Abstract: The method and the device provides for the automatic processing of digitalized signals in order toremove speckle from the said signals by comparing the digitalized signal with a noise model obtained after learning its statistical properties,extract, from the signals, echos not characteristic of the contour of the organ to be displayed,extract the characteristic parameters of the contour from the said signals,calculate the contour from these parameters by likening them to a pre-established model of variable parameters,combine the digitalized signal, before or after eliminating noise, with the signal that is characteristic of the estimated position of the contour,display the resultant signal in which the contour appears as an overlay.

Abstract: Ultrasonic sensor and echograph with static sectorial scanning, especially for a wide angle picture, wherein according to a possible embodiment, the sensor comprises several groups of transducer elements forming between one another obtuse angles in such a way as to define overall a convex outline so that the delays or lags necessary to obtain a complete scanning be lower than with a conventional linear strip and thus easier to contol, the sensor being intended to be applied to medical echography.

Abstract: The present invention concerns a process for removing all ambiguity from the measurement by the Doppler effect of the speed of a target. It consists in obtaining a signal of Doppler shift relating to a series of ultrasonic pulses sent in the direction of the target and received after their reflection onto this target, the recurrence frequency of the pulses constituting an ambiguity limit of these speed measurements, wherein the measured Doppler shift is transposed by modulating the signal received by a signal at a frequency called determination frequency, so as to bring from a known value the spectral components to be analyzed in the useful measuring band and after measuring the true speed values are worked out by adjunction of a correction that depends upon the determination frequency that is used, this process being applicable to measuring the speed of blood in the medical field.

Abstract: An echography apparatus comprising a probe reconstituting mobile rings by element switching, said probe comprising a plurality of transducer elements spread over a convex coupling surface, and switching means being provided for grouping together certain transducer elements into rings.

Abstract: The invention relates to a method for characterizing the structure of a medium in which the ultrasonic absorption coefficient of the medium is measured. In order to perform a spectral analysis of this absorption, the spectrum of the signal reflected after it has been transmitted is evaluated by means of an autocorrelation method. Application: medical practice.

Abstract: The invention relates to a method of measuring the flow parameters of a fluid, and to a device utilizing this method, in which the autocorrelation function of the signal transmitted back by a particle of the fluid in motion is calculated. The mean speed and the variance of the flow are calculated by calculating the derivations of orders 1 and 2 of this autocorrelation function.

Abstract: A process of utilizing ultrasound for acquiring data representative of the internal portions of a structure and the display of the data thus obtained. This process includes the emitting of sequences of ultrasound to the structure under consideration and receiving therefrom corresponding echoes. For each sequence two groups of transducer elements are selected for generating ultrasound beams of possible N different focal characteristics sequentially. The ultrasound beams alternate from one group to the other except when a given beam corresponds to the most distant focal zone. In that case, the succeeding emission is carried out without alternating, i.e., the emission is generated from the same group.

Abstract: An ultrasonic probe for accurately determining angular location includes a rotating mobile assembly with at least one angular location track placed thereon. The angular location track is inscribed with location data arranged in a succession of pulses. As the mobile assembly rotates, the track traces a path in space. A fixed reading unit is provided at a point along the path to read the data inscribed on the track. The read data contains information corresponding to the angular position of the mobile assembly at any given point in time.

Abstract: The present invention relates to a linear voltage-pulse base-clipping circuit with adjustable-threshold condition.It comprises, for unipolar signals, two lines in parallel. The first line transmits the signal suitably delayed by means of an adjustable delay line to an attenuator which is controlled by the second control line which provides, depending on the threshold condition, the adjustment of the transfer of the attenuator.

Abstract: A probe primarily applicable to medical echography for achieving a variable compromise between depth of field and lateral resolution incorporates a main piezoelectric transducer, a plano-convex lens having an elastic diaphragm, an auxiliary transducer for measuring the deflection of the lens and means for controlling the deflection in dependence on a reference value by modifying the pressure exerted on the diaphragm by the fluid contained within the lens.

Abstract: An ultra-sonic echography apparatus comprises a probe with multiple elements switched at the rate of transmission pulses and moved along a contour of the test body. Its position is registered by a pantograph cooperating with three sine-cosine potentiometers, the sine potentials of which control the horizontal deflection plates of a cathode-ray tube, while the cosine potentials control the vertical deflection plates and a fourth potentiometer adds potentials displaced by 90.degree. with respect to those delivered by the said three potentiometers, so as to control the beam position of the cathode ray tube for obtaining, on the screen thereof, a beam trace which is homothetic with respect to the ultrasonic beam in the test body.

Abstract: Device for measuring the volume of sections of a tubular blank by ultrasonic echography. An ultrasonic pulse emitter -receiver is associated with an auxiliary reflector. The transducer and the auxiliary reflector are mounted on a rotary head. The blank moves forward continuously and the ultrasonic beam describes a helix on its surface. On basis of the measurement of the distances from the transducer to the outer and inner surfaces of the tube, a computer calculates the elementary areas and volumes and compares the sum of the elementary volumes with a reference value. The sections of constant weight are marked by a component controlled by the computer.