Radiation therapy apparatus
View Patent ↗A radiation therapy apparatus has a multi-leaf collimator device, a driving gear, a torque wire and a driving unit. The multi-leaf collimator device has a pair of collimator components which respectively comprise a plurality of leaves arranged close to one another such that the leaves face one another across an irradiation axis, and configured to set a desired irradiation field by individually moving the leaves. The driving gear is engaged with a gear tooth of the each leaf, respectively. The torque wire is connected to a shaft center of the driving gear, respectively. The driving unit is configured to drive the driving gears through the torque wire.
1. A radiation therapy apparatus comprising:
a multi-leaf collimator device having a pair of collimator components which respectively include a plurality of leaves arranged close to one another such that the leaves face one another across an irradiation axis, and configured to set a desired irradiation field by individually moving the leaves;
a driving gear engaged with a gear tooth of the each leaf, respectively;
a torque wire connected to a shaft center of the driving gear, respectively;
a driving unit configured to drive the driving gears through the torque wire;
a plurality of patterned leaves obtained by forming a predetermined pattern in the leaves in a moving direction along its moving path; and
a moving amount detecting unit configured to detect a moving amount of the each patterned leaf respectively, by obtaining a plurality of positions of the each patterned leaf based on the pattern.
2. The radiation therapy apparatus according to claim 1 , wherein the driving unit comprises a torque motor with a built-in encoder.
3. The radiation therapy apparatus according to claim 1 , wherein the moving amount detecting unit includes:
a light irradiating unit configured to apply light to a fixed point on the moving path of the patterned leaves so as to illuminate a part of the pattern;
an imaging unit configured to obtain an image in an area including the fixed point on the pattern to obtain a fixed-point image; and
a moving amount calculating unit configured to calculate the moving amount of the each patterned leaf based on the fixed-point image obtained with the imaging unit.
4. The radiation therapy apparatus according to claim 1 , wherein the pattern is formed on an outer side of the each leaf, respectively.
5. A radiation therapy apparatus comprising:
a multi-leaf collimator device having a pair of collimator components which respectively include a plurality of leaves arranged close to one another such that the leaves face one another across an irradiation axis, and configured to set a desired irradiation field by individually moving the leaves;
a driving gear engaged with a gear tooth of the each leaf, respectively;
a torque wire connected to a shaft center of the driving gear, respectively;
a driving unit configured to drive the driving gears through the torque wire;
a plurality of magnetic tape-attached leaves obtained by attaching a magnetic tape storing magnetic information to the leaves at regular intervals along the moving direction on its moving path; and
a moving amount detecting unit configured to detect a moving amount of the each magnetic tape-attached leaf respectively, by obtaining a plurality of positions of the each magnetic tape-attached leaf based on the magnetic information.
6. The radiation therapy apparatus according to claim 1 , wherein the leaves have an arc-shaped moving path.
7. The radiation therapy apparatus according to claim 1 , wherein the leaves have a linear moving path.
8. The radiation therapy apparatus according to claim 5 , wherein the driving unit comprises a torque motor with a built-in encoder.
9. The radiation therapy apparatus according to claim 5 , wherein the leaves have an arc-shaped moving path.
10. The radiation therapy apparatus according to claim 5 , wherein the leaves have a linear moving path.