Russian Journal of Biomechanics

A complex statistical (correlation, discriminant, factorial) analysis of a set of parameters - biomechanical characteristics of the corneoscleral shell of the eye, hemodynamic parameters and perimetric indices, determined during examination of 110 eyes, including 69 eyes with various stages of primary open-angle glaucoma (POAG) and 41 eyes without ophthalmopathology - was carried out. Significantly correlated parameters characteristic of a particular stage of POAG were identified. The set of identified correlations characterizes progressive glaucoma damage as a process associated with a simultaneous change in the biomechanics of the eye shells and the scleral lamina cribrosa, as well as the blood supply to the choroid and retina, which, apparently, underlies the gradual deterioration of its photosensitivity and changes in the visual field. It was found that correlations within groups of patients with various stages of POAG change significantly with the progression of glaucomatous process, and, possibly, reflect the change in the contribution of biomechanical and hemodynamical disorders to the development of glaucomatous lesion at the corresponding stage of its development.

Pain in the lumbar spine is a disease that affects a significant part of society and has an important impact on the life quality and working capacity of the world's population. The fight against this disease takes a lot of money from most of the developed countries of the world. Osteoporosis, herniated disc, kidney disease in most cases are the first cause of low back pain and this is not the whole list. It is well known that the intervertebral disc L4-L5 is a weak link in the lumbar region, so the need and relevance of the modelling problem of the lumbar vertebromotor segment already exists. A comprehensive analysis of studies for the period from 2003 to 2019 years was performed. The work purpose is to analyze most of the existing approaches to modelling the lumbar vertebromotor segment, the advantages and disadvantages of models and possible options for processing the segment geometric shape. The study focuses on such parameters as the influence of age and gender on the model, the choice of computed tomography or magnetic resonance imaging data, options for model validation, the constitutive relations choice, and the geometric shape of all parts of the model. Each of the parts of the lumbar vertebromotor segment is presented: the vertebra, the pulpous nucleus, the fibrous ring, the cartilage endplate and bone endplate, the facet joint and seven types of ligaments.

The most common causes of conducting a hip revision surgery after total hip replacement are aseptic loosening (aseptic instability) of the endoprosthesis, bone destruction as a result of contact with the endoprosthesis, and a periprosthetic fracture. These are the effects of load transfer to the bone tissue in arthroplasty resulting due to the difference in stiffness of the endoprosthesis and the bone. Titanium alloy is widely used in endoprostheses manufacturing because of its high biocompatibility, good wear properties, and corrosion resistance, but such endoprostheses are stiffer than the femur. These problems have aroused interest in searching for the best materials and topology for a femoral implant. Nowadays, additive technology is of great interest as it enables to create materials with graded density. These materials consist of multiple lattice structures with variable parameters and topology. By varying the parameters of lattice structures, one can adjust the mechanical properties of the material as required. These materials find their application in hip endoprostheses manufacturing, allowing adjust the parameters of the lattice structures and deliver a product with femur-like mechanical properties. The porous structure also ensures bone tissue ingrowth into the prosthesis. The authors designed and simulated an endoprosthesis made of graded density lattice structures with femur-like mechanical properties. Using numerical simulation software ANSYS Mechanical, authors determined the effect of the topology on the structural behavior of the femur and defined the endoprosthesis-femur combined performance under various load cases.

Feature of the course of the disease caused by coronavirus is the development of severe non-specific pneumonia, which disrupts gas exchange in the respiratory system and causes hypoxia. To save the life of patients in the critical stage of non-specific pneumonia, it is necessary to eliminate hypoxia. For this purpose, forced mechanical ventilation of the lungs using breathing gases enriched with oxygen is widely used. However, increasing the pressure, volume, and concentration of oxygen gas in the inhaled air does not always eliminate hypoxia in patients with COVID -19. The fact is that in this disease, the cause of the suffocation symptom is thick mucus and pus that fill the lumen of the bronchi. It is the mucus and pus that clog the bronchi that do not allow restoring airiness of the lungs, gas exchange and blood oxygenation in non-specific pneumonia. In this regard, it is the obstruction of the bronchi caused by mucus and pus that causes the critical stage of the disease in non-specific pneumonia caused by coronavirus. In these conditions, due to the lack of mucolytic aerosol for inhalation that would effectively dissolve thick mucus and thick pus, there is nothing left to save the patient's life but to eliminate hypoxia using extracorporeal membrane oxygenation. However, extracorporeal membrane oxygenation is a very expensive and very dangerous method of treatment, which itself causes the death of almost half of patients. In this regard, to increase the effectiveness of forced lung ventilation, it is proposed to use a special aerosol that, when inhaled, can quickly dissolve mucus and pus in the bronchi and remove them outside. The formulation of such an aerosol is given and an example of its effectiveness in obstructive bronchitis is described.