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Optical Signals of Brain
Konopková, Renata ; Otáhal, Jakub (advisor) ; Kittnar, Otomar (referee) ; Valeš, Karel (referee)
Intrinsic optical signals are the signals reflecting changes in transmittance or reflectance of the light illumitating the tissue. Registration of such changes can be applied for the detection of physiological condition in the slices of biological tissues (in vitro) or in the whole animal (in vivo). The aim of this project is to introduce this topic and show different possibilities for the detection of changing optical properties of nervous tissue both in vitro and in vivo. The detection system of both light source and attachment of the optical fibre to the skull of the animal for in vivo experimets have been designed. The proper experimental part of the study have been done in hippocampal tissue slices and shows the correlation of the tissue activity and the optical signal at level of ion channels, glutamatergic synaptic activity, glial component of the signal and mitochondrial signal. We are dealing with the source of the noice that we record while detecting rather subtle changes of optical properties. We are indroducing the software VisionBrain for synchronous detection of both electrical and optical changes. Keywords: Intrinsic optical signals, hippocampus, imaging, biomechanics
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Contributions to Volatile Compound Generation of Arsenic, Silver and Gold by Tetrahydroborate Reaction for Atomic Absorption Spectrometry
Musil, Stanislav ; Rychlovský, Petr (advisor) ; Kanický, Viktor (referee) ; Spěváčková, Věra (referee)
(EN) The presented dissertation thesis summarizes the results contained in five original research papers that were published in prestigious international scientific journals in the field of analytical chemistry and atomic spectrometry. It is devoted to the method of generation of volatile compounds using a tetrahydroborate reaction and detection in a quartz multiatomizer by atomic absorption spectrometry. The thesis can be divided into two thematic parts - speciation analysis of arsenic based on hydride generation technique with collection and separation in a cryogenic trap and generation of volatile species of transition metals. In the first thematic part pre-reduction of pentavalent inorganic and methylated arsenicals has been studied. A simple setup for on-line pre-reduction employing thioglycolic acid as a fast pre-reductant has been developed, connected with a current hydride generator and applied/verified to oxidation state specific arsenic speciation analysis of human urine samples. In the same method the possibility of drying the gaseous phase from water vapor has been investigated to avoid incidental blocking the cryogenic trap by frozen water and to decrease fluctuations of signal baseline. Pronounced losses of methylated species have been discovered on Nafion tube dryer currently used in...
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Image Registration - Application in ophthalmology and ultrasonography
Harabiš, Vratislav ; Matula,, Petr (referee) ; Zemčík, Pavel (referee) ; Kolář, Radim (advisor)
Image registration is widely used in clinical practice. However image registration and its~evaluation is still challenging especially with regards to new possibilities of various modalities. One of these areas is contrast-enhanced ultrasound imaging. The time-dependent image contrast, low signal-to-noise ratio and specific speckle pattern make preprocessing and image registration difficult. In this thesis a method for registration of images in ultrasound contrast-enhanced sequences is proposed. The method is based on automatic fragmentation into image subsequences in which the images with similar characteristics are registered. The new evaluation method based on comparison of perfusion model is proposed. Registration and evaluation method was tested on a flow phantom and real patient data and compared with a standard methods proposed i literature. The second part of this thesis contains examples of application of image registration in~ophthalmology and proposition for its improvement. In this area the image registration methods are widely used, especially landmark based image registration method. In this thesis methods for landmark detection and its correspondence estimation are proposed.
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Preparation Techniques and Characterization of Electrodes with Nanostructured Surface
Hrdý, Radim ; Trnková, Libuše (referee) ; Janderka,, Pavel (referee) ; Hubálek, Jaromír (advisor)
Nowadays, nanostructures fixed on solid substrates and colloidal nanoparticles permeate through all areas of human life, in area of sensors and detection as well. This dissertation thesis deals with the fabrication of nanostructures on the surface of planar electrodes via self-ordered nanoporous template of aluminum trioxide. The nanofabrication, as one of many possible techniques, is used to increase the active surface area of electrodes by creating unique surface types with specific properties. These electrodes are very perspective in the applications, such as biomolecules electrochemical detection and measurement. The transformation of aluminum layer into non-conductive nanoporous template in the process of anodic oxidation is a fundamental technique employed to obtain the array of nanostructures in this thesis. The fabrication of high quality nanoporous membranes with narrow pore size distribution on various types of metallic multilayers is one of the key experimental parts in this work. Several problems associated with the production of the thin-film systems, including the dissolving the barrier oxide layer, are discussed and solved. Another part of this work deals with the use of nanoporous membrane as a template for the production of metallic nanostructures via electrochemical metal ions deposition directly into the pores. The obtained nanostructures as nanowires, nanorods or nanodots are characterized by the scanning electron microscopy and energy-dispersive or wavelength X-ray spectroscopy. The electrode surface, modified by gold nanostructures suitable for the detection of biomolecules, has been chosen for the electrochemical measurements, due to the gold biocompatibility. The nanostructured electrodes were characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The effect of nanostructured surface geometrical parameters, including the size of the electrochemically active area, on the results of electrochemical measurements has been observed and compared to flat gold electrodes. Two model biomolecules, namely guanine and glutathione, have been chosen for the study of potential application of these nanostructures in biosensors.
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Exploring Brain Network Connectivity through Hemodynamic Modeling
Havlíček, Martin ; Hluštík, Petr (referee) ; Šmídl,, Václav (referee) ; Jan, Jiří (advisor)
Zobrazení funkční magnetickou rezonancí (fMRI) využívající "blood-oxygen-level-dependent" efekt jako indikátor lokální aktivity je velmi užitečnou technikou k identifikaci oblastí mozku, které jsou aktivní během percepce, kognice, akce, ale také během klidového stavu. V poslední době také roste zájem o studium konektivity mezi těmito oblastmi, zejména v klidovém stavu. Tato práce předkládá nový a originální přístup k problému nepřímého vztahu mezi měřenou hemodynamickou odezvou a její příčinou, tj. neuronálním signálem. Zmíněný nepřímý vztah komplikuje odhad efektivní konektivity (kauzálního ovlivnění) mezi různými oblastmi mozku z dat fMRI. Novost prezentovaného přístupu spočívá v použití (zobecněné nelineární) techniky slepé dekonvoluce, což dovoluje odhad endogenních neuronálních signálů (tj. vstupů systému) z naměřených hemodynamických odezev (tj. výstupů systému). To znamená, že metoda umožňuje "data-driven" hodnocení efektivní konektivity na neuronální úrovni i v případě, že jsou měřeny pouze zašumělé hemodynamické odezvy. Řešení tohoto obtížného dekonvolučního (inverzního) problému je dosaženo za použití techniky nelineárního rekurzivního Bayesovského odhadu, který poskytuje společný odhad neznámých stavů a parametrů modelu. Práce je rozdělena do tří hlavních částí. První část navrhuje metodu k řešení výše uvedeného problému. Metoda využívá odmocninové formy nelineárního kubaturního Kalmanova filtru a kubaturního Rauch-Tung-Striebelova vyhlazovače, ovšem rozšířených pro účely řešení tzv. problému společného odhadu, který je definován jako simultánní odhad stavů a parametrů sekvenčním přístupem. Metoda je navržena především pro spojitě-diskrétní systémy a dosahuje přesného a stabilního řešení diskretizace modelu kombinací nelineárního (kubaturního) filtru s metodou lokální linearizace. Tato inverzní metoda je navíc doplněna adaptivním odhadem statistiky šumu měření a šumů procesu (tj. šumů neznámých stavů a parametrů). První část práce je zaměřena na inverzi modelu pouze jednoho časového průběhu; tj. na odhad neuronální aktivity z fMRI signálu. Druhá část generalizuje navrhovaný přístup a aplikuje jej na více časových průběhů za účelem umožnění odhadu parametrů propojení neuronálního modelu interakce; tj. odhadu efektivní konektivity. Tato metoda představuje inovační stochastické pojetí dynamického kauzálního modelování, což ji činí odlišnou od dříve představených přístupů. Druhá část se rovněž zabývá metodami Bayesovského výběru modelu a navrhuje techniku pro detekci irelevantních parametrů propojení za účelem dosažení zlepšeného odhadu parametrů. Konečně třetí část se věnuje ověření navrhovaného přístupu s využitím jak simulovaných tak empirických fMRI dat, a je významných důkazem o velmi uspokojivých výsledcích navrhovaného přístupu.
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Local optical and electrical characteristics of optoelectronic devices
Škarvada, Pavel ; Hrabovský, Miroslav (referee) ; Lazar, Josef (referee) ; Tománek, Pavel (advisor)
Solar energy conversion, miniaturization of semiconductor devices and associated lifetime, reliability and efficiency of devices are the basic premise of this work. This work is focused on the study of optoelectronic devices especially solar cells and its nondestructive diagnostic. Solar cells are advantageous for study mainly because the pn junction is located near the surface and contains a lot of inhomogeneities. It has been difficult until recently to investigate their local physical (electrical and optical) parameters due to the size of inhomogeneities. Behavior of inhomogeneities can be well understood with knowledge of its local properties. Establishment of measurement workplace, that satisfies requirements for measurement of local emission and optically induced current measurement, allows us detection and localization of inhomogeneities with spatial resolution more or less 100 nm. The core of thesis is characterization of imperfection using nondestructive techniques in the macroscopic region but primarily in microscopic region using scanning probe microscopy. Integral parts of the work are characterization techniques for photoelectrical devices, microscopic techniques and data processing. Scanning near-field optical microscope is used for the purpose of microscopic characterization such as topography, local optical, photoelectrical and electrooptical properties of structures in high spatial resolution. Locally induced current technique, current voltage characteristics, emission from reversed bias pn junction measurement including its thermal dependence are used for samples investigation in macroscopical region. It is possible to localize defects and structure inhomogeneity using mentioned techniques. Localised defects are consequently analyzed for composition and measured using electron microscopy. Specific outputs of work are classification of photoelectric devices defects and specification of nondestructive characterization techniques used for defect detection. Experimental characterization techniques are described together with defects measurement procedures. The key output is the catalog of serious defects which was detected. Particular defects of samples are shown including describe of its properties and physical meaning.
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Automatic delineation of ECG signals
Vítek, Martin ; Tyšler, Milan (referee) ; Halámek,, Josef (referee) ; Kozumplík, Jiří (advisor)
This dissertation deals with QRS complex detection and ECG delineation. The theoretical part of the work describes basics of electrocardiography, QRS detection approaches, ECG delineation approaches, the standard CSE database and the wavelet transform theory. The practical part of the work describes designed methods of QRS complex detection and ECG delineation. The designed methods are based on a continuous wavelet transform, appropriate scales, appropriate mother wavelet, cluster analysis and leads transformation. The introduced algorithms were evaluated on the standard CSE database. The obtained results are better, than directly comparable results of other methods and accomplished given database criteria. The robustness of designed algorithms was successfully tested on CSE database signals modified by compression and filtering. The proposed ECG delineation algorithm was successfully used as a tool for evaluation of diagnostic distortion of ECG signals modified by compression.
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METHODS FOR DETECTION AND CLASSIFICATION IN ECG ANALYSIS
Kičmerová, Dina ; Kremláček,, Jan (referee) ; Sovka, Pavel (referee) ; Provazník, Ivo (advisor)
První část práce je zaměřena na měření QT intervalu. QT interval může být použit k hodnocení kardiovaskulárního zdraví pacientů a detekovat potenciální abnormality. QT interval je měřen od začátku QRS komplexu až po konec T vlny. Nicméně, měření konce T vlny je často vysoce subjektivní a jeho verifikace je obtížná. Představujeme dvě metody měření QT intervalu - vlnkovou a šablonovou metodu. Metody byly porovnány mezi sebou a testovány na QT databázi. Druhá část práce je zaměřena na modelování arytmických signálů McSharryho modelem následována klasifikací s použitím umělých neuronových sítí. Metoda používá předzpracování signálů lineární aproximací a shlukování lineárních segmentů pro stanovení počátečních parametrů McSharryho modelu. Byly použity EKG signály standardní MIT/BIH Arrhythmia Databáze. Modelování bylo testováno na celé databázi a svodu MLII (modifikovaný svod II). Všechny signály mohou být modelovány 10 Gaussovými funkcemi bez významného zkreslení. Třetí část práce představuje klasifikaci EKG do dvou tříd. Předčasné komorové kontrakce (PVC) mají vysoký význam při hodnocení a predikci život ohrožujících ventrikulárních arytmií. Představujeme algoritmus pro detekci předčasných komorových kontrakcí s použitím McSharryho modelu a neuronových sítí. Signály modelované 30 Gaussovými parametry byly předloženy na vstup umělé neuronové sítě. Použitý vícevrstvý perceptron dosáhl klasifikační úspěšnosti 93,10% pro předčasné komorové kontrakce (PVC) a 96,43% pro normální stahy.
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The feasibility of different biodosimetric methods for dose estimation in case of radiation accidents.
PAVEZKA, Luboš
A deterioration of the coincidental hazards linked to the use of ionizing radiation is currently observed for four reasons. First, the increasing demand for radiation sources in numerous industrial applications (food sterilization, construction, engineering) leads to an increasing likelihood of loss of the sources or abnormal/unsuitable use and storage. Second, advances in medicine generate new protocols and tools that are more efficient but also much more complex to execute, increasing the risk of accidental overexposure. Third, the possibility of a terrorist attack using radiological or nuclear devices has to be taken into account. Finally, recent events in Fukushima (Japan) highlight the risks of exposure in the case of nuclear power plant accidents. All these issues could lead to the accidental exposure of one to several thousand individuals not wearing dosimeters. Thus, it is essential to be able to assess the exposure level of victims. Nowadays, this evaluation is based on clinical diagnosis (mainly irradiation symptoms and hematological variations) supplemented with biological dosimetry andphysical dose reconstruction. Biological dosimetry is especially important when the personal dosimeter is lacking or when the accidental context is unclear. All this information should help the medical staff to deliver appropriate medical care and to manage the long-term medical follow-up, if required. To fulfil this task, the dose estimates has to be timely, exact and conclusively reached in large-scale disasters. In my bachelor thesis, I have focused on the applicability of the various techniques for different scenarios: small- and large-scale exposes to different levels of a radiation that could manage to the urgent radiation syndrome and exposures with lower doses that do not need direct care, but should be followed for evidence of long-term impacts. The principle of biodozimetry is to utilize changes caused in the individual by ionizing radiation to estimate the dose and, if feasible, to predict or reflect the clinically relevant reaction. Optimally, the changes should be specific for ionizing radiation, and the response should be unaffected by prior medical or physiological variations among subjects, including changes that might be caused by the stress and trauma from a radiation event. There are two basic types of biodozimetry with dissimilar and very often complementary characteristics: those based on changes in biological parameters such as gene activation or chromosomal abnormalities and those based on physical changes in tissues. Factors advised comprise: time interval when the assay is feasible biologically, time for sample preparation and analysis, dose finding limit, ease of use, logistical demands, potential efficiency, point-of-care eligibility, and the ability to support patient diagnosis and treatment within a therapeutically relevant time point. The development of of biodozimetry has been mainly encouraged by the needs after a large-scale accident, where it is essential to have a tool or device to identify those individuals who would profit to be brought into the medical care system.
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The use of physiotheraphy procedures for treating inflammatory rheumatic disease selected from the perspective of patients.
CIHLÁŘOVÁ, Irena
Rheumatology is a part of internal medicine that deals with diseases of musculoskeletal system. It is primarily devoted to diagnosis and treatment of these diseases. Rheumatoid diseases primarily affect joints and muscles, but other organs can also be affected endocrine glands, the nervous system, internal organs such as the kidneys, liver, lungs, human gastrointestinal tract, and skin. The diseases are classified as follows: inflammatory, degenerative, metabolic bone and joint diseases, extra-articular rheumatism, septic arthritis, etc. The causes of these diseases are unknown, but internal and external factors play an important role. They may be infectious, immunogenetic factors and effects of the external environment such as drugs and chemicals. The aim of this work is to map the use of physical procedures in the treatment of inflammatory rheumatic diseases. To do this, the following research questions were formulated: 1. Which are the most commonly used physical methods in the treatment of rheumatic diseases? 2. What effects does the application of physical therapy have on the patient? 3. How does inflammatory rheumatic disease affect the patient's life? 4. Which procedures can the patient apply in the home environment? 5. Are patients satisfied with physical therapy? Qualitative methods were chosen for the research part of this work and a semi-structured interview was used as the technique for data collection. The respondents were asked 28 questions. The research sample consisted of 10 respondents. The respondents were chosen from rheumatologic surgeries in Tábor and Pelhřimov. They consist of 5 respondents with a diagnosis of Bechterew's disease and 5 respondents with a diagnosis of rheumatoid arthritis. The interviews were conducted as previously arranged in the respondents' homes or via email. The results show that in most of the respondents the disease occurred between the ages of twenty and thirty. The first symptom was a painful and swollen joint. They most often use disease modifying drugs, anti-inflammatory drugs, and analgesic drugs for the treatment. Examples of disease modifying drugs include Methotrexate, Sulfasalazine, Aflamil, and Arava. Aulin is among the most commonly used NSA. Enbrel was mentioned by the respondents as a preparation used in biological therapy. Among the regime measures which the respondents take to reduce symptoms, were most often mentioned home workouts, changes of diet, compresses, ointments, and other compensation aids. As regard physical therapy, the respondents were most satisfied with balneotherapy, namely with massages and warm packs. The most used method is magnet. Physical therapy primarily helps to ease pain and relax muscles and stiff joints. Nurses educate patients about drug effects, the changes that are to come in their lives and to which they need to prepare; about the importance of workouts, rehabilitation, and compensatory aids. The quality of the respondents' lives is substantially limited by pain, stiff joints, and severe fatigue. For these reasons, the respondents are unemployed and have to receive a disability pension. In the initial period, the respondents suffered from the feelings of anxiety, helplessness, hopelessness, and depression. The family plays an important role in this context, helping and supporting the respondents. According to the data obtained it can be concluded that physical therapy helps to customers with rheumatoid inflammatory disease to relieve from pain and stiffness in joints. The course of the disease can be influenced by regular workouts that can help ease the symptoms. In some cases, the symptoms disappear for some time. It is very important to appropriately inform customers about their disease, therapy, rehabilitation and the changes they will have to undergo in life. The doctors and nurses deal those problems in the rheumatic clinics and spas. This thesis points to common problems of patients with inflammatory rheumatic diseases.
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