Abstract: An apparatus and associated method are disclosed which form a multiple beam forming network using time division multiplexing. Instead of having several parallel sets of beam forming network hardware running at a given sampling clock rate, a simpler, single piece of hardware is run at a faster rate equal to the given sampling clock rate times the number of beams to be formed. Each sample received from each element is time division multiplexed into a bit stream, one for each beam. These time division multiplex element samples are weighted to apply the desired phase shift/time delay per element. Each weighted resultant is delayed in a cascade delay pipeline and then combined with the cascade combiner to form a beam at a given time division instant. This process is repeated for the next set of time division multiplexed samples and weights from each element of the array at a given time to form the next beam. The process is repeated for all beams until the sampling time interval ends.

Abstract: Doppler shifted reflection of ultrasonic energy are detected to measure and display the flow of particle-containing fluid, such as blood, through a body. The phase and magnitude of the autocorrelation function at a lag of one calculated from detecting and comparing the reflections from succeeding ultrasonic pulses are used as indication of the presence and velocity of fluid flow at each point in the body. The resulting data are stored and used as element of a graphic display of fluid flow.