| 摘要 |
PURPOSE:To enable display of a Doppler frequency pattern having no folded part in the case of carrying out Doppler analysis by decreasing a wrong measurement of the blood flow direction. CONSTITUTION:Transmission of a supersonic pulse is carried out at anisometric intervals of T and T+T0, and as for phase difference in pulses between wave transmission and wave reception, the wrong direction is corrected according to the fact that the phase difference of T+T0 becomes larger at all times than the phase difference of T. In the first and the second quadrants, 2pi is subtracted from the wrong phase difference, and in the third and the fourth quadrants, 2pi is added to the wrong phase difference, so that the correction can be carried out. |
