Abstract: Method and apparatus for synthesizing a continuous estimate signal of a Gaussian signal resulting from ultrasonic Doppler measurement on a fluid flow, from existing segments of the Gaussian signal. The segment signals are first stored and there is at the same time calculated a characteristic frequency parameter for each segment. The frequency parameter is combined with the first stored segment signal for transposition thereof to a base-band at or about the zero frequency point, and this base-band signal is used to generate coefficients in a controlled filter device which on the basis of a broad-band input signal gives a synthesized filter output signal which is a substantially Gaussian signal. The filter output signal is multiplied by a weighting or window function for smoothing the transitions between successive segments.

Abstract: Method and apparatus for generating a multidimensional map of blood velocities in the circulatory system of living species, using the Doppler effect of backscattered ultrasound from the blood, with real time presentation on a display device, with the ability to select small sample volumes in the flow map where the information can be presented as a function of time together with the moving multidimensional map in real time. There is transmitted a pulsed ultrasonic beam which is swept in two or more dimensions through the region of the biological structure which is to be investigated. The backscattered ultrasonic signal is sampled in a number of depth volumes along each beam direction of the transmitted ultrasonic pulses. For each depth and beam direction there is determined a velocity parameter of the blood flow by means of the Doppler principle, and the velocity parameters from the whole region investigated are read into an image memory.

Abstract: Method and apparatus for ultrasonic blood flow velocity measurement based upon the doppler principle (doppler measurement), combined with simultaneous echo amplitude imaging by employing ultrasonic pulses (echo imaging). The method is used for investigation of living biological structures, in particular during movement, for example a heart function. The main application will be in hospitals and the like. The doppler measurement and the echo imaging is effected sequentially with so short intervals that the echo imaging is updated with a sufficiently high rate for obtaining an acceptable picture quality, with the doppler measurement occupying a substantial portion of the time. The information is presented in real time on a display screen. A control unit synchronizes the doppler measurement and the echo imaging, and there is incorporated one or more transducers in the equipment.