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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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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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Virtual environments as a tool to study human navigation
Hejtmánek, Lukáš ; Vlček, Kamil (advisor) ; Maršálek, Petr (referee) ; Brom, Cyril (referee)
Navigation is one of the most common forms of cognitive processing, which is natural for all animal species. But the neuroscientific inquiry into navigation in human subjects has been hindered by the requirements of monitoring methods, which usually require subjects to be com- pletely still. Virtual environments allow scientists to study navigation even while the subject remains unmoving, and offer other benefits such as full control over the experimental procedures or precise behavioral recordings. This thesis offers a basic overview of the biology of navigation and presents why navigation is an interesting cognitive process to investigate. It then presents virtual environments, explores how they can help neuroscientists to study navigation and outlines their limitations. Lastly, the literary review tries to address the question if navigation in virtual environments is comparable to navigation in the real world. The empirical part presents five original studies of human navigation and virtual environ- ments. These studies focus on differences of real world and virtual navigation, investigate neural pathways and brain regions involved in spatial processing, and offer examples of how virtual environments can help conduct studies otherwise impossible to do in the real world. One study provides an...
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Role of Islet1, BDNF and nanoparticles in development, function and regeneration of the auditory system
Chumak, Tetyana ; Syka, Josef (advisor) ; Druga, Rastislav (referee) ; Maršálek, Petr (referee)
Detailed knowledge of the role that particular genes and factors play during the development and in the normal function of the auditory system is necessary to develop successful regenerative inner ear therapies. Islet1 transcription factor and brain derived neurothrophic factor (BDNF) have great potential to play a role in regenerative inner ear therapy as both have been shown to be sufficient for self-repair regeneration in cochlea in animal studies. In this study we looked at the roles these two factors play in the development and function of the auditory system. In the transgenic mice used in the study, overexpression of Isl1 affected cell specification during embryonic development, leading to enlargement of the cochleovestibular ganglion and accelerated nerve fiber extension and branching in mutant embryos. The hearing of young transgenic mice was not affected. However, it started to decline in 1-month-old animals. This early onset of age-related hearing loss was found to be a consequence of the neurodegeneration of the olivocochlear system caused by Pax2-driven Isl1 misexpression in the hindbrain. Our data provide the first evidence that the alternation of the olivocochlear system efferent system accelerates the age-related functional decline of hearing without the loss of OHCs. The functional role of...
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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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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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