A rotational speed determination method, apparatus and device

Abstract

The application discloses a rotational speed determination method, device and equipment, and belongs to the field of radiotherapy. The rotational speed determination method comprises the following steps: acquiring dose data and leaf data of all sub-fields corresponding to each gantry angle; determining the irradiation sequence of each sub-field corresponding to each gantry angle and the rotational speed of each rotation of the gantry according to the dose data and the leaf data.

Description

Technical Field

[0001] This application belongs to the field of radiotherapy, specifically relating to a method, apparatus, and equipment for determining rotation speed. Background Technology

[0002] In traditional intensity modulation radiation therapy (IMRT), the planner can pre-set the gantry angle of the radiotherapy equipment, the beam corresponding to each gantry angle, and the subfields included in each beam. By adjusting the radiation dose of each subfield and moving the multi-leaf collimators (MLCs), radiotherapy to the tumor target area can be achieved more effectively and safely.

[0003] During gantry rotation, the radiation dose to each subfield will vary. To ensure that the expected radiation dose is achieved during gantry rotation, the maximum gantry speed is usually calculated based on the maximum radiation dose, and each subfield is irradiated at this speed. However, this results in a longer irradiation time for the subfield corresponding to the minimum radiation dose, thus leading to a longer irradiation time of the radiotherapy equipment on the tumor target area. Summary of the Invention

[0004] The purpose of this application is to provide a method, apparatus, and device for determining rotation speed, which can solve the problem of long irradiation time of radiotherapy equipment on tumor target areas.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application provide a method for determining rotational speed. The method includes: acquiring dose data and blade data for all subfields corresponding to each gantry angle; and determining, based on the dose data and blade data, the irradiation sequence of each subfield corresponding to each gantry angle and the rotational speed of the gantry per revolution.

[0007] Secondly, embodiments of this application provide a rotation speed determination device. The device includes an acquisition module and a determination module. The acquisition module is used to acquire dose data and blade data for all subfields corresponding to each gantry angle. The determination module is used to determine the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution based on the dose data and blade data acquired by the acquisition module.

[0008] Thirdly, embodiments of this application provide a medical device including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the method as described in the first aspect.

[0009] Fourthly, embodiments of this application provide a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method as described in the first aspect.

[0010] Fifthly, embodiments of this application provide a chip including a processor and a communication interface coupled to the processor, the processor being used to run programs or instructions to implement the method as described in the first aspect.

[0011] In this embodiment, dose data and blade data for all subfields corresponding to each gantry angle are first acquired. Then, based on this dose data and blade data, the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution are determined. This scheme optimizes the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution by using the dose data and blade data, resulting in a more uniform dose value for the subfields irradiated during each revolution of the gantry. This allows subfields requiring longer irradiation times to be completed in the first few revolutions, thereby increasing the gantry rotation speed over multiple revolutions and ultimately reducing the overall operating time of the radiotherapy equipment. Attached Figure Description

[0012] Figure 1 This is one of the flowcharts illustrating a method for determining rotational speed provided in an embodiment of this application;

[0013] Figure 2A This is a second schematic flowchart of a method for determining rotational speed provided in an embodiment of this application;

[0014] Figure 2B This is the third flowchart illustrating a method for determining rotational speed provided in this application embodiment;

[0015] Figure 2C This is the fourth flowchart illustrating a method for determining rotational speed provided in this application embodiment;

[0016] Figure 3 This is a schematic diagram of the structure of a speed determining device provided in an embodiment of this application;

[0017] Figure 4 This is one of the hardware structure diagrams of a medical device provided in the embodiments of this application;

[0018] Figure 5 This is the second schematic diagram of the hardware structure of a medical device provided in the embodiments of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0020] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] In traditional IMRT, the radiation incident direction is manually set by the planner and cannot be optimized. During treatment, the gantry rotates to a set position and remains stationary. Subfields of various shapes are formed by moving the MLC (Multiple Linear Array), and the same dose rate is used to deliver the dose. During gantry rotation, the radiation dose to each subfield differs. To ensure the expected radiation dose is achieved during gantry rotation, the maximum gantry speed is usually calculated based on the maximum radiation dose, and this speed is used to irradiate each subfield. However, this results in a longer irradiation time for the subfield corresponding to the minimum radiation dose, thus leading to a longer irradiation time of the radiotherapy equipment on the tumor target area.

[0022] This application optimizes the traditional IMRT (Intense Motion Therapy Unit) by first acquiring dose and blade data for all subfields corresponding to each gantry angle; then, based on this dose and blade data, determining the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution. This scheme optimizes the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution by using dose and blade data, resulting in a more uniform dose value for the subfields irradiated in each revolution. This allows subfields requiring longer irradiation times to be completed in the first few revolutions, thereby increasing the gantry rotation speed over multiple revolutions and ultimately reducing the overall operating time of the radiotherapy equipment.

[0023] The rotational speed determination method, apparatus, and device provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0024] like Figure 1As shown, this application provides a method for determining rotational speed. This method can be applied to medical devices used for radiotherapy, also known as radiotherapy equipment. The method includes steps S101 and S102.

[0025] S101. Obtain the dose data and leaf data of all subfields corresponding to each rack angle.

[0026] S102. Based on the dose data and the leaf data, determine the irradiation sequence of each subfield corresponding to each frame angle and the rotation speed of the frame per revolution.

[0027] The dose data for all subfields corresponding to each rack angle can be used to indicate the radiation dose, i.e., the dose value, in each subfield. The blade data for all subfields corresponding to each rack angle can be used to indicate the blade position of the MLC at each rack angle.

[0028] In this embodiment, the radiotherapy device includes a gantry and an MLC. The MLC includes multiple pairs of blades. During each rotation of the gantry (one rotation is 360°), the 360° is divided into multiple gantry angles, as shown in Table 1: 0°, 20°, 40°, ..., 340°. Each gantry angle corresponds to at least one beam, and each beam includes at least one segment.

[0029] It should be noted that, for a clearer understanding of the technical solution provided in this application, the following embodiments are all illustrated using the following example: each lap is divided into 18 gantry angles as shown in Table 1, with 5° of each gantry angle used for irradiation therapy (i.e., the gantry angle for moving from one subfield to the next), and 15° of each gantry angle used for MLC movement (i.e., the gantry angle for moving from one subfield MLC to the next). The maximum movement distance of the MLC is 4 cm / s. Each gantry angle includes 2 radiation fields, and each radiation field includes 3 subfields. The unit of radiation dose for each subfield is monitor unit (MU). This does not limit the embodiments of this application and can be determined according to actual usage requirements.

[0030] This application provides a method for determining rotation speed. First, dose data and blade data for all subfields corresponding to each gantry angle are acquired. Then, based on the dose data and blade data, the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed per revolution of the gantry are determined. This method optimizes the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed per revolution of the gantry by using dose data and blade data, resulting in a more uniform dose value for the subfields irradiated in each revolution of the gantry. This allows subfields requiring longer irradiation times to be completed in the first few revolutions, thereby increasing the gantry rotation speed over multiple revolutions and ultimately reducing the overall operating time of the radiotherapy equipment.

[0031] In one embodiment, the above-mentioned S102 can be implemented in the following two optional ways:

[0032] Option 1

[0033] S102 can be implemented by the following S102A to S102B.

[0034] S102A: Based on the blade data of all subfields corresponding to each frame angle, determine the irradiation sequence of each subfield in each frame angle and the rotation speed of the frame per revolution.

[0035] S102B: Based on the dose data of all subfields corresponding to each gantry angle, update the irradiation sequence of each subfield in each gantry angle and the rotation speed of the gantry per revolution.

[0036] The second optional implementation method

[0037] Combination Figure 1 ,like Figure 2A As shown, S102 can be implemented by the following S102C to S102D.

[0038] S102C. Based on the dose data of all subfields corresponding to each gantry angle, determine the irradiation sequence of each subfield in each gantry angle and the rotation speed of the gantry per revolution.

[0039] S102D updates the irradiation sequence of each subfield in each frame angle and the rotation speed of the frame per revolution based on the blade data of all subfields corresponding to each frame angle.

[0040] For the two optional implementation methods mentioned above, one approach is to first determine the irradiation sequence of subfields and the rotation speed of the gantry per revolution based on blade data, and then update the irradiation sequence of each subfield and the rotation speed of the gantry per revolution based on dose data. The other approach is to first determine the irradiation sequence of subfields and the rotation speed of the gantry per revolution based on dose data, and then update the irradiation sequence of each subfield and the rotation speed of the gantry per revolution based on blade data. Regardless of the method, both utilize dose data and blade data to optimize the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution.

[0041] To more clearly illustrate the rotation speed method provided in this application, the second optional implementation method described above will be used as an example for detailed explanation below.

[0042] For example, combined Figure 2A ,like Figure 2B As shown, S102C can be implemented by the following S102C1 to S102C3.

[0043] S102C1. Sort the dose data of all subfields corresponding to each gantry angle in descending order.

[0044] For example, the dose data mentioned above could be radiation dose values.

[0045] Table 1 is a table showing the correspondence between the gantry angle, firing field, subfield, and dose data of a plan provided in an embodiment of this application.

[0046] Table 1

[0047]

[0048] In Table 1, the 360° rotation is divided into 18 equal angles per revolution of the gantry. Taking gantry angle 0° as an example, angle 0° includes two radiation fields: Beam0 and Beam18. Beam0 includes Segment0, Segment1, and Segment2, and Beam18 includes Segment0, Segment1, and Segment2. Specifically, the radiation dose value for Segment0 corresponding to Beam0 is 5.36 MU, for Segment1 it is 5.89001 MU, and for Segment2 it is 4.85 MU. The radiation dose value for Segment0 corresponding to Beam18 is 11.4125 MU, for Segment1 it is 12.2434 MU, and for Segment2 it is 12.9441 MU.

[0049] After determining the correspondence between gantry angle, field of fire, subfield and dose data as shown in Table 1, each subfield can be numbered to obtain the correspondence table of gantry angle, field of fire, subfield and subfield number as shown in Table 2.

[0050] Table 2

[0051]

[0052] In Table 2, each number represents a subfield within a radiation field corresponding to a gantry angle. For example, B0S0 represents Segment 0 in Beam 0, with a radiation dose of 5.36 MU; B0S1 represents Segment 1 in Beam 0, with a radiation dose of 5.89001 MU; B0S2 represents Segment 2 in Beam 0, with a radiation dose of 4.85 MU; B18S0 represents Segment 0 in Beam 18, with a radiation dose of 11.4125 MU; B18S1 represents Segment 1 in Beam 18, with a radiation dose of 12.2434 MU; and B18S2 represents Segment 2 in Beam 18, with a radiation dose of 12.9441 MU.

[0053] For each gantry angle, all subfields corresponding to that gantry angle are sorted in descending order of dose value. For example, taking a gantry angle of 0° as an example, the six subfields corresponding to 0° are arranged in descending order of dose value (i.e., from highest to lowest): 12.9441 MU, 12.2434 MU, 11.4125 MU, 5.89001 MU, 5.36 MU, and 4.85 MU, with corresponding field numbers of B18S2, B18S1, B18S0, B0S1, B0S0, and B0S2. Thus, all subfields corresponding to each gantry angle can be sorted in descending order of dose value.

[0054] S102C2, The subfield ranked in the i-th position is determined as the subfield to be irradiated at the corresponding frame angle in the i-th rotation.

[0055] Where i takes values ​​of 1, 2...N in sequence.

[0056] N is the number of all subfields corresponding to each rack angle.

[0057] Table 3 shows the relationship between the subfields to be irradiated and each gantry angle in each rotation according to the embodiments of this application. As shown in Table 3, for a gantry angle of 0°, after arranging the 6 subfields corresponding to the gantry angle of 0° in descending order of dose value, the corresponding subfields are: B18S2, B18S1, B18S0, B0S1, B0S0, B0S2; for a gantry angle of 20°, after arranging the 6 subfields corresponding to the gantry angle of 20° in descending order of dose value, the corresponding subfields are: B19S2, B19S0, B19S1, B1S1, B1S0, B1S2... After arranging the 6 subfields corresponding to the gantry angle of 340° in descending order of dose value, the corresponding subfields are: B35S1, B35S2, B35S0, B17S1, B17S2, B17S0.

[0058] After sorting all subfields corresponding to each rack angle, the subfield B18S2, ranked first, corresponding to a rack angle of 0°, is determined as the subfield to be illuminated at a rack angle of 0° during the first rotation; the subfield B19S2, ranked first, corresponding to a rack angle of 20°, is determined as the subfield to be illuminated at a rack angle of 20° during the first rotation; and the subfield B20S0, ranked first, corresponding to a rack angle of 40°, is determined as the subfield to be illuminated at a rack angle of 40° during the first rotation. The subfields to be illuminated... and so on, the subfield B35S1 corresponding to the frame angle of 340°, ranked first, is determined as the subfield to be illuminated at the frame angle of 340° in the first rotation. Thus, the subfields to be illuminated from frame angle 0° to 340° in the first rotation can be determined as B18S2, B19S2, B20S0...B35S1, and further, the subfields to be illuminated from frame angle 0° to 340° in the i-th rotation can be determined. Here, i takes values ​​of 1, 2, 3, 4, 5, and 6, i.e., N = 6.

[0059] Table 3

[0060]

[0061]

[0062] S102C3. Based on the maximum dose data of all subfields in the i-th rotation, determine the rotation speed of the i-th rotation (hereinafter referred to as the target rotation speed).

[0063] Taking the division of 360° into 18 angles as an example, "the maximum dose data of all subfields in the i-th rotation" refers to the following: In the i-th rotation, the 18 subfields to be irradiated correspond to 18 dose values, and the maximum dose value among these 18 values ​​is taken as the maximum dose value among all subfields to be irradiated in the i-th rotation. For example, as shown in Table 3, in the first rotation, the dose value of subfield B32S2 is the maximum dose value among the 18 subfield dose values ​​corresponding to the first rotation.

[0064] According to Formula 1: Rotational speed in the i-th rotation = Angle used for irradiation therapy * Dose rate of the machine ÷ Maximum dose data of all subfields in the i-th rotation, the maximum rotational speed (i.e., the target rotational speed) in the i-th rotation can be calculated. Unit: degrees / second (° / s).

[0065] For example, assuming the machine's dose rate is 300 MU / min, meaning the machine can irradiate 5 MU per second, and the maximum dose in the first rotation is 20 MU, then according to the machine's dose rate, it would take 4 seconds to irradiate all 20 MU. Since 5° of the machine's movement from one subfield to the next is used for irradiation, the machine speed must at least satisfy the requirement of rotating 5° within 4 seconds. Therefore, the machine speed can be calculated to be 1.25° / s.

[0066] Thus, according to Table 3, after obtaining the maximum dose value among the dose values ​​of the subfield to be irradiated in each rotation, the target rotation speed for each rotation, as shown in Table 4, can be calculated according to Formula 1 above. It should be noted that since the preset maximum rotation speed of the gantry is 8° / s, when the rotation speed calculated according to Formula 1 exceeds 8° / s, the target rotation speed is still set to 8° / s.

[0067] Table 4

[0068] First lap Second lap Third lap Fourth lap Fifth lap Sixth lap Target speed 3.14° / S 3.99° / S 4.38° / S 6.97° / S 8° / S 8° / S

[0069] It is understandable that the target rotation speed is calculated based on the maximum dose value among all subfield dose values ​​in each rotation, thus satisfying the time required for 5° (the angle corresponding to the machine's movement from one subfield to the next) irradiation.

[0070] In this embodiment, by sorting all subfields corresponding to each gantry angle according to their dose data from largest to smallest, the dose values ​​of the subfields to be irradiated are more uniform in each rotation of the gantry, resulting in smaller differences in rotation speed calculated based on each dose data in each rotation. In the first few rotations, because the dose values ​​of each subfield are larger, the irradiation time is longer, and the gantry rotation speed is lower; in the later rotations, because the dose values ​​of each subfield are smaller, the irradiation time is shorter, and the gantry rotation speed is faster. Thus, the gantry rotation speed increases with each rotation, thereby reducing the overall operating time of the radiotherapy equipment.

[0071] For example, combined Figure 2A ,like Figure 2C As shown, when the blade data of all subfields corresponding to each rack angle are used to indicate the blade position of the MLC at each rack angle, the above S102D can be specifically implemented by the following S102D1 to S102D4.

[0072] S102D1. Based on the blade data of each subfield in the i-th rotation, calculate the MLC movement distance of the subfield corresponding to the angle of the adjacent frame in the i-th rotation.

[0073] It should be noted that the "MLC movement distance" mentioned above refers to the maximum required blade movement distance among multiple pairs of blades. Specifically, an MLC can include two sets of blades, with the two sets of blades arranged opposite each other. Taking a set of 40 blades as an example, by controlling the opening and closing of the 40 pairs of blades arranged opposite each other, the conformation of the target area can be achieved. In this case, the MLC movement distance refers to the maximum required blade movement distance among the 40 pairs of blades.

[0074] The IMRT provides blade data for each subfield in each rotation. Taking the i-th rotation as an example, since the blade data of each subfield in the i-th rotation can be used to indicate the position of a blade, the MLC movement distance of the subfield corresponding to the adjacent frame angle in the i-th rotation can be calculated based on the blade data of each subfield in the i-th rotation.

[0075] S102D2. Calculate the MLC movement time in the i-th rotation based on the MLC movement distance and MLC movement speed of the subfield corresponding to the angle of the adjacent frame in the i-th rotation.

[0076] For example, the MLC movement speed can be 4 cm / s as provided in S101 above.

[0077] After calculating the MLC movement distance of the subfield corresponding to any adjacent rack angle in the i-th rotation, the MLC movement time of the subfield corresponding to any adjacent rack angle in the i-th rotation can be calculated using Formula 2: MLC movement time = MLC movement distance ÷ MLC movement speed. After calculating the MLC movement time of the subfield corresponding to any adjacent rack angle, the largest MLC movement time can be selected as the MLC movement time in the i-th rotation.

[0078] S102D3. Calculate the frame movement time during the i-th rotation based on the rotational speed during the i-th rotation and the angle difference between adjacent frames.

[0079] S102D4. If the frame movement time in the i-th rotation is less than the MLC movement time in the i-th rotation, then based on the blade data of all subfields corresponding to each frame angle, update the irradiation order of each subfield in each frame angle and the rotation speed of the frame in each rotation.

[0080] Where i takes at least one value from 1, 2, ..., N.

[0081] Taking a frame angle of 15° as an example, the following relationship exists in each rotation: 15° ÷ first speed * MLC movement speed = maximum permissible distance between adjacent subfields. Based on the maximum permissible distance between adjacent subfields, it can be determined whether the frame can complete the MLC movement within the time of a 15° rotation. Specifically, if the maximum permissible distance between adjacent subfields is greater than or equal to the first movement distance (frame movement time is greater than or equal to MLC movement time), then the frame can complete the movement of the MLC from one subfield to the next within the time of a 15° rotation; if the maximum permissible distance between adjacent subfields is less than the first movement distance (i.e., frame movement time is less than MLC movement time), then the frame cannot complete the movement of the MLC from one subfield to the next within the time of a 15° rotation. Here, the first movement distance is the maximum distance between two adjacent subfields in each rotation.

[0082] In one scenario, if there is no excessive distance between MLCs in subfields during the first to sixth rotations, the rack can complete the movement of the MLC from one subfield to the next within a 15° rotation time. Thus, the target rotational speed corresponding to each rotation can be determined as the rack's rotational speed in each rotation. For example, as shown in Table 4, the rack's rotational speed is determined to be 3.14° / s in the first rotation, 3.99° / s in the second rotation, 4.38° / s in the third rotation, 6.97° / s in the fourth rotation, 8° / s in the fifth rotation, and 8° / s in the sixth rotation.

[0083] Another scenario is that in at least one of the rotations from the first to the sixth revolution, the distance between MLCs in subfields is too large. In this case, the rack cannot complete the MLC movement within the 15° rotation time. For example, assuming that the planning document determines that there is no excessive distance between MLCs in the first, second, and third revolutions, the rack can complete the movement of the MLC from one subfield to the next within the 15° rotation time. However, in the fourth, fifth, and sixth revolutions, there is an excessive distance between MLCs in the subfields, and the rack cannot complete the movement of the MLC from one subfield to the next within the 15° rotation time. Thus, the MLC movement is determined to be unsatisfactory.

[0084] For example, for cases where MLC motion is not satisfied, it is necessary to calculate the required motion distance for MLC in all subfields of each field and all subfields of the next field, and prioritize the two subfields with the largest MLC motion distance between each pair of subfields to be irradiated first. That is, update the irradiation order of each subfield in each rack angle and the rotation speed of the rack per revolution.

[0085] In one embodiment, the above-mentioned S102D4 can be implemented by (1) to (3).

[0086] (1) Based on the blade data of all subfields corresponding to each frame angle, determine the MLC movement distance between any two subfields in any two adjacent frame angles.

[0087] (2) Update the irradiation order of each subfield in each rack angle based on the MLC motion distance between any two subfields.

[0088] For example, based on the MLC motion distance between any two subfields, the illumination order of each subfield in each rack angle is updated, including: ranking the first subfield to the first position among all subfields corresponding to the first rack angle, and shifting the order of the other subfields corresponding to the first rack angle one position to the right. Ranking the second subfield to the first position among all subfields corresponding to the second rack angle, and shifting the order of the other subfields corresponding to the second rack angle one position to the right. The motion distance between the first and second subfields is the largest among all motion distances.

[0089] It should be noted that the "all movement distances" in the statement "the movement distance between the first subfield and the second subfield is the largest among all movement distances" includes the movement distances of any two subfields at any adjacent angle of any rack angle, and is not limited to the movement distances of all subfields corresponding to the first rack angle and all subfields corresponding to the second rack angle. This includes the distances required for MLC movement in all subfields corresponding to rack angle 0° and rack angle 20° in Table 5, the distances required for MLC movement in all subfields corresponding to rack angle 20° and rack angle 40° in Table 6, the distances required for MLC movement in all subfields corresponding to rack angle 40° and rack angle 60° in Table 7, and the movement distances of any two subfields at any other adjacent angle not shown.

[0090] The embodiments of this application include a process of reordering the irradiation sequence of subfields multiple times:

[0091] In the first reordering, if the MLC movement distance between the first subfield of the first rack angle and the second subfield of the second rack angle is the maximum distance among all MLC movement distances, then the first subfield is ordered to the first position among all subfields corresponding to the first rack angle, and the order of the other subfields corresponding to the first rack angle is shifted one position to the right; and the second subfield is ordered to the first position among all subfields corresponding to the second rack angle, and the order of the other subfields corresponding to the second rack angle is shifted one position to the right.

[0092] In the (j+1)th reordering, the reordering results of the subfields in the first j rounds are maintained. If the MLC movement distance between the third subfield at the third frame angle and the fourth subfield at the fourth frame angle is the maximum distance among all MLC movement distances of the other subfields except for the subfields to be irradiated in the first j rounds, then the third subfield is sorted to the (j+1)th position among the other subfields corresponding to the third frame angle, and the other subfields corresponding to the third frame angle are shifted one position to the right in turn; and the fourth subfield is sorted to the (j+1)th position among the other subfields corresponding to the fourth frame angle, and the other subfields corresponding to the fourth frame angle are shifted one position to the right in turn.

[0093] For example, Table 5 shows the distances required for MLC movement in all subfields corresponding to a rack angle of 0° and all subfields corresponding to a rack angle of 20°, as provided in the embodiments of this application. The distance 155 required for MLC movement between subfield B0S2 and subfield B19S2 is the maximum distance among all the distances required for MLC movement in all subfields corresponding to a rack angle of 0° and all the distances required for MLC movement in all subfields corresponding to a rack angle of 20°.

[0094] Table 5

[0095] B19S2 B19S0 B19S1 B1S1 B1S0 B1S2 B18S2 30 35 40 145 120 135 B18S1 55 55 55 145 120 140 B18S0 30 32 42 145 115 135 B0S1 142 132 142 50 65 60 B0S0 140 140 140 50 65 60 B0S2 155 152 155 57 60 57

[0096] Table 6 shows the distances required for MLC movement in all subfields at an angle of 20° and all subfields at an angle of 40°, as provided in the embodiments of this application. Among them, the distance 185 required for MLC movement between subfields B19S2 and B2S1 is the maximum distance among all the distances required for MLC movement in all subfields at an angle of 20° and all subfields at an angle of 40°.

[0097] Table 6

[0098] B20S0 B20S1 B20S2 B2S2 B2S0 B2S1 B19S2 70 30 30 120 130 185 B19S0 70 55 55 120 130 185 B19S1 70 37 30 120 125 185 B1S1 125 125 125 75 95 85 B1S0 125 125 125 75 75 85 B1S2 137 130 137 85 95 85

[0099] Table 7 shows the distances required for MLC movement in all subfields at an angle of 40° and all subfields at an angle of 60°, as provided in the embodiments of this application. The distance 150 required for MLC movement between subfields B2S1 and B21S1 is the maximum distance among all distances required for MLC movement in all subfields at an angle of 40° and all subfields at an angle of 60°.

[0100] Table 7

[0101]

[0102]

[0103] It should be noted that Tables 5 to 7 above are some examples provided in this application. The MLC movement distance at angles after 60° is not shown and can be determined according to actual usage requirements.

[0104] Assuming the MLC movement distance between subfields B19S2 and B2S1 is 185mm, which is the maximum distance among all MLC movement distances, then in the first reordering, subfield B19S2 can be ranked first among all subfields corresponding to a rack angle of 20°, and the other subfields corresponding to a rack angle of 20° can be shifted one position to the right; similarly, subfield B2S1 can be ranked first among all subfields corresponding to a rack angle of 40°, and the other subfields corresponding to a rack angle of 40° can be shifted one position to the right. The result of the first reordering is shown in Table 8.

[0105] Table 8

[0106] First lap Second lap Third lap Fourth lap Fifth lap Sixth lap angle B18S2 B18S1 B18S0 B0S1 B0S0 B0S2 0° B19S2 B19S0 B19S1 B1S1 B1S0 B1S2 20° B2S1 B20S0 B20S1 B20S2 B2S2 B2S0 40° B21S2 B21S1 B21S0 B3S2 B3S1 B3S0 60° B22S0 B4S2 B4S1 B4S0 B22S1 B22S2 80° B23S0 B5S2 B23S1 B5S0 B5S1 B23S2 100° B24S0 B24S1 B24S2 B6S2 B6S0 B6S1 120° B7S0 B25S0 B7S2 B7S1 B25S1 B25S2 140° B26S2 B26S1 B8S2 B26S0 B8S0 B8S1 160° B9S0 B27S2 B27S0 B9S2 B27S1 B9S2 180° B10S1 B10S0 B10S2 B28S1 B28S0 B28S2 200° B29S1 B11S1 B11S0 B11S2 B29S2 B29S0 220° B12S1 B12S2 B12S0 B30S0 B30S2 B30S1 240° B31S2 B31S1 B31S0 B13S1 B13S2 B13S0 260° B32S2 B32S0 B14S0 B14S2 B14S1 B32S1 280° B15S2 B33S1 B15S0 B33S0 B15S1 B33S2 300° B34S1 B34S0 B16S2 B16S0 B34S2 B16S1 320° B35S1 B35S2 B35S0 B17S1 B17S2 B17S0 340°

[0107] It should be noted that before the first reordering, since subfield B19S2 has already been ranked first among all subfields corresponding to rack angle 20°, all subfields corresponding to rack angle 20° can maintain their previous ranking in the first reordering without needing to be reordered. It is understood that if subfield B19S2 is not ranked first among all subfields corresponding to rack angle 20° before the first reordering, then it needs to be reordered in the first reordering. This can be determined according to actual usage requirements, and this application embodiment does not limit it.

[0108] In the second reordering, while maintaining the reordering results of the subfields to be irradiated in the first round as shown in Table 8, the MLC movement distance between any two subfields at adjacent angles corresponding to the second to sixth rounds is obtained, and all subfields in the second to sixth rounds are reordered according to the previous sorting method. Assuming that the MLC movement distance between subfield B34S2 at angle 320° and subfield B17S2 at angle 340° is the maximum distance among all MLC movement distances of all other subfields except those in the first round, subfield B34S2 is sorted to the second position among the other subfields corresponding to angle 320°, and the other subfields corresponding to angle 320° are shifted one position to the right; similarly, subfield B17S2 is sorted to the second position among the other subfields corresponding to angle 340°, and the other subfields corresponding to angle 340° are shifted one position to the right. This determines all the subfields to be irradiated in the second round.

[0109] Then, following the sorting method of the first and second circles, the subfields to be irradiated in the third circle, the fourth circle, the fifth circle, and the sixth circle are determined sequentially. It should be noted that after five re-sortings, since only the subfields of the sixth circle remain, there is no need to sort them. The final sorting results are shown in Table 9.

[0110] Table 9

[0111]

[0112]

[0113] (3) Based on the dose data and leaf data of each subfield after updating the irradiation sequence, update the rotation speed of the frame per revolution.

[0114] Specifically, it includes:

[0115] The first rotation speed is determined based on the maximum dose data of all subfields in the updated i-th rotation.

[0116] The second rotational speed is determined based on the maximum distance between the subfields corresponding to the angles of adjacent frames in the updated i-th rotation.

[0117] If the first rotational speed is greater than the second rotational speed, then the rotational speed of the i-th rotation of the frame is updated to the second rotational speed.

[0118] If the first rotational speed is less than or equal to the second rotational speed, then the rotational speed of the i-th rotation of the frame is updated to the first rotational speed.

[0119] For example, based on the sorting results in Table 9, there is a maximum distance in the MLC movement distance between two adjacent subfields to be irradiated in each rotation, so there are a total of 6 maximum distances.

[0120] MLC movement distance ÷ MLC movement speed = Time required for the MLC to move to the next subfield shape. Since 15° is reserved for MLC movement between every two subfields, to satisfy MLC movement, 15° ÷ Time required for MLC movement = Machine rotation speed. Thus, based on the maximum movement distance in the i-th rotation, the second speed corresponding to the i-th rotation can be determined.

[0121] Furthermore, based on the sorting results in Table 9, each of the 18 subfields to be irradiated in the i-th rotation corresponds to a dose data (dose value). Therefore, a maximum dose value can be determined from these 18 dose values, and the first rotation speed corresponding to the i-th rotation can be determined based on this maximum dose value.

[0122] Table 10 shows the correspondence between the first rotational speed and the second rotational speed provided in the embodiments of this application. Unit: m / s.

[0123] Table 10

[0124]

[0125]

[0126] Because the movement of the rack and MLC must be simultaneously satisfied, the smaller of the first and second rotational speeds is determined as the rack's rotational speed in the i-th rotation, as shown in Table 10. For example, in the first rotation, since the first rotational speed of 3.14 m / s is less than the second rotational speed of 3.24 m / s, the first rotational speed of 3.14 m / s is determined as the rack's rotational speed in the i-th rotation. Similarly, in the second rotation, since the first rotational speed of 4.08 m / s is greater than the second rotational speed of 3.64 m / s, the second rotational speed of 3.64 m / s is determined as the rack's rotational speed in the i-th rotation.

[0127] Based on the rotational speed of the frame in the i-th rotation determined in Table 10, the rotational time of the frame in the i-th rotation can be calculated using the formula: rotational time in the i-th rotation = 360° ÷ rotational speed of the frame in the i-th rotation.

[0128] As shown in Table 11, the time for the first rotation is 114.6 seconds, the time for the second rotation is 99 seconds, the time for the third rotation is 99 seconds, the time for the fourth rotation is 90 seconds, the time for the fifth rotation is 81 seconds, and the time for the sixth rotation is 66 seconds. The total time to complete the treatment is approximately 550 seconds.

[0129] Table 11

[0130] First lap Second lap Third lap Fourth lap Fifth lap Sixth lap Total Time Maximum speed 3.64 3.64 3.64 4 5.45 5.45 Time (seconds) 114.6 99 99 90 81 66 Approximately 550

[0131] In this embodiment, the irradiation sequence and rotation speed of the gantry can be further optimized based on the adjustable functions of the gantry speed and MLC movement speed, thereby reducing the overall working time of the radiotherapy equipment.

[0132] The speed determination device in this application embodiment can be a device, or it can be a component, integrated circuit, or chip in a terminal. The device can be a mobile electronic device or a non-mobile electronic device. For example, mobile electronic devices can be mobile phones, tablets, laptops, PDAs, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), etc., while non-mobile electronic devices can be servers, network attached storage (NAS), personal computers (PCs), etc. This application embodiment does not impose specific limitations.

[0133] The rotational speed determining device in this application embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit it.

[0134] The rotation speed determination device provided in this application embodiment can achieve... Figure 1 , Figures 2A to 2C The various processes implemented in the method implementation examples will not be described again here to avoid repetition.

[0135] like Figure 3 As shown in the figure, this application embodiment provides a speed determination device 300. The device includes an acquisition module 301 and a determination module 302.

[0136] The acquisition module 301 can be used to acquire dose data and blade data for all subfields corresponding to each gantry angle. The determination module 302 can be used to determine the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution based on the dose data and blade data acquired by the acquisition module 301.

[0137] In one embodiment, the determining module 302 can be specifically used to: determine the irradiation sequence of each subfield in each frame angle and the rotation speed of the frame per revolution based on the blade data of all subfields corresponding to each frame angle; and update the irradiation sequence of each subfield in each frame angle and the rotation speed of the frame per revolution based on the dose data of all subfields corresponding to each frame angle.

[0138] In one embodiment, the determining module 302 can be specifically used to: determine the irradiation sequence of each subfield in each gantry angle and the rotation speed of the gantry per revolution based on the dose data of all subfields corresponding to each gantry angle; and update the irradiation sequence of each subfield in each gantry angle and the rotation speed of the gantry per revolution based on the blade data of all subfields corresponding to each gantry angle.

[0139] In one embodiment, the determining module 302 is specifically used to: sort the dose data of all subfields corresponding to each gantry angle in descending order; determine the subfield ranked at position i as the subfield to be irradiated at the corresponding gantry angle in the i-th rotation; and determine the rotation speed of the i-th rotation based on the maximum dose data of all subfields in the i-th rotation. Here, i takes values ​​of 1, 2...N, and N is the number of all subfields corresponding to each gantry angle.

[0140] In one embodiment, the blade data of all subfields corresponding to each rack angle is used to indicate the blade position of the multi-leaf grating at each rack angle. The determining module 302 can specifically be used to: calculate the multi-leaf grating movement distance of the subfields corresponding to adjacent rack angles in the i-th rotation based on the blade data of each subfield in the i-th rotation; calculate the multi-leaf grating movement time in the i-th rotation based on the multi-leaf grating movement distance and the multi-leaf grating movement speed of the subfields corresponding to adjacent rack angles in the i-th rotation; calculate the rack movement time in the i-th rotation based on the rotational speed and the angular difference between adjacent rack angles; if the rack movement time in the i-th rotation is less than the multi-leaf grating movement time in the i-th rotation, then update the illumination order of each subfield in each rack angle and the rotational speed of the rack per rotation based on the blade data of all subfields corresponding to each rack angle. Here, i takes at least one value from 1, 2, ..., N.

[0141] In one embodiment, the determining module 302 can be specifically used to: determine the MLC movement distance between any two subfields in the multiple subfields corresponding to any two adjacent frame angles based on the blade data of all subfields corresponding to each frame angle; update the irradiation order of each subfield in each frame angle based on the MLC movement distance between the two subfields; and update the rotational speed of the frame per revolution based on the blade data of each subfield after updating the irradiation order.

[0142] In one embodiment, the determining module 302 is specifically used to: sort the first subfield to the first position among all subfields corresponding to the first rack angle, and shift the order of the other subfields corresponding to the first rack angle one position to the right; sort the second subfield to the first position among all subfields corresponding to the second rack angle, and shift the order of the other subfields corresponding to the second rack angle one position to the right. The MLC movement distance between the first subfield and the second subfield is the largest among all movement distances.

[0143] In one embodiment, the determining module 302 can be specifically used to: determine a first rotation speed based on the maximum dose data of all subfields in the updated i-th rotation; determine a second rotation speed based on the maximum distance among the movement distances between adjacent gantry angles corresponding to subfields in the updated i-th rotation; if the first rotation speed is greater than the second rotation speed, then update the rotation speed of the gantry rotation in the i-th rotation to the second rotation speed; if the first rotation speed is less than or equal to the second rotation speed, then update the rotation speed of the gantry rotation in the i-th rotation to the first rotation speed.

[0144] In this embodiment, the rotation speed determination device first acquires dose data and blade data for all subfields corresponding to each gantry angle; then, based on the dose data and blade data, it determines the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution. Through this scheme, because the dose data and blade data optimize the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution, the dose value of the subfields irradiated by the gantry in each revolution is more uniform. This allows subfields requiring longer irradiation times to be completed in the first few revolutions, thereby increasing the gantry rotation speed over multiple revolutions and ultimately reducing the overall working time.

[0145] Figure 4 This is a schematic diagram of the hardware structure of a medical device according to an embodiment of this application. The medical device includes a memory 41, a processor 42, a bus 43, and a communication interface 44; the memory 41 is used to store computer execution instructions, and the processor 42 is connected to the memory 41 via the bus 43; when the medical device is running, the processor 42 executes the computer execution instructions stored in the memory 41, so that the medical device performs the speed determination method provided in the above embodiment.

[0146] In the specific implementation, combined with Figure 4 ,like Figure 5 As shown, in one embodiment, processor 42 (42-1 and 42-2) may include one or more central processing units (CPUs), for example... Figure 5 CPU0 and CPU1 are shown in the diagram. As one embodiment, the medical device may include multiple processors 42, for example... Figure 5 The processors 42-1 and 42-2 are shown. Each of these processors 42 can be a single-core processor or a multi-core processor. Here, processor 42 can refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0147] The memory 41 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 41 may exist independently and be connected to the processor 42 via bus 43. The memory 41 may also be integrated with the processor 42.

[0148] In a specific implementation, memory 41 is used to store the data in this application and the computer execution instructions corresponding to the software program of this application. Processor 42 can perform various functions of the medical device by running or executing the software program stored in memory 41 and calling the data stored in memory 41.

[0149] Communication interface 44 uses any transceiver-like device for communicating with other devices or communication networks, such as control systems, radio access networks (RAN), wireless local area networks (WLAN), etc. Communication interface 44 may include a receiving unit to implement receiving functions and a transmitting unit to implement transmitting functions.

[0150] Bus 43 can be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. This bus 43 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0151] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described speed determination method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0152] The processor is the processor in the medical device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0153] This application also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described speed determination method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0154] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0155] It should be noted that, in this document, 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 limitations, 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 that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0156] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0157] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for determining rotational speed, characterized in that, The method includes: Acquire dose data and blade data for all subfields corresponding to each gantry angle. The dose data for all subfields corresponding to each gantry angle is used to indicate the radiation dose in each subfield, and the blade data for all subfields corresponding to each gantry angle is used to indicate the blade position of the multi-leaf grating at each gantry angle. Based on the dose data and the leaf data, the irradiation sequence of each subfield corresponding to each frame angle and the rotation speed of the frame per revolution are jointly determined. In this system, the irradiation sequence of each subfield corresponding to each frame angle is in descending order of the irradiation time of the subfield, and the rotation speed of the frame increases gradually with each revolution.

2. The method according to claim 1, characterized in that, The step of determining the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution based on the dose data and the leaf data includes: Based on the blade data of all subfields corresponding to each frame angle, determine the irradiation sequence of each subfield in each frame angle and the rotation speed of the frame per revolution; Based on the dose data of all subfields corresponding to each gantry angle, update the irradiation sequence of each subfield in each gantry angle and the rotation speed of the gantry per revolution.

3. The method according to claim 1, characterized in that, The step of determining the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution based on the dose data and the leaf data includes: Based on the dose data of all subfields corresponding to each gantry angle, determine the irradiation sequence of each subfield in each gantry angle and the rotation speed of the gantry per revolution; Based on the blade data of all subfields corresponding to each frame angle, update the irradiation order of each subfield in each frame angle and the rotation speed of the frame per revolution.

4. The method according to claim 3, characterized in that, The step of determining the irradiation sequence of each subfield and the rotation speed of the gantry per revolution based on the dose data of all subfields corresponding to each gantry angle includes: The dose data for all subfields corresponding to each gantry angle are sorted in descending order; The subfield ranked at position i is determined as the subfield to be irradiated at the corresponding frame angle in the i-th rotation. The rotation speed of the i-th rotation is determined based on the maximum dose data of all subfields in the i-th rotation. Where i takes values ​​of 1, 2...N, and N is the number of all subfields corresponding to each rack angle.

5. The method according to claim 4, characterized in that, The step of updating the irradiation order of each subfield and the rotational speed of the frame per revolution based on the blade data of all subfields corresponding to each frame angle includes: Based on the blade data of each subfield in the i-th rotation, calculate the multi-leaf grating movement distance of the subfield corresponding to the angle of the adjacent frame in the i-th rotation; Calculate the multileaf grating movement time in the i-th rotation based on the movement distance and speed of the multileaf grating in the subfield corresponding to the angle of the adjacent frame during the i-th rotation. Calculate the frame movement time in the i-th rotation based on the rotational speed during the i-th rotation and the angle difference between adjacent frames. If the frame movement time in the i-th rotation is less than the multi-leaf grating movement time in the i-th rotation, then based on the blade data of all subfields corresponding to each frame angle, update the illumination order of each subfield in each frame angle and the rotation speed of the frame in each rotation. Where i takes at least one value from 1, 2, ..., N.

6. The method according to claim 5, characterized in that, The step of updating the irradiation order of each subfield and the rotational speed of the frame per revolution based on the blade data of all subfields corresponding to each frame angle includes: Based on the blade data of all subfields corresponding to each frame angle, determine the multi-leaf grating movement distance between any two subfields in any two adjacent frame angles. Based on the multileaf grating movement distance between any two subfields, update the illumination order of each subfield in each rack angle; Based on the dose data and leaf data of each subfield after updating the irradiation sequence, the rotation speed of the frame per revolution is updated.

7. The method according to claim 6, characterized in that, The step of updating the illumination order of each subfield in each rack angle based on the multileaf grating movement distance between any two subfields includes: The first subfield is sorted to the first position among all subfields corresponding to the first frame angle, and the sorting of the other subfields corresponding to the first frame angle is shifted one position to the right in turn. The second subfield is sorted to the first position among all subfields corresponding to the second frame angle, and the sorting of the other subfields corresponding to the second frame angle is shifted one position to the right in turn; wherein, the multileaf grating movement distance between the first subfield and the second subfield is the largest among all multileaf grating movement distances.

8. The method according to claim 6, characterized in that, The step of updating the rotational speed of the gantry per revolution based on the dose data and leaf data of each subfield after updating the irradiation sequence includes: The first rotation speed is determined based on the maximum dose data of all subfields in the updated i-th rotation. The second rotation speed is determined based on the maximum distance in the multileaf grating movement distance between the adjacent frame angles corresponding to the subfields in the updated i-th rotation; If the first rotational speed is greater than the second rotational speed, then the rotational speed of the i-th rotation of the frame is updated to the second rotational speed; if the first rotational speed is less than or equal to the second rotational speed, then the rotational speed of the i-th rotation of the frame is updated to the first rotational speed.

9. A speed determining device, characterized in that, The device includes an acquisition module and a determination module; The acquisition module is used to acquire dose data and blade data of all subfields corresponding to each gantry angle. The dose data of all subfields corresponding to each gantry angle is used to indicate the radiation dose in each subfield, and the blade data of all subfields corresponding to each gantry angle is used to indicate the blade position of the multi-leaf grating at each gantry angle. The determining module is used to jointly determine the irradiation sequence of each subfield corresponding to each gantry angle and the rotation speed of the gantry per revolution based on the dose data and the leaf data obtained by the acquiring module. In this system, the irradiation sequence of each subfield corresponding to each frame angle is in descending order of the irradiation time of the subfield, and the rotation speed of the frame increases gradually with each revolution.

10. A medical device, characterized in that, It includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the speed determination method as described in any one of claims 1 to 8.

11. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the rotational speed determination method as described in any one of claims 1 to 8.

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