| 摘要 |
An ultrasonic pulse Doppler blood flow meter which has: a rate pulse generator for outputting a rate pulse, a pulser receiving the rate pulse for outputting a drive pulse, a transducer excited by the drive pulse for transmitting an ultrasonic wave into an object to be detected and receiving the echoes thereof for converting the echoes into an electrical signal, a range gate circuit for outputting a sampling pulse after a predetermined time from the output of the rate pulse, a sample and hold circuit for sampling and holding the echo signals from the transducer in accordance with the sampling pulse, a converter for Fourier-converting the sampled echo signals, and a monitor for indicating in a intensity the converted echo signals advantageously further comprising: shifting circuit for shifting said predetermined time between the rate pulse and the range gate pulse at the individual periods of the rate pulse, and a switch circuit for selectively connecting the rate pulse generator and the shifting circuit to the drive pulse generator.
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