Interpretation of Experimental Data is Substantial for Constitutive Characterization of Arterial Tissue

Abstract

The paper aims at evaluation of mechanical tests of soft tissues and creation of their representative stress-strain responses and respective constitutive models. Interpretation of sets of experimental results depends highly on the approach to the data analysis. Their common representation through mean and standard deviation may be misleading and give non-realistic results. In the paper, raw data of 7 studies consisting of 11 experimental data sets (concerning carotid wall and atheroma tissues) are re-analysed to show the importance of their rigorous analysis. The sets of individual uniaxial stress-strain curves are evaluated using three different protocols: stress-based, stretch-based and constant-based, and the population-representative response is created by their mean or median values. Except for nearly linear responses, there are substantial differences between the resulting curves, being mostly the highest for constant-based evaluation. But also the stretch-based evaluation may change the character of the response significantly. Finally, medians of the stress-based responses are recommended as the most rigorous approach for arterial and other soft tissues with significant strain stiffening.

Impact of Different Disinfection Solutions on Mechanical Properties of Orthodontic Impress Silicone Material

“…To compare the difference between the four groups (3 disinfectants and 1 control group), thirteen datasets were created by interpolating the strain value of stress-strain curves at thirteen stress-levels (Lisický et al, 2021), ranging from 0.1 MPa up to 1.3 MPa and sorted into four groups by the disinfectant used. At each stress level a one-way ANOVA test was conducted to determine whether there is a significant difference between the various disinfectant groups and the reference group.…”

Anisotropy of soft biological tissues and its consideration in constitutive models of arteries

“…4 illustrates the difference between mean and median values of stress-strain curves of human carotid arteries. Here the asymmetric distributions of strains calculated for the chosen stress levels show evidently a large dispersion and should be represented as mean and interquartile range (Lisický et al 2021b).…”

A fluid-structure interaction model accounting arterial vessels as a key part of the blood-flow engine for the analysis of cardiovascular diseases

“…Various mechanical properties of arteries have been studied from different aspects since Fung (Fung 2013). Biomechanical parameters of intact or separated arterial tissues (intima, media and adventitia) such as arterial stiffness, compliance, microstructure of elastic and collagen fibers, smooth muscle cells located within the artery wall, have been identified using methods such as planar or inflation tests to serve as a reference for clinical cardiovascular disease (CVD) diagnosis, treatment and monitoring (Niestrawska et al, 2016;Hoffman et al, 2017;Amabili et al, 2019;Ramachandra and Humphrey 2019;Lisický et al, 2021a). Also, constitutive models with different levels of complexity and number of parameters also have been developed, such as phenomenological extensions of Fung's model (Fung et al, 1979) and structure-based versions of the GOH (Gasser-Ogden-Holzhapfel) model (Gasser et al, 2006;Rachev and Shazly 2019;Lisický et al, 2021b;Holzapfel et al, 2021), to describe and predict the mechanical behaviors of arterial tissues.…”