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Review of methods to determining wear in hip replacements
Zapletal, Jakub ; Vrbka, Martin (referee) ; Ranuša, Matúš (advisor)
This bachelor thesis analysis issues of observation and measurement of wear on hip replacements. First of all there is a description of historical milestones in development of hip prosthesis. Afterwards there is a recherché study of measuring methods and devices, whereas each one of them is reviewed for pros and cons. In the last section these methods are compared and there is an author’s recommendation for the most viable method for observation and measurement of wear on hip prosthesis.
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Design of valve block for hydrostatic recuperative module of vehicle
Ranuša, Matúš ; Robenek, Dětřich (referee) ; Nevrlý, Josef (advisor)
The Master`s Thesis deals with design and construction of a valve block for a hydrostatic recuperative module of a vehicle with a direct application on pneu tyred roller AP 240H produced by the AMMANN company. The thesis aims to analyze recovery functions of the valve block in several operating modes of the roller, followed by a selection of the right hydraulic components from the perspective of predefined parameters and pressure differences. Design specifications are based on measurements and mathematical simulations on the experimental stand. The experimental stand for this application has been developed at 1:4 scale as compared to a real vehicle. The thesis includes also design of the supporting console for the module on the frame of the vehicle. The Master`s Thesis is a part of project EUREKA with cooperation Bosch Rexroth.
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Design of the pneumatic circuits tester
Buš, Martin ; Ranuša, Matúš (referee) ; Kučera, Petr (advisor)
This bachelor thesis deals with the constructional solution of pneumatic circuit tester. In the first part of bachelor thesis there are brief information about Aventics Pneumobil Competition and racing vehicles of BUT team. The distribution of pneumatic cylinders, pneumatic control elements and sensors is outlined. The second part draws out a conceptual solution of load. Based on conceptual solution is developer structural design of pneumatic circuit tester.
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Design of a Rotation Module for a Knee Simulator
Pauliuchenka, Aliaksandr ; Polnický, Vojtěch (referee) ; Ranuša, Matúš (advisor)
The bachelor thesis is focused on the design and construction of a rotational knee joint simulator module. The purpose of the rotational module is to approximate the simulations to the actual movements during the gait cycle. The module will be used for programmed tibial rotation of the spacer. After the boundary conditions were determined conceptual designs of possible solutions were developed and then the selected option was developed. The resulting design allows the implementation of conditions compliant with ISO 14 243-3. The work includes complete drawings and digital data.
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Optimization of hydraulic system for milling machining center
Smíšek, Tomáš ; Ranuša, Matúš (referee) ; Nevrlý, Josef (advisor)
The bachelor thesis is focused on the design of optimized solution of the hydraulic system for milling machining centre. The main points of this work are to assess the current condition, design optimization solutions, construction calculations, final optimized solution and summary of the optimization. The contracting company is HYTEK Ltd. dealing with construction of hydraulic equipments.
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Experimental Assessment of Influence of Polyethylene Liners' Position on Plastic Deformation in the Run-in Phase of Wear
Zeman, Jakub ; Daniel, Matej (referee) ; Ranuša, Matúš (advisor)
The diploma thesis is focused on the run-in phase of total hip replacement. Mutual adjustment of contact surfaces takes place in this phase and polyethylene acetabular cup shows notable creep behaviour. The magnitude of creep deformations is assessed experimentally in relation to acetabular cups orientation in human body after its implantation. The condition of articulating surfaces is also assessed as well as resulting coefficient of friction in run-in phase. Physiological load and kinematics of the artificial joint as well as physiological conditioning is achieved by new module of existing joint simulator, which is created as part of this thesis. Deformations and condition of articulating surfaces are assessed via optical methods and SEM. Findings about the run-in phase are compared with existing FEM analyses to evaluate simplifications used in these analyses. Measurement of creep deformations has also potential to improve the accuracy of acetabular wear diagnosis in clinical practice.
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VOLUMETRIC WEAR ANALYSIS OF HIP JOINT IMPLANTS BY OPTICAL METHODS
Ranuša, Matúš ; Bryant, Dr Michael (referee) ; Dr Prashant K. Sharma (referee) ; Vrbka, Martin (advisor)
Predložená dizertačná práca sa zaoberá analýzou opotrebenia totálnych bedrových endoprotéz za použitia optických metód. V práci bol predstavený nový prístup hodnotenia objemového úbytku materiálu pomocou 3D optického skeneru. Tento nový prístup je časovo efektívny, poskytuje veľké množstvo snímaných bodov na povrchu implantátu. Množstvo bodov umožňuje presnejšiu rekonštrukciu pôvodnej geometrie a prípadné rekonštrukcie nežiaducich poškodení polyetylénovej vložky pri extrakcii. Predstavené metóda bola validovaná za pomoci štandardizovanej gravimetrickej metódy v súlade s ISO 14242. Následne bol optická skenovacia metóda použitá v troch štúdiách zameraných na analýzu opotrebenia, mechanické zmeny artikulujúceho povrchu a mikroštruktúrne zmeny v dôsledku zlyhania implantátu. Analýza 23 extrahovaných polyetylénových vložiek typ Bicon - plus s rozšíreným použitím v Českej republike poukázala na niektoré problémy spojené so zlyhaním implantátu. Adhezívno - abrazívne opotrebenie bolo identifikované v oblasti penetrácie femurálnej hlavice a následné poškodenia ako delaminácia materiálu , plastické deformácie a pitting boli pozorované v okolí tejto oblasti. Analýza materiálových vlastností poukázala na degradáciu mechanických a chemických vlastností, čo bolo prevažne závislé od rozsahu opotrebenia implantátu. U implantátov boli pozorované výrazné plastické deformácie , nárast oxidačného indexu a nižší pomer tvrdosti voči modulu elasticity, v porovnaní s novými vzorkami. Tečenie materiálu a plastické deformácie, ktoré vykazovali všetky extrahované vzorky boli analyzované v závere predloženej dizertačnej práce, na základe testov na nových implantátoch v zábehovom cykle. Cieľom práce je uviesť nový prístup analýzy opotrebenia polyetylénových vložiek za pomoci optických skenovacích metód a preukázať jeho použiteľnosť na analýze súboru extrahovaných implantátov. Výsledky získané pomocou tejto metódy sa ukázali ako vhodné a môžu viesť k lepšiemu pochopeniu procesov opotrebenia a zlyhávania implantátov.
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Design of a Chainsaw Mill
Hynek, Jakub ; Vlašic, František (referee) ; Ranuša, Matúš (advisor)
The bachelor's thesis deals with the construction of a mobile log saw with an adjustable cutting height and attachment to a tree trunk. Part of the work is a search of known solutions for mobile log saws. The next part deals with conceptual designs and the choice of the most suitable solution. Furthermore, individual structural nodes are elaborated for the selected design and the function of individual parts is described. At the end of the work is the evaluation of the proposed structure.
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Influence of surface microstructure on implant lubrication processes in contact
Matovič, Martin ; Odehnal, Lukáš (referee) ; Ranuša, Matúš (advisor)
This bachelor thesis deals with the lubrication of microstructured prostheses of the first metatarsophalangeal joint. The aim of the research is the service life of joint replacements by creating a microstructure on the surface of the material. The work focuses on the influence of microstructures on lubrication processes in contact and coefficient of friction. Fluorescence microscopy in combination with a reciprocating tribometer with the possibility of recording frictional and loaded forces was used to observe the contact area. The number and average particle size of albumin, which plays an important role in contact lubrication, were then examined to record the camera. The testing was performed on two material combinations, namely CoCrMo - Glass B270 (hard pair) and CoCrMo - PMMA (soft pair), which were only four different microstructures. Elsewhere, the influence of microstructures on lubrication processes in contact for hard and soft pairs is indicated, which can be used to design further measurements.
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