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Vortex pump as a possible heart replacement
Coufalík, Martin ; Klas, Roman (referee) ; Klas, Roman (referee) ; Fialová, Simona (advisor)
The diploma thesis deals with the issue of artificial hearts and ventricular assist devices. The theoretical part describes the heart and its function. Blood is characterized in terms of rheological behavior and the possible criteria for hemolysis are discussed. The following section describes the most commonly used ventricular assist devices, with emphasis on the use of the regenerative pump, including its components. In the practical part, an experimental analysis of two pumps (COV 43 and COV 23) is performed. Furthermore, non-dimensional characteristics of the pumps are constructed using the laws of similarity. In the computational part, the CFD analysis of the regenerative pump is performed by means of stationary and transient calculation. The results are compared with the experimental findings and based on the results, the impeller of regenerative pump was modified.
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Haemolysis and other biochemical evaluations of vacuum-assisted venous drainage in cardiac surgery
Škorpil, Jiří ; Tošovský, Jan (advisor) ; Lonský, Vladimír (referee) ; Semrád, Michal (referee)
Haemolysis and other biochemical evaluations of vacuum-assisted venous drainage in cardiac surgery Aims of the study: Vacuum-assisted venous drainage (VAVD) improves the quality of venous return in procedures using extracorporeal circulation systems (ECC). Nevertheless, there is not an evidence that such high negative pressure applied to ECC in combination with selective bicaval cannulation due to open heart surgery cause a trauma to blood elements and deteriorates organ function. A prospective randomised study was designed to demonstrate that negative pressure of -20 mm Hg to -80 mm Hg does not cause a significant haemolysis and organ deterioration in such procedures. Materials and methods: 85 consecutive patients undergoing combined cardiac surgery procedure with two separate venous cannulas were randomised in three groups A, B and C. VAVD with negative pressure of -20 to -45 mm Hg was applied to 28 patients in group A and negative pressure of -45 mm Hg to -80 mmHg was applied to 28 patients in group B. There was zero negative pressure applied to 29 patients in group C. Six blood samples were taken from each patient and examinated for haemolysis and other indicators of organ deterioration such as hemoblobin, platelet count, free hemoglobin, aptoglobin, lactate-dehydrogenase, aspartate-amino-transferase,...
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A design of the system for continous evaluation of analytical samples quality in a clinical biochemistry laboratory
SVATOŠOVÁ, Kristýna
The aim of my work is to provide information about the process of evaluating analytic quality of samples. This kind of process is recommended in clinic biochemistry laboratory at present. Serum indexes are measured always, in any required sample test whose result can be influenced by sample quality. It is possible to evaluate the degree of haemolysis, icterus and lipemia in patients´ blood samples by the photometric method. The sample haemolysis is mostly caused by bad technic of blood samples taking or their inappropriate transport so that in the end of this process, in regular intervals there is a possibility to find out the level of results changes in connection with concrete laboratory services users. In theoretical part of my work I describe reasons of sample quality decreasing in vivo that´s something people can´t influence because they originate in a patient´s body and in vitro that are caused by wasteful manipulation. In this part there are also principles of the photometrical methods mostly used. The practical part contains the model example that shows how the analyts can be influenced by artificial adding of interfering substances. I could see increasing of some element concentration after making evaluation: Concentration of K increased by 24%, Fe by 10%, bilirubin by 13% and enzymatic activity ALT by 23%, AST by 179%, GMT by 26% and ALP was reduced by 25% in haemolytic serum. In icteric and lipemic serum there isn´t interference on such high level. Icterus causes decreasing of urea by 17%, creatinine by 27%, enzymatic activity ALT by 10% and activity GMT is increased by 11%. Lipemia decreases concentration of creatinine by 8%, enzymatic activity ALT by 6% and bilirubin is higher by 21%. In the end of my work I introduce statistic conclusion laboratory informatics system that gives laboratory management possibility to find out samples of bad quality in connection with concrete applicants and help to make some reparation.
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