Надежность и качество сложных систем (Oct 2023)
MODEL OF THE ELASTIC SHELL IN THE ARTERY – CUFF SYSTEM
Abstract
Background. The occlusal cuff is widely used for non-invasive blood pressure measurement. The mechanical interaction between the artery, forearm tissue and cuff is a factor potentially affecting the accuracy of systolic and diastolic pressure measurements. Materials and methods. To quantify the intra-cuff stresses created by the compression cuff, it is necessary to conduct theoretical studies to determine the factors that have a significant impact on blood pressure estimates. In the work, it was proposed to use the stress and strain tensors in the form of three-dimensional vectors of normal and tangent components when building a model for changing the geometric dimensions of the elastic shell from pressure difference, which ensured the compactness and transparency of the representation of the derivation of basic equations. As a result of the study, it was shown that the simulated deformations are highly sensitive to the pressure distribution on the outer and inner surfaces of a cylindrical vessel. Moreover, vessel tissues experience volume compression, which causes deformation of the vessel shell in thickness and the formation of a stressed state of tissues in the absence of excessive pressure inside the vessel. Since for a thick-walled vessel, the areas of the inner and outer surfaces are different as a result of compression, a fixed displacement of the tissues occurs in the cuff, due to the difference in the total external forces. The model allows you to demonstrate the deformation of the vessel and the change in its geometric dimensions under the influence of external pressure applied to the body. Results and conclusions. The study shows that blood pressure measurements can be seriously influenced by the nonlinear properties of the elastic modulus of the arterial membrane in transmural interaction models based on the use of an occlusive cuff.
Keywords
