| 摘要 |
PURPOSE:To prevent a reflected phenomenon at the ultrasonic Doppler diagnostic device and calculate blood circulating speed or the like while excluding the motion of a biologicol tissue. CONSTITUTION:The inverse tangent is operated concerning an orthogonally detected signal, and a phase angle DELTAphi corresponding to a Doppler deviation frequency is calculated by a phase difference arithmetic circuit 28. then, a coordinate system rotary orthogonal component arithmetic circuit 34 operates the orthogonal components of velocity signals after rotating a coordinate system just for a and after the respective components are averaged, the inverse tangent is calculated. Thus, an averaged phase angle DELTAphi' is calculated. On the other hand, a biological tissue motion detection circuit 46 detects the tissue motion and the value of alpha is dynamically varied. |
