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Videonistagmoscopia digital com lente de contato para identifica??o de movimentos oculares e apoio ao topodiagn?stico da vertigem posicional parox?stica benignaGrossi, Rafaeli Sagrilo 29 April 2016 (has links)
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Previous issue date: 2016-04-29 / Benign paroxysmal positional vertigo (BPPV) is characterized by vertigo crisis, triggered by sudden head position changes, associated with the appearance of paroxysmal positional nystagmus. The characterization of torsional nystagmus has fundamental importance while conducting a patient with BPPV, because it turns possible to identify the affected semicircular channel, as well as the physiopathological mechanism involved. However, the majority of existing videonystagmography devices are not capable of identifying these torsional movements with the required precision. This work aims to develop and test a method to model and identify torsional eye movements, when present. This new model uses a videonystagmograph prototype, comercial ophthalmic contact lens with geometric figures and a computer program, which was specially designed with this objective. Complementarily, a webapp program has also been created to support the topodiagnosis of the BPPV. Subjects with BPPV and without BPPV have been evaluated. The subjects have undergone the Dix-Hallpike maneuver, using the contact lens with geometrical figures on the left eye and the capture device. Among these evaluations, forty videos have been recorded (23 with counter-clockwise rotating movement phenomena, 10 clockwise and 7 videos with eye at rest). The extracted videos were analyzed with the developed software. The success rate in classifying the direction of the rotating movement (counter-clockwise or clockwise) and the resting position was evaluated. The accuracy of the software in correctly finding the geometric lines of the ophthalmic lens was also evaluated. Among the forty analyzed videos, the software had a success rate of 85% (70-94%) in identifying direction of movement or at rest; considering only the success rate in direction of movement, the total was 81% (64-93%). The accuracy in the measuring of the interest zone of the frames was 82,2% (81,5-82,8%) with p<0,05 significance level. Therefore, the new developed model should be able to have an important part on the topodiagnosis of the BPPV in the future, providing a more precise and effective therapeutic management to the patients with this disease. / A vertigem posicional parox?stica benigna (VPPB) ? caracterizada por crises de vertigem, desencadeadas por mudan?as bruscas de posi??o da cabe?a, associada a um nistagmo posicional parox?stico. A caracteriza??o do nistagmo rotacional ? de fundamental import?ncia na condu??o do paciente com VPPB, pois ? atrav?s das caracter?sticas do nistagmo que ? poss?vel identificar o canal semicircular acometido, bem como o mecanismo fisiopatol?gico envolvido. Por?m, a maioria dos dispositivos de videonistagmoscopia existentes n?o s?o capazes de identificar com precis?o esses movimentos rotat?rios. A proposta deste trabalho foi desenvolver e testar um novo modelo de quantifica??o de movimentos oculares rotat?rios quando presentes. Este novo modelo utiliza prot?tipo de videonistagmosc?pio, lente de contato oft?lmica comercial com figuras geom?tricas e o desenvolvimento de um software especificamente para esta finalidade. De forma complementar, uma WebApp tamb?m foi criada para auxiliar no topodiagn?stico da VPPB. Participaram do estudo 4 indiv?duos com VPPB e 4 sem VPPB. Os sujeitos foram submetidos ? manobra de Dix-Hallpike, utilizando a lente de contato com formas geom?tricas no olho esquerdo e o dispositivo de captura. Dessas manobras, foram gravados 40 v?deos (23 com fen?menos de movimento rotat?rio anti-hor?rio, 10 no sentido hor?rio e 7 v?deos com olho em repouso). Os v?deos extra?dos foram analisados com o software criado. Foi analisada a taxa de acertos na classifica??o da dire??o do fen?meno de movimento rotat?rio (anti-hor?rio ou hor?rio) quando presente ou v?deo repouso. Tamb?m foi avaliada acur?cia do software em encontrar corretamente as marcas geom?tricas da lente oft?lmica. Dos 40 v?deos analisados, o software obteve como taxa de acerto da dire??o ou repouso valor de 85% (70-94%); considerando-se apenas a taxa de acerto da dire??o, o valor foi de 81% (64-93%). A acur?cia na medida da zona de interesse dos frames foi de 82,2% (81,5-82,8%) com n?vel de signific?ncia de p<0,05. Assim, o novo modelo desenvolvido poder? no futuro ter um papel importante no aux?lio do topodiagn?stico da VPPB, proporcionando aos doentes com esta enfermidade um manejo terap?utico mais preciso e eficaz.
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