In order to obtain a predetermined ultrasonic wave field in a homogeneous internal part of a medium masked by an aberrating barrier, an ultrasonic lens is interposed between the emitting ultrasonic probe and the aberrating barrier. The ultrasonic lens is calculated by using a model of the medium comprising a mapping of ultrasonic wave propagation properties obtained from actual imaging of the medium such that when the ultrasound probe sends a predetermined ultrasonic wave, said predetermined wave generates the predetermined objective ultrasonic wave field in the medium.
