Quantitative transcutaneous measurements of blood flow in carotid artery by means of pulse and continuous wave Doppler methods.

Abstract

<h2>Abstract</h2> The authors present results of quantitative measurements of blood <i>in vivo</i> in the carotid artery of man. The Doppler pulse technique was used after being previously verified for steady state flows in tubes and for pulsating flows in a canine aorta where the electromagnetic method was also used for comparison. An ultrasonic probe with two transducers was adapted for determination of the angle of the ultrasonic beam in relation to the vessel allowing the measurement of the vessel diameter which was also determined by means of the ultrasonographic <i>B</i>-mode technique. By means of the Doppler pulse method profiles of the blood velocity in the carotid artery were determined as a function of time. The continous wave Doppler technique together with the zero-crossing system and spectral analysis were also used for making measurements. The flow velocity and the shape of the flow curve with time obtained with the above techniques showed good agreement. The measured flow rate in the carotid artery amounted to <i>Q</i>_M = 1.61/min (maximum instantaneous value) and <i>Q</i>₀ - 0.531/min (mean time value).