AUTHOR=Bikia Vasiliki , Rovas Georgios , Pagoulatou Stamatia , Stergiopulos Nikolaos 

TITLE=Determination of Aortic Characteristic Impedance and Total Arterial Compliance From Regional Pulse Wave Velocities Using Machine Learning: An in-silico Study

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.649866

DOI=10.3389/fbioe.2021.649866

ISSN=2296-4185

ABSTRACT=<p><italic>In-vivo</italic> assessment of aortic characteristic impedance (Z<sub><italic>ao</italic></sub>) and total arterial compliance (C<sub><italic>T</italic></sub>) has been hampered by the need for either invasive or inconvenient and expensive methods to access simultaneous recordings of aortic pressure and flow, wall thickness, and cross-sectional area. In contrast, regional pulse wave velocity (PWV) measurements are non-invasive and clinically available. In this study, we present a non-invasive method for estimating Z<sub><italic>ao</italic></sub> and C<sub><italic>T</italic></sub> using cuff pressure, carotid-femoral PWV (cfPWV), and carotid-radial PWV (crPWV). Regression analysis is employed for both Z<sub><italic>ao</italic></sub> and C<sub><italic>T</italic></sub>. The regressors are trained and tested using a pool of virtual subjects (<italic>n</italic> = 3,818) generated from a previously validated <italic>in-silico</italic> model. Predictions achieved an accuracy of 7.40%, <italic>r</italic> = 0.90, and 6.26%, <italic>r</italic> = 0.95, for Z<sub><italic>ao</italic></sub>, and C<sub><italic>T</italic></sub>, respectively. The proposed approach constitutes a step forward to non-invasive screening of elastic vascular properties in humans by exploiting easily obtained measurements. This study could introduce a valuable tool for assessing arterial stiffness reducing the cost and the complexity of the required measuring techniques. Further clinical studies are required to validate the method <italic>in-vivo</italic>.</p>