A fast tuning system and method for the magnetic field of a transport line magnet in a proton therapy system

Abstract

The application provides a kind of fast regulation system and method of transport line magnet magnetic field in proton therapy system, wherein the regulation system includes dipole magnet, modular power supply, beam transport line control unit, magnetic field regulation power supply and current measuring device;Dipole magnet is equipped with Hall probe;Modular power supply is electrically connected with dipole magnet;Beam transport line control unit is electrically connected with Hall probe and modular power supply respectively;Magnetic field regulation power supply is electrically connected with modular power supply and beam transport line control unit respectively;Current measuring device is electrically connected with modular power supply and magnetic field regulation power supply respectively.The application uses additional current to change the current of magnet power supply, so that the magnet power supply mistakenly believes that the required current has not been reached and adjusts, so that the magnet magnetic field is quickly regulated to the required field value, to solve the problem that when the current is changed, the magnet magnetic field needs to be stabilized before irradiation due to the eddy current effect of the magnet.

Description

Technical Field

[0001] This invention relates to the field of proton therapy technology, and in particular to a system and method for rapidly adjusting the magnetic field of a transport line magnet in a proton therapy system. Background Technology

[0002] In a proton therapy system, a fixed-energy beam emerges from a cyclotron and travels through a transport line to the treatment head to irradiate the patient. Typically, the beam energy is reduced to irradiate from the distal end of the tumor to the proximal end. Correspondingly, the magnetic field and current of the magnet are also dynamically reduced. During irradiation, the magnetic field must be accurate and stable.

[0003] During proton therapy, a diode magnet (hereinafter referred to as "magnet") controls the deflection of the beam, usually by adjusting the current. The current setpoint of the magnet is connected to the required range through a lookup table. Due to the hysteresis characteristics of the magnet, a single current setpoint may correspond to several field values, depending on the magnet's excitation process.

[0004] To ensure the beam current is always at the required position, we must ensure the magnetic field remains constant for a given energy. Therefore, within the set range of the first layer, all magnets are cyclical. This "cyclic" operation involves driving the magnets to their highest current set value (e.g., 360A) to reach the top of the saturation curve (BH). Then, irradiation is typically performed by gradually reducing the beam energy, and the magnet current follows suit, ensuring the trajectory on the saturation excitation curve remains consistent. However, if the irradiation process includes increasing energy or redrawing layers, to achieve the same field value, the magnets need to be cyclical within each set range (re-increasing to the highest current and then decreasing it), resulting in very long layer switching times (several seconds).

[0005] When the energy of the magnet in a proton therapy system is adjusted in the transport line, the corresponding magnetic field and current need to be changed accordingly. Due to the inherent characteristics of the magnet, the eddy current effect causes it to not immediately reach the required magnetic field when the current is changed; irradiation can only proceed after the magnet's magnetic field stabilizes. To address the increased irradiation time caused by the eddy current effect, this invention introduces a Hall effect sensor installed inside the magnet for real-time magnetic field feedback, enabling rapid adjustment of the magnet's magnetic field to the desired value.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the present invention provides a rapid adjustment system, or method, for the magnetic field of a transport line magnet in a proton therapy system. This system introduces a Hall effect probe installed inside the magnet to provide real-time feedback of the magnetic field parameters. Furthermore, by using the current parameters of an additional power supply to change the current parameters of the magnet's power supply, the magnet's power supply is misled into thinking that the required current parameters have not been reached and adjusts its current parameters accordingly. This rapidly adjusts the magnetic field of the magnet to the required value, thus solving the problem that when the current is changed, the eddy current effect of the magnet does not immediately achieve the required magnetic field, requiring waiting for the magnet's magnetic field to stabilize before irradiation.

[0008] This invention provides a rapid magnetic field adjustment system for a transport line magnet in a proton therapy system, comprising a dipole magnet, a modular power supply MPSS, a beam transmission line control unit BLCU, a magnetic field adjustment power supply FRPS, and a current measuring device DCCT. A Hall probe is installed in the dipole magnet; the modular power supply MPSS is electrically connected to the dipole magnet; the beam transmission line control unit BLCU is electrically connected to both the Hall probe and the modular power supply MPSS; the magnetic field adjustment power supply FRPS is electrically connected to both the modular power supply MPSS and the beam transmission line control unit BLCU; and the current measuring device DCCT is electrically connected to both the modular power supply MPSS and the magnetic field adjustment power supply FRPS.

[0009] In one embodiment of the present invention, the beam transmission line control unit (BLCU) sends a reference current I to the modular power supply (MPSS) based on the magnetic field parameter B of the diode magnet measured by the Hall probe. REF Send current set point I to the magnetic field regulating power supply FRPS FR Current setpoint I FR Set as reference current I REF The reverse current, the current measuring device DCCT detects the current set point I FR and reference current I REF The combined current ΔI is fed back to the modular power supply MPSS, which then adjusts the current parameter I output to the diode magnet.

[0010] In one embodiment of the present invention, the Hall probe is arranged inside the diode magnet.

[0011] This invention also provides a method for rapidly adjusting the magnetic field of a transport line magnet in a proton therapy system, comprising:

[0012] Determine the magnetic field parameter B corresponding to the current parameter I in the magnetic field of the magnet based on the excitation curve comparison table;

[0013] When it is necessary to change the magnetic field parameter B and the corresponding current setpoint parameter I, select between the current adjustment mode and the magnetic field adjustment mode.

[0014] The current regulation mode increases the current parameter I of the dipole magnet in the magnetic field to the highest current parameter I. MAX When the magnetic field of the diode reaches its saturation point, the current parameter I is then... MAX The current parameter I corresponds to the desired magnetic field parameter B along the hysteresis curve.

[0015] The magnetic field adjustment mode detects the magnetic field parameter B in the magnetic field of the magnet by using a Hall probe and reads the current parameter I of the dipole magnet. Based on the magnetic field parameter B detected by the Hall probe in real time, the current parameter I of the dipole magnet is dynamically adjusted.

[0016] In one embodiment of the present invention, the current regulation mode is achieved by increasing the current parameter I of the dipole magnet in the magnetic field to the highest current parameter I. MAX When the magnetic field of the diode reaches its saturation point, the current parameter I is then... MAX The steps for descending along the hysteresis curve to the current parameter I corresponding to the desired magnetic field parameter B include:

[0017] The current parameter I of the dipole magnet is increased to the maximum current parameter I using a modular power supply MPSS. MAX ;

[0018] The reference current I corresponding to the required magnetic field parameter B is calculated using the beam transmission line control unit (BLCU). REF and the reference current I REF Send to the modular power supply MPSS;

[0019] The current parameter I of the diode magnet is reduced from the highest current parameter I by a modular power supply MPSS. MAX Reduce to reference current I REF .

[0020] In one embodiment of the present invention, the magnetic field adjustment mode detects the magnetic field parameter B in the magnetic field of the magnet using a Hall probe and reads the current parameter I of the dipole magnet. The step of dynamically adjusting the current parameter I of the dipole magnet based on the magnetic field parameter B detected in real time by the Hall probe includes:

[0021] The magnetic field parameter B of the diode magnet is detected by a Hall probe and fed back to the beam transmission line control unit (BLCU).

[0022] The beam transmission line control unit (BLCU) calculates the current parameter I corresponding to the required magnetic field parameter B and converts the current parameter I into a current setpoint I. FR The signal is sent to the magnetic field regulating power supply FRPS and converted into a reference current I. REF Send to the modular power supply MPSS;

[0023] The current set point I is detected by a DCCT current measuring device. FR and reference current IREF The combined current ΔI enables the modular power supply MPSS to adjust the current parameter I output to the diode magnet based on the combined current ΔI.

[0024] In one embodiment of the present invention, the magnetic field parameter B includes a first magnetic field B. A Second magnetic field B B First magnetic field B A Greater than the second magnetic field B B The current parameter I includes the first current I0. A Second current I B First current I A Greater than the second current I B Current setpoint I FR It also includes the current setpoint I FRA Current setpoint I FRA Greater than 0.

[0025] In one embodiment of the present invention, when the magnetic field parameter B of the diode magnet changes from the first magnetic field B... A Adjust to the second magnetic field B B hour;

[0026] Current parameter I from the first current I A Reduce to the second current I B The following, and regarding the second current I B Fluctuating up and down, and the current parameter I is related to the second current I. B The fluctuating value decreases to zero over time;

[0027] Current set point I FR The current rises from zero and fluctuates around zero, and the current setpoint I... FR It returns to zero over time.

[0028] In one embodiment of the present invention, when the magnetic field parameter B of the diode magnet changes from the second magnetic field B... B Adjust to the first magnetic field B A And when using the magnetic field adjustment mode;

[0029] Current parameter I from the second current I B Increase to the first current I A The above, and regarding the first current I A Fluctuating up and down, and the current parameter I is related to the first current I. A The fluctuating value decreases to zero over time;

[0030] Current set point I FR From zero value to current set point I FRA The above, and regarding the current set point I FRA Fluctuations up and down, and current set point I FRRegarding current set point I FRA The fluctuating value decreases to zero over time.

[0031] In one embodiment of the present invention, the magnetic field parameter B further includes a third magnetic field B. C The third magnetic field B C Less than the first magnetic field B A And greater than the second magnetic field B B The current parameter I also includes a third current I. C The third current I C Less than the first current I A And greater than the second current I B ;

[0032] When the magnetic field parameter B of the dipole magnet changes from the second magnetic field B B Adjust to the first magnetic field B A And when the magnetic field adjustment mode is not used;

[0033] Magnetic field parameter B from the second magnetic field B B Raise to the third magnetic field B C ;

[0034] Current parameter I from the second current I B Increase to the third current I C .

[0035] The beneficial effects of this invention are as follows: This invention provides a rapid adjustment system and method for the magnetic field of a transport line magnet in a proton therapy system. By using an additional magnetic field adjustment power supply to "trick" the modular power supply of the magnet, the adjustment system mistakenly believes that the required current parameter has not been reached and automatically and rapidly adjusts the current parameter of the modular power supply for the magnet. The adjustment system automatically amplifies the adjustment value according to the gain of the current parameter, so that the current parameter of the magnet quickly reaches the current parameter corresponding to the required magnetic field value, reducing the time delay caused by the eddy current effect and shortening the irradiation time.

[0036] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0038] Figure 1 This is a schematic diagram of the magnet magnetic field rapid adjustment system of the present invention;

[0039] Figure 2 This is a schematic diagram of the magnetic field current variation curve of the magnet in this invention;

[0040] Figure 3 This is a flowchart of the method for rapidly adjusting the magnetic field of a magnet according to the present invention;

[0041] Figure 4 This is a schematic diagram illustrating the effect of the rising and falling current eddy current on the magnetic field changes in this invention.

[0042] Figure 5 This is a schematic diagram of parameter variation curves in magnetic field regulation mode and current regulation mode in one embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of parameter variation curves in magnetic field regulation mode and current regulation mode in one embodiment of the present invention.

[0044] In the diagram: 1. Dipole magnet; 2. Hall effect probe; 3. Modular power supply MPSS; 4. Beam transmission line control unit BLCU; 5. Magnetic field conditioning power supply FRPS; 6. Current measurement device DCCT. Detailed Implementation

[0045] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of the present invention is for describing specific implementation schemes and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0046] Please see Figures 1 to 6It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0047] Please see Figure 1 This invention provides a rapid magnetic field adjustment system for a transport line magnet in a proton therapy system, comprising a dipole magnet, a modular power supply MPSS, a beam transmission line control unit BLCU, a magnetic field adjustment power supply FRPS, and a current measuring device DCCT. A Hall probe is installed in the dipole magnet; the modular power supply MPSS is electrically connected to the dipole magnet; the beam transmission line control unit BLCU is electrically connected to both the Hall probe and the modular power supply MPSS; the magnetic field adjustment power supply FRPS is electrically connected to both the modular power supply MPSS and the beam transmission line control unit BLCU; and the current measuring device DCCT is electrically connected to both the modular power supply MPSS and the magnetic field adjustment power supply FRPS.

[0048] Furthermore, the beam transmission line control unit (BLCU) sends a reference current I to the modular power supply (MPSS) based on the magnetic field parameter B of the diode magnet measured by the Hall probe. REF Send current set point I to the magnetic field regulating power supply FRPS FR Current setpoint I FR Set as reference current I REF The reverse current, the current measuring device DCCT detects the current set point I FR and reference current I REF The combined current ΔI is fed back to the modular power supply MPSS, which then adjusts the current parameter I output to the diode magnet. The Hall probe is positioned inside the diode magnet.

[0049] In a proton therapy system, a fixed-energy beam exits from a cyclotron, travels through a transport line to the treatment head, and irradiates the patient. Typically, the beam energy is reduced, irradiating from the distal end of the tumor to the proximal end. Correspondingly, the magnetic field and current of the magnet are also dynamically reduced. Accurate and stable magnetic field control is required during irradiation. It should be noted that in this embodiment of the invention, the magnet refers to a dipolar magnet, which plays a role in forming and controlling the magnetic field of the proton therapy beam.

[0050] like Figure 2 During normal magnet irradiation, the current decreases along curve II to B. If increased energy is needed, simply increasing the current will cause the current to decrease along curve B to C. Decreasing the current afterwards results in a new excitation curve that no longer follows curve II. This leads to one current corresponding to multiple magnetic fields, introducing uncertainty into the irradiation process. If increased energy or repeated irradiation is required, the magnet current needs to be increased. The usual practice is to first raise the magnet current to its maximum, reaching the magnet's magnetic field saturation point, and then decrease it along the hysteresis curve to the required current for irradiation. This process is complex, takes time, and results in a longer irradiation time.

[0051] Therefore, in this embodiment of the invention, in order to achieve rapid magnetic field adjustment, a Hall probe is introduced and installed inside the magnet to detect the magnitude of the magnet's magnetic field in real time. Instead of adjusting the magnetic field based on the excitation curve table of current and magnetic field, the current value of the magnet is dynamically adjusted by reading the real-time magnetic field value from the Hall probe.

[0052] A Hall probe is placed in the magnetic field generated by a diode magnet, and the detected magnetic field parameter B is fed back to the Beamline Control Unit (BLCU). The BLCU calculates the required change in the corresponding current parameter I based on the change in the magnetic field parameter B to be adjusted, and uses the corresponding current parameter I as the reference current I. REF The signal is sent to the Modular Power Supply System (MPSS) and the corresponding current parameter I is sent as an adjustment signal to the Field Regulating Power Supply (FRPS).

[0053] For example, during the initial irradiation, a reference current I is directly sent to the modular power supply MPSS. REF The current parameter I is the output current to the diode magnet.

[0054] When it is necessary to change the magnetic field parameter B, the adjustment signal sent to the magnetic field conditioning power supply FRPS is used to generate the current setpoint I. FR and make the current set point I FR Set as reference current I REF The reverse current is calculated during this process using a current measuring device (Direct Current Transformer DCCT) to determine the current setpoint I. FR and reference current I REFThe combined current ΔI is fed back to the modular power supply MPSS, and the current parameter I output by the modular power supply MPSS to the diode magnet is adjusted according to the combined current ΔI.

[0055] It should be noted that the current parameter I of the dipole magnet is provided solely by the modular power supply MPSS and is controlled by the modular power supply MPSS. The current setpoint I provided by the magnetic field conditioning power supply FRPS is... FR It is the reverse current of the current parameter I output from the modular power supply MPSS to the diode magnet (at this time, the current parameter I output from the modular power supply MPSS to the diode magnet refers to the reference current I). REF This causes the current parameter I from the output to the diode magnet of the modular power supply MPSS to be less than the required current parameter I, thus prompting the modular power supply MPSS to quickly adjust the current parameter I from the output to the diode magnet.

[0056] Theoretically, the modular power supply MPSS powers the diode magnet, and the current parameter I can only be adjusted after the magnetic field parameter B has been detected. However, by adding a magnetic field regulating power supply FRPS, a reverse current is provided to the modular power supply MPSS, misleading the current measuring device DCCT to report that the current parameter I output by the modular power supply MPSS to the diode magnet has not reached the required value. In this case, the modular power supply MPSS can immediately respond and quickly adjust the current parameter I output to the diode magnet.

[0057] For details on the adjustment process, please refer to the appendix. Figure 1 Feedback is sent to the beam transmission line control unit (BLCU) via a Hall effect probe mounted on a diode magnet. The BLCU then calculates the required reference current I. REF The signal is sent to the modular power supply MPSS, which powers the dipole magnet. When an energy change is needed (i.e., when the current to the dipole magnet needs to be changed to alter the magnetic field), the beam transmission line control unit (BLCU) sends an adjustment signal to the magnetic field conditioning power supply (FRPS). The FRPS then generates a current setpoint I based on the adjustment signal. FR The DCCT current measuring device simultaneously detects the current set point I of the FRPS magnetic field regulating power supply. FR and the reference current I of the modular power supply MPSS REF The combined current ΔI is fed back to the modular power supply MPSS, causing the magnetic field regulating power supply MPSS to mistakenly believe that the current parameter I output to the diode magnet has not reached the required value, thereby adjusting the current parameter I output to the diode magnet.

[0058] This invention employs a signal from the FRPS (Focus Regulating Power Supply) to "deceive" the MPSS (Magnetic Field Regulating Power Supply), causing the MPSS to mistakenly believe that the current parameter I of the diode has not reached the required value, thus rapidly adjusting the magnitude of the current parameter I. The actual current setpoint I of the FRPS is... FR It does not act on the dipolar magnet.

[0059] Please see Figures 2 to 5 The present invention also provides a method for rapid adjustment of the magnetic field of a transport line magnet in a proton therapy system, comprising:

[0060] Determine the magnetic field parameter B corresponding to the current parameter I in the magnetic field of the magnet based on the excitation curve comparison table;

[0061] When it is necessary to change the magnetic field parameter B and the corresponding current setpoint parameter I, select between the current adjustment mode and the magnetic field adjustment mode.

[0062] The current regulation mode increases the current parameter I of the dipole magnet in the magnetic field to the highest current parameter I. MAX When the magnetic field of the diode reaches its saturation point, the current parameter I is then... MAX The current parameter I corresponds to the desired magnetic field parameter B along the hysteresis curve.

[0063] The magnetic field adjustment mode detects the magnetic field parameter B in the magnetic field of the magnet by using a Hall probe and reads the current parameter I of the dipole magnet. Based on the magnetic field parameter B detected by the Hall probe in real time, the current parameter I of the dipole magnet is dynamically adjusted.

[0064] Please see the appendix Figure 4 When the current in a dipole magnet increases or decreases, the magnetic field always lags behind the current to reach equilibrium due to the eddy current effect; this delay is called the settling time. Therefore, when adjusting the magnetic field parameter B using the dipole magnet, it is necessary to restore the magnetic field parameter B formed by the dipole magnet to its maximum saturation point. Specifically, in this embodiment, please refer to the appendix. Figure 2 The normal irradiation process of the diode magnet descends along curve II to point B. If it involves increasing the magnetic field energy or repeated irradiation, it is necessary to increase the current of the diode magnet. The usual practice is to first increase the current parameter I of the diode magnet to the highest current parameter I. MAX The magnetic field reaches the saturation point of the dipole magnet, and then descends along the hysteresis curve to the magnetic field parameter B corresponding to the required current parameter I for irradiation. In this embodiment of the invention, the magnet, i.e., the dipole magnet, serves as the magnetic field for forming and controlling the beam current in the proton therapy system.

[0065] Specifically, the current regulation mode increases the current parameter I of the dipole magnet in the magnetic field to the highest current parameter I. MAXWhen the magnetic field of the diode reaches its saturation point, the current parameter I is then... MAX The steps for descending along the hysteresis curve to the current parameter I corresponding to the desired magnetic field parameter B include:

[0066] The current parameter I of the dipole magnet is increased to the maximum current parameter I using a modular power supply MPSS. MAX ;

[0067] The reference current I corresponding to the required magnetic field parameter B is calculated using the beam transmission line control unit (BLCU). REF and the reference current I REF Send to the modular power supply MPSS;

[0068] The current parameter I of the diode magnet is reduced from the highest current parameter I by a modular power supply MPSS. MAX Reduce to reference current I REF .

[0069] like Figure 2 During normal magnet irradiation, the current decreases along curve II to B. If increased energy is needed, simply increasing the current will cause the current to decrease along curve B to C. Decreasing the current afterwards results in a new excitation curve that no longer follows curve II. This leads to one current corresponding to multiple magnetic fields, introducing uncertainty into the irradiation process. If increased energy or repeated irradiation is required, the magnet current needs to be increased. The usual practice is to first raise the magnet current to its maximum, reaching the magnet's magnetic field saturation point, and then decrease it along the hysteresis curve to the required current for irradiation. This process is complex and time-consuming, resulting in a longer irradiation time. This mode is called current regulation.

[0070] Specifically, the magnetic field adjustment mode uses a Hall probe to detect the magnetic field parameter B in the magnetic field of the magnet and reads the current parameter I of the dipole magnet. Based on the real-time detection of the magnetic field parameter B by the Hall probe, the current parameter I of the dipole magnet is dynamically adjusted. The steps include:

[0071] The magnetic field parameter B of the diode magnet is detected by a Hall probe and fed back to the beam transmission line control unit (BLCU).

[0072] The beam transmission line control unit (BLCU) calculates the current parameter I corresponding to the required magnetic field parameter B and converts the current parameter I into a current setpoint I. FR The signal is sent to the magnetic field regulating power supply FRPS and converted into a reference current I. REF Send to the modular power supply MPSS;

[0073] The current set point I is detected by a DCCT current measuring device. FR and reference current I REFThe combined current ΔI enables the modular power supply MPSS to adjust the current parameter I output to the diode magnet based on the combined current ΔI.

[0074] To achieve rapid magnetic field regulation, a Hall probe is installed inside the magnet to detect the magnitude of the magnetic field in real time. Instead of relying on a table of excitation curves for current and magnetic field to adjust the magnetic field, the current value of the magnet is dynamically adjusted based on the real-time magnetic field value read from the Hall probe. This mode is called field regulation.

[0075] During the use of the magnetic field conditioning mode, feedback is sent to the beam transmission line control unit (BLCU) via a Hall effect probe mounted on a diode magnet. The BLCU sends a conditioning signal to the magnetic field conditioning power supply (FRPS), which then generates a current setpoint I based on the signal. FR The DCCT current measuring device can simultaneously detect the current set point I of the magnetic field regulating power supply FRPS. FR and the reference current I of the magnetic field regulating power supply MPSS REF The combined current ΔI is generated by the magnetic field regulating power supply FRPS to "deceive" the magnetic field regulating power supply MPSS, making the magnetic field regulating power supply MPSS mistakenly believe that the current parameter I of the diode magnet has not reached the required value, so as to quickly adjust the magnitude of the current parameter I of the diode magnet.

[0076] Please see Figure 5 In one embodiment, the magnetic field parameter B includes a first magnetic field B. A Second magnetic field B B First magnetic field B A Greater than the second magnetic field B B The current parameter I includes the first current I0. A Second current I B First current I A Greater than the second current I B Current setpoint I FR It also includes the current setpoint I FRA Current setpoint I FRA Greater than 0.

[0077] Furthermore, when the magnetic field parameter B of the diode magnet changes from the first magnetic field B... A Adjust to the second magnetic field B B At that time; the current parameter I is from the first current I A Reduce to the second current I B The following, and regarding the second current I B Fluctuating up and down, and the current parameter I is related to the second current I. B The fluctuating value decreases to zero over time; current setpoint IFR The current rises from zero and fluctuates around zero, and the current setpoint I... FR It returns to zero over time.

[0078] Similarly, when the magnetic field parameter B of the dipolar magnet changes from the second magnetic field B... B Adjust to the first magnetic field B A Furthermore, when using the magnetic field regulation mode; the current parameter I changes from the second current I B Increase to the first current I A The above, and regarding the first current I A Fluctuating up and down, and the current parameter I is related to the first current I. A The fluctuating value decreases to zero over time; current setpoint I FR From zero value to current set point I FRA The above, and regarding the current set point I FRA Fluctuations up and down, and current set point I FR Regarding current set point I FRA The fluctuating value decreases to zero over time.

[0079] Furthermore, the magnetic field parameter B also includes a third magnetic field B. C The third magnetic field B C Less than the first magnetic field B A And greater than the second magnetic field B B The current parameter I also includes a third current I. C The third current I C Less than the first current I A And greater than the second current I B When the magnetic field parameter B of the diode magnet changes from the second magnetic field B B Adjust to the first magnetic field B A And when the magnetic field adjustment mode is not used; the magnetic field parameter B is from the second magnetic field B B Raise to the third magnetic field B C The current parameter I is derived from the second current I. B Increase to the third current I C .

[0080] Please see the appendix Figure 5 The diagrams show examples of both decreasing and increasing current modes. When using the magnetic field regulation mode, the magnetic field regulation power supply FRPS will feed back a current signal to the current measuring device DCCT, indicating the current setpoint I. FR If the modular power supply MPSS determines that the required current parameter I has not been met, the modular power supply MPSS will immediately adjust the current parameter I of the magnet. By rapidly adjusting the magnetic field of the magnet to the required magnetic field parameter I in real time, the magnetic field delay caused by the eddy current effect is shortened.

[0081] Please see the appendix Figure 5 The portion of the function curve where both solid and dashed lines coexist: During the adjustment of magnetic field parameter B, the current setpoint I provided by the magnetic field regulating power supply FRPS... FR The modular power supply MPSS provides a current parameter I to the magnet that exceeds the current parameter I corresponding to the magnetic field parameter B that needs to be adjusted, so that the current parameter I is obtained from the first current I. A Reduce to the second current I B The following, or the current parameter I is made to change from the second current I B Increase to the first current I A At this point, due to hysteresis, the change in magnetic field parameter B is still within the range of the first magnetic field B. A Adjust to the second magnetic field B B Within the range, or the change in magnetic field parameter B is still within the range of the second magnetic field B. B Adjust to the first magnetic field B A Within the specified range, and as it approaches the desired magnetic field parameter B, the control current setpoint I... FR The current parameter I is restored to the target value. This shortens the magnetic field delay caused by the eddy current effect.

[0082] Please see the appendix Figure 5 The relationship between the time-varying current parameter I and the time-varying magnetic field parameter B can be understood as a derivative relationship. The change in current parameter I reflects the incremental change in magnetic field parameter B. By observing the correspondence between the solid and dashed lines in the function graph, it can be understood that by increasing the change in current parameter I, the incremental change in magnetic field parameter B can be satisfied in advance.

[0083] It should be noted that when increasing the magnetic field parameter B of the magnet, the magnetic field adjustment mode can avoid the situation where the magnetic field parameter increment is insufficient due to hysteresis. Therefore, unlike the current adjustment mode, it is not necessary to raise the magnet current back to the highest saturation point of the magnetic field and then lower it along the hysteresis curve to the required current for irradiation.

[0084] Specifically, in current regulation mode, the interlayer switching time is typically 1 second when the energy is reduced (current is decreased), and about 6 seconds when the energy is increased (the magnet needs to first increase the current to the saturation point and then decrease the current). In magnetic field regulation mode, the circulating magnet is no longer needed, and the interlayer switching time is about 1.2-1.3 seconds, reducing beam stabilization delay and interlayer switching time.

[0085] like Figure 5As shown, in one embodiment of the present invention, when the current drops from 174.367A to 171.129A, the magnet without magnetic field adjustment needs 2.56s to reach the 2Gs stable line, while the magnet with magnetic field adjustment only needs 0.28s.

[0086] In practice, achieving the field setpoint is thanks to an additional magnetic field conditioning power supply (FRPS). A Hall probe, with a magnet inserted to generate a magnetic field, provides real-time feedback of the magnetic field parameter B to the beam transmission line control unit (BLCU).

[0087] The beam transmission line control unit (BLCU) compares the received magnetic field target and sends a setpoint proportional to the difference between the magnetic field setpoint and the feedback to the magnetic field conditioning power supply (FRPS). This setpoint is used to close the loop and regulate the current measurement device (DCCT) of the modular power supply (MPSS). The DCCT measures the combined current of the modular power supply (MPSS) and the magnetic field conditioning power supply (FRPS).

[0088] The modular power supply MPSS continuously adjusts its setpoint based on feedback from the current measuring device DCCT, thus performing internal regulation. Instead of directly adjusting the MPSS's current parameter I setpoint based on field feedback, the current parameter I is "tricked" into being adjusted by the DCCT. This is because the MPSS can only accept a new setpoint when the previous one is reached, a process that is too slow to meet the target field adjustment time. Therefore, using the MPSS's internal regulation loop is a workaround to overcome this limitation.

[0089] In summary, the present invention provides a method for rapid adjustment of the magnetic field of a transport line magnet in a proton therapy system. By using an additional magnetic field adjustment power supply (FRPS) to "trick" the modular power supply (MPSS) of the magnet into thinking that the required current parameter I has not been reached, the modular power supply (MPSS) automatically and rapidly adjusts the current parameter I of the magnet power supply. This allows the modular power supply (MPSS) to automatically amplify the adjustment value according to the gain of the current parameter I, so that the current parameter I of the magnet quickly reaches the current parameter I corresponding to the required magnetic field parameter B, reducing the time delay caused by the eddy current effect and shortening the irradiation time.

[0090] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A rapid adjustment system for the magnetic field of a transport line magnet in a proton therapy system, characterized in that, include: A binary magnet, wherein a Hall probe is installed in the binary magnet; A modular power supply MPSS, wherein the modular power supply MPSS is electrically connected to the diode magnet; A beam transmission line control unit (BLCU) is electrically connected to the Hall probe and the modular power supply (MPSS). A magnetic field conditioning power supply FRPS is electrically connected to the modular power supply MPSS and the beam transmission line control unit BLCU, respectively. A current measuring device DCCT is electrically connected to the modular power supply MPSS and the magnetic field conditioning power supply FRPS. The beam transmission line control unit (BLCU) sends a reference current I to the modular power supply (MPSS) based on the magnetic field parameter B of the diode magnet measured by the Hall probe. REF Send current set point I to the magnetic field regulating power supply FRPS FR The current setting point I FR Set as the reference current I REF The reverse current, the current measuring device DCCT detects the current set point I. FR and the reference current I REF The combined current ΔI is fed back to the modular power supply MPSS, so that the modular power supply MPSS adjusts the current parameter I output to the diode magnet.

2. The system according to claim 1, characterized in that, The Hall probe is positioned inside the diode magnet.

3. A method for rapidly adjusting the magnetic field of a transport line magnet in a proton therapy system, characterized in that, include: Determine the magnetic field parameter B corresponding to the current parameter I in the magnetic field of the magnet based on the excitation curve comparison table; When it is necessary to change the magnetic field parameter B and adjust the current parameter I accordingly, a selection can be made between the current adjustment mode and the magnetic field adjustment mode. The current regulation mode increases the current parameter I of the dipole magnet in the magnetic field to the highest current parameter I. MAX When the magnetic field saturation point of the diode magnet is reached, the current parameter I is then... MAX The current parameter I corresponding to the desired magnetic field parameter B is descended along the hysteresis curve; The magnetic field adjustment mode detects the magnetic field parameter B in the magnetic field of the magnet by a Hall probe and reads the current parameter I of the diode magnet. Based on the magnetic field parameter B detected by the Hall probe in real time, the current parameter I of the diode magnet is dynamically adjusted. The current regulation mode increases the current parameter I of the dipole magnet in the magnetic field to the highest current parameter I. MAX When the magnetic field saturation point of the diode magnet is reached, the current parameter I is then... MAX The step of descending along the hysteresis curve to the current parameter I corresponding to the desired magnetic field parameter B includes: The current parameter I of the dipole magnet is increased to the maximum current parameter I by using a modular power supply MPSS. MAX ; The reference current I corresponding to the required magnetic field parameter B is calculated using the beam transmission line control unit (BLCU). REF and the reference current I REF Send to the modular power supply MPSS; The modular power supply MPSS reduces the current parameter I of the diode magnet from the highest current parameter I. MAX Reduced to the reference current I REF ; The magnetic field adjustment mode detects the magnetic field parameter B in the magnetic field of the magnet using a Hall probe and reads the current parameter I of the diode magnet. The step of dynamically adjusting the current parameter I of the diode magnet based on the real-time detection of the magnetic field parameter B by the Hall probe includes: The magnetic field parameter B of the diode magnet is detected by a Hall probe and fed back to the beam transmission line control unit (BLCU). The beam transmission line control unit (BLCU) calculates the current parameter I corresponding to the required magnetic field parameter B and converts the current parameter I into a current setpoint I. FR The signal is sent to the magnetic field regulating power supply FRPS and converted into a reference current I. REF Send to the modular power supply MPSS; The current setpoint IFR and the reference current I are detected by a current measuring device DCCT. REF The combined current ΔI causes the modular power supply MPSS to adjust the current parameter I output to the diode magnet based on the combined current ΔI.

4. The method according to claim 3, characterized in that, The magnetic field parameter B includes the first magnetic field B. A Second magnetic field B B The first magnetic field B A Greater than the second magnetic field B B The current parameter I includes a first current I. A Second current I B The first current I A Greater than the second current I B The current setting point I FR It also includes the current setpoint I FRA The current setting point I FRA Greater than 0.

5. The method according to claim 4, characterized in that, When the magnetic field parameter B of the dipole magnet changes from the first magnetic field B A Adjust to the second magnetic field B B hour; The current parameter I is derived from the first current I. A Reduce to the second current I B The following, and regarding the second current I B Fluctuating up and down, and the current parameter I is related to the second current I. B The fluctuating value decreases to zero over time; The current setting point I FR The current rises from zero and fluctuates around zero, and the current set point I FR It returns to zero over time.

6. The method according to claim 4, characterized in that, When the magnetic field parameter B of the dipole magnet changes from the second magnetic field B B Adjust to the first magnetic field B A And when the magnetic field adjustment mode is used; The current parameter I is derived from the second current I. B Increase to the first current I A The above, and regarding the first current I A Fluctuating up and down, and the current parameter I is related to the first current I. A The fluctuating value decreases to zero over time; The current setting point I FR From zero value to the current set point I FRA The above, and regarding the current setting point I FRA Fluctuating up and down, and the current setting point I FR Regarding the current setting point I FRA The fluctuating value decreases to zero over time.

7. The method according to claim 4, characterized in that, The magnetic field parameter B also includes a third magnetic field B. C The third magnetic field B C Less than the first magnetic field B A And greater than the second magnetic field B B The current parameter I also includes a third current I. C The third current I C Less than the first current I A And greater than the second current I B ; When the magnetic field parameter B of the dipole magnet changes from the second magnetic field B B Adjust to the first magnetic field B A And when the magnetic field adjustment mode is not used; The magnetic field parameter B is derived from the second magnetic field B. B Raise to the third magnetic field B C ; The current parameter I is derived from the second current I. B Increase to the third current I C .

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