Radiotherapy device, range adjuster and linear actuator

Abstract

A radiotherapy device, a range regulator and a linear actuator. The linear actuator comprises at least one set of transmission module, which is sleeved on an actuating plain shaft and comprises at least two transmission rollers, a supporting block and a clamping block, wherein each transmission roller is arranged non-parallel to the axis of the actuating plain shaft and clamped on the actuating plain shaft, so that the transmission module has a load along the axis of the actuating plain shaft and is configured to drive a transmitted object to move linearly along the axis of the actuating plain shaft, and the transmission roller is connected to the actuating plain shaft in a non-threaded manner. When the load on the transmission module exceeds a threshold, the transmission rollers slide on the actuating plain shaft, so as to achieve overload protection to prevent the transmission module and the actuating plain shaft from being worn or even damaged due to impact force, thereby prolonging the service life of the transmission module and the actuating plain shaft and also ensuring the precision of movement of the linear actuator.

Description

Radiotherapy device, range shifter and linear actuator

[0001] This application claims priority to Chinese patent application No. 202410623158.8, filed on May 20, 2024, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of high-end medical equipment, in particular to a radiotherapy device, a range shifter and a linear actuator. BACKGROUND

[0003] With the progress of medical technology, compared with traditional treatment methods such as surgery, chemotherapy, X-ray radiotherapy, proton radiotherapy can provide more accurate and effective treatment and reduce side effects during treatment, thereby improving the quality of life of patients. Among them, the range shifter is the core component of the compact proton therapy system to realize the energy adjustment of the patient's treatment proton beam. In the compact proton therapy system, the energy switching speed of the range shifter is required to be as fast as possible, and the position control precision is safe and reliable, so it is necessary to control the range adjustment plate quickly and accurately. In order to further improve the position control precision of the range adjustment plate, it is necessary to design a new type of range shifter. SUMMARY

[0004] The purpose of the present application is to provide a radiotherapy device, a range shifter and a linear actuator for ensuring accurate control of the range adjustment plate.

[0005] The purpose of the present application is achieved by adopting the following technical solutions:

[0006] The present application provides a linear actuator, comprising: at least one set of transmission modules for driving a driven object to move in a linear direction, the transmission module is sleeved on an actuating optical axis for realizing rotary motion, the transmission module comprises at least two transmission rollers, a supporting block and a clamping block, each transmission roller is arranged non-parallel to the axis of the actuating optical axis, the two ends of the transmission roller are connected with the supporting block and the clamping block respectively to realize the sliding fit of the two ends of the transmission roller with the supporting block and the clamping block respectively, the transmission roller and the actuating optical axis are connected without threads, the two transmission rollers are clamped on the actuating optical axis, so that the transmission module has a load in the axial direction of the actuating optical axis for driving the driven object to move linearly along the axial direction of the actuating optical axis, the supporting block and the clamping block are both provided with through holes for the actuating optical axis to pass through in the linear direction, and the two transmission rollers are non-parallel and located on both sides of the axis of the actuating optical axis.

[0007] In some alternative embodiments, the transmission module comprises a first transmission module, the first transmission module comprises at least two first transmission rollers, a first supporting block and a first clamping block, the first supporting block has a first bottom wall and a first side wall, the first bottom wall and the first side wall surround to form a first containing space, the first transmission rollers and the first clamping block are arranged in the first containing space, the first clamping block is fixedly connected with the first side wall through a first fastener, and the size of the load of the first transmission module is controlled by adjusting the distance between the first clamping block and the first bottom wall.

[0008] The first transmission roller comprises a first transmission screw and a first bearing and a second bearing arranged at two ends of the first transmission screw respectively, the first transmission screw is clamped on the actuating optical axis, the first bottom wall is provided with a first groove containing at least part of the first bearing, and the first clamping block is provided with a second groove containing at least part of the second bearing.

[0009] In some alternative embodiments, the transmission module further comprises a second transmission module, the second transmission module comprises at least two second transmission rollers, a second supporting block and a second clamping block, the second supporting block has a second bottom wall and a second side wall, the second bottom wall and the second side wall surround to form a second containing space, the second transmission rollers and the second clamping block are arranged in the second containing space, the second clamping block is fixedly connected with the second side wall through a second fastener, and the size of the load of the second transmission module is controlled by adjusting the distance between the second clamping block and the second bottom wall.

[0010] The second transmission roller comprises a second transmission screw and a third bearing and a fourth bearing arranged at two ends of the second transmission screw respectively, the second transmission screw is clamped on the actuating optical axis, the second bottom wall is provided with a third groove containing at least part of the third bearing, and the second clamping block is provided with a fourth groove containing at least part of the fourth bearing.

[0011] In some alternative embodiments, the transmission module further comprises a connecting block, the first bottom wall and the second bottom wall are arranged at two ends of the connecting block respectively and are fixedly connected with the two ends of the connecting block through a third fastener; when the load borne by the transmission module exceeds a threshold value, the transmission roller is used for sliding on the actuating optical axis.

[0012] A range adjuster, comprising:

[0013] A plurality of range adjustment plates, the plurality of range adjustment plates are arranged in parallel with each other, and the range adjustment plates are used for allowing a particle beam to pass through.

[0014] The motion control mechanism comprises a plurality of driving devices and a motion controller for controlling the driving devices, each of the driving devices comprises a driving motor, an actuating optical axis and the linear actuator as claimed in any one of the preceding claims, and the driving devices are used to drive the range adjustment plate to move into or out of the travel path of the particle beam to adjust the total thickness of the range adjustment plate through which the particle beam passes.

[0015] In some optional embodiments, each of the range adjustment plates is provided with one linear actuator on each side, and the linear actuators on the two sides of each of the range adjustment plates are misaligned along the width direction of the range adjustment plate.

[0016] In some optional embodiments, the thicknesses of the range adjustment plates are the same, or the thicknesses of at least some of the range adjustment plates are different, the particle beam is a proton beam, and along the direction of the proton beam, the thickness of the last range adjustment plate through which the proton beam passes is the largest, and the different thicknesses of the range adjustment plates are set according to the Bragg peak width (80%-80%) in water at the nominal energy of the proton beam as the reference X, the equivalent water thicknesses of the range adjustment plates along the direction of the proton beam are in a multiple relationship, and the multiples are 1 / 4X, 1 / 2X, 1X, 2X, 4X and 8X respectively.

[0017] In some optional embodiments, the motion control mechanism further comprises a rack, and the driving devices are respectively arranged on opposite sides of the rack, the two ends of the actuating optical axis are respectively arranged at opposite ends of the rack, the driving motor is arranged at one end of the actuating optical axis, and the linear actuator is connected with the range adjustment plate and is sleeved on the actuating optical axis.

[0018] In some optional embodiments, the motion control mechanism further comprises a first position sensor connected with the driving motor, the first position sensor is used to detect the rotational motion of the driving motor to obtain the position information of the range adjustment plate; and / or,

[0019] The motion control mechanism further comprises a second position sensor connected with the linear actuator, the second position sensor is used to detect the position of the linear actuator to obtain the position information of the range adjustment plate; and / or,

[0020] The motion control mechanism further comprises a third position sensor arranged close to the opposite ends of the rack respectively to limit the movement range of the linear actuator.

[0021] In some optional embodiments, the second position sensor is arranged on the frame, and the linear actuator is provided with an elastic plunger connected with the second position sensor, and the second position sensor acquires the position information of the range adjustment plate through the position of the elastic plunger on the second position sensor; and / or,

[0022] The motion control mechanism further comprises a circuit board, and the first position sensor, the second position sensor, the third position sensor and the driving motor are connected with the circuit board, and the circuit board is connected with the motion controller.

[0023] In some optional embodiments, the range adjustment plate is arranged on the adjusting support, one end of the adjusting support is connected with the linear actuator, and the other end of the adjusting support is connected with the slide rail.

[0024] In some optional embodiments, the range adjustment plate is arranged on the adjusting support, one end of the adjusting support is connected with the linear actuator, and the other end of the adjusting support is connected with the slide rail.

[0025] Adjacent range adjustment plates are provided with gaps to prevent the movement of each range adjustment plate from interfering with each other.

[0026] In some optional embodiments, the adjusting support is provided with a buffer at both ends of the limiting device.

[0027] A radiotherapy device comprises a treatment frame, a particle accelerator, a scanning magnet, an ionization chamber and a range adjuster as claimed in any one of the preceding claims, and the particle accelerator is mounted on the treatment frame and can rotate with the treatment frame.

[0028] The radiotherapy device, the range adjuster and the linear actuator of the present application have at least the following advantages:

[0029] The radiotherapy device, the range adjuster and the linear actuator of the present application are clamped to the actuating optical axis by the transmission roller of the transmission module, so that the transmission module has a load, i.e. bears the load, and then the transmission module drives the range adjustment plate to move. Since the transmission roller is not connected with the actuating optical axis by a thread, but is clamped to the actuating optical axis by the transmission roller, the transmission module can drive the transmission object to move in a linear direction. When the load borne by the transmission module exceeds a threshold value, the transmission roller slides on the actuating optical axis, so as to realize overload protection, avoid the transmission module and the actuating optical axis from being worn or even damaged due to impact force, not only prolong the service life of the transmission module and the actuating optical axis, and then prolong the service life of the linear actuator, but also ensure the moving precision of the linear actuator, and then ensure the precise control of the range adjustment plate. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 is a structural schematic diagram of a linear actuator according to an embodiment of the present application.

[0031] Fig. 2 is an exploded schematic diagram of the linear actuator according to an embodiment of the present application.

[0032] Fig. 3 is a structural schematic diagram of a range adjuster according to an embodiment of the present application from one perspective.

[0033] Fig. 4 is a structural schematic diagram of the range adjuster according to an embodiment of the present application from another perspective.

[0034] Fig. 5 is an exploded schematic diagram of a range adjustment plate and an adjustment support according to an embodiment of the present application.

[0035] Fig. 6 is a comparison diagram of the total thickness of the range adjustment plate required when a particle beam passes through range adjustment plates made of different materials according to an embodiment of the present application.

[0036] Fig. 7 is a comparison diagram of the beam spot size formed when a particle beam passes through range adjustment plates made of different materials according to an embodiment of the present application.

[0037] In the figure: 100, range adjuster; 1, range adjustment plate; 2, motion control mechanism; 21, driving device; 211, driving motor; 212, actuating optical axis; 2121, third end; 2122, fourth end; 213, linear actuator; 2131, first transmission module; 21311, first transmission roller; 213111, first transmission screw; 213112, first bearing; 213113, second bearing; 21312, first support block; 213121, first bottom wall; 213122, first side wall; 213123, first containing space; 213124, first groove; 21313, first clamping block; 213131, second groove; 21314, first fastener; 2132, second transmission module; 21321, second transmission roller; 213211, second transmission screw; 213212, third bearing; 213213, fourth bearing; 21322, second support block; 213221, second bottom wall; 213222, second side wall; 213223, second containing space; 213224, third groove; 21323, second clamping block; 213231, fourth groove; 21324, second fastener; 2133, connecting block; 21331, fifth groove; 21332, third fastener; 2134, elastic plunger; 2135, inductive part; 2136, through hole; 22, first position sensor; 23, second position sensor; 24, third position sensor; 25, motion controller; 26, circuit board; 3, rack; 31, first end; 32, second end; 33, first side; 34, second side; 4, slide rail; 5, adjustment support; 51, hollow part; 52, clamping structure; 6, limiting device. DETAILED DESCRIPTION

[0038] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations can be implemented in any number of manners, and are not limited to the embodiments described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example implementations to those skilled in the art. Like reference numerals refer to like or similar structures throughout the drawings, and repeated description of them will be omitted.

[0039] The words expressing position and direction described in this application are illustrated with the drawings as an example, but changes can also be made according to needs, and the changes made are all included in the protection scope of this application.

[0040] Referring to FIGS. 1-2, the present application provides a linear actuator 213, comprising: at least one set of transmission modules for driving a driven object to move in a linear direction, one end of the transmission module can be connected with the range adjustment plate 1, the transmission module is sleeved on the actuating optical axis 212 and can move along the axial direction of the actuating optical axis 212 to move with the range adjustment plate 1. The driven object can be the range adjustment plate 1.

[0041] Specifically, the linear actuator 213 can include one or more sets of transmission modules, the transmission modules are used to drive the driven object to move in a linear direction, and the multiple sets of transmission modules increase the contact points or contact areas with the actuating optical axis 212, which not only can improve the load capacity of the linear actuator 213, but also can improve the stability between the linear actuator 213 and the actuating optical axis 212, and at the same time, due to the increase of the contact points or contact areas with the actuating optical axis 212, the pressure at the contact points or contact areas can be reduced, thereby reducing the wear between the transmission modules and the actuating optical axis 212, thereby prolonging the service life of the transmission modules and the actuating optical axis 212 and improving the precision of the relative movement between the transmission modules and the actuating optical axis 212.

[0042] Each set of transmission modules can include at least two transmission rollers, a support block and a clamping block, each transmission roller is arranged non-parallel to the axis of the actuating optical axis 212, the two ends of the transmission roller are respectively connected with the support block and the clamping block to realize the sliding fit of the two ends of the transmission roller with the support block and the clamping block, the transmission roller is connected with the actuating optical axis without threads, that is, the transmission roller is arranged between the support block and the clamping block, the two transmission rollers can be approximately X-distributed, the two transmission rollers are cooperated with each other and clamped on the actuating optical axis 212, so that the transmission module has a load in the axial direction of the actuating optical axis 212 for driving the driven object to move linearly along the axial direction of the actuating optical axis 212, the support block and the clamping block are both provided with a through hole 2136 for the actuating optical axis 212 to pass through in the linear direction, and the two transmission rollers are not parallel but located on both sides of the axis of the actuating optical axis 212. That is, the two transmission rollers are clamped on the actuating optical axis 212, and the transmission roller and the actuating optical axis 212 have a certain resisting force, so that the friction force is generated between the transmission roller and the actuating optical axis 212. The friction force not only can keep the position between the transmission roller and the actuating optical axis 212 stable, but also when the actuating optical axis 212 rotates, the actuating optical axis 212 converts the friction force into a thrust force on the transmission roller, so that the transmission roller can move along the axial direction of the actuating optical axis 212, that is, the axial direction, thereby driving the range adjustment plate 1 to move along the axial direction of the actuating optical axis 212. The clamping block can be provided in the shape of a circular gear.

[0043] The transmission roller and the actuating optical shaft 212 can be made of wear-resistant and high-hardness materials. The actuating optical shaft 212 can be made of spring steel, and the surface hardness is preferably greater than or equal to hrc58, so as to prolong the service life of the transmission roller and the actuating optical shaft 212, and avoid the failure of the equipment due to the wear of the transmission roller and the actuating optical shaft 212. In addition, the surface of the transmission roller and / or the actuating optical shaft 212 can be made of a material with high friction coefficient, so as to not only ensure that the transmission module has a load, but also keep the position between the transmission roller and the actuating optical shaft 212 more stable.

[0044] In the present embodiment, referring to FIG. 2, each transmission module includes four transmission rollers, which are uniformly distributed around and clamped to the actuating optical shaft 212, and each transmission roller is arranged non-parallel to the axis of the actuating optical shaft 212, i.e., each transmission roller is arranged intersecting the actuating optical shaft 212, and the axis of each transmission roller and the actuating optical shaft 212 can be approximately X-shaped. The four transmission rollers can improve the friction and stability between the transmission module and the actuating optical shaft 212.

[0045] The linear actuator 213 of the present application is clamped to the actuating optical shaft 212 by the transmission roller of the transmission module, so that the transmission module has a load, and thus the transmission module can drive the range adjustment plate 1 to move. Since the transmission roller and the actuating optical shaft 212 are not threadedly connected, but are clamped to the actuating optical shaft 212 by the transmission roller, i.e., when the load received by the transmission module does not exceed a threshold value, the transmission roller and the actuating optical shaft 212 are connected and relatively moved by the friction therebetween, the transmission roller is used to transmit the driving force in the axial direction on the actuating optical shaft 212 by the static friction between the transmission roller and the actuating optical shaft 212, so as to drive the axial movement of the transmission module; when the load received by the transmission module exceeds the threshold value, the transmission roller slides on the actuating optical shaft 212, so as to realize overload protection, which avoids the wear and even damage of the transmission module and the actuating optical shaft 212 due to the impact force, not only prolongs the service life of the transmission module and the actuating optical shaft 212, and thus prolongs the service life of the linear actuator 213, but also ensures the movement precision of the linear actuator 213, and thus ensures the precise control of the range adjustment plate 1.

[0046] In a specific embodiment, referring to FIG. 2, the transmission module can include a first transmission module 2131, which can include at least two first transmission rollers 21311, a first supporting block 21312, and a first clamping block 21313. In this embodiment, the number of first transmission rollers 21311 is four. The first supporting block 21312 is generally a cuboid, more specifically, a cuboid with an opening. Specifically, the first supporting block 21312 has a first bottom wall 213121 and a plurality of first side walls 213122, the number of the first bottom wall 213121 is one, and the first bottom wall 213121 and the first side walls 213122 surround to form a first containing space 213123, the first transmission rollers 21311 and the first clamping block 21313 can be optionally arranged in the first containing space 213123, the first clamping block 21313 can be fixedly connected with the first side wall 213122 through a first fastener 21314, and the size of the load of the first transmission module 2131 is controlled by adjusting the distance between the first clamping block 21313 and the first bottom wall 213121. Adjusting the distance between the first clamping block 21313 and the first bottom wall 213121 can change the angle between the first transmission rollers 21311 and the actuation optical axis 212, that is, by changing the angle between the first transmission rollers 21311 and the actuation optical axis 212, the size of the load of the first transmission module 2131, i.e., the load bearing, can be changed. The projection of the two first transmission rollers 21311 along the axis direction perpendicular to the actuation optical axis 212 is in the shape of X.

[0047] When the distance between the first clamping block 21313 and the first bottom wall 213121 is reduced, the angle between the first transmission rollers 21311 and the actuation optical axis 212 becomes larger, the friction between the first transmission rollers 21311 and the actuation optical axis 212 increases, and thus the load of the first transmission module 2131 increases. When the distance between the first clamping block 21313 and the first bottom wall 213121 is increased, the angle between the first transmission rollers 21311 and the actuation optical axis 212 becomes smaller, the friction between the first transmission rollers 21311 and the actuation optical axis 212 decreases, and thus the load of the first transmission module 2131 decreases.

[0048] The number of first fasteners 21314 is multiple and uniformly distributed on the first side wall 213122, so that the first clamping block 21313 is more evenly stressed, thereby making the position of the first clamping block 21313 more stable, ensuring the stability of the position of the first transmission rollers 21311, and thus ensuring the stability of the load of the first transmission module 2131.

[0049] The first fastener 21314 abuts against the gear of the first clamping block 21313.

[0050] The first transmission roller 21311 can include a first transmission screw 213111 clamped to the actuating optical axis 212, and a first bearing 213112 and a second bearing 213113 respectively arranged at both ends of the first transmission screw 213111, and the first bottom wall 213121 is provided with a first groove 213124 accommodating at least part of the first bearing 213112, and the first clamping block 21313 is provided with a second groove 213131 accommodating at least part of the second bearing 213113. The first bearing 213112 and the first groove 213124 can be selectively connected in sliding connection, and the second bearing 213113 and the second groove 213131 can be selectively connected in sliding connection, and when the distance from the first clamping block 21313 to the first bottom wall 213121 changes, the angle between the first transmission roller 21311 and the actuating optical axis 212 can be changed. The first bearing 213112 and the second bearing 213113 are spherical bearings.

[0051] The first bearing 213112 and the second bearing 213113 can be spherical or a part of a spherical shape, and the shapes of the first groove 213124 and the second groove 213131 match the shapes of the first bearing 213112 and the second bearing 213113, and when the angle between the first transmission roller 21311 and the actuating optical axis 212 changes, the first bearing 213112 and the second bearing 213113 slide more smoothly, and the spherical bearings can increase the angle range between the first transmission roller 21311 and the actuating optical axis 212.

[0052] Referring to FIG. 2, the transmission module can further include a second transmission module 2132, which can include at least two second transmission rollers 21321, one second support block 21322, and one second clamping block 21323. In this embodiment, the number of second transmission rollers 21321 is four. The second support block 21322 is generally a cuboid, more specifically, a cuboid with an opening. Specifically, the second support block 21322 has one second bottom wall 213221 and second side walls 213222, the second bottom wall 213221 and the second side walls 213222 surround to form a second containing space 213223, the second transmission rollers 21321 and the second clamping block 21323 can be optionally arranged in the second containing space 213223, the second clamping block 21323 can be fixedly connected with the second side walls 213222 through the second fasteners 21324, and the size of the load of the second transmission module 2132 can be controlled by adjusting the distance between the second clamping block 21323 and the second bottom wall 213221. Adjusting the distance between the second clamping block 21323 and the second bottom wall 213221 can change the angle between the second transmission rollers 21321 and the actuation optical axis 212, that is, the size of the load of the second transmission module 2132 can be changed by changing the angle between the second transmission rollers 21321 and the actuation optical axis 212.

[0053] When the distance between the second clamping block 21323 and the second bottom wall 213221 is reduced, the angle between the second transmission rollers 21321 and the actuation optical axis 212 becomes larger, the friction between the second transmission rollers 21321 and the actuation optical axis 212 increases, and thus the load of the second transmission module 2132 increases. When the distance between the second clamping block 21323 and the second bottom wall 213221 is increased, the angle between the second transmission rollers 21321 and the actuation optical axis 212 becomes smaller, the friction between the second transmission rollers 21321 and the actuation optical axis 212 decreases, and thus the load of the second transmission module 2132 decreases.

[0054] The number of second fasteners 21324 is multiple and uniformly distributed on the second side walls 213222, so that the second clamping block 21323 is more evenly stressed, thereby making the position of the second clamping block 21323 more stable, to ensure the stability of the position of the second transmission rollers 21321, and thus ensure the stability of the load of the second transmission module 2132.

[0055] The second fasteners 21324 abut against the gears of the second clamping block 21323.

[0056] The second transmission roller 21321 can include a second transmission screw 213211 and third and fourth bearings 213212 and 213213 respectively arranged at two ends of the second transmission screw 213211, the second transmission screw 213211 is clamped to the actuating optical axis 212, the second bottom wall 213221 is provided with a third groove 213224 accommodating at least part of the third bearing 213212, and the second clamping block 21323 is provided with a fourth groove 213231 accommodating at least part of the fourth bearing 213213. The third bearing 213212 and the third groove 213224 can be optionally connected in sliding connection, and the fourth bearing 213213 and the fourth groove 213231 can be optionally connected in sliding connection. When the distance between the second clamping block 21323 and the second bottom wall 213221 changes, the included angle between the second transmission roller 21321 and the actuating optical axis 212 can be changed. The third bearing 213212 and the fourth bearing 213213 are spherical bearings.

[0057] The third bearing 213212 and the fourth bearing 213213 can be spherical or part of a sphere, and the shapes of the third groove 213224 and the fourth groove 213231 match the third bearing 213212 and the fourth bearing 213213. When the included angle between the second transmission roller 21321 and the actuating optical axis 212 changes, the third bearing 213212 and the fourth bearing 213213 slide more smoothly, and the spherical bearings can increase the range of the included angle between the second transmission roller 21321 and the actuating optical axis 212.

[0058] As an optional way, the transmission module can further include a connecting block 2133, the first bottom wall 213121 and the second bottom wall 213221 are respectively arranged at two ends of the connecting block 2133 and are fixedly connected with the two ends of the connecting block 2133 through third fasteners 21332. In this way, the first transmission module 2131, the second transmission module 2132 and the connecting block 2133 form an integral whole, and the connection between the transmission module and the range adjusting plate 1 is more stable.

[0059] The aperture of the first groove 213124 can be larger than the aperture of the second groove 213131, the aperture of the third groove 213224 can be larger than the aperture of the fourth groove 213231, and the connecting block 2133 is provided with a fifth groove 21331 on both sides facing the first bottom wall 213121 and the second bottom wall 213221. Part of the first bearing 213112 can protrude from the first groove 213124 and be arranged in the fifth groove 21331, and part of the third bearing 213212 can protrude from the third groove 213224 and be arranged in the fifth groove 21331. In this way, the connection between the first transmission module 2131 and the second transmission module 2132 and the connecting block 2133 is more stable.

[0060] Referring to FIGS. 1-5, the present application also provides a range adjuster 100, comprising a plurality of range adjustment plates 1 and a motion control mechanism 2 for adjusting the position of the range adjustment plates 1, the motion control mechanism 2 comprising a linear actuator 213 as described above.

[0061] The shape of the range adjustment plate 1 is, for example, quadrilateral, triangular, circular, or other polygonal, etc., and in the present embodiment, the shape of the range adjustment plate 1 is rectangular. The range adjustment plate 1 is used for the particle beam (not shown) to pass through, the surface of the plurality of range adjustment plates 1 is arranged perpendicular to the direction of travel of the particle beam, that is, the thickness direction of the range adjustment plate 1 is parallel to the direction of travel of the particle beam, so that the particle beam passes through the range adjustment plate 1, and the particle beam can be a proton beam, and the material of the range adjustment plate 1 can be boron carbide, boron-containing polyethylene, or boron-containing polypropylene.

[0062] The boron-containing polyethylene or boron-containing polypropylene material has the advantages of good light transmission, lightweight heat resistance, plasticity, strong corrosion resistance, good wear resistance, high impact resistance, and low price. The boron-containing polyethylene or boron-containing polypropylene material has good light transmission, which can effectively allow the particle beam to pass through the range adjustment plate 1 and will not scatter or absorb the particle beam too much, ensuring the efficiency of the particle beam transmission of the radiotherapy device. The range adjustment plate 1 of the boron-containing polyethylene or boron-containing polypropylene material can reduce the scattering of the particle beam, keep the beam spot of the particle beam from increasing too much, and keep the beam spot of the particle beam as small as possible, thereby ensuring that the particle beam reaches the affected area stably and accurately with a small beam spot.

[0063] The boron-containing polyethylene or boron-containing polypropylene material has a relatively low density, so that the overall weight of the range adjuster 100 is relatively small, and the space occupied is small, thereby reducing the weight and volume of the radiotherapy device.

[0064] The boron-containing polyethylene or boron-containing polypropylene material has high heat resistance, and the range adjustment plate 1 can withstand high temperatures during use of the radiotherapy device, thereby prolonging the service life of the range adjustment plate 1, and the performance of the range adjustment plate 1 can also remain stable, thereby prolonging the service life of the radiotherapy device and the performance of the radiotherapy device can also remain stable.

[0065] The boron-containing polyethylene or boron-containing polypropylene material has good plasticity, and the range adjusting plate 1 can be made into various shapes and sizes by heating and pressing to meet the needs of different radiotherapy equipment. The boron-containing polyethylene or boron-containing polypropylene material range adjusting plate 1 is easy to manufacture, reduces manufacturing costs, and has good thickness consistency, ensuring consistent adjustment performance at different positions of the range adjusting plate 1, improving the stability of the performance of the range adjusting plate 1. At the same time, the flatness of the range adjusting plate 1 is high, the range adjusting plate 1 moves more smoothly, and the adjustment performance at different positions of the range adjusting plate 1 is consistent, improving the stability of the performance of the range adjusting plate 1.

[0066] The boron-containing polyethylene or boron-containing polypropylene material has good corrosion resistance to common chemicals such as acids and bases, and the range adjusting plate 1 is not easily affected by the external environment, and can maintain a long service life.

[0067] The boron-containing polyethylene or boron-containing polypropylene material has good wear resistance and impact resistance. The range adjusting plate 1 needs to be moved frequently during use, and the boron-containing polyethylene or boron-containing polypropylene range adjusting plate 1 has good wear resistance, which can prolong the service life of the range adjusting plate 1 and ensure that the performance of the range adjusting plate 1 remains stable during use. The range adjusting plate 1 may also be subject to accidental collisions during installation or use, and the boron-containing polyethylene or boron-containing polypropylene range adjusting plate 1 has good impact resistance, which prolongs the service life of the range adjusting plate 1 and prevents the range adjusting plate 1 from being damaged by external impact.

[0068] The plurality of range adjusting plates 1 are arranged in parallel with each other, which not only ensures that the adjacent range adjusting plates 1 maintain a fixed distance and prevent collisions during movement, but also ensures that the particle beam does not scatter or change direction when passing through the parallel range adjusting plates 1, ensuring that the particle beam reaches the affected area accurately and stably with a small beam spot.

[0069] The adjacent range adjusting plates 1 have a gap (not shown) between them to prevent the movement of each range adjusting plate 1 from interfering with each other and affecting the smooth operation of the range adjusting plate 1, avoiding the phenomenon of jamming and improving the accuracy of position adjustment of the range adjusting plate 1.

[0070] The motion control mechanism 2 comprises a plurality of driving devices 21 and a motion controller 25, the driving devices 21 and the motion controller 25 can be connected through wires, the driving devices 21 and the motion controller 25 can be wirelessly connected, the motion controller 25 is used for controlling the driving devices 21, each driving device 21 can comprise a driving motor 211, an actuating optical axis 212 and the above-mentioned linear actuator 213, the driving device 21 is used for driving the range adjustment plate 1 to move, the driving device 21 is used for moving the range adjustment plate 1 into or out of the running path of the particle beam, so as to adjust the total thickness of the range adjustment plate 1 through which the particle beam passes. By adjusting the position of the range adjustment plate 1, the total thickness of the range adjustment plate 1 through which the particle beam passes is changed, the energy and the range of the particle beam can be reduced or increased, and the particle beam reaches the diseased part.

[0071] The plurality of driving devices 21 can be independently operated, and one driving device 21 can be used to drive one range adjustment plate 1. Each range adjustment plate 1 is provided with a separate driving device 21, so that each range adjustment plate 1 can be independently adjusted, mutual interference between the plurality of range adjustment plates 1 is avoided, the speed and accuracy of the adjustment of the range adjustment plate 1 are improved, and the combination mode of the range adjustment plate 1 is also increased. Different total thicknesses of the range adjustment plate 1 can be combined by different numbers of range adjustment plates 1, the adjustment range of the range adjustment plate 1 to the particle beam is expanded, and the radiotherapy device can treat tumors in a larger range.

[0072] In some embodiments, one driving device 21 is arranged on each side of each range adjustment plate 1, that is, each range adjustment plate 1 is provided with one linear actuator 213 on each side, and the two linear actuators 213 can make the range adjustment plate 1 move more stably. The linear actuators 213 on the two sides of each range adjustment plate 1 are misaligned along the width direction of the range adjustment plate 1, that is, the linear actuators 213 on the two sides of each range adjustment plate 1 are misaligned, so that the linear actuators 213 on the same side of the range adjustment plate 1 are also misaligned, thereby making the arrangement between the adjacent range adjustment plates 1 more compact, and further making the range adjuster 100 more miniaturized. In alternative embodiments, one driving device 21 is arranged on one side of each range adjustment plate 1, and a slide rail 4 for supporting the range adjustment plate 1 is arranged on the other side along the width direction of the range adjustment plate 1. The slide rail 4 allows the range adjustment plate 1 to slide in the linear direction, so that the range adjustment plate 1 is jointly limited by the driving device 21 and the slide rail 4, and cannot move in a direction other than the movement direction of the range adjustment plate 1, that is, the axis direction of the actuating optical axis 212.

[0073] In one embodiment, the density of the boron-containing polyethylene is 1.95-2.15 g / cm3, and the density of the boron-containing polypropylene is 1.93-2.13 g / cm3. By controlling the density of the boron-containing polyethylene or the boron-containing polypropylene, the content of boron in the boron-containing polyethylene or the boron-containing polypropylene can be controlled. By controlling the content of boron, the energy adjustment effect of the range modulation plate 1 on the particle beam can be improved, thereby reducing the thickness of the range modulation plate 1, and reducing the scattering of the particle beam, keeping the particle beam spot increase small after passing through, thereby ensuring that the particle beam reaches the diseased area stably and accurately with a small spot. It has been verified that the boron-containing polyethylene and the boron-containing polypropylene with the above density can make the range modulation plate 1 have a better adjustment effect.

[0074] Based on the width of the Bragg peak of the particle beam in water, different combinations of the range modulation plate 1 with different thicknesses can be combined to form combinations with different total thicknesses. The range modulation plate 1 with different total thicknesses can make the particle beam reach the diseased area located at different positions.

[0075] In some embodiments, the thicknesses of the plurality of range modulation plates 1 can all be the same, which facilitates the production and installation of the range modulation plate 1, and the combination of the plurality of range modulation plates 1 is simple and facilitates the adjustment of the range modulation plate 1.

[0076] The thicknesses of at least some of the range modulation plates 1 can also be different, that is, the thicknesses of some of the range modulation plates 1 can be the same, the thicknesses of some of the range modulation plates 1 can be different, and the thicknesses of all of the range modulation plates 1 can be different, which can be set according to actual needs. Different thicknesses of the range modulation plate 1 can form a plurality of combinations of the range modulation plate 1 with different total thicknesses through different arrangements, further expanding the adjustment range of the range modulation plate 1 on the particle beam, so that the radiotherapy device can treat tumors in a larger range.

[0077] Each range modulation plate 1 can also be divided into different regions, and the thicknesses of each region can also be different, which can form more combinations of the range modulation plate 1 with different total thicknesses, further expanding the adjustment range of the range modulation plate 1 on the particle beam, so that the radiotherapy device can treat tumors in a larger range.

[0078] The particle beam is a proton beam, and the thickness of the last range modulation plate 1 through which the proton beam passes is the largest in the direction of the proton beam (the direction of the arrow in FIGS. 3 and 4). The thicknesses of the range modulation plates 1 are different and are set according to the Bragg peak width (80%-80%) in water at the nominal energy of the proton beam as a reference X. The equivalent water thicknesses of the range modulation plates 1 are in a multiple relationship along the direction of the proton beam, and the multiple relationships are 1 / 4X, 1 / 2X, 1X, 2X, 4X, and 8X, respectively. The range is adjusted by the combination of the range modulation plates 1 with different thicknesses, so as to achieve the required range in different combinations. The change of the combination state can meet the range adjustment step of the system.

[0079] As an optional mode, the range modulator 100 can further include a rack 3, and the plurality of driving devices 21 are respectively arranged on opposite sides of the rack 3. The two ends of the actuating light axis 212 are respectively arranged at the opposite ends of the rack 3, that is, in the horizontal direction, the plurality of driving devices 21 are respectively arranged on the opposite sides of the rack 3, and in the vertical direction, the two ends of the actuating light axis 212 are respectively arranged at the opposite ends of the rack 3. The driving motor 211 is arranged at one end of the actuating light axis 212, and the linear actuator 213 is connected with the range modulation plate 1 and is sleeved on the actuating light axis 212.

[0080] Specifically, the rack 3 has opposite first and second sides 33 and 34, and opposite first and second ends 31 and 32. The plurality of driving devices 21 are respectively arranged on the first and second sides 33 and 34 of the rack 3. The number of driving devices 21 on the first and second sides 33 and 34 can be selected to be the same, so that the overall structure of the range modulator 100 can be kept more stable. The actuating light axis 212 has opposite third and fourth ends 2121 and 2122. The third end 2121 of the actuating light axis 212 is arranged at the first end 31 of the rack 3, and the fourth end 2122 of the actuating light axis 212 is arranged at the second end 32 of the rack 3. The driving motor 211 is arranged at the third end 2121 of the actuating light axis 212, and the linear actuator 213 is arranged below the driving motor 211. The linear actuator 213 is connected with the range modulation plate 1 and is sleeved on the actuating light axis 212. The driving motor 211 drives the actuating light axis 212 to rotate, and the actuating light axis 212 drives the linear actuator 213 to move up and down along the actuating light axis 212. The linear actuator 213 in turn drives the range modulation plate 1 to move up and down, and moves the range modulation plate 1 into or out of the running path of the particle beam, so as to adjust the total thickness of the range modulation plate 1 through which the particle beam passes.

[0081] In some possible ways, the motion control mechanism 2 can further include a first position sensor 22 connected with the driving motor 211, and the first position sensor 22 is configured to detect the rotational motion of the driving motor 211 to obtain the position information of the range adjustment plate 1. The first position sensor 22 is, for example, a rotary encoder which can be coupled to the driving motor 211. The rotary encoder can detect the number of rotations and the direction of rotation of the driving motor 211 to obtain the position information of the linear actuator 213, and further obtain the position information of the range adjustment plate 1. The rotary encoder can feed back the position information of the range adjustment plate 1 to the motion controller 25, and the motion controller 25 controls the rotation of the driving motor 211 according to the feedback information of the rotary encoder, so as to accurately control the position of the range adjustment plate 1.

[0082] The motion control mechanism 2 can further include a second position sensor 23 connected with the linear actuator 213, and the second position sensor 23 is configured to detect the position of the linear actuator 213 to obtain the position information of the range adjustment plate 1.

[0083] The second position sensor 23 is arranged corresponding to the linear actuator 213, that is, one linear actuator 213 is arranged corresponding to one second position sensor 23. The second position sensor 23 can be connected with the motion controller 25, and the second position sensor 23 is configured to obtain the position information of the range adjustment plate 1. The motion controller 25 controls the rotation of the driving motor 211 according to the feedback information of the second position sensor 23, so as to further accurately control the position of the range adjustment plate 1. The second position sensor 23 can be a sliding rheostat, a tensile displacement sensor, etc. In this embodiment, the second position sensor 23 is a sliding rheostat. The second position sensor 23 is arranged on the rack 3, and the linear actuator 213 is provided with an elastic plunger 2134 connected with the second position sensor 23. The number of the elastic plungers 2134 can be one or more. The second position sensor 23 obtains the position information of the range adjustment plate 1 through the position of the elastic plunger 2134 on the second position sensor 23, that is, the second position sensor 23 can obtain the position information of the range adjustment plate 1 in real time.

[0084] The second position sensor 23 can be a sensor independent of the first position sensor 22, that is, the range adjuster 100 has two or more independent position feedback devices, which ensures the accuracy of the position of the range adjustment plate 1, thereby ensuring the accuracy of the particle beam flow adjustment of the range adjustment plate 1, and further ensuring that the range adjuster 100 can stably operate, avoiding that the damage of one position feedback device leads to the inaccuracy of the position of the range adjustment plate 1, and improving the safety of the operation of the range adjuster 100.

[0085] The motion control mechanism 2 can further comprise third position sensors 24 arranged near opposite ends of the frame 3 respectively to limit the movement range of the linear actuators 213. That is, two third position sensors 24 are arranged near the start position and the end position of each linear actuator 213 respectively, and when the linear actuator 213 moves to the start position or the end position, the driving motor 211 stops running to prevent the linear actuator 213 from exceeding the working range and to avoid damage to the range adjustment plate 1 caused by impact. The third position sensors 24 can be Hall switches, proximity switches, etc., and in this embodiment, the third position sensors 24 are Hall switches. A plurality of Hall switches, for example two, can be arranged in the movement direction of each linear actuator 213, and each linear actuator 213 is provided with a sensing portion 2135, and when the sensing portion 2135 moves to the Hall switch, the Hall switch can feed back the position information of the range adjustment plate 1 to the motion controller 25, and the motion controller 25 controls the driving motor 211 according to the feedback information of the Hall switch to stop the driving motor 211 from running, prevent the linear actuator 213 from exceeding the working range, and avoid damage to the range adjustment plate 1 caused by impact.

[0086] As an optional mode, the first position sensor 22, the second position sensor 23 and the third position sensor 24 can operate independently and do not interfere with each other, and can all feed back the position information of the range adjustment plate 1 to ensure the accuracy of the position measurement of the range adjustment plate 1 and increase the reliability of the system.

[0087] The motion control mechanism 2 can further comprise a circuit board 26, and the first position sensor 22, the second position sensor 23, the third position sensor 24 and the driving motor 211 are connected to the circuit board 26, and the circuit board 26 is connected to the motion controller 25. The motion controller 25 controls the first position sensor 22, the second position sensor 23, the third position sensor 24 and the driving motor 211 through the circuit board 26, which can reduce the use of cables, simplify the cables of the range adjuster 100, and improve the maintainability of the cables.

[0088] In a specific embodiment, the range adjuster 100 can further comprise a plurality of slide rails 4 and an adjusting bracket 5, the slide rails 4 are arranged one by one corresponding to the actuating optical axes 212, the number of the slide rails 4 is the same as the number of the actuating optical axes 212, the range adjustment plate 1 is arranged on the adjusting bracket 5, one end of the adjusting bracket 5 is connected with the linear actuator 213, the other end of the adjusting bracket 5 is connected with the slide rails 4, the range adjustment plate 1 moves more smoothly, stably and improves the accuracy of the movement of the range adjustment plate 1. In this embodiment, the slide rails 4 and the actuating optical axes 212 located on the same side of the rack 3, the actuating optical axes 212 are closer to the outer edge of the rack 3. The adjusting bracket 5 is generally rectangular, the middle part of the adjusting bracket 5 has a hollow part 51, the range adjustment plate 1 is arranged in the hollow part 51 of the adjusting bracket 5 and is fixed by a clamping structure 52, the clamping structure 52 facilitates the installation and disassembly of the range adjustment plate 1, the number of the clamping structure 52 can be multiple, which improves the stability of the range adjustment plate 1.

[0089] In this embodiment, the driving motor 211 is provided with a first position sensor 22, which can be a rotary encoder. The rotary encoder can detect the number of rotations and the direction of rotation of the driving motor 211, that is, the rotary encoder can obtain how many degrees the driving motor 211 rotates. The lead of the transmission module is fixed, and the position of the transmission module can be calculated by the rotation angle of the driving motor 211 and the lead of the transmission module. The elastic plunger 2134 on the transmission module is connected with a second position sensor 23, which can be a sliding rheostat. The second position sensor 23 can obtain the real-time position of the transmission module. If the position of the transmission module calculated by the first position sensor 22 is the same as the position of the transmission module detected by the second position sensor 23, it indicates that the load received by the transmission module does not exceed the threshold. If the position of the transmission module calculated by the first position sensor 22 is different from the position of the transmission module detected by the second position sensor 23, it indicates that the load received by the transmission module exceeds the threshold, and the transmission roller slides or slips on the actuating optical axis 212.

[0090] The range adjuster 100 can further comprise a limiting device 6, which is arranged at opposite ends of the rack 3, that is, the limiting device 6 is arranged at the first end 31 and the second end 32 of the rack 3, and the limiting device 6 is used to limit the range of movement of the range adjustment plate 1. The limiting device 6 can prevent the range adjustment plate 1 from directly impacting the rack 3, and has a protective effect on the range adjustment plate 1. The material of the limiting device 6 can be selected as an elastic material, which has a buffering effect, further reducing the impact force received by the range adjustment plate 1.

[0091] The side of the adjusting support 5 facing the limiting device 6 can also be provided with a buffer, and the material of the buffer can also be elastic material. The elastic material has a buffering effect, and can also reduce the impact force on the range adjusting plate 1.

[0092] The moving range of the range adjusting plate 1 in the vertical direction can be greater than twice the height of the range adjusting plate 1, so that the position adjustment of the range adjusting plate 1 is more convenient.

[0093] Referring to FIG. 6, the range adjusting plates 1 made of polycarbonate, graphite, and boron-containing polyethylene / propylene, respectively, are subjected to simulation tests under the same test conditions, in which the particle beam with an energy of 230 MeV is reduced to zero, and the total thickness of the range adjusting plate 1 required is compared. As can be seen from the figure, the thickness of the range adjusting plate 1 made of boron-containing polyethylene / propylene is the smallest, which indicates that the range adjusting plate 1 made of boron-containing polyethylene / propylene has a better effect on reducing the energy of the particle beam. That is, under the same conditions, the thickness of the range adjusting plate 1 made of boron-containing polyethylene / propylene can be thinner, thereby reducing the weight of the range adjusting plate 1.

[0094] Referring to FIG. 7, the range adjusting plates 1 made of polycarbonate, graphite, and boron-containing polyethylene / propylene, respectively, are subjected to simulation tests under the same test conditions, in which the particle beam with an energy of 230 MeV is adjusted to a particle beam with an energy of 70 MeV, and the beam spot size of the particle beam is compared. As can be seen from the figure, the beam spot size of the particle beam passing through the range adjusting plate 1 made of boron-containing polyethylene / propylene is the smallest, which indicates that the range adjusting plate 1 made of boron-containing polyethylene / propylene can reduce the scattering of the particle beam and keep the beam spot of the particle beam stable, thereby ensuring that the particle beam reaches the affected area with a very small beam spot and accurately.

[0095] The application also provides a radiotherapy device, which comprises a treatment gantry (not shown), a particle accelerator (not shown), a scanning magnet (not shown), an ionization chamber (not shown), and the range adjuster 100 as described above. The radiotherapy device can be configured without a beam transport line. The particle accelerator is installed on the treatment gantry and can rotate with the treatment gantry, which can also be referred to as a rotating gantry. In some possible manners, the radiotherapy device is a proton therapy device, the particle accelerator can be a proton accelerator, and the particle beam can be a proton beam. The particle beam transport system is used to transport the particle beam from the accelerator to the patient's body. The particle beam transport system precisely transports the particle beam to the treatment position through magnetic field control, ensuring accurate positioning and transmission of the particle beam. The particle beam transport system can include components that the particle beam passes through during the transmission process, such as the scanning magnet, the ionization chamber, the adaptive aperture, and the like. The scanning magnet allows the particle beam to move in the X direction and / or the Y direction by appropriately changing the magnetic field, and the X direction and the Y direction are perpendicular to each other. The ionization chamber can be used to measure the dose size and / or position of the beam. The adaptive aperture can also form an adaptive aperture, which can be adaptively adjusted according to the shape and size of the target region, so that the shape and size of the particle beam can match the shape of the tumor. The advantage of such adaptive irradiation is that it can better adapt to irregularly shaped tumors, improving the personalization and targeting of the irradiation plan. The combination of components such as the scanning magnet, the ionization chamber, the range adjuster 100 (also referred to as a range shifter), and the adaptive aperture can provide precise and flexible radiotherapy for patients.

[0096] The accelerator is installed on the treatment gantry and can rotate with the treatment gantry. Such an integrated design can reduce the complexity of the device, because the beam transport line is not needed, thereby simplifying the structure of the device. This also improves the stability of the beam, because the beam transport line inevitably introduces factors that cause beam instability. The radiotherapy device does not need a beam transport line, thereby reducing the maintenance cost and failure rate of the device and improving the stability and reliability of the device. The introduction of unstable factors is reduced, the movement of the beam is more stable, which helps to maintain the stability of the particle beam and ensures accurate irradiation. The aforementioned beam transport line includes components such as dipole magnets and / or quadrupole magnets.

Claims

1. A linear actuator, wherein, The application relates to a transmission module for driving a driven object to move along a linear direction, which comprises at least one set of transmission modules for driving a driven object to move along a linear direction, the transmission module is sleeved on an actuating optical axis for realizing rotary motion, the transmission module comprises at least two transmission rollers, a supporting block and a clamping block, each of the transmission rollers is arranged non-parallel to the axis of the actuating optical axis, the two ends of the transmission roller are connected with the supporting block and the clamping block respectively to realize the sliding fit of the two ends of the transmission roller with the supporting block and the clamping block respectively, the transmission roller and the actuating optical axis are not screw-connected, the two transmission rollers are clamped on the actuating optical axis, so that the transmission module has a load along the axis direction of the actuating optical axis and is used for driving the driven object to move linearly along the axis direction of the actuating optical axis, the supporting block and the clamping block are provided with through holes through which the actuating optical axis passes in the linear direction, and the two transmission rollers are non-parallel and located on the two sides of the axis of the actuating optical axis. The transmission module comprises a first transmission module, the first transmission module comprises at least two first transmission rollers, a first supporting block and a first clamping block, the first supporting block has a first bottom wall and a first side wall, the first bottom wall and the first side wall surround to form a first containing space, the first transmission roller and the first clamping block are arranged in the first containing space, the first clamping block is fixedly connected with the first side wall through a first fastener, and the distance of the first clamping block to the first bottom wall is adjusted to control the size of the load of the first transmission module.

2. The linear actuator of claim 1, wherein, The first transmission roller comprises a first transmission screw and first and second bearings arranged at the two ends of the first transmission screw respectively, the first transmission screw is clamped on the actuating optical axis, the first bottom wall is provided with a first groove containing at least part of the first bearing, and the first clamping block is provided with a second groove containing at least part of the second bearing. The transmission module further comprises a second transmission module, the second transmission module comprises at least two second transmission rollers, a second supporting block and a second clamping block, the second supporting block has a second bottom wall and a second side wall, the second bottom wall and the second side wall surround to form a second containing space, the second transmission roller and the second clamping block are arranged in the second containing space, the second clamping block is fixedly connected with the second side wall through a second fastener, and the distance of the second clamping block to the second bottom wall is adjusted to control the size of the load of the second transmission module.

3. The linear actuator of claim 2, wherein, The second transmission roller comprises a second transmission screw and third and fourth bearings arranged at the two ends of the second transmission screw respectively, the second transmission screw is clamped on the actuating optical axis, the second bottom wall is provided with a third groove containing at least part of the third bearing, and the second clamping block is provided with a fourth groove containing at least part of the fourth bearing. ​ 4. The linear actuator of claim 3, wherein, The transmission module further comprises a connecting block, the first bottom wall and the second bottom wall are respectively arranged at two ends of the connecting block and are fixedly connected with the two ends of the connecting block through third fasteners; when the load borne by the transmission module exceeds a threshold value, the transmission roller is used for sliding on the actuating optical axis.

5. A range adjuster, wherein, Comprise: A plurality of range adjustment plates, a plurality of said range adjustment plates are arranged parallel to each other, said range adjustment plate is used for the particle beam to pass through; A motion control mechanism, said motion control mechanism comprises a plurality of driving devices and a motion controller, said motion controller is used for controlling said driving device, each said driving device comprises a driving motor, an actuating optical axis and a linear actuator as claimed in any one of claims 1-4, said driving device is used to drive said range adjustment plate, so that said range adjustment plate moves into or moves out of the travel path of said particle beam, so as to adjust the total thickness of said range adjustment plate through which said particle beam passes.

6. The range adjuster of claim 5, wherein, Both sides of each said range adjustment plate are respectively provided with one said linear actuator, and the linear actuators on both sides of each said range adjustment plate are misaligned along the width direction of said range adjustment plate.

7. The range adjuster of claim 5, wherein, The thicknesses of a plurality of said range adjustment plates are the same, or at least part of said range adjustment plates have different thicknesses, said particle beam is a proton beam, along the direction of said proton beam, the thickness of the last said range adjustment plate through which said proton beam passes is the largest, and the thicknesses of said range adjustment plates are different, which are set according to the Bragg peak width in water (80%-80%) as the reference X under the nominal energy of the proton beam, the equivalent water thicknesses of a plurality of said range adjustment plates along the direction of the proton beam have a multiple relationship, and the multiples are 1 / 4X, 1 / 2X, 1X, 2X, 4X and 8X respectively.

8. The range adjuster of claim 5, wherein, Further comprising a rack, a plurality of said driving devices are respectively arranged on opposite sides of said rack, both ends of said actuating optical axis are respectively arranged at opposite ends of said rack, said driving motor is arranged at one end of said actuating optical axis, and said linear actuator is connected with said range adjustment plate and is sleeved on said actuating optical axis.

9. The range adjuster of claim 8, wherein, Said motion control mechanism further comprises a first position sensor, said first position sensor is connected with said driving motor, said first position sensor is used for detecting the rotary motion of said driving motor to obtain the position information of said range adjustment plate; and / or, Said motion control mechanism further comprises a second position sensor, said second position sensor is connected with said linear actuator, said second position sensor is used for detecting the position of said linear actuator to obtain the position information of said range adjustment plate; and / or, Said motion control mechanism further comprises a third position sensor, said third position sensor is respectively arranged close to opposite ends of said rack to limit the movement range of said linear actuator.

10. The range adjuster of claim 9, wherein, Said second position sensor is arranged on said rack, an elastic plunger connected with said second position sensor is arranged on said linear actuator, and said second position sensor obtains the position information of said range adjustment plate through the position of said elastic plunger on said second position sensor; and / or, The motion control mechanism further comprises a circuit board, the first position sensor, the second position sensor, the third position sensor and the driving motor are connected with the circuit board, and the circuit board is connected with the motion controller.

11. The range adjuster of claim 8, wherein, Further comprising a plurality of slide rails and adjusting supports, the slide rails are arranged one by one corresponding to the actuating optical axes, the range adjusting plates are arranged on the adjusting supports, one end of the adjusting support is connected with the linear actuator, and the other end of the adjusting support is connected with the slide rail.

12. The range adjuster of claim 11, wherein, Further comprising limiting devices, the limiting devices are arranged at opposite ends of the gantry respectively, and the limiting devices are used for limiting the moving range of the range adjusting plates; or, Adjacent range adjusting plates are left with gaps, so that the movement of each range adjusting plate does not interfere with each other and affect each other.

13. The range adjuster of claim 12, wherein, The adjusting supports are provided with buffer members at both ends towards the limiting devices.

14. A radiotherapy apparatus wherein, The treatment system comprises a treatment gantry, a particle accelerator, a scanning magnet, an ionization chamber and the range adjuster according to any one of claims 5-13, the particle accelerator is installed on the treatment gantry and can rotate with the treatment gantry.

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