Precision positioning method of proton motion, treatment head, device, equipment and medium

Abstract

The invention discloses a precise positioning method for proton motion, a treatment head, a device, equipment and a medium, and the method comprises the steps: constructing a space geometric model according to a deflection motion track of a proton moving to a preset target position under the action of a scanning magnetic field, and carrying out the space geometric analysis according to the space geometric model; according to the deflection radius and the proton energy, obtaining the target magnetic field intensity of the scanning magnetic field required by the proton to move to a preset target position, obtaining the actual magnetic field intensity of the scanning magnetic field, and according to the target magnetic field intensity and the actual magnetic field intensity, obtaining the target magnetic field intensity of the scanning magnetic field. The target current of a scanning magnet corresponding to the scanning magnetic field is obtained, and the deflection movement track of the proton in the scanning magnetic field is controlled according to the target current, so that precise positioning of proton movement is achieved. According to the method, the hysteresis phenomenon influence caused by magnet eddy current is reduced, and the efficiency and safety of irradiation treatment on a patient are effectively guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of proton therapy, and in particular relates to a method, a treatment head, a device, equipment and a medium for accurately positioning proton movement. Background Art

[0002] The pencil-beam spot scanning treatment head primarily consists of an X-scanning magnet, a Y-scanning magnet, a control system, a vacuum chamber, a primary dose ionization chamber, and a position ionization chamber. The beam-matching system in the treatment head primarily converts the accelerator beam into a therapeutic beam and accurately directs it to the target tissue. The key to the entire beam-matching system is precisely controlling the uniform scanning magnetic field to deliver protons to the target tumor location, generating a Bragg peak effect and rapidly releasing energy to destroy tumor cells. Therefore, the X- and Y-scanning magnets, which generate the uniform scanning magnetic field, are the core components of the treatment head beam-matching system.

[0003] The precise control of the scanning magnetic field in the existing technology is mainly composed of an XY direction scanning magnet current control unit, a uniform scanning magnetic field strength B and a scanning magnet current I control unit. Its main function is to determine the proton energy according to the depth of the tumor tissue stratification, and to control the deflection of the proton's trajectory in the scanning magnetic field by precisely adjusting the XY scanning magnet current I, so that the proton can accurately run to the Spot position point on the tissue layer isocenter plane Zn. Summary of the Invention

[0004] The purpose of the present invention is to provide a precise positioning method, treatment head, device, equipment and medium for proton movement. It innovatively proposes to combine spatial geometric analysis with the physical properties of protons and electromagnetism, and apply it to the deflection movement of protons in an XY scanning magnetic field, thereby solving the technical problems in the existing technology of complex current regulation mode process and hysteresis phenomenon caused by eddy current of magnets.

[0005] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] The present invention provides a method for accurately positioning proton motion, which is applied to a pencil-shaped beam spot scanning treatment head. The method comprises:

[0007] constructing a spatial geometric model based on the deflection motion trajectory of the protons moving to a preset target position under the action of the scanning magnetic field, and performing spatial geometric analysis based on the spatial geometric model to obtain the deflection radius of the protons in the scanning magnetic field;

[0008] Obtaining a target magnetic field strength of the scanning magnetic field required for the proton to move to a preset target position according to the deflection radius and the proton energy;

[0009] Obtaining the actual magnetic field strength of the scanning magnetic field;

[0010] According to the target magnetic field strength and the actual magnetic field strength, to obtain the target current of the scanning magnet corresponding to the scanning magnetic field;

[0011] Control the deflection motion trajectory of the proton in the scanning magnetic field according to the target current, so as to achieve the precise positioning of the proton motion.

[0012] In an embodiment of the present invention, the scanning magnetic field includes a first-direction scanning magnetic field and a second-direction scanning magnetic field, wherein the first direction and the second direction are perpendicular to each other.

[0013] In an embodiment of the present invention, the geometric analysis according to the spatial geometric model to obtain the deflection radius of the proton in the scanning magnetic field includes:

[0014] Taking the first direction as the X-axis, the second direction as the Y-axis, the central axis of the proton beam emitted from the accelerator as the Z-axis, and the incident position of the proton entering the first-direction scanning magnetic field as the origin, to establish a three-dimensional space coordinate system;

[0015] Obtain the distance of the first-direction scanning magnetic field on the Z-axis;

[0016] Obtain the coordinate value of the preset target position on the Z-axis;

[0017] Obtain the coordinate value of the preset target position on the X-axis;

[0018] Perform geometric calculations according to the distance of the first-direction scanning magnetic field on the Z-axis, the coordinate value of the preset target position on the Z-axis, and the coordinate value of the preset target position on the X-axis, so as to obtain the deflection radius of the proton in the first-direction scanning magnetic field.

[0019] In an embodiment of the present invention, the obtaining of the target magnetic field strength of the scanning magnetic field according to the deflection radius and the proton energy includes:

[0020] Obtain the magnetic rigidity constant of the proton according to the proton energy;

[0021] Calculate the target magnetic field strength of the scanning magnetic field required for the proton to move to the preset target position according to the magnetic rigidity constant and the deflection radius.

[0022] In an embodiment of the present invention, the calculation formula of the target magnetic field strength of the scanning magnetic field is:

[0023]

[0024] Wherein, B is the target magnetic field strength, T is the proton energy, E0 is the proton rest energy, c is the speed of light, and r is the deflection radius of the proton in the scanning magnetic field.

[0025] In one embodiment of the present invention, the obtaining of the actual magnetic field strength of the scanning magnetic field includes:

[0026] The actual magnetic field strength of the scanning magnetic field is detected in real time by Hall probes respectively installed at the outlet and the inlet of the scanning magnetic field.

[0027] In one embodiment of the present invention, the obtaining of the target current of the scanning magnet corresponding to the scanning magnetic field according to the target magnetic field strength and the actual magnetic field strength includes:

[0028] Obtaining the scanning magnetic field strength deviation between the target magnetic field strength of the scanning magnetic field and the actual magnetic field strength of the scanning magnetic field;

[0029] According to the scanning magnetic field strength deviation, the target current of the scanning magnet corresponding to the scanning magnetic field is obtained through PID operation.

[0030] Based on the same inventive concept, another embodiment of the present invention further provides a pencil beam spot scanning treatment head, and the pencil beam spot scanning treatment head uses the precise positioning method of proton movement as described in any one of the above to control proton movement.

[0031] Based on the same inventive concept, another embodiment of the present invention further provides a precise positioning device for proton movement, including:

[0032] A deflection radius acquisition module, configured to construct a spatial geometric model according to the deflection movement trajectory of the proton moving to a preset target position under the action of the scanning magnetic field, and perform spatial geometric analysis according to the spatial geometric model to obtain the deflection radius of the proton in the scanning magnetic field;

[0033] A target magnetic field strength acquisition module, configured to obtain the target magnetic field strength of the scanning magnetic field required for the proton to move to a preset target position according to the deflection radius and the proton energy;

[0034] A target current acquisition module, configured to obtain the actual magnetic field strength of the scanning magnetic field, and obtain the target current of the scanning magnet corresponding to the scanning magnetic field according to the target magnetic field strength and the actual magnetic field strength;

[0035] A movement control module, which controls the deflection movement trajectory of the proton in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement.

[0036] Based on the same inventive concept, another embodiment of the present invention further provides an electronic device, and the electronic device includes:

[0037] One or more processors;

[0038] A storage device for storing one or more programs, which, when executed by the one or more processors, cause the electronic device to implement the precise positioning method of proton movement as described in any one of the above.

[0039] Based on the same inventive concept, another embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor of a computer, the computer is caused to execute the precise positioning method of proton movement as described in any one of the above.

[0040] As described above, a precise positioning method of proton movement provided by the present invention has the following beneficial effects: By performing mathematical calculations on the deflection movement model of protons in the scanning magnetic field, and installing Hall probes at the outlet and inlet of the scanning magnetic field and combining PID real-time operation to adjust the target current of the scanning magnet, it effectively ensures that protons deflect in a circular motion through the scanning magnetic field and move to a preset target position on the isocenter plane of the tumor tissue layer, and releases particle energy to destroy and eliminate tumor cells with precision, reduces the influence of magnetic hysteresis caused by magnet eddy currents, and more effectively guarantees the efficiency and safety of irradiating patients. Of course, any product implementing the present invention does not necessarily need to achieve all the above-mentioned advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0042] Figure 1 It is a schematic flowchart of a precise positioning method of proton movement provided by an exemplary embodiment of the present application.

[0043] Figure 2 It is a schematic diagram of a model of protons deflected by an XY scanning magnetic field provided by an exemplary embodiment of the present application.

[0044] Figure 3 It is a geometric analysis diagram of the deflection movement trajectory of protons in the first-direction scanning magnetic field provided by an exemplary embodiment of the present application.

[0045] Figure 4 It is a curve graph of the change in the current of the scanning magnet under the current adjustment mode provided by an exemplary embodiment of the present application.

[0046] Figure 5 The curve graph showing the influence of the lifting current eddy current of the scanning magnet provided by an exemplary embodiment of the present application.

[0047] Figure 6 The curve graph of the decreasing current change of the scanning magnet under the magnetic field regulation mode provided by an exemplary embodiment of the present application.

[0048] Figure 7 The curve graph of the increasing current change of the scanning magnet under the magnetic field regulation mode provided by an exemplary embodiment of the present application.

[0049] Figure 8 The structural schematic diagram of a precise positioning device for proton movement provided by another exemplary embodiment of the present application.

[0050] Figure 9 The structural schematic diagram of an electronic device provided by another exemplary embodiment of the present application. Detailed implementation manners

[0051] The following uses specific specific examples to illustrate the implementation manners 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 implementation manners. 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, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0052] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0053] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0054] Pencil beam spot scanning technology, also known as point scanning of proton beam or pencil beam scanning, is a high-precision proton therapy method. During the treatment process, the treatment head is responsible for guiding and precisely controlling the proton beam, enabling it to be "sprayed" layer by layer on the tumor tissue, thereby achieving precise targeting of the tumor lesion. This technology can significantly improve the tumor control rate while reducing radiation damage to surrounding normal tissues.

[0055] Inside the treatment head of pencil beam spot scanning, there are advanced positioning systems and scanning magnets, which can precisely control the direction and intensity of the proton beam, ensuring that the proton beam can accurately irradiate the tumor lesion. Through the spot scanning method, the treatment head can divide the proton beam into multiple small spots and scan the tumor layer by layer according to the predetermined treatment plan. This method can achieve three-dimensional precise treatment of the tumor and improve the treatment effect. Due to the energy release characteristics of the proton beam (i.e., the Bragg peak), the treatment head can ensure that the proton beam releases the maximum energy inside the tumor, while hardly releasing energy when passing through normal tissues. Therefore, the pencil beam spot scanning technology can significantly reduce radiation damage to surrounding normal tissues and reduce treatment side effects.

[0056] To solve the technical problems of complex current regulation mode and magnetic hysteresis caused by magnet eddy current in the existing technology, the present invention provides a precise positioning method for proton movement, innovatively proposing to combine spatial geometric analysis with proton physical characteristics and electromagnetics, and applying it to the deflection movement of protons in the scanning magnetic field. Please refer to Figure 1 As shown, the precise positioning method for proton movement includes the following steps:

[0057] S100: Construct a spatial geometric model based on the deflection movement trajectory of the proton moving to a preset target position under the action of the scanning magnetic field, and perform spatial geometric analysis according to the spatial geometric model to obtain the deflection radius of the proton in the scanning magnetic field;

[0058] S200: According to the deflection radius and the magnetic rigidity of the proton, obtain the target magnetic field intensity of the scanning magnetic field required for the proton to move to the preset target position;

[0059] S300: Obtain the actual magnetic field intensity of the scanning magnetic field;

[0060] S400: According to the target magnetic field intensity and the actual magnetic field intensity, obtain the target current of the scanning magnet corresponding to the scanning magnetic field;

[0061] S500: Control the deflection of the proton movement trajectory in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement.

[0062] The steps of the above-mentioned precise positioning method for proton movement will be discussed in detail below.

[0063] First, perform step S100 to construct a spatial geometric model based on the deflection motion trajectory of protons moving to a preset target position under the action of a scanning magnetic field, and perform spatial geometric analysis based on the spatial geometric model to obtain the deflection radius of the protons in the scanning magnetic field.

[0064] In an exemplary embodiment of the present application, the step of constructing a spatial geometric model based on the deflection motion trajectory of protons moving to a preset target position under the action of a scanning magnetic field, and performing spatial geometric analysis based on the spatial geometric model to obtain the deflection radius of the protons in the scanning magnetic field further includes the following steps:

[0065] S101: Take the first direction as the X-axis, the second direction as the Y-axis, the central axis of the proton beam emitted from the accelerator as the Z-axis, and the incident position of the protons entering the first-direction scanning magnetic field as the origin to establish a three-dimensional space coordinate system;

[0066] S102: Obtain the distance of the first-direction scanning magnetic field on the Z-axis;

[0067] S103: Obtain the coordinate value of the preset target position on the Z-axis;

[0068] S104: Obtain the coordinate value of the preset target position on the X-axis;

[0069] S105: Perform geometric calculations based on the distance of the first-direction scanning magnetic field on the Z-axis, the coordinate value of the preset target position on the Z-axis, and the coordinate value of the preset target position on the X-axis to obtain the deflection radius of the protons in the first-direction scanning magnetic field.

[0070] It should be noted that, as shown in Figure 2 The scanning magnetic field includes a first-direction scanning magnetic field and a second-direction scanning magnetic field, wherein the first direction and the second direction are perpendicular to each other. In an exemplary embodiment of the present application, the first-direction scanning magnetic field is the X-direction scanning magnetic field, and the second-direction scanning magnetic field is the Y-direction scanning magnetic field. In addition, the preset target position can be any point on the isocenter plane of the tissue layer.

[0071] Specifically, as shown in Figure 3 shown, Figure 3 is a geometric analysis diagram of the deflection motion trajectory of protons in the X-direction scanning magnetic field, Figure 3In the two-dimensional Z-X coordinate system, a proton M (with energy T) enters the scanning magnetic field from point O perpendicular to the direction of the XY scanning magnetic field intensity (Bx, By) and undergoes a deflection motion, precisely moving to point Pn(x, y) on the isocenter plane Zn of the tissue layer. Here, Pn is an arbitrary point on the isocenter plane Zn of the tissue layer. It should be noted that Figure 3 The red curve shown in is the deflection motion trajectory of the proton in the X-direction scanning magnetic field. The reverse extensions of line 1, line 2, and line 3 intersect at point e (not shown). Using the Pythagorean theorem and the law of similar triangles for geometric analysis, since △abc is similar to △aPnZn and △aOe is similar to △bOc, we can obtain:

[0072]

[0073] bc 2 = ab 2 - ac 2 (2)

[0074]

[0075] Oa = ab, ac = Oc - Oa, aZn = OZn - Oa, PnZn = x, Oe = rx (4)

[0076] Among them, Oc is the distance of the first-direction scanning magnetic field on the Z-axis, OZn is the coordinate value of the preset target position on the Z-axis, x is the coordinate value of the preset target position on the X-axis, Oc, OZn, and x are known quantities with the unit of meter; rx is the deflection radius of the proton in the X-direction scanning magnetic field, rx is an unknown quantity with the unit of meter; Oa is an unknown quantity with the unit of meter.

[0077] Let Oc = A, OZm = B, Oa = K, simplify the equations (1)(2)(3)(4), and we can obtain:

[0078] 2A·K 3 -(4AB + A 2 + x 2 )·K 2 +(2AB 2 [[ID=�9]]+ 2A 2 B + 2Ax 2 )·K - A 2 x 2 = 0 (5)

[0079] Let L = 2A, M = -(4AB + A 2 + x 2 ),N = 2AB 2 + 2A 2 B + 2Ax 2 ,Q = -A 2 x2 , substituting into Equation (5) gives:

[0080] L·K 3 +M·K 2 +N·K + Q = 0 (6)

[0081] According to Cardano's formula method, L≠0. Divide Equation (6) by L, and let

[0082] Substituting (7) into Equation (6) gives:

[0083] H 3 +p·H + q = 0, where

[0084] The real roots of Equation (8) can be obtained:

[0085]

[0086]

[0087] It should be noted that the mathematical calculation method of the deflection radius rx of the proton in the X - direction scanning magnetic field is also applicable to the calculation of the deflection radius ry of the proton in the Y - direction scanning magnetic field.

[0088] Next, perform step S200 to obtain the target magnetic field intensity of the scanning magnetic field required for the proton to move to the preset target position according to the deflection radius and the proton energy. It should be noted that the target magnetic field intensity includes the target magnetic field intensity of the X - direction scanning magnetic field and the target magnetic field intensity of the Y - direction scanning magnetic field.

[0089] In an exemplary embodiment of the present application, in step S200, the obtaining of the target magnetic field intensity of the scanning magnetic field required for the proton to move to the preset target position according to the deflection radius and the proton energy further includes the following steps:

[0090] S201: Obtain the magnetic rigidity constant of the proton according to the proton energy;

[0091] S202: Calculate the target magnetic field intensity of the scanning magnetic field required for the proton to move to the preset target position according to the magnetic rigidity constant and the deflection radius.

[0092] Specifically, according to the physical characteristics of the proton beam, that is, when protons at each energy level T move in a circular motion in a perpendicular magnetic field, there is a unique magnetic rigidity Bρ constant, and its calculation formula is:

[0093]

[0094] The formula (12) can be transformed as follows:

[0095]

[0096] Among them, T is the proton energy, with the unit of MeV, E0 is the proton rest energy, E0 = 938.27 MeV, c is the speed of light, c = 299792458 m / s, and r is the deflection radius of the proton in the scanning magnetic field, with the unit of meter.

[0097] The proton M (with energy T) enters the scanning magnetic field from point O in a direction perpendicular to the XY scanning magnetic field intensity (Bx, By) and makes a deflection motion. The target magnetic field intensity (SmBxsetpoint, SmBysetpoint) of the XY uniform scanning magnetic field required to accurately move to the point Pn(x, y) on the tissue layer isocenter plane Zn is calculated according to formula (13) and can be obtained as follows:

[0098]

[0099] Among them, rx is the deflection radius of the proton in the X-direction scanning magnetic field, with the unit of meter.

[0100]

[0101] Among them, ry is the deflection radius of the proton in the Y-direction scanning magnetic field, with the unit of meter.

[0102] Immediately afterwards, step S300 is executed to obtain the actual magnetic field intensity of the scanning magnetic field. It should be noted that the actual magnetic field intensity includes the actual magnetic field intensity of the X-direction scanning magnetic field and the actual magnetic field intensity of the Y-direction scanning magnet.

[0103] It should be noted that the beam with a fixed energy of the proton therapy system comes out of the cyclotron, passes through the transport line and enters the treatment head to irradiate the patient. Usually, by reducing the beam energy T, it irradiates from the distal end to the proximal end of the tumor, and the magnetic field and current of the corresponding scanning magnet are dynamically reduced. During irradiation, the magnetic field is required to be accurate and stable.

[0104] Please refer to Figure 4(As shown in CN117379702A), where saturation represents the magnetic field saturation point and remanent field represents the residual magnetic field. During the normal irradiation process of the scanning magnet, it descends along curve II to B. If additional energy is required, simply increasing the current will cause it to move from B to C along the curve. Then, when the current is decreased again, a new excitation curve is formed and no longer follows curve II. This results in multiple magnetic fields corresponding to a single current, introducing uncertainties in irradiation. If energy increase or repeated irradiation is involved, the current of the scanning magnet needs to be increased. The common practice is to first increase the current of the scanning magnet to its maximum, reaching the magnetic field saturation point of the scanning magnet, and then descend along the hysteresis curve to the required current for irradiation. This process is complex and takes up some time, leading to a relatively long irradiation time. This mode is called current regulation. Please refer to Figure 5 (As shown in CN117379702A), when the scanning magnet increases or decreases its current, due to the eddy current effect, the magnetic field always lags behind the current to reach equilibrium. This delay time is called the settling time, where Figure 5 Figure (a) in Figure 5 shows the settling time when the scanning magnet increases its current,

[0105] To achieve the purpose of rapid magnetic field regulation, Hall probes are introduced and installed at the outlet and inlet of the XY scanning magnetic field to detect the magnitude of the magnetic field (Bx, By) in real time. By reading the real-time magnetic field values of the Hall probes, the current value of the scanning magnet is dynamically adjusted. This mode is called field regulation.

[0106] In an exemplary embodiment of the present application, the actual magnetic field intensity of the scanning magnetic field is detected in real time by Hall probes respectively installed at the outlet and inlet of the scanning magnetic field, where the Hall probes at the outlet and inlet of the scanning magnetic field have a redundant verification relationship with each other. It should be noted that the redundant verification relationship can reduce the risks caused by measurement errors or system failures. When one of the Hall probes fails, the other Hall probe can continue to work normally, thus ensuring the continuity and accuracy of the measurement.

[0107] Next, step S400 is executed to obtain the target current of the scanning magnet corresponding to the scanning magnetic field based on the target magnetic field intensity and the actual magnetic field intensity.

[0108] In an exemplary embodiment of the present application, the step of obtaining the target current of the scanning magnet corresponding to the scanning magnetic field based on the target magnetic field intensity and the actual magnetic field intensity further includes the following steps:

[0109] S401: Obtain the scanning magnetic field intensity deviation between the target magnetic field intensity of the scanning magnetic field and the actual magnetic field intensity of the scanning magnetic field;

[0110] S402: According to the scanning magnetic field intensity deviation, obtain the target current of the scanning magnet corresponding to the scanning magnetic field through PID operation.

[0111] Specifically, in the XY scanning magnetic field, 2 PID operations are applied to obtain the target currents Ix,output(t) and Iy,output(t) of the scanning magnets corresponding to the X-direction scanning magnetic field and the Y-direction scanning magnetic field in real time. Let the scanning magnetic field intensity deviations of the X-direction scanning magnetic field and the Y-direction scanning magnetic field be eBx and eBy respectively, then:

[0112] eBx(t) = SmBxsetpoint(t) - SmBxfb(t)

[0113] eBy(t) = SmBysetpoint(t) - SmByfb(t)

[0114] Among them, SmBxsetpoint is the target magnetic field intensity of the X-direction scanning magnetic field, SmBysetpoint is the target magnetic field intensity of the Y-direction scanning magnetic field, SmBxfb is the actual magnetic field intensity real-time feedback by the Hall probe of the X-direction scanning magnetic field, and SmByfb is the actual magnetic field intensity real-time feedback by the Hall probe of the Y-direction scanning magnetic field.

[0115] After time t, it can be obtained:

[0116]

[0117] Among them, △t is the sampling period of the real-time feedback data of the Hall probe, SmpsyPidKp is the proportional adjustment in the PID control algorithm, SmpsxPidKi is the integral adjustment in the PID control algorithm, and SmpsxPidKd is the differential adjustment in the PID control algorithm.

[0118] Finally, execute step S500, and control the deflection of the proton's movement trajectory in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement.

[0119] Specifically, send the target current values of the X-direction scanning magnet current Ix,output(t) and the Y-direction scanning magnet current Iy,output(t) obtained by the real-time operation of the formulas (17)(18) algorithm to the XY scanning magnet power supply control unit to regulate the magnetic field intensity of the XY scanning magnetic field, and the regulation effect is as Figure 6 and Figure 7As shown, where "no field regulation" represents the situation before magnetic field regulation, "with field regulation" represents the situation after magnetic field regulation, "error on B due to the hysteresis" represents the error of the magnetic field strength B caused by the hysteresis effect, and ΔB = B A - B C represents the error value of the magnetic field strength, and ΔI = I A′ - I A or ΔI = I A′ - I C represents the error value of the current.

[0120] Based on the same inventive concept, another embodiment of the present invention further provides a pencil beam spot scanning treatment head, and the pencil beam spot scanning treatment head controls the proton movement by using the precise positioning method of proton movement described in any of the above embodiments. Since the pencil beam spot scanning treatment head provided in this embodiment and the precise positioning method of proton movement provided in any of the above embodiments belong to the same inventive concept, therefore, it has at least the same beneficial effects as it, and will not be described in detail here.

[0121] Based on the same inventive concept, please refer to Figure 8 as shown, another embodiment of the present invention further provides a precise positioning device 11 for proton movement, including:

[0122] A deflection radius acquisition module 111, which is used to construct a spatial geometric model according to the deflection movement trajectory of the proton moving to a preset target position under the action of the scanning magnetic field, and perform spatial geometric analysis according to the spatial geometric model to obtain the deflection radius of the proton in the scanning magnetic field;

[0123] A target magnetic field strength acquisition module 112, which is used to obtain the target magnetic field strength of the scanning magnetic field required for the proton to move to the preset target position according to the deflection radius and the proton energy;

[0124] A target current acquisition module 113, which is used to obtain the actual magnetic field strength of the scanning magnetic field, and obtain the target current of the scanning magnet corresponding to the scanning magnetic field according to the target magnetic field strength and the actual magnetic field strength;

[0125] A movement control module 114 controls the deflection movement trajectory of the proton in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement.

[0126] Based on the same inventive concept, please refer to Figure 9As shown, another embodiment of the present invention further provides an electronic device 1, which may include a memory 12, a processor 13 and a bus, and may also include a computer program stored in the memory 12 and executable on the processor 13, such as a precise positioning program for proton motion.

[0127] Among them, the memory 12 includes at least one type of readable storage medium, which includes flash memory, mobile hard disk, multimedia card, card-type memory (such as: SD or DX memory, etc.), magnetic memory, magnetic disk, optical disk, etc. The memory 12 may be an internal storage unit of the electronic device 1 in some embodiments, such as the mobile hard disk of the electronic device 1. The memory 12 may also be an external storage device of the electronic device 1 in other embodiments, such as a plug-in mobile hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the electronic device 1. Further, the memory 12 may include both an internal storage unit and an external storage device of the electronic device 1. The memory 12 can be used not only to store application software installed on the electronic device 1 and various types of data, such as the code for precise positioning of proton motion, etc., but also to temporarily store data that has been output or will be output.

[0128] The processor 13 may be composed of integrated circuits in some embodiments. For example, it may be composed of a single packaged integrated circuit, or may be composed of multiple integrated circuits with the same or different functions, including a combination of one or more Central Processing Units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 13 is the control core (Control Unit) of the electronic device 1, connecting various components of the entire electronic device 1 through various interfaces and lines, and by running or executing programs or modules (such as the precise positioning program for proton motion, etc.) stored in the memory 12, and calling data stored in the memory 12, to execute various functions of the electronic device 1 and process data.

[0129] The processor 13 executes the operating system of the electronic device 1 and various installed application programs. The processor 13 executes the application program to implement the steps in the above-mentioned precise positioning method for proton motion.

[0130] Exemplarily, the computer program may be divided into one or more modules, which are stored in the memory 12 and executed by the processor 13 to complete the present application. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, and these instruction segments are used to describe the execution process of the computer program in the electronic device 1. For example, the computer program may be divided into a deflection radius acquisition module 111, a target magnetic field strength acquisition module 112, a target current acquisition module 113, and a motion control module 114.

[0131] The integrated units implemented in the form of software function modules as described above may be stored in a computer-readable storage medium, which may be non-volatile or volatile. The above-mentioned software function modules are stored in a storage medium and include several instructions for causing a computer device (which may be a personal computer, a computer device, or a network device, etc.) or a processor to execute some functions of the precise positioning method for proton motion described in various embodiments of the present application.

[0132] In summary, a precise positioning method for proton movement provided by the present invention is applied to a pencil beam spot scanning treatment head. The method includes: constructing a spatial geometric model according to the deflection movement trajectory of a proton moving to a preset target position under the action of a scanning magnetic field, and performing spatial geometric analysis according to the spatial geometric model to obtain the deflection radius of the proton in the scanning magnetic field; obtaining the target magnetic field intensity of the scanning magnetic field required for the proton to move to the preset target position according to the deflection radius and the magnetic rigidity of the proton; obtaining the actual magnetic field intensity of the scanning magnetic field; obtaining the target current of the scanning magnet corresponding to the scanning magnetic field according to the target magnetic field intensity and the actual magnetic field intensity; and controlling the deflection of the movement trajectory of the proton in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement. The precise positioning method for proton movement of the present invention innovatively proposes to combine spatial geometric analysis with proton physical properties and electromagnetics and apply it to the deflection movement of protons in the XY scanning magnetic field. By establishing known quantities, a spatial geometric model is constructed based on the proton deflection movement path to solve the proton deflection radius r. According to the proton energy T, the magnetic rigidity Bρ of the scanning magnetic field is solved, and according to the magnetic rigidity Bρ, the magnetic field intensity B is solved. By using a Hall probe to real-time collect the scanning magnetic field intensity B, for the magnetic field deviation △B within the sampling period, the PID algorithm is applied to automatically calculate and real-time refresh the target setting value I of the scanning magnet current, thereby obtaining the relationship between the proton energy T and any point Pn(x, y) on the isocenter plane Zn of the tissue layer and the XY scanning magnet current (Ix, Iy). Finally, by adjusting the magnitudes of the XY scanning magnet operating currents Ix and Iy, the movement trajectory of the proton is deflected, so that the proton precisely moves to the spot position point Pn(x, y) on the isocenter plane Zn of the tumor tissue layer.

[0133] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A precise positioning method for proton movement, characterized in that Applied to a pencil beam spot scanning therapy head, the method includes: Construct a spatial geometric model based on the deflection trajectory of protons moving to a preset target position under the action of a scanning magnetic field, and perform spatial geometric analysis according to the spatial geometric model to obtain the deflection radius of the protons in the scanning magnetic field; Based on the deflection radius and proton energy, obtain the target magnetic field strength of the scanning magnetic field required for the protons to move to the preset target position; Obtain the actual magnetic field strength of the scanning magnetic field; Based on the target magnetic field strength and the actual magnetic field strength, obtain the target current of the scanning magnet corresponding to the scanning magnetic field; Control the deflection trajectory of the protons in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement.

2. The precise positioning method of proton movement according to claim 1, wherein The scanning magnetic field includes a first-direction scanning magnetic field and a second-direction scanning magnetic field, where the first direction and the second direction are perpendicular to each other.

3. The precise positioning method of proton movement according to claim 2, characterized in that The geometric analysis according to the spatial geometric model to obtain the deflection radius of the protons in the scanning magnetic field includes: Taking the first direction as the X-axis, the second direction as the Y-axis, the central axis of the proton beam emitted from the accelerator as the Z-axis, and the incident position of the protons entering the first-direction scanning magnetic field as the origin, establish a three-dimensional space coordinate system; Obtain the distance of the first-direction scanning magnetic field on the Z-axis; Obtain the coordinate value of the preset target position on the Z-axis; Obtain the coordinate value of the preset target position on the X-axis; Perform geometric calculations based on the distance of the first-direction scanning magnetic field on the Z-axis, the coordinate value of the preset target position on the Z-axis, and the coordinate value of the preset target position on the X-axis to obtain the deflection radius of the protons in the first-direction scanning magnetic field.

4. The precise positioning method of proton movement according to claim 1, characterized in that The obtaining the target magnetic field strength of the scanning magnetic field required for the protons to move to the preset target position based on the deflection radius and proton energy includes: Obtain the magnetic rigidity constant of the protons according to the proton energy; Based on the magnetic rigidity constant and the deflection radius, calculate the target magnetic field strength of the scanning magnetic field required for the protons to move to the preset target position.

5. The precise positioning method of proton movement according to claim 4, characterized in that The calculation formula for the target magnetic field strength of the scanning magnetic field is: Where B is the target magnetic field strength, T is the proton energy, E0 is the proton rest energy, c is the speed of light, and r is the deflection radius of the protons in the scanning magnetic field.

6. The precise positioning method of proton movement according to claim 1, characterized in that, The obtaining the actual magnetic field strength of the scanning magnetic field includes: Real-time detect the actual magnetic field strength of the scanning magnetic field through Hall probes respectively installed at the outlet and inlet of the scanning magnetic field, where the Hall probes at the outlet and inlet of the scanning magnetic field are in a redundant verification relationship.

7. The precise positioning method of proton movement according to claim 1, characterized in that, The obtaining the target current of the scanning magnet corresponding to the scanning magnetic field based on the target magnetic field strength and the actual magnetic field strength includes: Obtain the scanning magnetic field strength deviation between the target magnetic field strength of the scanning magnetic field and the actual magnetic field strength of the scanning magnetic field; Based on the scanning magnetic field strength deviation, obtain the target current of the scanning magnet corresponding to the scanning magnetic field through PID operation.

8. A pen-shaped beam spot scanning treatment head, characterized in that, The pen-shaped beam spot scanning therapy head uses the precise positioning method of proton movement described in any one of claims 1-7 to control proton movement.

9. A precise positioning device for proton movement, characterized in that, It includes: A deflection radius acquisition module, configured to construct a spatial geometric model according to the deflection movement trajectory of the proton moving to a preset target position under the action of a scanning magnetic field, and perform spatial geometric analysis according to the spatial geometric model to obtain the deflection radius of the proton in the scanning magnetic field; A target magnetic field intensity acquisition module, configured to obtain the target magnetic field intensity of the scanning magnetic field required for the proton to move to a preset target position according to the deflection radius and proton energy; A target current acquisition module, configured to obtain the actual magnetic field intensity of the scanning magnetic field, and obtain the target current of the scanning magnet corresponding to the scanning magnetic field according to the target magnetic field intensity and the actual magnetic field intensity; A movement control module, which controls the deflection movement trajectory of the proton in the scanning magnetic field according to the target current to achieve precise positioning of the proton movement.

10. An electronic device, characterized in that, The electronic device includes: One or more processors; A storage device, configured to store one or more programs, and when the one or more programs are executed by the one or more processors, enable the electronic device to implement the precise positioning method of proton movement described in any one of claims 1 to 7.

11. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and when the computer program is executed by a processor of a computer, the computer is enabled to execute the precise positioning method of proton movement described in any one of claims 1 to 7.

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