Disclosed is a computer-implemented medical data processing method for controlling the geometric status of a mechatronic articulable arm, the method comprising executing, on at least one processor of at least one computer, steps of: a) acquiring (S1.1), at the at least one processor, current device position data describing a current relative position between a utility element of the mechatronic articulable arm and anatomical body part of a patient's body; b) acquiring (S1.2), at the at least one processor, current geometric status data describing a current geometric status of the mechatronic articulable arm defined by a set of at least one current spatial relationship between connected elements of the mechatronic articulable arm; c) acquiring (S1.3), at the at least one processor, changed device position data describing a changed relative position between the utility element and the anatomical body part which is a relative position that has changed compared to the current relative position; d) acquiring (S1.4), at the at least one processor, device definition data describing the movability of the mechatronic articulable arm; e) determining (S1.5), by the at least one processor and based on the current device position data and the current geometric status data and the changed device position data and the device definition data, changed geometric status data describing a changed geometric status of the mechatronic articulable arm defined by a set of at least one changed spatial relationship between the connected elements, wherein the set of at least one changed geometric relationship is different from the set of at least one current spatial relationship; f) determining (S1.6), by the at least one processor and based on the current geometric status data and the changed geometric status data, instruction data describing an instruction for changing the geometric status of the mechatronic articulable arm from the current geometric status to the changed geometric status.