Doppler Microwave

A new Doppler microwave device designed for noninvasive arterial pulse detection by assessment of arterial wall motion was clinically evaluated. Carotid pulse tracings obtained with the microwave device were compared with simultaneously obtained intra-aortic pressure pulse waves. Ease and quality of the recording were also evaluated in 25 consecutive patients undergoing echocardiography. In 92% of the patients tested, good quality carotid pulse tracings could be obtained. T1/2 values and systolic time intervals were calculated from these recordings and correlated well with the known disease states of these patients, which ranged from aortic stenosis and aortic insufficiency to chronic heart failure. Finally, microwave tracings were faithful reproductions of invasive recordings of arterial pressures when compared on the basis of left ventricular ejection times and pulse contour.