Abstract: A phased-network ultrasound transducer for medical use, includes a single support (2) and a group of transducer elements (3) distributed randomly on the surface of the support (2), the transducer elements (3) being fixed. The group includes at least two sub-groups of transducer elements (3), each of the sub-groups having a different geometric point of convergence such as to focus an ultrasound energy in a different coverage volume (4, 5) such that the arrangement of the coverage volumes covers a target volume to be treated. In addition, the transducer includes control elements for controlling the transducer elements (3) independently of one another.