A blade drive device for a multi-leaf collimator

Abstract

This invention discloses a blade driving device for a multi-leaf collimator, comprising: a blade; a blade support base having an open blade mounting cavity, one end of the blade being reciprocally mounted within the blade mounting cavity, and the other end extending from the open end of the blade mounting cavity; and a blade driving mechanism including a drive motor and a transmission mechanism, wherein the transmission mechanism includes a transmission component, the blade being fixedly connected to the transmission component, and the transmission mechanism converting the rotational output of the drive motor into the linear reciprocating motion of the transmission component, the transmission component driving the blade to reciprocate within the blade mounting cavity. The linear reciprocating motion of the transmission component in this invention drives the blade to achieve position adjustment, eliminating the guide rail groove on the existing blade belly, thus ensuring a complete overall blade structure. Furthermore, the direct driving of the blade by the linearly reciprocating transmission component eliminates the slippage of the lead screw, resulting in more accurate displacement and position detection of the blade.

Description

Technical Field

[0001] This invention relates to the field of multi-leaf collimator technology, and more specifically to a blade driving device for a multi-leaf collimator. Background Technology

[0002] The Dynamic Multileaf Collimator (DMLC), also known as a multileaf collimator, is a novel radiotherapy device developed alongside advancements in radiotherapy technology. It effectively meets the requirements of radiotherapy. By moving its leaf blades to create an irradiation field that conforms to the projected shape of the target area, it precisely delivers the dose to the target region, improving tumor treatment outcomes and enhancing patient quality of life. It is suitable for various radiotherapy modalities, such as intensity-modulated radiotherapy (IMRT), volumetric modulated radiotherapy (VMR), helical tomotherapy, and stereotactic radiotherapy. The grating offers advantages such as speed, convenience, high efficiency, large irradiation field, short irradiation time, compact structure, and wide applicability. It has replaced traditional conformal alloy blocks, becoming a key component of radiotherapy and playing a crucial role in improving radiotherapy precision.

[0003] In the mainstream structural design of multi-leaf collimators both domestically and internationally, a motor drives a lead screw via a coupling, which in turn drives the blades. The lead screw passes through the blade's underside, which not only presents technical challenges in blade manufacturing but also, due to the reduction in effective thickness, leads to a negative attenuation effect on X-ray shielding. During treatment, precise control of blade displacement and repeatability is crucial, requiring real-time feedback of blade position information. Currently, the field employs a secondary feedback system based on lead screw drive, which introduces deviations caused by lead screw movement. Eliminating these deviations requires high-precision design and improvement in machining processes, posing technical challenges to production and significantly increasing costs. Most importantly, improving accuracy has reached a bottleneck. Furthermore, due to the inherent mechanical properties of the lead screw, the lead screw length used in mainstream gratings cannot be too long. Excessive length leads to accumulated mechanical deviations from machining processes, and longer lead screws are more difficult to manufacture and prone to breakage.

[0004] For ease of understanding, such as Figure 4 As shown, the upper image shows the state where the blade is fully extended driven by motor 24, at which point the radiation field is closed. The lower image shows the state where the blade is fully returned to its original position driven by motor 24, with the radiation field at its maximum open state. The length of the lead screw 23 shown in the figure cannot be too long, as this would make the manufacturing process difficult and reduce reliability. Therefore, this type of traditional grating is limited in speed. At the same time, the presence of the guide groove 22 makes it difficult for the blade 2 as a whole to shield the radiation in a solid manner, resulting in an increase in thickness compared to this product.

[0005] In view of this, this invention patent is hereby proposed. Summary of the Invention

[0006] To address the shortcomings of traditional multi-leaf collimators that use lead screws for blade driving, this invention provides a blade driving device for multi-leaf collimators, specifically employing the following technical solution:

[0007] A blade drive device for a multi-leaf collimator includes:

[0008] blade;

[0009] The blade support body has an open blade mounting cavity, one end of the blade is reciprocally mounted in the blade mounting cavity, and the other end extends out from the open end of the blade mounting cavity;

[0010] The blade drive mechanism includes a drive motor and a transmission mechanism. The transmission mechanism includes a transmission component. The blade is fixedly connected to the transmission component. The transmission mechanism converts the rotational output of the drive motor into the linear reciprocating motion of the transmission component. The transmission component drives the blade to reciprocate within the blade mounting cavity.

[0011] As an optional embodiment of the present invention, the blade is fixedly connected to the transmission component via a blade movement guide rod. The two ends of the blade movement guide rod are fixedly connected to the blade and the transmission component, respectively. A displacement detection component is installed on the blade movement guide rod. The transmission component drives the blade to reciprocate through the blade movement guide rod. The displacement detection component is used to monitor the movement displacement of the blade.

[0012] As an optional embodiment of the present invention, the displacement detection component is a displacement probe, and a displacement sensing belt is installed on the blade support body. During the process of the transmission component driving the blade movement guide rod to reciprocate, the displacement probe reciprocates along the displacement sensing belt. The blade movement displacement is monitored by positioning the displacement probe at the position corresponding to the displacement sensing belt.

[0013] As an optional embodiment of the present invention, the displacement detection component is a laser rangefinder, and a reflective baffle is installed on the blade support base. The reflective baffle faces the laser beam emitted by the laser rangefinder. During the process of the transmission component driving the blade movement guide rod to reciprocate, the laser rangefinder emits a laser beam towards the reflective baffle to realize the monitoring of the blade movement displacement.

[0014] As an optional embodiment of the present invention, the blade support body has a blade drive mechanism mounting cavity, and the blade drive mechanism mounting cavity and the blade mounting cavity are separated by a partition plate. The partition plate has a motion guide hole, and one end of the blade motion guide rod passes through the motion guide hole and is fixedly connected to the transmission component. A near-blade end limiting component and a far-blade end limiting component are respectively provided on the blade motion guide rod on both sides of the partition plate.

[0015] When the blade extends out of the blade mounting cavity, the distal blade end limiting component abuts against the partition plate to limit the blade extension to its maximum displacement.

[0016] When the blade retracts into the blade mounting cavity, the near-blade end limiting component abuts against the partition plate to limit the blade retraction to its maximum displacement.

[0017] As an optional embodiment of the present invention, the transmission mechanism includes a transmission chain, a driving gear and a driven gear. The transmission chain surrounds the driving gear and the driven gear to form a chain transmission mechanism. The drive motor drives the driving gear to rotate forward / backward. The transmission chain performs reciprocating linear motion under the drive of the driving gear. The transmission component is fixed in the linear motion area of ​​the transmission chain.

[0018] Alternatively, the transmission mechanism includes a transmission belt, a driving pulley, and a driven pulley. The transmission belt surrounds the driving pulley and the driven pulley to form a belt conveyor mechanism. The drive motor drives the driving pulley to rotate forward / reverse. The transmission belt performs reciprocating linear motion under the drive of the driving pulley. The transmission component is fixed in the linear motion area of ​​the transmission belt.

[0019] As an optional embodiment of the present invention, the central axis of the rotation output shaft of the drive motor intersects perpendicularly with the central axis of the drive gear;

[0020] Alternatively, the central axis of the rotation output shaft of the drive motor intersects perpendicularly with the central axis of the drive pulley.

[0021] As an optional embodiment of the present invention, the driving gear or driving pulley is fixedly mounted on the driving shaft, the driving shaft is fixedly mounted with a first bevel gear, and the drive motor is fixedly mounted with a second bevel gear, the first bevel gear and the second bevel gear meshing and transmitting power.

[0022] As an optional embodiment of the present invention, multiple blades are installed side by side in the blade mounting cavity of the blade support body, the transmission belt has a certain width along the blade arrangement direction, multiple blades are fixedly connected to different positions of the transmission belt in the width direction, and multiple mounting positions are evenly arranged in the length direction of the transmission belt corresponding to each blade. When multiple blades are driven by the same blade driving mechanism, the mounting positions of each blade are fixedly connected to adjust, so that a displacement difference is generated between the blades.

[0023] As an optional embodiment of the present invention, the transmission mechanism is a gear and rack transmission mechanism, and the transmission component is the rack of the gear and rack transmission mechanism;

[0024] Alternatively, the transmission mechanism may be a crank-slider mechanism, and the transmission component may be the slider of the crank-slider mechanism.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention discloses a blade driving device for a multi-leaf collimator. The blades are fixedly connected to a transmission component, which performs linear reciprocating motion to adjust the blade position. This eliminates the guide rail grooves on the blade's belly, resulting in a complete blade structure. The linear reciprocating transmission component directly drives the blade, eliminating the lead screw's slippage and improving the accuracy of blade displacement and position detection. Furthermore, the blade driving mechanism allows for the configuration of a high-power, large-volume drive motor, providing stronger driving force and achieving higher speeds. Additionally, the blades in this multi-leaf collimator's blade driving device differ from traditional grating blades in that they lack guide rail grooves and are solid, which is beneficial for radiation attenuation. Attached image description:

[0027] Figure 1 A schematic diagram of the blade driving device for a multi-leaf collimator according to an embodiment of the present invention;

[0028] Figure 2 A diagram illustrating the blade working stroke position of a blade drive device for a multi-blade collimator according to an embodiment of the present invention;

[0029] Figure 3 An example diagram of a transmission belt connecting multiple blades in a blade drive device for a multi-blade collimator according to an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the blade drive method of an existing collimator. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.

[0032] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] See Figure 1 As shown, a blade driving device for a multi-leaf collimator according to this embodiment includes:

[0037] Leaf 2;

[0038] The blade support body 1 has an open blade mounting cavity 13. One end of the blade 2 is reciprocally mounted in the blade mounting cavity 13, and the other end extends out from the open end of the blade mounting cavity 13.

[0039] The blade drive mechanism includes a drive motor 10 and a transmission mechanism. The transmission mechanism includes a transmission component 7. The blade 2 is fixedly connected to the transmission component 7. The transmission mechanism converts the rotational output of the drive motor 10 into the linear reciprocating motion of the transmission component 7. The transmission component 7 drives the blade 2 to reciprocate within the blade mounting cavity 13.

[0040] This embodiment provides a blade driving device for a multi-leaf collimator. The blade 2 is fixedly connected to a transmission component 7. The transmission component 7 performs linear reciprocating motion to drive the blade 2 to achieve position adjustment, eliminating the guide rail groove (e.g., on the belly of the existing blade 2) Figure 4 The designation 22 in the diagram ensures that the overall structure of blade 2 is complete. The blade 2 is directly driven by the linearly reciprocating transmission component 7, eliminating the slippage of the lead screw and making the displacement and position detection of blade 2 more accurate. Furthermore, the blade drive mechanism allows for the configuration of a high-power, large-volume drive motor 10, providing stronger driving force to blade 2 and achieving higher speeds. Additionally, the blade 2 in this embodiment of a multi-leaf collimator differs from traditional grating blades in that it lacks a guide rail groove structure; the blade is a solid whole, which is beneficial for radiation attenuation.

[0041] As an optional implementation of this embodiment, a blade driving device for a multi-leaf collimator is provided. The blade 2 is fixedly connected to the transmission component 7 via a blade movement guide rod 4. The two ends of the blade movement guide rod 4 are fixedly connected to the blade 2 and the transmission component 7, respectively. A displacement detection component 6 is installed on the blade movement guide rod 4. The transmission component 7 drives the blade 2 to reciprocate through the blade movement guide rod 4. The displacement detection component 6 is used to monitor the movement displacement of the blade 2.

[0042] In this embodiment, the blade 2 is fixedly connected to the transmission component 7 via the blade movement guide rod 4. When the blade movement guide rod 4 is fixedly connected, a specific guide groove structure needs to be machined on the connected component. Therefore, the blade 2 can maintain its overall integrity. In addition, the way the movement guide rod 4 is fixedly connected to the blade 2 and the transmission component 7 eliminates the axial movement phenomenon caused by the existing lead screw drive connection.

[0043] Furthermore, in this embodiment, a displacement detection component 6 is installed on the blade motion guide rod 4. The displacement detection component 6 can detect the displacement during the blade 2 position adjustment process so as to adjust the blade 2 to the target position.

[0044] To achieve displacement detection of blade 2, as an optional implementation in this embodiment, the displacement detection component 6 is a displacement probe. A displacement sensing belt 9 is installed on the blade support 13. During the reciprocating motion of the blade movement guide rod 4 driven by the transmission component 7, the displacement probe reciprocates along the displacement sensing belt 9. Monitoring the displacement of blade 2 is achieved by positioning the displacement probe on the displacement sensing belt 9. Therefore, this embodiment of a multi-blade collimator blade driving device, based on the displacement probe on the blade movement guide rod 4, realizes the blade position sensing function, eliminating the axial movement error caused by lead screw-based sensors, and making displacement detection more accurate.

[0045] Specifically, in this embodiment, the displacement sensing strip 9 and the displacement probe use the principle of magnetic induction to achieve displacement measurement.

[0046] In order to realize the motion displacement detection of blade 2, as another optional implementation method of this embodiment, the displacement detection component 6 in this embodiment is a laser rangefinder. A reflective baffle (not shown) is installed on the blade support base 13. The reflective baffle faces the laser beam emitted by the laser rangefinder. During the process of the transmission component 7 driving the blade motion guide rod 4 to reciprocate, the laser rangefinder emits a laser beam towards the reflective baffle to realize the monitoring of the blade motion displacement.

[0047] It should be noted that the blade driving device of the multi-leaf collimator in this embodiment can realize the motion displacement detection of the blade 2 in ways not limited to the two mentioned above. Any technical solution that can realize displacement detection can be used in the patent.

[0048] As an optional implementation of this embodiment, the blade driving device of the multi-leaf collimator of this embodiment has a blade driving mechanism mounting cavity 14 in the blade support base 1. The blade driving mechanism mounting cavity 14 and the blade mounting cavity 13 are separated by a partition plate 16. The partition plate 16 has a motion guide hole. One end of the blade motion guide rod 4 passes through the motion guide hole and is fixedly connected to the transmission component 7. The blade motion guide rod 4 is provided with a near-blade end limiting component 3 and a far-blade end limiting component 5 on both sides of the partition plate 16.

[0049] When the blade 2 extends out of the blade mounting cavity 13, the distal blade end limiting component 5 abuts against the partition plate 16 to limit the blade 2 to extend to its maximum displacement.

[0050] When the blade 2 retracts into the blade mounting cavity 13, the near-blade end limiting part 3 abuts against the partition plate 16 to limit the blade 2 to retract to its maximum displacement.

[0051] In this embodiment, the displacement stroke of the blade 2 is limited by the near-blade end limiting part 3 and the far-blade end limiting part 5, so that the displacement of the blade 2 is adjusted within a certain range.

[0052] As an optional implementation of this embodiment, the transmission mechanism described in this embodiment includes a transmission chain 8, a driving gear 11, and a driven gear 12. The transmission chain 8 surrounds the driving gear 11 and the driven gear 12 to form a chain transmission mechanism. The drive motor 10 drives the driving gear 11 to rotate in the forward / reverse direction. The transmission chain 8 performs reciprocating linear motion under the drive of the driving gear 11. The transmission component 7 is fixed in the linear motion area of ​​the transmission chain 8.

[0053] The transmission mechanism in this embodiment adopts a chain transmission mechanism. By driving the blade movement guide rod 4 through the transmission chain 8, a high-power and large-volume drive motor 10 can be configured to provide stronger power for the blade drive and achieve a higher adjustment speed.

[0054] Alternatively, the transmission mechanism described in this embodiment includes a driving pulley and a driven pulley, and the transmission component is a transmission belt. The transmission belt surrounds the driving pulley and the driven pulley to form a belt conveyor mechanism. The drive motor drives the driving pulley to rotate forward / backward. The transmission belt performs reciprocating linear motion under the drive of the driving pulley, and the transmission component is fixed in the linear motion area of ​​the transmission belt.

[0055] As an optional implementation of this embodiment, the central axis of the rotation output shaft 19 of the drive motor 10 intersects perpendicularly with the central axis of the drive gear 11; or, the central axis of the rotation output shaft 19 of the drive motor 10 intersects perpendicularly with the central axis of the drive pulley. In this way, the arrangement of the drive motor 10 avoids occupying a large space in the width direction of the blade 2, allowing the blades 2 to remain closely arranged even with a relatively small thickness, resulting in better field formation.

[0056] Specifically, in order to achieve the perpendicular intersection of the central axis of the rotation output shaft 19 of the drive motor 10 and the central axis of the drive gear 11; or, in the case where the central axis of the rotation output shaft 19 of the drive motor 10 is perpendicular to the central axis of the drive pulley, the power transmission between the drive motor 10 and the drive gear 11 or the drive pulley is as an optional implementation of this embodiment. In this embodiment, a blade drive device for a multi-leaf collimator is provided, wherein the drive gear 11 or the drive pulley is fixedly mounted on the drive shaft, a first bevel gear 17 is fixedly mounted on the drive shaft, and a second bevel gear 18 is fixedly mounted on the rotation output end 19 of the drive motor 10, and the first bevel gear 17 and the second bevel gear 18 mesh and transmit power.

[0057] As an optional implementation of this embodiment, the blade support base 1 of this embodiment has a motor mounting cavity 15, the drive motor 10 is installed in the motor mounting cavity 15, the motor mounting cavity 15 and the blade drive mechanism mounting cavity 14 are provided with a second partition plate 20, and the rotation output shaft 19 of the drive motor 10 extends through the second partition plate 20 to the position of the drive gear 11 or the drive pulley.

[0058] See Figure 3 As shown in the optional embodiment, this embodiment provides a blade driving device for a multi-blade collimator. Multiple blades 2 are installed side-by-side in the blade mounting cavity 13 of the blade support 1. The transmission belt 21 has a certain width W along the blade 2 arrangement direction. Multiple blades 2 are fixedly connected to different positions on the transmission belt 21 in the width direction. Multiple mounting positions are evenly arranged along the length L direction of the transmission belt 21 corresponding to each blade 2. When multiple blades 2 are driven by the same blade driving mechanism, a displacement difference is generated between the blades 2 by adjusting the fixed mounting positions of each blade 2.

[0059] In this embodiment, multiple blades 2 can be driven by a single drive mechanism, and the displacement difference between blades 2 can be achieved by adjusting the mounting position of the fixed connection of the blades 2.

[0060] As an optional implementation of this embodiment, the blade driving device of a multi-leaf collimator in this embodiment has a gear and rack transmission mechanism, and the transmission component is fixedly installed on the rack of the gear and rack transmission mechanism.

[0061] Specifically, the drive motor 10 drives the gears of the gear and rack transmission mechanism to rotate forward and in reverse, and the rack of the gear and rack transmission mechanism performs reciprocating linear motion under the drive of the gears. The transmission component is fixed on the rack and performs reciprocating linear motion accordingly.

[0062] Alternatively, the transmission mechanism may be a crank-slider mechanism, and the transmission component may be the slider of the crank-slider mechanism.

[0063] In this embodiment, the blades 2 of the multi-blade collimator use the upper and lower surfaces of the blade mounting cavity 13 of the blade support 1 as guide rails. Driven by the blade movement guide rod 4, they reciprocate linearly. The reciprocating linear motion of the blades 2 can form different firing fields, achieving the purpose of conformal imaging. Specific examples are as follows: Figure 2 As shown, Figure 2 -A shows the maximum travel of blade 2, which is the position where the grating is closed. At this point, the field of view is closed. Figure 2 -B indicates an intermediate running state. Figure 2 -C represents the minimum stroke of the grating, which is the state where the grating is fully open, at which point the grating is in its maximum open field state. If the drive motor 10 reverses, the blade 2 can move from the maximum open field position to the minimum open field position, until it is closed.

[0064] In summary, the technical advantages of the blade driving device for a multi-leaf collimator in this embodiment are as follows:

[0065] 1) This invention protects a transmission mechanism that can convert rotation into linear reciprocating motion. The driving force of the drive motor 10 is transmitted to the blade motion guide rod 4 through the transmission mechanism, further driving the blade 2 to reciprocate.

[0066] 2) This invention protects the position sensing function based on the blade motion guide rod 4. This function eliminates the mechanical movement introduced by the traditional lead screw, making the position accuracy feedback more accurate.

[0067] 3) The present invention protects the driving mode based on the blade motion guide rod 4, so that the blade 2 does not need to be chiseled with guide rail grooves for the lead screw to pass through, and the blade is used directly as a solid structure, which is more conducive to enhancing the shielding effect.

[0068] 4) The present invention protects the structural design based on the transmission mechanism, which has higher expandability of the matching drive motor and its related components, and can further improve the blade movement speed.

[0069] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A leaf drive apparatus for a multi-leaf collimator, characterized by, The utility model relates to a kind of blade and blade drive mechanism, comprising: Blade; Blade support body, with open blade installation cavity, one end of the blade is reciprocatingly installed in blade installation cavity, and the other end is stretched by the open end of blade installation cavity; Blade drive mechanism, including drive motor and transmission mechanism, the transmission mechanism includes transmission component, the blade is fixedly connected with transmission component, the transmission mechanism converts the rotation output of drive motor into the linear reciprocating motion of transmission component, and the transmission component drives the blade to reciprocate in blade installation cavity; The blade is fixedly connected with transmission component by blade movement guide rod, two ends of the blade movement guide rod are fixedly connected with blade and transmission component respectively, displacement detection component is installed on the blade movement guide rod, the transmission component drives the blade to reciprocate by blade movement guide rod, and the displacement detection component is used to monitor the displacement of blade movement; The transmission mechanism includes transmission chain, driving gear and driven gear, the transmission chain surrounds driving gear and driven gear to form chain transmission mechanism, the drive motor drives driving gear to rotate forwardly / reversely, the transmission chain reciprocates linearly under the drive of driving gear, the transmission component is fixed in the linear motion area of transmission chain, and the central axis of the rotation output shaft of drive motor intersects with the central axis of driving gear vertically; Alternatively, the transmission mechanism includes transmission belt, driving pulley and driven pulley, the transmission belt surrounds driving pulley and driven pulley to form belt transmission mechanism, the drive motor drives driving pulley to rotate forwardly / reversely, the transmission belt reciprocates linearly under the drive of driving pulley, the transmission component is fixed in the linear motion area of transmission belt, and the central axis of the rotation output shaft of drive motor intersects with the central axis of driving pulley vertically; The driving gear or driving pulley is fixedly installed on driving shaft, the first bevel gear is fixedly installed on the driving shaft, the second bevel gear is fixedly installed on the rotation output end of drive motor, and the first bevel gear and the second bevel gear are engaged to drive.

2. The leaf drive apparatus of a multi-leaf collimator according to claim 1, wherein, The displacement detection component is displacement probe, displacement sensing tape is installed on the blade support body, the displacement probe reciprocates along displacement sensing tape in the process that the transmission component drives blade movement guide rod to reciprocate, and the displacement of blade movement is monitored by positioning the position of displacement probe on displacement sensing tape.

3. The leaf drive apparatus of a multi-leaf collimator according to claim 1, wherein The displacement detection component is laser range finder, light-reflecting baffle is installed on the blade support body, the light-reflecting baffle faces the laser beam emitted by laser range finder, and the laser range finder emits laser beam to light-reflecting baffle in the process that the transmission component drives blade movement guide rod to reciprocate, so as to monitor the displacement of blade movement.

4. The leaf drive apparatus of a multi-leaf collimator according to claim 1, wherein The blade support seat has a blade driving mechanism installation cavity inside, the blade driving mechanism installation cavity and the blade installation cavity are separated by a partition plate, the partition plate has a movement guide hole, one end of the blade movement guide rod penetrates through the movement guide hole and is fixedly connected with the transmission component, the blade movement guide rod has a near-blade-end limiting component and a far-blade-end limiting component arranged on both sides of the partition plate respectively: When the blade extends out of the blade installation cavity, the far-blade-end limiting component abuts against the partition plate to limit the longest displacement of the blade extension; When the blade retracts into the blade installation cavity, the near-blade-end limiting component abuts against the partition plate to limit the longest displacement of the blade retraction.

5. The leaf drive apparatus of a multi-leaf collimator according to claim 1, wherein Multiple blades are installed side by side in the blade installation cavity of the blade support seat, the multiple blades are fixedly connected at different positions in the width direction of the transmission belt, multiple installation positions are uniformly arranged on the length direction of the transmission belt corresponding to each blade, when the multiple blades are driven by the same blade driving mechanism, the displacement difference between the blades is generated by adjusting the installation positions to which each blade is fixedly connected.

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