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Vícesvodová rozhodovací pravidla v rozměřování signálů EKG / Multilead decision rules in delineation of ECG signalsRichter, Zdeněk January 2012 (has links)
This work deals with ECG signal measuring and methods of its processing. It compares some of the QRS detection methods and describes some of the testing databases. In this work a detector of QRS complex is realized, it is based on the approach of zero crossings. Next section makes combination of results from separate leads to one, which improves efficiency of detection. One section of this work deals with design and realization delination of ECG signal. In the last part outputs of this delineation are compared with the results of the other authors.
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Vliv nově syntetizovaných léčiv na elektrickou aktivitu izolovaného srdce potkana / The effect of new synthetized drugs on electrical activity of rat isolated heartKorčáková, Ivona January 2017 (has links)
This thesis deals with the influence of the newly synthesized drug on the electrical activity of the isolated heart of rat. Part of the thesis is a theoretical analysis of the use laboratory animals in experiments and ethical aspects related to the use of laboratory animals. There is also an analysis of drug testing, test substances, electrocardiography and methods used to detect and measure ECG signal. The two algorithms used for the QT interval are automated. The QT interval is the main indicator of cardiotoxicity and is considered to be the gold standard in evaluating the effect of the drug. In the practical part the ECG records obtained at the Faculty of Medicine at Masaryk University in Brno are processed. These records are dimmed manually and automatically. The manual dimming was consulted with a specialist in cardiography and statistically processed. Statistical processing served to compare with the results of the automatic ECG measurement. The algorithm is used to automate the measurement, and the results are compared with the reference points obtained from cardiology experts and manual measurement results. This work serves as a pilot study for the development and testing of a new active substance.
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NOVEL PHYSICAL PHENOMENA IN CORRELATED SUPERFLUIDS AND SUPERCONDUCTORS IN- AND OUT-OF-EQUILIBRIUMAmmar, Kirmani A. 16 April 2020 (has links)
No description available.
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Påverkas EKG av hur man placerar extremitetsavledningarna?Jawad, Rihab January 2022 (has links)
Abstrakt: Inom vården används olika undersökningsmetoder för att kunna utvärdera hjärtats funktion. Elektrokardiografi (EKG) är en av de metoderna. EKG har många fördelar exempelvis är metoden tillgänglig, billig, riskfri och icke-invasiv. Vid vilo-EKG placeras tio elektroder på bestämda positioner på kroppen vilka ger upphov till 12 avledningar. Avledningarna indelas i två grupper: bröstavledningar och extremitetavledningar. Studiens syfte var att undersöka närmare om det finns skillnader som påverkar bedömningen av EKG:et i P- vågor, QRS- komplex och hjärtats elektriska axel (QRS el-axel) i extremitetavledningar mellan standardkoppling och två andra omkopplingar. Trettio frivilliga deltagare inkluderades i denna studie. För samtliga deltagare registrerades tre EKG:n. I det första EKG:et kopplades extremitetselektroderna enligt standardkopplingen. I det andra EKG:et kopplades armelektroder på höger och vänstra överarmar, vänster benelektroden kopplades på lårbenet. Det tredje EKG:et kopplades enligt Mason- Liker, förutom att höger benelektrod inte omplacerades. Vid alla tre EKG:na placerades bröstelektroderna enligt standardkopplingen. Förändringar i duration, amplitud, och QRS el-axel mellan dessa EKG:n undersöktes. Resultaten av studien visade att det inte fanns någon signifikant skillnad mellan dessa kopplingar i duration och amplitud i QRS-komplexen. Inte heller i durationen på P-vågen. Däremot påvisades en signifikant skillnad i QRS el-axel samt i amplitud på P-vågen för den ena omkopplingen.
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DYNAMICKÁ ANALÝZA ZÁKLADOVÉ KONSTRUKCE V INTERAKCI S PODZÁKLADÍM / DYNAMIC ANALYSIS OF THE SOIL-FOUNDATION INTERACTIONMartinásek, Josef Unknown Date (has links)
Thesis deals with problems of the soil-structure interaction. In the theoretical part is described the approach to mathematical modeling of structure-foundation-soil interaction. The subsoil models are further described in detail, including the models with piles (both static and dynamics models). In the next chapter there is described the dynamics theory of the systems with single or more degrees of freedom. There is also an analysis of propagation, reflection and refraction of mechanical one-dimensional waves (P-wave, S-wave) and spatial waves (P- wave, SV-wave, SH-wave) and waves in homogeneous half-space (R-wave L-wave). The numerical analysis is logically sorted from hand calculation of the parameter change influence on the modal characteristics to complex computational FEM model of the machine with a foundation on piles placed in the spatial block of soil. Numerical studies aim to determine the influence of the subsoil model on the modal characteristics and thus confirm the absolute necessity of the subsoil model in tasks of dynamics. The next goal is to determine the appropriate key parameters of the computational model: the size of finite element, suitable shape of subsoil model, suitable inclination of boundary condition and suitable boundary conditions. For creating of set of computational models was used language APDL in conjunction with ANSYS software interface. All used input files are listed in the Annex.
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Wellenlängenmultiplexing mit thermisch fixierten Volumenphasenhologrammen in photorefraktiven Lithiumniobat-Kristallen / Wavelength Division Multiplexing with Thermally Fixed Volume Phase Holograms in Photorefractive Lithium Niobate CrystalsBreer, Stefan 08 September 2000 (has links)
Wavelength division multiplexing (WDM) is essential for further enhancement of the transmission capacities of optical
telecommunication systems. Key devices in WDM networks are multiplexing/demultiplexing components, which enable
the combination/separation of several carrier waves with different wavelengths for the purpose of simultaneous
transmission through one optical fibre. These components can be realized using Bragg diffraction from volume
holographic gratings. Especially reflection holograms provide a pronounced wavelength selectivity which makes them
attractive for free-space WDM applications.
Holograms can be stored permanently in photorefractive lithium niobate crystals by the method of Thermal Fixing.
Heating of the crystal during or after the recording process and subsequent development by homogeneous illumination at
room temperature create nonvolatile holograms. The recording and development processes of Thermal Fixing in iron-
and copper-doped lithium niobate crystals were investigated. Macroscopic Gaussian-shaped intensity patterns were
used to analyse the origin of the fixing mechanism. Spatially resolved absorption measurements were performed to
determine the concentration profiles of electron traps (Fe II/III) and protons. Results of computer simulations were
compared with experimental results, which showed that protons can be found to work as compensators during hologram
recording at temperatures around 180 degree C. Nevertheless thermal fixing without protons was possible, another
compensation mechanism stood in. The obtained refractive-index changes were due to the electro-optic effect, other
contributions could be neglected.
With this detailed knowledge about thermal fixing, a two-channel demultiplexing unit was built by superposition of two
thermally fixed reflection holograms in an iron-doped lithium niobate crystal. For this purpose a special two-beam
interference setup with precisely adjustable writing angles was arranged in a vacuum chamber to eliminate thermally
induced phase disturbances of the holographic recording procedure. Continuous development of the holograms by
incoherent light was necessary. In the dark, the enhanced dark conductivity of the crystal used gave rise to a hologram
degradation within about one day. Large diffraction efficiencies were attained (intensity losses between 2.3 and 5.2 dB
only) uilizing crystals with high-quality polished surfaces. The crosstalk supression of the realized demultiplexer was >
25 dB, which is comparable with the performance of other multiplexing techniques like fibre Bragg gratings or
arrayed-waveguide gratings. The low polarization dependence of the demultiplexer can be improved by superposition of
two holograms for each channel.
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