


Vol 50, No 3 (2016)
- Year: 2016
- Articles: 17
- URL: https://journal-vniispk.ru/0006-3398/issue/view/14584
Theory and Design
Designing a Total Artificial Heart Based on Rotary Blood Pumps
Abstract
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.



Article
Synergetic Control of Magnetic Bearings in Artificial Heart Ventricle Rotor
Abstract
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.



Control Algorithms for Rotary Blood Pumps Used in Assisted Circulation
Abstract
This work presents a review of the systems, methods, and algorithms for assisted circulation control published in the literature within the last five years. Control systems used in current clinical practice are described. Algorithms for evaluation, adjustment, operation mode control, and physiological control of the ventricular assist devices based on rotary blood pumps are discussed.



Real-time Algorithm for Detection of Atrial Fibrillation
Abstract
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.



Parameterization of the Regular Component of the ECG Signal for Diagnosis of the Critical States of the Cardiovascular System
Abstract
A procedure for parameterization of the regular component of the ECG signal is discussed. The procedure is used to determine the contribution of the regular component to the total spectral power of the signal. An algorithm for determination of the informative diagnostic parameters of the regular component of the ECG signal is suggested. Second-moment differential curves obtained for a number of functional states of the cardiovascular system are presented together with the informative diagnostic parameters calculated using these curves.



Neural Network Detector of ECG Signal Distortions
Abstract
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).



Processing of ECG Signals Detected by Portable Devices
Abstract
Specific features of processing ECG signals (ECS) detected by portable devices are considered. ECS enhancement against a noisy background is achieved by ECG decomposition with further selection of components forming the useful signal. Extremum filtering rather than empirical mode decomposition is used to reduce the computational effort without affecting the results of decomposition. This advantage of extremum filtering allows it to be used in portable electrocardiograph software.






A System for Monitoring Motion of Lower Limbs Used for Assessment of Patient’s Physical Rehabilitation
Abstract
The goal of this work was to describe the operational bioinstrumentation system Exomeasurer used for measurement of the range of motion of the lower limb joints in different activity modes. The system allows the human gait to be evaluated in the norm and pathology, as well as before and after therapy.



Control of Hemodialysis Therapy Based on the Bioelectrical Impedance Analysis
Abstract
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.



Stimulation of the Filling of Bone Defects by Terahertz Electromagnetic Irradiation
Abstract
Studies in an experimental group of 10 mongrel dogs addressed the stimulation of tibial defect filling by terahertz electromagnetic irradiation using an Orbita EHF therapy apparatus. Animals of the control group (n = 6) did not undergo this physical treatment procedure. These studies demonstrated stimulation of bone repair, apparent as inhibition of osteolytic processes leading to a significant (p = 0.017) decrease in the time to union in dogs of the experimental group.



A System for Automated Distraction with Electrical Stimulation of Osteogenesis
Abstract
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.



Use of Additive Techniques for Preparing Individual Components of Titanium Alloy Joint Endoprostheses
Abstract
Additive techniques, particularly selective laser melting (SLM), allow devices of complex shape to be made from a variety of metallic materials. Preparation of individual large joint endoprosthesis components using digital techniques, i.e., computerized tomography, three-dimensional scanning, three-dimensional printing, and subsequent preparation of prostheses from titanium by SLM, allows patients’ individual anatomical features to be taken into account and implants to be personalized, thus improving endoprosthesis implantation results. The present article demonstrates that individual components of a hip joint endoprosthesis can be made using titanium alloy BT6 powder using the patient’s computerized tomography data.



Knee Joint Ligament Implants with Composite Nanocoatings
Abstract
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.



Automatic Processing of Ultrasound Images of the Prostate
Abstract
A method is proposed for constructing functional models and their structural representation for the main stages of the automatic analysis of prostate gland ultrasound scan (USS) and transrectal ultrasound scan (TrUSS) data with the aim of increasing the quality and speed of diagnosis, prognostication, and treatment of prostate disease.



Modeling Processes of Storage of Platelet-Containing Transfusion Media in Polymer Containers
Abstract
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.



Erratum
Erratum to: Effect of Intensifying Screens on the Sensitivity and Resolution of X-Ray Imaging Systems


