DEVICE FOR EXPLORING BY THE ULTRASONIC METHOD WITH A MOSAIC OF TRANSDUCERS PRODUCED IN AN ELECTROSTRICTIVE MATERIAL

摘要

An ultrasound examination apparatus comprises a processing circuit for echo signals from a mosaic of ultrasonic transducers which are made of an electrostrictive material with a non-remanent polarization. These signals are applied to processing channels which comprise coupling means (10i) for coupling the electrodes of the transducers to a circuit (20) for generating a polarization voltage ramp whose waveform is the inverse of that of the attenuation curve of the ultrasonic signals in the structures examined. These coupling means, for example, an RC circuit (11i, 12i) or a transformer (13i) enable the polarization voltage to be applied to the electrodes while inhibiting the transmission to the part of the processing channels which is situated behind the coupling means.