Blood flow in arteries determined transcutaneously by an ultrasonic doppler velocitymeter as compared to electromagnetic measurements on the exposed vessels

We have compared the instantaneous mean blood velocity measured transcutaneously from total cross-sections of arteries in dogs by the use of a new pulsed heterodyne ultrasound doppler equipment, with instantaneous blood flow as measured simultaneously by an electromagnetic flowmeter applied on the exposed vessels. The experiments were performed on the common carotid and the femoral arteries in a variety of flow situations, always with a close fit between the two curves. The results show that the output from the ultrasound equipment is proportional to flow.