Autonomic arousal detection and cardio-respiratory sleep staging improve the accuracy of home sleep apnea tests

Introduction: The apnea-hypopnea index (AHI), defined as the number of apneas and hypopneas per hour of sleep, is still used as an important index to assess sleep disordered breathing (SDB) severity, where hypopneas are confirmed by the presence of an oxygen desaturation or an arousal. Ambulatory polygraphy without neurological signals, often referred to as home sleep apnea testing (HSAT), can potentially underestimate the severity of sleep disordered breathing (SDB) as sleep and arousals are not assessed. We aim to improve the diagnostic accuracy of HSATs by extracting surrogate sleep and arousal information derived from autonomic nervous system activity with artificial intelligence.Methods: We used polysomnographic (PSG) recordings from 245 subjects (148 with simultaneously recorded HSATs) to develop and validate a new algorithm to detect autonomic arousals using artificial intelligence. A clinically validated auto-scoring algorithm (Somnolyzer) scored respiratory events, cortical arousals, and sleep stages in PSGs, and provided respiratory events and sleep stages from cardio-respiratory signals in HSATs. In a four-fold cross validation of the newly developed algorithm, we evaluated the accuracy of the estimated arousal index and HSAT-derived surrogates for the AHI.Results: The agreement between the autonomic and cortical arousal index was moderate to good with an intraclass correlation coefficient of 0.73. When using thresholds of 5, 15, and 30 to categorize SDB into none, mild, moderate, and severe, the addition of sleep and arousal information significantly improved the classification accuracy from 70.2% (Cohen’s κ = 0.58) to 80.4% (κ = 0.72), with a significant reduction of patients where the severity category was underestimated from 18.8% to 7.3%.Discussion: Extracting sleep and arousal information from autonomic nervous system activity can improve the diagnostic accuracy of HSATs by significantly reducing the probability of underestimating SDB severity without compromising specificity

Hydrogen peroxide production in an atmospheric pressure RF glow discharge: comparison of models and experiments

The production of (Formula presented.) in an atmospheric pressure RF glow discharge in helium-water vapor mixtures has been investigated as a function of plasma dissipated power, water concentration, gas flow (residence time) and power modulation of the plasma. (Formula presented.) concentrations up to 8 ppm in the gas phase and a maximum energy efficiency of 0.12 g/kWh are found. The experimental results are compared with a previously reported global chemical kinetics model and a one dimensional (1D) fluid model to investigate the chemical processes involved in (Formula presented.) production. An analytical balance of the main production and destruction mechanisms of (Formula presented.) is made which is refined by a comparison of the experimental data with a previously published global kinetic model and a 1D fluid model. In addition, the experiments are used to validate and refine the computational models. Accuracies of both model and experiment are discussed

Assessment of the capacity for flood monitoring and early warning in Enlargement and Eastern/ Southern Neighbourhood countries of the European Union

Flooding is a natural disaster that can damage large areas in the vicinity of rivers, and in the case of flash floods, also in the vicinity of smaller streams. The Global Risks Report 2017 lists extreme weather events, of which flooding is the main risk in most countries, as the risk with the second highest potential impact and the highest likelihood of occurrence. It furthermore seems likely that climate change will aggravate flood impacts in many regions. This report presents an assessment of the capacity for flood monitoring and early flood warning in 17 of the 22 countries which belong to the Eastern and Southern neighbourhood policy of the European Union and the enlargement candidate countries. Many of these receive external funding to improve their systems, but this is often on an ad hoc basis and through individual projects.JRC.E.1-Disaster Risk Managemen

Framework comparison for Java unit testing

Testovanie jednotiek zdrojového kódu, v tomto prípade tried programovacieho jazyka Java, je v dnešnej dobe súčasťou mnohých metodík vývoja software a jedným z predpokladov vytvorenia kvalitného programu. Nástroje uľahčujúce tento proces, čiže frameworky pre jednotkové testovanie a ich porovnanie, sú predmetom tejto práce. Vybrané boli konkrétne tieto: TestNG, JTiger a JUnit 4. Porovnanie prebieha na základe vopred definovaných kritérií. Vybrané nástroje, ktoré reprezentujú najkvalitnejšie a najpoužívanejšie frameworky, sú podrobne predstavené v samostatných kapitolách, kde sa kladie dôraz na ich konkrétne možnosti, implementované funkčnosti a špecifické prvky. Tie sú ilustrované na jednoduchých príkladoch. Samotné hodnotenie v závere práce v prvej časti porovnáva implementáciu spoločných funkčností, v druhej sa zameriava na špecifické prvky. U oboch skupín hodnotí kvalitu a pridanú hodnotu pre užívateľa daného nástroja

Some Computational Aspects of Vehicle Shell Frames Optimization Subjected to Fatigue Life

The paper deals with the implementation of the fatigue damage conditions into structural optimization process. The study considers a shell finite element structural analysis in conjunction with the multiaxial rainflow counting, the fatigue damage prediction and naturally the sizing (element thickness) optimizing design. We will analyze FE models under random excitation in time domain. The presented optimizing approach will be implemented into solution program compiled in Matlab

Numerical Algorithm for Beam Residual Stress Identification

The goal of the paper is the numerical study of the original hysteresis computational material models and their application in beam's bending theory. The paper presents the chosen differential material models and approaches based on step by step solution respecting the elastic and plastic conditions. In the centre of authors´ interest is the numerical method study of the plastic zones identification or study of residual stresses distribution in the beam's cross-section. The results obtained from new MATLAB's programs are compared with FEM models in ADINA