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Design of parts of tribometer with reciprocating motion
Dražka, Ondřej ; Vrbka, Martin (referee) ; Čípek, Pavel (advisor)
The bachelor thesis deals with design of parts of tribometer with reciprocating motion. Several conceptual solutions are made on base of existing studies from which the best solution for given application is selected. The tribometer will be used for experimental measuring on real cartilage which should lead to better understanding of friction and lubrication processes in synovial joint. The outcome of this thesis are component parts along with the manufacturing drawings.
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Biomechanical Study of Hand
Krpalek, David ; Janíček, Přemysl (referee) ; Horyl, Petr (referee) ; Florian, Zdeněk (advisor)
This work deals with issue of human wrist and appropriate total wrist implant allowing a restoration of hand mobility approaching physiological condition after traumatic and degenerative diseases. Treating these diseases are very complex. These issues including a biological and medical issues. To determine the appropriate treatment method and select right total wrist implant is important to know the behavior the human wrist at all stages in terms of medical and biomechanical. For this reason, it was developed a biomechanical study including computation model of human wrist allowing solution of strain and stress of hand in physiological and pathological conditions and condition after total wrist implant. The frost remodeling of bone tissue was used for analysis of human wrist bone tissues and bone tissues after application of total wrist implant RE-MOTION™ Total Wrist.
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The Effect of Synovial Fluid Constituents on Friction and Lubrication of Articular Cartilage
Čípek, Pavel ; Dr. Prashant K. Sharma (referee) ; Muňoz, Anna Neus Igual (referee) ; Vrbka, Martin (advisor)
Práce se zabývá problematikou biotribologie modelu synoviálního kloubu. Cílem práce je popsat vliv složek synoviální kapaliny na formování mazacího filmu v modelu synoviálního kloubu. Práce je zaměřena na experimentální analýzu součinitele smykového tření a jeho propojení s pozorováním adsorbovaného mazacího filmu v kontaktu pomocí fluorescenční mikroskopie. Součástí práce je návrh tribometru, který umožňuje vizualizaci v průběhu experimentů. Tribometr je vyroben, kalibrován a verifikován pomocí komerčního tribometru. Dále je součástí práce návrh metodiky experimentů včetně návrhu postupu pro zpracování a hodnocení výsledků. Pro zpracování záznamu z vizualizace kontaktu byl navržen speciální software, který pracuje na principu segmentace obrazu. Poslední část práce je zaměřena na aplikaci vyvinuté metodologie spolu s nově navrženým tribometrem, což umožňuje posoudit roli složek modelové kapaliny u formování mazacího filmu v modelu synoviálního kloubu. Experimentální část je založena na měření tření za současné vizualizace kontaktu. Tato práce prezentuje originální výsledky rozšiřující oblast biotribologie synoviálního kloubu, které mohou pomoci dalšímu rozvoji účinné léčby pacientů s nemocnými klouby.
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Design of Simulator for Friction Analysis in a Knee Joint
Dobrovolná, Lucie ; Studený, Zbyněk (referee) ; Sedlák, Josef (advisor)
This bachelor thesis deals with the construction of a device simulating the kinematics of the knee joint. Boundary conditions are inspired by the ISO 14243-3 standard and are based on the selection of suitable components. The simulator will be able to record the course of the coefficient of friction between the cartilage forming the translational motion, the CoCr head forming the rotational motion and the pressing force, thus helping to better understand the biotribological processes between the selected surfaces. The design must be developed with respect to the relative movement of components, sample material and lubrication. The introductory part of the text deals with an overview of current knowledge, which serves as the main input to the creation of the structure. Based on the research part, several conceptual solutions are created in the field of construction and method of friction measurement. The resulting solution is selected from the proposed concepts, which meets predetermined conditions and contains specific drives and sensors.
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Image processing of MRI
Němcová, Simona ; Jiřík, Radovan (referee) ; Krátká, Lucie (advisor)
This thesis deals with the cartilage imaging using magnetic resonance. At first, there is mentioned physical principle of the magnetic resonance phenomenon and the most commonly used excitation sequences, followed by the description of the 9.4 T MR imaging system Bruker BioSpec 94/30 USR, which was used for measurement in the practical part. The next part is dedicated to the composition of cartilages and describes the temporomandibular joint, due to its suitability as an object for cartilage imaging. The series of MR scans of temporomandibular joint were taken with different acquisition parameters and evaluated by program designed through the MATLAB software. The program can be used for viewing scanned images, evaluating their contrast and determining the T1 relaxation time of the tissues by creating T1 maps.
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Automatic smoothing 3D models of cranial embryonic mouse cartilage
Kočendová, Kateřina ; Harabiš, Vratislav (referee) ; Jakubíček, Roman (advisor)
The focus of this thesis is the smoothing of manually segmented 3D models of mouse embryo craniofacial cartilege. During the process of manual segmentation, artefacts and other imperfections appear in the final models and need to be repaired. Firstly, manual segmentation is corrected using gradients and thresholding. Subsequent smoothing methods are constructed based on theoretical research. Algorithmizing is executed in the MATLAB environment. All the designed algorithms are then tested on selected models. Statistical evaluation is determined using the Srensen–Dice coefficient, where manually smoothened models cleared of all artefacts are used as the gold standard.
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Friction measuring of human joints
Šnejdar, Radim ; Ranuša, Matúš (referee) ; Čípek, Pavel (advisor)
This bachelor thesis concerns about the tribology of real joints. The aim of this work is an elucidation of the influence of chosen operating conditions on shear force coefficient. It deals especially about speed, strain and rehydration. The experimental tasks will be realized on tribometer, which is available in laboratories of ÚK. In this work, current state of knowledge in the area of discussed issues are described. Also the device and measured methods which help to measure and evaluate data files. In the last section of this work, the results are evaluated and the following conclusions are established.
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Elaboration and introduction of the method for determination of some proteins
Hruzík, Ondřej ; Buňka, František (referee) ; RNDr.Karel Gebauer (advisor)
Core protein of aggrecan has a significant share on the correct function of articular cartilage. Its lack or structural failure could be the reason for the disfunction of the cartilage. The culture of chondrocytes taken from a pork articular cartilage was used for the study of aggrecan production. The monolayer culture method offers the model system which has enabled us to watch the aggrecan production into growth medium. The aggrecan synthesis was stimulated in the media with addition of L-methionin, L-serin and sodium selenite pentahydrate. Methionin and serin are antecedents of sulphur amino acid of cysteine, whose role is incredibly important for the correct function of core protein. Growth media and chondrocytes were analysed with the help of the automatic amino acids analyzer unit after acid or oxidative hydrolysis. The analyse established the amino acid representation. The main attention was paid to cysteine. The changing concentrations of this amino acid were showing if the antecedents in the addition are used for its production and, therefore, if it is possible to stimulate the production of core protein with these antecedents. The results are discussed in the conclusion of this thesis. The next step should be the detection of the concentration of synthesized aggrecan by the immunological method. Presently this method is very expensive. Therefore, the method of setting the core protein of aggrecan with the help of suitable amino acid was used for the first tests.
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Comparative analyses of cranial skeletogenesis and odontogenesis in basal Ray-finned fishes
Pospíšilová, Anna ; Černý, Robert (advisor) ; Přikryl, Tomáš (referee) ; Buchtová, Marcela (referee)
Skeletal (cartilaginous, bony, and dental) tissues undoubtedly exemplify the key innovation of vertebrates. Among all recent vertebrates, the most numerous and successful lineage is represented by the Ray-finned fishes that, accordingly, exhibit amazing variety of skeletal architectures and phenotypic adaptations. In order to depict fundamental principles of fish cranial skeletogenesis the developmental formation of skeletal architectures was described, compared and analyzed using members of early branching fish lineages, that exemplify very different strategies of skeletogenesis. While the Senegal bichirs and the Tropical gars are heavily armored forms with massive exoskeleton and hyperossified dental structures covering the whole oropharyngeal region, the European sterlets, on the contrary, possess mostly cartilaginous skeleton and reduce their dental structures during early development. Whole analysis is underpinned by the Northen pike, teleostean species with lightened skeletal architecture with comparable number of cranial elements. The present study represents the first complex comparative analysis of their skeletogenesis and odontogenesis. This allowed to define developmental strategies founding different lineage-specific skeletal architecture of vertebrates. Comparative description of...
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Tribology of hydrogels for articular cartilage replacement
Křížová, Michaela ; Ranuša, Matúš (referee) ; Vrbka, Martin (advisor)
The bachelor's thesis deals with the description of the tribological properties of focal joint implants in the place of a cartilage defect. The application of focal implants is aimed at a group of younger patients who have to undergo surgery to repair damaged cartilage, but a total replacement is not suitable for them due to its lifetime. The contact of the focal implant and the opposite cartilage was simulated using metal samples and hydrogel, which has very similar properties to natural cartilage. For a possible comparison of values, a tribological measurement of the cartilage samples against the hydrogel was carried out. This pair serves as a model for defining friction in a healthy joint. The main task of this thesis was to determine the coefficient of friction of Ti6Al4V, Ti6Al4V+DLC, CoCrMo and cartilage against the hydrogel. The experiments were carried out using a tribometer in a pin-on-plate configuration. The Ti6Al4V alloy without coating and with DLC coating came out with the lowest coefficient of friction for both variants, almost identically 0.0526. Higher friction was measured for CoCrMo, but it differed from the titanium alloy to one-hundredth. On the contrary, the highest coefficient of friction was unexpectedly manifested in the cartilage samples, where the lowest friction was assumed. The error was due to poor selection of cartilage samples. The thesis simply describes the tribological behaviour of focal implants and the result is a material with the lowest coefficient of friction. The measurements performed could help further research into the issue of focal implants.
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