Examinando por Materia "Biomedical materials"

Mostrando 1 - 4 de 4
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    Ítem
    Análisis y rediseño del citocepillo
    (Universidad EAFIT, 2010) González Garzón, Luisa Fernanda; Agudelo Gutiérrez, Lina María
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    Ítem
    Computational Study of Cell Mobility and Transport Phenomena Through Textile Vascular Grafts Using a Multi-Scale Approach
    (Universidad EAFIT, 2015) Valencia Cardona, Raúl Adolfo; García Ruíz, Manuel Julio; Bustamante Osorno, John
    Textile vascular grafts are biomedical devices that serve as partial replacement of damaged arterial vessels, prevent aneurysms rupture and restore normal blood flow -- It is believed that the success of a textile vascular graft, in the healing process after implantation, is due to the porous micro-structure of the wall -- Among the key properties that take part in the tissue repair process are the type of fabric and degree of porosity and permeability, defining the ability of a well-controlled environment for the neovascularization, nutrient supply, and cellular transport -- Although the transport of fluids through textiles is of great technical interest in biomedical applications, little is known about predicting the micro-flow pattern and the transport and deposition of individual platelets, related with the graft occlusion -- Often, this information is difficult to obtain experimentally both in vivo and in vitro, representing a great deal of research efforts -- The aim of this work is to investigate how the type of fabric, permeability and porosity affect both the local fluid dynamics at several scales and the fluid-particle interaction among platelets in textile grafts with an anastomosis of end-to-end configuration -- Two types of samples were analyzed: woven and electrospun, this last one has been manufactured -- This study involves both experimental and computational tests -- The experimental tests were performed to characterize the permeability and porosity under static conditions -- The computational tests are based on a multiscale approach where the fluid flow was solved with the Finite Element Method and the discrete particles were solved with the Molecular Dynamic Method -- The fluid-particle interaction was accomplished in one-, two-, and four-ways, where the blood was considered as a suspension of platelets in plasma -- The textile wall was considered as a porous media with two scales of length: straight tubular structure with porous walls for the macro-domain and representative unit cells of fabric for the micro-domain. Additionally, it presents the implementation of a numerical case that includes one of the main applications of textile vascular grafts to repair Abdominal Aortic Aneurysms (AAA) -- The results have shown that the type of fabric in textile vascular grafts and the degree of porosity and permeability affect the local fluid dynamics and the level of penetration of platelet particles through the graft wall at several length scales, thus indicating their importance as design parameters -- It was found that the permeability is strongly depends on the micro-structure of the fabric, changing the local fluid dynamics and the time of residence of platelets inside the wall -- Moreover, the porous walls cause deviations from Poiseuille flow due to leakage flow through the wall from a macroscopic viewpoint -- Lastly, it was possible to observe that the textile wall with different porosities, acting like a barrier between the blood and an aneurysmal zone, affects the flow pattern, the number of platelets adhered to the artificial surface and the time of residence of platelets into the aneurysmal zone -- In conclusion, predicting the flow pattern and the mobility of blood cells through the textile wall before the graft is manufactured, the development of new textile grafts can be improved
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    Ítem
    Injerto óseo a base de espuma de hidroxiapatita
    (Universidad EAFIT, 2007) Mejía Gómez, Diana Carolina; Ossa Orozco, Claudia Patricia
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    Ítem
    Prótesis ocular estética con movimiento: propuesta de diseño de una Superficie de Apoyo Deslizante (SAD)
    (Universidad EAFIT, 2011) Colombo Pulgarín, Juan Camilo; Cortés Ramírez, Jorge Armando; Restrepo Ochoa, Jorge Luis
    Este proyecto se fundamenta en una propuesta de diseño de un dispositivo médico ocular, de carácter no invasivo, que facilita la movilidad de una prótesis ocular estética, alojada en la cavidad anoftálmica de un paciente -- El producto logrado consiste en una interfaz, deslizante por un lado y antideslizante por el otro, la cual se instala por delante de la prótesis, en contacto con la parte interior del párpado, con el fin de minimizar la fricción que existe allí, y que impide la movilidad de la cascarilla, con lo cual el movimiento de la misma no es fiel al del ojo sano del paciente -- La propuesta de diseño desarrollada se compone de cuatro partes: definición del producto, propuesta de diseño de producto, desarrollo del prototipo y evaluación del prototipo -- Como resultado del proyecto se entrega una metodología de diseño aplicada a un dispositivo médico, fundamentada en el QFD para la definición, y dos técnicas de generación de ideas (Brainstorming destructivo-constructivo de trituración y un método de rastreo fundamentado en una analogía), para la propuesta del diseño; además un prototipo es fabricado bajo la técnica de prototipado rápido, y el mismo es evaluado para comprobar su desempeño