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Рассмотрена возможность использования оптоакустических методов при воздействии лазера Nd: YAG с длиной волны 1064 нм для оценки уровня агрегации эритроцитов в крови человека. С этой целью было проведено 2D-моделирование с агрегированными образцами крови, содержащими модели эритроцитов, представляющих собой сферические поглотители оптического сигнала. При воздействии оптического излучения на жидкость содержащую поглотители сферической формы, тем самым они подвергаются термоупругим расширениям и генерируют ультразвуковые колебания, изучая которые можно определить свойства этих поглотителей их размеры и количество. В работе разработана математическая модель агрегации эритроцитов методогексагональной упаковки. Рассчитан средний радиус кластеров для количественного определения среднего размера агрегата. Разработана модель формирования оптоакустического сигнала от модельных образцов крови с агрегированными эритроцитами, для изучения того, как будет изменяться амплитуда оптоакустического сигнала и спектр мощности в зависимость от уровня агрегации эритроцитов. В результате моделирования установлено, что амплитуда оптоакустического сигнала возрастает с увеличением уровня агрегации и снижается частота спектральной мощности сигнала. Проведенные исследования в области оптоакустики являются продолжением исследований направленных на создание оптоакустического цитомера., The possibility of using the optoacoustic methods under the influence of Nd: YAG laser with a wavelength of 1064 nm is examined to assess the level of erythrocyte aggregation in human blood. To this end, 2D modeling was carried out with aggregated blood samples containing models of erythrocytes, which are spherical absorbers of the optical signals. Under the influence of optical radiation on the liquid containing absorbers of spherical shape, thereby they undergo thermo-elastic expansions and generate ultrasonic vibrations, studying which one can determine the properties of these absorbers in their sizes and amounts. The mathematical model of erythrocyte aggregation of the hexagonal packing method has been developed. The average radius of clusters is calculated for the quantitative determination of the average size of the aggregate. A model for the formation of an optoacoustic signal from model blood samples with aggregated erythrocytes has been developed to study how the amplitude of the optoacoustic signal and the power spectrum will vary depending on the level of aggregation of red blood cells. As a result of the simulation it was established that the amplitude of the optoacoustic signal increases with the level of aggregation and the frequency of the spectral power of the signal decreases. The research carried out in the field of optoacoustics is a continuation of the research aimed at creating an optoacoustic cytometer.

The article presented the results of electroencephalography (EEG) signal processing in a case study of neuro-electrostimulation application for patients suffering from depression. Neuro-electrostimulation was performed by the SYMPATHOCOR-01 device in two modes - multichannel and single-channel stimulation. The analysis of changes in the EEG activity maps during neuro-electrostimulation course was carried out. The common conclusion for all patients is an increase in the homogeneity for the distribution of spectral power density for EEG signals. A quantitative method for estimating the level of the brain zones activation was proposed. For patients from the multichannel stimulation group, an increase in the activation level was observed. It was noted that for patients from the single-channel stimulation group there were zones in which a significant decrease in the level of activation was observed. © 2019 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved. Russian Foundation for Basic Research, RFBR: 18-29-02052 Government Council on Grants, Russian Federation The EEG signals data acquisition within the study (Chapter 2) was supported by the Act 211 of the Government of the Russian Federation (contract no. 02.A03.21.0006). The EEG signals data processing (Chapter 3) was funded by RFBR (project no, 18-29-02052).

In this paper, in order to analyze the limits of CNTFET devices, we study the behavior of a differential amplifier based on CNTFET for application between 50 GHz and 500 GHz, determining the highest gain achievable with low noise level. In particular the examined circuit presents a differential input and single ended output, in which each CNTFET is composed by a single CNT, having the same diameter. The analysis is done without considering embedding parasitic effects since our aim is to study the intrinsic limits of CNTFET. We find a solution that is near optimum for gain and noise. In particular we obtain that, using CNTFETs whose channel length is 25 nm, it is possible to reach 27.0 dB gain at 50 GHz and 19.7 dB gain at 500 GHz with a noise spectral power density noise 95 nV/Hz and 85 nV/Hz respectively.

WOS: 000379349600008, Objective: Hyperemesis gravidarum (HG) is a disease characterized by excessive vomiting and nausea during pregnancy. It differs from normal pregnancy where simple nausea and vomiting are seen frequently with unknown cause. The place and role of the brain in HG is unknown. Materials and Methods: Thirty-three healthy pregnant women and 30 patients diagnosed with HG admitted to Selcuk University Faculty of Medicine, Obstetrics and Gynecology Department were included and electroencephalograph (EEG) signals of all patients obtained at Neurology Department were examined. These signals were evaluated with high math and examined with developed engineering methods. The sampling frequency of the EEG was 200 Hz. Data were obtained in the frequency-power axis using 0.1 Hz frequency resolution, Hamming windowing, and 0.5 overlap ratio with signals on the time axis on all channels. All sub-bands have formed with unearthed power spectral density as delta, theta, alpha, and beta and after being created was calculated spectral densities. Results: As a result, while showing significant changes as delta band for Fp1F3, theta band for C3P3, F3C3, Fp1F3, P3O1, T5O1, for other channels and sub-bands has not seen any significant changes with regard to average power spectral density. Conclusion: HG and normal pregnancies, when examined in terms of power spectral density, abnormalities were observed in the EEG signals in the left hemisphere frontal area of the delta band, fronto-centro-parietal, and parietal-occipital areas of the theta band. In light of the literature, neither cerebral abnormalities in HG could be displayed nor the place of abnormality could be shown. However, this study is the first to clearly show abnormalities of theta-delta band activity and differences of locations in the left cerebral hemisphere.

Рагозин Андрей Николаевич, канд. техн. наук, доцент кафедры инфокоммуникационных технологий, Южно-Уральский государственный университет, г. Челябинск; ragozinan@susu.ru. Тележкин Владимир Федорович, д-р техн. наук, профессор кафедры инфокоммуникационных технологий, Южно-Уральский государственный университет, г. Челябинск; telezhkinvf@ susu.ru. A.N. Ragozin, ragozinan@susu.ru, V.F. Telezhkin, telezhkinvf@susu.ru South Ural State University, Chelyabinsk, Russian Federation Currently, spectral analysis occupies an important place among the various methods of investigation of heart rate variability. The result of the spectral analysis is a spectral power density of the study of heart rate variability, which serves as an indicator of the various mechanisms of regulation of the cardiovascular system. A common classical nonparametric method for calculating the spectral power density is the Welch periodogram method, with its underlying fast Fourier transform procedure. This method calculates and then averages a set of spectra obtained from timesequentially shifted segments of the initial dependence of heart rate variability. The resulting dependence of the spectral power density of the signal is a statistical estimate and characterizes the dependence of the distribution of the average power of the signal from the frequency. With this approach, the analyzed dependence of heart rate variability is considered as the realization of some random process. In this case, the amplitude of a peak of the dependence of the spectral power density is not associated with a constant amplitude (or its square) harmonics with a certain frequency and reflects a certain constant rhythm at this frequency, but is associated with the average measure of oscillatory activity (power) analyzed dependence heart rate variability at the frequency under consideration. В настоящее время среди различных методов исследования вариабельности сердечного ритма важное место занимает спектральный анализ. Результатом спектрального анализа является спектральная плотность мощности исследования вариабельности сердечного ритма, служащая в качестве индикатора различных механизмов регуляции сердечно-сосудистой системы. Распространённым классическим непараметрическим методом вычисления спектральной плотности мощности является периодограммный метод Уэлча, с лежащей в его основе процедурой быстрого преобразования Фурье. При этом методе рассчитывается и затем усредняется набор спектров, полученных на последовательно смещённых во времени сегментах исходной зависимости вариабельности сердечного ритма. Получаемая при этом зависимость спектральной плотности мощности сигнала является статистической оценкой и характеризует зависимость распределения в среднем мощности исследуемого сигнала от частоты. При таком подходе анализируемая зависимость вариабельности сердечного ритма рассматривается в качестве реализации некоторого случайного процесса. В этом случае амплитуда какого-либо пика зависимости спектральная плотность мощности не связана с постоянной амплитудой (или её квадратом) гармоники с определённой частотой и отражающей некоторый постоянный ритм на этой частоте, а связана со средней мерой колебательной активности (мощностью) анализируемой зависимости вариабельности сердечного ритма на рассматриваемой частоте.

Grado en Ingeniería en Electrónica Industrial y Automática

Int Soc Bipolar Disorders

Рассмотрена возможность построения оптимальных предыскажающих и корректирующих фильтров с учетом их физической реализации.

This thesis describes the investigation of the surface morphology evolution as a function of time and variables such as temperature, concentration of organic additives and current density. To extract the morphological information, digital analysis of AFM images was performed. It involved scaling analysis and spectral power density. The morphological information contained in the image can be encoded in a small set of parameters--scaling exponents. The spectral power density gives insight into smoothing and roughening mechanisms dominating the surface growth. Nodulation was also studied in this thesis. The affect of anode passivation on the nodulation of the deposited Cu was identified in the laboratory. A high concentration of glue initiates nodulation during Cu electrodeposition. Three models are discussed to elucidate the nodulation mechanisms. We have demonstrated that different mechanisms leave a characteristic signature in the nodule morphology. These characteristics of nodules may be used to identify the cause of nodulation.

1/f noise investigation was performed on n-GaN epitaxial layer grown on sapphire. The variation of spectral power density of voltage fluctuations density was observed as a function of frequency (100-50 Hz) and it showed the 1/f spectra. This type of behavior was attributed to the presence of traps. The variation in spectral power density of voltage fluctuations with temperature was also observed with in the temperature range 80 K and 300 K and it was found to be slightly increasing with temperature. It was attributed to the trapping-detrapping process of charge carriers by the defects. Four probe configuration was used for noise measurement and contacts were made with indium. To check the stability and ohmic behavior of contacts, I-V measurements were performed with in the temperature range 80-325 K. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/22017