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An experimental investigation of friction coefficient in hip joint replacements
Tkadlec, Tadeáš ; Urban, Filip (referee) ; Nečas, David (advisor)
This bachelor thesis deals with an experimental analysis of friction coefficient within hip joint replacements. The measurements were realized on Mini Traction Machine device in ball-on-disc configuration. The main goal was to determine the effect of implant material, kinematic conditions and model synovial fluid composition on the development of coefficient of friction as a function of time. For this purpose, three different materials (metal, ceramic, polymer), two mean speeds (5.7 mm/s; 22m/s), three different slide-to-roll ratios (SRR = 0 %, SRR = -150 %; SRR = 150 %) and six various model fluids containing albumin and -globulin in a various ratios and concentrations were employed. The results are evaluated in the form of graphs showing the dependence of friction coefficient on time and are confronted with previously published studies.
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Analysis of THR lubrication with the use of fluorescent microscopy
Tkadlec, Tadeáš ; Daniel, Matej (referee) ; Nečas, David (advisor)
This diploma thesis deals with an experimental analysis of lubrication of total hip joint replacement using fluorescence microscopy, focusing on so-called soft bearing pairs. Experiments were realized using a hip joint simulator, which was modified and refined for fluorescence microscopy. The aim of this diploma thesis was to determine the effect of the individual components of the synovial fluid on the lubrication mechanisms. For this purpose, different model fluids were designed to represent the composition of proteins and other synovial fluid constituents to elucidate the effect of albumin, -globulin and hyaluronic acid on the resulting lubrication performance. The experiments were separate into two categories different in type of load, dynamic (representative walking) and combined (representing standing with short walk). The experimental results were time-dependent fluorescence intensity values, representing dimensionless film thickness parameters. The values were recorded on the graphs and supplemented with fluorescence images taken during the characteristic sections of the measurements. The measured data was subsequently confronted with previously published articles. It was found that the dominant constituent responsible form film thickness is albumin, while -globulin and hyaluronic acid forms thin stable layer enhancing adsorption ability of albumin which contributes to increase of film thickness eventually.
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Analysis of THR lubrication with the use of fluorescent microscopy
Tkadlec, Tadeáš ; Daniel, Matej (referee) ; Nečas, David (advisor)
This diploma thesis deals with an experimental analysis of lubrication of total hip joint replacement using fluorescence microscopy, focusing on so-called soft bearing pairs. Experiments were realized using a hip joint simulator, which was modified and refined for fluorescence microscopy. The aim of this diploma thesis was to determine the effect of the individual components of the synovial fluid on the lubrication mechanisms. For this purpose, different model fluids were designed to represent the composition of proteins and other synovial fluid constituents to elucidate the effect of albumin, -globulin and hyaluronic acid on the resulting lubrication performance. The experiments were separate into two categories different in type of load, dynamic (representative walking) and combined (representing standing with short walk). The experimental results were time-dependent fluorescence intensity values, representing dimensionless film thickness parameters. The values were recorded on the graphs and supplemented with fluorescence images taken during the characteristic sections of the measurements. The measured data was subsequently confronted with previously published articles. It was found that the dominant constituent responsible form film thickness is albumin, while -globulin and hyaluronic acid forms thin stable layer enhancing adsorption ability of albumin which contributes to increase of film thickness eventually.
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An experimental investigation of friction coefficient in hip joint replacements
Tkadlec, Tadeáš ; Urban, Filip (referee) ; Nečas, David (advisor)
This bachelor thesis deals with an experimental analysis of friction coefficient within hip joint replacements. The measurements were realized on Mini Traction Machine device in ball-on-disc configuration. The main goal was to determine the effect of implant material, kinematic conditions and model synovial fluid composition on the development of coefficient of friction as a function of time. For this purpose, three different materials (metal, ceramic, polymer), two mean speeds (5.7 mm/s; 22m/s), three different slide-to-roll ratios (SRR = 0 %, SRR = -150 %; SRR = 150 %) and six various model fluids containing albumin and -globulin in a various ratios and concentrations were employed. The results are evaluated in the form of graphs showing the dependence of friction coefficient on time and are confronted with previously published studies.
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