System to supervise an automated movement of at least one movable component of an imaging modality within a medical scene to prevent collision between said movable component and other objects within said medical scene, said movable component providing a data stream comprising at least one positional parameter determining said movable components' geometric state in the medical scene, the system comprising, - an interface adapted to read out said positional parameter from said data stream from said movable component, - a memory storing: - dynamic model data representing geometric knowledge of said at least one movable component in the medical scene as a function of said positional parameter of said movable component in said data stream, - stationary model data representing geometric knowledge on all non-movable objects in the medical scene, - a medical scene map, - at least one distance detector fixed at a known position in said medical scene, said known position is stored in said medical scene map, said distance detector providing at least one measured distance between said distance detector and an observed object along a detection axis of said distance detector, - a processor configured to: - calculate said medical scene map from said dynamic model data in combination with said at least one positional parameter, and from said stationary model data, - calculate a calculated distance between said stored position of said distance detector in said medical scene map and a first object along said detection axis of said distance detector in said medical scene map, - compare said at least one measured distance with said calculated distance, such that when the difference between said at least one measured distance and said calculated distance exceeds a threshold value, a trigger signal is sent to said imaging modality. - an interface adapted to read out said positional parameter from said data stream from said movable component, - a memory storing: - dynamic model data representing geometric knowledge of said at least one movable component in the medical scene as a function of said positional parameter of said movable component in said data stream, - stationary model data representing geometric knowledge on all non-movable objects in the medical scene, - a medical scene map, - dynamic model data representing geometric knowledge of said at least one movable component in the medical scene as a function of said positional parameter of said movable component in said data stream, - stationary model data representing geometric knowledge on all non-movable objects in the medical scene, - a medical scene map, - at least one distance detector fixed at a known position in said medical scene, said known position is stored in said medical scene map, said distance detector providing at least one measured distance between said distance detector and an observed object along a detection axis of said distance detector, - a processor configured to: - calculate said medical scene map from said dynamic model data in combination with said at least one positional parameter, and from said stationary model data, - calculate a calculated distance between said stored position of said distance detector in said medical scene map and a first object along said detection axis of said distance detector in said medical scene map, - compare said at least one measured distance with said calculated distance, such that when the difference between said at least one measured distance and said calculated distance exceeds a threshold value, a trigger signal is sent to said imaging modality. - calculate said medical scene map from said dynamic model data in combination with said at least one positional parameter, and from said stationary model data, - calculate a calculated distance between said stored position of said distance detector in said medical scene map and a first object along said detection axis of said distance detector in said medical scene map, - compare said at least one measured distance with said calculated distance, such that when the difference between said at least one measured distance and said calculated distance exceeds a threshold value, a trigger signal is sent to said imaging modality.