One of the parameters determining the efficiency of cleaning the blood in hemodialysis therapy is an effective mass transfer processes of metabolites through the dialyzer, which is defined by the mechanism of molecular diffusion and convection of low and medium weight substances in the blood. The article presents an analysis of modern mass transport models: streaming and kinetic; the analytical expressions of the spatial and temporal distribution of metabolites in the dialyzer. The results of mathematical modeling showed that these models do not reflect the full extent of the entire mechanism of mass transfer and must be supplemented. This is primarily due to the fact that blood is a non-Newtonian fluid. In addition, during hemodialysis, there is a change of the rheological properties of the blood - viscosity aggregated and deformability of erythrocytes, which ultimately affects the dialyzer mass transfer processes, reduces its clearance and thus reduces the efficiency of hemodialysis. The authors consider that the solution to this problem might be to develop a space-time mathematical model of mass transfer (the so-called distributed model of mass transfer), built with the influence of the driving forces behind the transfer of substances through the membrane dialyzer basic parameters and characteristics of fibers and rheological blood properties. In our view, the space-time dependence of the distribution of concentrations of metabolites in the blood and dialysate hemodialyzers allow to predict normalization the concentration of metabolites in the blood, and thus improve the accuracy of assessing the quality of dialysis.

Keywords: hemodialysis, mathematical modeling, spatial distribution, the time dependence, the space-time model

Hemodialysis is a complex process requiring the increased control of some parameters, such as dialysis dose, blood perfusion rate, ultrafiltration, blood volume, its composition and etc. To solve the problem of control the blood during dialysis was designed the monitoring system of air inclusions - air bubbles. A very important part of this system is the ultrasonic air detector. It is set to venous blood highway - at the exit of blood from the dialyzer, and determines the presence in the cleaned blood any air inclusions by measuring the velocity of ultrasound in the analyzed multiphase medium - the blood, thus informing the doctor about the quality and security of hemodialysis procedure.

Keywords: Air embolism, bubble trap, air detector, speed of ultrasonic vibrations, the pulse-frequency method of measurement the ultrasonic speed.

The system that provides suppression external to the object magnetic disturbances during magnetoencephalography was developed. Register magnetic fields of the brain can detect features of the functioning of the CNS and to determine normal or pathological activity in human regulation systems, reflecting the functional state of human health. The designed system consists of a device for registration of external magnetic fields - fluxgate magnetometer, compensation module external magnetic field - coils Helmholtz, device register magnetic fields of the brain and compensate for a homogeneously magnetic field generated by the device of compensation of external magnetic fields.

Keywords: Magnetoencephalography, fluxgate magnetometer, coils Helmholtz, induction magnetometer