience of calculation, T can be selected as an integer multiple of t. The unit of t described in this application is in the order of ms. The total time T is divided into T1 with beam output and T2 without beam output (T1, T2≤T), where: T1+T2=T; T1 and T2 are integer multiples of t respectively; the boundary conditions of the two T1 and T2 are: when T1=T and T2=0, the output dose rate is the maximum dose rate D1, and when T2=T, the output dose rate is 0. The dose rate calculation formula for other conditions is: D=T1 / T×D1.

[0085] Refer to the attached Figure 3 , schematic diagram of accelerator timing cycle, for example: if there are 5 accelerator pulse cycles t in the total time T, that is, T=5t, and T1=t, T2=4t, there is only one time t (i.e. one pulse cycle) with beam output, and the pulse width is the maximum constant, then in the total time T, the dose rate is D=1 / 5×D1, that is, the output dose rate is 1 / 5 of the maximum dose rate. The proportion of the pulse period of different output beams to the total pulse period, i.e., the duty cycle (BRD is used instead in this embodiment), can be set, wherein the duty cycle range can be 1 / 100-1 / 2, for example, the duty cycle is a proportional coefficient of 1 / 2, 1 / 5, 1 / 10, 1 / 20, 1 / 50, 1 / 100, under the same pulse width, the dose rate will also become a strictly corresponding 1 / 2, 1 / 5, 1 / 10, 1 / 20, 1 / 50, 1 / 100, the RF amplifier is controlled in the RF control module, counting is performed by the FPGA-based control module, and the duty cycle is executed by controlling the RF power output; the problem of high accelerator output dose rate in Flash mode can be effectively controlled by combining software and hardware, so as to meet the Flash debugging of the proton therapy equipment at the hospital site without performing Flash environmental impact assessment and changing the thickness of the infrastructure wall.

[0086] In some embodiments, the method further comprises:

[0087] If the duty cycle is greater than the first preset threshold and less than or equal to the second preset threshold; the pulse width of the ion source voltage is controlled to be within the first preset range;

[0088] If the duty cycle is greater than the second preset threshold, the pulse width of the ion source voltage is controlled to be within a second preset range.

[0089] In some embodiments, the method further comprises:

[0090] Get the output charge corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1;

[0091] Taking the ratio of the maximum safe output charge to the output charge as a first ratio, wherein the first preset threshold is less than or equal to the first ratio;

[0092] Obtaining a relationship between the duty cycle and the first ratio;

[0093] The range of the ion source voltage pulse width is determined according to the relationship between the duty cycle and the first ratio.

[0094] The working principle of the above technical solution is as follows: the duty cycle (BRD) is defined as the ratio of the number of pulse cycles with beam output to the total number of pulse cycles; by adjusting the BRD, the total dose rate of the proton beam can be controlled; the pulse width of the ion source voltage determines the charge of the proton beam in each pulse cycle; the longer the pulse width, the greater the charge, and thus the greater the contributed dose; in order to establish a correlation between BRD and the pulse width of the ion source voltage, two thresholds (a first preset threshold and a second preset threshold) and two pulse width ranges (a first preset range and a second preset range) are set; when the BRD is less than the first preset threshold, even with the maximum pulse width, the beam dose rate can still be within a safe range; when the BRD is greater than the first preset threshold and less than or equal to the second preset threshold, the pulse width of the ion source voltage is controlled within the first preset range; when the BRD is greater than the second preset threshold, the pulse width is limited to the second preset range to ensure that the beam dose rate is within a safe range, and multiple thresholds can be set, and here only two thresholds are used as examples.

[0095] Among them, the output charge corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1 (that is, there is beam output in all pulse periods) is obtained, which represents the maximum dose that can be generated by the ion source voltage under the maximum pulse width, and the maximum safe output charge is determined, which is usually the upper limit of the safe dose; the ratio of the maximum safe output charge to the output charge corresponding to the maximum pulse width is taken as the first ratio; this ratio represents the proportional relationship between the safe dose and the maximum dose; if the duty cycle is less than the first ratio, even if the maximum pulse width is used, the beam dose rate can still be within the safe range; if the duty cycle is greater than the first ratio, then according to the safety dose requirement and the value of the duty cycle, the pulse width of the ion source voltage is proportionally reduced, and the pulse width threshold is set to ensure that the beam dose rate is within the safe range.

[0096] The effects of the above technical solution are: by combining the adjustment of the duty cycle (BRD) and the control of the ion source voltage pulse width, the proton beam output dose rate is precisely controlled; this combined control strategy allows the dose rate to be flexibly adjusted according to the treatment needs to meet the treatment needs of different patients; multiple thresholds and corresponding pulse width ranges can be set to ensure that the pulse width of the ion source voltage can be controlled within a suitable range under different duty cycles, thereby avoiding possible damage to the patient due to excessive dose rate, and by calculating the ratio of the maximum safe output charge to the output charge corresponding to the maximum pulse width as the basis for duty cycle adjustment, the safety of the treatment process is further ensured, and the functions of the existing accelerator hardware and software systems are used to achieve dose control through a combination of software control and hardware adjustment, without the need to add expensive equipment or perform complex modifications, thereby reducing equipment costs. At the same time, due to the use of a combination of hardware and software solutions based on modern control technologies such as FPGA, the system maintenance is simpler and more convenient, reducing maintenance costs.

[0097] In summary, this technical solution improves the safety and flexibility of treatment and reduces equipment and maintenance costs by precisely controlling the dose rate of the proton beam.

[0098] In some embodiments, controlling the pulse width of the ion source voltage by using a pulse width mapping curve includes:

[0099] Through the pulse width mapping curve, the ion source voltage pulse width corresponding to different charges is obtained; among them, the pulse width and charge curve (pulse width mapping curve) schematic diagram refers to Figure 5 ;

[0100] Control the ion source voltage pulse width and control the output charge amount, thereby achieving control of the output dose rate. The working principle of the above technical solution is: if each pulse has a charge output, or the set value of the duty cycle is greater than the first preset threshold, in order to achieve dose control, it is necessary to control the cathode voltage pulse width of the ion source hydrogen ionization. When there is a cathode voltage, hydrogen will be ionized into a plasma mainly composed of hydrogen ions. When there is no cathode voltage, hydrogen is not ionized. Different ion source cathode voltage pulse widths are calibrated to correspond to different charge amounts. The calibrated correspondence between the ion source cathode voltage pulse width and the charge amount is debugged through a specific beam spot diagram. The beam spot diagram includes beam spot information, digital beam spot position coordinates, energy and charge amount information, and then it is stored in the form of an Xml file. Use this stored file for precise dose control. For example, if you want each pulse to output a charge of 4.5pc, you only need to set the ion source pulse width to 2.5us data. The ion source pulse and charge amount control logic diagram is shown in the attached figure. Figure 4 .

[0101] The effects of the above technical solution are as follows: by calibrating and storing the corresponding relationship between the pulse width of the cathode voltage of the ion source and the amount of charge, the system can accurately control the amount of charge output by each pulse, thereby ensuring the accuracy of the output dose rate; accurately controlling the dose rate can ensure the safety of treatment; by pre-calibrating and storing the corresponding relationship between the pulse width and the amount of charge, accurate dose control can be achieved through simple settings without complex calculations and debugging, which simplifies the operation process, reduces the difficulty of operation, and improves work efficiency; the corresponding relationship between the pulse width and the amount of charge is stored in the form of an XML file, making the system easy to expand and maintain; when the corresponding relationship needs to be updated or modified, it is only necessary to modify the corresponding XML file without large-scale changes to the entire system, reducing maintenance costs and improving the flexibility and scalability of the system. Through accurate dose control and simplified operation procedures, the possibility of human error is reduced, and the reliability and stability of the system are improved. This is crucial to ensure the safety and effectiveness of the radiotherapy process.

[0102] In some embodiments, the method for obtaining the pulse width mapping curve includes:

[0103] Under a preset duty cycle, multiple charge amounts are obtained, and a preset pulse width mapping curve is obtained by calibrating the slope and calculating the difference; wherein each charge amount is an average value of the charge amounts obtained through multiple pulses;

[0104] The preset pulse width mapping curve is debugged by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve;

[0105] The output is verified by crossing the duty cycle and pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification results.

[0106] The working principle of the above technical solution is as follows: since the duty cycle control method is to count through the FPGA-based control module, the duty cycle is executed by controlling the RF power output; the ion source cathode voltage pulse mode is to control the number of plasma charges for hydrogen ionization in the future by controlling the opening of the ion source cathode voltage. The former has a strictly linear multiple relationship, and the latter usually does not become a strictly linear proportional relationship due to the complexity of plasma ionization and the response of uS-level control. At this time, PWC debugging is required. After multiple iterations of adjusting system parameters such as ion source frequency and high-frequency frequency, a set of strict correspondence between ion source pulse width and charge output is formed. The characteristics of this correspondence are continuity and smoothness; due to the influence of many equipment factors such as high-voltage power supply, control module, ion source frequency, RF frequency and timing, more complex debugging and calibration are required. Starting from the requirements of dose control, the PWC (Pulse width Curve) curve must be monotonous and smooth, and strict debugging tests and stability tests are required. The specific methods are as follows:

[0107] Under a preset duty cycle, multiple pulses are generated by an ion source or related equipment, where the preset duty cycle can be a duty cycle that is less than a certain value of a first preset threshold value; under the preset duty cycle, a preset slope of charge / pulse width is used as the initial default charge and pulse width mapping correspondence, where the preset slope of charge / pulse width can be charge / pulse width=2, to obtain multiple charge quantities, each charge quantity information is obtained by taking an average value by making multiple (for example: 100) identical pulses, and using the mean charge quantity and the corresponding pulse width, a preset pulse width mapping curve is drawn or fitted by calibrating the slope (i.e., the slope of the charge quantity changing with the pulse width) and possible difference calculations.

[0108] The working parameters of the ion source equipment and the radio frequency equipment (for example, the iterative debugging of the parameters such as the accelerator ion source voltage opening frequency, the ion source voltage value, the ion source hydrogen flow rate, the radio frequency opening frequency and the radio frequency power output) will directly affect the generation of pulses and charges. According to the actual parameters of these devices, the preset pulse width mapping curve is debugged to more accurately reflect the actual working conditions. The debugging process may include adjusting the slope, offset, curve shape, etc. to ensure that the pulse width mapping curve is more consistent with the experimental data; selecting different duty cycle and pulse width ratio combinations, generating corresponding pulses through the ion source equipment, and measuring the generated charge; comparing these measured values ​​with the values ​​predicted by the pulse width mapping curve to verify the accuracy of the curve. If there is a significant difference, it means that the pulse width mapping curve needs to be further optimized. According to the results of the output verification, the pulse width mapping curve is iteratively optimized; the optimization method may include adjusting the calibration slope, modifying the difference calculation method, using a more complex fitting algorithm, etc.; repeating the output verification of the cross duty cycle and pulse width ratio until the error between the predicted value and the actual measured value of the pulse width mapping curve reaches an acceptable range.

[0109] The effects of the above technical solution are: by obtaining multiple charge quantities under a preset duty cycle and calculating the average, the error caused by a single measurement is reduced and the accuracy of the charge quantity data is improved; the preset pulse width mapping curve obtained by using the calibration slope and difference calculation provides a relatively accurate initial basis for subsequent debugging and optimization; considering the influence of the ion source equipment and radio frequency equipment parameters on the charge quantity output, by debugging the preset pulse width mapping curve, it can be made more suitable for the working conditions of the actual equipment, thereby improving the practicality and accuracy of the pulse width mapping curve.

[0110] In some embodiments, the preset pulse width mapping curve is debugged by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve; including:

[0111] Set multiple duty cycles, each duty cycle corresponds to a pulse width, and test the output charge, where the product of each duty cycle and the corresponding pulse width is a constant value; as shown in Table 2;

[0112] Repeat the test for multiple times, and if the difference in the output charge amount during the preset time is within the preset difference threshold range, the adjusted pulse width mapping curve is determined as the final adjusted pulse width mapping curve.

[0113] The working principle and effect of the above technical solution are as follows: the duty cycle is the ratio of the pulse width to the pulse period, which determines the proportion of the pulse "on" time to the total time. During the debugging process, multiple groups of different duty cycles are set, and each group of duty cycles corresponds to a specific set of pulse widths. It is important that the product of each group of duty cycles and the corresponding pulse width is a constant value, which ensures that the total energy of the pulse (or the total accumulation of charge) remains consistent under different duty cycles, so that the impact of different duty cycles on the charge output can be fairly compared. For each set of duty cycles and corresponding pulse widths, a pulse is generated by the ion source device, and the charge output is measured. This charge represents the amount of charge that the ion source device can generate under a given duty cycle and pulse width. In order to ensure the accuracy and reliability of the test results, each group of duty cycle and pulse width combination will be tested repeatedly.

[0114] Within a preset time (such as a few hours or three times a day), the test is continuously carried out for a period of time (such as a week), and the charge is output to observe the differences between these charge amounts; if these differences are within the preset difference threshold range (that is, the change in charge amount is within an acceptable range), the test results are considered stable and reliable; based on the results of multiple tests, the output of charge amount under different duty cycle and pulse width combinations can be observed; by analyzing these data, the initial preset pulse width mapping curve can be debugged and optimized to make it more accurately reflect the working characteristics of the ion source equipment under different conditions. Once the test results are stable and meet the preset difference threshold requirements, the debugged pulse width mapping curve can be determined as the final pulse width mapping curve.

[0115] For example: Test five different BRDs and corresponding ion source pulse width configurations for charge output from the table below, and use multiple measurements to take the average value. If the difference between the five sets of data is within a very small range (e.g. 10%), the verification is passed.

[0116] Table 2:

[0117]

[0118] In some embodiments, the output verification is performed by crossing the duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, including:

[0119] Extracting pulse widths of different ion source voltages and corresponding duty ratios from a preset pulse width curve as first duty ratios, and recording corresponding output charge amounts as first output charge amounts;

[0120] The extracted pulse width is set as the first pulse width, and the ratio of the first pulse width to the maximum pulse width is obtained as the second ratio;

[0121] Let the first duty cycle be the ratio of the first verification pulse width to the maximum pulse width, obtain the first verification pulse width, let the second ratio be the second duty cycle corresponding to the first verification pulse width, and obtain the second output charge amount;

[0122] Comparing whether the difference between the first output charge amount and the second output charge amount is within a preset range; if not, performing curve optimization;

[0123] Through multiple cross-validation results, iterative optimization is performed.

[0124] The working principle of the above technical solution is: in the process of iterative optimization of the pulse width mapping curve, an effective method is to perform output verification by crossing the duty cycle and pulse width ratio. The core idea of ​​this method is to evaluate the accuracy of the current pulse width mapping curve by comparing the output charge obtained under different duty cycle and pulse width settings, and perform necessary optimization based on the verification results.

[0125] From the preset pulse width mapping curve, select the pulse width values ​​under different ion source voltages and the corresponding duty cycle as the first duty cycle. These pulse widths and duty cycles represent the working settings under different conditions; record the charge output by the ion source device under these settings as the first output charge. Compare the extracted pulse width (i.e., the first pulse width) with the maximum pulse width, calculate their ratio, and obtain the second ratio. This ratio reflects the degree of scaling of the current pulse width relative to the maximum pulse width.

[0126] Let the first duty cycle (i.e. the duty cycle originally set) be equal to the ratio of the first verification pulse width (a hypothetical pulse width value) to the maximum pulse width; based on this assumption, the first verification pulse width can be calculated; the second ratio calculated in the second step is used as the second duty cycle corresponding to the first verification pulse width; then, the second duty cycle and the first verification pulse width are set on the ion source device, and the output charge at this time is recorded as the second output charge. Compare the difference between the first output charge and the second output charge; if the difference exceeds the preset range (i.e. the inconsistency between the two is too large), it means that the current pulse width mapping curve may not be accurate enough and needs to be optimized. If the verification result shows that the difference exceeds the preset range, the pulse width mapping curve needs to be optimized; the optimization method can be to adjust certain points on the curve or smooth the entire curve to reduce this inconsistency.

[0127] In order to ensure that the optimized pulse width mapping curve can work accurately under various conditions, multiple cross-validations are required. This includes selecting different combinations of ion source voltage, pulse width and duty cycle, and repeating the above validation process. Based on the results of each validation, the pulse width mapping curve is iteratively optimized until a consistent and accurate output charge can be obtained under various conditions.

[0128] The effect of the above technical solution is: the cross-validation method can comprehensively test the accuracy of the pulse width mapping curve under different combinations of ion source voltage, pulse width and duty cycle. This comprehensive verification ensures that the pulse width mapping curve can provide accurate output charge prediction under various experimental and production conditions; the iterative optimization process can gradually adjust the pulse width mapping curve according to the difference between the actual output charge and the expected value, so that it is more suitable for the actual working performance of the ion source equipment. This adaptability enables the pulse width mapping curve to provide more reliable support in practical applications; multiple cross-validations and iterative optimizations can ensure the stability and consistency of the pulse width mapping curve. Through repeated verification and adjustment, potential errors and deviations can be eliminated and the reliability of the pulse width mapping curve can be improved.

[0129] The present application provides a proton beam dose control device, the device comprising:

[0130] A demand acquisition module is used to obtain the proton beam output dose demand;

[0131] A debugging module, used to control the number of pulse cycles of the output beam charge within a preset time through a Flash debugging mode; and / or,

[0132] The pulse width of the ion source voltage is controlled through the pulse width mapping curve to achieve control of the proton beam output dose rate.

[0133] In some embodiments, the debugging module includes a first debugging unit and a second debugging unit, wherein the first debugging unit is used to control the number of pulse cycles of the output beam charge within a preset time; the second debugging unit is used to control the pulse width of the ion source voltage through a pulse width mapping curve to achieve control of the proton beam output dose rate;

[0134] The first debugging unit comprises:

[0135] A preset duty cycle unit is used to preset multiple duty cycles according to the requirements of the proton beam output dose;

[0136] The first control unit is used to execute the duty cycle through the radio frequency control module to control the output power of the radio frequency amplifier in each pulse period, thereby realizing the control of the proton beam output dose rate, and the radio frequency control module includes an FPGA counting module.

[0137] In some embodiments, the first control unit comprises:

[0138] A first control subunit, configured to control the pulse width of the ion source voltage to be within a first preset range if the duty cycle is greater than a first preset threshold and less than or equal to a second preset threshold;

[0139] The second control subunit is used to control the pulse width of the ion source voltage to be within a second preset range if the duty cycle is greater than a second preset threshold.

[0140] In some implementations, the first debugging unit further includes:

[0141] A first acquisition unit is used to acquire the output charge amount corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1;

[0142] A first threshold setting unit, configured to use a ratio of a maximum safe output charge to the output charge as a first ratio, wherein the first preset threshold is less than or equal to the first ratio;

[0143] The range determination unit is used to obtain the relationship between the duty cycle and the first ratio; and determine the range of the ion source voltage pulse width according to the relationship between the duty cycle and the first ratio.

[0144] In some embodiments, the second debugging unit includes:

[0145] The charge acquisition unit obtains different charge quantities corresponding to the ion source voltage pulse width through the pulse width mapping curve;

[0146] The second control unit is used to control the ion source voltage pulse width and the output charge amount, thereby achieving output dose rate control.

[0147] In some embodiments, in the second debugging unit, the method for acquiring the pulse width mapping curve includes:

[0148] Under a preset duty cycle, multiple charge amounts are obtained, and a preset pulse width mapping curve is obtained by calibrating the slope and calculating the difference; wherein each charge amount is an average value of the charge amounts obtained through multiple pulses;

[0149] The preset pulse width mapping curve is debugged by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve;

[0150] The output is verified by crossing the duty cycle and pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification results.

[0151] In some embodiments, in the second debugging unit, debugging the preset pulse width mapping curve through the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve includes:

[0152] Set multiple duty cycles, each duty cycle corresponds to a pulse width, and test the output charge, where the product of each duty cycle and the corresponding pulse width is a constant value;

[0153] Repeat the test for multiple times, and if the difference in the output charge amount during the preset time is within the preset difference threshold range, the adjusted pulse width mapping curve is determined as the final adjusted pulse width mapping curve.

[0154] In some embodiments, in the second debugging unit, the output verification is performed by crossing the duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, including:

[0155] Extracting pulse widths of different ion source voltages and corresponding duty ratios from a preset pulse width curve as first duty ratios, and recording corresponding output charge amounts as first output charge amounts;

[0156] The extracted pulse width is set as the first pulse width, and the ratio of the first pulse width to the maximum pulse width is obtained as the second ratio;

[0157] Let the first duty cycle be the ratio of the first verification pulse width to the maximum pulse width, obtain the first verification pulse width, let the second ratio be the second duty cycle corresponding to the first verification pulse width, and obtain the second output charge amount;

[0158] Comparing whether the difference between the first output charge amount and the second output charge amount is within a preset range; if not, performing curve optimization;

[0159] Through multiple cross-validation results, iterative optimization is performed.

[0160] The working principle and effect of the above technical solution are the same as the corresponding principles and effects in the proton beam dose control method in the embodiment of the present application, and will not be elaborated here.

[0161] See attached Figure 6 : The embodiment of the present application also provides a particle accelerator, the particle accelerator comprising:

[0162] An ion source system, a high frequency system and a proton beam dose control device as described in any one of the embodiments;

[0163] The ion source output dose of the ion source system and / or the high-frequency system is controlled by the control device.

[0164] Among them, the accelerator may include five major subsystems, specifically: an ion source system for providing particles, a vacuum system for providing the environment required for particle acceleration, a magnet system for guiding the direction of particle movement, a high-frequency system for providing the energy required for particle acceleration, an extraction system for extracting particles from the inside of the accelerator, and a supporting system for power supply, cooling, etc. for the accelerator. If you want to control the beam from extraction to beam stop in a very short period of time, in theory, you can control the equipment of any of the six systems in the figure to achieve it, but considering the operability and convenience of stopping and restoring the beam, as well as the time accuracy of control, especially for the ultra-high dose rate scenario of Flash in a short period of time, then it is preferred to control the ion source subsystem and the high-frequency subsystem to achieve it. The accelerator may be a cyclotron accelerator; the particles may be protons, heavy ions or electrons, and the particle accelerator may be a proton accelerator.

[0165] An embodiment of the present application also provides a particle therapy system, which includes the aforementioned particle accelerator for providing a Flash beam; the particle therapy system may be a proton therapy system, which includes a proton therapy device, and the proton therapy device includes the aforementioned accelerator.

[0166] See attached Figure 8 : This embodiment also provides a medical system, the system comprising:

[0167] Service debugging mode and clinical operation mode;

[0168] The service debugging mode includes a Flash debugging mode;

[0169] The Flash debugging mode realizes beam dose control through any method described in the embodiments of the present application.

[0170] Reference Fig. 9 : The radiation interlocking system adds selection buttons for normal mode and Flash mode before debugging and clearing the field. The whole system parameter combination of normal mode will only take effect when normal mode is selected, and the whole system parameter combination of Flash mode will only take effect when Flash mode is selected. This radiation interlocking control mode can ensure the safety of the system radiation dose. There is no way to produce Flash proton beam in normal mode. Only in Flash mode can the metering control system configuration in Flash mode be displayed, and Flash dose control is performed by adjusting BRD and PW.

[0171] An embodiment of the present application also provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of any method described in the embodiments of the present application or the functions of the device described in the embodiments of the present application are implemented.

[0172] The embodiments of the present application also provide a computer-readable storage medium, which is used to store a computer program. When the computer program is executed, the steps of the method in the embodiments of the present application are implemented. The specific implementation method is consistent with the implementation method and the technical effect achieved recorded in the above method embodiments, and some contents will not be repeated here.

[0173] In the present application, a readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it. A program product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0174] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, wherein readable program codes are carried. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium may also be any readable medium, which may send, propagate, or transmit a program for use by an instruction execution system, an apparatus, or a device or for use in combination with it. The program code contained on the readable storage medium may be transmitted with any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above. The program code for performing the operation of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and also conventional procedural programming languages ​​such as C language or similar programming languages. The program code may be executed entirely on a user computing device, partially on an associated device, as an independent software package, partially on a user computing device, partially on a remote computing device, or entirely on a remote computing device or server. Where a remote computing device is involved, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0175] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, substitute and modify the above embodiments within the scope of the invention without departing from the principles and purpose of the present invention. All such changes should fall within the scope of protection of the claims of the present invention.

Claims

1. A Flash beam dose control method, characterized in that: The method comprises: Obtain Flash beam output dose requirements; Control the number of pulse cycles of the output beam charge within a preset time through the Flash debug mode; and, Through the pulse width mapping curve, the ion source voltage pulse width corresponding to different charge amounts is obtained; the pulse width of the ion source voltage is controlled to achieve the control of the Flash beam output dose rate; The step of controlling the number of pulse cycles of the output beam charge within a preset time includes: According to the requirements of Flash beam output dose, multiple duty cycles are preset; If the duty cycle is greater than the first preset threshold and less than or equal to the second preset threshold; the pulse width of the ion source voltage is controlled to be within the first preset range; If the duty cycle is greater than a second preset threshold, controlling the pulse width of the ion source voltage to be within a second preset range; The method for obtaining the pulse width mapping curve includes: Under a preset duty cycle, multiple charge amounts are obtained, and a preset pulse width mapping curve is obtained by calibrating the slope and calculating the difference; wherein each charge amount is an average value of the charge amounts obtained through multiple pulses; The preset pulse width mapping curve is debugged by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve; The output is verified by crossing the duty cycle and pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification results; The output verification is performed by crossing the duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, including: Extracting pulse widths of different ion source voltages and corresponding duty ratios from a preset pulse width curve as first duty ratios, and recording corresponding output charge amounts as first output charge amounts; The extracted pulse width is set as the first pulse width, and the ratio of the first pulse width to the maximum pulse width is obtained as the second ratio; Let the first duty cycle be the ratio of the first verification pulse width to the maximum pulse width, obtain the first verification pulse width, let the second ratio be the second duty cycle corresponding to the first verification pulse width, and obtain the second output charge amount; Compare whether the difference between the first output charge amount and the second output charge amount is within a preset range; if not, perform curve optimization.

2. The control method according to claim 1, characterized in that: The step of controlling the number of pulse cycles of the output beam charge within a preset time further includes: The duty cycle is executed by the radio frequency control module to control the output power of the radio frequency amplifier in each pulse cycle, thereby realizing the control of the Flash beam output dose rate. The radio frequency control module includes an FPGA counting module.

3. The control method according to claim 1, characterized in that: The method further comprises: Obtain the output charge corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1; Taking the ratio of the maximum safe output charge to the output charge as a first ratio, wherein the first preset threshold is less than or equal to the first ratio; Obtaining a relationship between the duty cycle and the first ratio; The range of the ion source voltage pulse width is determined according to the relationship between the duty cycle and the first ratio.

4. The control method according to claim 1, characterized in that: The controlling the pulse width of the ion source voltage by the pulse width mapping curve comprises: Through the pulse width mapping curve, the ion source voltage pulse width corresponding to different charge amounts is obtained; By controlling the ion source voltage pulse width, the output charge amount is controlled, thereby achieving control of the output dose rate.

5. The control method according to claim 1, characterized in that: The method of debugging the preset pulse width mapping curve by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve comprises: Set multiple duty cycles, each duty cycle corresponds to a pulse width, and test the output charge, where the product of each duty cycle and the corresponding pulse width is a constant value; Repeat the test for multiple times, and if the difference in the output charge amount during the preset time is within the preset difference threshold range, the adjusted pulse width mapping curve is determined as the final adjusted pulse width mapping curve.

6. The control method according to claim 1, characterized in that: The output verification is performed by crossing the duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, including: Through multiple cross-validation results, iterative optimization is performed.

7. A Flash beam dose control device, characterized in that: The device comprises: The demand acquisition module is used to obtain the Flash beam output dose demand; A Flash debugging module, used to control the number of pulse cycles of the output beam charge within a preset time through a Flash debugging mode; and, Through the pulse width mapping curve, the pulse width of the ion source voltage is controlled to achieve the control of the Flash beam output dose rate; The step of controlling the number of pulse cycles of the output beam charge within a preset time includes: According to the requirements of Flash beam output dose, multiple duty cycles are preset; If the duty cycle is greater than the first preset threshold and less than or equal to the second preset threshold; the pulse width of the ion source voltage is controlled to be within the first preset range; If the duty cycle is greater than a second preset threshold, controlling the pulse width of the ion source voltage to be within a second preset range; The method for obtaining the pulse width mapping curve includes: Under a preset duty cycle, multiple charge amounts are obtained, and a preset pulse width mapping curve is obtained by calibrating the slope and calculating the difference; wherein each charge amount is an average value of the charge amounts obtained through multiple pulses; The preset pulse width mapping curve is debugged by using the ion source device parameters and the radio frequency device parameters to obtain the debugged pulse width mapping curve; The output is verified by crossing the duty cycle and pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification results; The output verification is performed by crossing the duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, including: Extracting pulse widths of different ion source voltages and corresponding duty ratios from a preset pulse width curve as first duty ratios, and recording corresponding output charge amounts as first output charge amounts; The extracted pulse width is set as the first pulse width, and the ratio of the first pulse width to the maximum pulse width is obtained as the second ratio; Let the first duty cycle be the ratio of the first verification pulse width to the maximum pulse width, obtain the first verification pulse width, let the second ratio be the second duty cycle corresponding to the first verification pulse width, and obtain the second output charge amount; Compare whether the difference between the first output charge amount and the second output charge amount is within a preset range; if not, perform curve optimization.

8. A particle accelerator, characterized in that: The particle accelerator comprises: An ion source system, a high frequency system, and a control device as claimed in claim 7; The ion source output dose of the ion source system and / or the high-frequency system is controlled by the control device.

9. A particle therapy system, characterized in that: The particle therapy system comprises the particle accelerator of claim 8.

10. A medical system, characterized in that: The system comprises: Service debugging mode and clinical operation mode; The service debugging mode includes a Flash debugging mode; The Flash debugging mode realizes beam dose control through any method described in claims 1-6.

11. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of any method described in claims 1 to 6 or implements the functions of the device described in claim 7 when executing the computer program.

12. A computer-readable storage medium, characterized in that: The storage medium stores computer instructions. When a computer reads the computer instructions, the computer executes the steps of the method according to any one of claims 1 to 6 or implements the functions of the device according to claim 7.

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