Vol 50, No 3 (2016)

This article describes the design of a nonpulsating total artificial heart (TAH), presents the basic preconditions for the creation of a nonpulsating artificial heart, describes the design solutions in the design of the TAH, and provides the basic characteristics and stages of TAH development projects in the world.

This article reviews the problem of centering the rotor of an axial pump of the artificial heart ventricle (AHV) in a magnetic suspension. The small gap of the flowing part, high rotor speed, necessary service life of the AHV device, and its reliability and functionality introduce high demands on the control system of the rotor with magnetic bearings. This article proposes a synthesis of the control laws of the AHV with magnetic bearings based on the ADAR method (analytical design of aggregated regulators) of synergetic control theory and presents possibilities and prospects of applying the proposed control scheme.

One of the objectives of population screening programs is to control and prevent heart disease. This particular problem is solved within the framework of the project CardioQVARK. Among the most important functions of the ECG monitoring equipment is identification of atrial fibrillation (AF), which refers to the most common and dangerous arrhythmias. Today, there are many algorithms to identify this disorder, but the accuracy of the best algorithms does not exceed 94.5%. In this paper, we propose an algorithm based on graphical representation of regularities in the order and length of RR-intervals (distances between adjacent R-waves of the ECG) and consider method for its implementation.

The use of artificial neural networks for detection of ECG signal distortions was discussed. Training and test databases were compiled. A technique for analysis of training samples based on the k-means clustering method was suggested. The effect of the number of hidden layer neurons on the neural network efficiency was studied. A method for testing the neural network efficiency based on the receiver operating characteristic (ROC) curve was developed. The structural principle of the neural network detector of ECG signal distortions was also developed. Testing of the system demonstrated high values of sensitivity and specificity (94.5%), as well as a high mean value of AUC (0.97).

The impact of electrode size on transthoracic impedance and the dose-dependent efficacy of electrical cardioversion for elimination of atrial fibrillation persisting up to 48 hours in patients with ischemic heart disease was tested.

The Diamant-AIST device (Diamant Ltd., St. Petersburg, Russia) was used to assess the body composition and the nutritional status in hemodialysis patients. The obtained results were used for a prospective study of the correlation between patient survival and the results of the bioelectrical impendance analysis. A statistically significant difference in the overall survival and the survival of cardiovascular patients was shown to exist between patients with high and low body fat.

A prototype system for programmed distraction with electrical stimulation of the osteotylus formation is presented. The basic circuit diagram of the system is described. The system implements a method for distraction force measurement using an inductive sensor. A software application for remote control of the limb lengthening procedure and visualization of the curve of bone tissue tension vs. distraction period is described.

A method for making knee joint ligament implants based on synthetic constructs manufactured from polyethylene terephthalate fibers with composite nanocoatings was developed. Coatings consisted of aqueous dispersions of multiwalled (MWNT) and single-walled (SWNT) carbon nanotubes and were applied to synthetic fibers using ultrasound and then fixed by laser evaporation. The SWNT-based composite nanocoating had a pore diameter of 10-20 nm, compared with 40-60 nm for the MWNT-based coating. In vitro studies of the proliferative activity of human fibroblasts (HFb) during colonization on the surface and between the synthetic fibers were performed. The greatest level of HFb proliferation was seen on synthetic constructs with composite nanocoatings based on MWNT with large pore size, at 55,435 cells, as compared with SWNT-based coatings (54,931 cells) and the control sample (54,715 cells), as assessed by fluorescence microscopy and the MTT test.

A mathematical model of the physical process of storage of platelet-containing transfusion media in polymer containers is described. The thermohydrodynamic approach is used. A method for calculation of the transition processes of temperature stabilization in the platelet concentrate is suggested. The results of calculation of characteristics of typical storage modes differing by their initial conditions are presented.