Ultrasonic diagnosis apparatus for measurement of speed of moving medium in a living body

An ultrasonic diagnosis apparatus comprises an ultrasonic probe for transmitting an ultrasonic pulse beam toward an internal moving medium of a living body at a constant recurrence frequency, a converter for mixing the received high-frequency signal with a set of complex reference signals having a frequency n times as high as the recurrence frequency of the transmitted ultrasonic pulse beam and having a complex relation therebetween, thereby converting the high-frequency signal into complex signals, a speed operating circuit for computing the moving speed of the internal moving medium on the basis of the complex signals, and a display unit for displaying the moving speed in real time. The apparatus may include a speed dispersion operating circuit for computing the dispersion of the moving speed computed by the speed operating circuit in order to display both the moving speed and the dispersion thereof on the display unit.