Synchronized measurements of maximum blood flow velocities in carotid, brachial and femoral arteries, and ECG in human posture changes

In this research, a system has been developed to measure the maximum blood flow velocity simultaneously by an ultrasonic Doppler technique in three arteries during posture changes. As a peculiarity of this system, two semicircular transducers of 15.0 mm in diameter were used as a transmitter to irradiate a wide ultrasonic beam and a receiver. Because, the position relation between an artery and transducers change rapidly during exercise. This system could be applied to a human body changing from a sitting position to an erect position with voluntary muscle constriction. As a result of measurements, the maximum blood flow velocity in femoral artery has been increased significantly in posture changes like the above.