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Exploitation of Experiments for Improvement of Level Constitutive Models of Aortic Aneurysm Tissues
Man, Vojtěch ; Horný,, Lukáš (referee) ; Rosenberg, Josef (referee) ; Burša, Jiří (advisor)
This paper deals with the problem of abdominal aortic aneurysms (AAA), taking into account the possibility of using mechanical tests of aortic tissues for improvement of level of their constitutive models. First part of thesis deals with the introduction into the problem, description of the structure of the wall of the healthy aorta, its main components and the degenerative changes which lead to formation of AAA. This is followed by a brief excursion into constitutive modeling, which focuses closely on the description of the models used to describe the mechanical behavior of soft tissues. The theoretical part is then supplemented by a narrower selection of constitutive models used for modeling aortic wall and intraluminal thrombus, together with published results, which are reviewed and discussed at the end of this section. The main part of this thesis is devoted to tests of mechanical properties of arterial tissues. First, the methodology is presented together with the description of the customizations of the laboratory equipments together with the test rig. In addition, attention is focused on the results of mechanical tests of intraluminal thrombus, where the results of both uniaxial tensile tests and equbiaxial testing are presented. Also the influence of distance ILT from the lumen on the mechanical properties of the thrombus is examined. Another area of interest is the investigation of the effect of elastase on the chnage of mechanical properties of pig aorta. In this case, porcine aortas are experimentally tested only by biaxial testing, and the time of elastase action to alter the mechanical properties is analyzed so that the resulting tissue has a similar stress-strain response as aneurysmal tissue. Finally, the results of experimental measurements, limitations and other possible ways of research are summarized.
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Experimental estimation of arterial collagen waviness
Vávra, Jan ; Man, Vojtěch (referee) ; Polzer, Stanislav (advisor)
The bachelor thesis is focused on the experimental estimation of collagen waviness in arterial . The aim of this thesis is to get orientation of fibres from polarized light microscopy. This is possible thanks to phase correlation and image analysis in programe called MATLAB. After that, it is needed to vertify results in program called Hyperfit. Its done by estimating coefficients of constitutive model and comparing them with biaxial tests of porcine aortas.
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Stress-strain analysis of aortic aneurysms
Man, Vojtěch ; Janíček, Přemysl (referee) ; Burša, Jiří (advisor)
This master thesis is focused on stress-strain analysis abdominal aortic aneurysm using ANSYS software. The model of abdominal aortic aneurysm are based on CT scans of five specific patients. The branching arteries are included to the model and one goal of this thesis is decision about their influence of the wall stress. In this thesis was used a hyperelastic materiál model, which is based on mechanical tests done on human arterial samples.
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Stress-strain analysis of the solids with highly curved centerline
Peter, Ondřej ; Man, Vojtěch (referee) ; Novák, Kamil (advisor)
The bachelor thesis deals with stress-strain analysis of the solid with highly curved centerline. The thesis is divided into three main parts: background research, computation modelling and performing of the experiment. All analytical equations and practical examples were summarized in the first part of this thesis. In second part, computation model is solved by using analytical and numerical approach. Next, the analytical and numerical approaches are compared to each other. Third part deals with experiment.
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Stress-strain analysis of the safety frame of the racing car
Kolivošková, Veronika ; Man, Vojtěch (referee) ; Novák, Kamil (advisor)
Topic of this bachelor thesis is the recherché and following deformation-stress analysis of the race car safety cage. This thesis is divided into three parts. The first one is about the introduction of analysis itself and the FIA regulations for homologation static load tests of the race car safety constructions. The second part describes analytical and numerical approach to the deformation-stress solution of a main arch in historical formula 1 car Ferrari 1512. The outputs of these two approaches which were then compared to determine their accuracy and result verification. On this example was executed the contact analysis which was applied in the last part of the thesis. After receiving the results and conclusions from the basic example, the last part deals with the real safety frame model of Subaru Impreza Sti N15. This chapter presents the most important part of the thesis. On the model were executed three static test simulations which have to comply with FIA regulations. The task was solved with FEM modeling.
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Analysis of state-of-art of modelling of atherosclerosis - review and computation
Polišenská, Anna ; Man, Vojtěch (referee) ; Novák, Kamil (advisor)
This Bachelor’s thesis contains a research of state-of-art of computational modelling of atherosclerosis using FEM. At first a medical terminology about atherosclerosis is described. Then the thesis is focused on nonlinear behaviour of the material such as hyperelasticity. It describes chosen constitutive models used for the stress-strain analysis of blood vessels. Within the thesis there is performed an idealized 2D analysis of stress in atherosclerotic common iliac artery. There are drawn and evaluated dependencies of necrotic core and fibrous cap thickness on maximal equivalent stress.
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Experiences of mothers of children with severe intellectual disability
Man, Vojtěch ; Tomášková, Vladimíra (advisor) ; Geissler, Hana (referee)
The bachelor thesis deals with the experience of mothers of children with a severe mental disability. It sums up the issues and impacts the everyday care has on the life of the mothers and their families. It contains a list of social benefits used for funding the child care and a description of social services which help mothers with the care and the integration of the disabled children according to their capabilities. The thesis is based on qualitative research conducted by the author, who interviewed eight mothers of moderately or severely mentally handicapped children to find out their opinions about medical care, behaviour of the family and others, experiences with negotiation with the authorities and the use of social services. The thesis concludes that the important factors for managing the care of disabled children are family cohesion and adequate information from professionals about the existing options. Keywords Children with intellectual disability, motherhood, family, childcare, social benefits, social services.
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Exploitation of Experiments for Improvement of Level Constitutive Models of Aortic Aneurysm Tissues
Man, Vojtěch ; Horný,, Lukáš (referee) ; Rosenberg, Josef (referee) ; Burša, Jiří (advisor)
This paper deals with the problem of abdominal aortic aneurysms (AAA), taking into account the possibility of using mechanical tests of aortic tissues for improvement of level of their constitutive models. First part of thesis deals with the introduction into the problem, description of the structure of the wall of the healthy aorta, its main components and the degenerative changes which lead to formation of AAA. This is followed by a brief excursion into constitutive modeling, which focuses closely on the description of the models used to describe the mechanical behavior of soft tissues. The theoretical part is then supplemented by a narrower selection of constitutive models used for modeling aortic wall and intraluminal thrombus, together with published results, which are reviewed and discussed at the end of this section. The main part of this thesis is devoted to tests of mechanical properties of arterial tissues. First, the methodology is presented together with the description of the customizations of the laboratory equipments together with the test rig. In addition, attention is focused on the results of mechanical tests of intraluminal thrombus, where the results of both uniaxial tensile tests and equbiaxial testing are presented. Also the influence of distance ILT from the lumen on the mechanical properties of the thrombus is examined. Another area of interest is the investigation of the effect of elastase on the chnage of mechanical properties of pig aorta. In this case, porcine aortas are experimentally tested only by biaxial testing, and the time of elastase action to alter the mechanical properties is analyzed so that the resulting tissue has a similar stress-strain response as aneurysmal tissue. Finally, the results of experimental measurements, limitations and other possible ways of research are summarized.
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