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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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Simulation of ultrasound sequences in contrast mode
Staňková, Jana ; Mézl, Martin (referee) ; Harabiš, Vratislav (advisor)
This bachelor thesis deals with the principle of contrast imaging techniques for ultrasound imaging. In the first part there are described basic principles and characteristics of ultrasound 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 models with a focus on obtaining perfusion parametres and analyzing perfusion curves obtained by measuring the ultrasound contrast agent over time. The second part is devoted to designing a program for generating simulated ultrasound images and description of the simulation of 2D ultrasound tomograms.
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Design of Portable Ultrasound Device
Sedláková, Jana ; Buganská, Tamara (referee) ; Křenek, Ladislav (advisor)
The goal of bachelor thesis is proposing design of portable ultrasound device, which could be a complement of existing range of this type with respecting all technical and aesthetic requirements. This device should be convenient mainly for doctor’s necessities and for giving brief information about foetus of pregnant women
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Virtual instrument for experimental ultrasonic measurement
Dufek, Ladislav ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This bachelor’s thesis is about usage the virtual instrument created in LabVIEW environment for measurement of ultrasonic transducers and for resulting signal scanning. It briefly describes the basics of ultra acoustic and the principles of piezoelectric transducers. Then problematic of generation and scanning signals using cards National Instruments NI-PCI 5401 and NI-PCI 5102 are explained. Subsequently an instrument is designed. This instrument is used for experimental measurement at 4 pcs engineering samples of ultrasound transducers, is painted the frequency response characteristic and determines frequency of resonance.
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Cheap device for non-invasive detection of blood flow
Mívalt, Filip ; Majzner, Jiří (referee) ; Sedlák, Petr (advisor)
Blood flow measurement by Doppler effect is widely used technique for the assessment of blood vessels condition. Stenosis, aneurysm and blood insufficiency might be revealed by this method. In recent years, measurement devices based on Doppler effect haves been introduced also in veterinary medicine. For example, peripheral blood pressure of a cat might be observed at tail or paw. This thesis deals with the design of blood flow Doppler detector prototype and its implementation to fully operational instrument. Proposed device is uses a low-cost doppler probe. Blood flow detection is based on the analysis of Doppler probe output signal discrete power spectrum. The frequency spectrum is determined from digitized preprocessed analog signal. This thesis should illustrate the possibility of usage of Arduino platform and cheap ultrasound vascular probe as alternative for expensive Doppler devices.
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