| 摘要 |
The disclosure is directed to a method and apparatus for determining the velocity of a material within a body, and which is also capable of simultaneously imaging sections of the body. In the velocity-determined method, a focused beam of ultrasound is directed, over a given aperture, toward the skin of the body, the central ray of the focused ultrasound beam being oriented substantially normal to the skin. The ultrasound beam reflected from the body is received over the same aperture. Preferably, the steps of directing and receiving the ultrasound employ the same single transducer, and focusing is achieved using a focusing lens. Beat frequency signals are detected in the received beam, these signals resulting from the beating of Doppler effect components reflected from the moving material, for example, blood corpuscles of moving blood within the body. Velocity-representative indications, for example, audio or video presentations, are then generated as a function of the detected beat frequency signals. The detected beat frequency signals are beats between Doppler effected portions of the received ultrasound beam which have frequency components above and below the frequency of the originally directed ultrasound beam. |
