| 摘要 |
PURPOSE:To enable a moving direction and a magnitude of a velocity vector to be measured correctly in an apparatus using a continuous ultrasonic wave by setting up two different receive openings and by receiving two reflection echoes in directions shifted with a specified angle from one another. CONSTITUTION:An ultrasonic beam is continuously emitted by a transmission oscillator 16 in a specified direction toward a specified position in a subject body, and its reflection wave is received by two receive openings of a receiving oscillator 18. In this case, a control of openings may be carried out either by increasing or decreasing the number of oscillator units or by changing the positions of oscillator units while keeping their number same. In the latter case, however, it is necessary to carry out a beam deflection control so as to shift the beam directions toward two openings. Reflection echoes from the same moving reflector in the subject body are thus received at different positions of receiving oscillator 18, and two different velocity informations in the two reflection directions, which is specified with a specified angle from one another, are obtained. Therefore, a moving direction and a magnitude of a velocity vector are correctly measured from these two informations. |
