Batsak B. Physical mechanisms of interaction of pulse wave with obstacles and formation of arterial pressure

The dissertation is devoted to research of interaction of pulse wave with obstacles and mechanisms formation of arterial pressure. In work the analysis of existing models of blood flow and formation of pulse waves is carried out. A model of blood vessel in which the arterial vessel is considered as a waveguide is proposed. Experimental studies of blood flow were performed using the methods of magnetic resonance imaging and ultrasound diagnostics. It is proved that the dependence of blood velocity on the change of the cross-section of the vessel is linear. Mechanisms of interaction of a pulse wave with obstacles and formation of arterial pressure are suggested, according to which in the main artery as a waveguide the interaction of a primary pulse wave with an obstacle can be described by two types of harmonic waves: inhomogeneous and homogeneous. Strong attenuation of inhomogeneous and small amplitude of homogeneous reflected waves virtually eliminates the possibility of multiple reflections, thus minimizing the influence of reflected waves on blood movement. Based on this mechanism of blood pressure formation, a new approach to pulse blood pressure measurement has been proposed. A non-invasive method for measuring local pulse blood pressure and a non-invasive method for determining the local elasticity of vascular walls, which allows to evaluate the condition of vessels in pathological processes, has been developed. These methods can be applied in clinical practice, in particular in cardiology and cardiac surgery.