Repeatability and Reproducibility of Flow Mediated Dilation Measured using ARTSENS

Abstract

Non-invasive assessment of endothelial function (EF) is clinically important to monitor early vascular aging and cardiovascular risks. Current devices are imaging ultrasound-based, using dedicated software packages for EF assessment via brachial flow-mediated dilation (FMD). Such devices often come as a workstation that are not field amenable. Additionally, the required special software packages are not featured in affordable entry-level devices. We have developed an image-free ultrasound technology for measuring arterial stiffness and demonstrated its field usability earlier. In this work, we have employed an evolved form of technology for fully automated measurement of FMD. An in-vivo study was conducted on 30 healthy subjects to investigate the repeatability and reproducibility of the measurements furnished by the device. The device was able to measure the continuous end-diastolic diameter values and capture its variations over the course of the complete FMD protocol. Cycle cutting algorithm screened the measurements from individual beats with a sensitivity and specificity 94%. The brachial diameter measurements during baseline (2.27 - 5.17 mm) and dilation phases (2.61 - 6.00 mm) concur with the ranges reported in the literature, and so does the FMD (4.67-38.32%). The intra- and inter-operator measurement demonstrated excellent repeatability ($ICC\gt 0.95$). Future studies in this regard include establishing the device’s accuracy against imaging reference, deeming it suitable for clinical and field deployment.