Multi-Gaussian Model for Estimating Stiffness Surrogate using Arterial Diameter Waveform

Abstract

Central Arteries’ elastic nature plays a fundamental role in maintaining cardiovascular health. Timely assessment of arterial stiffness helps in cardiovascular risk stratification. Various technological and methodological approaches exist to estimate arterial stiffness, through direct measurement of stiffness markers or surrogates. This work highlights a potential surrogate for arterial stiffness, based on the early onset of reflection waves. The significance comes with using low frame rate A-mode ultrasound scans for processing arterial diameter, modelled as a sum of three Gaussians. The novelty lies in the Gaussian modelled reflection onset time $\left( {\tau _R^{GM}} \right)$, derived using the model parameters, a potential surrogate for early reflections and arterial stiffness. An observational cross-sectional study group of 34 subjects were recruited to validate this hypothesis. A statistically significant (p < 0.0001) correlation was obtained for $\tau _R^{GM}$ against known stiffness markers. An R > 0.85 was obtained against Elastic modulus, specific stiffness index, and Pulse wave velocity. There exists an inverse correlation between the $\tau _R^{GM}$ and popular stiffness markers. A statistically significant (p < 0.0001) correlation was obtained for $\tau _R^{GM}$ against age, with R = 0.56. The early reflections were reliably detected by the $\tau _R^{GM}$ and the evidenced strong correlation with stiffness markers make it a potential surrogate for arterial stiffness assessment. The advantage being that it can be obtained from a single pulse waveform like diameter.