Device for obtaining pulsed doppler effects using only a CW doppler system

摘要

The device consists of a large-diameter multi-ring transducer 1 equipped with an acoustic lens of adjustable focus 2. One of the transducer rings transmits a continuous wave and another ring receives a continuous wave, thus operating like a CW doppler system. For a large-diameter transducer, the focused zone 3 is very small, no more than a few mm3. The CW doppler system in reality examines only this focused zone and very little of the other zones 4. The adjustable focus acoustic lens enables a choice to be made of the zone to be examined. The result is thus similar to the pulsed doppler system. Intended particularly for use in medical applications of the doppler effect. IMAGE