Influence of Reflected Waves on PWV Estimation via Cross-Correlation in a Variable-Stiffness Arterial Surrogate: In Silico Simulation

Pulse Wave Velocity (PWV) measurement is of primary importance in clinical practice, as it significantly contributes to the early detection and treatment of cardiovascular diseases. This study investigates the reliability of the cross-correlation method for estimating PWV in a variable stiffness arterial surrogate considering the influence of reflected waves. In silico pressure waveforms were generated at two measurement sites based on mathematical models incorporating mechanical and geometrical characteristics of the surrogate. The waveforms were shifted in time by known delays to simulate various stiffness levels. Different levels of white Gaussian noise were also superimposed onto the signals. Results show that while the method performs reliably for E up to 3 MPa, it overestimates PWV at higher stiffness conditions due to increased overlap between forward and reflected waves. Measurement uncertainty also increases with increasing wave speed, highlighting the importance of accurately knowing the distance between the two measurement sites. Additive noise has less than a 2% impact on the mean PWV values but with increased data dispersion.