


Том 50, № 6 (2017)
- Год: 2017
- Статей: 16
- URL: https://journals.rcsi.science/0006-3398/issue/view/14600
Theory and Design
Numerical Modeling of the Effects of a Flow-Diverting Stent on Hemodynamic Characteristics in a Cerebral Aneurysm
Аннотация
We report here studies on the influences of a flow-diverting stent on the hemodynamic characteristics in a cerebral aneurysm. Results obtained by simulation of hemodynamics in an aneurysm of complex shape before and after positioning of the stent are presented. Hemodynamic changes induced by positioning the stent are evaluated. These data are of use for supporting medical decisions in evaluations of stent effectiveness and selecting the flow-diverting stent.



Article
Effects of Nanosize Coatings Consisting of Two-Dimensionally Ordered Linear Chain Carbon on the Microbial Colonization of Bioprostheses
Аннотация
Creation of nanosize coatings from two-dimensionally ordered linear chain carbon (TDOLCC) on the surfaces of biological heart valve prostheses had no significant influence on the adhesion of clinical strains of microorganisms. However, studies of the viability of test cultures on modified biotissue surfaces showed that adherent staphylococcal cultures did not retain viability, with the exception of Staphylococcus saprophyticus. Viability results for Gram-negative cultures varied: from the absence of growth in the case of Klebsiella pneumoniae on biotissues with TDOLCC to continuous growth of strains of Pseudomonas aeruginosa and Acetinobacter baumannii on the same surfaces. Doping of TDOLCC coatings with nitrogen prevented test culture adhesion and colonization (except for Candida albicans) after artificial inoculation of modified bioprostheses with clinical strains of microorganism



Extraction of the Fetal Electrocardiogram Using Dynamic Neural Networks
Аннотация
This article presents a nonlinear dynamics model for discriminating the sources of the maternal abdominal elec-trocardiogram (aECG). The coefficients of the separating matrix were determined by training a neural network. This method provides efficient extraction of the fetal electrocardiogram (fECG) independently of the choice of recording point, input signal duration, or number of independent leads.



Experimental Studies of the Unevenness of Wear of Hip Joint Endoprostheses
Аннотация
A mathematical model of the physical process of storage of platelet-containing transfusion media in polymer con-tainers 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 char-acteristics of typical storage modes differing by their initial conditions are presented.



Laser Shock-Wave Destruction of the Mucous Membrane and Skin Tissues as a Method of Treatment of Pathological Processes in Gynecology
Аннотация
The article substantiates a new method of treatment of degenerative diseases in gynecology by controlled destruction with laser shock waves poorly absorbed by biological tissues. The shock-wave process is initiated using finely dispersed absorbing particles deposited on the surface of pathological tissues. Absorption of laser radiation by the particles leads to their explosion accompanied by generation of elastic waves. Propagation of these waves in the surface layer of the surrounding biological tissue leads to its destruction. Such destruction can provide a precision therapeutic effect with controlled depth and area.



Determination of the Composition of Liquid Polydispersions of Cylinder-like Microorganisms from the Laser Depolarization Degree
Аннотация
The degree of depolarization of light scattered in liquid dispersions of nanoparticles was experimentally shown to be independent of the nanoparticle concentration. A model of the dependence of the laser depolarization degree on the mean aspect ratio of liquid polydispersions of cylinder-like microorganisms was suggested. It was shown that the suggested model could be used for determining the relative concentration of spherical admixtures in composite liquid polydispersions.



A Method for Noninvasive Diagnostic Examination of the Tympanic Membrane Using Probing Polyharmonic Sound Signals
Аннотация
A new method for noninvasive examination of the tympanic membrane based on the detection and processing of reflected polyharmonic sound signals is suggested together with a hardware system for its implementation in otolaryngological practice.



A Decision Support System for Prescription of Non-Medication-Based Rehabilitation
Аннотация
The construction of a recommendation system for selecting one of five non-medication-based rehabilitation complexes for participants in armed conflicts and emergencies is described. Rehabilitation techniques developed at the Tomsk Science Research Institute of Balneology and Physiotherapy prevent potential chronicization of pathological processes, increase the body’s adaptive reserves, and improve quality of life in those affected by emergencies. A set of features was determined for each complex, providing the most precise identification of each complex. The principle underlying the construction of the recommendation system is instrumental in nature and the system could be used not only in rehabilitation and treatment centers, but also in other healthcare institutions.



A Multichannel Analyzer of Meridian Structures of the Human Body Based on AFE Interfaces
Аннотация
The paper considers technical implementation of the devices for examining the energy state of the body’s meridian structures based on analog front-end (AFE) interfaces used for measuring the impedance of biological objects. The application of AFE chips improves the accuracy of measurements, while reducing the cost of the devices for reflex diagnostics.



Main Approaches to Creating Portable Automated Insulin Treatment Devices
Аннотация
We present here a review of the main approaches to creating portable devices for automated insulin therapy (AIT) for patients with type 1 diabetes mellitus. Existing devices and elements of AIT devices are classified and the main challenges associated with their use are discussed.



Portable X-Ray Diagnostic Devices for Dentistry
Аннотация
Features of the design and main properties of Russian and some non-Russian portable dental devices are described. Results from dosimetric studies of the first Russian portable dental apparatus of the Pardus family are presented. The potential use of portable technical X-ray machines in medicine is discussed.



Challenges in X-Ray Medical Diagnosis
Аннотация
This article analyzes current challenges in medical X-ray diagnosis. The design of a tunnel-type ionization chamber for recording dose and dose power over a wide range of bremsstrahlung radiation energies is discussed. We address questions related to the standardization of apparatus and the creation of a universal digital platform for X-ray radiotherapy instruments as the basis for building state-of-the-art, productive, safe, and reliable radiotherapy instruments with different operating modes in terms of power supply voltage and power, from kilowatts to tens of kilowatts. The article also considers the state of X-ray diagnosis in general and the quality of X-ray apparatus; the challenge of measuring technogenic radiation doses to patients; the use of digital technologies providing digital images of quality no less than and even greater than that of film-based images combined with significant reductions in effective doses during investigations, and the advantages of computer processing; the treatment of nosological groups of diseases by radiotherapy; the needs for radiotherapy systems based on medical linear electron accelerators; radiation safety for staff and the population; small-scale, mobile devices for X-ray investigations in patients; and legal and technical aspects. A special program for assessing the detective quantum efficiency of dynamic digital X-ray image detectors is proposed.



Experimental Determination of the Normalized Index of Hemolysis for the Sputnik Implantable Pediatric Rotary Blood Pump
Аннотация
The paper describes the procedure for evaluation of hemolysis induced by the Sputnik implantable pediatric rotary blood pump. In a series of five experiments the normalized index of hemolysis (N.I.H) for the Sputnik pump was found to be 0.0099 ± 0.0015 g/100 L.



The Effect of Rotor Geometry on the H−Q Curves of the Sputnik Implantable Pediatric Rotary Blood Pump
Аннотация
In this work, the effect of rotor geometry on the H−Q curves of the Sputnik implantable pediatric rotary blood pump was studied. Load sensitivity was calculated for different input angles of the pump impeller and diffuser blades. Hydraulic efficiency and shear stress were determined for each modification of the pump design. The study showed that variation of the input angles of the impeller and diffuser blades had a significant effect on the load sensitivity of the pump. An almost twofold increase in the load sensitivity was achieved (from 0.03420 to 0.05957 L·min−1·mm Hg−1).



Load Sensitivity of Rotary Blood Pumps under Static Pressure Conditions
Аннотация
Static-pressure head−flow characteristics were studied for six models of rotary blood pumps: Incor (BerlinHeart, Germany), HeartMate II (Thoratec Corp., USA), Sputnik and Sputnik 2 (JSC ZITC, Russia), Heartware HVAD (Heartware International, Inc., USA), and Duraheart (Terumo, Japan). Preload and afterload sensitivities were calculated for each pump model. Preload sensitivity was found to decrease in the maximum blood flow area. It was shown that preload sensitivity depends on the geometry of the pump rotor bundle rather than the type of the pump (centrifugal or axial-flow).



Simulation and Control of the H−Q Curves of the Sputnik Portable Ventricular Assist Device
Аннотация
A previously suggested approach to identification of pumping states of a rotary blood pump was verified using the head−flow curves of the Sputnik ventricular assist device. The curves were obtained using a mock circulatory loop under static conditions. The obtained results can be used for implementing a rotary blood pump control strategy intended to maintain the required flow rate and to identify the associated pumping states.


