Abstract Body: Background :
The arterial pulse wave velocity (PWV) is a strong marker of cardiovascular risk and hypertension. The development of devices enabling a robust and reliable assessment of PWV could play an important role in the early diagnosis and monitoring of those diseases. In this work, we propose an ultrasound technique to estimate blood flow volume (BFV) and PWV by simultaneously using two probes.
Methods:
Two linear arrays, held by a handle, image two cross-sections of the artery, on two planes intersecting at 40° at the vessel center (A). B-mode and color flow Doppler (CFD) images are reconstructed at high frame rate (HFR): the cross-section HFR CFDs, providing vector-Doppler imaging, avoid any assumptions on flow velocity direction and profile, thus enabling reliable BFV estimates; the HFR B-mode allows tracking the arterial wall, thus enabling robust and time-resolved estimates of the lumen area (B). PWV is estimated as the ratio between the change in flow and cross-sectional area during the early systole (C).
The method was preliminary verified by repeating 12 times the BFV and PWV estimation on the carotid artery of 8 healthy volunteers.
Results:
PWV and BFV measures were in the physiological range of 4.0-6.6 m/s (D) and 4.2-10.8 cm³/s, respectively. Measures were repeatable as proved by narrow interquartile ranges and low average standard deviations (1.4 m/s and 1.1 cm³/s, for PWV and BFV), which confirm the method's robustness.
Conclusions:
The proposed technique is suitable for BFV and PWV estimations. Since it is robust to probe repositioning and does not rely on any assumption of flow direction and profile, it could be implemented on wearable cardio-vascular wellness monitoring devices.