Path planning and collision avoidance for movement of instruments in a radiation therapy environment

A path planning and collision avoidance system for a radiation therapy system having fixed and movable components and selectively delivering therapeutic radiation along a beam axis, the path planning and collision avoidance system comprising:

• a movable patient support configured to support a patient substantially fixed in position with respect to the patient support and controllably position the patient in multiple translational and rotational axes;
• a plurality of external measurement devices arranged to obtain position measurements of components of the radiation therapy system and patient support and of any foreign objects so as to provide location information;
• and
• a controller receiving position information from the plurality of external measurement devices and providing movement commands to the movable patient support to automatically align the patient in a desired pose and determining a corresponding movement envelope wherein the controller evaluates the movement envelope and inhibits movement of the patient support if a collision is indicated else initiates the movement.

A method of registering and positioning a patient for delivery of therapy with a system having fixed and at least one movable component, the method comprising the steps of:

• positioning a patient in an initial treatment pose with a controllable patient positioner;
• externally measuring the location of selected points of the fixed and at least one movable component and of any foreign objects within movement paths of the at least one movable component;
• determining a difference vector between the observed initial patient pose and a desired patient pose;
• determining corresponding movement commands and a movement trajectory for the patient positioner to bring the patient and the system to the desired patient pose;
• and
• comparing the movement trajectory with the measured locations of the selected points of the fixed and at least one movable component and of any said foreign objects;
• and
• inhibiting the movement of the patient positioner if a collision is indicated by the comparison.