| 摘要 |
PURPOSE:To derive an exact tissue displacement by avoiding turn-back, in the tissue displacement measurement to which an ultrasonic pulse Doppler method is applied. CONSTITUTION:A turn-back detecting circuit 34 monitors a displacement signal outputted from a displacement arithmetic circuit 32, and outputs a detecting signal 200, when a displacement difference in a transmission repeat period exceeds a prescribed decision value. By this detecting signal 200, a transmission repeat frequency generating circuit 14 raises stepwise a transmission repeat frequency generated therein. In such a way, an effective displacement measuring range of the displacement arithmetic circuit 32 is enlarged stepwise, and turn- back is avoided. |
