| 摘要 |
PURPOSE:To detect Doppler shift in the optimum state with respect to a plurality of probes having different inherent frequencies, by automatically selecting the oscillator corresponding to the inherent frequency of the probe to be used and making the ultrasonic transmission pulse supplied to the probe synchronous to the output signal of the oscillator. CONSTITUTION:A frequency selector 23 supplies a frequency divider 4 with the output signals of oscillators 22a, 22b, or 22c corresponding to the inherent frequency of a probe 10; while a synchronous circuit 25 makes the output signal from the frequency divider 4 perfectly synchronous to the output signal from the selector 23 to supply the same to a control circuit 8 which is turn generates an ultrasonic transmission pulse in synchronous relation to said signal to supply the same to the probe 10. The ultrasonic wave reflected from an examinee is converted to an echo signal to be supplied to the circuit 8 and an ultrasonic tomographic image is displayed on a display apparatus 11. At the same time, the echo signal is supplied to a Doppler control circuit 24 and synchronous detection is performed on the basis of the signal from the selector 23 to extract Doppler shift and frequency analysis is performed to form a blood flow analytical data which is, in turn, displayed on the display apparatus 11. |
