132 research outputs found

    Motion symmetry evaluation using accelerometers and energy distribution

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    Analysis of motion symmetry constitutes an important area with many applications in engineering, robotics, neurology and biomedicine. This paper presents the use ofmicroelectromechanical sensors (MEMS), including accelerometers and gyrometers, to acquire data via mobile devices so as to monitor physical activities and their irregularities. Special attention is devoted to the analysis of the symmetry of the motion of the body when the same exercises are performed by the right and the left limb. The analyzed data include the motion of the legs on a home exercise bike under different levels of load. The method is based on signal analysis using the discrete wavelet transform and the evaluation of signal segment features such as the relative energy at selected decomposition levels. The subsequent classification of the evaluated features is performed by k-nearest neighbours, a Bayesian approach, a support vector machine, and neural networks. The highest average classification accuracy attained is 91.0% and the lowest mean cross-validation error is 0.091, resulting from the use of a neural network. This paper presents the advantages of the use of simple sensors, their combination and intelligent data processing for the numerical evaluation of motion features in the rehabilitation and monitoring of physical activities. © 2019 by the authors.Ministry of Health of the Czech Republic [FN HK 00179906]; Charles University in Prague, Czech Republic [PROGRES Q40]; project PERSONMED - European Regional Development Fund (ERDF) [CZ.02.1.010.00.017_0480007441]; governmental budget of the Czech Republi

    Steam turbine

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    Cílem této diplomové práce je návrh točivé redukce pro zadané vstupní parametry, která je paralelně zapojena s redukční stanicí. Dále se v této práci zabývám termodynamickým výpočtem stupně a výpočtem vybraných uzlů turbíny, zpracováním projekčního návrhu zapojení točivé redukce do parního oběhu. Práce je zakončena návrhovým řezem turbíny.Goal of this dissertation is design of rotary reduction for entered input parameters that it is connected in parallel with reducing station. Further I´m looking into thermodynamic calculation of stage and chosen parts of turbine, making of project design of connection of rotary reduction to steam circulation. Dissertation is concluded by designed cross-section of turbine.

    Permutation Entropy and Signal Energy Increase the Accuracy of Neuropathic Change Detection in Needle EMG

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    Background and Objective. Needle electromyography can be used to detect the number of changes and morphological changes in motor unit potentials of patients with axonal neuropathy. General mathematical methods of pattern recognition and signal analysis were applied to recognize neuropathic changes. This study validates the possibility of extending and refining turns-amplitude analysis using permutation entropy and signal energy. Methods. In this study, we examined needle electromyography in 40 neuropathic individuals and 40 controls. The number of turns, amplitude between turns, signal energy, and “permutation entropy” were used as features for support vector machine classification. Results. The obtained results proved the superior classification performance of the combinations of all of the above-mentioned features compared to the combinations of fewer features. The lowest accuracy from the tested combinations of features had peak-ratio analysis. Conclusion. Using the combination of permutation entropy with signal energy, number of turns and mean amplitude in SVM classification can be used to refine the diagnosis of polyneuropathies examined by needle electromyography

    Lymphocyte populations and their change during five-year glatiramer acetate treatment

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    Background The goal of this study was to determine the characteristics that are affected in patients treated with glatiramer acetate (GA). Methods A total of 113 patients were included in this study. Patients were treated with glatiramer acetate (subcutaneous injection, 20 mg, each day). Peripheral blood samples were obtained just prior to treatment as well as 5 years after GA treatment. All the calculations were performed with the statistical system R (r-project.org). Results After 5 years of treatment, a significant decrease was found in the absolute and relative CD3+/CD69+ counts, the absolute and relative CD69 counts, the relative CD8+/CD38+ count and the relative CD38 count. A significant increase was found in the absolute and relative CD5+/CD45RA+ counts and the absolute CD5+/CD45RO+ count after 5 years of treatment. Conclusion This study presents some parameters that were affected by long-term GA treatment

    Linear and Nonlinear EEG Synchronization in Alzheimer’s Disease

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    As is known, Alzheimer’s disease (AD) is associated with cognitive deficits due to significant neuronal loss. Reduced connectivity might be manifested as changes in the synchronization of electrical activity of collaborating parts of the brain. We used wavelet coherence to estimate linear/nonlinear synchronization between EEG samples recorded from different leads. Mutual information was applied to the complex wavelet coefficients in wavelet scales to estimate nonlinear synchronization. Synchronization rates for a group of 110 patients with moderate AD (MMSE score 10 to 19) and a group of 110 healthy control subjects were compared. The most significant decrease in mutual information in AD patients was observed on the third scale in the fronto-temporal area and for wavelet coherence within the same areas as for mutual information; these areas are preferentially affected by atrophy in AD. The new method used utilizes mutual information in wavelet scales and demonstrates larger discriminatory values in AD compared to wavelet coherence.Як відомо, хвороба Альцгеймера (ХА) пов’язана з прогресуючим когнітивним дефіцитом у результаті істотної загибелі нейронів. Зменшення міжнейронних зв’язків може проявлятись як зміни ступеню синхронізації електричної активності взаємодіючих мозкових структур. Ми використовували методику оцінки вейвлет-когерентності для оцінки лінійної або нелінійної синхронізації зразків ЕЕГ, відведених від різних локусів кори. Визначення індексів взаємної інформації використовувалося для оцінки нелінійної синхронізації згідно з комплексними вейвлет-коефіцієнтами за вейвлет-шкалами. Було порівняно ступені синхронізації ЕЕГ-активності в групі пацієнтів, що страждали на ХА помірної тяжкості (оцінки за MMSE від 10 до 19 балів), та в групі із 110 контрольних здорових суб’єктів. Найістотніші зменшення індексів взаємної інформації у пацієнтів із ХА спостерігалися по третій шкалі для фронто-темпоральної зони; зменшення вейвлет-когерентності відзначались у тих самих зонах, що й зміни взаємної інформації. Саме ці зони зазнають переважної атрофії при ХА. Використаний новий метод базується на оцінках взаємної інформації за вейвлет-шкалами та демонструє більшу дискримінаційну здатність в умовах ХА, аніж визначення вейвлет-когерентності

    THE DYNAMICS OF HAEMOSTATIC PARAMETERS IN ACUTE PSYCHOTIC PATIENTS: A ONE-YEAR PROSPECTIVE STUDY

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    Background: The primary goal of the present study was to replicate our previous finding of increased coagulation and thrombocytes activity in drug-naïve psychotic patients in comparison with healthy controls and ascertain whether the blood levels of thrombogenesis markers further increase over the course of a consecutive one-year antipsychotic treatment. Subjects and methods: We investigated the plasma levels of markers indicating activation of coagulation (D-dimers and Factor VIII) and platelets (soluble P-selectin, sP-selectin) in an antipsychotic-naive group of nineteen men and seventeen women with acute psychosis (age 28.1±8.0 years, body mass index 22.6±4.2), and thirty-seven healthy volunteers matched for age, gender and body mass index. In the patient group, we repeated these assessments after three months and again after one year of antipsychotic treatment. Results: D-dimers (median 0.38 versus 0.19 mg/l; p=0.00008), factor VIII (median 141.5% versus 110%; p=0.02) and sPselectin (median 183.6 versus 112.4 ng/ml; p=0.00005) plasma levels were significantly increased in the group of patients with acute psychosis prior to treatment compared with healthy volunteers. The plasma levels of sP-selectin varied significantly (p=0.016) in the course of the one-year antipsychotic treatment, mainly between 3 and 6 months after start of therapy. The plasma levels of D-dimers and factor VIII did not change significantly, D-dimers remained elevated in contrast to the healthy controls. Conclusions: Patients with acute psychosis had increased levels of markers of thrombogenesis in comparison to the healthy volunteers. The haemostatic parameters also remained elevated during the one-year antipsychotic treatment

    Mechanical recanalization in ischemic anterior circulation stroke within an 8-hour time window: a real-world experience

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    PURPOSE:We aimed to assess the safety and effectiveness of mechanical recanalization in patients with ischemic stroke in the anterior circulation within 8 h since symptoms onset and with unknown onset time. We compared time intervals <6 h vs. 6–8 h/unknown onset time, as only limited data are available for a time window beyond 6 h.METHODS:Our cohort included 110 consecutive patients (44 males; mean age, 73.0±11.5 years) with ischemic stroke in the anterior circulation due to the acute occlusion of a large intracranial artery who underwent mechanical recanalization within an 8-hour time window or with unknown onset time. All patients underwent unenhanced computed tomography (CT) of the brain, CT angiography of the cervical and intracranial arteries and digital subtraction angiography. Perfusion CT was performed in patients beyond a 6-hour time window/with unknown onset time. We collected the following data: baseline characteristics, presence of risk factors, neurologic deficit at the time of treatment, time to therapy, recanalization rate, and 3-month clinical outcome. Successful recanalization was defined as Thrombolysis in Cerebral Infarction score of 2b/3 and good clinical outcome as modified Rankin scale value of 0–2 points.RESULTS:Successful recanalization was achieved in 82 patients (74.5%): in 61 patients treated within 6 h (73.5%), 7 patients treated within 6–8 h (63.6%), and 13 patients with unknown onset time (81.3%). Good 3-month clinical outcome was achieved in 61 patients (55.5%): in 46 patients treated within 6 h (55.4%), 5 patients treated within 6–8 h (45.5%), and 10 patients with unknown onset time (62.5%). Recanalization success or clinical outcome were not significantly different between patients treated at different time windows.CONCLUSION:Our data confirms the safety and effectiveness of mechanical recanalization performed in carefully selected patients with ischemic stroke in the anterior circulation within 8 h of stroke onset or with unknown onset time in everyday practice

    Data styling in web mapping applications with a focus on environmental health

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    Interpretation of data visualized in maps strongly depends on the experience of map reader and on the way the data are presented. Styling the data is crucial especially when creating maps for users with weaker cartographic knowledge and map reading experience. Because web mapping applications make spa­tial data more accessible to general public, this issue requires special attention in terms of their design. Here we present a styling approach for designing a web mapping application that assembles huge amount of data related to the issue of environmental health, based on our own experience with creating a web mapping application available at https://uvp.geonika.sk/map/ (Department of Cartography… 2016). As the field of environmental health is multidisciplinary, it requires combination of data from various sources and of vari­ous types, topics and resolutions. Various data were compiled, requiring thoughtful approach to styling with regard to the users of the mapping application, who are supposed to be not only professionals (from the field of geography and geoinformatics as well as of medicine, epidemiology, environmental sciences etc.), but also general public. Many of such users do not possess adequate cartographic knowledge, which is the reason why the data styling had to reflect this limitation
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