A Doppler ultrasonic flowmeter and an impedance cardiograph were used for measurements in 30 patients with various arterial disorders. In five cases, the devices proved to have a determinant influence on clinical management by supplying data not otherwise obtainable at the bedside. Of the two instruments, the Doppler flowmeter proved to be more sensitive and more easily used, although only the impedance cardiograph has the potential for supplying information on total flow. The latter device lacks sensitivity in low flow states (less than 10 ml/min), but this can perhaps be overcome by using a venous occlusion method.
Couch NP, Van De Water JM, Dmochowski JR. Noninvasive Measurement of Peripheral Arterial FlowImpedance Cardiograph and Ultrasonic Doppler Flowmeter. Arch Surg. 1971;102(5):435-439. doi:10.1001/archsurg.1971.01350050001001