Contactless, redundant position detection of parallel axes in medical devices

A leaf collimator comprising:

• a carriage box;
• a plurality of collimator leaves moveably mounted in the carriage box;
• a plurality of drives coupled to individual collimator leaves of the plurality of collimator leaves, the plurality of drives configured to independently move the individual collimator leaves along a plurality of parallel axes;
• and
• a plurality of contactless sensors mounted to the carriage box and configured to
• generate a first sensing signal indicating a sensed movement of a first subset of the plurality of collimator leaves,
• generate a second sensing signal indicating a sensed movement of a second subset of the plurality of collimator leaves, the second subset of the plurality of collimator leaves including at least one collimator leaf included in both the first subset and the second subset, and
• transmit the first sensing signal and the second sensing signal to a controller, the controller configured to control movement of the at least one collimator leaf included in both the first subset and the second subset based on the first sensing signal and the second sensing signal.

A method comprising:

• sensing using a plurality of contactless sensors changes in positions of a plurality of parts configured to travel along a plurality of axes, the sensing including redundantly sensing positions of each of the plurality of parts by using at least two sensors to sense changes in positions of particular parts included in overlapping subsets of the plurality of parts;
• generating a first sensing signal indicating sensed movement of a first subset of the plurality of parts;
• generating a second sensing signal indicating sensed movement of a second subset of the plurality of parts, the second subset including at least one part also included in the first subset;
• and
• transmitting the first sensing signal and the second sensing signal to a controller configured to control movement of the at least one part included in both the first subset and the second subset based on the first sensing signal and the second sensing signal.