Flash beam dose control method and related device

Abstract

A Flash beam dose control method and a related device. The Flash beam dose control method comprises: obtaining a Flash beam output dose demand; controlling, by means of a Flash tuning mode, the number of pulse periods of output beam charges within a preset time; and / or controlling the pulse width of an ion source voltage by means of a pulse width mapping curve, so as to control a Flash beam output dose rate. By precisely controlling the number of pulse periods of output beam charges and the pulse width of the ion source voltage, the Flash beam output dose rate can be precisely controlled without requiring an additional shielding function for a proton therapy room, so that the dose of Flash can also be tuned in a conventional proton therapy room, thereby facilitating implementation of particle Flash radiotherapy.

Description

Flash beam dose control method and related device

[0001] The present application claims priority to the Chinese patent application No. 202410705776.7, filed on June 03, 2024, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of particle therapy, for example to a Flash beam dose control method and related device. BACKGROUND

[0003] 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 concentrate the energy of the radiation more effectively in the tumor target area that needs to be treated, significantly protect healthy tissues, and improve local tumor control rates, while greatly reducing the risk of radiation complications in normal organs and tissues.

[0004] 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 the release of a large dose of radiation through a Flash beam, i.e., a particle beam with an extremely high dose rate, in a very short time, the requirements for the radiation shielding wall are extremely high. In order to ensure that the radiation dose rate outside the machine room during treatment meets the safety standards, the radiation shielding wall needs to be thick enough to provide adequate protection, resulting in a larger footprint of the wall and increased investment in the construction of the machine room.

[0005] Taking a proton therapy system commissioning machine room as an example, according to the radiation protection standards, there are clear requirements for the dose rate control levels at different positions (such as outside the shielding wall around the machine room, outside the entrance protection door, outside the machine room roof and machine room floor). In order to meet these requirements, hospitals and / or enterprises must consider radiation shielding issues when designing and constructing the machine room.

[0006] In the application of Flash radiotherapy technology, in order to achieve the dose rate control level that meets the safety standards, there are two main solutions: one is to design a complex Flash radiation protection shielding device, which requires special materials and a large amount of research and development investment; the other is to use a thickened radiation shielding wall, which also requires a huge investment and may occupy more space.

[0007] Therefore, how to reduce the construction cost of the Flash radiotherapy machine room while ensuring radiation safety is a problem that needs to be solved at present. SUMMARY

[0008] Based on the above problems, the application provides a flash beam dose control method and related equipment, which can accurately control the flash beam output dose rate by accurately controlling the pulse period number of the output beam charge and the pulse width of the ion source voltage; without additional shielding function of the particle accelerator room, the flash dose of the particle accelerator can be debugged in the conventional particle accelerator room.

[0009] In a first aspect, the application provides a proton beam dose control method, which comprises:

[0010] obtaining a proton beam output dose requirement;

[0011] controlling the number of pulse periods of the output beam charge within a preset time through a flash debugging mode; and / or,

[0012] controlling the pulse width of the ion source voltage through a pulse width mapping curve to achieve control of the proton beam output dose rate.

[0013] In some possible implementation manners, the controlling of the number of pulse periods of the output beam charge within a preset time comprises:

[0014] presetting a plurality of duty cycles according to the requirement of the proton beam output dose;

[0015] controlling the output power of the radio frequency amplifier in each pulse period through a radio frequency control module to execute the duty cycle, thereby achieving control of the proton beam output dose rate, wherein the radio frequency control module comprises the FPGA counting module.

[0016] In some possible implementation manners, the method further comprises:

[0017] if the duty cycle is greater than a first preset threshold and less than or equal to a second preset threshold, then the pulse width of the ion source voltage is controlled to be within a first preset range;

[0018] if the duty cycle is greater than the second preset threshold, then the pulse width of the ion source voltage is controlled to be within a second preset range.

[0019] In some possible implementation manners, the method further comprises:

[0020] obtaining an output charge amount corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1;

[0021] taking the ratio of the maximum safe output charge amount to the output charge amount as a first ratio, and the first preset threshold is less than or equal to the first ratio;

[0022] obtaining the relationship between the duty cycle and the first ratio;

[0023] According to the relationship between the duty cycle and the first ratio, a range of the ion source voltage pulse width is determined.

[0024] In some possible implementation manners, the controlling the ion source voltage pulse width through the pulse width mapping curve comprises:

[0025] The ion source voltage pulse width is obtained through the pulse width mapping curve corresponding to different charge amounts.

[0026] The ion source voltage pulse width is controlled, the output charge amount is controlled, and thus the control of the output dose rate is realized.

[0027] In some possible implementation manners, the obtaining method of the pulse width mapping curve comprises:

[0028] Under a preset duty cycle, a plurality of charge amounts are obtained, a preset pulse width mapping curve is obtained through a calibration slope and a difference calculation, and each charge amount is an average of charge amounts obtained through a plurality of pulses.

[0029] The preset pulse width mapping curve is debugged through ion source device parameters and radio frequency device parameters, and a debugged pulse width mapping curve is obtained.

[0030] Output verification is performed through the cross duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to a verification result.

[0031] In some possible implementation manners, the preset pulse width mapping curve is debugged through the ion source device parameters and the radio frequency device parameters, and the debugged pulse width mapping curve is obtained, which comprises:

[0032] A plurality of groups of duty cycles are set, each group of duty cycles corresponds to a group of pulse widths, and an output charge amount is tested, wherein the product of each group of duty cycles and the corresponding pulse width is a constant value.

[0033] The test is repeated multiple times, the output charge amount difference is within a preset difference threshold range in a preset time, and the debugged pulse width mapping curve is determined as a final debugged pulse width mapping curve.

[0034] In some possible implementation manners, the output verification is performed through the cross duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result, which comprises:

[0035] The pulse widths of different ion source voltages and the corresponding duty cycles as the first duty cycles are extracted from the preset pulse width curve, and the corresponding output charge amounts are recorded as the first output charge amounts.

[0036] The extracted pulse widths are set as the first pulse widths, the ratio of the first pulse widths to the maximum pulse width is obtained as a second ratio.

[0037] Let the first duty cycle be the ratio of the first verification pulse width and 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, obtain the second output charge amount;

[0038] Compare the difference between the first output charge amount and the second output charge amount whether in the preset range; if not, the curve optimization is carried out;

[0039] Through multiple cross-validation results, iterative optimization is carried out.

[0040] In the second aspect, the present application provides a proton beam dose control device, the device comprises:

[0041] The demand acquisition module is used for acquiring the proton beam output dose demand;

[0042] The Flash debugging module is used for controlling the number of pulse periods of the output beam current within a preset time through the Flash debugging mode; and / or,

[0043] The pulse width of the ion source voltage is controlled through the pulse width mapping curve, and the control of the proton beam output dose rate is realized.

[0044] In the third aspect, the present application provides a particle accelerator, the particle accelerator comprises:

[0045] Ion source system, high frequency system and any of the proton beam dose control devices of the present application;

[0046] The ion source output dose of the ion source system and / or the high frequency system is controlled through the control device.

[0047] In the fourth aspect, the present application further provides a particle therapy system, the particle therapy system comprises the particle accelerator for providing the Flash beam.

[0048] In the fifth aspect, the present application further provides a medical system, the system comprises:

[0049] Service debugging mode and clinical operation mode;

[0050] The service debugging mode comprises a Flash debugging mode;

[0051] The Flash debugging mode realizes the beam dose control through any of the methods of the present application.

[0052] In the sixth aspect, the present application provides an electronic device, the electronic device comprises a memory and a processor, the memory stores a computer program, and the processor realizes the steps of any of the methods of the present application or the functions of the device of the present application when executing the computer program.

[0053] In a seventh aspect, the present application provides a computer readable storage medium storing computer instructions, when the computer instructions are read by a computer, the computer executes the steps of any one of the methods of the present application.

[0054] Compared with the prior art, the present application has the beneficial effect that the dose control method of the existing accelerator software and hardware system is used to solve the problem of ultra-high dose rate of the equipment in the Flash debugging process, the pulse period number of the output beam current charge and the pulse width of the ion source voltage are accurately controlled, the output dose rate of the proton beam is accurately controlled, the shielding function of the proton room is not additionally increased, the Flash dose debugging of the proton treatment equipment is possible in the conventional proton room, the economic cost caused by the additional huge shielding wall is saved, the dose rate control can be realized by controlling the pulse period number, the pulse width of the ion source voltage can be directly controlled by the pulse width mapping curve, the flexibility makes the method suitable for different application scenarios and needs, has wide applicability, the control accuracy and efficiency can be further improved through the iterative optimization of the pulse width mapping curve, and the Flash dose debugging is beneficial to realize the Flash radiotherapy. BRIEF DESCRIPTION OF DRAWINGS

[0055] The present application will be further described below in combination with the accompanying drawings and specific embodiments.

[0056] Fig. 1 is a schematic diagram of the load shielding design of a conventional proton accelerator room;

[0057] Fig. 2 is a schematic diagram of the proton beam dose control method of the embodiment of the present application;

[0058] Fig. 3 is a schematic diagram of the flow of the proton beam dose control method of the embodiment of the present application;

[0059] Fig. 4 is a schematic diagram of the duty cycle control logic of the proton beam dose control method of the embodiment of the present application;

[0060] Fig. 5 is a schematic diagram of the accelerator timing cycle of the embodiment of the present application;

[0061] Fig. 6 is a schematic diagram of the pulse width control logic of the proton beam dose control method of the embodiment of the present application;

[0062] Fig. 7 is a schematic diagram of the pulse width mapping curve of the embodiment of the present application;

[0063] Fig. 8 is a schematic diagram of the particle accelerator of the embodiment of the present application;

[0064] Fig. 9 is a schematic diagram of the medical system of the embodiment of the present application;

[0065] Fig. 10 is a schematic diagram of the medical system debugging flow of the embodiment of the present application. DETAILED DESCRIPTION

[0066] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and fully convey the inventive aspects of the example implementations to those skilled in the art.

[0067] Since the Flash high-intensity beam releases a large particle dose in a very short time, high requirements are placed on the radiation shielding wall, in other words, the site where the Flash radiotherapy is implemented has a strong radiation shielding capability, which requires that the radiation shielding wall be made thick enough, so that the wall occupies a large area, a large amount of capital investment is required, and more stringent design specifications need to be added on the basis of the existing proton machine room design, and the requirements of environmental impact assessment will also be increased. The particles can be protons, heavy ions or electrons.

[0068] Taking the proton therapy system debugging machine room as an example, according to the standard of radiation protection, the shielding external dose rate control level is shown in Table 1:

[0069] Table 1:

[0070] Among them, the occupancy factor refers to the proportion of the average time of the maximum exposed personnel in the area in the beam time of the radiation source. The dose rate refers to the radiation energy absorbed per unit time, which is usually measured in units of millisievert or microsievert, and it is an important safety index for measuring the impact of radiation on human health.

[0071] 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 the existing accelerator software and hardware system to control the dose, and does not need to increase the shielding function of the particle accelerator room, so that the dose debugging of Flash can be realized in a conventional particle accelerator room.

[0072] Among them, the ordinary proton accelerator room load shielding design refers to FIG. 1. FIG. 1 is a schematic diagram of the load shielding design of the ordinary proton accelerator room.

[0073] In the system service debugging mode of the hospital, two control modes are added in the clinical operation mode, which are Flash mode and normal mode. In the clinical operation mode, the Flash dose rate control is realized through the Flash debugging mode. Before the debugging of the radiation chain system, the selection buttons of the normal mode and the Flash mode are added. The system parameter combination of the normal mode will only take effect when the normal mode is selected, and the system parameter combination of the Flash mode will only take effect when the Flash mode is selected. This kind of radiation chain control mode can ensure the safety of the system radiation dose. In the normal mode, the Flash beam current cannot be output, and only in the Flash mode can the measurement control system configuration in the Flash mode be output. The service debugging mode includes debugging and maintenance modes, and the clinical operation mode is a mode used when treating patients.

[0074] The proton therapy equipment is installed in the area of the hospital. When the Flash proton is debugged or treated, the dose rate output by the machine should be effectively measured and controlled in one to three layers of the ordinary proton accelerator machine room. The machine can be a particle accelerator.

[0075] Embodiment of the proton beam dose control method:

[0076] Referring to FIG. 2 and FIG. 3, FIG. 2 is a schematic diagram of the proton beam dose control method according to an embodiment of the present application,

[0077] FIG. 3 is a flowchart of the proton beam dose control method according to an embodiment of the present application;

[0078] Some embodiments of the present application provide a proton beam dose control method, which comprises:

[0079] Obtaining the proton beam output dose requirement;

[0080] Through the Flash debugging mode, the number of pulse periods of the output beam current is controlled within a preset time; and / or,

[0081] Through the pulse width mapping curve, the pulse width of the ion source voltage is controlled to realize the control of the proton beam output dose rate. The pulse width mapping curve is a corresponding relationship curve of the pulse width and the charge quantity (PC). In the present application, the pulse width (PW) is represented as a PWC curve. The pulse width can be adjusted within 0-30uS.

[0082] In some possible implementations, the pulse width output range is obtained by adjusting the duty cycle, and the pulse width is adjusted through the pulse width mapping curve. The two methods are used in combination to realize the control of the output dose.

[0083] The working principle of the above technical solution is that if the dose rate is to be reduced in the Flash mode, there are the following implementation forms, the first way is that in a certain time T (T>t), the accelerator pulse period is t, and part of the pulse period has no beam output, the second method is that each pulse has beam output, but the charge amount of each pulse is reduced through the pulse width mapping curve, that is, the pulse width of the ion source voltage is reduced, and both can be performed simultaneously, and the number of pulse periods of the output beam in the preset time period, that is, the duty cycle and the pulse width of each pulse are controlled simultaneously, so as to realize the control of the proton beam output dose rate.

[0084] The effect of the above technical solution is that by controlling the number of pulse periods and the pulse width of the ion source voltage (that is, the output charge amount), the accurate control of the proton beam output dose rate can be realized; the predetermined dose for the treatment area can be ensured, and the irradiation of the healthy tissue is reduced; a plurality of dose rate reduction modes are provided, including adjusting the pulse period and the pulse width, so that the operator can flexibly adjust the dose rate according to the specific condition of the patient and the treatment demand; 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 the dose control; in addition, the separation selection mechanism of the Flash mode and the conventional mode ensures that the high dose rate output is only enabled in the Flash mode, further reducing the risk of misoperation; without additional increase of the shielding function of the proton room, the equipment cost is reduced; at the same time, the dose control is realized by using the existing accelerator software and hardware system, improving the utilization rate and economic benefit of the equipment; by adding the Flash mode and the conventional mode selection buttons in the system service debugging mode and the clinical operation mode of the hospital, the operation process is simplified, and the operator can conveniently switch between the two modes and adjust and control the dose rate as needed.

[0085] In some possible implementation manners, the control of the number of pulse periods of the output beam charge in the preset time includes:

[0086] According to the demand of the proton beam output dose, a plurality of duty cycles are preset;

[0087] The duty cycle is executed by the radio frequency control module to control the output power of the radio frequency amplifier in each pulse period, so as to realize the control of the proton beam output dose rate, and the radio frequency control module includes an FPGA counting module;

[0088] The duty cycle control logic diagram refers to FIG. 4, which is a duty cycle control logic diagram of the proton beam dose control method of the embodiment of the application.

[0089] The working principle and effects of the above technical solution are as follows: in the Flash mode, if it is desired to reduce the dose rate, the first mode is that, in a certain time T (T>t), the accelerator pulse period is t, and part of the pulse period has no beam output, for the convenience of calculation, T can be selected as an integer multiple of t, the unit t of the present 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) wherein: T1+T2=T; T1 and T2 are integer multiples of t; the boundary conditions of the two T1 and T2 are: when T1=T, T2=0, the output dose rate is the maximum dose rate D1, when T2=T, the dose rate output dose rate is 0, and the dose rate calculation formula of other conditions is: D=T1 / T×D1.

[0090] Referring to FIG. 5, FIG. 5 is an accelerator timing cycle schematic diagram of an embodiment of the present application;

[0091] For example: if there are 5 accelerator pulse periods t in the total time T, that is, T=5t, T1=t, T2=4t, and only once t (that is, one pulse period) has beam output, and the pulse width is a maximum fixed value, then in the total T time, 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 output beam pulse period to the total pulse period, that is, the duty cycle (BRD is used instead in the present embodiment), can be set, wherein the duty cycle range can be 1 / 100-1 / 2, for example, the duty cycle is 1 / 2, 1 / 5, 1 / 10, 1 / 20, 1 / 50, and 1 / 100, and under the same pulse width, the dose rate will also change to 1 / 2, 1 / 5, 1 / 10, 1 / 20, 1 / 50, and 1 / 100. The radio frequency control module controls the radio frequency amplifier, the counting is realized based on the FPGA control module, and the duty cycle is realized by controlling the radio frequency power output. Through the combination of software and hardware, the problem of high dose rate output of the accelerator in the Flash mode can be effectively controlled, and the Flash debugging of the proton therapy equipment can be performed on the spot in the hospital without Flash environmental evaluation and changing the thickness of the infrastructure wall.

[0092] In some possible implementation manners, the method further includes:

[0093] 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 a first preset range;

[0094] 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.

[0095] In some possible implementation manners, the method further includes:

[0096] acquiring an output charge amount corresponding to a maximum pulse width of the ion source voltage when a duty cycle is 1;

[0097] taking a ratio of the maximum safe output charge amount to the output charge amount as a first ratio, and the first preset threshold being less than or equal to the first ratio;

[0098] obtaining a relationship between the duty cycle and the first ratio;

[0099] determining a range of the pulse width of the ion source voltage according to the relationship between the duty cycle and the first ratio.

[0100] The working principle of the above technical solution is as follows: the duty cycle (BRD) is defined as the proportion of the number of pulse periods with beam output to the total number of pulse periods; 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 amount of the proton beam in each pulse period; the longer the pulse width, the greater the charge amount, and thus the greater the dose contribution; in order to establish a correlation between the 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 if the maximum pulse width is used, the beam output dose rate can still be within the 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 within the second preset range, ensuring that the beam output dose rate is within the safe range; multiple thresholds can be set, and here only two thresholds are used as an example.

[0101] wherein the output charge amount corresponding to the maximum pulse width of the ion source voltage when the duty cycle is 1 (i.e. all pulse periods have beam output) is acquired, which represents the maximum dose that the ion source voltage can produce at the maximum pulse width; the maximum safe output charge amount is determined, which is usually the upper limit of the safe dose; the ratio of the maximum safe output charge amount to the output charge amount 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 output dose rate can still be within the safe range; if the duty cycle is greater than the first ratio, the pulse width of the ion source voltage is reduced in proportion according to the safe dose requirement and the value of the duty cycle, and a pulse width threshold is set, thereby ensuring that the beam output dose rate is within the safe range.

[0102] The technical scheme has the following beneficial effects: the combination of the adjustment of the duty cycle (BRD) and the control of the ion source voltage pulse width realizes accurate control of the proton beam output dose rate; the combination control strategy enables flexible adjustment of the dose rate according to treatment requirements, and meets the treatment requirements of different patients; multiple threshold values and corresponding pulse width ranges can be set, ensuring that the ion source voltage pulse width can be controlled within a suitable range under different duty cycles, thereby avoiding harm to patients caused by excessively high dose rates; the ratio of the maximum safe output charge amount to the corresponding output charge amount of the maximum pulse width is calculated as the basis for adjusting the duty cycle, further ensuring the safety of the treatment process; the dose control is realized by combining software control and hardware adjustment using the functions of the existing accelerator software and hardware system, without the need for additional expensive equipment or complex modification, thereby reducing equipment costs; and the combination of the software and hardware based on the FPGA control technology makes the maintenance of the system more simple and convenient, thereby reducing maintenance costs.

[0103] In summary, the technical scheme improves the safety and flexibility of treatment, and reduces equipment costs and maintenance costs by accurately controlling the dose rate of the proton beam.

[0104] Referring to FIGS. 6 and 7, FIG. 6 is a pulse width control logic diagram of the proton beam dose control method according to an embodiment of the present application, and FIG. 7 is a pulse width mapping curve diagram according to an embodiment of the present application.

[0105] In some possible implementation manners, the control of the ion source voltage pulse width through the pulse width mapping curve comprises:

[0106] The ion source voltage pulse width is obtained through the pulse width mapping curve, and different charge amounts are obtained.

[0107] The ion source voltage pulse width is controlled, the output charge amount is controlled, and thus the control of the output dose rate is realized.

[0108] The working principle of the technical scheme is as follows: if each pulse has a charge output, or the set value of the duty cycle is greater than a first preset threshold value, in order to realize dose control, the ion source hydrogen ionization cathode voltage pulse width needs to be controlled; when there is cathode voltage, hydrogen gas is ionized into plasma mainly composed of hydrogen ions; when there is no cathode voltage, hydrogen gas is not ionized; different ion source cathode voltage pulse widths are calibrated to correspond to different charge amounts; the corresponding relationship between the calibrated ion source cathode voltage pulse width and the charge amount is debugged through a specific beam spot map, the beam spot map includes beam spot information, beam spot position coordinates, energy, and charge amount information; then the beam spot map is stored in the form of an Xml file, and the stored file is used for accurate dose control; for example, if it is desired to output 4.5 pc of charge amount per pulse, only the ion source pulse width needs to be set to 2.5 us.

[0109] The above technical solution has the following effects: by calibrating and storing the corresponding relationship between the ion source cathode voltage pulse width and the charge amount, the system can accurately control the charge amount 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 charge amount, accurate dose control can be achieved by simple settings without complex calculations and debugging, which simplifies the operation process, reduces the operation difficulty, and improves the work efficiency; storing the corresponding relationship between the pulse width and the charge amount in the form of an xml file makes the system easy to extend and maintain; when the corresponding relationship needs to be updated or modified, only the corresponding xml file needs to be modified, without the need to make large-scale changes to the entire system, thereby reducing the maintenance cost and improving the flexibility and scalability of the system. Through accurate dose control and simplified operation process, the possibility of human error is reduced, and the reliability and stability of the system are improved. This is crucial for ensuring the safety and effectiveness of the radiotherapy process.

[0110] In some possible implementations, the method for obtaining the pulse width mapping curve comprises:

[0111] At a preset duty cycle, a plurality of charge amounts are obtained, and a preset pulse width mapping curve is obtained by calibrating the slope and the difference; wherein each charge amount is an average of the charge amounts obtained by a plurality of pulses;

[0112] The preset pulse width mapping curve is debugged by ion source device parameters and radio frequency device parameters to obtain a debugged pulse width mapping curve;

[0113] The output is verified by the cross duty cycle and the pulse width ratio, and the pulse width mapping curve is iteratively optimized according to the verification result.

[0114] The working principle of the above technical solution is: since the duty cycle control method is implemented by counting based on the FPGA control module, the duty cycle is executed by controlling the radio frequency power output; the ion source cathode voltage pulse mode is to control the opening of the ion source cathode voltage, which is to control the plasma charge quantity of hydrogen ionization, the former has a strict linear multiple relationship, and the latter usually does not have a strict linear proportional relationship due to the complexity of plasma ionization and the response of uS order control. At this time, PWC debugging is needed, and after multiple iterations of adjusting system parameters such as ion source frequency and high-frequency frequency, a strict corresponding relationship between ion source pulse width and charge output is formed. The characteristics of this corresponding relationship have continuity and smoothness; due to the influence of many factors such as high-voltage power supply, control module, ion source frequency, radio frequency, and timing, complex debugging and calibration are needed. Starting from the requirement of dose control, the PWC (Pulse width Curve) curve must be monotonic and smooth, which requires strict debugging test and stability test. The specific method is as follows:

[0115] Under the preset duty cycle, multiple pulses are generated by the ion source or related equipment. The preset duty cycle can be a certain value less than the first preset threshold; under the preset duty cycle, the preset slope of charge / pulse width is used as the initial default charge and pulse width mapping corresponding relationship, wherein the preset slope of charge / pulse width can be charge / pulse width=2, and multiple charge quantities are obtained. Each charge quantity information is obtained by averaging multiple (for example: 100) same pulses. Using the average charge quantity and the corresponding pulse width, the preset pulse width mapping curve is drawn or fitted by calibrating the slope (i.e. the slope of the change of the charge quantity with the pulse width) and the possible difference calculation.

[0116] The working parameters of the ion source device and the radio frequency device, such as the accelerator ion source voltage opening frequency, the ion source voltage value, the ion source hydrogen flow, the radio frequency opening frequency, and the radio frequency power output, directly affect the generation of pulses and the amount of electric charge. According to the actual parameters of these devices, the preset pulse width mapping curve is debugged to more accurately reflect the actual working condition. 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; different combinations of duty cycle and pulse width ratio are selected, the corresponding pulses are generated by the ion source device, and the generated electric charge is measured; the measured values are compared with the values predicted according to 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.; the output verification of the cross-duty cycle and pulse width ratio is repeated until the error between the predicted values of the pulse width mapping curve and the actual measured values reaches an acceptable range.

[0117] The effect of the above technical solution is that by obtaining multiple electric charge amounts at a preset duty cycle and calculating the average, the error caused by single measurement is reduced, and the accuracy of the electric charge data is improved; the preset pulse width mapping curve obtained using the calibration slope and the difference calculation provides a relatively accurate initial basis for subsequent debugging and optimization; considering the influence of ion source device and radio frequency device parameters on the electric charge output, the preset pulse width mapping curve can be debugged to make it more suitable for the working conditions of the actual device, improving the practicality and accuracy of the pulse width mapping curve.

[0118] In some possible implementations, the preset pulse width mapping curve is debugged by ion source device parameters and radio frequency device parameters to obtain a debugged pulse width mapping curve; including:

[0119] A plurality of groups of duty cycles are set, each group of duty cycles corresponding to a group of pulse widths, and the output electric charge is tested, wherein the product of each group of duty cycles and the corresponding pulse width is a constant value; as shown in Table 2;

[0120] Table 2:

[0121] The test is repeated multiple times, and if the difference in the output electric charge within a preset time is within a preset difference threshold, the debugged pulse width mapping curve is determined as the final debugged pulse width mapping curve; for example, five groups of different BRD and corresponding ion source pulse width configurations are tested for electric charge output from Table 2, and the average value is obtained by multiple measurements, and the difference between the five groups of data is within a very small range (for example, 10%), which is verified.

[0122] 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 "on" time of the pulse in the total time. During debugging, multiple different duty cycles will be set, and each duty cycle corresponds to a specific pulse width. Importantly, the product of each duty cycle and the corresponding pulse width is a constant value, which ensures that the total energy (or total accumulation of charge quantity) of the pulse remains consistent under different duty cycles, so that the influence of different duty cycles on the charge quantity output can be compared fairly. For each set of duty cycle and corresponding pulse width, a pulse is generated by the ion source device, and the output charge quantity is measured. This charge quantity represents the charge quantity that the ion source device can generate under the given duty cycle and pulse width. To ensure the accuracy and reliability of the test results, multiple repeated tests will be performed for each duty cycle and pulse width combination.

[0123] The charge quantity is output continuously for a certain period of time (such as a week), and the differences between these charge quantities are observed; if these differences are within the preset difference threshold range (i.e., the change in charge quantity is within an acceptable range), the test results are considered stable and reliable; based on the results of multiple tests, the output of the charge quantity 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 more accurately reflect the working characteristics of the ion source device 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.

[0124] In some possible implementations, the output verification by cross-duty cycle and pulse width ratio, and the iterative optimization of the pulse width mapping curve according to the verification result, include:

[0125] The pulse width of different ion source voltages is extracted from the preset pulse width curve, and the corresponding duty cycle is taken as the first duty cycle, and the corresponding output charge quantity is recorded as the first output charge quantity;

[0126] 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;

[0127] The first duty cycle is set as the ratio of the first verification pulse width to the maximum pulse width, the first verification pulse width is obtained, and the second ratio is taken as the second duty cycle corresponding to the first verification pulse width, and the second output charge quantity is obtained;

[0128] The difference between the first output charge quantity and the second output charge quantity is compared to determine whether it is within the preset range; if not, the curve is optimized;

[0129] The iterative optimization is performed through multiple cross-verification results.

[0130] The working principle of the above technical solution is: in the process of iteratively optimizing the pulse width mapping curve, an effective method is to perform output verification through the cross duty cycle and pulse width ratio. The core idea of this method is to compare the output charge obtained under different duty cycle and pulse width settings to evaluate the accuracy of the current pulse width mapping curve, and to perform necessary optimization according to the verification result.

[0131] From the preset pulse width mapping curve, select the pulse width values under different ion source voltages and the corresponding duty cycles as the first duty cycles. 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 to calculate their ratio, obtaining the second ratio. This ratio reflects the scaling degree of the current pulse width relative to the maximum pulse width.

[0132] Let the first duty cycle (i.e., the originally set duty cycle) be equal to the ratio of the first verification pulse width (a hypothetical pulse width value) to the maximum pulse width. According to this assumption, the first verification pulse width can be calculated. Take the second ratio calculated in the second step as the second duty cycle corresponding to the first verification pulse width. Then, set this second duty cycle and the first verification pulse width on the ion source device, and record the output charge at this time 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 to smooth the entire curve to reduce such inconsistency.

[0133] To ensure that the optimized pulse width mapping curve works accurately under various conditions, multiple cross-verifications are needed. This includes selecting different combinations of ion source voltages, pulse widths, and duty cycles and repeating the above verification process. According to the result of each verification, iteratively optimize the pulse width mapping curve until consistent and accurate output charges are obtained under various conditions.

[0134] The effect of the above technical solution is that the cross-validation method can comprehensively verify the accuracy of the pulse width mapping curve under different combinations of ion source voltages, pulse widths, and duty cycles. 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 based on the difference between the actual output charge and the expected value, making it more suitable for the actual working performance of the ion source device. This adaptability enables the pulse width mapping curve to provide more reliable support in practical applications; multiple cross-validation and iterative optimization can ensure the stability and consistency of the pulse width mapping curve. Through repeated verification and adjustment, potential errors and biases can be eliminated, improving the reliability of the pulse width mapping curve.

[0135] Proton beam dose control device embodiments:

[0136] The embodiments of the present application provide a proton beam dose control device, which comprises:

[0137] A demand acquisition module is configured to acquire a proton beam output dose demand.

[0138] A debugging module is configured to control the number of pulse periods of output beam current charge within a preset time through a Flash debugging mode; and / or,

[0139] 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.

[0140] In some possible implementation manners, the debugging module comprises a first debugging unit and a second debugging unit, the first debugging unit is configured to control the number of pulse periods of output beam current charge within a preset time; and the second debugging unit is configured to control the pulse width of the ion source voltage through the pulse width mapping curve to achieve control of the proton beam output dose rate.

[0141] The first debugging unit comprises:

[0142] A preset duty cycle unit is configured to preset a plurality of duty cycles according to the demand of the proton beam output dose.

[0143] A first control unit is configured to control the output power of the radio frequency amplifier in each pulse period by executing the duty cycle through a radio frequency control module, thereby achieving control of the proton beam output dose rate, and the radio frequency control module comprises an FPGA counting module.

[0144] In some possible implementation manners, the first control unit comprises:

[0145] A first control subunit is configured to control the pulse width of the ion source voltage 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.

[0146] a second control subunit configured to control the pulse width of the ion source voltage within a second preset range if the duty cycle is greater than a second preset threshold.

[0147] In some possible implementation manners, the first debugging unit further includes:

[0148] a first acquisition unit configured to acquire an output charge amount corresponding to a maximum pulse width of the ion source voltage when the duty cycle is 1;

[0149] a first threshold setting unit configured to set a ratio of the maximum safe output charge amount to the output charge amount as a first ratio, and the first preset threshold is less than or equal to the first ratio;

[0150] a range determination unit configured to obtain a relationship between the duty cycle and the first ratio, and determine the range of the pulse width of the ion source voltage according to the relationship between the duty cycle and the first ratio.

[0151] In some possible implementation manners, the second debugging unit includes:

[0152] a charge amount acquisition unit configured to obtain different charge amounts corresponding to the pulse width of the ion source voltage through a pulse width mapping curve;

[0153] a second control unit configured to control the pulse width of the ion source voltage to control the output charge amount, so as to realize control of the output dose rate.

[0154] In some possible implementation manners, the second debugging unit includes:

[0155] obtaining a plurality of charge amounts under a preset duty cycle, and obtaining a preset pulse width mapping curve through calibration slope and difference calculation, wherein each charge amount is an average of charge amounts obtained through a plurality of pulses;

[0156] debugging the preset pulse width mapping curve through ion source device parameters and radio frequency device parameters to obtain a debugged pulse width mapping curve;

[0157] performing output verification through a cross duty cycle and a pulse width ratio, and iteratively optimizing the pulse width mapping curve according to a verification result.

[0158] In some possible implementation manners, the second debugging unit includes:

[0159] setting a plurality of groups of duty cycles, each group of duty cycles corresponding to a group of pulse widths, and testing an output charge amount, wherein a product of each group of duty cycles and the corresponding pulse width is a constant value;

[0160] The test is repeated multiple times, and if the difference in the output charge amount in the preset time is within the preset difference threshold range, the debugged pulse width mapping curve is determined as the final debugged pulse width mapping curve.

[0161] In some possible implementation manners, in the second debug unit, the output verification is performed by using the cross duty cycle and pulse width ratio value, and the pulse width mapping curve is iteratively optimized according to the verification result, including:

[0162] The pulse width corresponding to different ion source voltages is extracted from the preset pulse width curve, and the corresponding duty cycle is taken as the first duty cycle, and the corresponding output charge amount is recorded as the first output charge amount;

[0163] 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;

[0164] The first duty cycle is set as the ratio of the first verification pulse width to the maximum pulse width, the first verification pulse width is obtained, and the second ratio is taken as the second duty cycle corresponding to the first verification pulse width, and the second output charge amount is obtained;

[0165] Whether the difference between the first output charge amount and the second output charge amount is within the preset range is compared, and if not, the curve is optimized;

[0166] The verification result is iteratively optimized through multiple cross verifications.

[0167] The working principle and effects of the above technical solution are the same as those of the corresponding principle and effects in the proton beam dose control method of the embodiment of the present application, and are not repeated here.

[0168] Particle accelerator embodiment:

[0169] Referring to FIG. 8, FIG. 8 is a schematic diagram of a particle accelerator according to an embodiment of the present application;

[0170] The embodiment of the present application further provides a particle accelerator, which comprises:

[0171] The ion source system, the high-frequency system, and the proton beam dose control device according to any of the embodiments of the present application;

[0172] The ion source output dose of the ion source system and / or the high-frequency system is controlled by the control device.

[0173] The accelerator can include five subsystems, specifically, an ion source system for providing particles, a vacuum system for providing an environment required for particle acceleration, a magnet system for guiding the direction of particle movement, a high-frequency system for providing energy required for particle acceleration, an extraction system for extracting particles from the inside of the accelerator, and a supporting system for ensuring power supply, cooling, and the like for the accelerator. If it is desired to control the beam to change from extraction to beam stoppage within a very short time period, theoretically, the devices of any one of the six systems in the diagram can be controlled to achieve this, but considering the operability and convenience of stopping and resuming the beam, and the time accuracy of control, especially for the Flash scenario of ultra-high dose rate within a short time, the ion source subsystem and the high-frequency subsystem are preferentially selected to achieve this. The accelerator can be a cyclotron; the particles can be protons, heavy ions, or electrons, and the particle accelerator can be a proton accelerator.

[0174] The embodiment of the present application also provides a particle therapy system, which comprises the aforementioned particle accelerator for providing a Flash beam; the particle therapy system can be a proton therapy system, which comprises a proton therapy device, and the proton therapy device comprises the aforementioned accelerator.

[0175] Embodiment of the medical system:

[0176] Referring to FIG. 9, which is a schematic diagram of a medical system according to an embodiment of the present application;

[0177] The embodiment of the present application also provides a medical system, which comprises:

[0178] The service debugging mode and the clinical operation mode;

[0179] The service debugging mode comprises a Flash debugging mode;

[0180] The Flash debugging mode is realized by the dose control method according to any one of the embodiments of the present application.

[0181] Referring to FIG. 10, which is a schematic diagram of a debugging flow of a medical system according to an embodiment of the present application;

[0182] The radiation chain system adds selection buttons of the normal mode and the Flash mode before debugging the clear field. The system parameter combination of the normal mode is only valid when the normal mode is selected, and the system parameter combination of the Flash mode is only valid when the Flash mode is selected. This radiation chain control mode can ensure the safety of the system radiation dose. In the normal mode, Flash proton beam cannot be generated, and only in the Flash mode, the dose control system configuration in the Flash mode can be generated by adjusting the BRD and the PW to control the Flash dose.

[0183] The electronic device includes a memory and a processor. The memory stores a computer program. The processor implements the steps of the method or the functions of the apparatus when executing the computer program.

[0184] The computer readable storage medium is used to store a computer program. The computer program is executed to implement the steps of the method. The specific implementation and the achieved technical effects are the same as those of the method embodiments, and some contents will not be described here.

[0185] In the present application, the readable storage medium can be any tangible medium containing or storing a program, which can be used by or in combination with an instruction execution system, apparatus or device. The 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 may, for example, be but is not limited to an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, apparatus or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: electrical connection with one or more conductive wires, portable disk, 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 device, magnetic storage device, or any suitable combination of the above.

[0186] A computer readable storage medium can include a non-transitory storage medium (i.e., a medium that does not rely on propagated data signals) to exclude propagated data signals per se. The computer readable storage medium can include data signals transitory outside of a specific apparatus such as between computing devices. The computer readable storage medium can also include data that a specific apparatus changes from one specific state into another. A computer readable storage medium can also be described as a processor readable medium. A computer readable storage medium can be any available medium or device that is accessible by a processor to provide or store information applicable to the employment of, or working of, one or more embodiments. By way of example, and not limitation, a computer readable storage medium can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of computer readable instructions or data structures and that can be accessed by a general purpose or special purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or any other wired or wireless transmission or connection, then the coaxial cable, fiber optic cable, twisted pair, DSL, or any other wired or wireless transmission or connection is properly termed a computer readable medium. Combinations of the above should also be included within the scope of computer readable media.

Claims

1. A flash beam current dose control method, the method comprising: obtaining a flash beam output dose requirement; controlling a number of pulse periods of output beam current charges within a preset time through a flash debugging mode; and / or controlling a pulse width of an ion source voltage through a pulse width mapping curve to achieve control of a flash beam output dose rate. The controlling of the number of pulse periods of output beam current charges within the preset time comprises:

2. The control method according to claim 1, wherein presetting a plurality of duty cycles according to the flash beam output dose requirement; controlling output power of a radio frequency amplifier in each pulse period through a radio frequency control module to implement control of the flash beam output dose rate, the radio frequency control module comprising an FPGA counting module. The method further comprises:

3. The control method according to claim 2, wherein if the duty cycle is greater than a first preset threshold and less than or equal to a second preset threshold, controlling the pulse width of the ion source voltage to be within a first preset range; if the duty cycle is greater than the second preset threshold, controlling the pulse width of the ion source voltage to be within a second preset range. The method further comprises:

4. The control method according to claim 3, wherein obtaining an output charge amount corresponding to a maximum pulse width of the ion source voltage when the duty cycle is 1; taking a ratio of a maximum safe output charge amount to the output charge amount as a first ratio, the first preset threshold being less than or equal to the first ratio; obtaining a relationship between the duty cycle and the first ratio; determining a range of the pulse width of the ion source voltage according to the relationship between the duty cycle and the first ratio. The controlling of the pulse width of the ion source voltage through the pulse width mapping curve comprises:

5. The control method according to claim 1, wherein obtaining different charge amounts corresponding to the pulse width of the ion source voltage through the pulse width mapping curve; controlling the pulse width of the ion source voltage to control the output charge amount, thereby achieving control of the output dose rate. The method of obtaining the pulse width mapping curve comprises:

6. The control method according to claim 1, wherein obtaining a plurality of charge amounts at a preset duty cycle, and obtaining a preset pulse width mapping curve through calibration of a slope and a difference value, wherein each charge amount is an average of charge amounts obtained through a plurality of pulses; debugging the preset pulse width mapping curve through ion source device parameters and radio frequency device parameters to obtain a debugged pulse width mapping curve; performing output verification through a cross duty cycle and a pulse width ratio, and iteratively optimizing the pulse width mapping curve according to a verification result. The debugging of 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 comprises:

7. The control method according to claim 6, wherein setting a plurality of groups of duty cycles, each group of duty cycles corresponding to a group of pulse widths, and testing an output charge amount, wherein a product of each group of duty cycles and the corresponding pulse width is a constant value; repeating the test a plurality of times, and if a difference in the output charge amount is within a preset difference threshold range within a preset time, determining the debugged pulse width mapping curve as a final debugged pulse width mapping curve. The output verification through the cross duty cycle and the pulse width ratio, and the iteratively optimizing of the pulse width mapping curve according to the verification result comprises:

8. The control method according to claim 6, wherein extracting pulse widths of different ion source voltages and corresponding duty cycles as first duty cycles from the preset pulse width curve, and recording corresponding output charge amounts as first output charge amounts; ​ The extracted pulse width is set as a first pulse width, and a ratio of the first pulse width to the maximum pulse width is obtained as a second ratio; The first duty cycle is the ratio of the first verification pulse width to the maximum pulse width, and the first verification pulse width is obtained, and the second ratio is the second duty cycle corresponding to the first verification pulse width, and the second output charge amount is obtained; If the difference between the first output charge amount and the second output charge amount is not within the preset range, curve optimization is performed; Through multiple cross-validation results, iterative optimization is performed.

9. A Flash beam dose control device, the device comprising: a demand acquisition module for acquiring a Flash beam output dose demand; a Flash debugging module for controlling the number of pulse cycles of the output beam current within a preset time through a Flash debugging mode; and / or, controlling the pulse width of the ion source voltage through a pulse width mapping curve to achieve control of the Flash beam output dose rate.

10. A particle accelerator, the particle accelerator comprising: an ion source system, a high frequency system, and the control device of claim 9; controlling the ion source output dose of the ion source system and / or the high frequency system through the control device.

11. A particle therapy system, the particle therapy system comprising the particle accelerator of claim 10.

12. A medical system, the system comprising: a service debugging mode and a clinical operation mode; the service debugging mode comprises a Flash debugging mode; the Flash debugging mode realizes the control of the beam dose through the method of any one of claims 1-8.

13. An electronic device, the electronic device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the method of any one of claims 1-8 or the functions of the device of claim 9 when executing the computer program.

14. A computer readable storage medium, the storage medium storing computer instructions, and when a computer reads the computer instructions, the computer executes the steps of the method of any one of claims 1-8 or the functions of the device of claim 9.

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