Further experimental evidence of the compressibility of arteries.

Further experimental evidence on the compressibility of arteries under normal physiological pressure range is provided using the experimental apparatus introduced in Yosibash et al., JMBBM 39(2014):339-354. We enlarged the experimental database by including almost twice the number of experiments, we considered a different artery - the porcine common carotid that allowed longer and larger diameters. In the physiological pressure range of 50-200mmHg, a relative volume change of 5% was obtained, lower compared to the sapheneous and femoral arteries (2-6%). Most of the arteries had a relative volume change of 1.5%. The relative volume change is found to be almost linearly proportional to the pressure, and inversely proportional to the dimensions of the experimented arteries (especially the artery length). The smaller the artery tested, the larger the relative volume change (such a phenomenon was also realized in Yosibash et al., JMBBM 39(2014):339-354.). We realized in recent past publications a flaw in the experimental protocol that results in an overestimation of the relative volume change (thus underestimating the bulk modulus). It is due to the consideration of experimental observations close to the zero pressure. Nontheless, in view of the experimental evidence, the pre-assumption of incompressibility in many phenomenological constitutive models of artery walls should be re-evaluated.