Dependence of biomechanical impedance upon living body structure

A physical model for biomechanical impedance has already been proposed. This model is characterised by three impedance spectra: soft, intermediate and hard pattern. An impedance spectrum of the body surface represents mostly the soft pattern, The formative mechanisms of all three patterns have been unsolved until now. Because the physical model is expressed by experimental equations, its theoretical background is not apparent. In the paper a simulating material (simulator) is used, whose tactility is not unlike human skin, and the formative mechanism of biomechanical impedance is revealed through experiments on the simulator under various measuring conditions. The influences of the measuring circumstances, living body structure and physical constants of the body tissues on the experimental equations of the physical model are fully discussed. The formative mechanism of biomechanical impedance which represents the physical model is explained in terms of an equivalent mass, a dynamic equivalent stiffness, a dynamic viscosity and a composite characteristic. The dependence between body parts from which the measurements are taken and soft, intermediate and hard patterns are demonstrated.