Leaf drive mount for a multileaf collimator

Abstract

A mount for an array of leaf drive units corresponding to individual leaf banks of a multi-leaf collimator, the mount comprising: a plurality of separable mounting plates. Each mounting plate comprises an array of mounting holes, each mounting hole arranged to receive a respective one of the leaf drive units.

Description

Technical Field

[0001] This disclosure relates to a blade drive mount for a multi-leaf collimator and a multi-leaf collimator having said mount. This disclosure also relates to a drive mechanism for a multi-leaf collimator and a multi-leaf collimator having said drive mechanism. Background Technology

[0002] Radiation therapy involves generating a beam of ionizing radiation, typically X-rays, electron beams, or other subatomic particle beams. This beam is directed at the cancerous area of ​​the patient and adversely affects the tumor cells, thereby alleviating the patient's symptoms. The beam is delimited so that the radiation dose is maximized in the patient's tumor cells and minimized in healthy cells, thus improving treatment efficiency and reducing side effects suffered by the patient.

[0003] In radiotherapy devices, beam-limiting devices (such as multi-leaf collimators (MLCs)) can be used to delimit the beam. A multi-leaf collimator comprises a large number of elongated, thin blades arranged side-by-side in an array. The blades are typically made of a high atomic number material, usually tungsten, making them substantially opaque to radiation.

[0004] Each leaf can move longitudinally such that its leading edge or tip can extend into or out of the radiation beam. All leaves can be withdrawn to allow the radiation beam to pass through, or all leaves can be extended to completely block the radiation beam. Alternatively, some leaves can be withdrawn while others can be extended to define any desired shape within operational constraints. Thus, the array of leaf tips can be positioned to define a variable edge of the collimator. Multi-leaf collimators typically consist of two rows of such arrays (i.e., leaf rows), each leaf row protruding from opposite sides of the collimator into the radiation beam. Thus, the variable edge provided by the two leaf rows collimates the radiation beam to a selected cross-sectional shape, typically the cross-sectional shape of the target tumor volume to be irradiated. That is, the two leaf rows combine to provide an orifice for shaping the radiation beam into a variable shape.

[0005] The blades of the blade row are driven by an array of blade drive units. Each blade drive unit includes a blade motor, which is arranged to rotate one of the components of the blade drive unit relative to the other. This relative rotational motion is translated into linear motion of the corresponding blade connected to the blade motor at the opposite end of the blade drive unit.

[0006] The desired outcome is that the blade drive unit can be easily installed, removed, and replaced in a multi-blade collimator to improve repair and maintenance efficiency and reduce downtime of radiotherapy equipment. Summary of the Invention

[0007] The aspects and features of the invention are set forth in the appended claims.

[0008] Overview

[0009] In a multi-leaf collimator, the blade drive unit is fixed to a mounting that provides a base from which individual blades are pushed and pulled. This mounting is typically a plate placed behind the rear (or tail) of the blade, which lies in a plane such that the blade's axis of movement is perpendicular to that plane.

[0010] In known multi-leaf collimators, the mounting assembly includes a single mounting plate for receiving all the blade drive units corresponding to the entire blade row. If access to a blade or blade nut is required (e.g., if it is damaged / weary and needs replacement), the entire mounting plate must be removed along with the entire blade row and the corresponding blade drive unit. Once this sub-assembly of the multi-leaf collimator is removed, any blade or blade drive unit can be maintained, repaired, or replaced outside the radiotherapy device. Therefore, accessing any of the various components of the blades and / or blade drive units involves removing a large number of parts from the multi-leaf collimator.

[0011] To address this issue, the mounting plate is divided into multiple sections, each arranged to receive a subset of the blade drive units associated with the blade row. Therefore, only a subset of the blades (and their corresponding blade drive units) of any given blade row needs to be removed and replaced. This provides faster and easier access to any individual blade and / or blade drive unit. Furthermore, fewer components of the multi-leaf collimator need to be removed / replaced during maintenance and repair, thus reducing downtime for radiotherapy equipment.

[0012] Function of the mounting component

[0013] In a fully assembled multi-leaf collimator, multiple blade drive units for driving the blades of one of the two blade rows are mounted in a single mounting assembly, with each blade drive unit installed in a mounting hole in the mounting plate of the assembly. The mounting assembly performs the following functions: (i) providing a common reference point for the blade drive units, enabling individual blades to be reliably positioned relative to each other; and (ii) aligning the corresponding engagement positions of the blade drive units with the tails of their corresponding blades, such that the engagement angle between each blade drive unit and the blade is consistent across the entire blade row.

[0014] The blade drive unit has at least one part that moves relative to another part. Therefore, it can be said that the blade drive unit has a first node (one part of the blade drive unit) and a second node (the other part of the blade drive unit), wherein the second node moves relative to the first node by operation of the blade drive unit. For example, the first node may be part of the blade motor housing of the blade drive unit, and the second node may be part of a blade nut attached to the blade, the blade nut being arranged to move linearly relative to the motor housing when the blade motor is driven (i.e., rotated). Alternatively, the first node may be part of the blade motor housing, and the second node may be part of a blade actuator screw attached to the blade, the blade actuator screw being arranged to move linearly relative to the blade motor housing when the blade motor rotates.

[0015] The blade drive units are mounted to prevent relative linear and rotational movement between the first node of each blade drive unit and the mounting. Therefore, the mounting serves to provide an anchor for the first node of the blade drive unit, causing relative movement between the blade drive unit and the mounting, which in turn results in movement of the individual blades relative to the mounting. The mounting itself can be stationary or movable relative to the base of the multi-blade collimator. Thus, the mounting provides an anchor point for reliable relative positioning of individual blades, which in turn allows for reliable and accurate forming and positioning of the bundle forming orifice.

[0016] Traditional installation components

[0017] In known mounting systems, the mounting plate (the portion of the mounting system that houses the blade drive units) is configured as an integrated component. That is, the mounting plate cannot be disassembled to form a separate part with mounting holes for receiving the blade drive units. Therefore, all blade drive units are coupled to the same single component of the mounting system. In other words, known mounting systems comprise a single mounting plate for receiving all blade drive units of one blade row of a multi-leaf collimator.

[0018] The removal, repair, or replacement of any blade or blade drive unit component can be performed in situ within the multi-leaf collimator. This can be difficult due to the lack of space available for accessing the various components. If a mount with a single conventional mounting plate is used, the repair time can be relatively long due to the density of the motors. Typically, all motor power connectors must be disconnected from the control board, which poses a risk to reliability. Alternatively, the entire blade row, blade drive unit array, and mounting plate can be removed as a whole with the mounting plate before the blade drive unit component (e.g., blade actuator screw or lead screw) is disengaged from its corresponding blade. Therefore, even if only a single blade drive unit or blade requires repair, maintenance, or replacement, a significant amount of other component removal is still necessary.

[0019] Mounting components with detachable mounting plates

[0020] The embodiment includes a mounting for an array of blade drive units corresponding to a single blade row of a multi-leaf collimator, the mounting comprising: a plurality of separable mounting plates, each mounting plate including an array of mounting holes, each mounting hole being arranged to receive a corresponding one of the blade drive units.

[0021] Providing a mounting bracket with a detachable mounting plate allows for the removal of a subset of blade drive units from their mounting locations within the multi-leaf collimator. That is, a subset of blades from a blade row, along with their corresponding blade drive units, can be removed without interfering with other blades and / or blade drive units in the same blade row. Maintenance of individual blade drive units and / or their corresponding blades is easier because the fewer blades and blade drive units in the removed subassemblies of the multi-leaf collimator, the easier it is to manipulate the subassemblies and access the blades and / or blade drive units requiring maintenance. This reduces downtime for radiotherapy equipment.

[0022] Connection between adjacent mounting plates

[0023] In a fully assembled multi-leaf collimator, separable mounting plates are arranged in the same plane and removably connected together. The mounting plates can be connected together by releasable connecting members between adjacent mounting plates or by a common frame, mounting element, or bracket connected to all mounting plates.

[0024] Alternatively or additionally, the mounting plates may include interlocking portions. That is, each mounting plate and its adjacent mounting plates have interlocking portions. Advantageously, this improves the accuracy, reliability, and ease of alignment of the mounting plates.

[0025] In one embodiment, a first mounting plate is coupled to a second mounting plate adjacent to the first mounting plate via selective interlocking of at least a portion of the first mounting plate with at least a portion of the second mounting plate. The interlocking is selective because the second mounting plate can move from a position where at least a portion of the second mounting plate and at least a portion of the first mounting plate are interlocked to a position where there is no interlock between the second and first mounting plates. The interlocking restricts the second mounting plate to linear and / or rotational movement in at least one pair of opposite directions. Advantageously, the interlocking facilitates reliable positioning of the mounting plate, and thus facilitates reliable positioning of the blade drive unit coupled to the mounting plate during repair / replacement, reducing the complexity and cost of repair / replacement.

[0026] Therefore, it can be understood that the mounting plate can be moved from a first position along an axis to a second position, in which the second mounting plate is interlocked with the first mounting plate, and in the second position, the second mounting plate is disengaged from the first mounting plate. In an embodiment, this axis may be the first axis described herein (i.e., parallel to the longitudinal direction of the blade). Advantageously, the second mounting plate can be more easily removed along with the blade drive unit and corresponding blade mounted thereto, while causing minimal interference to the blade drive unit mounted on the first mounting plate and the corresponding blade attached thereto.

[0027] In one embodiment, the interlocking portion of the first and second mounting plates includes a recessed structure on one of the first and second mounting plates and a corresponding protruding structure on the other for insertion into the recessed structure. Advantageously, this provides a simple mechanism for preventing the first mounting plate from moving relative to the second mounting plate along an axis (perpendicular to either side of the protruding or recessed structure), while allowing movement along an axis perpendicular to that axis (e.g., entering / leaving the recessed structure).

[0028] In embodiments, the recessed or protruding structure is elongated, thus allowing movement along an axis perpendicular to both axes (i.e., parallel to the longitudinal direction of the recessed or protruding structure). For example, the recessed structure may be a slot or groove on one of the first and second mounting plates, and the protruding structure may be a structure on the other of the first and second mounting plates corresponding to the slot or groove for engaging the slot or groove.

[0029] Alternatively or additionally, the protruding structure includes a rib or ridge on one of the first mounting plate and the second mounting plate, and the recessed structure is a structure on the other of the first mounting plate and the second mounting plate for engaging the rib or ridge.

[0030] In an embodiment, the interlocking device prevents the first mounting plate from moving relative to the second mounting plate within its own plane, but allows them to move out of that plane to facilitate removal of either mounting plate during maintenance. Hooks, frames, retainers, or supports can be provided to selectively prevent relative movement between the first and second mounting plates along a first axis (i.e., in the direction of blade travel). Therefore, all relative movement between the first and second mounting plates can be prevented during operation of the multi-leaf collimator. For maintenance, one mounting plate can slide out from its interlocked position adjacent to another mounting plate to a position where it is detached from the adjacent mounting plate and can be easily and accurately repositioned back to the same location after maintenance.

[0031] Advantageously, the interlocking allows for easier removal and replacement of the first and second mounting plates from each other, while providing reliable and accurate positioning of the first and second mounting plates relative to each other. Importantly, the mounting plates are accurately aligned, as this affects how the blade drive unit aligns with the blades, which in turn affects the accuracy and reliability of the multi-leaf collimator in use.

[0032] Mounting holes

[0033] Mounting holes are arranged in a two-dimensional array in each mounting plate. This array provides proper alignment between the blade drive units and the corresponding individual blade sections to which they are connected.

[0034] Typically, blades are arranged such that the blade drive units and their connection points are staggered between adjacent blades. This staggering is necessary because the blade drive units can have a maximum width greater than the maximum width of each individual blade to ensure that two adjacent blade drive units do not interfere with each other. Therefore, the mounting holes in the array are arranged in a staggered manner, such that a row of mounting holes is spaced vertically (i.e., along the second axis defined herein) at a distance on the order of the maximum diameter of the blade drive units, and horizontally (i.e., along the third axis defined herein) at a distance on the order of the maximum thickness of the blades.

[0035] Therefore, the two-dimensional array is arranged as a grid comprising rows and columns. Rows extend in a direction passing through the blade row (i.e., generally parallel to the third axis defined herein), and columns extend in a direction passing through that direction and perpendicular to the direction of travel of the blades. The staggering of the mounting holes in each column means that the common center line of the mounting holes in a column is inclined relative to the common center line of the mounting holes in a row. More simply, columns are not perpendicular to rows.

[0036] That is, in the embodiment, the center points of the mounting holes in the array are aligned to form columns extending in a first direction and rows extending in a second direction passing through the first direction, wherein the first direction is inclined to the second direction.

[0037] Advantageously, when configured as described above, the blade drive unit array reduces or minimizes wasted space, and therefore the multi-leaf collimator can be more compact. A more compact multi-leaf collimator can be more easily accommodated and manipulated in radiotherapy equipment.

[0038] To ensure uniform spacing of the rows of mounting holes across the entire blade array, the profile of the mounting plate is configured to allow continuity of the hole pattern from one mounting plate to the adjacent mounting plate. Specifically, at least one mounting plate has a cross-section in its mounting plate plane (i.e., the third plane as defined herein) shaped such that its first edge and its second edge opposite the first edge are substantially parallel to the common centerline of a row of mounting holes. Thus, the mounting holes in rows adjacent to either the first or second edge are uniformly spaced from the edge, and the distance from the edge to the common centerline of the mounting holes is uniform.

[0039] More generally, the center points of the mounting holes in the array are aligned as columns extending in a first direction, and at least one edge of each mounting plate is parallel to the first direction. In an embodiment, the center points of the mounting holes in the array are aligned as columns extending in the first direction and rows extending in a second direction passing through the first direction, wherein the first direction is inclined to the second direction, a first edge of each mounting plate is parallel to the first direction, and a second edge of each mounting plate is parallel to the second direction.

[0040] Alternatively or additionally, the mounting plates include a first mounting plate and a second mounting plate arranged adjacent to the first mounting plate. The center points of the mounting holes in the first mounting plate are arranged in a first series of columns, and the center points of the mounting holes in the second mounting plate are arranged in a second series of columns. A first interval exists between adjacent columns in the first and second series. A second interval exists between the column in the first series closest to the second mounting plate and the column in the second series closest to the first mounting plate, the second interval being equal to the first interval.

[0041] Advantageously, mounting the board does not disrupt the regular spacing between columns in the entire array from one board to the next.

[0042] In one embodiment, the distance between the common center line of the mounting holes in the column adjacent to the first edge of the mounting plate and the first edge is equal to half the distance between the center lines of the adjacent columns of the mounting plate. If the distance between the second edge and the center line of the column adjacent to the second edge is also such, the mounting plates can be interchangeable, because any mounting plate of this design can be used adjacent to another mounting plate of the same design while maintaining the regularity of the spacing between columns across the entire array.

[0043] Typically, six mounting holes are provided per column in the array, but this number can be greater or less than six depending on how the connection points between the blades and the blade drive units are staggered in the blade row. In embodiments, the spacing between the mounting holes in a column and / or row of the array is uniform and sufficient to allow adequate spacing between adjacent blade drive units to allow them to operate without interfering with each other.

[0044] Installation of blade drive unit into mounting plate

[0045] The mounting holes in the mounting plate are arranged to receive portions of the blade drive unit. Typically, the received portion is part of the blade motor housing, as this serves as the aforementioned first node of the blade drive unit. The other components of the blade drive unit (i.e., the internal parts of the blade motor, the blade actuator screw, and / or the associated nut) then move freely relative to the mounting plate.

[0046] Each mounting hole is typically a through hole in the mounting plate, passing between the surfaces of the mounting plate. If through holes are used, a bayonet-type engagement can be employed between the mounting plate and each blade drive unit. In this type of engagement, the blade actuator screw is fed from one side of the mounting plate through the mounting hole to the other until a portion of the blade motor housing engages with the mounting plate. In this configuration, the blade motor is located on one surface of the mounting plate opposite the surface closest to the blade. Therefore, the blade drive unit can be removed from the mounting plate by pulling it backward through the mounting hole in a direction away from the blade (i.e., along the first axis in the second direction described herein). This removal of the blade drive unit allows for the removal and replacement of blade drive units without removing the entire blade row or even a large subset of the blade drive units in a single blade row, as made possible by using a separable mounting plate as described above.

[0047] retainer

[0048] Once the blade drive unit is inserted into the mounting hole, a corresponding retainer, either fixed to or integral with the mounting plate, secures each blade drive unit to the mounting plate. In the case of a mounting assembly with a detachable mounting plate, the mounting assembly includes multiple retainers attached to the mounting plate, each retainer arranged to rigidly connect a corresponding blade drive unit to one of the mounting plates.

[0049] The primary function of the retainer is to prevent linear movement of the first node of the blade drive unit relative to the mounting plate, thus preventing the blade drive unit from being removed from the mounting hole. The retainer also prevents rotational movement of the first node of the blade drive unit, but this function can also be achieved without the retainer by partially interlocking the blade drive unit with the mounting plate.

[0050] In traditional mounting systems, the retainer is a screw mounted in the mounting plate adjacent to the corresponding mounting hole. The screw head is arranged to engage a lip or flange on the blade drive unit (e.g., on the blade motor housing) to push a portion of the blade drive unit onto the surface of the mounting plate and hold it in place. To prevent the screw head from becoming an obstacle to the complete removal of the blade drive unit from the mounting hole, the screw must be completely removed. Once the blade drive unit is placed back into the mounting hole, the screw can be reinserted into its hole in the mounting plate and tightened to re-engage the blade drive unit.

[0051] The problem with this arrangement is that the screws must be completely removed from the mounting plate before the blade drive unit can be removed or replaced. The screws can easily fall off and are difficult to remove and replace, increasing maintenance time and costs, and extending downtime for the radiotherapy equipment.

[0052] Quick release retainer

[0053] The embodiment provides a quick-release attachment between the motor and the mounting plate. A retainer (e.g., a screw) in the mounting plate engages a flange (or lip) on the motor housing to attach the motor to the mounting plate. To remove the motor, the screw is slightly loosened and the motor housing is rotated so that the flange disengages from the screw (a release portion in the flange aligns with the screw head), and the motor detaches from the mounting plate and can be removed without completely removing the screw.

[0054] In one embodiment, the retainer includes: a threaded portion arranged to engage a threaded hole in a mounting plate; and a retaining portion including a retaining surface with an outer diameter larger than that of the threaded portion. The axis of the threaded portion is perpendicular to the plane of the retaining surface. The retaining surface may be an annular surface. If the retainer is a screw or bolt, the retaining portion is the screw head or bolt head itself, and the retaining surface is the underside of the screw head or bolt head. In use, the retaining surface is the portion of the retainer that engages with the blade drive unit and pushes it against the surface of the mounting plate.

[0055] More generally, each retainer is positioned adjacent to a corresponding mounting hole and includes: a head including a retaining surface arranged to face the mounting plate; and a shaft extending from the head and arranged to rotatably engage with the mounting plate such that rotation of the retainer about the axis of the shaft causes the retaining surface to move closer to or further away from the mounting plate.

[0056] The portion of the blade drive unit engaged by the retainer is preferably the blade motor housing. The blade motor housing provides what is referred to herein as the ideal "first node" because it is designed to be stationary, while the other portions of the blade drive unit connected to the blade motor rotate relative to it. However, any other portion of the blade drive unit that meets these criteria can be used to provide the first node.

[0057] In one embodiment, the blade motor housing includes an engaging member arranged to provide a surface that engages with a retaining surface of a retainer, such that the retainer pushes the blade motor housing against a mounting plate. That is, the engaging member can be a flange or a lip. The engaging member can be a mounting flange as described in the specific embodiment. The engaging member is any part of the blade motor housing having a diameter or width larger than the diameter of the mounting hole and a thickness suitable for positioning between the retaining surface of the retainer and the surface of the mounting plate.

[0058] The engaging member has a recess therein, which overlaps with the retaining surface of the retainer when the blade motor housing rotates relative to the mounting plate, allowing the blade motor housing to be removed from the mounting plate without removing the retainer. That is, the blade motor housing can rotate between a first position where the flange engages with the retaining surface and a second position where the recess overlaps with the retaining surface, and the blade drive unit can be completely removed from the mounting hole without removing the retainer from the mounting plate.

[0059] Advantageously, it is not necessary to remove the retainer from the mounting plate in order to remove or replace the blade drive unit.

[0060] More generally, each blade drive unit includes: a motor including a housing, the housing including an engagement member, wherein, in a first rotational position of the housing, the engagement member engages a retainer to attach the housing to a mounting plate; and in a second rotational position of the housing, the engagement member disengages from the retainer.

[0061] An embodiment provides a drive device for a multi-leaf collimator, comprising: a mounting plate for mounting a blade drive unit; a retainer attached to the mounting plate; and a motor configured to actuate the blades of the multi-leaf collimator, the motor including a housing that includes a engaging member. In a first rotational position of the housing, the engaging member engages the retainer to attach the housing to the mounting plate. In a second rotational position of the housing, the engaging member disengages from the retainer.

[0062] In one embodiment, the recess has a curved shape to match the shape of the overlapping portion of the retaining head. However, the recess is not required to have this shape. The recess can have any shape and size, as long as it accommodates the overlapping portion of the retaining head to allow the blade motor housing to move away from the retaining head when the blade motor housing rotates to the second position.

[0063] In one embodiment, each mounting hole has two retainers adjacent to it and spaced 180 degrees apart around the mounting hole.

[0064] In some embodiments, retainers positioned between rows or columns are arranged at approximately equal intervals between mounting holes such that they can hold two blade drive units mounted in adjacent mounting holes. That is, each retainer engages more than one motor housing engagement member. In some embodiments, when positioned at approximately equal intervals between a corresponding number of mounting holes, a single retainer can hold three or even four blade drive units.

[0065] The blade motor housing has a positioning member arranged around its circumference to engage the outer peripheral surface of the retaining head of the retainer. The positioning member is arranged such that when the blade drive unit is fully inserted into the mounting hole and rotates in a direction from the first position to the second position, once the blade drive unit reaches the second position, the positioning member prevents any further rotation of the blade drive unit in that direction.

[0066] More generally, the housing includes a positioning member arranged to engage with a retainer when the motor housing is in the second rotational position, so as to prevent further rotation of the motor housing once the motor housing has reached the second position.

[0067] Advantageously, this allows for easy positioning of the second position without clearly seeing the blade motor housing. This facilitates smooth and reliable removal of the blade drive unit from the mounting holes, thus reducing maintenance time.

[0068] The positioning member may be a protrusion extending from a portion of the blade motor housing, such as a ridge as described in the embodiments of the specific embodiments herein. In the embodiments, the blade motor housing includes a plurality of positioning members corresponding to the number of retainers associated with the mounting holes, each positioning member being arranged to engage with a retaining head in a second rotational position. Attached Figure Description

[0069] The specific embodiments are described below by way of example only and with reference to the accompanying drawings, in which:

[0070] Figure 1 A partially assembled multi-leaf collimator is shown;

[0071] Figure 2 An exploded view of one embodiment of the blade motor and the interface between the blade actuator screw and the blade motor is shown.

[0072] Figure 3 It shows the relationship with Figure 2 The illustration shows different implementations of the blade motor;

[0073] Figure 4a and Figure 4b They are shown respectively Figure 3 An isometric view of the blade motor and its mounting on a mounting plate;

[0074] Figure 5 It is an isometric view of the mounting components; and

[0075] Figure 6 This is an elevation view of the installation component. Detailed Implementation

[0076] MLC components

[0077] Define useful coordinate conventions

[0078] For ease of description, a Cartesian coordinate system is defined in the figures by three mutually perpendicular axes: a first axis (y), a second axis (z), and a third axis (x). The first axis defines a first direction (+y) and a second direction (-y) opposite to the first direction. The second axis defines a third direction (+z) perpendicular to the first direction and a fourth direction (-z) opposite to the third direction. The third axis defines a fifth direction (+x) perpendicular to the first and third directions and a sixth direction (-x) opposite to the fifth direction. The first and second axes define a first plane (yz), the first and third axes define a second plane (xy) perpendicular to the first plane, and the second and third axes define a third plane (xz) perpendicular to both the first and second planes. This coordinate system and convention are used consistently in all figures.

[0079] Figure 1 A partially assembled multi-leaf collimator 100 is shown, which includes a blade row 20, a first blade guide 301 and a second blade guide 302, a blade drive array 40 and a blade drive mounting component 50.

[0080] The blade row 20 comprises an array of blades 200 arranged side-by-side such that the surface of one blade contacts the surface of an adjacent blade. The blades 200 are arranged generally parallel to each other, but a thickness gradient in a first direction from a first edge of each blade 200 to a second edge opposite to the first edge causes the blade row 20 to have a trapezoidal cross-section in a third plane, such as... Figure 1 As shown. Therefore, the plane of the blade 200 positioned in the middle of the blade row 20 is arranged to be approximately parallel to the first plane (yz), but the planes of the other blades on either side of this blade 200 form gradually increasing angles with the first plane (yz) at distances from the center of the blade row 20 in the fifth and sixth directions. The blades 200 are arranged to move relative to each other in the first and second directions. The blades 200 will be described in more detail below.

[0081] The blade drive array 40 includes a plurality of blade drive units 400. Each blade drive unit 400 includes a blade motor 410, a blade actuator screw 430, a blade nut 450, and a blade nut retainer 470. The blade actuator screw 430 is coupled to the blade motor 410 and arranged such that its axis is parallel to a first direction. The blade motor 410 is arranged to rotate the blade actuator screw 430 about its axis (i.e., clockwise and counterclockwise about the first direction). The blade nut 450 is held in place in a blade actuator screw slot 250 in the blade 200 by the blade nut retainer 470, which is fixed to the blade 200. Except for a small amount of relative linear movement between the blade nut 450 and the blade 200 allowed in the third and fourth directions, the blade nut 450 is held stationary relative to the blade 200 by the blade nut retainer 470. The blade nut 450 includes features that interact with the blade 200 to keep the blade nut 450 stationary relative to the blade 200. The blade nut 450 is arranged to receive the blade actuator screw 430 and guide it into the blade actuator screw slot 250. The rotational motion of the blade actuator screw 430 is converted into linear motion of the blade nut 450 relative to the blade actuator screw 430, and thus into linear motion of the blade 200 relative to the blade actuator screw 430.

[0082] The blade drive units 400 are staggered in the first direction such that the blade nut retainer 470 of any blade does not interfere with the blade nut retainer 470 of its adjacent blade 200 on either side. The blade 200 also includes a groove to receive a portion of the blade nut retainer 470 of the adjacent blade 200 that protrudes from the surface of the blade 200. The blade motor 410, blade nut 450, blade nut retainer 470, and groove in the blade are described in more detail below.

[0083] The blade drive mount 50 includes three separate mounting plates 510, 520, and 530 arranged in a plane parallel to a third plane (xz). The blade drive mount includes mounting holes 512 for receiving a blade motor 410 and mounting screws 514 for securing the blade motor 410 to the mounting plates 510, 520, and 530. The blade drive mount 50 and each of its components will be described in more detail below.

[0084] The first blade guide 301 and the second blade guide 302 each include a rectangular frame, which is used to guide and support the blade 200 in the linear motion of the blade 200 entering and leaving the radiation beam in the first direction and the second direction, respectively.

[0085] The complete multi-leaf collimator assembly also includes a second relative arrangement comprising a blade row, blade guides, a blade drive array, and blade drive mounts, which are arranged to be approximately mirror images of the aforementioned assembly relative to a plane parallel to the third plane (xz) and aligned with the center of the axis of the radiation beam.

[0086] In use, the blade drive array drives the blades 200 of its respective blade rows 200 to move into and out of the path of the radiation beam, which passes through an orifice along a fourth direction. This orifice is formed between the leading edges of the blades 200 of one blade row 20 and the leading edges of the blades 200 of the opposing blade row 20. The blades 200 of each blade row 20 can move independently of each other, allowing the shape of the orifice to be changed according to treatment requirements. The orifice acts as a beam shaper by blocking a portion of the radiation beam to redefine its cross-sectional shape in a second plane (yz). That is, the radiation beam passing through the orifice takes on the cross-sectional shape of the orifice in the second plane (yz).

[0087] Multi-leaf

[0088] blade actuator screw

[0089] Figure 2 An exploded view of one embodiment of the blade motor 410 and the interface between the blade actuator screw 430 and the blade motor 410 is shown. The blade actuator screw 430 includes a first connecting member 431 fixed to the end of a non-threaded section 430a. The first connecting member 431 includes a first cylindrical section 431a for receiving and rigidly connecting to the non-threaded section 430a of the blade actuator screw 430. A second cylindrical section 431b, with a diameter smaller than that of the first cylindrical section 431a, extends from the end face of the first cylindrical section 431a along a second direction. The second cylindrical section 431b has a connecting groove 433 formed through its end face.

[0090] blade motor

[0091] exist Figure 2 In the illustrated embodiment, the blade motor 410 includes a blade motor housing 420. The blade motor housing includes a first housing 420a and a second housing 420b removable from the first housing 420a. The blade motor 410 also includes a second coupling member 426, which is fixed to the output shaft of the motor and has a coupling protrusion 427 arranged to interlock with a coupling groove 433 in a second cylindrical section 431b of the first coupling member 431.

[0092] A first housing 420a is arranged to surround the rotor, stator, and commutator of the blade motor 410, but does not surround the second connecting member 426 protruding from the end of the first housing 420a. The first housing 420a includes a main section comprising two cylindrical tubes of the same diameter arranged end-to-end. At a first end of the main section, the housing has a neck with a diameter smaller than that of the main section. The neck includes a flange forming the end of the first housing 420a, from which the second connecting member 426 protrudes in a first direction.

[0093] At the second end of the main section opposite the first end, there is an end cap 423 having the same diameter as the two cylindrical tubes. The end cap 423 has a wiring cut-off portion in a portion of its circumferential region, which allows two wires connected to the internal components of the blade motor 410 to protrude side by side from the end cap 423 radially.

[0094] The second housing 420b includes a cover section 421b arranged to fit on the neck and flange of the first housing 420a. The second housing also includes a neck section 422b with a diameter smaller than that of the cover section 421b, the neck section having the aforementioned blade motor housing mounting flange 425 around its circumference. The second housing 420b is arranged to receive a first connecting member 431 and a second connecting member 426 within its neck section 422b.

[0095] Motor with integrated housing and integrated lead screw

[0096] Figure 3 It shows the relationship with Figure 2 The illustration shows different embodiments of the blade motor 410. Figure 3 In this embodiment, the blade motor 410 includes a blade motor housing 420 having a substantially similar appearance to the first housing 420a and the second housing 420b described above. In this embodiment, the blade motor housing 420 is also arranged to surround the rotor, stator, and commutator. However, the blade actuator screw 430 is not removably coupled to the motor output shaft, but is integrally formed with it. In other words, the blade actuator screw 430 is the motor output shaft. That is, the motor output shaft and the blade actuator screw can be formed from a single integral rod.

[0097] The blade motor housing 420 includes a main section comprising two cylindrical tubes of the same diameter arranged end-to-end. At the first end of the main section, the housing includes a neck with a diameter smaller than that of the main section, and the neck is connected to the main section via a shoulder. The neck includes a mounting flange 425, which is referenced... Figure 2 The flanges described are largely the same. At the second end of the main segment opposite the first end, there exists a flange similar to the reference flange. Figure 2 End cap 423 is described as being roughly the same as the end cap.

[0098] The neck, mounting flange, shoulder connecting the neck to the main section, and cylindrical tube adjacent to the shoulder of the blade motor housing 420 are integral. Alternatively, these parts of the blade motor housing are separate but compressed / jointed together so that they cannot be removed without deformation. That is, these parts of the blade motor housing are formed integrally so that they cannot be removed from each other.

[0099] Installation of the blade motor in the mounting plate

[0100] Figure 4a and Figure 4b They are shown respectively Figure 3 An isometric view of the blade motor 410 and its mounting in a mounting plate 510. Figure 4a The rotational position of the blade motor relative to the mounting plate is shown when the blade motor is inserted into or removed from the mounting hole 512. Figure 4b The rotational position of the blade motor 410 relative to the mounting plate is shown when the blade motor is inserted into the mounting hole 512 and locked in place by the two mounting screws 514.

[0101] As previously described, the blade motor housing 420 is mounted to a corresponding mounting plate 510 by two mounting screws 514, which cooperate with a mounting flange 425 to hold the mounting flange 425 to a second surface of the mounting plate 510. The mounting flange 425 also includes two curved recesses 425a, each arranged to receive the edge of the head of a corresponding mounting screw 514 positioned on one side of a mounting hole 512 in the mounting plate 510. The two curved recesses 425a are positioned opposite each other relative to the central axis of the blade motor housing 420, such that they can be positioned using the corresponding mounting screws 514 positioned on opposite sides of the mounting holes 512 during a specific rotation of the blade motor 410 about a first direction. The curved recesses 425a have a shape and dimensions corresponding to the shape and dimensions of the portion of the head of the mounting screw 514 that generally overlaps with the mounting flange 425.

[0102] Therefore, by rotating the blade motor housing 420 about its axis, the blade motor housing 420 can be in one of two rotational positions relative to the corresponding mounting plate 510. The two rotational positions include a first rotational position (see...). Figure 4a ) and second rotational position (see Figure 4b In the first rotational position, the mounting screw 514 completely overlaps with the corresponding curved recess 425a in the mounting flange 425, and in the second rotational position, the mounting screw 514 overlaps with a portion of the mounting flange 425.

[0103] In the first rotational position, even when the corresponding mounting screw 514 is in place in the mounting plate 510, the end of the blade motor 410 can be inserted into the mounting hole 512 in the mounting plate 510. This is because each curved recess is arranged to receive the edge of the head of the mounting screw 514. After inserting the end of the blade motor 410 into the mounting hole 512, the blade motor housing 420 can be rotated to the second rotational position.

[0104] In the second rotation position, the blade motor housing 420 can be held against the mounting plate 510 by tightening the mounting screw 514 to push the mounting flange 425 against the second surface of the mounting plate 510.

[0105] By loosening the mounting screw 514, the blade motor housing 420 can be rotated back to the first rotational position. In the first rotational position, even when the corresponding mounting screw 514 is in place in the mounting plate 510, the blade motor housing 420 can be removed from the mounting hole 512 in the mounting plate 510, again because the shape and size of each of the two curved recesses 425a are designed to receive the edge of the head of the corresponding mounting screw.

[0106] Return to reference Figure 2 A ridge 429b may be located in the neck section 422b between the cover section 421b and the mounting flange 425. The top surface of the ridge 429b (i.e., the surface away from the outer peripheral surface of the neck section 422b) is flush with the outer peripheral surface of the mounting flange 425. The sides of the ridge cross-section are convex, and the circumferential position of the ridge 429b around the neck section 422b such that one side of the ridge 429b is flush with half of the curved recess 425a. The shape and position of the ridge 429b such that the side of the ridge flush with the curved recess 425a serves as a locating surface for the curved recess 425a. The purpose of the ridge 429b is to increase the cross-section of the neck section 422b, since the wall thickness of the neck section 422b is typically quite thin. Therefore, the ridge 429b gives the neck section 422b greater rigidity. Additionally, ridge 429b acts as a stop (i.e., a positioning device) and restricts rotation of the vane motor housing 420 once it engages below the head of the mounting screw 514. The visibility of the mounting screw 514 is limited because the motor and components obstruct the view. Ridge 429b helps to juxtapose the curved recess 425a and the mounting screw 514. If ridge 429b were not present, rotation of the vane motor housing 420 could continue until the mounting flange unintentionally engages / disengages from the screw head again.

[0107] That is, without the ridge 429b, the mounting flange 425 needs to be visible to ensure that the blade motor housing 420 can be accurately rotated to the first rotational position when the blade motor 410 is inserted into the mounting hole 512. Otherwise, the blade motor 410 must be pulled in the second direction while rotating. However, with the ridge 429b included, the blade motor housing 420 can be rotated until the head of the mounting screw meets the locating surface of the ridge 429b. The first rotational position is then secured, and the blade motor 410 can be removed from the mounting hole 512. The corresponding ridge is located on the opposite side of the neck section 422b to provide a locating surface for the corresponding curved recess 425a on the opposite side of the flange.

[0108] Blade drive mounting components

[0109] Figure 5 and Figure 6 A detailed view shows the blade drive mount 50 and other components of the multi-leaf collimator assembly 100 in place. Figure 5 It is an isometric view. Figure 6 It is an elevation view along the first direction.

[0110] like Figure 5 and Figure 6 As shown, the blade drive mounting assembly includes a first mounting plate 510, a second mounting plate 520, and a third mounting plate 530. The mounting plates 510, 520, and 530 can be separated from each other for easy maintenance and repair.

[0111] Each of the mounting plates 510, 520, and 530 has a first surface parallel to the third plane (xz) and close to the blade 200, and a second surface parallel to the first surface and distant from the blade 200. In use, the blade 200 is positioned between the blade drive mount 50 and the path of the radiation beam, such that the blade drive mount 50 is positioned behind the tail 220 of the blade 200 and intersects the plane of each blade 200.

[0112] Each of the mounting plates 510, 520, and 530 includes a two-dimensional array of mounting holes 512, each having a central axis in a first direction and passing through the mounting plate 510 between a first face and a second face. Each mounting hole 512 is arranged to receive a cylindrical neck of a blade motor housing 420 of a blade motor 410 inserted into the mounting hole 512 from the side of the mounting plate 510 having the second face along the first direction. A blade actuator screw 430 corresponding to the respective blade motor 410 passes through the mounting hole 512 and protrudes from the side of the mounting plate 510 having the first face. A mounting flange 425 of the blade motor housing 420 is arranged to engage with the second face of the mounting plate 510 to prevent the entire neck of the housing from being inserted into the mounting hole 512. Therefore, movement of the blade motor in the first direction is limited by the mounting flange 425.

[0113] Each of the mounting plates 510, 520, and 530 includes an array of threaded holes on its second surface for receiving a corresponding mounting screw 514. When in place in the threaded holes, the mounting screw 514 is arranged to overlap the surface of the mounting flange 425 away from the mounting plate 510 to prevent the blade motor 410 from moving in the second direction.

[0114] The 2D array of mounting holes 512 in each mounting plate 510, 520, 530 comprises three columns. Each column is arranged at an acute angle to the third direction to take into account the staggered positioning of the blade drive units 400 described above. The array is arranged in six rows, and the staggered pattern of the blade drive units 400 repeats once every six blades in the fifth direction.

[0115] like Figure 6 As shown, the sides of the mounting plate are angled approximately parallel to the angled columns. This allows for a consistent spacing of the blade drive units 400 in the fifth direction by allowing a separation of the width of the blades 200 between the first mounting hole 512A in the last row of the last column of a mounting plate 520 and the second mounting hole 512B in the first row of the first column of an adjacent mounting plate 530.

[0116] Mounting screws 514 (i.e., the aforementioned retainers) are arranged on two opposite sides of each mounting hole 512. The mounting screws form a 2D array having rows between the rows of mounting holes 512 and columns between the columns of mounting holes. The mounting screws are positioned such that one mounting screw 514 can interact with a blade motor in the upper row of mounting holes and a blade motor in the lower row of mounting holes. Therefore, the number of mounting screws can be reduced.

[0117] It is understood that small deviations from the terms “parallel,” “perpendicular,” or “in a plane” are permissible when used to describe the relative arrangement of features and components, as long as they do not affect the functionality and / or operational aspects of the multi-leaf collimator module described herein.

[0118] The features described above can be combined in any suitable manner. It should be understood that the above description is merely a description of specific embodiments by way of aspect, and many modifications and variations will be within the scope of those skilled in the art and are intended to be covered by the scope of the appended claims.

Claims

1. A multi-leaf collimator, comprising: A leaf array, which comprises an array of individually movable blades; The array of blade drive units corresponding to the blade row is configured to drive the linear movement of the corresponding blade. A mounting member for an array corresponding to the blade drive unit, the mounting member comprising: Multiple separable mounting plates, each mounting plate including an array of mounting holes, each mounting hole being arranged to receive a corresponding one of the blade drive units; A plurality of retainers are attached to the mounting plate, each of the retainers being arranged to rigidly connect a corresponding blade drive unit to one of the mounting plates; Each of the blade drive units is received in a corresponding mounting hole and includes a motor, the motor including a housing, the housing including a coupling member. In the first rotational position of the housing, the engaging member engages the retaining member to connect the housing to the mounting plate; and In the second rotational position of the shell, the engaging member disengages from the retaining member.

2. The multi-leaf collimator according to claim 1, wherein, The center points of the mounting holes in the array are aligned to form columns extending in a first direction and rows extending in a second direction inclined to the first direction.

3. The multi-leaf collimator according to claim 1, wherein, The center points of the mounting holes in the array of mounting holes are aligned in a column extending in a first direction, and at least one edge of each mounting plate is parallel to the first direction.

4. The multi-leaf collimator according to claim 1, wherein, The center points of the mounting holes in the array are aligned to form columns extending in a first direction and rows extending in a second direction inclined to the first direction. The first edge of each of the mounting plates is parallel to the first direction, and The second edge of each of the mounting plates is parallel to the second direction.

5. The multi-leaf collimator according to claim 1, wherein, The plurality of mounting plates includes a first mounting plate and a second mounting plate arranged adjacent to the first mounting plate. The center points of the mounting holes in the first mounting plate are arranged in a first series of columns, and the center points of the mounting holes in the second mounting plate are arranged in a second series of columns. There is a first interval between adjacent columns in the first series and the second series. There is a second interval between the column closest to the second mounting plate in the first series and the column closest to the first mounting plate in the second series, the second interval being equal to the first interval.

6. The multi-leaf collimator according to claim 1, wherein, Each of the retainers is positioned adjacent to a corresponding one of the mounting holes and includes: The head includes a retaining surface arranged to face the mounting plate; A shaft extending from the head and arranged to rotatably engage with the mounting plate, such that rotation of the retainer about the axis of the shaft causes the retaining surface to move closer to or further away from the mounting plate.

7. The multi-leaf collimator according to claim 1, wherein, The joining member is a flange with a recess.

8. The multi-leaf collimator according to claim 1, wherein, The housing includes a positioning member arranged to engage with the retainer when the housing of the motor is in the second rotational position, so as to prevent further rotation of the housing of the motor once the housing of the motor has reached the second rotational position.

9. The multi-leaf collimator according to any one of claims 1 to 8, wherein, The retainer engages the engagement member of the housing of more than one of the motors.

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