Method for measuring the accuracy of rotation of a rotating gantry

Abstract

This invention relates to a method for measuring the rotational accuracy of a rotating gantry, comprising: mounting a laser generator on a treatment head; mounting a calibration device on a treatment bed, the calibration device having a preset part; moving the treatment bed so that the preset part of the calibration device is located at the isocenter point of the rotating gantry; aligning the laser emitted by the laser generator on the treatment head with the preset part of the calibration device on the treatment bed; rotating the treatment head 180 degrees from its starting point and then back to its starting point, observing the positional relationship between the laser and the preset part during the rotation; and obtaining the rotational accuracy based on the positional relationship between the laser and the preset part. This method for measuring the rotational accuracy of a rotating gantry, through the positional relationship between the laser emitted by the laser generator and the preset part of the calibration device, can quickly measure the rotational accuracy of the rotating gantry, is simple to operate, and has a short measurement time.

Description

Technical Field

[0001] This invention relates to the field of proton radiotherapy, and more specifically to a method for measuring the rotational accuracy of a rotating gantry. Background Technology

[0002] Proton therapy for tumors is an internationally recognized cutting-edge radiotherapy technology, hailed as a "powerful tool for treating cancer" due to its excellent cancer-killing effect and relatively few side effects. A proton therapy device is used to perform proton beam therapy. It includes a proton accelerator, beam delivery system, beam distribution system, dose monitoring system, patient positioning system, and control system. The patient positioning system includes a treatment head, a rotating gantry, and a treatment bed. During treatment, the patient lies on the treatment bed, and the proton beam, after being amplified, enters the treatment head. The rotating gantry rotates the treatment head ±180 degrees, thus projecting the proton beam onto the patient's tumor area. To achieve the desired therapeutic effect, the proton beam needs to be accurately projected onto the tumor area; therefore, the rotational accuracy of the rotating gantry must be measured before treatment to ensure it meets preset requirements.

[0003] In existing technologies, a testing device is usually installed on the treatment head, with a target ball mounted on top of the testing device. The position of the target ball is tracked by a laser tracker. As the treatment head rotates from 0 to 180 degrees, the target ball data is measured at fixed angles. Multi-point data is obtained, fitted, and then the accuracy of its rotation center is calculated.

[0004] However, existing methods require the setup of a measuring device and a laser tracker for each measurement, and require specialized technicians to complete the task. The measurement time is too long and cannot meet the daily needs of hospitals. Summary of the Invention

[0005] The purpose of this invention is to provide a method for measuring the rotational accuracy of a rotating frame, so as to simply and quickly measure the rotational accuracy of the rotating frame.

[0006] To achieve the above objectives, the present invention provides a method for measuring the rotational accuracy of a rotating frame, comprising:

[0007] A laser generator is installed on the treatment head, and a calibration device is installed on the treatment bed. The calibration device has a preset part.

[0008] Move the treatment bed so that the preset part of the calibration device is located at the isocenter point of the rotating gantry;

[0009] Align the laser emitted by the laser generator on the treatment head with the preset part of the calibration device on the treatment bed;

[0010] The treatment head is rotated 180 degrees from the starting point and then returned to the starting point. During the rotation, the positional relationship between the laser and the preset part is observed.

[0011] The rotation accuracy is obtained based on the positional relationship between the laser and the preset part.

[0012] Furthermore, the laser generator is mounted on the treatment head via a rotary table, so that the laser generator is rotated by the rotary table, and the laser emitted by the laser generator is aligned with the preset part of the calibration device.

[0013] Furthermore, the calibration device includes a fixing member and a calibration ball, the calibration ball being fixed on the fixing member, and the calibration ball serving as a preset part of the calibration device.

[0014] Furthermore, the fixing member has a slot along the rotation direction, and the calibration ball is fixed in the slot.

[0015] Furthermore, the fastener is made of a transparent material.

[0016] Furthermore, the calibration ball is made of a non-transparent material.

[0017] Furthermore, the rotational accuracy is obtained based on the positional relationship between the laser and the preset part, specifically including:

[0018] If the laser is always on the calibration ball, then the rotational accuracy is determined to be less than the diameter of the calibration ball; if the laser is outside the calibration ball, then the rotational accuracy is determined to be greater than the diameter of the calibration ball.

[0019] Furthermore, the calibration device is a scale holder, on which a crosshair is provided along the rotation direction, serving as the preset part, and the laser emitted by the laser generator is aligned with the center of the crosshair at the starting point.

[0020] Furthermore, the scale holder is provided with X-axis positioning lines, Y-axis positioning lines and Z-axis positioning lines.

[0021] Furthermore, the rotational accuracy is obtained based on the positional relationship between the laser and the preset part, specifically including:

[0022] The distance deviation between the point on the scale frame illuminated by the laser and the center of the crosshair is obtained through the crosshair, and is used as the rotation accuracy.

[0023] The method for measuring the rotational accuracy of a rotating frame according to the present invention can quickly measure the rotational accuracy of a rotating frame by means of the laser emitted by a laser generator and the positional relationship between the preset part of the calibration device. The method is simple to operate and has a short measurement time. Attached Figure Description

[0024] Figure 1A flowchart of a method for measuring the rotational accuracy of a rotating frame according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of an apparatus for implementing the method of the present invention according to an embodiment of the present invention;

[0026] Figure 3 for Figure 2 A schematic diagram showing the connection relationship between the treatment head and the laser generator in the device;

[0027] Figure 4 for Figure 2 A schematic diagram of the calibration device in the instrument;

[0028] Figure 5 This is a schematic diagram of an apparatus for implementing the method of the present invention according to another embodiment;

[0029] Figure 6 for Figure 5 A schematic diagram of the scale holder of the device. Detailed Implementation

[0030] The preferred embodiments of the present invention are given below with reference to the accompanying drawings and described in detail.

[0031] like Figure 1 As shown, this embodiment of the invention provides a method for measuring the rotational accuracy of a rotating frame, comprising the following steps:

[0032] S100: A laser generator is installed on the treatment head, and a calibration device is installed on the treatment bed. The calibration device has a preset part.

[0033] S200: Move the treatment bed so that the preset part of the calibration device is located at the center point of the rotating frame;

[0034] S300: Aligns the laser emitted by the laser generator on the treatment head with the preset part of the calibration device on the treatment bed;

[0035] S400: Rotate the treatment head 180 degrees from the starting point and then back to the starting point. During the rotation, observe the positional relationship between the laser and the preset part.

[0036] S500: The rotational accuracy is obtained based on the positional relationship between the laser and the preset part.

[0037] like Figure 2As shown, the device for measuring rotational accuracy using the method of the present invention includes a laser generator 100 and a calibration device 200. The laser generator 100 is mounted on the treatment head 300, and the calibration device 200 is mounted on the treatment bed 400. During measurement, by moving the treatment bed 400, the preset part on the calibration device 200 can be positioned at the center point on the rotational axis of the rotating frame. Then, the position of the laser generator 100 on the treatment head 300 is adjusted so that the laser emitted by the laser generator 100 is aligned with the preset part of the calibration device 200. Then, the treatment head 300 is rotated 180 degrees and returned to the starting point. During the rotation, it is observed whether the laser is always at the preset part of the calibration device 200. If so, it can be determined that the rotational accuracy of the rotating frame is less than the range of the preset part; otherwise, the rotational accuracy of the rotating frame is greater than the range of the preset part. In this way, the user can make a basic judgment on the rotational accuracy of the rotating frame.

[0038] like Figure 3 As shown, in some embodiments, a rotating stage 110 may be provided on the treatment head 300, and a laser generator 100 is disposed on the rotating stage 110. The position of the laser generator 100 can be adjusted by the rotating stage 110, so that the emitted laser is aligned with the preset part of the calibration device 200. Both the laser generator 100 and the rotating stage 110 are existing devices, and their specific structures and principles will not be described in detail here.

[0039] In some embodiments, the laser generator 100 may have a rechargeable battery, thereby eliminating the need for wiring.

[0040] like Figure 4 As shown, in some embodiments, the calibration device 200 may include a fixing member 210 and a calibration ball 220, with the fixing member 210 aligned with the rotation direction of the treatment head 300. Figure 1 A slot 211 is provided in the direction of the middle arrow, and a calibration ball 220 is fixed in the slot 211. The calibration ball 220 serves as the preset part of the calibration device 200. During the rotation of the treatment head 300, the laser emitted by the laser generator 100 can always irradiate the slot 211.

[0041] The specific method for measuring spin accuracy using calibration ball 220 is as follows:

[0042] S11: Move the treatment bed 400 so that the calibration ball 220 is located at the isocenter of the rotating gantry.

[0043] The treatment room is typically equipped with a positioning laser light, which emits three orthogonal positioning laser beams. These three laser beams sweep across three orthogonal planes in space, and the projection of the laser beams onto an object is a straight line. The intersection of the projections of the three laser beams is the isocenter point, which also serves as the positioning reference for the treatment room. By moving the treatment bed 400, the movable fixing component 210 is moved so that the center of the calibration ball 220 is located at the isocenter point.

[0044] S12: Align the laser emitted by the laser generator 100 with the center of the calibration ball 220.

[0045] The position of the laser generator 100 is finely adjusted by the rotary table 110 so that the laser emitted by it is aligned with the center of the calibration ball 220.

[0046] S13: Rotate the treatment head 300 180 degrees and return it to the starting point. During the rotation, observe the positional relationship between the laser emitted by the laser generator 100 and the calibration ball 220.

[0047] The treatment head 300 is driven to rotate by the rotating frame. During measurement, the treatment head 300 can be rotated 180 degrees from the starting point (i.e., the 0-degree position, at which point the treatment head 300 is vertically downward) and then rotated back to the starting point from the 180-degree position.

[0048] S14: Determine the rotation accuracy of the rotating frame based on the positional relationship between the laser and the calibration ball 220.

[0049] If the laser beam is always illuminating the calibration sphere 220, it can be determined that the rotational accuracy is less than the diameter of the calibration sphere 220. If the laser beam is illuminating outside the calibration sphere 220, it can be determined that the rotational accuracy is greater than the diameter of the calibration sphere 220. In other words, the measuring device and method of this embodiment can only obtain a fuzzy range of rotational accuracy, not its precise value, and this range is related to the diameter of the calibration sphere 220. By changing the diameter of the calibration sphere 220, the measurement range of the rotational accuracy can be changed. The laser spot emitted by the laser generator 100 is adjustable to accommodate calibration spheres 220 of different diameters.

[0050] In some embodiments, the fixing member 210 can be a transparent material (e.g., a crystal block), and the calibration ball 220 can be a non-transparent material (e.g., stainless steel), thereby making it easier to observe the positional relationship between the laser and the calibration ball 220.

[0051] like Figure 5 As shown, in some other embodiments, the calibration device 200 can be a scale holder. For example... Figure 6As shown, a crosshair 230 is provided on the scale holder along the rotation direction. During rotation, the laser emitted by the laser generator 100 illuminates the scale holder. The distance deviation between the laser and the center of the crosshair 230 can be read through the crosshair 230, thus obtaining the rotation accuracy. The smallest division of the crosshair can be 1mm, which contains two-dimensional data (X-axis and Z-axis data). For example, if when the treatment head 300 rotates to 45 degrees, the X-axis deviation of the laser from the center of the crosshair is 2mm, and the Z-axis deviation is 1mm, then the rotation accuracy of the rotating frame at that angle is (2mm, 1mm). In some embodiments, it is not necessary to record the rotational accuracy of every angle; only a few key angles need to be recorded. Therefore, crosshair lines (i.e., 0-degree line, 45-degree line, 90-degree line, 135-degree line, and 180-degree line) can be set on the scale frame corresponding to the starting point of the treatment head 300 and the positions at 45 degrees, 90 degrees, 135 degrees, and 180 degrees, so that the rotational accuracy of the rotating frame at these angles can be obtained through the crosshair lines.

[0052] The method for measuring rotational accuracy using a scale frame includes the following steps:

[0053] S21: Move the treatment bed 400 or the scale frame so that the center of the crosshair 230 of the scale frame corresponding to the starting point of the treatment head 300 (i.e., the center position of the 0-degree line) is located at the isocenter point of the rotating frame.

[0054] Three positioning lines can be set on the scale frame, including X-axis positioning line 241, Y-axis positioning line 242 and Z-axis positioning line 243. By moving the treatment bed 400 or the scale frame, the projections of the three positioning lasers emitted by the positioning laser in the treatment room onto the scale frame can be made to coincide with the X-axis positioning line 241, Y-axis positioning line 242 and Z-axis positioning line 243 respectively, so that the center of the 0-degree line of the scale frame is located at the isocenter point.

[0055] S22: Align the laser emitted by the laser generator 100 with the center of the crosshair line 230 on the scale frame that corresponds to the starting point of the treatment head 300.

[0056] The position of the laser generator 100 is finely adjusted by the rotary table 110 so that the laser emitted by it is precisely aligned with the center of the crosshair line 230 of the scale frame corresponding to the starting point of the treatment head 300.

[0057] S23: Rotate the treatment head 300 180 degrees from the starting point and return it to the starting point. During the rotation, record the distance deviation between the laser and the center of the crosshair 230 at different angles of the treatment head 300, as the rotation accuracy at different angles.

[0058] The method for measuring the rotational accuracy of a rotating frame according to the present invention can quickly measure the rotational accuracy of the rotating frame by means of the positional relationship between the laser emitted by the laser generator 100 and the preset part of the calibration device 200. The method is simple to operate and has a short measurement time.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. That is, all simple and equivalent changes and modifications made based on the claims and description of this invention fall within the protection scope of the claims of this patent. All aspects not described in detail in this invention are conventional technical content.

Claims

1. A method for measuring the rotational accuracy of a rotating frame, characterized in that, Including the following steps: A laser generator is installed on the treatment head, and a calibration device is installed on the treatment bed. The calibration device has a preset part. Move the treatment bed so that the preset part of the calibration device is located at the isocenter point of the rotating gantry; Align the laser emitted by the laser generator on the treatment head with the preset part of the calibration device on the treatment bed; The treatment head is rotated 180 degrees from the starting point and then returned to the starting point. During the rotation, the positional relationship between the laser and the preset part is observed. The rotation accuracy is obtained based on the positional relationship between the laser and the preset part; The calibration device includes a fixing member and a calibration ball. The calibration ball is fixed to the fixing member and serves as a preset part of the calibration device. The rotational accuracy is obtained based on the positional relationship between the laser and the preset part, specifically including: if the laser is always on the calibration ball, the rotational accuracy is determined to be less than the diameter of the calibration ball; if the laser is outside the calibration ball, the rotational accuracy is determined to be greater than the diameter of the calibration ball. Alternatively, the calibration device is a scale frame with crosshairs along the rotational direction, serving as the preset part. The laser emitted by the laser generator is aligned with the center of the crosshairs at the starting point. The rotational accuracy is obtained based on the positional relationship between the laser and the preset part, specifically including: obtaining the distance deviation between the point on the scale frame illuminated by the laser and the center of the crosshairs through the crosshairs, as the rotational accuracy.

2. The method for measuring the rotational accuracy of a rotating frame according to claim 1, characterized in that, The laser generator is mounted on the treatment head via a rotary table, so that the laser generator is rotated by the rotary table to align the laser emitted by the laser generator with the preset part of the calibration device.

3. The method for measuring the rotational accuracy of a rotating frame according to claim 1, characterized in that, The fixing member has a slot along the rotation direction, and the calibration ball is fixed in the slot.

4. The method for measuring the rotational accuracy of a rotating frame according to claim 3, characterized in that, The fastener is made of a transparent material.

5. The method for measuring the rotational accuracy of a rotating frame according to claim 4, characterized in that, The calibration ball is made of a non-transparent material.

6. The method for measuring the rotational accuracy of a rotating frame according to claim 1, characterized in that, The scale holder is provided with X-axis positioning lines, Y-axis positioning lines and Z-axis positioning lines.

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