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Abstract(s)
Os eritrócitos saudáveis são células fundamentais do sangue humano, apresentando geralmente a forma de um disco bicôncavo. Devido à sua conformação, estas células possuem capacidades únicas de sofrer deformação celular, o que lhes facilita a passagem por capilares mais pequenos que o seu diâmetro, enquanto transportam o oxigénio e o dióxido de carbono. Cada vez mais, existem estudos que apontam que a deformabilidade dos eritrócitos é afetada por certas condições patológicas, tais como Esferocitose Hereditária, Eliptocitose Hereditária, Ovalócitose Hereditária, Doença Falciforme, entre outras. Estudos indicaram que a deformabilidade dos eritrócitos infetados com P. falciparum é mais reduzida, pois existe um aumento na rigidez dos glóbulos vermelhos. A esferocitose hereditária é caracterizada pela presença de eritrócitos de formato esferócito. Por outro lado, na eliptocitose hereditária os eritrócitos apresentam formato elíptico e, na ovalócitose, os eritrócitos são arredondados ou ovoides. Estas irregularidades na forma dos glóbulos vermelhos, assim como outras características, podem fornecer importantes informações na determinação de um diagnóstico. Esta dissertação tem como objetivo determinar a frequência de vibração livre de modelos tridimensionais de eritrócitos humanos saudáveis e com patologia. Deste modo, é possível compreender como é que estas células reagem quando é induzida uma determinada frequência de vibração, o que pode vir a ser utilizado como forma de diagnóstico. Para isso, recorreu-se à literatura para obter as suas características geométricas e as suas respetivas propriedades mecânicas, tanto para o estado saudável como para a ovalócitose, a patologia considerada para o presente trabalho. As metodologias utilizadas foram o Método dos Elementos Finitos e o Método de Interpolação de Ponto Radial. Assim, no futuro, pretende-se que o trabalho desenvolvido neste projeto ajude no desenvolvimento de novas ferramentas de diagnóstico e de novas alternativas terapêuticas de modo a combater as doenças associadas a este tipo de células.
Healthy erythrocytes are essential cells of human blood, usually presenting a biconcave disk form. Due to their conformation, these cells present unique capabilities to undergo cellular deformation, which makes it easy for them to pass through capillaries smaller than their diameter, while transporting oxygen and carbon dioxide. Increasingly, there are studies pointing out that red cell deformability is affected by certain pathological conditions, such as Hereditary Spherocytosis, Hereditary Elliptocytosis, Hereditary Ovalocytosis, Sickle Cell Disease, and others. Studies have indicated that the deformability of red blood cells infected with P. falciparum is lower, since there is an increase in the stiffness of the red blood cells. Hereditary spherocytosis is characterized by the presence of spherocyte-shaped red blood cells. On the other hand, in hereditary elliptocytosis, the erythrocytes present an elliptical shape, and in ovalocytosis, the erythrocytes are rounded or ovaloid. These irregularities in the shape of red blood cells, as well as other features, can provide important information for diagnosis. This dissertation aims to determine the free vibration frequency, of threedimensional models, of healthy and pathological human erythrocytes. In this way, it is possible to understand how these cells react when a determined vibration frequency is induced, which might be used as a way to diagnose this type of diseases. For this, literature was used to obtain their geometric characteristics and mechanical properties, both in healthy form and for ovalocytosis, the pathology under study in the present work. The methodologies used were the Finite Element Method, and the Radial Point Interpolation Method. Thus, in the future, it is intended that the work developed in this project will help in the development of new diagnostic tools and new therapeutic alternatives, in order to overcome diseases related to this type of cells.
Healthy erythrocytes are essential cells of human blood, usually presenting a biconcave disk form. Due to their conformation, these cells present unique capabilities to undergo cellular deformation, which makes it easy for them to pass through capillaries smaller than their diameter, while transporting oxygen and carbon dioxide. Increasingly, there are studies pointing out that red cell deformability is affected by certain pathological conditions, such as Hereditary Spherocytosis, Hereditary Elliptocytosis, Hereditary Ovalocytosis, Sickle Cell Disease, and others. Studies have indicated that the deformability of red blood cells infected with P. falciparum is lower, since there is an increase in the stiffness of the red blood cells. Hereditary spherocytosis is characterized by the presence of spherocyte-shaped red blood cells. On the other hand, in hereditary elliptocytosis, the erythrocytes present an elliptical shape, and in ovalocytosis, the erythrocytes are rounded or ovaloid. These irregularities in the shape of red blood cells, as well as other features, can provide important information for diagnosis. This dissertation aims to determine the free vibration frequency, of threedimensional models, of healthy and pathological human erythrocytes. In this way, it is possible to understand how these cells react when a determined vibration frequency is induced, which might be used as a way to diagnose this type of diseases. For this, literature was used to obtain their geometric characteristics and mechanical properties, both in healthy form and for ovalocytosis, the pathology under study in the present work. The methodologies used were the Finite Element Method, and the Radial Point Interpolation Method. Thus, in the future, it is intended that the work developed in this project will help in the development of new diagnostic tools and new therapeutic alternatives, in order to overcome diseases related to this type of cells.
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Keywords
Eritrócitos Deformação celular Condições patológicas Métodos numéricos Erythrocytes Cell deformation Pathological conditions Numerical methods