Extended Data Fig. 5: Pulse wave velocity (PWV) measurements.
From: A fully integrated wearable ultrasound system to monitor deep tissues in moving subjects
a, Schematic illustration of the pulse wave propagation paths in this study. Five paths were investigated, including the heart to the abdominal aorta (H-Ao), the heart to the carotid artery (H-CA), the heart to the femoral artery (H-FA), the heart to the brachial artery (H-BA), and the brachial artery to the radial artery (BA-RA). b, Pulse waveforms collected by synchronized USoP pairs. The pulse transit time (PTT) was defined as the delay between the diastolic feet of the ventricular contraction and arterial pulses. c, The average PTT values by the USoP and the tonometer, showing consistency for both H-BA and BA-RA. Ten consecutive pulses were recorded to calculate average PTT values. The error bars represent the measurement standard deviations. d, PWV calculated across five arterial segments using the USoP. e, PWV mapping under normal conditions and cold pressor test. The average PWV along each path was calculated from five independent measurements. The error bars indicate the standard deviations of the measured values. The PWV increases from heart-proximal to heart-distal branches. There is a regional increase of PWV in H-BA and BA-RA segments owing to cold-induced vasoconstriction.
