http://radap.kpi.ua/en/radiotechnique/issue/feedVisnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia2018-03-31T08:40:44+03:00Oleg Sharpanradap@rtf.kpi.uaOpen Journal Systems<p>RADAP is a refereed non-profit both paper and electronic journal operated by the following people (all from the Radioengineering Faculty of Igor Sikorskiy Kyiv Politechnic Institute).</p>http://radap.kpi.ua/en/radiotechnique/article/view/1462The Analysis of Distributed Two-Layers Components in Three-Layer Planar Structure2018-03-30T17:40:57+03:00Yu. V. Rassokhinawgd888@gmail.comV. G. Krizhanovskiv.krizhanovski@donnu.edu.uaThe algorithms for analyzing of two-layer distributed discontinuities in the form of an inductive section in a microstrip transmission line and an H-shaped slot resonator with a transverse arrangement of "dumbbells" in its ground plane by the transverse resonance method are improved and developed. This method includes the mutual coupling of components that make up the discontinuity. According to the analysis results, the considered discontinuity is a multifunctional device and has scattering characteristics that contain simultaneously signal transmission and rejection. At this the two-layer discontinuity provides a wideband (up to 40 %) rejection with two-frequency characteristic of resonant reflection, and forms either two narrowband passband filters (about 3 %), or one wideband (up to 10 %) passband.2018-03-30T17:40:56+03:00Copyright (c) 2018 Rassokhina Yulia V., Krizhanovski Vladimir G.http://radap.kpi.ua/en/radiotechnique/article/view/1449Generalized Mathematical Model of Thin Asymmetric Inductive Diaphragm in Rectangular Waveguide2018-03-30T17:40:58+03:00O. S. Zakharchenkonovikos@bigmir.netS. Ye. Martynyukmart_1974@yahoo.comP. Ya. Stepanenkonovikos@bigmir.net<p><strong>Introduction</strong>. A significant number of microwave devices are constructed with applying the investigation results of thin asymmetric inductive diaphragm in rectangular waveguide. Increasing the requirements for the characteristics of these devices stipulates necessity to review the possibilities of existing electromagnetic methods in relation to increasing the accuracy of generalized scattering matrices calculation of this diaphragm. To obtain the high accuracy results of generalized scattering matrices calculation, a further study of integral equations method is represent considerable practical interest.<br /> <strong>Mathematical model of diaphragm</strong>. An accurate novel solution for general scattering matrix of infinitely thin asymmetric one-sided diaphragm in rectangular waveguide has been obtained. The problem is formed as the system of integral equations along the number of waves which is incident on the diaphragm. By applying the Galerkin’s method, each integral equation is reduced to system of linear algebraic equations relatively to coefficients of tangential electric field decomposition in diaphragm window by series of coordinate functions. The joint solution of all equations gives the distribution of tangential electric field in diaphragm window which is further used for finding the generalized scattering matrix.<br /> <strong>Numerical results.</strong> Two approaches for finding the coupling coefficients of coordinate functions of diaphragm window and eigen functions of waveguide are investigated. An estimation of limiting possibilities of developed realization of the integral equations method at approximation of tangential electric field in diaphragm window by series of eigen scalar functions has been carried out. It is shown that the calculated results of module and phase of fundamental wave transmission coefficient through diaphragm slowly go to exact values when the order of linear algebraic equation system is increased.<br /> <strong>Conclusions</strong>. The results of diaphragm investigation by using this algorithm have not only independent value but can be used to verify the accuracy of calculating the electromagnetic parameters of thin waveguide structures by using the general methods for solving electromagnetic problems, for example, FDTD. It is supposed that the results obtained in this work can be used in developing fast and high-precision calculation algorithms for frequency responses of multi-stage asymmetric waveguide structures.</p>2018-03-30T17:40:58+03:00Copyright (c) 2018 Martynyuk S. Ye., Stepanenko P. Ya., Zakharchenko O. S.http://radap.kpi.ua/en/radiotechnique/article/view/1445Analysis of Accuracy of Direct Digital Method of Correlative-Interferometric Direction Finding with Two-Dimensional Correlative Processing of Spatial Signal2018-03-30T17:40:58+03:00V. V. TsyporenkoTsyporenko.1985@gmail.comV. G. Tsyporenkotsyporenkovg@gmail.comV. V. Chukhovmps_cvv@ukr.netO. V. Andreievoleks.andreyev@gmail.comThe paper investigates the accuracy of the direct digital method of correlative-interferometric direction finding with reconstruction of spatial analytical signal in the aperture of linear antenna array. The main requirements for modern means of radio direction finding are to ensure their accuracy and noise immunity and ability to work in real time with minimum hardware expenditure. The typical operating condition of the direction finding means of random source of radio radiation as a part of modern systems of radiomonitoring is the presence of a complex electromagnetic environment, which dynamically changes. The perspective trend of the realization of radio direction finding in these conditions is the use of digital correlative-interferometric direction finders. The analytical expressions for the error variance of the estimation of signal delay and direction have been received. It has been shown that in addition to the basic classic control parameters such as the number of the direction-finding channels and the time of the radiation analysis, the error variance of the direction finding is also affected by the magnitude of the spatial shift of the correlation processing, by the view of the weighting function of the spatial digital radiation pattern and by the value of the normalized autocorrelative function. During the simulation the dependence family of the middle square deviation of estimation of the direction from the signal/noise ratio for the different values of the spatial shift is obtained. The results of the simulation have coincided with the assessment of the accuracy of the direction finding, obtained analytically.2018-03-30T17:40:58+03:00Copyright (c) 2018 Tsyporenko V. V., Tsyporenko V. G., Chukhov V. V., Andreev O. V.http://radap.kpi.ua/en/radiotechnique/article/view/1430Mathematical Modeling Method of Radiocommunication System Functioning (Multi-Tensor Method)2018-03-30T17:40:59+03:00I. Yu. Svydavoin2002@ukr.netA. P. Volobuievanvolobuiev@gmail.comD. A. Bukhalvoin2002@ukr.netIntroduction. In connection with appearance of new generation radio intelligence systems in many countries in the world, there is a discrepancy between the capabilities of existing radio communication systems to combat radio intelligence and the capabilities which needed to combat modern radio intelligence systems. This discrepancy requires the further development of electronic warfare methods of radio communication systems with new generation radio intelligence systems.<br /> One of the most promising directions of researches in this field is the mathematical modeling of radio communication systems functioning with the help of various tensor models with imposition restrictions on the intensity of information flows, timing and reliability of information passing, system load, etc. But the possibilities of this apparatus of mathematical modeling for solving the problems of new generation combating radio intelligence systems are somewhat limited (namely, it does not take into account the intelligence availability of individual radio stations, lines of direct communication and routes of information flows, which necessitates its further development).<br /> Therefore, the purpose of the article is the further development of the method of mathematical modeling of the functioning of the radio communication system on the basis of the apparatus of a tensor number in the interests of solving the multiway routing problem for adapting it to the problem of combating new generation radio intelligence systems.<br /> The article proposes a method for mathematical modeling of the radio communication system operation (a multi-tensor method), which is the basis for solving the problem of multiway routing and in addition to known restrictions of maintenance of acceptable average delay of information flow on route, required probability of timely delivery of information flow, acceptable deviation from average delay of information flow also considers restriction of route intelligence availability of information flows, which is essential military for radio communication. It is shown that the reduction of radio communication system model to the tensor type, based on the geometrization of its structure with the introduction of discrete space, allows us to describe the system with a tetravalent geometric object of mixed measurement – a multitenzer and to determine the routes of information flows with acceptable intelligence availability.2018-03-30T17:40:59+03:00Copyright (c) 2018 Svyda I.Yu., Volobuiev A.P., Bukhal D.A.http://radap.kpi.ua/en/radiotechnique/article/view/1446Neural Network of the gestosis diagnosis system2018-03-30T17:40:59+03:00M. P. Mustetsovbagan.v.o@gmail.comS. O. Bahanbagan.v.o@gmail.com<strong>Introduction</strong>. The work is devoted to the increase of the information content of the methods of express diagnostics of the state of the cardiovascular system of pregnant women by developing a diagnostic monitoring system and assessment of the state of hemodynamics of pregnant women due to the use of neural network technologies.<br /> Currently, gestosis is one of the most urgent problems of modern obstetrics due to the prevalence and complexity of etiopathogenesis, the absence of early and reliable diagnostic criteria, effective prevention and treatment measures, high maternal and perinatal morbidity and mortality, as well as large economic costs of intensive care for patients. The proposed approach to optimization of the diagnosis of preeclampsia using registration key hemodynamic parameters, which allows to objectively evaluate the hemodynamics in pregnant women with preeclampsia, to determine the type of hemodynamics in pregnant women and to monitor the effectiveness of the therapy.<br /> <strong>Neural network technologies for the analysis and processing of medical data</strong>. The synthetic structure of the artificial neural network has shown the effectiveness of its use for diagnosis of gestation, using real clinical data. The basis of the diagnostic system was the artificial neural network, using the application package Statistica.<br /> <strong>Hybrid network as an adaptive system of neuro-fuzzy output system</strong>. In order to diagnose gestosis, we synthesized a neural network that allowed us to classify the pathologies of pregnant women on the basis of oscillometric data, using neural-fuzzy modeling in the Matlab environment. In the framework of this work, the ANFIS editor was used to build the model that would help create or load a specific model of the adaptive neuro-fuzzy inference system, perform its training, visualize its structure, change and adjust its parameters, and use the configured network to obtain the results of fuzzy inference. The findings of the tests, show that with the introduction of 7 basic parameters characterizing the state of a pregnant woman, the produced result is in the form of a definition of the type of hemodynamics and the degree of gestosis. The determination of the type of hemodynamics and the degree of gestosis allows the diagnostician and the obstetrician-gynecologist to assess the critical state of the pregnant woman at the time of the study and to take the necessary treatment measures.<br /> <strong>Conclusion</strong>. In order to diagnose gestosis, a neural network was synthesized, which allowed classifying the pathology of pregnant women using neuro-fuzzy simulation in a Matlab environment. The application of the proposed system helps choose the tactics of treating a patient diagnosed with gestosis according to individually selected therapy, monitoring its effectiveness, which will have a positive effect on the course and outcome of pregnancy; most importantly, controlling the state of maternal hemodynamics will eliminate the unreasonable use of medications.2018-03-30T17:40:59+03:00Copyright (c) 2018 Mustetsov M. P., Bahan S. O.http://radap.kpi.ua/en/radiotechnique/article/view/1458Segmentation of anatomical heart structures in Ensite Verismo software for radiofrequency ablation of arrhythmogenic tissues2018-03-30T17:40:59+03:00V. V. Filimonovaviktoryafv@gmail.comM. M. Sychykmarina.sychik@gmail.comL. D. Tarasovalarisa.tarasova.dmitrievna@gmail.comB. B. Kravchukkravchukb@hotmail.comB. V. Batsakbatsak-bogdan@mail.ruA. V. Pokanievychpokanevich78@gmail.com<strong>Review of the problem</strong>. The relevance of the research is the need of a high-quality imaging of the left atrium anatomy for the effectiveness of radiofraquency ablation of arrhythmogenic tissue of the myocardium in real time. For its safety it is important to assess the attachment of the esophagus to the wall of the heart.<br /> Nowadays, methods of visualization of real anatomical structures are dynamically developed on the basis of data processing of DICOM computer and magnetic resonance imaging, including for the reconstruction of 3D anatomy of the heart.<br /> <strong>Purpose of research</strong>. The task of the research was to construct a three-dimensional model of the anatomical structures of the heart and the nearby organs (pulmonary veins, esophagus) in EnSite Verismo software environment (St.Jude Medical, USA) and to implement the technique in clinical practice in order to improve the accuracy of visualization, safety and efficacy of RFA in X-ray conditions in real time.<br /> <strong>Metodology</strong>. The research was carried out at the M.M. Amosov National Institute of Cardiovascular Surgery Ukraine NAMS of Ukraine with the use of modern specialized high-tech medical equipment and clinical materials, computer tomography images (CT) of the patient's heart N. obtained in the radiation diagnostics department and data of the electroanatomic mapping of the patient's heart in the department of treatment of arrhythmias with X-ray surgery.<br /> The approach for conducting RFA with the EnSite Verismo software was implemented using the following algorithm:<br /><ol><li>Receiving and preserving CT scans of the patient in the DICOM format.</li><li>Downloading "gray" images into the EnSite Verismo software.</li><li>Construction of a 3D model of anatomical structures of the heart, pulmonary veins and esophagus by the segmentation of CT images.</li><li>Export of model to the EnSite NavX system (St. Jude Medical, USA).</li><li>Combination of a segmented model and electroanatomical map in the EnSite NavX system for further radiofrequency ablation.</li></ol>An algorithm for 3D segmentation of the left atrium, pulmonary veins and esophagus in the EnSite Verismo software is developed. It is based on the threshold method of splitting the image into an area for which a certain homogeneity criterion is fulfilled.<br /> <strong>Result and conclusions</strong>. The developed algorithm for segmentation of the left atrium, pulmonary veins and esophagus for the EnSite Verismo allows for the construction of an exact anatomy of structures. The 3D model of individual anatomy of the heart provides the information for surgeon during RFA about the features of the structure of the left atrium: the location of the pulmonary veins in order to avoid vein stenosis; the localisation of the esophagus in order to apply ablation very carefully, so as not to make the perforation of the esophagus. A 3D model, supplemented by an electro-anatomical map of the left atrium that shows, in addition to anatomy, the order of activation of heart miocardium and localization of arrhythmia, will increase the efficiency and safety of RFA.2018-03-30T17:40:59+03:00Copyright (c) 2018 Filimonova V.V., Sуchуk M.M., Tarasova L. D., Kravchuk B.B., Batsak B.V., Pokanievych A.V.http://radap.kpi.ua/en/radiotechnique/article/view/1464Dynamics of Bioimpedance Parameters on Three Frequencies During Ultrafiltration2018-03-31T07:26:01+03:00O. B. Sharpansharpan@tor.kpi.uaV. S. Mosiychukmvs@ros.kpi.uaM. O. Arkhypskaarkhipskaya@gmail.comB. V. Tkachukbog.tkachuk@gmail.comR. S. Tomashevskyiromiocat.khpi@gmail.com<strong>Background/Aim</strong>. At present, methods based on the analysis of non-invasively measured parameters of electrical bioimpedance for the diagnosis of the patient's biohydrality are of interest. The purpose of this article is to investigate the dynamics of electrical impedance parameters (module, phase angle, active and reactive components) of the human body during ultrafiltration of programmed hemodialysis at three frequencies of 20 kHz, 100 kHz, 500 kHz.<br /> <strong>Equipment and Methods</strong>. For the research was used the hemodialysis system Fresenius Medical Care 5008C. This system provided the implementation of the ultrafiltration procedure profile. Also was used the hardware and software complex of monitoring bioimpedasometry TOR-M-1, adapted for hemodialysis procedure and conditions. Using these equipment the dependences of the modulus Z, the phase angle $ \varphi $, active R and the reactive X impedance components corrected to the body length of the patient H, the region of distribution of the bioimpedance vector relative to the tolerance ellipses and the dynamics of these parameters, depending on the volume of the ultrafiltrate and the profile of the ultrafiltration procedure were studied.<br /> <strong>Dynamics of bioimpedance parameters</strong>. It was found that during the ultrafiltration has a characteristic complex nonlinear behavior of the impedance parameters for each individual patient. The intensity of this nonlinearity increases with increasing frequency. It is expressively observed at higher frequencies of 100 kHz and 500 kHz.<br /> <strong>Interpretation of Impedance Dynamics with Tolerance Ellipses</strong>. The non-stationary oscillatory character of the parameter dynamics testifies to the complexity of the individual transient processes of redistribution of volumes of human water sectors in the process of hemodialysis and associated with changes in the ratio of intracellular, extracellular fluids and blood, the structural composition of the liquid. This causes fast flowing changes in active conductivity in the intercellular environment and reactive conductivity due to the action of polarization processes on the dielectric structures of biological tissues.<br /> <strong>Discussion and Conclusion</strong>. Measurements and cumulative analysis of the parameters of electrical impedance directly in the process of hemodialysis allows to objectively monitor the progress of the patient's functional state in real time with an assessment of the presence or absence of a `dry weight 'level, evaluate the nature of the processes of redistribution of intracellular and extracellular sectors of the body and blood, and the differences in the course of the process of ultrafiltration of patients. This can be the basis, if necessary, for promptly adjusting the ultrafiltration process. Widening of the impedance measurement bandwidth enhances the diagnostic capabilities of such monitoring and the timely correction of the ultrafiltration procedure.2018-03-30T17:41:00+03:00Copyright (c) 2018 Sharpan O. B., Mosiychuk V. S., Arkhypska M. O., Tkachuk B. V., Tomashevskyi R. S.http://radap.kpi.ua/en/radiotechnique/article/view/1441Impedance measurement front-end based on signal four-phase detection2018-03-30T17:41:00+03:00G. I. Baryloskb_mp@ukr.netR. L. Holyakaholyaka@yahoo.comI. N. Prudyusiprudyus@polynet.lviv.uaS. E. Fabirovskyyfabirovskii@gmail.comInternet of Things (IoT), a new direction in information and communication systems, has a significant impact on the development of novel electronics devices. Further progress in the field of IoT devices is conditioned by the development of sensor devices, and in particular, analog front-ends and signal converters for IoT sensors. High sensitivity and wide range applications of IoT sensors can be achieved by methods of impedance spectroscopy. Compared with other methods of physical research, impedance spectroscopy and based on it IoT sensor devices provide ease of implementation, high energy efficiency, good resolution and selectivity. In this paper, we present results of the development and model study of the impedance measuring transducer using the four-phase signal integration method.<br /> The implementation of impedance spectroscopy assumes a transition from frequency plots to plots on the complex plane, called as Nyquist plots. The data obtained in this paper are based on the SPICE (Simulation Program with Integrated Circuit Emphasis) model studding methodology, which compares small signal Alternative Current Analysis with large signal Transient Analysis. During the Alternative Current Analysis, Nyquist impedance plot are obtained in the idealized case, and during the Transient Analysis the active ReZ value and reactive ImZ impedance components are calculated for the actual parameters of the measuring transducers and the form of the activating signals. <br /> We have proposed a new solution of the impedance measuring transducer based on the four-phase signal commutation and integration method. This method consists in the formation of four informative signals, namely, the voltages $V_{Q1}$, $V_{Q2}$, $V_{Q3}$ та $V_{Q4}$, each of which corresponds to the integration results in the corresponding four phases of the activation signal. In these phases, or time t, the sign functions $A_{Q1}(t)$, $A_{Q2}(t)$, $A_{Q3}(t)$, $A_{Q4}(t)$ of synchronous detections are used: $A_{Q1}(t)=1$ at $t=[0...\pi/2]$; $A_{Q2}(t)=1$ at $t=[\pi/2...\pi]$; $A_{Q3}(t)=1$ at $t=[\pi...3\pi/2]$; $A_{Q4}(t)=1$ at $t=[3\pi/2...2\pi]$. In other time these sign functions are equal 0. Output signals of the impedance measuring transducer, namely, voltages of active $V_{RE}$ and the reactive $V_{IM}$ components are formed by adding and subtracting the numerical values of the above four voltages: $V_{RE}=V_{Q1}+V_{Q2}-V_{Q3}-V_{Q4}$; $V_{IM}=V_{Q1}-V_{Q2}-V_{Q3}+V_{Q4}$. The main units of the impedance measuring analog front-end are a synchronous quadrature detector and an integrator or filter.<br /> In comparison to traditional two-phase detection, four-phase detection we have proposed allows avoiding intermediate signal transducing, which provides a significant simplification of impedance measuring transducing. This simplification is achieved by directly integrating the instantaneous value of the $I_{Z}(t)$ current. Important dependences of the measuring transducer output voltages with four-phase integration on the operational amplifiers bandwidth are obtained.<br /> Results presented in the article are important for developing a new generation of microelectronic IoT sensor devices based on impedance spectroscopy methods. Main areas of application of such sensor devices are materials science, biochemistry, instrumentation, avionics, ecology, etc.2018-03-30T17:41:00+03:00Copyright (c) 2018 Barylo G. I., Holyaka R. L., Prudyus I. N., Fabirovskyy S. E.http://radap.kpi.ua/en/radiotechnique/article/view/1478A Computational Model of Electrophysiological Properties of Cardiomyocytes2018-03-31T08:40:44+03:00N. G. Ivanushkinan.ivanushkina@gmail.comE. O. Ivan'kokoondoo@gmail.comYu. V. Prokopenkoyu.prokopenko@gmail.comA. Redaellialberto.redaelli@polimi.itV. I. Tymofieievtimofkpi@gmail.comR. Visoneroberta.visone@polimi.it<strong>Introduction</strong>. The method of electrical analogies for the analysis of bioelectric dynamic processes in cardiomyocytes is used in the study. This method allows for replacing investigation of phenomena in non-electrical systems by research of analogous phenomena in electrical circuits. The investigation of time processes in cardiac cells is based on the solution of the system of ordinary differential equations for an electrical circuit. Electrophysiological properties of cardiomyocytes such as refractory period, maximum capture rate and electrical restitution are studied.<br /> <strong>Mathematical modeling</strong>. Computational simulation of the action potential and currents for $K^+$, $Na^+$, $Ca^{2+}$ ions in cardiomyocytes is performed by using the parallel conductance model. This model is based on the assumption of the presence of independent ion channels for $K^+$, $Na^+$, $Ca^{2+}$ ions, as well as leakage through the membrane of cardiac cell. Each branch of the electrical circuit reflects the contribution of one type of ions to total membrane current.<br /> <strong>Results</strong>. The obtained electrical restitution curves for ventricular and atrial cardiomyocytes are presented in the paper. The proposed model makes it possible to identify the areas with the maximum slope on the restitution curves, which are crucial in the development of cardiac arrhythmias. Dependences of calcium current on stimulation frequency for atrial and ventricular cardiomyocytes are obtained. Analysis of the kinetics of calcium ions under various protocols of external influences can be useful for predicting the contractile force of cardiomyocytes.<br /> <strong>Conclusion</strong>. The results of calculations can be used to interpret the experimental results obtained in investigations of cardiomyocytes using the "laboratory on a chip" technology, as well as in the design of new experiments with cardiomyocytes for drug screening, cell therapy and personalized studies of heart diseases.2018-03-30T17:41:01+03:00Copyright (c) 2018 Ivanushkina N., Ivanko K., Prokopenko Yu., Redaelli A., Timofieiev V., Visone R.http://radap.kpi.ua/en/radiotechnique/article/view/1442Influence of the Matrix Structure of the Modulator and Detector on the Optical Spectrum Analyzer Output Signal2018-03-30T17:41:01+03:00V. H. Kolobrodovthermo@ukr.netG. S. Tymchikdeanpb@kpi.uaV. I. Mykytenkov.mikitenko@nil-psf.kpi.uaM. S. Kolobrodovkolobrodov_n@ukr.netM. M. Lutsiukfagot1993@gmail.comIn this article, we investigate the physical and mathematical model of a coherent optical spectrum analyzer (COSA), which uses a matrix light modulator and a matrix detector as input and output devices. This model allows to define distortions in the output signal of the spectrum analyzer and the error in determining the signal spatial frequency. The study of this model showed that form of the signal at the COSA’s output depends on the pixels sizes of modulator and detector matrices, as well as on the aberrations of the Fourier lens entrance pupil diameter. The output signal is a convolution of an ideal input signal spectrum with a discrete spatial transmission spectrum of the modulator, which is followed by convolution with a discrete sensitivity of the matrix detector. This means that the spectrum of the signal under investigation is distorted by the spatial spectrum of the modulator and the matrix structure of the matrix detector. An important feature of the signal is its independence from the phase shift, which is caused by the displacement of the modulator center relative to the optical axis of the spectrum analyzer. The output signal of COSA consists of an infinite number of diffraction maximum, each of which has three maximum, the distance between which is proportional to the spatial frequency of the test signal. The position (frequency) of the maximum is determined by the pixel size, and their width by the size of the modulator. Obtain the formulas for determining the spatial frequency of the test signal, which differ substantially from the traditional formula and depend on the position of the central and lateral maximum in the diffraction maximum. The error in measuring the frequency depends on the size of the detector pixel, focal length of the Fourier lens, and the modulator matrix size. Developed the method for determining the error in measuring the spatial frequency of a harmonic signal. The error is defined as the difference between the true frequency corresponding to the position of the center of the diffraction maximum and the measured frequency corresponding to the position of the pixel center which has the maximum signal.2018-03-30T17:41:01+03:00Copyright (c) 2018 V. G. Kolobrodov, G. S. Tymchik, V.I. Mykytenko, M.S. Kolobrodov, M.M. Lutsiuk