Figure 9: Pulsed Doppler recording of the aortic flow in a marmoset. Pulsed Doppler EC is also used to assess arterial flows. The Doppler window for aortic or pulmonary flows is placed just above (downstream of) the sigmoid valves. For either flow, a negative wave is recorded at each beat, from which V max , VTI, pre-ejection time, acceleration time (AT) and ejection time (ET) can be measured (Figure 9).