The present disclosure generally relates to a multi-leaf collimator. The multi-leaf collimator may include a set of leaves installed in a cavity, each leaf of the set of leaves having a length along a first direction. At least a portion of the set of leaves may extend beyond the cavity along the first direction. The set of leaves may be arranged along a second direction, the second direction being different from the first direction. A length of a target leaf of the set of leaves may be less than a length of a reference leaf of the set of leaves. The target leaf may be located in an end portion of the set of leaves along the second direction. The length of the set of leaves may conform to the shape of a maximum therapeutic radiation field.

The present disclosure may provide a collimator assembly. The collimator assembly may include a multi-leaf collimator (MLC) situated in a first plane and at least one block situated in a second plane different from the first plane. The MLC may include at least one first group of leaves and at least one second group of leaves opposing each other and being moveable along a first direction. One of the at least one block may be located at a position corresponding to an end of the at least one first group of leaves. Projection of one of the at least one block along a second direction may partially overlap projection of the at least one first group of leaves along the second direction.

The present disclosure relates to a motion guidance assembly for guiding the motion of a collimator device. The motion guidance assembly may include a first pair of flexible plates connected to the collimator device. The first pair of flexible plates may be deformable in a direction perpendicular to an opening of the collimator device. A deformation of the first pair of flexible plates may guide the motion of the collimator device based on a driving force.

The present disclosure relates to a collimator for radiation generating apparatus, attached to a radiation generating apparatus, the collimator comprising: a frame fixed to the radiation generating apparatus and formed in a ring shape; and a shielding adjustment part provided with a plurality of shielding wings, one end of the shielding wings being hinged to the frame such that, when rotated, the other end of the shielding wings enters into a center of the frame, and the each one end of the shielding wings being disposed to be spaced apart on the frame, wherein the shielding wing is made of a radiation shielding metal. Accordingly, it is possible to easily adjust the diameter of radiation field made in a circular shape.

A photon source emits a flattening filter-free photon beam. A control circuit operably couples to a multi-layer multi-leaf collimator that is disposed between the photon source and a treatment area of a patient. The control circuit automatically arranges operation of some, but not all, of the layers of the multi-layer multi-leaf collimator to serve as a virtual flattening filter with respect to the flattening filter-free photon beam emitted by the photon source. By one approach, another of the layers of the multi-layer multi-leaf collimator serves to form a treatment aperture corresponding to a shape of the treatment area of the patient. By one approach the control circuit comprises an integral part of a treatment platform (as versus a dedicated treatment planning platform) and can carry out most or even essentially all of the planning steps that lead to administration of the treatment to a patient.

A method of measuring a rotational position of an assembly with circumferential ferromagnetic teeth includes applying an excitation signal for a cycle to an actuator, the cycle causing a first rotational displacement of a first ferromagnetic tooth from a first rotational position to a second rotational position and a second rotational displacement of a second ferromagnetic tooth from the second rotational position to a third rotational position. The method further includes measuring a plurality of first signal outputs from a magnetoresistive sensor during the cycle; determining one or more signal offset values based on the plurality of first signal outputs; applying the signal excitation for a portion of a second cycle to the actuator; measuring second signal outputs from the magnetoresistive sensor; generating corrected signals by modifying the second signal outputs with the signal offset values; and, based on the corrected signals, determining a rotational position of the assembly.

A multileaf collimator includes a plurality of movable leaves for shaping a radiotherapy beam, wherein each leaf is independently movable in a same linear travel direction. Each leaf includes a linear array of magnets disposed on a measurement surface of the leaf and an array of magnetoresistive sensors that is disposed proximate the measurement surfaces of the leaves.

A multi-layer multi-leaf collimation system includes at least a two layers of collimation leaves. The first multi-leaf collimator layer is configured to primarily perform a first function to affect a radiation beam traveling from a radiation source to a target and a second multi-leaf collimator layer is configured to primarily perform a second function, different from the first function, to affect the radiation beam for the administration of a treatment plan.

Methods and systems for correcting position errors for a multi-leaf collimator (MLC) are provided. A method may include determining a first position for each of the plurality of leaves. The information associated with the first position may include a first movement direction and a first angle. A movement of the each of the plurality of leaves along the first movement direction may be configured to move toward or away from a center of the radiation field. The method may also include determining an offset value associated with the first position based on the first angle and the first movement direction; and determining a target position of the each of the plurality of leaves based on the offset value.

An imaging system comprising a radiation source and radiation thereby; a detector having an input surface; a monitor configured to display images detected by the detector; a Graphical User Interface (GUI) for determining at least one Region of Interest (ROI) on a displayed image; and a collimator comprising means for modulating intensity of the radiation according to the at least one ROI; wherein the GUI comprises means for displaying detected images and means for determining shape and location of the at least one ROI.