This diploma thesis focuses on the monitoring of hemodynamics in intensive care units; the main objective was to create an educational material for newly employed nurses. This educational material should facilitate the adaptation process of nurses at Anaesthesiology-Resuscitation Units (AR) or Intensive Care Units (ICU).The diploma thesis is divided in two parts: theoretical and empirical. The topics covered by the theoretical part include the concept of intensive care, the technical equipment, the scope of work of intensive care nurses, anatomy and physiology of the cardiovascular system, cardiovascular system monitoring, hemodynamic monitoring, adaptation of new nurses at the workplace, and the possibilities of educational methods aimed at newly employed nurses. The empirical part was conducted as qualitative inquiry in the form of interview. The interviews were semi-standardised and they were held at the AR unit in the České Budějovice Hospital. The subjects were the nurses from the RES 1 and RES 2 stations. The first part of the research inquiry consisted in interviews with the nurses at the Anaesthesiology-Resuscitation unit. The interviews were not taped, due to the respondents' request. All the answers were carefully recorded and immediately transcribed and processed to prevent any inaccuracy of information. The results were organised in charts according to the categorisations, in a well-arranged manner. The second phase consisted in creating the educational material for the newly employed nurses and the third phase concluded the project by distributing the educational materials at the hospital unit where the interviews were conducted. The nurses could therefore assess whether the educational material meets their requirements and will be useful in practice. The respondents were interviewed again and the results were subsequently also organised in charts.The results of the research inquiry show that the nurses at the Anaesthesiology-Resuscitation Unit in the České Budějovice Hospital perceive the correct hemodynamic monitoring as important, that they know what hemodynamic monitoring is and are aware of the monitoring possibilities. The nurses of this unit perform both invasive and non-invasive monitoring of hemodynamic parameters. The basic task is measuring the central venous pressure and arterial pressure. Other parameters are monitored by the doctors with the application of the Swan-Ganz catheter. The most frequently used monitors are PICCO, Lidco, Vigileo and Vigilance. All interviewed respondents agreed that their only help during the adaptation process was the manufacturers' materials and the advice from the nurse-trainers. A small part of the respondents was trained directly by the company distributing the monitors. The final phase of the research inquiry revealed that the nurses like the new educational material but they are afraid that it will end up collecting dust as the other materials supplied by students. The interviews established that it is easier to directly communicate the necessary information to the new nurses along with practical demonstration than to recommend an educational material for studying of at least the theoretical part.

The diploma thesis deals with non-invasive and invasive monitoring of the cardiovascular system, focusing on non-medical health workers. The aim of the work was to analyze the knowledge of non-medical health workers in selected areas of cardiovascular monitoring. The data was obtained in the form of a non- standardized questionnaire created by myself. For the research were selected non-medical health workers working in Prague hospitals in coronary units and postoperative cardiac surgery units. The total number of respondents who participated in the research was 108. The results of the survey revealed that non-medical staff are relatively well versed in the issue of cardiovascular monitoring. A rather surprising finding was that most respondents did not use foreign literature to study cardiovascular monitoring. As part of the comparison of the respondents, the better knowledge of cardiovascular monitoring was presented in non-medical staff of the Department of Postoperative Cardiac Surgery. Compared in relation to the highest educational attainment, university graduates have demonstrated a higher level of knowledge than others. Based on achieved data, it was created a study text for newcomers, which contains basic information for better orientation in the given issue. keywords: cardiovascular...

This thesis is motivated by a problem of cerebral aneurysms, which are abnormal bulges on the arteries which supply blood for our brain. These aneurysms can rupture and cause death or permanent neurological deficits. To study the evolution of aneurysms and assess the risk of rupture, mathematical modelling might be used to compute otherwise unobtainable information about blood flow inside the aneurysm. For this reason it is essential to be able to model blood flow in sufficiently high resolution. A goal of this thesis was to implement standard projection method for the solution of unsteady incompressible Navier-Stokes equations using the free finite element software FEniCS to create a working code adjusted to the need of this particular application. The incremental pressure correction scheme was chosen. Various shortcomings of this method are described and a proper choice of boundary conditions and other implementation issues are discussed. A comparison of computed important hemodynamic indicator wall shear stress using new and previously used solution approach are compared. A test of the new code for parallel efficiency and performance on finer meshes for a real medical case was conducted. Powered by TCPDF (www.tcpdf.org)

The thesis includes a general introduction to monitoring and measurement of blood pressure of horses, the design of algorithms for pressure curve detection and the calculation of respiratory variabilities in mechanical ventilation under anaesthesia. The first two chapters focus on anatomy, on characteristics of blood flow and on vascular system. Then it deals with the measurement of blood pressure, monitoring of a horse under anaesthesia and it describes particular thermodynamic parameters. In the following part of the thesis, the methods of pressure curve detection are described. The last part contains the description of an algorithm designed for detection of pressure curve of horses in the environment of the program LabVIEW. The program calculates, displays and saves variabilities of systolic pressure, pulse volume, pressure amplitude, pulse frequency, peripheral resistance and vascular expansion from the detected values.

The incompressible fluid flow around the geometries of cerebral artery aneurysms is studied in this thesis. The aneurysm is a local extension of a vessel. This disease is dangerous only in the case of rupture. Then the blood is released into the brain. The need of accurate computation of the velocity and pressure fields in this geometries is motivated exactly by the question which aneurysm has tendency to rupture. The finite element method (FEM) is used for the computation of the flow. A good domain discretization is one of the main step in FEM. Modern computed tomography is able to produce series of the two- dimensional images and it is necessary to create an appropriate three-dimensional model of the tissue. This thesis includes the description of the mesh generation and the ways to smooth and improve the meshes. In the theoretical part the equations of fluid flow are formulated. A suitability of a choice of boundary conditions is discussed. Weak formulation for the equations and its discretization are presented. In the practical part velocity and pressure fields are computed by the various finite elements. Wall shear stress which plays an important role in the evolution of an aneurysm is also computed on the introduced meshes. Comparison of mesh smoothing filters, used finite elements and used...

Arterial stenosis is a disease characterized by the buildup of a waxy substance inside the artery, which is associated with certain risks. It is difficult to eval- uate the severity of the stenosis, yet the diagnosis can become more accurate using computational fluid dynamics simulations. The present thesis introduces and applies the model of hemodynamics based on the Navier-Stokes equations, implemented in the FEniCS software employing the finite element method. The main focus lies on the prescription of the boundary condition at the outlet of the computational domain. The impact of the outlet boundary condition on medically significant quantities such as the wall shear stress is analyzed in a two- dimensional benchmark case. It appears that the right choice of the boundary condition is fundamental, in particular when vortices occur and propagate across the outlet boundary. The next part of the work is dedicated to the prescrip- tion of the outflow rate in the case of more than one outlet, corresponding to an artery branching inside the computational domain. The physically meaningful flux distribution is derived introducing Murray's law and its extension. Finally, the blood flow is simulated in a three-dimensional geometry of a patient-specific carotid artery. 1

This thesis is focused on study of blood flow through the descending aorta using mag- netic resonance imaging and computational hemodynamics. This combination enables simulations of blood flow in patient specific geometries and under various circumstances such as higher heart rate, velocity or blood pressure. The theoretical part describes the governing equations of the blood flow and possible choices of boundary conditions. The weak formulation and discretization in space and time, which leads to the finite element approximation, is presented. The magnetic resonance data is presented in the second part. The process of segmenta- tion is described together with the preparation of the velocity data for comparison with simulation results. Limitations of magnetic resonance imaging are also presented. The developed methodology is one of the contributions of this thesis. The qualitative and quantitative comparison of simulation results and the magnetic res- onance velocity data is presented in the third part. The main result of the thesis is in the comparison of the flow under different wall boundary conditions. The most important finding is that the best fit for the data is the free-slip wall boundary condition, which is the opposite of commonly used no-slip wall boundary condition. 1

In this thesis we introduce a new fluid-structure interaction model in the Eulerian description. This model is developed for blood flow in viscoelastic artery. For the fluid part a non-Newtonian model Oldroyd-B is used and for the structure part Kelvin-Voigt model is employed. Kelvin-Voigt model will be reached by a limiting process of the Oldroyd-B model. Interface between these two materials is guaranteed by conservative level-set method. Numerical tests of this model is performed by finite element method. This model is used for a simulation of two problems: a two dimensional channel with viscoelastic walls and pulsating inflow and Turek-Hron FSI benchmark. 1

Recent years have seen a rising interest in the use of computational fluid dynamics for investigating the hemodynamics in brain aneurysms. Hemodynamic parameters, such as wall shear stress or oscillatory shear index, are among the indicators used to detect higher risk of aneurysm rupture. This thesis describes the blood flow by generalized Navier-Stokes equations with the Navier slip boundary condition imposed on the impermeable rigid vessel wall, which is implemented by way of Nitsche's method. The influence of constitutive models and the Navier slip wall boundary conditions on the resulting blood flow and hemodynamic parameters is investigated. Five different non-Newtonian constitutive models are first compared on a 2D rectangular domain. The Carreau-Yasuda, modified Casson, and Quemada models are then employed to investigate the differences in one patient-specific aneurysm geometry obtained by CT scan. All non-Newtonian models are compared with the Newtonian model. Both steady and pulsatile simulations are performed to obtain the velocity field and hemodynamic quantities, such as wall shear stress, time-averaged wall shear stress, oscillatory shear index, and oscillatory velocity index. The results for this particular case showed that non-Newtonian models do not have a significant impact on the computed...

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