Control method and device of multi-leaf collimator and multi-leaf collimator structure of linear accelerator

Abstract

The application provides a control method and device of a multi-leaf collimator and a multi-leaf collimator structure of a linear accelerator. The method is applied to a first layer leaf group of a layered multi-leaf collimator structure including two layer leaf groups. The first layer leaf group includes n leaves, the second layer leaf group includes n+1 leaves, the first layer leaf group is located above the second layer leaf group, the leaves in the two layer leaf groups are staggered, and the first layer leaf group and the second layer leaf group include leaves with different thicknesses. Leaf control signals in multiple control periods are obtained. The leaf control signals include control signals corresponding to the leaves in the first layer leaf group and the second layer leaf group. In each control period, at least one leaf in the two layer leaf groups is controlled to rotate in response to the leaf control signals. The rotation of the driving motor drives the leaves controlled by the driving motor to move in a target moving direction by a target moving distance, so that the two layer leaf groups form an irregular shape radiation field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical equipment, in particular to a control method and device of a multi-leaf collimator and a multi-leaf collimator structure of a linear accelerator. BACKGROUND

[0002] The multi-leaf collimator (MLC) is a core component of a medical linear accelerator for realizing radiation beam shaping. A radiation field matching the shape of a tumor target region is formed by the opening and closing combination of pairs of leaves, and the leaf position accuracy directly determines the accuracy of the radiotherapy dose and the protection effect of the normal tissue around the target region.

[0003] The multi-leaf collimator in the related art generally uses single-layer leaves to realize the formation of a radiation field, but has the problems of low isocenter accuracy and single detection mode. SUMMARY

[0004] Therefore, the present application provides a control method and device of a multi-leaf collimator and a multi-leaf collimator structure of a linear accelerator.

[0005] Specifically, the present application is realized by the following technical solutions:

[0006] In a first aspect, the present application provides a control method of a multi-leaf collimator, applied to a layered multi-leaf collimator structure, the layered multi-leaf collimator structure comprising two leaf groups, the first leaf group comprising n leaves, the second leaf group comprising n+1 leaves, the first leaf group being located above the second leaf group, and the leaves in the two leaf groups being staggered, the first leaf group comprising a plurality of leaves with different thicknesses, the second leaf group comprising a plurality of leaves with different thicknesses, n being a positive integer; the method comprising:

[0007] obtaining leaf control signals in a plurality of control periods, the leaf control signals comprising control signals corresponding to a plurality of leaves in the first leaf group and the second leaf group respectively;

[0008] in each control period, in response to the leaf control signals, controlling a driving motor corresponding to at least one leaf in the two leaf groups to rotate;

[0009] using the rotation of the driving motor to drive the leaf controlled by the driving motor to move a target moving distance in a target moving direction, so that the two leaf groups form an irregularly shaped radiation field.

[0010] Optionally, a plurality of leaves in the first leaf group are arranged on a first circuit board, and a plurality of leaves in the second leaf group are arranged on a second circuit board.

[0011] The first layer of the blade group includes x first blades and y second blades, the average thickness of the first blades is greater than the average thickness of the second blades; the second layer of the blade group includes x+2 third blades and y-1 fourth blades, the average thickness of the third blades is greater than the average thickness of the fourth blades;

[0012] The second blades are concentrated in the middle area of the first layer of the circuit board, the first blades are divided into two parts and arranged on both sides of the second blades, the fourth blades are concentrated in the middle area of the second layer of the circuit board, the third blades are divided into two parts and arranged on both sides of the fourth blades, x and y are positive integers, and the sum of x and y is equal to n.

[0013] Optionally, each of the blades is provided with at least one magnetic bead, and a target area connected with the blades on the first layer of the circuit board and the second layer of the circuit board is provided with a plurality of groups of magnetic sensors; the method further comprises:

[0014] According to the driving encoder information corresponding to the driving motor, the target moving direction and the target moving distance of the at least one blade are determined; and according to the acquisition signals of the plurality of groups of magnetic sensor groups, the current moving direction and the current moving distance of the at least one blade are determined;

[0015] When the target moving direction is consistent with the current moving direction, and the deviation value between the target moving distance and the current moving distance is less than or equal to the set deviation threshold value, first feedback information indicating that the moving accuracy of the two-layer blade group is qualified is generated.

[0016] Optionally, the method further comprises: when the target moving direction is inconsistent with the current moving direction, and / or the deviation value between the target moving distance and the current moving distance is greater than the set deviation threshold value, second feedback information indicating that the two-layer blade group moves fails is generated, and an alarm information is triggered.

[0017] Optionally, the side of the target leaf connected with the target circuit board is provided with a plurality of grooves, and each groove is provided with a plurality of magnetic beads according to a first target interval; there is a leaf protrusion region between adjacent two grooves; the target area of the target circuit board connected with the target leaf is provided with four groups of magnetic sensors, and the first group of magnetic sensors, the second group of magnetic sensors, the third group of magnetic sensors and the fourth group of magnetic sensors are arranged in sequence in the movement direction of the target leaf; wherein when the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board; when the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board; wherein the diameter of the magnetic bead is the same as the width of the magnetic sensor, the first target interval is a multiple of the diameter of the magnetic bead, and the width of the leaf protrusion region is 2 times the first target interval minus the difference of the diameter of the magnetic bead;

[0018] The current moving direction and the current moving distance of the at least one leaf are determined according to the acquisition signals of the plurality of groups of magnetic sensors, including:

[0019] During the movement of the leaf, the acquisition signals of the four groups of magnetic sensors corresponding to the leaf are continuously detected;

[0020] The acquisition signals of the first group of magnetic sensors and the fourth group of magnetic sensors are ANDed to obtain a first level signal, and the acquisition signals of the second group of magnetic sensors and the third group of magnetic sensors are ANDed to obtain a second level signal;

[0021] The current moving direction of the leaf is determined according to the combination transformation state of the first level signal and the second level signal;

[0022] The current moving distance of the leaf is determined according to the signal change state of the first level signal.

[0023] Optionally, the side of the target leaf connected with the target circuit board is provided with a groove, and the groove is provided with a magnetic bead; the target area of the target circuit board connected with the target leaf is continuously provided with a plurality of groups of magnetic sensors; wherein when the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board; when the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board;

[0024] The current moving direction and the current moving distance of the at least one leaf are determined according to the acquisition signals of the plurality of groups of magnetic sensors, including:

[0025] During the movement of the leaf, the acquisition signals of the plurality of groups of magnetic sensors corresponding to the leaf are continuously detected;

[0026] According to signal change states of the collected signals of the multiple groups of magnetic sensors, the current moving direction and the current moving distance of the leaf are determined.

[0027] Optionally, one side of the target leaf connected with the target circuit board is provided with a groove, and a plurality of magnetic beads are arranged in the groove according to a second target interval; the target area of the target circuit board connected with the target leaf is provided with two groups of magnetic sensors, and the first group of magnetic sensors and the second group of magnetic sensors are arranged in sequence in the moving direction of the target leaf; wherein when the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board, and when the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board; the diameter of the magnetic bead is the same as the width of the magnetic sensor, and the second target interval is a multiple of the diameter of the magnetic bead.

[0028] According to the collected signals of the multiple groups of magnetic sensors, the current moving direction and the current moving distance of the at least one leaf are determined, which includes:

[0029] During the movement of the leaf, the collected signals of the two groups of magnetic sensors corresponding to the leaf are continuously detected;

[0030] According to the signal change states of the collected signals of the two groups of magnetic sensors, the current moving direction of the leaf is determined, and according to the signal change state of any one of the two groups of magnetic sensors, the current moving distance of the leaf is determined.

[0031] In a second aspect, the embodiments of the present application also provide a multi-leaf collimator structure of a linear accelerator, two leaf groups, n leaves in the first layer leaf group, n+1 leaves in the second layer leaf group, the first layer leaf group is located above the second layer leaf group, and the leaves in the two leaf groups are staggered, the first layer leaf group includes a plurality of leaves with different thicknesses, the second layer leaf group includes a plurality of leaves with different thicknesses, and n is a positive integer; wherein the leaves in the two leaf groups are controlled by the control method of the multi-leaf collimator of any one of the first aspect.

[0032] In a third aspect, the embodiments of the present application also provide a control device of a multi-leaf collimator, which is applied to a layered multi-leaf collimator structure, the layered multi-leaf collimator structure includes two leaf groups, n leaves in the first layer leaf group, n+1 leaves in the second layer leaf group, the first layer leaf group is located above the second layer leaf group, and the leaves in the two leaf groups are staggered, the first layer leaf group includes a plurality of leaves with different thicknesses, the second layer leaf group includes a plurality of leaves with different thicknesses, and n is a positive integer; the device includes:

[0033] The acquisition module is configured to acquire blade control signals in multiple control periods, wherein the blade control signals include control signals corresponding to multiple blades in the first layer blade group and the second layer blade group respectively.

[0034] The control module is configured to control a driving motor corresponding to at least one blade in the two-layer blade group to rotate in each control period in response to the blade control signals, so that the driving motor controls the blade to move a target moving distance in a target moving direction, and the two-layer blade group forms an irregular shape radiation field.

[0035] The application provides a computer readable storage medium, which stores a computer program. The computer program is executed by a processor to implement the control method of the multi-leaf collimator.

[0036] The application provides a computer device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor implements the control method of the multi-leaf collimator when executing the program.

[0037] The multi-layer multi-leaf collimator structure provided in the application controls the driving motor corresponding to the blade to rotate in each control period according to the blade control signals, so as to control each blade in the two-layer blade group by the driving motor, thereby realizing accurate control of the multi-leaf collimator structure. The design of the two-layer blade group also guarantees the accuracy of the multi-leaf collimator structure and meets the requirement of the business side for the accuracy of the equal center position. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings, which are included to provide a further understanding of the present application, constitute a part of the specification and illustrate the exemplary embodiments of the present application and the description thereof, and do not limit the present application. In the drawings:

[0039] Figure 1 FIG. 1 is a structural schematic diagram of a hierarchical multi-leaf collimator structure according to an exemplary embodiment of the present application;

[0040] Figure 2 FIG. 5 is a flowchart of a control method of a multi-leaf collimator according to an exemplary embodiment of the present application;

[0041] Figure 3 FIG. 6 is a schematic diagram of a first layer circuit board in a hierarchical multi-leaf collimator structure according to an exemplary embodiment of the present application;

[0042] Figure 4 FIG. 7 is a schematic diagram of the relative position of a magnetic bead and a blade in a hierarchical multi-leaf collimator structure according to an exemplary embodiment of the present application;

[0043] Figure 5 is one of the schematic diagrams of the change of the collection signal of the magnetic sensor caused by the movement of the magnetic beads driven by the leaflets in a control method of a multileaf collimator according to an example embodiment of the present application;

[0044] Figure 6 is the second schematic diagram of the relative position between the magnetic beads and the leaflets in a layered multileaf collimator structure according to an example embodiment of the present application;

[0045] Figure 7 is the second schematic diagram of the change of the collection signal of the magnetic sensor caused by the movement of the magnetic beads driven by the leaflets in a control method of a multileaf collimator according to an example embodiment of the present application;

[0046] Figure 8 is the third schematic diagram of the relative position between the magnetic beads and the leaflets in a layered multileaf collimator structure according to an example embodiment of the present application;

[0047] Figure 9 is the third schematic diagram of the change of the collection signal of the magnetic sensor caused by the movement of the magnetic beads driven by the leaflets in a control method of a multileaf collimator according to an example embodiment of the present application;

[0048] Figure 10 is a schematic diagram of a control device of a multileaf collimator according to an example embodiment of the present application;

[0049] Figure 11 is a structural schematic diagram of a computer device provided by the present application. DETAILED DESCRIPTION

[0050] The example embodiments will be described in detail herein with reference to the attached drawings. When the description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The following description of example embodiments is not representative of all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the appended claims.

[0051] The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the present application and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0052] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various information, the information should not be limited to these terms. These terms are only used to distinguish one type of information from another type of information. For example, without departing from the scope of the present application, first information can also be referred to as second information, and similarly, second information can also be referred to as first information. Depending on the context, the word "if' as used herein can be interpreted as "when" or "upon" or "in response to determining".

[0053] To facilitate the understanding of the present embodiment, first, a control method of a multi-leaf collimator disclosed by the present application is introduced in detail. The control method of the multi-leaf collimator provided by the present embodiment is applied to a layered multi-leaf collimator structure.

[0054] As shown in the figure, Figure 1 The layered multi-leaf collimator structure of the present application includes two leaf banks. The first leaf bank 11 includes n leaves, and the second leaf bank 12 includes n+1 leaves. The first leaf bank 11 is located above the second leaf bank 12, and the leaves in the two leaf banks are staggered. The first leaf bank includes multiple leaves with different thicknesses, the second leaf bank includes multiple leaves with different thicknesses, and n is a positive integer.

[0055] For example, the material and thickness of the leaves of the present application can be selected according to actual needs. For example, the leaves can be made of tungsten alloy. For example, the first leaf bank 11 can include first thin leaves 111 and first thick leaves 112, and the second leaf bank 12 can include second thin leaves 121 and second thick leaves 122. For example, the thickness of the thin leaves can be 2.5mm, and the thickness of the thick leaves can be 5mm.

[0056] The number of the first leaf bank and the second leaf bank can be set according to actual needs. For example, the value of n can be 37, that is, the first leaf bank includes 37 leaves, and the second leaf bank includes 38 leaves. The first leaf bank is the upper leaf bank, and the second leaf bank is the lower leaf bank. The upper and lower two leaf banks are staggered, forming a gapless radiation field shielding, which can reduce the leakage rate and the half-shadow width, reduce the normal tissue dose, and improve the accuracy of the multi-leaf collimator.

[0057] As shown in the figure, Figure 2 The present embodiment provides a flow chart of the control method of the multi-leaf collimator. The method includes steps S201-S203, wherein:

[0058] S201, acquiring a leaf control signal under a plurality of control periods, the leaf control signal including a control signal corresponding to each of a plurality of leaves in the first leaf bank and the second leaf bank.

[0059] In implementation, the blade control signals in multiple control periods can be generated according to actual conditions of the user, so that the two-layer blade groups form an irregular radiation field that fits the user in each control period.

[0060] The blade control signals in multiple control periods include control signals corresponding to multiple blades in the first-layer blade group and the second-layer blade group; the number and positions of the blades controlled in each control period are determined according to actual needs.

[0061] S202, in each control period, at least one drive motor corresponding to a blade in the two-layer blade group is controlled to rotate in response to the blade control signal.

[0062] In each control period, at least one drive motor corresponding to a blade in the two-layer blade group is controlled to rotate in a specific direction in response to the blade control signal in the control period, so as to drive the blade to move to a specific position. Each blade can correspond to at least one drive motor, and different drive motors are used to control different blades to move.

[0063] S203, the drive motor is used to drive the blade controlled by the drive motor to move a target moving distance in a target moving direction, so that the two-layer blade group forms an irregular radiation field.

[0064] In implementation, the drive motor can be connected to the blade, and the blade connected to the drive motor is driven to move a target moving distance in a target moving direction through rotation of the drive motor, where the target moving direction and the target moving distance are a reference moving direction and a reference moving distance of the blade determined according to the blade control signal.

[0065] The application can use a Field Programmable Gate Array (FPGA) chip to realize real-time and accurate control of the multi-leaf collimator structure. The drive motor can be a direct current brush motor, and a Proportional-Integral-Derivative (PID) control algorithm can be used to realize smooth movement of the blade.

[0066] The multi-layer multi-leaf collimator structure proposed in the application controls the drive motor corresponding to the blade to rotate in each control period according to the blade control signal, so as to control each blade in the two-layer blade group by using the drive motor, realizes accurate control of the multi-leaf collimator structure, and the design of the two-layer blade group also guarantees the accuracy of the multi-leaf collimator structure, meeting the requirement of the business side for the accuracy of the equal center position.

[0067] In an alternative embodiment, the plurality of blades in the first layer blade group are disposed on a first layer circuit board, and the plurality of blades in the second layer blade group are disposed on a second layer circuit board.

[0068] The first layer blade group includes x first blades and y second blades, the average thickness of the first blades being greater than the average thickness of the second blades; the second layer blade group includes x+2 third blades and y-1 fourth blades, the average thickness of the third blades being greater than the average thickness of the fourth blades;

[0069] The second blades are centrally disposed on the first layer circuit board, and the first blades are divided into two portions and disposed on both sides of the second blades; the fourth blades are centrally disposed on the second layer circuit board, and the third blades are divided into two portions and disposed on both sides of the fourth blades, x and y being positive integers, and the sum of x and y being equal to n.

[0070] In implementation, the plurality of blades in the first layer blade group can be disposed on a first layer circuit board, and the plurality of blades in the second layer blade group can be disposed on a second layer circuit board. The first layer blade group includes first blades and second blades, the average thickness of the first blades being greater than the average thickness of the second blades, i.e., the first blades are thick blades relative to the second blades, and the second blades are thin blades relative to the first blades. Similarly, the second layer blade group includes third blades and fourth blades, the average thickness of the third blades being greater than the average thickness of the fourth blades, i.e., the third blades are thick blades relative to the fourth blades, and the fourth blades are thin blades relative to the third blades.

[0071] As shown in Figure 1 , Figure 1 The first layer blade group 11 includes first blades (i.e., first thick blades 112) and second blades (i.e., first thin blades 111), and the second layer blade group 12 includes third blades (i.e., second thick blades 122) and fourth blades (i.e., second thin blades 121). The thickness of the first blades and the second blades can be set according to business needs, and the thickness of the third blades and the fourth blades can also be set according to business needs, which are not specifically limited here.

[0072] As shown in Figure 1As shown, this application takes into account the high-frequency adjustment range of the tumor target area corresponding to the middle region. In order to ensure the control precision of the blades, the first thin blade (i.e., the second type of blade) can be concentrated in the middle region of the first layer circuit board, and the first thick blade (i.e., the first type of blade) can be divided into two parts and set on both sides of the second type of blade. Similarly, the fourth type of blade can be concentrated in the middle region of the second layer circuit board, and the third type of blade can be divided into two parts (e.g., evenly divided into two parts) and set on both sides of the fourth type of blade, so as to ensure the accuracy of the multi-leaf grating structure through the precise control of the thick and thin blades.

[0073] In practice, the first-layer circuit board can be composed of multiple partial circuit boards, and the second-layer circuit board can also be composed of multiple partial circuit boards. The following explanation uses the first-layer circuit board as an example. (See [link to documentation]). Figure 3 The schematic diagram of the first-layer circuit board shown includes multiple local circuit boards, namely local circuit board one 131, local circuit board two 132, and local circuit board three 133. Local circuit board one 131 and local circuit board three 133 are located on both sides of local circuit board two 132. Thin blades can be concentrated on local circuit board two 132, while thick blades are evenly divided into two parts and disposed on local circuit board one 131 and local circuit board three 133 respectively. This arrangement allows for the use of different circuit boards for thin and thick blades. Subsequently, after any part of the blades is worn out, or after a design update of either the thin or thick blade, that part of the blades can be replaced or updated individually, reducing maintenance costs and improving maintenance convenience.

[0074] In this application, x and y are positive integers, and their values ​​can be set according to actual needs, with the sum of x and y being n. For example, when n is 37, x can be set to 20 and y can be set to 17, meaning that 17 thin blades are set in the middle area of ​​the first layer circuit, and 10 thick blades are set on each side of the thin blades. The isocenter position accuracy requirement for the middle area can be ±2.5mm, and the isocenter position accuracy requirement for the edge area can be ±5mm.

[0075] The blades in this application include both thick and thin blades. Due to limitations in sensor size and blade thickness, existing detection methods are difficult to apply to thin blades, making the detection of their distance and orientation challenging. To achieve detection of various blade types, especially thin blades, this application proposes a combination of magnetic beads and magnetic sensors. Changes in the magnetic field of the magnetic beads can be captured in real time by the magnetic sensors, which have an accuracy of ±0.01 mm. This is suitable for monitoring minute displacements of the blades, enabling relatively accurate detection of the movement direction and distance of thin blades.

[0076] In an optional embodiment, each of the vanes is provided with at least one magnetic bead, and target regions on the first layer of circuit boards and the second layer of circuit boards associated with the vanes are provided with a plurality of groups of magnetic sensors.

[0077] Each of the vanes is provided with at least one magnetic bead on a side associated with the circuit boards, and the material of the magnetic bead can be set as needed. Referring to Figure 3 As shown, the first layer of circuit boards is provided with a plurality of groups of magnetic sensors 134 on the partial circuit boards in the middle region, and the type of the magnetic sensors 134 can be set as needed, such as a Hall effect sensor. Figure 3 The magnetic sensors on the second layer of circuit boards are not shown. The setting positions of the magnetic sensors on the second layer of circuit boards can refer to the setting of the first layer of circuit boards, which will not be described in detail here. Through the above setting, the movement distance and the movement direction of the vanes can be accurately detected through the cooperation of the magnetic beads and the magnetic sensors.

[0078] In a specific implementation, the method further includes: determining a target movement direction and a target movement distance of the at least one vane according to driving encoder information corresponding to the driving motor; and determining a current movement direction and a current movement distance of the at least one vane according to the acquisition signals of the plurality of groups of magnetic sensors.

[0079] When the target movement direction and the current movement direction are consistent, and the deviation value between the target movement distance and the current movement distance is less than or equal to a set deviation threshold, first feedback information indicating that the movement accuracy of the two-layer vane group is qualified is generated.

[0080] When the target movement direction and the current movement direction are inconsistent, and / or the deviation value between the target movement distance and the current movement distance is greater than the set deviation threshold, second feedback information indicating that the movement of the two-layer vane group fails is generated, and an alarm information is triggered.

[0081] The driving motor corresponds to a driving encoder, and the target movement direction and the target movement distance of the driving motor driving the vanes to move can be determined according to the driving encoder information corresponding to the driving motor. The target movement direction and the target movement distance can be regarded as the reference movement direction and the reference movement distance of the vanes, and the position where the vanes should theoretically be located can be determined according to the target movement direction and the target movement distance.

[0082] In actual application, the connection between the driving motor and the blade can be loose, disconnected or low in precision, so that the actual position of the blade is inconsistent with the theoretical position. In order to avoid the problem that the radiation field formed by the blade is inaccurate due to the above-mentioned situation, the current moving direction and the current moving distance of at least one blade can be determined according to the signals collected by the plurality of groups of magnetic sensors, that is, the current moving direction and the current moving distance can be regarded as the actual moving direction and distance of the blade, so as to determine the actual position of the blade according to the current moving direction and the current moving distance of at least one blade.

[0083] Further, it is judged whether the target moving direction is consistent with the current moving direction, and the deviation value between the target moving distance and the current moving distance is judged. According to the judgment of the moving direction and the distance deviation value, it is determined whether the actual moving process of the blade is consistent with the reference moving process (i.e. the theoretical moving process) of the blade driven by the driving motor.

[0084] When it is determined that the target moving direction is consistent with the current moving direction, and the deviation value between the target moving distance and the current moving distance is less than or equal to the set deviation threshold, it is determined that the moving processes of the two are consistent, and therefore the first feedback information indicating that the moving precision of the two-layer blade group is qualified is generated.

[0085] On the contrary, when the target moving direction is inconsistent with the current moving direction, and / or the deviation value between the target moving distance and the current moving distance is greater than the set deviation threshold, it is determined that the moving processes of the two are inconsistent, and there is a large error, so the second feedback information indicating that the two-layer blade group moves fails is generated, and an alarm information is triggered, so that the multi-leaf collimator structure can be detected and repaired according to the alarm information in the future, so as to ensure the accuracy of the multi-leaf collimator structure.

[0086] In implementation, after the alarm information is triggered, the fault module can be determined and repaired or replaced. Since the multi-leaf collimator structure of the present application is modularized, the fault module can be replaced separately after the fault module is determined. For example, when the locking detection module has a problem, the power is turned off, the detection module locking screw is loosened, the problem module is pulled out and a new module is inserted, and after recalibration, the operation is resumed; when the locking driving motor, screw rod and nut have a problem, the power is turned off, the motor locking screw is loosened, the problem component is pulled out and replaced, and after recalibration, the operation is resumed.

[0087] The application detects the actual position of the leaf by the magnetic sensor and the reference position of the leaf by the motor encoder, so that the detection of the magnetic sensor and the motor encoder forms a closed-loop control, realizes a two-level feedback mechanism for the multi-leaf collimator structure, monitors the cooperative movement of the motor and the leaf in real time, ensures the movement accuracy of the leaf, and guarantees the accuracy of the multi-leaf collimator structure.

[0088] In the related art, a single sensor (such as an encoder or a potentiometer) is used to detect the position of the leaf, and the detection method is relatively single, which is easily affected by electromagnetic interference, mechanical wear or temperature drift, resulting in leaf position error, especially in 2.5mm thin leaf, the error may exceed the clinical allowable range; while using high-precision optical detection technology (such as CCD imaging), although the accuracy requirement can be met, the device cost is high, the optical path debugging is complex, and the calibration frequency increases in long-term use due to the influence of the radiation environment, resulting in high maintenance cost.

[0089] Compared with the above related art, the application realizes a two-level feedback mechanism for the leaf position by using the cooperative action of the motor encoder, the magnetic beads and the magnetic sensor, optimizes the leaf layering structure and multi-source detection fusion, realizes high-precision monitoring and dynamic correction of the leaf position, reduces the cost, improves the maintenance convenience, and finally optimizes the radiation beam shaping effect.

[0090] The following describes an implementation of determining the current moving direction and the current moving distance of the leaf by using multiple magnetic sensors.

[0091] In an optional implementation, one side of the target leaf connected with the target circuit board is provided with multiple grooves, and multiple magnetic beads are arranged in each groove according to a first target interval; there is a leaf protruding area between adjacent two grooves; the target area of the target circuit board connected with the target leaf is provided with four groups of magnetic sensors, and the first group of magnetic sensors, the second group of magnetic sensors, the third group of magnetic sensors and the fourth group of magnetic sensors are arranged in sequence in the moving direction of the target leaf; wherein when the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board, and when the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board.

[0092] The diameter of the magnetic bead is the same as the width of the magnetic sensor, the first target interval is a multiple of the diameter of the magnetic bead, and the width of the leaf protruding area is 2 times the first target interval minus the difference of the diameter of the magnetic bead.

[0093] The target leaf can be a leaf in the first layer leaf group or a leaf in the second layer leaf group, the target circuit board is a first layer circuit board when the target leaf is a leaf in the first layer leaf group, and the target circuit board is a second layer circuit board when the target leaf is a leaf in the second layer leaf group.

[0094] Referring to Figure 4 Fig. 1 is a schematic view of the relative position of the magnetic beads and the blade, and the side of the blade connected to the target circuit board is provided with a plurality of grooves, and there is a blade protrusion area 42 between adjacent two grooves; wherein a plurality of magnetic beads 41 are arranged in each groove according to a first target interval.

[0095] According to Figure 3 It can be seen that the target area of the target circuit board connected to the target blade is provided with four groups of magnetic sensors, i.e. the first group of magnetic sensors, the second group of magnetic sensors, the third group of magnetic sensors and the fourth group of magnetic sensors; and the first group of magnetic sensors, the second group of magnetic sensors, the third group of magnetic sensors and the fourth group of magnetic sensors are arranged in sequence in the movement direction of the target blade, as shown by the four groups of magnetic sensors in the dashed box in Fig. 2. Figure 3

[0096] In order to realize more accurate measurement of the moving direction and distance of the blade, there are specific requirements between the diameter of the magnetic beads, the width of the magnetic sensor, the first target interval and the like. For example, the width of the magnetic sensor is the same as the diameter of the magnetic bead, the first target interval can be a multiple of the diameter of the magnetic bead, and the width of the blade protrusion area is 2 times the first target interval minus the difference of the diameter of the magnetic bead.

[0097] For example, if the diameter of the magnetic bead is 1mm, the width of the magnetic sensor can be 1mm, and the first target interval can be a multiple of the diameter of the magnetic bead, such as 3 times, i.e. the first target interval is 3mm, and the width of the blade protrusion area can be 5mm. If the first target interval is 4mm, the width of the blade protrusion area can be 7mm.

[0098] Based on the above settings, the present application can include the following steps according to the acquisition signals of the plurality of groups of magnetic sensors to determine the current moving direction and the current moving distance of the at least one blade:

[0099] Step a1, continuously detecting the acquisition signals of the four groups of magnetic sensors corresponding to the blade during the movement of the blade;

[0100] Step a2, performing AND operation on the acquisition signals of the first group of magnetic sensors and the fourth group of magnetic sensors to obtain a first level signal, and performing AND operation on the acquisition signals of the second group of magnetic sensors and the third group of magnetic sensors to obtain a second level signal;

[0101] Step a3, determining the current moving direction of the blade according to the combination transformation state of the first level signal and the second level signal;

[0102] Step a4, determining the current moving distance of the blade according to the signal change state of the first level signal.​

[0103] In practice, the signals from four sets of magnetic sensors corresponding to the blade can be continuously detected during the blade's movement. When the magnetic bead passes the magnetic sensors, the sensor's signal changes from 1 to 0. The signals from the first and fourth sets of magnetic sensors are then ANDed to obtain a first-level signal, and the signals from the second and third sets of magnetic sensors are ANDed to obtain a second-level signal. The current direction of blade movement can then be determined based on the continuous combination of the first and second-level signals. Furthermore, the current distance traveled by the blade can be determined based on the signal changes of the first-level signal.

[0104] See Figure 5 As shown, in conjunction with this Figure 5 The determination of the current direction and distance of movement of the blade is illustrated by an example. Figure 5 The display shows multiple magnetic beads, multiple sets of magnetic sensors, and the blade protrusion area (i.e., Figure 5 (As shown in the orange rectangle), Bit0 represents the second level signal, and Bit1 represents the first level signal. When the blade runs in the indicated blade direction, the movement of the magnetic bead causes the combined state of Bit1 and Bit0 to change as follows: 01-10-00-00-00-00-01-10-00-00-00-00, etc. Therefore, if the combined state changes according to "01-10-00-…-01…", it indicates that the blade is running in the indicated direction. Figure 5 The movement shown indicates that the blade is extending and moving towards the center. If the combined state changes according to "01-00-...-10-01...", it indicates that the blade is moving in the opposite direction as shown in the diagram, that is, the blade is retracting and moving towards the initial zero position. Specifically, if the current state is 01, the next state change being 10 indicates the blade is extending, and the next state change being 00 indicates the blade is retracting; if the current state is 00, the next state change being 01 indicates the blade is extending, and the next state change being 10 indicates the blade is retracting; if the current state is 10, the next state change being 00 indicates the blade is extending, and the next state change being 01 indicates the blade is retracting.

[0105] And each time Bit1 detects a high-level rising edge change, that is, a change from 0 to 1, it indicates that the blade has actually completed a first target spacing.

[0106] This application employs a dual-magnetic-sensor parallel detection method to avoid the problem of single-sensor detection failure of magnetic beads; simultaneously, four sets of magnetic sensors are set, with two magnetic sensors in each set. Figure 5The detection results of the magnetic sensor group with reference number 1 and the magnetic sensor group with reference number 4 are subjected to an AND operation, and the detection result of bit1 is output. The detection results of the magnetic sensor group with reference number 2 and the magnetic sensor group with reference number 3 are subjected to an AND operation, and the detection result of bit0 is output. Through the above design, the problem of non-continuous arrangement of magnetic beads can be solved in the case of non-continuous grooving of the leaf, that is, there is a convex region of the leaf, and the moving direction and moving distance of the leaf can be monitored. Since the magnetic beads cannot be arranged continuously and equidistantly, the application calculates the running distance of the leaf by using the detection result of bit1. Taking the magnetic bead spacing (i.e., the first target spacing) of 3mm as an example, bit1 identifies a high-level rising edge change once, which indicates that the magnetic sensor detects a new magnetic bead, that is, the leaf actually runs the spacing of two magnetic beads, i.e., 3mm.

[0107] Through the above design, the magnetic beads are arranged in the non-continuous grooves on the leaf, so that the leaf can meet the rigidity requirement, and the position of the leaf can be accurately measured by using multiple groups of magnetic sensors and magnetic beads in the case of non-continuous grooving.

[0108] In the related art, the leaf monitoring of the multi-leaf collimator structure depends on a single sensor (such as an encoder or a potentiometer), and the monitoring process is easily affected by electromagnetic interference, mechanical wear or temperature drift, resulting in a large error of the leaf position, especially in a 2.5mm-level thin leaf, the error may exceed the clinically allowed range, reducing the accuracy of the multi-leaf collimator structure. In the application, the magnetic sensor and the motor encoder are fused for detection, that is, the magnetic beads and the magnetic sensor are used to detect the actual moving direction and moving distance of the leaf, and the motor encoder is used to detect the theoretical moving direction and moving distance of the leaf, so as to ensure the accuracy of the multi-leaf collimator structure. Combined with the differential accuracy control of the layered leaf, the isocenter accuracy of the thin leaf can be within ±2.5mm, meeting the conformal requirements of complex target regions. At the same time, the use of the non-contact detection scheme of the magnetic sensor can reduce the overall cost and prolong the service life of the multi-leaf collimator structure while ensuring the accuracy.

[0109] In another optional embodiment, one side of the target leaf connected to the target circuit board is provided with a groove, and a magnetic bead is arranged in the groove. A plurality of groups of magnetic sensors are continuously arranged on a target area of the target circuit board connected to the target leaf. When the target leaf is a leaf in a first layer leaf group, the target circuit board is a first layer circuit board, and when the target leaf is a leaf in a second layer leaf group, the target circuit board is a second layer circuit board.

[0110] Reference is made to Figure 6As shown, the side of the blade connected with the target circuit board is provided with a groove, and a magnetic bead 41 is arranged in the groove. Since only one magnetic bead is arranged, a plurality of groups of magnetic sensors are arranged in succession on the target area of the target circuit board connected with the target blade, and the coverage length of the plurality of groups of magnetic sensors needs to be set to be relatively long, so as to be able to detect the moving distance of the blade. For example, on the target area of the target circuit board, the plurality of groups of magnetic sensors can cover the target area at a set interval along the moving direction of the blade.

[0111] Based on the above arrangement, the current moving direction and the current moving distance of the at least one blade according to the acquisition signals of the plurality of groups of magnetic sensors can include: continuously detecting the acquisition signals of the plurality of groups of magnetic sensors corresponding to the blade during the movement of the blade; and determining the current moving direction and the current moving distance of the blade according to the signal change state of the acquisition signals of the plurality of groups of magnetic sensors.

[0112] In practice, the acquisition signals of the plurality of groups of magnetic sensors corresponding to the blade are continuously detected during the movement of the blade. Different magnetic sensors are inducted during the movement of the blade to the center position (forward movement) or the mechanical zero position (backward movement), so that the actual running position and the running direction of the blade can be identified through the change of the acquisition signals of the magnetic sensors.

[0113] When the magnetic bead moves, the magnetic sensor is inducted, and the acquisition signal of the magnetic sensor changes, such as changing from 1 to 0. The current moving direction of the blade can be determined according to the change of the acquisition signals of the plurality of groups of magnetic sensors. Referring to Figure 7 As shown, the acquisition signal of the magnetic sensor with the mark 4 changes from 1 to 0, and after a period of time, the acquisition signal of the magnetic sensor with the mark 3 changes from 1 to 0, indicating that the blade moves along the direction of the blade movement shown in Figure 7 As shown, the acquisition signal of the magnetic sensor with the mark 4 changes from 1 to 0, and after a period of time, the acquisition signal of the magnetic sensor with the mark 3 changes from 1 to 0, indicating that the blade moves along the direction of the blade movement shown in Figure 7 As shown, the acquisition signal of the magnetic sensor with the mark 4 changes from 1 to 0, and after a period of time, the acquisition signal of the magnetic sensor with the mark 3 changes from 1 to 0, indicating that the blade moves along the direction of the blade movement shown in

[0114] After the interval of the plurality of groups of magnetic sensors and the width of the magnetic sensor are determined, the current moving distance of the blade can be determined according to the change of the acquisition signals of different groups of magnetic sensors. Assuming that the interval between the adjacent groups of magnetic sensors is 3 mm, and the width of the magnetic sensor is 1 mm, the acquisition signal of the magnetic sensor with the mark 4 changes from 1 to 0, and after a period of time, the acquisition signal of the magnetic sensor with the mark 3 changes from 1 to 0, at this time, the moving distance of the magnetic bead is the sum of 2 times the width of the magnetic sensor and the interval between the two groups of magnetic sensors, that is, 5 mm.

[0115] In practice, the blade's operational accuracy is determined by the spacing of the magnetic sensors. Figure 7 As shown in the example, assuming the width of the magnetic sensor is 1mm and there is no gap between different groups of magnetic sensors, therefore... Figure 7 The distance between different groups of magnetic sensors is 2mm, and there are 4 groups of magnetic sensors arranged at equal intervals in the same blade channel. When the blade is in the initial zero position, no magnetic sensor is sensed. As the blade moves towards the center (forward), multiple magnetic sensors change from 0 to 1 in sequence. When the red second group of magnetic sensors is sensed, it means that the magnetic bead has passed the second group of sensors, which means that the blade has moved a distance of 3×2mm.

[0116] The above process allows for a simpler and more accurate determination of the blade's direction and distance of movement.

[0117] In another optional embodiment, a groove is provided on the side of the target blade connected to the target circuit board. Multiple magnetic beads are arranged in the groove according to a second target spacing. Two sets of magnetic sensors are provided on the target area of ​​the target circuit board connected to the target blade. The first set of magnetic sensors and the second set of magnetic sensors are arranged sequentially along the direction of movement of the target blade. When the target blade is a blade in the first layer of blade groups, the target circuit board is a first-layer circuit board; when the target blade is a blade in the second layer of blade groups, the target circuit board is a second-layer circuit board. The diameter of the magnetic beads is the same as the width of the magnetic sensors, and the second target spacing is a multiple of the diameter of the magnetic beads.

[0118] See Figure 8 As shown, a groove is provided on the side of the target blade that is connected to the target circuit board. Multiple magnetic beads 41 are arranged in the groove according to a second target spacing, which can be set as needed. Two sets of magnetic sensors are provided on the target area of ​​the target circuit board connected to the target blade. The first and second sets of magnetic sensors are arranged sequentially along the direction of movement of the target blade, so as to use the two sets of sensors to detect the direction and distance of movement of the blade.

[0119] In practice, the diameter of the magnetic bead is the same as the width of the magnetic sensor, and the spacing between the second targets can be a multiple of the diameter of the magnetic bead. For example, the diameter of the magnetic bead and the width of the magnetic sensor can be 1 mm, and the diameter of the second target can be 3 mm, etc.

[0120] Based on the above setting, the application determines the current moving direction and the current moving distance of the at least one leaf according to the collected signals of the plurality of groups of magnetic sensors, which can include: continuously detecting the collected signals of the two groups of magnetic sensors corresponding to the leaf during the movement of the leaf; determining the current moving direction of the leaf according to the signal change state of the collected signals of the two groups of magnetic sensors, and determining the current moving distance of the leaf according to the signal change state of any one of the two groups of magnetic sensors.

[0121] During the movement of the leaf, the collected signals of the two groups of magnetic sensors corresponding to the leaf are continuously detected. Figure 9 As shown in the figure, the magnetic sensor group with the label 1 corresponds to Bit1, and the magnetic sensor group with the label 2 corresponds to Bit0. When the signal change state of the collected signals of the two groups of magnetic sensors is “01-10-00-…-01……”, it indicates that the leaf is moving in the direction shown in the figure. If the combination change state changes as “10-01-00-…-10-01……”, it indicates that the leaf is moving in the opposite direction shown in the figure.

[0122] And the moving distance of the leaf can be determined according to the signal change state of any one of the two groups of magnetic sensors. Taking the magnetic sensor with the label 1 as an example, when Bit1 identifies a high-level rising edge change, i.e., detects a change from 0 to 1, it indicates that the magnetic sensor has detected a new magnetic bead, which means that the leaf has actually run the interval of two magnetic beads, i.e., the second target interval. Figure 9

[0123] The application realizes the monitoring of the current moving direction and the current moving distance of the leaf through the above process, so as to ensure the accuracy of the multi-leaf collimator.

[0124] The multi-leaf collimator structure in the application can be modularly designed and integrated, such as integrating the detection module and the leaf group, supporting quick disassembly and replacement, such as circuit board standardized interface design, which can reduce maintenance difficulty and shorten downtime. Through modular design, the replacement time of the detection unit can be shortened, the device availability can be improved, and the maintenance of the multi-leaf collimator structure is more convenient.

[0125] The above control method of the application is applied to a layered multi-leaf collimator structure, which includes two leaf groups, each leaf group includes thick leaves and thin leaves, and the thin leaves are located in the middle region, the accuracy of which can reach 2.5mm, and the thick leaves are located on both sides of the thin leaves, the accuracy of which can reach 5mm. Through the design of the two leaf groups, the design of the thin leaves and the thick leaves, and the accurate control of the multi-leaf collimator structure, the leakage rate and the half-shadow width can be reduced, the normal tissue dose can be reduced, and the accuracy of the multi-leaf collimator structure can be improved.

[0126] ​Meanwhile, the motor encoder and the magnetic sensor detection are combined to realize the closed-loop control of the blade position, so that the movement process of the blade is more accurate, and the blade precision is improved to 2.5mm (thin blade) and 5mm (thick blade). In addition, the multi-leaf collimator structure can be designed in a modular manner to reduce maintenance costs and be suitable for high-precision radiotherapy scenarios.

[0127] The application also provides a multi-leaf collimator structure of a linear accelerator, comprising two layers of leaf groups, the first layer of leaf groups comprising n leaves, and the second layer of leaf groups comprising n+1 leaves, the first layer of leaf groups being located above the second layer of leaf groups, and the leaves in the two layers of leaf groups being staggered, the first layer of leaf groups comprising a plurality of leaves with different thicknesses, the second layer of leaf groups comprising a plurality of leaves with different thicknesses, and n being a positive integer; wherein the leaves in the two layers of leaf groups are controlled by the control method of the multi-leaf collimator.

[0128] In an optional embodiment, the plurality of leaves in the first layer of leaf groups are arranged on a first layer of circuit boards, and the plurality of leaves in the second layer of leaf groups are arranged on a second layer of circuit boards.

[0129] The first layer of leaf groups comprises x first leaves and y second leaves, the average thickness of the first leaves being greater than the average thickness of the second leaves; the second layer of leaf groups comprises x+2 third leaves and y-1 fourth leaves, the average thickness of the third leaves being greater than the average thickness of the fourth leaves.

[0130] The second leaves are arranged in the middle region of the first layer of circuit boards, and the first leaves are divided into two parts and arranged on both sides of the second leaves; the fourth leaves are arranged in the middle region of the second layer of circuit boards, and the third leaves are divided into two parts and arranged on both sides of the fourth leaves, x and y being positive integers, and the sum of x and y being equal to n.

[0131] In an optional embodiment, each leaf is provided with at least one magnetic bead, and a target region connected to the leaf on the first layer of circuit boards and the second layer of circuit boards is provided with a plurality of groups of magnetic sensors.

[0132] In an alternative embodiment, the side of the target leaf connected to the target circuit board is provided with a plurality of grooves, and a plurality of magnetic beads are arranged in each groove according to a first target interval. There is a leaf protrusion region between adjacent two grooves. The target region of the target circuit board connected to the target leaf is provided with four groups of magnetic sensors, and the first group of magnetic sensors, the second group of magnetic sensors, the third group of magnetic sensors, and the fourth group of magnetic sensors are arranged in sequence in the movement direction of the target leaf. When the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board. When the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board.

[0133] The diameter of the magnetic bead is the same as the width of the magnetic sensor, the first target interval is a multiple of the diameter of the magnetic bead, and the width of the leaf protrusion region is 2 times the first target interval minus the difference between the diameter of the magnetic bead.

[0134] In an alternative embodiment, the side of the target leaf connected to the target circuit board is provided with a groove, and a magnetic bead is arranged in the groove. The target region of the target circuit board connected to the target leaf is continuously provided with a plurality of groups of magnetic sensors. When the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board. When the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board.

[0135] In an alternative embodiment, the side of the target leaf connected to the target circuit board is provided with a groove, and a plurality of magnetic beads are arranged in the groove according to a second target interval. The target region of the target circuit board connected to the target leaf is provided with two groups of magnetic sensors, and the first group of magnetic sensors and the second group of magnetic sensors are arranged in sequence in the movement direction of the target leaf. When the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board. When the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board. The diameter of the magnetic bead is the same as the width of the magnetic sensor, and the second target interval is a multiple of the diameter of the magnetic bead.

[0136] Corresponding to the above-mentioned embodiments of the control method of the multi-leaf collimator, the application also provides embodiments of the control device of the multi-leaf collimator. Figure 10 The schematic diagram of the control device of the multi-leaf collimator provided by the application is applied to a layered multi-leaf collimator structure. The layered multi-leaf collimator structure includes two leaf groups. The first layer leaf group includes n leaves, and the second layer leaf group includes n+1 leaves. The first layer leaf group is located above the second layer leaf group, and the leaves in the two leaf groups are staggered. The first layer leaf group includes a plurality of leaves with different thicknesses, the second layer leaf group includes a plurality of leaves with different thicknesses, and n is a positive integer. The device specifically includes:

[0137] The acquisition module 701 is configured to acquire blade control signals in multiple control periods, the blade control signals including control signals corresponding to multiple blades in the first layer blade group and the second layer blade group respectively;

[0138] The control module 702 is configured to, in each control period, control a driving motor corresponding to at least one blade in the two-layer blade group to rotate in response to the blade control signals, so as to drive the blade controlled by the driving motor to move a target moving distance in a target moving direction by using the rotation of the driving motor, so that the two-layer blade group forms an irregular shape radiation field.

[0139] In an optional implementation, the multiple blades in the first layer blade group are arranged on a first layer circuit board, and the multiple blades in the second layer blade group are arranged on a second layer circuit board.

[0140] The first layer blade group includes x first blades and y second blades, and the average thickness of the first blades is greater than the average thickness of the second blades; the second layer blade group includes x+2 third blades and y-1 fourth blades, and the average thickness of the third blades is greater than the average thickness of the fourth blades.

[0141] The second blades are arranged in a central region of the first layer circuit board, the first blades are divided into two parts and arranged on both sides of the second blades, the fourth blades are arranged in a central region of the second layer circuit board, and the third blades are divided into two parts and arranged on both sides of the fourth blades, x and y are positive integers, and the sum of x and y is equal to n.

[0142] In an optional implementation, each blade is provided with at least one magnetic bead, and a target region connected with the blade on the first layer circuit board and the second layer circuit board is provided with multiple groups of magnetic sensors; the device further includes a feedback module 703 configured to:

[0143] determine the target moving direction and the target moving distance of the at least one blade according to driving encoder information corresponding to the driving motor, and determine the current moving direction and the current moving distance of the at least one blade according to acquisition signals of the multiple groups of magnetic sensors;

[0144] when the target moving direction is consistent with the current moving direction, and the deviation value between the target moving distance and the current moving distance is less than or equal to a set deviation threshold value, generate first feedback information for indicating that the moving accuracy of the two-layer blade group is qualified.

[0145] In an alternative embodiment, the feedback module 703 further comprises:

[0146] When the target moving direction and the current moving direction are inconsistent, and / or the deviation value between the target moving distance and the current moving distance is greater than the set deviation threshold, second feedback information indicating that the two-layer leaf group moves fails is generated, and an alarm information is triggered.

[0147] In an alternative embodiment, one side of the target leaf connected with the target circuit board is provided with a plurality of grooves, and a plurality of magnetic beads are arranged in each groove according to a first target interval. There is a leaf protrusion area between adjacent two grooves. The target area of the target circuit board connected with the target leaf is provided with four groups of magnetic sensors, and the first group of magnetic sensors, the second group of magnetic sensors, the third group of magnetic sensors and the fourth group of magnetic sensors are arranged in sequence in the movement direction of the target leaf. Wherein, when the target leaf is a leaf in the first layer leaf group, the target circuit board is a first layer circuit board, and when the target leaf is a leaf in the second layer leaf group, the target circuit board is a second layer circuit board.

[0148] Wherein the diameter of the magnetic bead is the same as the width of the magnetic sensor, the first target interval is a multiple of the diameter of the magnetic bead, and the width of the leaf protrusion area is 2 times the first target interval minus the difference of the diameter of the magnetic bead.

[0149] The feedback module 703, when determining the current moving direction and the current moving distance of the at least one leaf according to the acquisition signals of the plurality of groups of magnetic sensors, is configured to:

[0150] Continuously detecting the acquisition signals of the four groups of magnetic sensors corresponding to the leaf during the movement of the leaf;

[0151] Performing AND operation on the acquisition signals of the first group of magnetic sensors and the fourth group of magnetic sensors to obtain a first level signal, and performing AND operation on the acquisition signals of the second group of magnetic sensors and the third group of magnetic sensors to obtain a second level signal;

[0152] According to the combination transformation state of the first level signal and the second level signal, the current moving direction of the leaf is determined.

[0153] According to the signal change state of the first level signal, the current moving distance of the leaf is determined.

[0154] In an alternative embodiment, the side of the target leaf blade connected to the target circuit board is provided with a groove, and a magnetic bead is arranged in the groove. The target region of the target circuit board connected to the target leaf blade is continuously provided with a plurality of groups of magnetic sensors. When the target leaf blade is a leaf blade in a first layer of leaf blade group, the target circuit board is a first layer of circuit board. When the target leaf blade is a leaf blade in a second layer of leaf blade group, the target circuit board is a second layer of circuit board.

[0155] The feedback module 703 is configured to determine the current moving direction and the current moving distance of the at least one leaf blade according to the acquisition signals of the plurality of groups of magnetic sensors.

[0156] The acquisition signals of the plurality of groups of magnetic sensors corresponding to the leaf blade are continuously detected during the movement of the leaf blade.

[0157] The current moving direction and the current moving distance of the leaf blade are determined according to the signal change state of the acquisition signals of the plurality of groups of magnetic sensors.

[0158] In an alternative embodiment, the side of the target leaf blade connected to the target circuit board is provided with a groove, and a plurality of magnetic beads are arranged in the groove according to a second target interval. The target region of the target circuit board connected to the target leaf blade is provided with two groups of magnetic sensors, and the first group of magnetic sensors and the second group of magnetic sensors are arranged in sequence in the moving direction of the target leaf blade. When the target leaf blade is a leaf blade in a first layer of leaf blade group, the target circuit board is a first layer of circuit board. When the target leaf blade is a leaf blade in a second layer of leaf blade group, the target circuit board is a second layer of circuit board. The diameter of the magnetic bead is the same as the width of the magnetic sensor, and the second target interval is a multiple of the diameter of the magnetic bead.

[0159] The feedback module 703 is configured to determine the current moving direction and the current moving distance of the at least one leaf blade according to the acquisition signals of the plurality of groups of magnetic sensors.

[0160] The acquisition signals of the two groups of magnetic sensors corresponding to the leaf blade are continuously detected during the movement of the leaf blade.

[0161] The current moving direction of the leaf blade is determined according to the signal change state of the acquisition signals of the two groups of magnetic sensors, and the current moving distance of the leaf blade is determined according to the signal change state of any one of the two groups of magnetic sensors.

[0162] The functions and effects of the above-mentioned device are realized in the implementation process of the corresponding steps in the above-mentioned method, which will not be described here.

[0163] For the apparatus embodiment, since it basically corresponds to the method embodiment, the relevant part can be seen from the part of the method embodiment. The apparatus embodiment described above is only illustrative, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purpose of the application according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0164] The application further provides a computer readable storage medium, which stores a computer program, and the computer program can be used to execute the control method of the multi-leaf collimator described in the above embodiments.

[0165] The application further provides a computer device, which refers to Figure 11 The computer device provided by the application has the structure shown in the figure, and at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and of course, it can also include other hardware required by the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs to realize the control method of the multi-leaf collimator described in the above embodiments. Of course, in addition to the software implementation, the present specification does not exclude other implementation manners, such as logic devices or a combination of software and hardware, and so on, that is, the execution subject of the following processing flow is not limited to the logical unit, but can also be hardware or a logic device.

[0166] Those skilled in the art should understand that the embodiments of the application can be provided as a method, device, or computer program product. Therefore, the application can adopt a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the application can adopt the form of a computer program product implemented on one or more computer usable storage media containing computer usable program code (including but not limited to disk storage, CD-ROM, optical storage, etc.).

[0167] The application is described with reference to the flowcharts and / or block diagrams according to the method, device (system), and computer program product of the embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a machine that implements the flowcharts and / or block diagrams. Figure 1one or more processes and / or blocks Figure 1 an apparatus with the functionality to achieve the functionality specified in the flow

[0168] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flow Figure 1 one or more processes and / or blocks Figure 1 an apparatus with the functionality to achieve the functionality specified in the flow

[0169] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 one or more processes and / or blocks Figure 1 an apparatus with the functionality to achieve the functionality specified in the flow

[0170] The memory can include non-persistent memory and / or volatile memory, such as random access memory (RAM) about which the processor modifies. The memory is an example of computer readable media.

[0171] Computer readable media includes permanent and non-permanent, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital versatile disc (DVD), or other optical storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to computing devices. According to the definition herein, computer readable media does not include transitory media, such as modulated data signals and carrier waves.

[0172] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0173] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0174] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0175] The embodiments of the subject matter and functional operation described in this specification can be implemented in the following ways: digital electronic circuits, tangibly embodied computer software or firmware, computer hardware including the structures disclosed in this specification and their structural equivalents, or combinations thereof. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible, non-transitory program carrier for execution by a data processing apparatus or for controlling the operation of a data processing apparatus. Alternatively or additionally, the program instructions may be encoded on artificially generated propagation signals, such as machine-generated electrical, optical, or electromagnetic signals, which are generated to encode information and transmit it to a suitable receiving device for execution by the data processing apparatus. The computer storage medium may be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or combinations thereof.

[0176] The processes and logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit), and / or by programmable data processing apparatuses, which can be portion of hardware processing circuitry that executes specific tasks as described. Apparatuses can also be implemented as a combination of special purpose logic circuitry, e.g., an FPGA or an ASIC, and / or one or more programmable data processing apparatuses.

[0177] Computers suitable for the execution of a computer program include, by way of example, general and / or special purpose microprocessors, or any other kind of central processing unit. Generally, a central processing unit will receive instructions and data from a read-only memory and / or a random access memory. The essential elements of a computer are a central processing unit for performing or executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few.

[0178] Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0179] While this specification contains many specifics, these should not be construed as limitations on the scope of any invention or on the required scope of patent protection. Certain features that are described in this specification in the context of separate embodiments also can be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment also can be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features can be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination and the claimed combination can be directed to a subcombination or variation of a subcombination.

[0180] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all illustrated operations to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0181] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings are not necessarily shown in a specific order or sequence to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.

[0182] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of controlling a multi-leaf collimator, characterized by, The method is applied to a layered multi-leaf grating structure, wherein the layered multi-leaf grating structure includes two layers of leaf groups. The first layer of leaf groups includes n leaf groups, and the second layer of leaf groups includes n+1 leaf groups. The first layer of leaf groups is located above the second layer of leaf groups, and the leaf groups in the two layers of leaf groups are arranged alternately. The first layer of leaf groups includes various types of leaf groups with different thicknesses, and the second layer of leaf groups includes various types of leaf groups with different thicknesses, where n is a positive integer. Acquire blade control signals under multiple control cycles, wherein the blade control signals include control signals corresponding to various blades in the first layer blade group and the second layer blade group respectively; In each control cycle, in response to the blade control signal, the drive motor corresponding to at least one blade in the two-layer blade group is controlled to rotate; The rotation of the drive motor drives the blades controlled by the drive motor to move a target distance in the target direction, so that the two layers of blades form an irregularly shaped radiation field. In this configuration, multiple blades in the first layer of the blade group are disposed on the first layer of the circuit board, and multiple blades in the second layer of the blade group are disposed on the second layer of the circuit board. The first layer of blades includes x first-type blades and y second-type blades, with the average thickness of the first-type blades being greater than the average thickness of the second-type blades; the second layer of blades includes x+2 third-type blades and y-1 fourth-type blades, with the average thickness of the third-type blades being greater than the average thickness of the fourth-type blades. The second type of blade is concentrated in the middle area of ​​the first layer circuit board. The first type of blade is divided into two parts and disposed on both sides of the second type of blade. The fourth type of blade is concentrated in the middle area of ​​the second layer circuit board. The third type of blade is divided into two parts and disposed on both sides of the fourth type of blade. x and y are positive integers, and the sum of x and y equals n. Each blade is provided with at least one magnetic bead. Multiple sets of magnetic sensors are disposed on the first layer circuit board and the second layer circuit board in the target area connected to the blade. The method further includes: Based on the drive encoder information corresponding to the drive motor, the target moving direction and target moving distance of the at least one blade are determined; and based on the acquired signals of the multiple sets of magnetic sensor groups, the current moving direction and current moving distance of the at least one blade are determined. When the target moving direction and the current moving direction are consistent, and the deviation between the target moving distance and the current moving distance is less than or equal to a set deviation threshold, first feedback information is generated to indicate that the moving accuracy of the two-layer blade group is qualified.

2. The method of claim 1, wherein, The method further includes: When the target movement direction and the current movement direction are inconsistent, and / or the deviation between the target movement distance and the current movement distance is greater than the set deviation threshold, a second feedback message is generated to indicate a movement fault in the two-layer blade group, and an alarm message is triggered.

3. The method according to claim 1, characterized in that, Multiple grooves are provided on the side of the target blade that is connected to the target circuit board. Multiple magnetic beads are arranged in each groove according to the first target spacing. There is a blade protrusion area between two adjacent grooves. Four sets of magnetic sensors are provided on the target area of ​​the target circuit board that is connected to the target blade. The first set of magnetic sensors, the second set of magnetic sensors, the third set of magnetic sensors, and the fourth set of magnetic sensors are arranged in sequence along the movement direction of the target blade. When the target blade is a blade in the first layer of blade group, the target circuit board is the first layer of circuit board. When the target blade is a blade in the second layer of blade group, the target circuit board is the second layer of circuit board. The diameter of the magnetic bead is the same as the width of the magnetic sensor, the first target spacing is a multiple of the diameter of the magnetic bead, and the width of the blade protrusion area is twice the first target spacing minus the diameter of the magnetic bead. Determining the current direction and distance of movement of at least one blade based on the signals collected by the multiple sets of magnetic sensor groups includes: During the movement of the blade, the signals collected by the four sets of magnetic sensors corresponding to the blade are continuously detected; The signals acquired by the first group of magnetic sensors and the fourth group of magnetic sensors are ANDed to obtain a first level signal, and the signals acquired by the second group of magnetic sensors and the third group of magnetic sensors are ANDed to obtain a second level signal. The current direction of movement of the blade is determined based on the combined change state of the first level signal and the second level signal; The current moving distance of the blade is determined based on the signal change state of the first level signal.

4. The method according to claim 1, characterized in that, A groove is provided on the side of the target blade that is connected to the target circuit board, and a magnetic bead is provided in the groove. Multiple sets of magnetic sensors are continuously provided on the target area of ​​the target circuit board that is connected to the target blade. When the target blade is a blade in the first layer of blade group, the target circuit board is the first layer of circuit board. When the target blade is a blade in the second layer of blade group, the target circuit board is the second layer of circuit board. Determining the current direction and distance of movement of at least one blade based on the signals collected by the multiple sets of magnetic sensor groups includes: During the movement of the blade, the signals collected by multiple sets of magnetic sensors corresponding to the blade are continuously detected; Based on the signal change status of the signals collected by the multiple sets of magnetic sensors, the current moving direction and current moving distance of the blade are determined.

5. The method according to claim 1, characterized in that, A groove is provided on the side of the target blade that is connected to the target circuit board. Multiple magnetic beads are arranged in the groove according to a second target spacing. Two sets of magnetic sensors are provided on the target area of ​​the target circuit board connected to the target blade. The first set of magnetic sensors and the second set of magnetic sensors are arranged sequentially along the direction of movement of the target blade. When the target blade is a blade in the first layer of blade groups, the target circuit board is a first-layer circuit board; when the target blade is a blade in the second layer of blade groups, the target circuit board is a second-layer circuit board. The diameter of the magnetic beads is the same as the width of the magnetic sensors, and the second target spacing is a multiple of the diameter of the magnetic beads. Determining the current direction and distance of movement of at least one blade based on the signals collected by the multiple sets of magnetic sensor groups includes: During the movement of the blade, the signals collected by the two sets of magnetic sensors corresponding to the blade are continuously detected; Based on the signal change status of the two sets of magnetic sensors, the current direction of movement of the blade is determined, and based on the signal change status of any one of the two sets of magnetic sensors, the current distance the blade moves is determined.

6. A multi-leaf grating structure for a linear accelerator, characterized in that, It includes two layers of blade groups. The first layer of blade groups includes n blades, and the second layer of blade groups includes n+1 blades. The first layer of blade groups is located above the second layer of blade groups, and the blades in the two layers of blade groups are arranged alternately. The first layer of blade groups includes various types of blades with different thicknesses, and the second layer of blade groups includes various types of blades with different thicknesses. n is a positive integer. The blades in the two-layer blade group are controlled using the control method of the multi-leaf grating as described in any one of claims 1-5.

7. A control device for a multi-leaf grating, characterized in that, An application is made to a layered multi-leaf grating structure, the layered multi-leaf grating structure comprising two layers of leaf groups, the first layer of leaf groups comprising n leaf groups, and the second layer of leaf groups comprising n+1 leaf groups. The first layer of leaf groups is located above the second layer of leaf groups, and the leaf groups in the two layers of leaf groups are arranged alternately. The first layer of leaf groups comprises various types of leaf groups with different thicknesses, and the second layer of leaf groups comprises various types of leaf groups with different thicknesses, where n is a positive integer; the device includes: The acquisition module is used to acquire blade control signals under multiple control cycles, wherein the blade control signals include control signals corresponding to various blades in the first layer blade group and the second layer blade group respectively; The control module is used to control the drive motor corresponding to at least one blade in the two-layer blade group to rotate in response to the blade control signal in each control cycle, so as to use the rotation of the drive motor to drive the blade controlled by the drive motor to move the target moving distance in the target moving direction, so that the two-layer blade group forms an irregularly shaped radiation field. In this configuration, multiple blades in the first layer of the blade group are disposed on the first layer of the circuit board, and multiple blades in the second layer of the blade group are disposed on the second layer of the circuit board. The first layer of blades includes x first-type blades and y second-type blades, with the average thickness of the first-type blades being greater than the average thickness of the second-type blades; the second layer of blades includes x+2 third-type blades and y-1 fourth-type blades, with the average thickness of the third-type blades being greater than the average thickness of the fourth-type blades. The second type of blade is concentrated in the middle area of ​​the first layer circuit board. The first type of blade is divided into two parts and disposed on both sides of the second type of blade. The fourth type of blade is concentrated in the middle area of ​​the second layer circuit board. The third type of blade is divided into two parts and disposed on both sides of the fourth type of blade. x and y are positive integers, and the sum of x and y is equal to n. Each blade is provided with at least one magnetic bead, and multiple sets of magnetic sensors are provided on the first and second circuit boards in the target area connected to the blade. The device further includes: a feedback module, used for: Based on the drive encoder information corresponding to the drive motor, the target moving direction and target moving distance of the at least one blade are determined; and based on the acquired signals of the multiple sets of magnetic sensor groups, the current moving direction and current moving distance of the at least one blade are determined. When the target moving direction and the current moving direction are consistent, and the deviation between the target moving distance and the current moving distance is less than or equal to a set deviation threshold, first feedback information is generated to indicate that the moving accuracy of the two-layer blade group is qualified.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by a processor, it implements the steps of the method according to any one of claims 1-5.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor performs the steps of the method according to any one of claims 1-5.

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