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Numerical model of ultrasonic oil level sensor
Chutný, Pavel ; Bílek, Michal (referee) ; Vyroubal, Petr (advisor)
This master’s thesis verifies physical principle of ultrasound in fluids by numerical model. At first, ultrasound study is ment. In second theoretic part, diferent kind of motor oils are described. Next, equations for numerical simulation are presented. In practical part, numerical model of level sensor is examined in well-knowed fluids (water, air). Results of laboratory measurement on topic of ultrasound velocity in oil dependent on temperature are aplicated on numerical model of sensor and optimalized.
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Ultrasound image processing
Pokorný, Vojtěch ; Harabiš, Vratislav (referee) ; Mézl, Martin (advisor)
Ultrasound is an important imaging modality used in medicine. This bachelor’s thesis includes theory regarding physical characteristics of ultrasonic waves, a brief overview of the historical development of ultrasound as an imaging modality in medicine, biophysics of spreading and biological effects of ultrasound waves on tissues and types of display final images. Next part of the thesis describes diagnostic ultrasound device, including the most common used types of ultrasound probes. This part is followed by description of animal Vevo 2100 ultrasound system from which the acquired data are processed further. Processing includes the loading, display and for DICOM files saving too. At various file formats DICOM standard comparison is done. The last chapter deals with the filtration of characteristic noise for ultrasound images called speckle.
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Distance and position determination using ultrasound
Bartoš, Dalibor ; Šteffan, Pavel (referee) ; Hejátková, Edita (advisor)
This thesis describes distance measurement using ultrasound and its application in determining position of an object. First part of this thesis describes principles of ultrasound wave propagation, piezoelectric transducers, basics of both triangulation and trilateration and different kinds of park assist systems. The second part contains description of algorithms designed to determine position of two objects at the same time. Last part of the thesis describes implementation of created algorithms into software and also modules used in the test measurement.
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Analysis of AVG signal
Matušek, Adam ; Kozumplík, Jiří (referee) ; Rozman, Jiří (advisor)
Bachelor´s thesis deals with analysis of AVG signal (arteriovelocitogram). Measured data predicate about speed and caracteristic of blood flow in human arteria. Signal is taken by ultrasound mesure. We use reflection of mechanic wave from moving objets followed by a chase of frequence. This fenomen is called Doppler effect. When we know analysis results we can diagnostic the existence and phase of ischemic desease. The clasification of the dates was made by methods of cluster analysis. Statistic algorithm was realised in programing world MATLAB.
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Simulation of ultrasound sequences in contrast mode
Staňková, Jana ; Hesko, Branislav (referee) ; Harabiš, Vratislav (advisor)
This bachelor thesis deals with the principle of contrast imaging techniques for ultra-sound imaging. In the first part there are described basic principles and characteristics of ul-trasound waves for the understanding. It is also focused on ultrasound contrast agents used in contrast enhanced ultrasound imaging. The important part is the description of perfusion mo-dels with a focus obtain perfusion parametres and analyze perfusion curves obtained by mea-suring the ultrasound contrast agent over time. The second part is devoted to designing a pro-gram for generating simulated ultrasound images and description of the simulation of 2D ul-trasound tomograms.
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Measurement and analysis of the blood flow in peripheral vessels by ultrasound Doppler methods
Lepš, Milan ; Sedlář, Martin (referee) ; Vlk, Daniel (advisor)
Nowadays, the Doppler ultrasonography is an essential part in medicine. With it, we can observe acoustic showoff some tissue associated with Doppler measurement of blood flow parameters. It is still using Doppler devices with a continuous signal which are although structurally and technically simpler, but they are suitable for measuring the speed and volume of blood flow in peripheral blood vessels of the upper and lower limbs. There are calculated physiological parameters from the flow curves that are clinically used for assessing the state of blood supply to the body part. We can determine many values from the flow curves, like peripheral resistance, blood flow in systole and diastole, medium speed, etc. Study group of people are male and female students from 18 to 20 years. Doppler measurements have been performed before physical exercise and after physical exercise.
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ASSESSMENT OF REINFORCED CONCRETE STRUCTURES EXPOSED TO ELEVATED TEMPERATURES
Rozsypalová, Iva ; Kolář,, Karel (referee) ; Vítek,, Jan (referee) ; Daněk, Petr (advisor)
Doctoral thesis is focused on the assessment of concrete structures after fire exposure and extends the knowledge in view of the main aims of the research defined in the objectives of his work. Thanks to the performed fire tests of full-scale concrete specimens, material characteristics corresponding to actual fire load have been assessed for different temperature levels. Resulting from presented research, main steps of assessment procedure have been recommended for both destructive and non-destructive tests of concrete after exposure to fire. Furthermore, behaviour of FRP reinforcement at elevated temperatures have been investigated. Aiming to determine the effects of fire exposure on reinforced concrete structures, experimental program have been defined and performed, including concrete beams reinforced with either steel, or composite reinforcement with glass or carbon fibres and subjected to experimentally simulated fire load. After cooling, bending test have been executed. Above mentioned experimental program was further complemented by extensive numerical analysis. Finally, presented work provides guidelines regarding further investigations required in this field of research.
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Speckle noise suppression
Kuchař, Otakar ; Hesko, Branislav (referee) ; Mézl, Martin (advisor)
Master thesis deals with the study of ultrasound. The first part of this work is devoted to basic physical principles, imaging modes, ultrasound probes, biological effects and the last part is associated with the artifact associated with ultrasound waves. In the next part the specific noise called speckle noise is detaily discussed. The description includes both a mathematical and a statistical view. Several methods are described to eliminate this noise. In the practical part the described methods are realized and compared based on objective and subjective evaluation.
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Power measurement in ultrasound fields
Škůrek, Pavel ; Čížek, Martin (referee) ; Rozman, Jiří (advisor)
This work is focused on the developement of a sensor, which enables to measure the ultrasonic power by heat effect of the mechanical Wales. The princip of two basic kinds of thermoacoustic sensor is descibed here – one level and two level sensor. This work also contains a proposition of these sensors with description of each parts and a trial to find suitable absorber. Achieved results, which support the function of the sensors are presented here by form of graphs and tables. Measuring by thermoacoustic sensors is confronted here with measuring of ultrasonic by hydrophone, which is used as reference measuring.
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