Leaf actuator for a multi-leaf collimator

Patent metadata

Field	Value
Publication number	US-12558568-B2
Application number	US-202117906153-A
Country	US
Kind code	B2
Filing date	Mar 11, 2021
Priority date	Mar 13, 2020
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

A leaf unit for a multi-leaf collimator may comprise a leaf, a leaf actuator screw, a rotatable part threadably engaged with the leaf actuator screw, a leaf actuator motor, and a supporting bracket. The leaf actuator screw including a first end fixedly attached to the leaf and the leaf actuator motor being coupled to the rotatable part. The support bracket comprising a first portion with a first opening arranged to receive and support the leaf actuator motor and a second portion with a second opening including a bearing. The second opening being arranged to receive and support the rotatable part. A center of the first opening is aligned with that of the second opening so that an axis of the leaf actuator motor and an axis of the rotatable part of each leaf actuator are colinear.

First claim

The invention claimed is:

1 . A leaf unit assembly for a multi-leaf collimator, the leaf unit assembly comprising:
a leaf; a leaf actuator screw having a first end fixedly attached to the leaf; a rotatable part threadably engaged with the leaf actuator screw; a leaf actuator motor coupled to the rotatable part; and a support bracket comprising: a first portion comprising a first opening arranged to receive and support the leaf actuator motor; and a second portion comprising a second opening having a bearing therein, arranged to receive and support the rotatable part, wherein a center of the first opening is aligned with that of the second opening so that an axis of the leaf actuator motor and an axis of the rotatable part of each leaf actuator are collinear.

2 . The leaf unit assembly according to claim 1 , wherein the first end of the leaf actuator screw is coupled to the leaf so as to prevent relative rotational motion between the leaf and the leaf actuator screw around an axis of the leaf actuator screw.

3 . The leaf unit assembly according to claim 1 , wherein the leaf actuator screw has a second end opposite the first end, wherein the rotatable part is a tube that envelops at least a portion of the second end of the leaf actuator screw.

4 . The leaf unit assembly according to claim 1 , wherein, upon rotation of the rotatable part relative to the leaf, the rotatable part is configured to cause a relative linear motion between itself and the leaf.

5 . The leaf unit assembly according to claim 1 , wherein the leaf actuator screw is configured to move between an extended position in which over half of the leaf actuator screw is outside the rotatable part, and a retracted position in which over half of the leaf actuator screw is enveloped by the rotatable part.

6 . The leaf unit assembly according to claim 1 , wherein the rotatable part comprises a plurality of slots, wherein each slot of the plurality of slots extend around a portion of a circumference of the rotatable part, and wherein each slot of the plurality of slots are offset from each other in a direction of an axis of the rotatable part.

7 . The leaf unit assembly according to claim 1 , wherein the rotatable part has a first end threadably engaged with the leaf actuator screw and a second end coupled to the leaf actuator motor.

8 . The leaf unit assembly according to claim 1 , wherein the leaf actuator screw has at least one of a diameter of up to 2 mm or a length of at least 100 mm.

9 . A multi-leaf collimator for a radiotherapy device, the multi-leaf collimator comprising:
a leaf bank including a plurality of leaf unit assemblies wherein each leaf unit assembly of the plurality the leaf unit assemblies comprises: a leaf, a leaf actuator screw having a first end fixedly attached to the leaf, and a rotatable part threadably engaged with the leaf actuator screw; a leaf actuator motor coupled to the rotatable part; and a support bracket comprising: a first portion comprising a first opening arranged to receive and support the leaf actuator motor; and a second portion comprising a second opening having a bearing therein, arranged to receive and support the rotatable part, wherein a center of the first opening is aligned with that of the second opening so that an axis of the leaf actuator motor and an axis of the rotatable part of cach leaf actuator are collinear, and wherein a rotational movement of each leaf relative to each other is restricted such that rotation of each rotatable part imparts linear motion of the respective leaf actuator screw and leaf relative to the rotatable part.

10 . The multi-leaf collimator according to claim 9 , wherein the rotatable part of each leaf unit assembly is operable to move a respective leaf in a linear motion independently of any other leaf in the leaf bank.

11 . The multi-leaf collimator according to claim 9 , wherein the first portion is removably attached to the second portion.

12 . A radiotherapy device comprising:
a multi-leaf collimator, the multi-leaf collimator comprising: a leaf bank including one or more leaf assembly units, wherein each of the one or more leaf assembly units comprises: a leaf; a leaf actuator screw having a first end fixedly attached to the leaf; a rotatable part threadably engaged with the leaf actuator screw; a leaf actuator motor coupled to the rotatable part; and a support bracket comprising: a first portion comprising a first opening arranged to receive and support the leaf actuator motor; and a second portion comprising a second opening having a bearing therein, arranged to receive and support the rotatable part, wherein a center of the first opening is aligned with that of the second opening so that an axis of the leaf actuator motor and an axis of the rotatable part of each leaf actuator are collinear.

13 . The radiotherapy device of claim 12 , wherein a rotational movement of each leaf relative to each other is restricted such that rotation of each rotatable part causes linear motion of the respective leaf actuator screw and leaf relative to the rotatable part.

14 . The radiotherapy device of claim 12 , wherein the rotatable part of each leaf unit assembly is operable to move a respective leaf in a linear motion independently of any other leaf in the leaf bank.

Assignees

• Elekta ltd

Inventors

• Broad Martin

Classifications

• A61N5/1048

  Monitoring, verifying, controlling systems and methods · CPC title

• A61N5/1045 Primary

  using a multi-leaf collimator, e.g. for intensity modulated radiation therapy or IMRT · CPC title

• G21K1/046 Primary

  varying the contour of the field, e.g. multileaf collimators · CPC title

• A61N5/1042 Primary

  with spatial modulation of the radiation beam within the treatment head · CPC title