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Biomechanical Studies of Facial Bone
Valášek, Jiří ; Janíček, Přemysl (referee) ; Horyl, Petr (referee) ; Florian, Zdeněk (advisor)
Presented work deals with Biomechanical study of the facial skeleton. This work is focused on the fixation of the mandible after removal of a tumor from affected bone tissue. The aim of the work is to perform biomechanical study of the facial skeleton with subsequent detailed stress strain analysis of two mandible implants designed and manufactured for specific patients. The geometry model of mandible used for design of mandible implants and used for computational modelling has been obtained on the basis of CT data of two patients. A Theoretical-Clinical sub-study that deals with the comparison the CT data processing which is necessary for creating the model of geometry is a part of the thesis. Two models of mandible with applied mandible implant have been created for two specific patients with tumorous mandible bone tissue. Stress strain analysis has been performed for these two models. Results of the stress strain analysis of two models of mandibles with mandible implants are presented in the final chapters of the thesis. Findings of the biomechanical study have been published and applied in clinical practice.
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Development of Imaging Methods and its Importance to Biomechanics
Sedláček, Tomáš ; Houfek, Martin (referee) ; Florian, Zdeněk (advisor)
The main objective of this bachelor thesis is to collect all available literature, from which can reader obtain basic knowledge of imaging methods. The methods are divided by its origin into four categories: x-rays, magnetic resonance, ultrasound and nuclear medicine. Each of them is described from the historical, physics and technological view. At the end the importance of each method to medicine and biomechanics is summarized.
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Strain Stress Study of Burch-Schneider Split
Řehák, Kamil ; Horyl, Petr (referee) ; Janíček, Přemysl (referee) ; Florian, Zdeněk (advisor)
This thesis deals with problems of the hip endoprosthetics area, namely total endoprosthesis (TEP) with Burch-Schneider (BS) split, in which there are many problems in clinical practice. The hip joint load depends on the patient weight and the performed activity. Sedentary job, little exercise, a lot of stress or poor eating habits and overweight associated with it affect negatively hip joint. Increasing hip joint wear and its pain in movement is necessary in several cases to be solved by a surgical procedure in which TEP is applied. When selecting and subsequently applying individual TEP, it is important to pay attention to creating conditions which will allow good fixation. In case of worse mechanical properties of bone tissue, it is very problematic to ensure stability of the implant. Based on several classifications which assess the degree of hip joint damage, it is possible to select a suitable TEP. The BS split, on which this work is focused, is dominantly used in cases of large defects in the acetabulum area. The use of this cage allows to bridgelarge defects and create a new centre of rotation of the hip. Knowledge of the mechanical properties of hip bone tissue can significantly affect the prediction of BS split damage. For this purpose, it was necessary to perform a biomechanical study, which is focused on the influence of worse mechanical properties of bone tissue on BS split failure. The computational modelling using finite element method implemented in the ANSY S software was used for the solution, which enables to solve the mechanical interaction between bone tissue and TEP with BS split. Due to the absence of bone tissue data before application of TEP with BS split, the variants before application of TEP and after application of resurfacing and standard TEP were solved. All variants were solved with the material properties of bone tissue that were determined based on CT images. In addition, all variants were solved for the case of degraded mechanical properties. Based on the numerical simulations results and the Mechanostat hypothesis, a bone tissue analysis of the hip joint was performed before and after application of TEP and TEP with BS split. The results show the influence of the computational model level, which considers the distribution of bone tissue through the inhomogeneous model of the material. Therefore, the degraded mechanical properties have a major impact on the stability and strain of the BS split, particularly in the cranial part of the acetabulum.
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Detekce příjmu a účinku herbicidů s využitím zobrazovací fluorescence chlorofylu, UV stínění fluorescence chlorofylu a modro-zelené fluorescence
Otáhalík, David
Abstract The diploma thesis is devoted to the problem of detecting the uptake and effect of herbicides using non-destructive methods of chlorophyll fluorescence imaging, UV shielding of chlorophyll fluorescence and blue-green fluorescence on model species of weed plants or plants simulating weed species (cornflower, white mustard) and model species of field crops (spring barley, field peas). Chlorophyll, flavonol, anthocyanin and NBI index were also used for detection, which were measured pointwise. The measurement of the methods took place on the 3rd and 8th day after the application of herbicides. It is clear from the obtained results that the methods used differ in their sensitivity to the action of herbicides with different mechanisms of action, but that their sensitivity also changes over time after application. At the same time, a significant interaction with the species according to its sensitivity to the given herbicide is also evident, but at the same time, some methods have recorded responses to the action of the herbicide even in cases of tolerance to the given herbicide, which may be caused by inducing defensive reactions in the plant, such as the accumulation of flavonols or anthocyanins. 3 days after the application of herbicides, the most statistically significant responses to the action of herbicides were found in the anthocyanin and chlorophyll index, the UV shielding of chlorophyll fluorescence and the current quantum yield of photosystem II (ΦPSII) parameter. On the other hand, the least evident reactions to the action of herbicides were found for the non-photochemical quenching parameter (NPQ) and the flavonol index. 8 days after the application of herbicides, the most statistically significant reactions were found for the blue-green fluorescence index, the chlorophyll index and the ΦPSII parameter. At least for the NPQ parameter and the flavonol index. The chlorophyll imaging parameter ΦPSII, the chlorophyll index and the blue-green fluorescence index, which were measured only on the 8th day after herbicide application, generally achieved the most statistically significant detections of herbicide intake and effect. The methods used thus demonstrate high potential. Detection methods have a high potential in assessing the intake and effect of herbicides, but it is necessary to consider the duration of herbicide action, the sensitivity of the species and possibly also the growth phase during application for own interpretation of the results.
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Detekce napadení ječmene listovými chorobami pomocí infračerveného termálního zobrazování, zobazovací fluorescence chlorofylu, UV-stínění fluorescence chlorofylu a hyperspekrálního zobrazování
Holzmannová, Kateřina
The aim of the thesis was, in the theoretical part, to summarize basic information about barley, its use and the leaf diseases that occur most often on barley, and also to summarize the basics of imaging methods potentially useful for the detection of diseases on plant leaves, namely chlorophyll fluorescence imaging, chlorophyll fluorescence UV shielding , hyperspectral imaging and infrared thermal imaging. The aim of the work was to evaluate the potential of individual sensor methods from the point of view of their ability to detect the resistance of spring barley genotypes to powdery mildew based on the experiment carried out with the inoculation of spring barley with grass powdery mildew (Blumeria graminis f. sp. hordei). In the practical part, selected sensor methods are compared within the experiment with 6 lines of spring barley (line of the Pallas variety) differing only in the presence of different genes for resistance to powdery mildew. These lines were chosen to represent a wide range of reaction types in response to infection with avirulent powdery mildew pathotypes, as reaction type can be reflected in the response measured using these indirect methods. Based on the correlation analysis performed for individual parameters measured using tested indirect sensor methods with the values of the light-saturated CO2 assimilation rate, it was possible to state that within each group of methods there is a parameter showing a high ability to predict the plant's response and thus resistance to powdery mildew. It is a chlorophyll index, based on the principle of measuring the infrared and red transmittance of the leaf, the difference between the leaf temperature and the air temperature determined using a thermal camera, the fluorescence decrease ratio - vitality index (Rfd), and finally also the ZM spectral index. In addition to the temperature difference, the values of the Pearson correlation coefficient reach the level of 0.74, which means that it is a highly evident relationship, and the adjusted R2 values are above 0.55, which means that the reliability of the prediction is higher than 55%.
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Detekce houbových chorob ječmene pomocí zobrazovací fluorescence a termálního zobrazování
Holzmannová, Kateřina
The main goal of this work was to perform a literature review of imaging methods for the detection of spring barley diseases, their advantages and disadvantages and to conduct an experiment on spring barley samples with different levels of fungal disease infection to compare disease detection using chlorophyll fluorescence imaging, UV fluorescence imaging and hyperspectral imaging in VNIR and NIR spectral ranges. The originally planned measurements on more diseases were performed due to governmental travel restrictions related to the coronavirus pandemic only for Pyrenophora teres barley infection. The achieved results show that all three methods have the potential for use in the field of early and non-invasive detection of P. teres infection, either for the purpose of aerial monitoring or in the phenotyping of resistance to P. teres. The best correlation to leaf infection was achieved with the parameter actual quantum yield of photosystem II (ΦPSII). This parameter shows a high linearity of relationship to P. teres infection, which gives the assumption of reliable detection in the whole infection range. With regard to the need for measurements from the proximity and also due to possible effect of changes in the intensity of solar radiation, this is rather a parameter applicable for plant phenotyping than for the monitoring of large areas. Very good results in the detection of P. teres infestation were also obtained using the UV fluorescence screening index. UV fluorescence screening also shows a very close relationship to the level of P. teres infection, but of a non-linear nature, where the UV fluorescence shielding index increases sharply with under a low level of infection and is less affected at higher level of infection. This means a higher sensitivity of the method to a small level of infection and may therefore have an advantage especially in the early detection of infection. The UV screening index also have considerable potential for the analysis of the disease spatial distribution at the leaf level, where UV shielding increases in areas around the infestation site but decreases significantly at the infestation site itself. In contrast, hyperspectral reflectance represents considerable potential for monitoring of large areas, because it can be evaluated not only from proximity but also from a drones, aircrafts or satellites. The highest correlation and linearity of relationship between P. teres infection was achieved for the index integrating the wider reflectance range 650-725 nm ANMB650-725. However, good results of estimating the level of infection were also achieved with simple vegetation indices such as NDVI and EVI. For the early detection of P. teres infection, the ARI index based on the anthocyanin absorption band, showing a sharp change in low infection level, seems to be the most suitable. This index also shows very good results of evaluating the spatial distribution of P.teres infection on the leaf, with ARI rising at the site of infection. The best results of the evaluating the spatial distribution of infection was demonstrated by the simple ratio of reflectances in the red and green band (RGR), which, however, shows less close relationship to the total P. teres on the whole leaf. Overall, it can be stated that all three methods have the potential to be used for monitoring of P. teres infection and for phenotyping of resistance to P. teres. For the selection of method, rather the key technical requirements e.g. if the total leaf infection is measured or the distribution of the leaf infection is evaluated, from what distance the measurement can be performed and what is the range of measured areas, and also whether it is necessary to detect low level of infection with high sensitivity at the onset of infection or it is more important to ensure a reliable estimate of the infection in the whole range.
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The biological significance of changes in the vascular wall and atherosclerotic plaque for the development of atherosclerotic disease of the coronary arteries
Horváth, Martin ; Hájek, Petr (advisor) ; Poledne, Rudolf (referee) ; Kovárník, Tomáš (referee)
Acute complications of atherosclerosis are typically caused by arterial occlusion due to acute thrombosis forming over a ruptured vulnerable atherosclerotic plaque (VP). Early identification of such VP prior to their rupture could help prevent these events. At the same time, methods for assessing cardiovascular risk are focused on measures at the population level and are not sensitive and specific enough to assess the risk of individual patients. We therefore focused on the possibilities of in vivo detection of VP using biomarkers and invasive imaging methods. First, we focused on the detection of microRNAs (miRs), which have been investigated in recent years as promising biomarkers for a number of diseases, including atherosclerosis. We determined miR levels using quantitative polymerase chain reaction in peripheral venous blood samples from patients in very early phase of ST-elevation myocardial infarction (STEMI), which served as the closest clinical model of acute VP rupture. The results led to the identification of two miRs (miR-331 and miR-151-3p) that were deregulated in STEMI and could be biomarkers of VP. In the next part of the research, we dealt with the possibilities of invasive imaging of VP using intravascular ultrasound and near- infrared spectroscopy (IVUS and NIRS). We confirmed...
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The role of the radiographer in gastroenterology
VOSEJPKA, Roman
This bachelor thesis focuses on radiological imaging methods that are used in gastroenterological examinations. In radiology, machines keep developing, improving and they become an inherent part of practically all branches of medicine. They are being applied in both, therapy as well as illness diagnosis. The thesis is divided into a theoretical and a practical part. The objective is to bring individual gastroenterological examinations closer using radiological assistance and to describe the role of a radiographer during these performances. The theoretical part mainly describes the anatomy of the digestive tract and its pathology. Further on, the theoretical part contains information on the individual gastroenterological examinations, contrast substances and radiological imaging methods. The practical part has been processed using the data collected from the NIS AKORD hospital system. Based on acquired data, tables and graphics were created, using percentage representation. NIS AKORD data has been accompanied by data that I aquired via a random choice from the Institute of Health Information and Statistics of the Czech Republic database. I have chosen a few figures that are linked to both, the area of radiology and imaging methods as well as gastroenterology. The objective is to describe the process of individual gastroenterology examinations utilizing radiological assistance and to bring the role of the radiographer in the above-mentioned performances to a closer focus.
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Strain Stress Study of Burch-Schneider Split
Řehák, Kamil ; Horyl, Petr (referee) ; Janíček, Přemysl (referee) ; Florian, Zdeněk (advisor)
This thesis deals with problems of the hip endoprosthetics area, namely total endoprosthesis (TEP) with Burch-Schneider (BS) split, in which there are many problems in clinical practice. The hip joint load depends on the patient weight and the performed activity. Sedentary job, little exercise, a lot of stress or poor eating habits and overweight associated with it affect negatively hip joint. Increasing hip joint wear and its pain in movement is necessary in several cases to be solved by a surgical procedure in which TEP is applied. When selecting and subsequently applying individual TEP, it is important to pay attention to creating conditions which will allow good fixation. In case of worse mechanical properties of bone tissue, it is very problematic to ensure stability of the implant. Based on several classifications which assess the degree of hip joint damage, it is possible to select a suitable TEP. The BS split, on which this work is focused, is dominantly used in cases of large defects in the acetabulum area. The use of this cage allows to bridgelarge defects and create a new centre of rotation of the hip. Knowledge of the mechanical properties of hip bone tissue can significantly affect the prediction of BS split damage. For this purpose, it was necessary to perform a biomechanical study, which is focused on the influence of worse mechanical properties of bone tissue on BS split failure. The computational modelling using finite element method implemented in the ANSY S software was used for the solution, which enables to solve the mechanical interaction between bone tissue and TEP with BS split. Due to the absence of bone tissue data before application of TEP with BS split, the variants before application of TEP and after application of resurfacing and standard TEP were solved. All variants were solved with the material properties of bone tissue that were determined based on CT images. In addition, all variants were solved for the case of degraded mechanical properties. Based on the numerical simulations results and the Mechanostat hypothesis, a bone tissue analysis of the hip joint was performed before and after application of TEP and TEP with BS split. The results show the influence of the computational model level, which considers the distribution of bone tissue through the inhomogeneous model of the material. Therefore, the degraded mechanical properties have a major impact on the stability and strain of the BS split, particularly in the cranial part of the acetabulum.
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Degenerative changes in the cervical spine with a focus on the intervertebral disc prolapse and its verification using imaging methods and 3D model
Píglová, Tereza ; Jelen, Karel (advisor) ; Tlapáková, Eva (referee)
Title: Degenerative changes in the cervical spine with a focus on the intervertebral disc prolapse and its verification using imaging methods and 3D model Objectives: The aim of this work is to describe the problems of degenerative changes in the cervical spine with a focus on the intervertebral disc prolapse. The second part deals with the possibility of imaging methods that are able to detect pathological processes. Part of this work is the study of three cases of patients with a diagnosis of disc herniation. In conclusion, there are some possibilities of 3D modeling of the cervical spine. Methods: The theoretical part is based on the available literature. Images from MRI were obtained from medical facilities in Prague, described and assessed by a specialist. After studying the functions suitable graphical programs were created 3D models of the cervical spine. Results: Degenerative changes in the cervical spine naturally come from the aging of the organism, but a number of modifiable factors accelerating the onset. Among such factors include especially hypokinesia and unilateral overloading of cervical spine. Modern imaging techniques can in detail detect these pathological processes, but are limited by the patient's position during the investigation. The resulting series of images are used as...
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