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Comparative analysis of physiological, degenerative and postoperative lumbar spine using computational modeling
Krejbychová, Adéla ; Návrat, Tomáš (referee) ; Vosynek, Petr (advisor)
This diploma thesis deals with the comparative analysis of the physiological, degenerative and postoperative state of the lumbar spine. The problem was solved by computational modeling using the finite element method. For this solution, it was necessary to create appropriate computational models. The spine physiological state was compared with cases of the lumbar spine with different levels of spondylolisthesis, cases of the lumbar spine with different sacral angles, and cases of lumbar spine with applied fixators. Based on the performed analyses, it was found that spine degenerative state has a great influence on the distribution of stress in the vertebral discs and the vertebra itself. Compared to the physiological state, with increasing level of the spondylolisthesis the stress in the vertebral discs increases, while the stress in the vertebral section decreases. Furthermore, the spondylolisthesis affects the force flow. The higher the level of the spondylolisthesis, the more the force flow is shifted onto the posterior articular ligaments. The best results in terms of the spine physiological state were achieved with the applied fixator model.
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Analysis of manufacturing technology humeral nail
Duda, Jan ; Slaný, Martin (referee) ; Kalivoda, Milan (advisor)
This bachelor thesis is focused on technological manufacturing proces of humeral nail system in the company Medin a.s. The thesis contains descriptions of technological manufacturing processes including used machines. There is also mentioned infomation about materials which are used for the manufactory and an operating procedure for nail insertion into a human body.
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Stress-strain analysis of spinal segment with fixator
Mach, Ondřej ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This Master’s thesis deals with strain-stress analysis of a spine segment with an introduced fixator and a spine in natural physiological state. The work starts with a research study of literature sources that focus on similar issues. Furthermore, basic anatomy terminology and basic procedures for human spine stabilization were described. The formulated issue was resolved by computational modelling with the use of the finite element method. This solution requires a suitable computational model to be produced. This model consists of partial geometry, material, bond, and loading models. The geometric model was produced on the basis of CT scan images of a 60-year-old man which were used for producing five spine vertebrae T11–L3. Moreover, the geometric model consists of four intervertebral discs and eight articular cartilages. The material model includes homogeneous, heterogeneous and degraded properties of bone tissue. The strain-stress analysis was performed for seven loading states, which concern basic movements of human spine – standing, bending forward, bending backwards, bending left, bending right, left rotation and right rotation, with the use of ANSYS software. The assessed and analysed quantities include spine segment displacement, contact pressure of articular cartilages and stress on the fixator.
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Biocompatible titanium alloys and theirs application
Hofírek, Michal ; Kohout, Jan (referee) ; Věchet, Stanislav (advisor)
This thesis presents use of titanium alloys in medical applications in form of literature research. In first part the basic properties of titanium as element are discussed as well as its behavior in alloys. Next part focuses on proper explanation of term biocompatibility and sums up specific requirements for alloys used in orthopaedic applications. These properties are shown on alloy Ti-6Al-4V ELI and other selected titanium based alloys which are currently being developed.
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On the advanced production technology of UHMWPE joint implant part
Urbancová, Kateřina ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor’s thesis is dealing with the problematics of individual joint replacements. The thesis summarizes the modern materials used for making artificial joint replacements, but it concentrates mainly on the plastic femoro-tibial part of the implant, usually manufactured from ultra-high molecular weight polyethylene. This material is the best choice when manufacturing the articulating surface of the joint replacement at the moment. The thesis pays attention to the polyethylene surface treatment, as the quality of the surface affects the wear of the plastic, which is critical for the implant lifespan. The thesis also focuses on analysis of the coefficient of friction of UHMWPE in contact with the titanium femoral component. Another part of this thesis is also a wear analysis of used tibial inserts made of UHMWPE and the mechanisms of wear.
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Middle ear implants in clinical practice
Ondrášková, Lucie ; Janoušek, Oto (referee) ; Provazník, Ivo (advisor)
The paper is a brief overview of anatomy of the ear, hearing screening, diseases and disorders affecting the organ of hearing. Next, there are listed the first ideas implants and their materials and there are described middle ear implants used nowadays and the latest surgical procedures, relevant legislation and the reaction of the body on the implant. The practical part will consist of collecting clinical data comprise the number and types of operations, air and speech audiometry and subsequent statistical evaluation. At the conclusion will be discussed and reviewed the statistics.
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A study on sintering technologies of Ti-6Al-4V alloy for implants
Bučková, Katrin ; Ohnišťová, Petra (referee) ; Píška, Miroslav (advisor)
This work contributes to the problem of individual replacements of worn human joints by applying new types of implants and materials, made using modern additive technologies (melting of metal powders by laser and electron beam). The main attention is paid to the method called Electron Beam Melting used in the ARCAM Q10plus. Analysis of samples of the sintered Ti6Al4V - ELI alloy is made from the point of view of production precision and quality after sintering in different technological modes and the surface quality reached after turning and tumbling, including measurement of other physical quantities.
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