This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. 1 Analysis of Viscoelastic Wall Properties in Ovine Arteries

Abstract—In this study we analyzed how elastic and viscoelastic properties differ across 7 locations along the large arteries in 11 sheep. We employed a 2 parameter elastic model and a 4 parameter Kelvin viscoelastic model to analyze experimental measurements of vessel diameter and blood pressure obtained in-vitro at conditions mim-icking the in-vivo dynamics. Elastic and viscoelastic wall-properties were assessed via solutions to the associated inverse problem. We used sensitivity analysis to rank the model parameters from the most to the least sensitive, as well as to compute standard errors and confidence intervals. Results revealed that elastic properties in both models (including Young’s modulus and the viscoelastic relaxation parameters) varied across locations (smaller arteries were stiffer than larger arteries). We also showed that for all locations, the inclusion of viscoelastic behavior is important to capture pressure-area dynamics. I