Bi-directional continuous wave doppler flowmeter and its application in investigations of disturbed blood flows

The paper deals with a new two-way DOPPIatli apparatus and with its clinical applications. A mathematical description is given of operations le¬ading to the separation of a signal in dependence of the flow direction. Also a block diagram of an analogue realization of such a system, and a diagram of a broad-band phase shifter, which is the principal part of the system, are presen¬ted. The part of the paper dealing wth the applications shortly presents diag¬nostic methods and new clinical applications of flowmeters, in. which the sys¬tem of separating flow directions plays a significant part.