Abstract: An ultrasonic diagnostic system and scanning technique are described for producing three dimensional ultrasonic image displays utilizing power Doppler signal information. In a preferred embodiment the power Doppler signal information is displayed in the absence of structural (B mode) information to reduce image clutter and provide three dimensional image segmentation. An ultrasonic scanning technique is presented for acquiring diagnostic three dimensional ultrasonic images of power Doppler intensity through manual hand scanning of a patient, without the need for specially fabricated scanning mechanisms or devices.

Abstract: An echo ultrasound imaging system comprising at least one array of elementary transducers, and further comprising an emission stage and a stage for the reception and for the processing of echoes reflected back towards the said array, said reception and processing stage having means for the simultaneous focusing of M ultrasonic beams originating from M different directions; the emission stage has means for the focusing of M ultrasonic beams emitted sequentially in the said M different directions, and during a total duration defined by the sum of the M maximum delays of the M delay laws forming the said M focused beams emitted.

Abstract: A device for eliminating fixed echoes for an ultrasonic echograph, comprising a first filter (100) which consists on the one hand of M parallel lines i (i=1, . . . , M) which a respective delay (i-1)T, where T is the repetition period of the echograph, and on the other hand of weighting means (101i) for the M lines i, the sum of the coefficients (a.sub.i) applied to said lines being zero and, of an adder (102) for the lines i thus delayed and weighted. In accordance with the invention, at least one second filter (200) which has the same structure as and which is dephased by (M-1)T with respect to the first filter (100) is connected parallel to the first filter (100), the pulse response (h.sub.2 (t)) of the second filter being linked to the pulse response (h.sub.1 (t)) of the first filter as:h.sub.2 (t)=h.sub.1 (m-1)T-t).Application: Measurement and imaging of blood flow speeds by ultrasonic echography.

Abstract: An apparatus for examining a moving object by means of ultrasound echography, enabling the measurement of the axial speed of said movement or the projection of the speed on the axis z of a beam of ultrasound excitations transmitted by an ultrasound transducer (10) with a repetition period T. The apparatus also comprises a transmission stage (20) and a stage (30) for receiving and processing the echographic signals returned to the transducer (10). The stage (30) for receiving and processing the echographic signals comprises a circuit (330) for estimating said axial speed V.sub.Iz (t) which comprises a circuit (340) for extracting the time shift .tau..sub.i (t) between two consecutive echoes e.sub.i (t) and e.sub.i+1 (t), constructed for solving the equation in .tau..sub.i (t): ##EQU1## where e.sub.i (t) is the derivative of the order "n" with respect to the time of the echo e.sub.i (t), and a circuit (350) for multiplication by C/2T so as to obtain V.sub.iz (t) on the basis of .tau..sub.

Abstract: An apparatus for scanning moving objects, notably flowing blood, by means of ultrasound echography in order to determine movement parameters of such objects. The apparatus comprises at least one ultrasound transducer which is connected to a stage for the periodic transmission of a pulse signal having a predetermined recurrent frequency F=1/T and to a stage for receiving echograpic signals returned to the transducer and for processing the signals received. In accordance with the invention, the apparatus is characterized in that it comprises a digital processing channel which is successively composed of a circit (320) for suppressing fixed echoes, a circuit for estimating flow parameters, a discriminator circuit (360), a device (370) for storage, scan conversion and color encoding, and a display device (312).

Abstract: An apparatus for the examination of objects with ultrasound, comprising a linear or two-dimensional array (10) of piezo-electric transducer elements (10 (1), . . . , 10 (n)) with a length L and a width W, a stage for the repeated transmission of ultrasonic signals and a stage for the reception and processing of the ultrasonic echoes received. The thickness T of the elements is equal to half the wavelength corresponding to a first frequency F for which there exists, on the two-dimensional diagram of the curves F.multidot.T=f(W/T), or respectively, on the three-dimensional diagram of the curves F.multidot.T=f(W/T, L/T) of the distribution of the resonance frequencies, a first vibratory mode at the said first frequency F and a second vibratory mode at a second frequency equal to or near 2F. The transmission stage incorporates a generator (20) of excitation signals at the first frequency F, the spectrum of these excitation signals excluding at least the second frequency.