61 |
Nové ultrazvukové markery aneuploidií v prvém trimestru gravidity / New Aneuploidy Ultrasound Markers in First Trimester of PregnancyBřešťák, Miroslav January 2015 (has links)
Prenatal diagnostics is headed in several directions - towards visualization of fetuses and biochemical, cytogenetic and molecular genetic diagnostics in laboratories. Whereas visualization of fetuses does not a priori represent any direct risk for pregnancy and does not increase the number of potential pregnancy complications, this is not always the case with the laboratory testing. There are known risks connected with invasive methods of prenatal diagnostics. The number of potential unintentional pregnancy complications and losses as well as the technical and economic aspects of invasive prenatal diagnostics lead to attempts of identifying ways of detecting any potentially affected individuals by screening methods, thus minimizing the undesirable impact of invasive diagnostics on the pregnant population. The more precise the selective criteria, the lesser the number of pregnant women exposed to invasive exams. Another way of decreasing the number of unintentional complications in relation to invasive diagnostics is to simplify and improve the fetal samples harvesting methods during pregnancy. The work primarily focused on two areas: Determination of the relation between fraction shortening of the left and right ventricles and a fetal chromosomal complement, and verification of reliability of a new method...
|
62 |
Ultrazvukový indikátor toku krve / Ultrasound blood flow detectorKameníček, Robert January 2010 (has links)
My master’s thesis deals with methods of measuring the ultrasonic blood flow blood vessel with a detailed focus on Doppler ultrasound systems, which find application in the diagnosis of superficial vascular and obstetrics. The thesis is described a proposal indicating polydirectional Doppler system with a continuous carrier wave frequency of 4 MHz, the intensity of ultrasound 100 mW/cm2 and diameter D-shaped transducers 8 mm. As a result, the indicator will be able to measure blood flow velocity in the range of 5-40 cm/s, which appears to 3.5 digit display. After describing important theoretical assumptions, the work pays block diagram indicator. Furthermore, it examines the various functional blocks on the requirements imposed on them. It looks at the options of each functional block, and finally describes the implementation of the selected option and including peripheral solutions. Great attention is paid to the power of the indicator, where the power supply will be used 9 V battery. Create a symmetric voltage for operate amplifier and other auxiliary voltage will procure DC/DC converters. In conclusion, the work is located around the perimeter solutions indicator. The following draft for the production of double-sided PCB, its installation and a list of elements. The outcome of the thesis is complete documentation for the implementation of an indicator of blood flow, which allows us to obtain information on throughput vessels, especially the lower and upper limbs.
|
63 |
Počítačová analýza ultrazvukových obrazů uzlů ve štítné žláze se zaměřením na jejich sonografické vlastnosti a cytologické nálezy. / Computer analysis of ultrasound images of thyroid nodules, focusing on their sonographic features and cytological findings.Procházka, Antonín January 2019 (has links)
Ultrasound imaging is one of the fundamental examinations of thyroid nodules, determining whether a patient undergoes a cytological examination, which is essential for the decision on a possible thyroid surgery. Unfortunately, the cytological examination has limited specificity and potential surgery carries risks. Therefore, other diagnostic methods are being sought with hope that they will be able to bring more certainty into diagnostics. One of the new methods is computer-aided diagnosis (CAD), which exhibits promising results using image analysis and machine learning. In this study, we present two somewhat similar, yet different, CAD approaches. The first approach is based on analysing entire nodules using a Segmentation Based Fractal Texture Analysis (SFTA) algorithm that splits the image into individual grayscale bands. Using this approach, we have achieved an accuracy of 92.4% using random forests (RF) and 95% using support vector machines (SVM) on a data set of 40 images evaluated by the cross-validation method. The second CAD approach is also based on the method of multiple image thresholding, but the difference is, that a larger number of predictors describing the binary texture are extracted from the individual grayscale bands. Furthermore, the analysis did not take place on whole nodules, but on...
|
64 |
Aktivace svalů břišní stěny a svalů zad při cvičení s trakčním a kompresním zatížením / Activation of abdominal wall and back muscles during exercise with traction and compression loadsJordáková, Adela January 2018 (has links)
We used RUSI (rehabilitative ultrasound imaging) for measurement of abdominal and back muscle in different loading modes. Methods: We used diagnostic ultrasonography imaging for taking linear measurement of trunk muscles. We measured anterioposterior (AP) dimensions of lateral abdominal wall muscles- m. OE, m.OI, m.TrA and cross-section area (CSA) of lumbar m. multifidus. We compared two groups of sports-floorball players and sportsman using climbing and hanging (climbers, aerialists). We measured positions with compressive force (kneeling on all four with lifted knees) and with traction load (hang with upper limbs with flexion of lower limbs-with leg support and without). Study is made on 50 volunteers. Results: The pattern of thickness of abdominal muscles is same in all positions in both groups. The lowest is always AP thickness of m. TrA, wider is m. OE and the widest always m. OI. The resting thickness are in both groups almost in all cases the lowest. AP thickness in m. TrA in floorball players is only exception, there is lowest in hang without legs support. In all other case sis resting position always lowest. For m. OE are results same for both climbers and floorball players-the lowest thickness is in hang with legs support (floorball players 0,84 cm, climbers 0,87), greater activationis...
|
65 |
Stavební průzkum a hodnocení stavu konstrukce / Building survey and evaluating the state of constructionBalash, Alan January 2019 (has links)
This diploma thesis is focused on building survey and evaluating of the state of the three-storey industrial hall. The diploma thesis consists of two parts - theoretical and practical. In the theoretical part is described a common procedure for evaluation of the state of existing structures, methods used in diagnostics (selected ones - more detailed), advantages and disadvantages of methods. In the practical part is carried out construction and technical survey of the industrial hall, the concrete strength evaluation and verification of presence and type of reinforcement. At the end of the work - evaluation of objects.
|
66 |
Ultrazvukový měřič rychlosti toku krve / Ultrasonic blood flow meterPavlík, Dušan January 2011 (has links)
This thesis deals with ultrasound blood flow meter design with emphasis on practical implementation of such device. This medical device is used in ultrasound diagnostic, especially for measuring direction and velocity of blood flow in superficial vessels. This thesis contains consecutive design including description of individual function blocks. Documents for making double-sided printed circuit are included as well.
|
67 |
Modelování nelineárních jevů v ultrazvukových polích / Model nonlinear effect in ultrasound fieldsKulík, Tomáš January 2012 (has links)
The main topic of this diploma thesis is the modeling of nonlinear effects in ultrasonic fields. The work deals with application of finite difference method (FDTD) on the Westervelt equation and the subsequent creation of the model of ultrasonic fields in MATLAB. This thesis also includes theoretical analysis of ultra-acoustic and technical aspects of diagnostic ultrasonography. In addition, this document includes verification of theoretical assumptions by using created model.
|
68 |
Metody potlačení strukturního šumu typu spekle / Speckle noise suppression methods in ultrasound imagesTvarůžek, Marek January 2013 (has links)
This diploma thesis deals with the methods of despeckling in ultrasound images. Ultrasound imaging and related artifacts are described in more details. Ultrasound imaging has its pros and cons, where speckle noise is a disadvantage to be solved. Models of origin of this specific noise are referred too. Practical part of this thesis aims on filtering speckled images by basic and advanced filtering methods as are linear filtering, median filtering, application of Frost filter, QGDCT, geometric filtering, anisotropic diffusion filtering and filtering based on wavelet transformation. Results are compared on the basis of objective criteria.
|
69 |
Fantomy pro oftalmologický ultrazvukový systém / Phantoms for ultrasound system in ophthalmologyFabík, Vojtěch January 2013 (has links)
In our work we have studied the ultrasonic imaging systems and their use in ophthalmology, especially with the device Nidek 4000. We described ophthalmological examination methods. In addition, we are using the simulation program Field II. It simulated eye phantom and created his B-scan and biometry, where we compared the effects of different central frequency ultrasonic probes and different speeds of sound in the resulting values. We also created phantoms using agarose gel and materials of different properties. On phantoms, we studied the effect of the velocity of ultrasound in measurement results, effect of the concentration of the agarose gel to the velocity of sound. And we created phantoms simulating the human eye. Measurement protocol was created for use in teaching.
|
70 |
Měření vlastností oftalmologického ultrazvukového systému / Properties measurement of ultrasound system in ophthalmologyGrebíková, Lucie January 2014 (has links)
The thesis deals with physical principles of ultrasound with following specialization on ophtalmic ultrasound system Nidek Echoscan 4000 and its properties. And also it deals with description of investigative techniques in ophthalmology (A-mode, B-mode, biometry and pachymetry). Next, they was suggested procedures of measurement and that is spatial resolution (axial and lateral spatial resolution) and propagation speed of ultrasound depending on the temperature. Then these properties was tested on laboratory phantoms of eye – ETETECH LTD. and Multipurpose Ultrasound Phantom but on created phantoms of eye too, which will be made from agarose gel with build-in materail (fishing line, plastic film, plastic bag and rubber). At the end, measured values was processed in the generated program.
|
Page generated in 0.0519 seconds