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Percutanous electrogastrography, principle and posibilities of clinical application in abdominal surgery
Fraško, Roman ; Krška, Zdeněk (advisor) ; Maršálek, Petr (referee) ; Szárszoi, Ondrej (referee)
Author of this dissertation presentation discuss in the begining definition and historical consequences of origin and consecutive evolution of the method of percutaneous electrogastrography. Intimately is described physiology, anatomy, embryology and function of gastrointestinal tract with special interest on construction and function of the stomach. Next to this author analyses current knowledge about location and function of the gastric pace setter. The technique of used perctutaneous electrogastrography equipmentt is described. In the second part results of original studies monitoring restoration of peristalsis in perioperative period at patients after open and laparoscopic cholecystectomy and laparoscopic non-adjustable gastric banding are discussed. Furthermore results of EGG measurement of patients with mechanic, vascular and paralytic intestinal obstruction are presented in correlation with plasma levels of interleukin 1β, interleukin-6, procalcitonin and C-reactive protein. Key words: Percutanous electrogastrography, laparoscopic cholecystectomy, laparoscopic gastric bandage, inflammatory mediators, intestinal obstruction.
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Sound Processing in an Emulator of Cochlear Implant
Tóth, Peter ; Maršálek, Petr (advisor) ; Hric, Jan (referee)
The time accuracy of the auditory neuronal pathway in its sound localization branch is high, compared to other sensory systems. The time differences in the sound arrival between the left and right ear are distinguished by the neural circuit in this branch. The accuracy achieved here is in the order of tens of microseconds. This phenomenon has not yet been definitively clarified. In this master thesis, a model of a neuron central to this neural circuit is presented. This neuron is called binaural (neuron of the two ears) and is located in the medial superior olive (MSO) neural nucleus. The properties of the MSO neuron are described. Specifically, the neuron acts as a coincidence detector, and this is necessary for the circuit functioning. Main result of the thesis is the theory explaining how the function of the coincidence detector can be described based on the interaction of the post-synaptic potentials on the spike-response model neuron. Generality and implications for the auditory pathway are then discussed.
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Models of binaural hearing
Drápal, Marek ; Maršálek, Petr (advisor) ; Wünsch, Zdeněk (referee) ; Lánský, Petr (referee)
In this work is presented stochastic model of binaural hearing in context of another alternative models. According to latest experimental data on mammals, inhibition plays a role in interaural time difference recognition, which is a key for low frequency sound source localization. The outputs of experiments may lead to the conclusion that the binaural hearing works differently in mammals compared to birds. Nowadays there are a few theoretical works addressing this new phenomena, but all of them are relaying on a very precise inhibition timing, which was never proved as physiologically valid. On the other hand, models described in this work are based on the fact, that every neuron has a random delay when reacting to an excitation. If this time jitter is taken into account and combined with inhibitory signal, delay in the neuronal circuit and coincidence detection, then the output firing rate corresponds to the azimuth of the sound source. In this work it is shown, that such a neuronal circuits are giving the same output results compared to experimental data. The models are supported by analytical computations and numerical simulations including simulation of cochlear implant.
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Manikin of head for tests of spatial sound localization
Slanička, Radek ; Maršálek, Petr (advisor) ; Husník, Libor (referee)
We designed a custom made manikin head for acoustical studies of spatial hearing. Its shape and dimensions mostly follow the telecommunication norms for headset testing. The differences from the norms are given by its purpose in simulations of acoustic environments outside and inside head. These simulations will be used for studies of normal and impaired binaural hearing. The head is manufactured from a composite material (artificial wood). The cavities inside are fitted with microphones and loudspeaker and enable measurements of sound propagation inside and outside of the head. We discuss a manufacturing procedure in detail together with step-by-step production instructions.
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Using Artificial Neural Networks to Study Non-Linear Properties of Single Neurons in the Auditory Cortex
Hromádka, Tomáš ; Kůrková, Věra (advisor) ; Maršálek, Petr (referee)
Neurony v naších mozcích převádějí informace o okolním světě do elektrických akčních potenciálů. Klíčem k pochopení funkce neuronů, a poté neuronových sítí a mozku, je vědět, které části okolního světa jsou zastoupeny v aktivitě neuronů, a jakým způsobem je tato informace kódována. Tradiční metodou zkoumání funkce neuronu je zaznamenání odpovědi neuronu na podněty různé složitosti a následně snaha vysvětlit přenosovou funkci neuronu pomocí lineárního modelu. Většina neuronů však obsahuje nelineární přenosovou funkci. V této práci jsme použili umělé neuronové sítě ke studiu nelineárních přenosových funkcí neuronů sluchové kůry. Zaznamenali jsme podprahovou aktivitu neuronů jako odpověď na stimulaci přirozenými zvuky a poté jsme použili neuronové sítě v roli nelineárních aproximátorů k odhadu přenosových funkcí neuronů. Umělé neuronové sítě úspěšně aproximovali přenosové funkce a v průměru odhadli funkce neuronů nejméně stejně dobře jako lineární modely. Powered by TCPDF (www.tcpdf.org)
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Design of leg for crash test dummy
Maršálek, Petr ; Semela, Marek (referee) ; Bilík, Martin (advisor)
This thesis is devoted to the design model of the lower limbs crash test dummies. It describes how the dummy developed historically, what are currently available for crash tests, what they are made and what their future will be. The main motive of the work is to design a model of lower limb for crash tests, with emphasis on the human anatomy. The work is characterized by how the figurine is produced using the form from material Thermolyne Clear, wood as a substitute human bones and the agar substitutes such as human muscle.
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ICT Selection
Hanyk, Tomáš ; Maršálek, Petr (referee) ; Koch, Miloš (advisor)
This bachelor thesis deals with the selection and implementation of information systems for businesses PORTABELL limited liability. There are described theory,methods, and analysis technologies that are closely related of the information system. Based on the analysis of the requirements the company is selected, the corresponding information system which is designed draft of implementation process.
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