Human Red Blood Cell Properties and Sedimentation Rate: A Biomechanical Study

Human blood is widely used for clinical diagnostics due to its easy accessibility and high sensitivity for any metabolic disorders and diseases. In the paper different mechanical and electric properties of red blood cells (RBC) useful for diagnostics are discussed. The experimental data on the erythrocyte sedimentation rate (ESR) test in its standard procedure and continuous computer assisted assessment are presented. The review of mathematical approaches for reasonable ESR estimation is given. The continuous model of blood as three phase suspension is used for numerical estimation of aggregate ability of RBC. The problem on RBC aggregation and sedimentation in a thin vertical tube is considered. A numerical solution of the formulated hyperbolic problem is obtained by the method of characteristics. Numerical computations have been carried out for a wide range of RBC parameters proper to healthy state and patients with cancer, drug and food allergy. It is shown the continuous sedimentation curves give more diagnostic information than the standard ESR value. Based on the experimental and theoretical study, a biomechanical interpretation of the ESR curves is proposed.