is used to provide feedback to the operator about the amplitude of received ultrasonic signals to control the probe 39 s applied force the electronic unit 188 provides initial series of wave packets to transmitting transducer acquires and processes the signals from the receiving transducer acquires the data from the positioning system and communicates in real time with the computer 189 fig2 shows two orthogonal cross sections of a broadband ultrasonic transducer in accordance with the present invention frontal 190 and lateral 191 cross sectional views are represented the preferred design of a transducer consists of 1 a miniature piezoceramic transducer 192 shaped as a prism with inclined facets pointing towards the bone and mounted on a metal support rod 193 which is a hot electrode connected to the output of the electronic unit 2 a compound fill up 194 for example an epoxy compound 3 a metal shield housing 195 4 and an electrical insulation 196 for example a teflon cylinder a silver wire 199 connects the piezoceramic transducer 192 with the shield housing 195 which is used as the ground electrode a skin contact surface 197 is flat with rounded edges to avoid local overpressure on the patient 39 s body with a linear ridge 198 providing reliable acoustic contact with the tissue fig2 shows two orthogonal cross sections of another embodiment of a broadband ultrasonic transducer in accordance with the present invention frontal 200 and lateral 201 cross sectional views are represented.