The device has a mechanical structure e.g. articulated arm, articulated on a support on which an instrument/tool i.e. echographic probe (S), is fixed. A motor unit (13) actuates the structure based on a number of degrees of freedom lower than a number of degrees of freedom provided by the structure to the probe. An automatic controller automatically controls the motor unit to facilitate the satisfaction of a constraint based on speed and/or position parameters of the probe. The motor unit does not entirely satisfy the constraint, independent from handling of the probe by an operator. The articulated arm is Phantom omni(RTM: haptic) robot. An independent claim is also included for an imaging assembly.
