| 摘要 |
A Doppler ultrasonic diagnostic apparatus for measuring or displaying the velocity information of moving members within an organism by transmitting and receiving ultrasonic waves is used for ultrasonic diagnosis in the medical field and the like. The apparatus is composed of a transmission circuitry for producing two ultrasonic waves having different repetition periods and outputting an ultrasonic wave after change-over between them; a velocity calculating means for calculating the velocities of moving reflective members on the basis of the received Doppler signals from the two ultrasonic waves, for example, a velocity calculator or an autocorrelator for obtaining the autocorrelation of a received signal after converting it to a complex signal; a memory for storing the velocity information signals obtained by the velocity calculating means; and other calculating means. The velocity of the moving reflective members is obtained by calculating the difference between or the sum of the two kinds of velocity signals, or calculating the conjugate product or the complex product of the two kinds of velocity signals. The present invention makes it easy to obtain accurate velocity information by an apparatus having a simple structure.
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