Rheological properties of human blood in the network of non-equilibrium thermodynamic with internal variables by means of ultrasound wave perturbation

Abstract

Abstract This study is focused on the responses of whole blood and erythrocytes in saline solution when subjected to elastic stresses induced by ultrasound wave. Using a theoretical approach we obtained the expression of some thermodynamic functions depending on the complex wave number. This allows to the determination of very important rheological properties of the aforementioned materials and the explanation of how they react to frequency dependent ultrasound perturbation. We noted that the stress is greater in the solution of erythrocytes compared to whole blood but this difference is reduced as we approach to 108 Hz. These observations, in red blood cells solution might be due to lack of “oncotic protection” exerted by plasma proteins (albumin, ceruloplasmin) but when the frequency increases the same proteins precipitate because they lose their native folding resulting in the increase of whole blood viscosity. We could define 6.107 Hz as the threshold value beyond which in whole blood the ultrasonic waves cause the triggering of the phenomenon and the plasmatic proteins as a sort of “lubricant agents” that protect erythrocytes by the environmental perturbations. This work represents a preliminary part of wider results that we would like to achieve to the purpose of determining the threshold values of the macromolecular stability of a particular tissue as the human blood in response to dynamic stress.