New method for estimating arterial pulse wave velocity at single site

The clinical importance of measuring local pulse wave velocity (PWV), has encouraged researchers to develop several local methods to estimate it. In this work, we proposed a new method, the sum-of-squares method ∑PR2$\left( {\mathop \sum \nolimits_{PR}^{2} } \right)$, that allows the estimations of PWV by using simultaneous measurements of blood pressure (P) and arterial diameter (D) at single-location. Pulse waveforms generated by: (1) two-dimensional (2D) fluid-structure interaction simulation (FSI) in a compliant tube, (2) one-dimensional (1D) model of 55 larger human systemic arteries and (3) experimental data were used to validate the new formula and evaluate several classical methods. The performance of the proposed method was assessed by comparing its results to theoretical PWV calculated from the parameters of the model and/or to PWV estimated by several classical methods. It was found that values of PWV obtained by the developed method ∑PR2$\left( {\mathop \sum \nolimits_{PR}^{2} } \right)$ are in good agreement with theoretical ones and with those calculated by PA-loop and D2P-loop. The difference between the PWV calculated by ∑PR2$\left( {\mathop \sum \nolimits_{PR}^{2} } \right)$ and PA-loop does not exceed 1% when data from simulations are used, 3% when in vitro data are used and 5% when in vivo data are used. In addition, this study suggests that estimated PWV from arterial pressure and diameter waveforms provide correct values while methods that require flow rate (Q) and velocity (U) overestimate or underestimate PWV.