Method for positioning laser beam and calibrating treatment bed in radiotherapy

Abstract

The invention relates to a method for positioning a laser beam and calibrating a treatment bed in radiotherapy, which belongs to the technical field of radiotherapy and comprises the following steps: installing a laser reference module and an image sensing module; the laser reference module emits a reference laser beam, the machine head and the rack are rotated, the image sensing module receives a projection point of the reference laser beam and forms a track arc, the laser reference module is moved according to the deviation between the projection point of the reference laser beam and the geometric center of the track arc, and isocenter points of radiotherapy equipment are calibrated; moving the treatment bed; the positioning laser lamp module is installed and emits a positioning laser beam, the posture of the positioning laser lamp module is adjusted according to the deviation between the projection of the positioning laser beam received by the image sensing module and the isocenter point of the radiotherapy equipment, and calibration of the positioning laser beam and the treatment bed is completed. Professional technical experience is needed, a debugging result has subjectivity, and indexes cannot be specifically quantified.

Description

Technical Field

[0001] The invention belongs to the technical field of radiotherapy, and in particular relates to a method for calibrating a positioning laser beam and a treatment bed in radiotherapy. Background Art

[0002] In radiotherapy and radiodiagnosis, a laser lamp is generally used to emit a precise positioning laser beam. The doctor determines the patient's irradiation site by observing the reflection of the positioning laser beam on the patient's body, thereby ensuring that the irradiation is accurate.

[0003] During radiotherapy, a cross-line laser light is usually placed at the left and right ends of the radiotherapy device, and a straight-line laser light is placed at the top of the radiotherapy device. The three laser lights need to converge at the isocenter of the radiotherapy device, and the positioning laser beams emitted by the three laser lights should overlap with each other to form two orthogonal planes. The deviation of the overlapping positioning laser beams at each position must be ≤±0.5mm. During the entire course of radiotherapy, in order to improve the accuracy of each divided dose irradiation, it is necessary to ensure that the patient's position remains consistent during each treatment. Therefore, in clinical practice, a marker pen is generally used to draw a marking line on the patient's body surface at the location of the positioning laser irradiation during the patient's initial treatment. In subsequent treatments, the marking line is compared with the laser light irradiation line to ensure the consistency of the patient's position, thereby improving the accuracy of treatment.

[0004] In order to ensure that the positioning laser beam emitted by the laser lamp does not deviate beyond expectations, the position of the positioning laser beam needs to be regularly detected and adjusted. The existing detection and adjustment method is achieved by using the light field of the medical electron linear accelerator or the front pointer tooling. In essence, it is to find the accurate isocenter point in space through external indication or reference, so as to adjust the position of the laser lamp with the isocenter point as the reference benchmark. Specifically, the collimator rotation axis (beam center axis) and the rack rotation axis are found respectively through the front pointer tooling, and the coincidence point between the two axes is the isocenter point; the field light integrated in the accelerator head uses the projection of the black cross on the wall of the machine room as a reference benchmark to install and debug the laser lamp. Whether it is the light field debugging method or the front pointer tooling debugging method, the operator needs to have certain operating experience. At the same time, there are a lot of visual judgments in the debugging process, which makes the final debugging result subjective and unable to quantify specific indicators. Summary of the invention

[0005] In view of the various shortcomings of the existing technology, a method for calibrating the positioning laser beam and the treatment bed in radiotherapy is proposed to solve the technical problems in the existing technology that the laser lamp is manually debugged by visual inspection, professional technical experience is required, the debugging results are subjective, and specific quantitative indicators cannot be obtained.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for calibrating a positioning laser beam and a treatment bed in radiotherapy, comprising the following steps: S100, installing a laser reference module on the head and frame of the radiotherapy equipment respectively, and installing an image sensor module on the treatment bed; S200, the laser reference module emits a reference laser beam, and rotates the machine head and the frame respectively, the image sensor module records the projection point of the reference laser beam and forms a trajectory arc, and according to the deviation between the projection point of the reference laser beam and the geometric center of the trajectory arc, the laser reference module is moved to calibrate the center point of the radiotherapy equipment; S300, moving the treatment bed so that the geometric center of the image sensor module coincides with the center point of the radiotherapy equipment; S400, installing positioning laser light modules on the left side, right side and tail end of the treatment bed respectively, the positioning laser light module emits a positioning laser beam, and adjusts the posture of the positioning laser light module according to the deviation between the positioning laser beam projection recorded by the image sensor module and the center point of the radiotherapy equipment, so as to complete the calibration of the positioning laser beam and the treatment bed.

[0007] The present technical solution is further configured as follows: in step S100, a head laser reference module is installed on the head of the radiotherapy equipment, the head laser reference module can move along the X-axis and Y-axis of the three-dimensional coordinate system, and the head laser reference module emits a first reference laser beam along the Z-axis of the three-dimensional coordinate system, and a rack laser reference module is installed on the front end surface of the rack of the radiotherapy equipment, the rack laser reference module can move along the X-axis and Z-axis of the three-dimensional coordinate system, and the rack laser reference module emits a second reference laser beam along the Y-axis of the three-dimensional coordinate system.

[0008] The technical solution is further configured as follows: in step S100, the image sensing module includes an image analysis processor and an image sensor connected to each other, and a plurality of image sensors are provided to receive a reference laser beam and a positioning laser beam.

[0009] The technical solution is further configured as follows: in step S200, a geometric analysis is performed on the trajectory arc to calculate its geometric center, any point on the trajectory arc is taken as a reference laser beam projection point, and a deviation value between the reference laser beam projection point and the geometric center of the trajectory arc in the direction of the coordinate axis of the three-dimensional coordinate system is calculated, and the laser reference module is moved according to the deviation value, and the rotation and deviation value calculation are repeated until the trajectory arc is shrunk into a point, so as to calibrate the center point of the radiotherapy equipment.

[0010] The technical solution is further configured that the calibration of the isocenter of the radiotherapy device comprises the following steps: S201, rotating the machine head, calculating the deviation between the projection point of the first reference laser beam and the geometric center of its trajectory arc in the X-axis and Y-axis directions of the three-dimensional coordinate system, moving the machine head laser reference module according to the deviation value, repeating the rotation and deviation value measurement until the trajectory arc is shrunk into a point, so that the projection point of the first reference laser beam coincides with the center axis of the beam; S202, rotating the frame, calculating the deviation between the second reference laser beam projection point and the geometric center of its trajectory arc in the X-axis and Z-axis directions of the three-dimensional coordinate system, moving the frame laser reference module according to the deviation value, repeating the rotation and deviation value measurement until the trajectory arc is shrunk into a point, so that the second reference laser beam projection point coincides with the frame rotation axis; S203: The intersection point of the gantry rotation axis and the beam center axis is the isocenter of the radiotherapy equipment.

[0011] The present technical solution is further configured that, in step S400, the positioning laser light modules located on the left and right sides of the treatment bed can move along the Y axis and Z axis of the three-dimensional coordinate system, and can rotate around the X axis, Y axis and Z axis, and the positioning laser light module located at the rear end of the treatment bed can move along the X axis and Z axis of the three-dimensional coordinate system, and can rotate around the X axis, Y axis and Z axis.

[0012] The technical solution is further configured that the positioning laser light modules located on the left and right sides of the treatment bed use cross-line laser lights, and according to the deviation between the projection of the cross-line positioning laser lights received by the image sensor module and the center point of the radiotherapy equipment, the rotation amount of the cross-line laser lights around the X-axis, Y-axis, and Z-axis and the translation amount along the Y-axis and Z-axis are adjusted; The positioning laser light module located at the end of the treatment bed adopts a straight-line laser light. According to the deviation between the projection of the straight-line positioning laser beam received by the image sensor module and the center point of the radiotherapy equipment, the rotation amount of the straight-line laser light around the Y-axis and Z-axis and the translation amount along the X-axis are adjusted.

[0013] The technical solution is further configured that the rotation amount of the cross-line laser light around the X-axis, Y-axis, and Z-axis and the translation amount along the Y-axis and Z-axis are adjusted by: According to the deviation angle between the cross-line positioning laser light projection and the theoretical cross-line positioning laser light projection, the positioning laser light module is controlled to rotate around the X-axis, and the center of the theoretical cross-line positioning laser light projection coincides with the projection of the center point of the radiotherapy equipment until the cross-line positioning laser light projection is aligned; Control the treatment bed to move in a straight line in a direction perpendicular to the YZ plane. According to the offset of the cross-line positioning laser light projection before and after the movement, the deviation angles of the Y and Z axes are calculated through trigonometric calculations, and the positioning laser light module is controlled to rotate around the Y and Z axes respectively. According to the deviation values ​​between the cross-line positioning laser light projection and the theoretical cross-line positioning laser light projection in the Y-axis and Z-axis directions, the positioning laser light module is controlled to translate along the Y-axis and the Z-axis respectively until the cross-line positioning laser light projection coincides with the theoretical cross-line positioning laser light projection.

[0014] The technical solution is further configured as follows: the rotation amount of the linear laser light around the Y axis and the Z axis and the translation amount along the X axis are adjusted by: The treatment bed is controlled to move in a straight line in a direction perpendicular to the YZ plane. According to the offset of the one-line positioning laser beam projection before and after the movement, the deviation angles of the Y axis and the Z axis are obtained through trigonometric calculation, and the positioning laser light module is controlled to rotate around the Y axis and the Z axis respectively. The theoretical one-line positioning laser beam is projected through the center point of the radiotherapy equipment and is parallel to the Z axis. According to the deviation value between the one-line positioning laser beam projection and the theoretical one-line positioning laser beam projection in the X-axis direction, the positioning laser light module is controlled to translate along the X-axis until the one-line positioning laser beam projection coincides with the theoretical one-line positioning laser beam projection.

[0015] The technical solution is further configured to include step S500, removing the laser reference module and the image sensor module. The beneficial effects of the present invention are: By setting up the laser reference module and the image sensor module, the center point calibration of the radiotherapy equipment can be realized. By setting up the positioning laser light module and the image sensor module, the automatic calibration of the treatment bed and the positioning laser beam can be realized. It can be used for daily inspection of the radiotherapy equipment. Based on machine vision technology, it is simple to operate, does not require manual and visual debugging, does not rely on the operator's professional technical experience, and the results are quantifiable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of a method for calibrating a positioning laser beam and a treatment bed in radiotherapy in an embodiment of the present invention; Figure 2 is a side view of a treatment bed, a laser reference module, and an image sensor module in an embodiment of the present invention; Figure 3 is an axial view of a treatment bed, a laser reference module, and an image sensor module in an embodiment of the present invention; Figure 4 is a schematic diagram of an image sensing module in an embodiment of the present invention; Figure 5 is a disassembled view of an image sensor module in an embodiment of the present invention; Figure 6 is a schematic diagram of a third translation stage, an X-axis rotation assembly, a Y-axis rotation assembly, and a Z-axis rotation assembly in an embodiment of the present invention; Figure 7 is a schematic diagram of another perspective of the third translation stage, the X-axis rotation assembly, the Y-axis rotation assembly, and the Z-axis rotation assembly in the embodiment of the present invention; Figure 8 is a schematic diagram of a trajectory arc received by the image sensor in an embodiment of the present invention; Fig. 9 is a schematic diagram of a cross-line positioning laser light projection received by an image sensor in an embodiment of the present invention; Fig.10 yes Fig. 9 Schematic diagram after completing the X-axis rotation adjustment; Fig.11 Schematic diagram of the position change of the cross-line positioning laser light projection after the treatment bed moves linearly in an embodiment of the present invention; Fig.12 Schematic diagram of the position change of the treatment bed before and after the linear motion in the embodiment of the present invention; Fig.13 It is a schematic diagram of the linear offset after the rotation offset adjustment is completed; Fig.14 A schematic diagram of a point light source motion trajectory that is a non-circular trajectory in an embodiment of the present invention; Fig.15 Schematic diagram of the projection of the image sensor on the upper end surface of the mounting bracket in the YZ plane in an embodiment of the present invention.

[0017] In the attached drawings: 1. image sensor module; 11. mounting base; 12. mounting bracket; 13. image sensor; 14. filter; 2. head laser reference module; 3. rack laser reference module; 4. left positioning laser light module; 41. third translation stage; 42. X-axis rotation assembly; 421. first vertical plate; 422. worm of first worm gear assembly; 423. worm of first worm gear assembly; 424. first servo motor; 425. first bottom plate; 43. Y-axis rotation assembly; 431. first vertical plate; 432. worm of first worm gear assembly; 433. worm of first worm gear assembly; 434. first servo motor; 435. first bottom plate; 436. first servo motor; 437. first servo motor; 438. first servo motor; 439. first servo motor; 440. first servo motor; 441. first servo motor; 442. first servo motor; 443. first servo motor; 444. first servo motor; 445. first servo motor; 446. first servo motor; 447. first servo motor; 448. first servo motor; 449. first servo motor; 450. first servo motor; 451. first servo motor; 452. first servo motor; 453. first servo motor; 454. first servo motor; 455. first servo motor; 456. first servo motor; 457. first servo motor; 458. first servo motor; 459. first servo motor; 460. first servo motor; 461. first servo motor; 462. first servo motor; 463. first serv Second vertical plate; 432, the vortex of the second worm-turbine assembly; 433, the first fixed vertical plate; 434, the worm of the second worm-turbine assembly; 435, the second servo motor; 436, the second bottom plate; 44, the Z-axis rotation assembly; 441, the second fixed vertical plate; 442, the worm of the third worm-turbine assembly; 443, the third servo motor; 444, the turbine of the third worm-turbine assembly; 445, the third vertical plate; 446, the top plate; 45, the left-side positioning laser light; 5, the treatment bed; 6, the end-of-bed positioning laser light module. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional words used are used to illustrate rather than limit the invention.

[0019] According to an embodiment of the present invention, a method for calibrating a positioning laser beam and a treatment bed in radiotherapy is provided. Figure 1 , including the following steps: S100, installing a laser reference module on the head and frame of the radiotherapy equipment respectively, and installing an image sensor module on the treatment bed; S200, the laser reference module emits a reference laser beam, and rotates the machine head and the frame respectively, the image sensor module records the projection point of the reference laser beam and forms a trajectory arc, and according to the deviation between the projection point of the reference laser beam and the geometric center of the trajectory arc, the laser reference module is moved to calibrate the center point of the radiotherapy equipment; S300, moving the treatment bed so that the geometric center of the image sensor module coincides with the center point of the radiotherapy equipment; S400, installing positioning laser light modules on the left side, right side and tail end of the treatment bed respectively, the positioning laser light module emits a positioning laser beam, and adjusts the posture of the positioning laser light module according to the deviation between the positioning laser beam projection recorded by the image sensor module and the center point of the radiotherapy equipment, so as to complete the calibration of the positioning laser beam and the treatment bed.

[0020] It should be noted that by setting up a laser reference module and an image sensor module, the calibration of the center point of radiotherapy equipment and the like can be achieved, and by setting up a positioning laser light module and an image sensor module, automatic calibration of the treatment bed and the positioning laser beam can be achieved, which can be used for daily inspection of radiotherapy equipment. Based on machine vision technology, the operation is simple, no manual or visual debugging is required, it does not rely on the operator's professional technical experience, and the results are quantifiable.

[0021] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figures 1 to 3In step S100, a head laser reference module 2 is installed on the head of the radiotherapy equipment, and the head laser reference module 2 can move along the X-axis and the Y-axis of the three-dimensional coordinate system, and the head laser reference module 2 emits a first reference laser beam along the Z-axis of the three-dimensional coordinate system. A rack laser reference module 3 is installed on the front end surface of the rack of the radiotherapy equipment, and the rack laser reference module 3 can move along the X-axis and the Z-axis of the three-dimensional coordinate system, and the rack laser reference module 3 emits a second reference laser beam along the Y-axis of the three-dimensional coordinate system. The first reference laser beam and the second reference laser beam are both pencil laser beams.

[0022] Specifically, the head laser reference module 2 includes a first translation stage and a first reference laser light, and the first reference laser light is arranged on the first translation stage. Similarly, the frame laser reference module 3 includes a second translation stage and a second reference laser light, and the second reference laser light is arranged on the second translation stage. It should be noted that the first translation stage and the second translation stage are both common two-dimensional electric translation stages on the market, which are mature existing technologies and will not be described in detail here.

[0023] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figures 1 to 5 In step S100, the image sensing module 1 includes an image analysis processor and an image sensor 13 connected to each other. A plurality of image sensors 13 are provided to receive a reference laser beam and a positioning laser beam.

[0024] Specifically, the image sensor module 1 also includes a mounting bracket 12, the image analysis processor is arranged inside the mounting bracket 12, the image analysis processor integrates software for analyzing and calculating the received laser beam, and the image sensor 13 is arranged on the side of the mounting bracket 12. The image sensor module 1 is installed at the front end of the treatment bed 5 close to the frame of the radiotherapy equipment, and a mounting base 11 is arranged below the mounting bracket 12, and the mounting base 11 is used to adapt to the panel of the treatment bed 5 for connection and fixation. At the same time, the image analysis processor is respectively connected to the treatment bed 5, the head laser reference module 2, the frame laser reference module 3 and the positioning laser light module, and can adjust the posture and position of the treatment bed 5, the first reference laser light, the second reference laser light and the positioning laser according to the result of the analysis of the received signal, so as to realize the automatic control of the whole device without manual operation. Correspondingly, image sensors 13 for receiving laser beam projection are installed at the front, rear, upper, left and right end faces of the mounting bracket 12, and preferably, the image sensor 13 is a CMOS sensor. Figure 4 , Figure 5 The rear end face is not shown, and is arranged in a mirror image with the front end face.

[0025] It should be noted that the image sensor 13 in the image sensor module 1 reads the projection position of the laser beam thereon. The image sensor 13 is distributed in pixels, and the projection position of the laser beam can be positioned at the micron level to ensure the accuracy of the calibration result. In addition, a filter 14 is provided on the surface of the image sensor 13 and away from the mounting bracket 12 to filter the laser beam, thereby filtering non-measurement light and improving measurement accuracy.

[0026] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figure 1 as well as Figure 8 In step S200, the trajectory arc is geometrically analyzed to calculate its geometric center, any point on the trajectory arc is taken as the reference laser beam projection point, the deviation value between the reference laser beam projection point in the projection plane and the geometric center of the trajectory arc in each coordinate axis direction is calculated, the laser reference module is moved according to the deviation value, and the rotation and deviation value measurement are repeated until the trajectory arc is shrunk into a point, and the center point of the radiotherapy equipment is calibrated. Taking the laser reference module 2 of the handpiece as an example, see Figure 8 , take any point on the projection trajectory arc of the module on the image sensor module 1, calculate the deviation value between the point and the geometric center of the trajectory arc in the X-axis and Y-axis directions, move the head laser reference module 2 according to the deviation value, repeat the head rotation and deviation value measurement until the trajectory arc shrinks into a point; similarly, adjust the rack laser reference module 3 until the projection trajectory arc of the second reference laser light in the rack laser reference module 3 shrinks into a point, thereby realizing the calibration of the center point of the radiotherapy equipment.

[0027] It should be noted that the first reference laser light and the second reference laser light both use point light sources, and the laser beams (first reference laser beam and second reference laser beam) emitted by the point light sources are projected onto the image sensor module 1, and the image sensor 13 reads the projection point of the point light source. As the head and the frame rotate, the image sensor 13 reads the arc of the point light source trajectory.

[0028] Specifically, the calibration of the isocenter of the radiotherapy equipment includes the following steps: S201, rotate the machine head, calculate the deviation between the first reference laser beam projection point and the geometric center of its trajectory arc in the X-axis and Y-axis directions of the three-dimensional coordinate system, move the machine head laser reference module 2 according to the deviation value, repeat the rotation and deviation value measurement until the trajectory arc is contracted into a point, so that the first reference laser beam projection point coincides with the beam centerline.

[0029] It should be noted that the machine head performs self-rotation motion, and the machine head rotates along the beam center axis with the machine head laser reference module 2. The image sensor 13 on the upper end surface of the mounting bracket 12 will record the motion trajectory of the first reference laser beam projection point (the trajectory arc of the first reference laser beam projection point along the beam center axis) during this process, perform geometric analysis on the trajectory arc to calculate the geometric center, calculate the deviation value between the first reference laser beam projection point and the beam center axis in the X-axis and Y-axis directions, and control the first translation stage to move. After completing the adjustment of the first translation stage, the machine head can be repeatedly rotated to measure the deviation to achieve the coincidence of the first reference laser beam projection point with the beam center axis.

[0030] S202, rotating the frame, calculating the deviation between the second reference laser beam projection point and the geometric center of its trajectory arc in the X-axis and Z-axis directions of the three-dimensional coordinate system, moving the frame laser reference module according to the deviation value, repeating the rotation and deviation value measurement until the trajectory arc is contracted into a point, so that the second reference laser beam projection point coincides with the frame rotation axis.

[0031] It should be noted that the image sensor 13 on the front end surface of the mounting bracket 12 records the motion trajectory of the projection point of the second reference laser beam, calculates the deviation value, and controls the second translation stage to move.

[0032] S203: The intersection point of the gantry rotation axis and the beam center axis is the isocenter of the radiotherapy equipment.

[0033] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figure 1 In step S300, after the calibration of the isocenter of the radiotherapy equipment is completed, the treatment bed 5 is controlled to move by reading the difference between the coordinates of the isocenter of the radiotherapy equipment and the coordinates of the geometric center of the image sensor module 1, and the geometric center of the image sensor module 1 is moved to the isocenter, so that the geometric center of the image sensor module 1 coincides with the isocenter, and then the geometric center of the image sensor module 1 is used as the calibration reference for positioning the laser light module.

[0034] It should be noted that during the use of the treatment bed 5, due to factors such as wear of components or foundation sinking, the motion coordinate system of the treatment bed may deviate from the coordinate system of the radiotherapy equipment. This deviation includes angular deviation and linear deviation. Therefore, when calibrating the treatment bed 5, it is necessary to complete the measurement and adjustment of these two parts of the offset separately.

[0035] Since the treatment bed 5 may have a certain inclination angle, that is, the motion coordinate system of the treatment bed 5 is inclined with the coordinate system of the radiotherapy device, the motion trajectory of the point light source may not be a perfect circular trajectory. Fig.14, the motion trajectory of the point light source may be an arc. When the image sensor module 1 is calibrated at the center point, it can measure and record the size of the long side A and the short side B. The trigonometric function calculation of the movement stroke of the translation stage and the stroke received by the image sensor can be used to obtain the angle deviation of the treatment bed 5. Please refer to Fig.15 , which is a projection of the image sensor on the upper end of the mounting bracket 12 in the YZ plane, wherein the stroke received by the image sensor is Fig.14 The image sensor on the front end of the mounting bracket 12 can receive deviations in the X-axis and Z-axis directions, and the image sensor on the upper end of the mounting bracket 12 can receive deviations in the X-axis and Y-axis directions.

[0036] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figures 2 to 7 In step S400, the positioning laser light modules located on the left and right sides of the treatment bed 5 serve as the left positioning laser light module 4 and the right positioning laser light module respectively, and both of them can move along the Y axis and Z axis of the three-dimensional coordinate system, and can rotate around the X axis, Y axis and Z axis; the positioning laser light module located at the tail end of the treatment bed 5 serves as the bed end positioning laser light module 6, and the bed end positioning laser light module 6 can move along the X axis and Z axis of the three-dimensional coordinate system, and can rotate around the X axis, Y axis and Z axis.

[0037] The structures of the left-side positioning laser light module 4, the right-side positioning laser light module and the end-of-bed positioning laser light module 6 are the same, and the only difference is the installation direction. Taking the left-side positioning laser light module 4 as an example, the left-side positioning laser light module includes a left-side positioning laser light 45 and a third displacement stage 41, and the third displacement stage 41 can move along the Y-axis and Z-axis of the three-dimensional coordinate system. The third displacement stage 41 is also provided with an X-axis rotation component 42, a Y-axis rotation component 43 and a Z-axis rotation component 44.

[0038] Specifically, the X-axis rotation assembly 42 includes a first bottom plate 425 and a first worm gear assembly. The first bottom plate 425 is connected to the third translation stage 41. The rotation axis of the worm gear 423 of the first worm gear assembly is arranged along the X-axis direction of the three-dimensional coordinate system. The worm gear 422 of the first worm gear assembly is fixed above the first bottom plate 425 by the first vertical plate 421. The worm gear 422 of the first worm gear assembly is meshed with the worm gear 423 of the first worm gear assembly. The worm gear 422 of the first worm gear assembly is controlled to rotate by the first servo motor 424, thereby realizing the rotation of the worm gear 423 of the first worm gear assembly around the X-axis, so as to achieve the purpose of rotating the left positioning laser light 45 around the X-axis direction.

[0039] Specifically, the Y-axis rotation assembly 43 includes a second bottom plate 436 and a second worm gear assembly. The rotation axis of the worm gear 432 of the second worm gear assembly is hinged to the second bottom plate 436, and the rotation axis of the worm gear 432 of the second worm gear assembly is arranged along the Y-axis of the three-dimensional coordinate system. The second bottom plate 436 is connected to the rotation axis of the worm gear 432 of the second worm gear assembly through the second vertical plate 431. The lower end of the worm gear 432 of the second worm gear assembly is meshed with the worm gear 434 of the second worm gear assembly. The worm gear 434 of the second worm gear assembly is fixed to the second bottom plate 436 through the first fixed vertical plates 433 at both ends. The other end of the worm gear 434 of the second worm gear assembly is connected to the second servo motor 435 for rotation control, so that it can rotate along the Y-axis.

[0040] Specifically, the Z-axis rotation assembly 44 includes a top plate 446 and a third worm gear assembly. The third worm gear assembly and the second worm gear assembly are respectively located on adjacent sides of the second bottom plate 436. The rotating shaft of the worm gear of the third worm gear assembly is arranged along the Z axis of the three-dimensional coordinate system, and the rotating shaft of the worm gear of the third worm gear assembly is hinged to the top plate 446. The left positioning laser light 45 is arranged on the top plate 446. The top of the second bottom plate 436 is connected to the rotating shaft of the worm gear of the third worm gear assembly through the third vertical plate 445. The lower end of the worm gear 444 of the third worm gear assembly is meshed with the worm gear 442 of the third worm gear assembly. The worm gear 442 of the third worm gear assembly is fixed to the second bottom plate 436 through the second fixed vertical plates 441 at both ends. The other end of the worm gear 442 of the third worm gear assembly is connected to the third servo motor 443 for rotation control, so that it can rotate along the Z axis.

[0041] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figures 2 to 7 The positioning laser light modules located on the left and right sides of the treatment bed use cross-line laser lights. According to the deviation between the projection of the cross-line positioning laser lights received by the image sensor module 1 and the center point of the radiotherapy equipment, the rotation amount of the cross-line laser lights around the X-axis, Y-axis, and Z-axis and the translation amount along the Y-axis and Z-axis are adjusted; The positioning laser light module located at the end of the treatment bed adopts a straight line laser light. According to the deviation between the straight line positioning laser beam projection received by the image sensor module 1 and the center point of the radiotherapy equipment, the rotation amount of the straight line laser light around the Y axis and Z axis and the translation amount along the X axis are adjusted.

[0042] Taking the left positioning laser light module 4 as an example, the left positioning laser light module 4 emits a cross-line positioning laser light projected on the image sensor module 1, and the image sensor 13 on the left end face of the mounting bracket 12 receives the cross-line positioning laser light projection, see Fig. 9According to the deviation angle between the cross-line positioning laser light projection and the theoretical cross-line positioning laser light projection, the center of the theoretical cross-line positioning laser light projection coincides with the projection of the center point of the radiotherapy equipment, and the X-axis rotation component 42 is controlled to complete the tilt deviation adjustment of the image around the X-axis until the image sensor 13 detects that the cross-line is aligned, see Fig.10 After the X-axis rotation deviation adjustment is completed, the Y-axis and Z-axis rotation deviations need to be adjusted. The principle of detecting the Y-axis and Z-axis rotation deviations is: by controlling the treatment bed 5 to move in a straight line in a direction perpendicular to the YZ plane (along the X-axis direction), the image sensor 13 is used to monitor the crosshairs during the entire stroke. If the crosshairs are offset before and after the movement, there is a deviation. Please refer to Fig.11 , detect the offset and perform trigonometric calculations to obtain the deviation angles of the Y and Z axes. Fig.12 , control the Y-axis rotation component 43 and the Z-axis rotation component 44 to rotate, and the adjustment can be completed. After the rotation amount is adjusted, adjust the linear offset, refer to Fig.13 The image sensor 13 directly reads the offset of the cross-line positioning laser light projection and the theoretical cross-line positioning laser light projection in the Y-axis and Z-axis directions, and controls the third translation stage 41 to translate along the Y-axis and the Z-axis until the cross-line positioning laser light projection coincides with the theoretical cross-line positioning laser light projection, thereby completing the calibration of the left-side positioning laser light module 4 and the right-side positioning laser light module.

[0043] When calibrating the bed end positioning laser light module 6, the bed end positioning laser light is a straight line laser light, so it has only three degrees of freedom deviation in space, namely, the inclination deviation around the Y axis, the inclination deviation around the Z axis, and the straight line deviation along the X axis. The calibration process is the same as the above process and will not be repeated.

[0044] In the method for locating the laser beam and the treatment bed in the radiotherapy of this embodiment, please refer to Figures 2 to 3 , further comprising step S500, removing the laser reference module and the image sensor module 1, specifically, removing the head laser reference module 2, the frame laser reference module 3 and the image sensor module 1.

[0045] That is to say, before calibration, the operator only needs to install the head laser reference module 2 on the head, install the rack laser reference module 3 on the front face of the rack, and install the image sensor module 1 at the front end of the carbon fiber bed surface of the treatment bed, and all manual operations in the prior art can be completed, and the calibration process is completed by the automated program. After the calibration is completed, the operator removes and stores the installed head laser reference module 2, rack laser reference module 3, and image sensor module 1.

[0046] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made within the scope of this application should still fall within the scope of the present invention.

Claims

1. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy, characterized in that: The following steps are involved: S100, installing a laser reference module on the head and frame of the radiotherapy equipment respectively, and installing an image sensor module on the treatment bed; S200, the laser reference module emits a reference laser beam, and rotates the machine head and the frame respectively, the image sensor module records the projection point of the reference laser beam and forms a trajectory arc, and according to the deviation between the projection point of the reference laser beam and the geometric center of the trajectory arc, the laser reference module is moved to calibrate the center point of the radiotherapy equipment; S300, moving the treatment bed so that the geometric center of the image sensor module coincides with the center point of the radiotherapy equipment; S400, installing positioning laser light modules on the left side, right side and tail end of the treatment bed respectively, the positioning laser light module emits a positioning laser beam, and adjusts the posture of the positioning laser light module according to the deviation between the positioning laser beam projection recorded by the image sensor module and the center point of the radiotherapy equipment, so as to complete the calibration of the positioning laser beam and the treatment bed.

2. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 1, characterized in that: In step S100, a handpiece laser reference module is installed on the handpiece of the radiotherapy equipment, the handpiece laser reference module can move along the X-axis and the Y-axis of the three-dimensional coordinate system, and the handpiece laser reference module emits a first reference laser beam along the Z-axis of the three-dimensional coordinate system, and a rack laser reference module is installed on the front end surface of the rack of the radiotherapy equipment, the rack laser reference module can move along the X-axis and the Z-axis of the three-dimensional coordinate system, and the rack laser reference module emits a second reference laser beam along the Y-axis of the three-dimensional coordinate system.

3. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 1, characterized in that: In step S100, the image sensing module includes an image analysis processor and an image sensor connected to each other, and a plurality of image sensors are provided to receive a reference laser beam and a positioning laser beam.

4. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 2, characterized in that: In step S200, a geometric analysis is performed on the trajectory arc to calculate its geometric center, and any point on the trajectory arc is taken as a reference laser beam projection point. The deviation value between the reference laser beam projection point and the geometric center of the trajectory arc in the direction of the coordinate axis of the three-dimensional coordinate system is calculated, and the laser reference module is moved according to the deviation value. The rotation and deviation value calculation are repeated until the trajectory arc is shrunk into a point, and the center point of the radiotherapy equipment is calibrated.

5. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 4, characterized in that: The method of calibrating the isocenter of the radiotherapy equipment comprises the following steps: S201, rotating the machine head, calculating the deviation between the projection point of the first reference laser beam and the geometric center of its trajectory arc in the X-axis and Y-axis directions of the three-dimensional coordinate system, moving the machine head laser reference module according to the deviation value, repeating the rotation and deviation value measurement until the trajectory arc is shrunk into a point, so that the projection point of the first reference laser beam coincides with the center axis of the beam; S202, rotating the frame, calculating the deviation between the second reference laser beam projection point and the geometric center of its trajectory arc in the X-axis and Z-axis directions of the three-dimensional coordinate system, moving the frame laser reference module according to the deviation value, repeating the rotation and deviation value measurement until the trajectory arc is shrunk into a point, so that the second reference laser beam projection point coincides with the frame rotation axis; S203: The intersection point of the gantry rotation axis and the beam center axis is the isocenter of the radiotherapy equipment.

6. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 1, characterized in that: In step S400, the positioning laser light modules located on the left and right sides of the treatment bed can move along the Y axis and Z axis of the three-dimensional coordinate system, and can rotate around the X axis, Y axis and Z axis. The positioning laser light module located at the rear end of the treatment bed can move along the X axis and Z axis of the three-dimensional coordinate system, and can rotate around the X axis, Y axis and Z axis.

7. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 6, characterized in that: The positioning laser light modules located on the left and right sides of the treatment bed use cross-line laser lights. According to the deviation between the projection of the cross-line positioning laser lights received by the image sensor module and the center point of the radiotherapy equipment, the rotation amount of the cross-line laser lights around the X-axis, Y-axis, and Z-axis and the translation amount along the Y-axis and Z-axis are adjusted; The positioning laser light module located at the end of the treatment bed adopts a straight-line laser light. According to the deviation between the projection of the straight-line positioning laser beam received by the image sensor module and the center point of the radiotherapy equipment, the rotation amount of the straight-line laser light around the Y-axis and Z-axis and the translation amount along the X-axis are adjusted.

8. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 7, characterized in that: The specific method for adjusting the rotation amount of the cross-line laser light around the X-axis, Y-axis, and Z-axis and the translation amount along the Y-axis and Z-axis is as follows: According to the deviation angle between the cross-line positioning laser light projection and the theoretical cross-line positioning laser light projection, the positioning laser light module is controlled to rotate around the X-axis, and the center of the theoretical cross-line positioning laser light projection coincides with the projection of the center point of the radiotherapy equipment until the cross-line positioning laser light projection is aligned; Control the treatment bed to move in a straight line in a direction perpendicular to the YZ plane. According to the offset of the cross-line positioning laser light projection before and after the movement, the deviation angles of the Y and Z axes are calculated through trigonometric calculations, and the positioning laser light module is controlled to rotate around the Y and Z axes respectively. According to the deviation values ​​between the cross-line positioning laser light projection and the theoretical cross-line positioning laser light projection in the Y-axis and Z-axis directions, the positioning laser light module is controlled to translate along the Y-axis and the Z-axis respectively until the cross-line positioning laser light projection coincides with the theoretical cross-line positioning laser light projection.

9. A method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 7, characterized in that: The specific method for adjusting the rotation amount of the line laser light around the Y axis and Z axis and the translation amount along the X axis is as follows: The treatment bed is controlled to move in a straight line in a direction perpendicular to the YZ plane. According to the offset of the one-line positioning laser beam projection before and after the movement, the deviation angles of the Y axis and the Z axis are obtained through trigonometric calculation, and the positioning laser light module is controlled to rotate around the Y axis and the Z axis respectively. The theoretical one-line positioning laser beam is projected through the center point of the radiotherapy equipment and is parallel to the Z axis. According to the deviation value between the one-line positioning laser beam projection and the theoretical one-line positioning laser beam projection in the X-axis direction, the positioning laser light module is controlled to translate along the X-axis until the one-line positioning laser beam projection coincides with the theoretical one-line positioning laser beam projection.

10. The method for calibrating a positioning laser beam and a treatment bed in radiotherapy according to claim 1, characterized in that: The method further includes step S500 of removing the laser reference module and the image sensor module.

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