Том 51, № 4 (2017)

The present study focuses on the development of methods for design calculation and optimization of the circulatory support pump flowpath. The object of this study is the flowpath of an axial flow pump consisting of a straightener, an impeller, and a diffuser. The working fluid has constant density and viscosity that are close to the physiological parameters of blood of a healthy human. The fluid is considered to be incompressible; the flow is considered steady. Red blood cells in the stream are simulated with non-interacting spherical particles whose trajectories are considered as the trajectories of movement of red blood cells. Equivalent shear stress is calculated at each point of the particle trajectory. The damage parameter is calculated based on the current level of the equivalent shear stress and the time of exposure to shear stress. The criteria of maximum efficiency and minimal hemolysis are used as the optimization criteria. The flowpath is optimized according to these two criteria and local optimum parameters for the suggested initial geometry are determined.

Experimental in vitro studies have demonstrated the possibility of use and the efficiency of the hepatocyte suspension as a biological material for the elimination of toxic compounds and normalization of metabolic processes during plasma dialysis using a bioartificial liver device. The developed circuits and bioreactor devices provide optimal conditions for normal functioning of the rat hepatocyte suspension for several hours required for cell dialysis.

The variety of modern thermal flow velocity sensors and their technical specifications are considered. Advanced developments in the field of thermal flow velocity sensors are described. Possibilities of biomedical application of thermal sensors for monitoring blood flow are discussed.

A mathematical model of process optimization based on adaptive fuzzy Markov chain algorithms is presented. The model is shown to be effective in optimizing storage devices for platelet-containing transfusion media. The problem of maintaining the technological process state near the extremum of the objective function with the steady state-probability of ~90 % is solved.

One of the most promising methods for biomedical coating formation is based on the use of vacuum arc plasma sources that allow pure metals to be obtained and plasma-chemical synthesis of complex compounds to be carried out. In this work, the results of synthesis of titanium nitride and titanium carbide on metal substrates using specially developed equipment are presented.

We present here an analysis of the friction components in friction pairs of hip joint endoprostheses in conditions of dry friction and biological media. The tribological pairs studied were found to have different behavioral characteristics depending on the external loading and the “hardness” of the kinematic unit itself. The lowest levels of the adhesion component of the coefficient of friction were seen in ceramic−ceramic friction pairs.

Construction of a system for conducting thermal cosmetic procedures in which the operating unit is a thermoelectric energy transducer is discussed. We present the results of experimental studies of a research prototype. Practical tests demonstrated the applicability of the system in practice and showed that standard thermoelectric modules produced by Russian firms can be used, with short warm-up periods and low inertia on changing thermal operating modes.

A fuzzy biotechnical operator productivity control system with feedback based on the leading type of perception of information and the emotions is presented. The system is noninvasive and can be used all day to monitor a human operator’s state of fatigue, drowsiness, etc. Factors affecting operator productivity are described briefly, along with the components of productivity, diagnostic challenges, monitoring of psychoemotional status, and the results of the diagnosis of these states from changes in the manipulation of pointing devices; the resulting system is described, along with regression and fuzzy approaches to diagnosing productivity.

A virtual instrument for analysis of event-related potentials based on LabVIEW is described. Without specific apparatus, this allows the components of event-related potentials to be resolved, with automatic measurement of amplitude, frequency spectrum, power, mean square values, and differences between maximum and minimum amplitudes. The virtual instrument may be useful for developing telemetry systems for functional diagnosis with automatic processing of large volumes of data using the event-related potentials method.