Beam transmission system and method

Abstract

The invention provides a beam transmission system, which comprises a striping ionization chamber, a front-end multi-channel current integration electronics module and a beam transmission module, the striping ionization chamber generates current signals by using beams, the front-end multi-channel current integration electronics module comprises a plurality of channels, and the channels are used for calculating actual positions of the beams based on the current signals according to whether replacement of irradiation points is finished or not; the ZYNQ data system is used for judging the deviation between the actual position and the ideal position of the beam current before replacement of the irradiation point is finished and sending an adjusting instruction to the treatment control system according to the deviation, and the adjusting instruction is used for adjusting the beam current; and the treatment control system is used for responding to the adjustment instruction and adjusting the beam current.

Description

Technical Field

[0001] The present disclosure relates to the field of particle therapy technology, and more specifically, to a beam transmission system and method. Background Art

[0002] During proton / heavy ion therapy, tumor lesions are irradiated according to the preset irradiation field and dose. When a point in the irradiation field is irradiated with a sufficient dose, the accelerator magnet current will change to deflect the beam to the next irradiation point until all points in the irradiation field are fully dosed with the preset dose. Each treatment terminal has several dose ionization chambers and stripe ionization chambers, of which the dose ionization chamber is used to monitor the dose of the treatment head beam in real time, and the stripe ionization chamber is used to monitor the position of the treatment head beam in real time. In order to meet the accuracy of dose delivery in the irradiation field, it is necessary to monitor the beam position in real time and ensure that its deviation is within the appropriate range. When the beam deviation is large, the position difference information needs to be fed back to the accelerator power supply system to correct the beam position in real time. When the beam deviation exceeds the allowable range, the beam needs to be shut down in time to avoid incorrect treatment.

[0003] In the process of implementing the concept of the present disclosure, the inventors found that when a certain irradiation point in the irradiation field has irradiated a sufficient dose, the beam will switch to the next irradiation point for irradiation, and it will be judged whether the actual position of the beam is within the appropriate range only after the point switching time ends. This solution can only shut down the beam after the beam is deviated, which is likely to cause more dose leakage. Summary of the invention

[0004] In view of this, the present disclosure provides a beam transmission system and method.

[0005] One aspect of the present disclosure provides a beam delivery system, comprising:

[0006] A stripe ionization chamber is used to utilize the beam current to generate a current signal;

[0007] Front-end multi-channel current integration electronics, including a plurality of channels, the channels are used to calculate the actual position of the beam based on the current signal according to whether the irradiation point is replaced or not;

[0008] A ZYNQ data system is used to determine the deviation between the actual position and the ideal position of the beam before the irradiation point is replaced, and send an adjustment instruction to the treatment control system according to the deviation, wherein the adjustment instruction is used to adjust the beam;

[0009] The treatment control system is used to adjust the beam in response to the adjustment instruction.

[0010] According to an embodiment of the present disclosure, calculating the actual position of the beam based on the current signal according to whether the irradiation point is replaced includes:

[0011] When the irradiation point is replaced, the actual position of the beam is calculated based on the current signal by using a Gaussian-block coordinate descent method;

[0012] When the irradiation point replacement is not completed, the actual position of the beam is calculated using a centroid method based on the current signal.

[0013] According to an embodiment of the present disclosure, sending an adjustment instruction to the treatment control system according to the deviation includes:

[0014] When the deviation is within a first preset range, sending a chain signal, wherein the chain signal is used to stop irradiating the beam;

[0015] When the deviation between the actual position and the ideal position of the beam is within a second preset range, a feedback signal is sent out, and the feedback signal is used to adjust the irradiation parameters of the beam.

[0016] According to an embodiment of the present disclosure, the channel includes a multi-channel weak current integrating analog-to-digital converter, and the multi-channel weak current integrating analog-to-digital converter is used to integrate the current signal;

[0017] The ZYNQ data system is also used to set the numerical baseline of the multi-channel weak current integrating analog-to-digital converter to 0 before the beam irradiation.

[0018] According to an embodiment of the present disclosure, the ZYNQ data system is used to mark the start time and end time of each integration period and the position of the target time within the integration period before the beam irradiation, and the target time is any time between the start time and the end time.

[0019] According to an embodiment of the present disclosure, the beam transmission system further includes a host computer, and the host computer is used to send a calculation threshold to all the channels;

[0020] The front-end multi-channel current integration electronics is also used to calculate the actual position of the beam using the ADC value of the channel when the ADC value corresponding to the channel is greater than the calculation threshold.

[0021] According to an embodiment of the present disclosure, the ZYNQ data system is also used to determine whether the irradiation point has been replaced;

[0022] The determining whether the irradiation point has been replaced includes:

[0023] During the integration period of the multi-channel weak current integration type analog-to-digital converter of the channel, the beam is continuously in the irradiation path of the same irradiation field point, and the irradiation point replacement is completed;

[0024] If the beam does not continue to be on the irradiation path of the same irradiation point within the integration period of the multi-channel weak current integration type analog-to-digital converter of the channel, the irradiation point is not replaced and terminated.

[0025] According to an embodiment of the present disclosure, the ZYNQ data system, wherein the beam is not continuously in the irradiation path of the same irradiation field point, comprises:

[0026] The beam is located on the irradiation path of the first irradiation point at the beginning of the integration period, and is located on the irradiation path from the first irradiation point to the second irradiation point at the end of the integration period;

[0027] The beam is continuously on an irradiation path from the first irradiation field point to the second irradiation field point;

[0028] The beam is located on an irradiation path from the first irradiation point to the second irradiation point at the start time of the integration of the period, and is located on an irradiation path of the second irradiation point at the end time of the integration period;

[0029] The beam is located on the irradiation path of the first irradiation field point at the start time of the integration period, and is located on the irradiation path of the second irradiation field point at the end time of the integration period.

[0030] According to an embodiment of the present disclosure, the host computer is used to send the calculation threshold to the channel when the numerical baseline of the multi-channel weak current integrating analog-to-digital converter is set to 0.

[0031] Another aspect of the present disclosure provides a beam transmission method, comprising:

[0032] According to whether the irradiation point has been replaced, the actual position of the beam is calculated;

[0033] Before the irradiation point is replaced, determining the deviation between the actual position of the beam and the ideal position;

[0034] The beam current is adjusted according to the deviation.

[0035] According to the embodiments of the present disclosure, the stripe ionization chamber uses the beam to generate a current signal. The front-end multi-channel current integration type electronics include multiple channels, which are used to calculate the actual position of the beam based on the current signal according to whether the irradiation point has been replaced. The ZYNQ data system is used to determine the deviation between the actual position and the ideal position of the beam before the irradiation point is replaced, and send an adjustment instruction to the treatment control system according to the deviation, and the adjustment instruction is used to adjust the beam; the treatment control system is used to adjust the beam in response to the adjustment instruction. If the beam is deviated, the beam can be turned off or adjusted before it hits the irradiation point, that is, during the deviating process, to avoid more dose leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0037] Figure 1 The structure diagram of the beam transmission system according to the embodiment of the present disclosure is schematically shown;

[0038] Figure 2 A schematic diagram schematically shows a beam control process according to an embodiment of the present disclosure;

[0039] Figure 3 A schematic diagram schematically shows an iterative process of the Gaussian-block coordinate descent method according to an embodiment of the present disclosure;

[0040] Figure 4 A diagram schematically shows the relationship between the beam current and the timestamp of the front-end multi-channel weak current integrating ADC according to an embodiment of the present disclosure;

[0041] Figure 5 A schematic diagram schematically shows a beam motion trajectory according to an embodiment of the present disclosure;

[0042] Figure 6 A schematic diagram of strip signal fitting according to another embodiment of the present disclosure is schematically shown;

[0043] Figure 7 A flow chart of a beam transmission method according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0045] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0046] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0047] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0048] The embodiment of the present disclosure provides a beam transmission system, including: a striped ionization chamber, used to generate a current signal using a beam; a front-end multi-channel current integration type electronics, including multiple channels, the channels are used to calculate the actual position of the beam based on the current signal according to whether the irradiation point is replaced or not; a ZYNQ data system, used to determine the deviation between the actual position and the ideal position of the beam before the irradiation point is replaced, and send an adjustment instruction to the treatment control system according to the deviation, the adjustment instruction is used to adjust the beam; the treatment control system is used to adjust the beam in response to the adjustment instruction. If the beam deviates, the beam can be turned off or adjusted before it hits the irradiation point, that is, during the deviating process, to avoid more dose leakage.

[0049] Figure 1 The structure diagram of the beam transmission system according to an embodiment of the present disclosure is schematically shown.

[0050] like Figure 1 As shown, the beam transmission system includes a striped ionization chamber, front-end multi-channel current integration electronics, a ZYNQ data system and a treatment control system. The striped ionization chamber is used to generate a current signal using the beam. The front-end multi-channel current integration electronics includes a plurality of channels, and the channels are used to calculate the actual position of the beam based on the current signal according to whether the irradiation point is replaced. The ZYNQ data system is used to determine the deviation between the actual position and the ideal position of the beam before the irradiation point is replaced, and send an adjustment instruction to the treatment control system according to the deviation, and the adjustment instruction is used to adjust the beam. The treatment control system is used to adjust the beam in response to the adjustment instruction. In some embodiments of the present disclosure, the beam transmission system may also include a host computer and an accelerator control system.

[0051] The striped ionization chamber can be a gas detector. When the beam passes through the striped ionization chamber vertically, the gas molecules in the striped ionization chamber will be ionized, generating electron-ion pairs and generating induced charges on the signal plate. The electron-ion pairs will move to the two poles under the action of high voltage and will be finally absorbed by the plate to achieve charge balance. The signal pole of the striped ionization chamber is composed of a series of metal strips. The gas ionization will generate an induced signal on the corresponding strip. The intensity of the induced signal is positively correlated with the degree of gas ionization, and the degree of gas ionization is related to the beam profile. Therefore, the closer to the center of the beam, the higher the ionization of the gas molecules, and the stronger the induced current amplitude signal on the strip at the corresponding position. Because the terminal beam envelope is Gaussian distributed, the current signal amplitude on the strip is also Gaussian distributed in the XY plane. The current amplitude induced on the strip at each position is limited, approximately in the range of 10pA~300nA. Therefore, the current signal generated by the striped ionization chamber is a weak current signal.

[0052] The front-end multi-channel current integration type electronics system can be composed of multiple channels, each of which includes components such as current signal input, integrator, multiplexer, differential output circuit, etc. The front-end multi-channel current integration type electronics converts the weak current signal generated in the striped ionization chamber into a voltage signal and performs integration processing for subsequent data processing and analysis. Since the current signal generated by the striped ionization chamber is very weak, the current signal generated by the striped ionization chamber can be collected in the form of current integration, that is, the charge amount within a period of time is collected as a signal to reduce noise interference. The acquisition time can be determined by the chip, usually tens of us to hundreds of us, and the present disclosure does not limit this.

[0053] The ZYNQ data acquisition and control system can collect the signals output by the front-end multi-channel current integrating electronics, control the performance of the front-end multi-channel current integrating electronics, etc., and interact with the treatment control system for data.

[0054] The host computer is implemented based on C++ code, and its main functions are data display, UI interface operation, and data interaction with the treatment control system and ZYNQ data system.

[0055] See also Figure 2 , Figure 2 A schematic diagram of a beam control process according to an embodiment of the present disclosure is schematically shown.

[0056] During the interaction between the host computer, ZYNQ data acquisition and control system and treatment control system. For slow data, such as the dot matrix information of the irradiation field, the time information of the switching point, the position linkage threshold, etc., the host computer will obtain it from the treatment control system before irradiation and send it to the ZYNQ data acquisition and treatment control system through Ethernet. For fast signals, such as the Beam signal (during beam irradiation), the switching point signal for switching the beam from one irradiation field point to the next irradiation field point, the feedback signal for adjusting the irradiation parameters of the beam and the beam linkage signal for stopping irradiation, etc., the treatment control system and the ZYNQ data acquisition and control system are transmitted in real time through optical fiber to minimize transmission delay.

[0057] In some embodiments of the present disclosure, the ZYNQ data system indicates the start time and end time of each integration period, as well as the position of the target time within the integration period before the beam irradiation. The target time is any time between the start time and the end time. In one embodiment, the ZYNQ data system will perform data synchronization for the multi-channel current integration ADC, that is, indicate the start time and end time of each integration period and the position of a certain time within the integration period, and then wait for the beam irradiation and the Beam signal, and the arrival of the point change signal. At the same time, the host computer obtains the irradiation field dot matrix information, point change time information, and position linkage threshold from the treatment control system and sends them to the ZYNQ data system, which stores them in the form of RAM.

[0058] The current integration period of the present invention feeds back the real-time deviation between the actual beam position and the ideal beam position, providing a current calibration basis for the accelerator power supply system. In the future, it may be possible to calibrate the accelerator terminal beam position in real time.

[0059] In some embodiments of the present disclosure, the ZYNQ data system is used to set the numerical baseline of the multi-channel weak current integration type analog-to-digital converter to 0 before the beam irradiation. In some related schemes, the ADC numerical baseline of the multi-channel weak current integration type ADC is usually not 0, but a specific value, such as 16384. However, the long-term exposure of the chip to a high radiation field may cause the baseline of some channels to drift. For example, the baseline of channel CH121 may shift to 16845 after long-term use, which may cause calculation errors. According to an embodiment of the present disclosure, at the beginning of treatment and before beam irradiation, the ZYNQ data system is started, and the host computer sends a baseline recovery command. The baseline recovery command is used to keep the baselines of different channels near 0. This can avoid position calculation errors caused by different baselines of different channels.

[0060] In some embodiments of the present disclosure, the host computer may send a calculation threshold to all channels based on baseline recovery. In some embodiments of the present disclosure, the calculation threshold may be sent to the channel when the numerical baseline of the multi-channel weak current integrating analog-to-digital converter is set to 0.

[0061] When the ADC value corresponding to a channel is greater than the calculation threshold, the front-end multi-channel current integration electronics uses the ADC value of the channel to calculate the actual position of the beam. It can be understood that only when the ADC value corresponding to the channel is greater than the calculation threshold, the channel will participate in the calculation. At the end of a current integration cycle, the ADC values ​​of 256 channels along the x and y directions of the beam can be obtained. These ADC values ​​will be compared with the calculation threshold after baseline recovery. If the ADC value is greater than the calculation threshold, the ADC value minus the calculation threshold is used for calculation, and accordingly, the strip number corresponding to the ADC value is used for calculation.

[0062] The strip number for the x direction of the stripe ionization chamber (i.e., the x direction of the beam current) is recorded as Mi, and the signal of the strip is recorded as Ni. Mi and Ni are used to calculate the beam current in the x direction. The strip number for the y direction of the stripe ionization chamber (i.e., the y direction of the beam current) is recorded as Ci, and the signal of the strip is recorded as Di. Ci and Di are used to calculate the beam current in the y direction.

[0063] In some embodiments of the present disclosure, depending on whether the irradiation point has been replaced, calculating the actual position of the beam based on the current signal includes: when the irradiation point has been replaced, calculating the actual position of the beam based on the current signal using a Gaussian-block coordinate descent method; when the irradiation point has not been replaced, calculating the actual position of the beam based on the current signal using a center of gravity method.

[0064] The beam position algorithm provided by the present disclosure can be deployed on hardware circuits such as FPGA, and has the characteristics of high parallelism, high flexibility and adaptability. Whether it is a chip with large resources or a chip with small resources, the module parallelism and pipeline level can be adjusted according to their own conditions. It solves the problems of general calculation accuracy of the traditional centroid method, difficulty in deploying the traditional beam Gaussian algorithm on FPGA, uncertainty in the iteration process, and uncertainty in the optimization effect, making it possible to deploy a high-precision, fast, and accurate beam position calculation method on FPGA.

[0065] The following description is made with respect to the x direction, and the y direction may be described in the same manner as the x direction.

[0066] The formula of the center of gravity method is as follows: , the maximum value , beam current RMS .

[0067] (1)

[0068] (2)

[0069] (3)

[0070] The Gaussian-block coordinate descent method uses parameter iterative updating, and the iteration step sizes are . s is the iteration accuracy percentage.

[0071] Gauss's formula is (4), where is the amplitude, is the center calculated by Gaussian method, is the beam current root mean square calculated by Gaussian method, To bring in the strip The signal value obtained. The residual s under this parameter is (5).

[0072] (4)

[0073] (5)

[0074] The iterative process is as follows Figure 3 The position obtained by iteration is denoted as P gb , the maximum value is recorded as M gb , the root mean square is denoted as σ gb .

[0075] During the beam point scanning process, the beam position timestamp and the front-end multi-channel weak current integration ADC timestamp can have Figure 4 There are five relationships shown. Hereinafter, the replacement of the field point is referred to as the point change.

[0076] exist Figure 4 In the figure, the time at point A indicates the time taken for the beam to be released and reach point A in the irradiation field. The time at point B indicates the time taken for the beam to be released and reach point B in the irradiation field. The switching time from point A to point B refers to the time taken for the beam to switch from irradiation field A to irradiation field B, also known as the switching time.

[0077] In some embodiments of the present disclosure, if the beam is continuously in the irradiation path of the same irradiation point during the integration period of the multi-channel weak current integration type analog-to-digital converter, the irradiation point replacement ends. That is, during the integration period, the target irradiation point of the beam is always the same irradiation point. For example, see Figure 4 State 1 in the image is always the wild point A.

[0078] In some embodiments of the present disclosure, if the beam does not continue to be on the irradiation path of the same irradiation point during the integration period of the multi-channel weak current integration type analog-to-digital converter of the channel, the irradiation point is not changed and ended. That is, during the integration period, the target irradiation point of the beam is changed. For example, it is switched from irradiation point A to irradiation point B.

[0079] Furthermore, the above-mentioned beam does not continuously stay in the same irradiation field point on the irradiation path, which may include at least 4 states. Figure 4 , the four states are states 2-5 respectively. State 2, the beam is on the irradiation path of the first field point at the beginning of the integration period, and is on the irradiation path from the first field point to the second field point at the end of the integration period. State 3, the beam continues to be on the irradiation path from the first field point to the second field point. State 4, the beam is on the irradiation path from the first field point to the second field point at the beginning of the integration of the period, and is on the irradiation path of the second field point at the end of the integration period. State 5, the beam is on the irradiation path of the first field point at the beginning of the integration period, and is on the irradiation path of the second field point at the end of the integration period.

[0080] For these five states, the ideal beam position can be calculated. At the end of the integration, the ZYNQ data system will count the proportion of the three time periods of point A, point A to point B, and point B relative to the integration time, calculate the average position of these three intervals, and then calculate the ideal beam position based on the time proportion. Among them, point A and point B are the dot matrix positions issued by the treatment control system, and the average position from point A to point B is calculated by linear fitting, as shown in formula (6), where P A is the position of point A, P B is the position of point B, T AB is the time for points A and B to change points, T C It is the starting timestamp of ADC in the process of changing points, T d is the end timestamp of the ADC in the process of changing points, P AB-avg is the ideal average position of the beam during the switching period. The ideal beam position is obtained by formula (7), where T i is the integration period, t A is the time during the integration period when the beam irradiates point A, t B is the time during the integration period when the beam irradiates point B, P S is the ideal beam position. The constraint conditions are shown in formula (8).

[0081] (6)

[0082] (7)

[0083] (8)

[0084] The beam is deflected by the scanning iron and finally reaches the stripe ionization chamber, as shown in the schematic diagram. Figure 5 According to the deflection-related motion formula of charged particles in a magnetic field, the relationship (9) can be obtained. In actual equipment, L2 is usually much larger than the irradiation field size, for example, About 500mm, Greater than 4000mm, the maximum irradiation field at the isocenter is -100 to +100mm, a total of 200mm long square. At small angles, you can use Alternative ,and It can be obtained from formula (10), where is the charge number of the charged particle, is the magnetic induction intensity, is the mass of the charged particle, is the velocity of the charged particle, is the position where the beam hits the stripe ionization chamber. Thus, formula (9) becomes formula (11), and the maximum error is easily obtained Formula (12) shows that when the maximum irradiation field is reached, the error is the largest, which is 0.027765 mm. This error can be ignored relative to the position linkage threshold, and in actual use, the stripe ionization chamber will be placed a distance in front of the isocenter, so the error is actually smaller. The calculation of magnetic induction intensity can be based on the Biot-Savart law, as shown in formula (13), and the relationship between current and time is shown in formula (14), where k is the measured fitting coefficient and b is the bias. When the accelerator parameters are determined, and is a constant value. When the extraction energy and particles are determined, is a constant value. Combining formulas (11), (13) and (14), we can know that With time There is a linear relationship between them, so the ideal average position of the beam during the point change process can be calculated using formula (7).

[0085] (9)

[0086] (10)

[0087] (11)

[0088] (12)

[0089] (13)

[0090] (14)

[0091] In some embodiments of the present disclosure, sending an adjustment instruction to the treatment control system based on the deviation includes: when the deviation is within a first preset range, issuing an interlocking signal, the interlocking signal is used to stop the irradiation beam; when the deviation between the actual position and the ideal position of the beam is within a second preset range, issuing a feedback signal, the feedback signal is used to adjust the irradiation parameters of the beam.

[0092] In one example, when the deviation is less than the first position interlocking threshold of 0.8mm, no interlocking signal and feedback signal are issued, and there is no need to adjust the beam. When the deviation is greater than the first position interlocking threshold of 0.8mm, it is further determined whether the deviation is greater than the second position interlocking threshold of 1.5mm. If it is greater than the second position interlocking threshold of 1.5mm, an interlocking signal is issued. If it is not greater than the second position interlocking threshold of 1.5mm, a feedback signal is issued.

[0093] It can be understood that the specific value of the position linkage threshold shown in the embodiment of the present disclosure is only for illustration and can be any other value.

[0094] In some specific implementations, at the end of each integration time, the ideal beam position will be consistent with the position P obtained by the actual measurement of the strips g or P gb When the integration period contains a point-changing time, the Gaussian method becomes invalid. With P g Calculate the deviation when the integration period does not contain the switching time. With P gb Calculate the deviation. The ZYNQ data system can send the position interlocking information obtained in each integration cycle to the treatment control system in real time through a single-mode optical fiber. The position interlocking information includes the interlocking signal, the x-direction deviation, and the y-direction deviation. These deviations will be handed over to the treatment control system and transferred to the accelerator power supply system to further determine whether to correct the current size.

[0095] In some specific implementations, the ZYNQ data system can also send the position linkage information and the original signal of each strip to the host computer via Ethernet, and the host computer can store this information in a database for future query.

[0096] Figure 6The waveform of the actual beam signal was simulated and fitted. The signal was generated by superimposing a beam Gaussian distribution signal on a random number as the noise floor, and the fitting threshold subtraction operation was performed on it. The Gaussian-block coordinate descent method program was written in Verilog and the simulation results were obtained using the same signal. Compared with the origin fitting results, the relative deviation of position and RMS is <0.001, and the relative deviation of amplitude is <0.005.

[0097] The core structure of the Gaussian-block coordinate descent method, cal_all_F is the top-level structure, which can summarize the residuals of the 27 parameter arrangements in the above three parameter spaces and find the minimum residual and its new parameters. The Cal_F_Block module is responsible for calculating the residuals corresponding to each parameter arrangement. Due to the characteristics of FPGA parallel computing, these 27 modules can run simultaneously, greatly improving the computing efficiency. This algorithm has been deployed on the ZYNQ data system board with the MCU XC7Z100. If it is deployed on other MCUs (chips with fewer resources), the parallelism can be appropriately reduced and the pipeline level can be increased to save resources. Only a small amount of program changes are needed to complete the deployment of the algorithm. When the Gaussian-block coordinate descent method module uses the maximum delay of the internal IP core (clock cycle 10ns), one iteration takes about 2us. The number of iterations and the iteration step can be adjusted manually, and the iteration effect can be estimated. Taking formula (4), (5), (6) and iterating 10 times as an example, the best optimization effect of position is (9*2+1)*xc=19xc, the best optimization effect of beam RMS is (9*2+1)*σc=19σc, and the best optimization effect of signal amplitude is (9*2+1)*Ac=19*s*M_g. The iteration time is about 20us, which meets the real-time requirements of position linkage.

[0098] Figure 7 A schematic diagram of a beam transmission method according to an embodiment of the present disclosure is schematically shown.

[0099] like Figure 7 As shown, the beam transmission method can be used Figure 1 The beam transmission system shown is implemented. The beam transmission method includes operations S710-S730.

[0100] In operation S710 , the actual position of the beam is calculated according to whether the irradiation point is replaced.

[0101] In operation S720, before the irradiation point replacement is completed, a deviation between an actual position of the beam and an ideal position is determined.

[0102] In operation S730 , the beam current is adjusted according to the deviation.

[0103] In some embodiments of the present disclosure, depending on whether the irradiation point has been replaced, calculating the actual position of the beam based on the current signal includes: when the irradiation point has been replaced, calculating the actual position of the beam based on the current signal using a Gaussian-block coordinate descent method; when the irradiation point has not been replaced, calculating the actual position of the beam based on the current signal using a center of gravity method.

[0104] The sending of adjustment instructions to the treatment control system according to the deviation includes: when the deviation is within a first preset range, issuing an interlocking signal, the interlocking signal being used to stop irradiating the beam; and when the deviation between the actual position and the ideal position of the beam is within a second preset range, issuing a feedback signal, the feedback signal being used to adjust the irradiation parameters of the beam.

[0105] In some embodiments of the present disclosure, the method further includes: before the beam irradiation, setting the numerical baseline of the multi-channel weak current integrating analog-to-digital converter to 0.

[0106] In some embodiments of the present disclosure, the method further includes: before the beam irradiation, marking the start time and end time of each integration period, and the position of the target time within the integration period, the target time being any time between the start time and the end time.

[0107] In some embodiments of the present disclosure, the method further includes: when there is a front-end multi-channel current integration type electronic channel whose corresponding ADC value is greater than the calculation threshold, using the ADC value of the channel to calculate the actual position of the beam.

[0108] In some embodiments of the present disclosure, if the beam is continuously in the irradiation path of the same irradiation point during the integration period of the multi-channel weak current integrating analog-to-digital converter of the channel, the replacement of the irradiation point is completed; if the beam is not continuously in the irradiation path of the same irradiation point during the integration period of the multi-channel weak current integrating analog-to-digital converter of the channel, the replacement of the irradiation point is completed.

[0109] In some embodiments of the present disclosure, the beam is not continuously in the irradiation path of the same irradiation field point, including: the beam is in the irradiation path of the first irradiation field point at the beginning of the integration period, and is in the irradiation path from the first irradiation field point to the second irradiation field point at the end of the integration period; the beam is continuously in the irradiation path from the first irradiation field point to the second irradiation field point; the beam is in the irradiation path from the first irradiation field point to the second irradiation field point at the beginning of the integration of the period, and is in the irradiation path of the second irradiation field point at the end of the integration period; the beam is in the irradiation path of the first irradiation field point at the beginning of the integration period, and is in the irradiation path of the second irradiation field point at the end of the integration period.

[0110] In some embodiments of the present disclosure, when the numerical baseline of the multi-channel weak current integrating analog-to-digital converter is set to 0, the calculation threshold is sent to the channel.

[0111] According to an embodiment of the present disclosure, the method flow according to an embodiment of the present disclosure can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program contains a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication part, and / or installed from a removable medium. When the computer program is executed by a processor, the above-mentioned functions defined in the system of an embodiment of the present disclosure are executed. According to an embodiment of the present disclosure, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0112] The embodiments of the present disclosure also include a computer program product, which includes a computer program, and the computer program contains program code for executing the method provided by the embodiments of the present disclosure. When the computer program product runs on an electronic device, the program code is used to enable the electronic device to implement the method provided by the embodiments of the present disclosure.

[0113] When the computer program is executed by the processor, the above functions defined in the system / device of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0114] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device, a magnetic storage device, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of a signal on a network medium, and downloaded and installed through a communication part, and / or installed from a removable medium. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0115] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can 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 can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0116] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. It can be understood by those skilled in the art that the features recorded in the various embodiments and / or claims of the present disclosure can be combined and / or combined in a variety of ways, even if such a combination or combination is not explicitly recorded in the present disclosure. In particular, without departing from the spirit and teaching of the present disclosure, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0117] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A beam transmission system, comprising: A stripe ionization chamber is used to utilize the beam current to generate a current signal; Front-end multi-channel current integration electronics, including a plurality of channels, the channels are used to calculate the actual position of the beam based on the current signal according to whether the irradiation point is replaced or not; A ZYNQ data system is used to determine the deviation between the actual position and the ideal position of the beam before the irradiation point is replaced, and send an adjustment instruction to the treatment control system according to the deviation, wherein the adjustment instruction is used to adjust the beam; The treatment control system is used to adjust the beam in response to the adjustment instruction.

2. The beam delivery system according to claim 1, wherein: The calculating the actual position of the beam based on the current signal according to whether the irradiation point is replaced includes: When the irradiation point is replaced, the actual position of the beam is calculated based on the current signal by using a Gaussian-block coordinate descent method; When the irradiation point replacement is not completed, the actual position of the beam is calculated using a centroid method based on the current signal.

3. The beam delivery system according to claim 1, wherein: The sending of an adjustment instruction to the treatment control system according to the deviation comprises: When the deviation is within a first preset range, sending a chain signal, wherein the chain signal is used to stop irradiating the beam; When the deviation between the actual position and the ideal position of the beam is within a second preset range, a feedback signal is sent out, and the feedback signal is used to adjust the irradiation parameters of the beam.

4. The beam delivery system according to claim 1, wherein: The channel includes a multi-channel weak current integrating analog-to-digital converter, and the multi-channel weak current integrating analog-to-digital converter is used to integrate the current signal; The ZYNQ data system is also used to set the numerical baseline of the multi-channel weak current integrating analog-to-digital converter to 0 before the beam irradiation.

5. The beam delivery system according to claim 1 or 4, wherein: The ZYNQ data system is used to mark the start time and end time of each integration period and the position of the target time within the integration period before the beam irradiation, and the target time is any time between the start time and the end time.

6. The beam delivery system according to claim 1, wherein: The beam transmission system further includes a host computer, which is used to send a calculation threshold to all the channels; The front-end multi-channel current integration electronics is also used to calculate the actual position of the beam using the ADC value of the channel when the ADC value corresponding to the channel is greater than the calculation threshold.

7. The beam delivery system according to claim 1, wherein: The ZYNQ data system is also used to determine whether the irradiation point has been replaced; The determining whether the irradiation point has been replaced includes: During the integration period of the multi-channel weak current integration type analog-to-digital converter of the channel, the beam is continuously in the irradiation path of the same irradiation field point, and the irradiation point replacement is completed; If the beam does not continue to be on the irradiation path of the same irradiation point within the integration period of the multi-channel weak current integration type analog-to-digital converter of the channel, the irradiation point is not replaced and terminated.

8. The beam delivery system according to claim 7, wherein: The ZYNQ data system, wherein the beam is not continuously in the same irradiation field point on the irradiation path, comprises: The beam is located on the irradiation path of the first irradiation point at the beginning of the integration period, and is located on the irradiation path from the first irradiation point to the second irradiation point at the end of the integration period; The beam is continuously on an irradiation path from the first irradiation field point to the second irradiation field point; The beam is located on an irradiation path from the first irradiation point to the second irradiation point at the start time of the integration of the period, and is located on an irradiation path of the second irradiation point at the end time of the integration period; The beam is located on the irradiation path of the first irradiation field point at the start time of the integration period, and is located on the irradiation path of the second irradiation field point at the end time of the integration period.

9. The beam delivery system according to claim 6, wherein: The host computer is used to send the calculation threshold to the channel when the numerical baseline of the multi-channel weak current integrating analog-to-digital converter is set to 0.

10. A beam transmission method, comprising: According to whether the irradiation point has been replaced, the actual position of the beam is calculated; Before the irradiation point is replaced, determining the deviation between the actual position of the beam and the ideal position; The beam current is adjusted according to the deviation.

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