Abstract: A device for scanning objects, notably biological tissues, by means of ultrasound echography, which device includes at least one ultrasound transducer (10) which is connected to a transmitter stage (20) for the repeated transmission of ultrasound waves to the object to be examined, and to a receiver stage for receiving the echoes reflected in the direction of the transducer. The device in accordance with the invention is characterized mainly in that the receiver stage includes:(A) a transformation device (110) for transforming the echographic signal by calculation of the Mellin transform of this signal;(B) an arithmetic device (120) for calculating a correction function by transformation of the attenuation function;(C) a processing device (130) which consists of a series connection of a multiplier circuit (131) for multiplying the respective output signals of the transformation devices (110) and (120) and a circuit (132) for calculating the inverse Mellin transform of the signal thus obtained.

Abstract: The device comprises at least one ultrasound transducer (10) which is connected to a transmitter stage (20) and to a stage (30) for receiving and processing echographic signals returned to the transducer. The latter stage (30) comprises a conventional first processing channel (60) which consists mainly of an amplifier circuit (61), an envelope detection circuit (62), a scan converter (64), and a display device (65), as well as a second processing channel (100), which comprises:(A) an analog-to-digital converter (63) and a first image memory (641) for storing the image during acquisition;(B) a motion detection circuit (130) which controls, or not, for each image point the application of a recursive temporal filtering coefficient .alpha.

Abstract: A device for the scanning of media by means of ultrasound echography, comprising at least one ultrasonic transducer (10) which is associated with a transmitter stage (50) and with a receiver-stage which comprises a conventional first processing circuit (101, 102, 103) and a second processing circuit which is connected parallel thereto and which comprises a series connection of a circuit (210) for automatic gain control as a function of the distance of the echos, a heterodyne circuit (230), and n parallel channels, each of which comprises a series connection of a circuit for the correction of diffraction effects, a filter (240a . . . 240n) for selecting a narrow frequency band from the pass-band of the transducer, a logarithmic amplifier (250a . . . 250n) and a divider (260a . . . 260n) whose output is connected to one of the n inputs of a circuit (270) for determining values whose output is connected to the display device provided in the first processing circuit.