Browsing by Author "Craveiro, D. S."
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- An optimization strategy for customized radiotherapy head immobilization masksPublication . Craveiro, D. S.; Loja, M.A.R.; Vieira, Lina Oliveira; Vinyas, M.An effective head immobilization is an important requirement in radiotherapy treatment sessions, although it may also be thought in the future as a precious aid in brain medical imaging. Thus, the present work is focused on the stiffness optimization of a customized head immobilization mask, modeled upon the head reconstruction surface based on computerized tomography images. This paper proposes a strategy supported by a metaheuristic optimization technique and a metamodeling approach for the whole mask, illustrated at its most unfavorable region occurring in the gnathion region.
- Imobilização da região da cabeça por prototipagem rápida para fins de diagnóstico e terapêuticaPublication . Craveiro, D. S.; Loja, M. A.; Vieira, Lina; Sousa, Eva; Costa, Durval C.; Parafita, Rui; Rodrigues, J. A.Objetivo do estudo: Modelar e testar, por procedimentos de prototipagem rápida, máscaras de imobilização da cabeça através da imagem médica. Conclusões: Dispositivos de imobilização construídos por prototipagem rápida têm características favoráveis para aplicação em imobilização em diagnóstico e terapia. Para dispositivos de imobilização da cabeça as diferenças encontradas na análise estática realizada foram mínimas.
- Imobilização da região da cabeça por prototipagem rápida para fins de diagnóstico e terapêuticaPublication . Craveiro, D. S.; Loja, Amélia; Vieira, Lina; Sousa, Eva; C. Costa, Durval; Parafita, Rui; Rodrigues, José AlbertoObjetivo do estudo: Modelar e testar, por procedimentos de prototipagem rápida, máscaras de imobilização da cabeça através da imagem médica. Conclusões: Dispositivos de imobilização construídos por prototipagem rápida têm características favoráveis para aplicação em imobilização em diagnóstico e terapia. Para dispositivos de imobilização da cabeça as diferenças encontradas na análise estática realizada foram mínimas
- Radiotherapy-customized head immobilization masks: from modeling and analysis to 3D printingPublication . Loja, Amélia; Craveiro, D. S.; Vieira, Lina Oliveira; Sousa, Eva; Rodrigues, J. A.; Portal, R. J. F.Immobilization devices may be a valuable aid to ensure the improved effectiveness of radiotherapy treatments where constraining the movements of specific anatomical segments is crucial. This need is also present in other situations, specifically when the superposition of various medical images is required for fine identification and characterization of some pathologies. Because of their structural characteristics, existing head immobilization systems may be claustrophobic and very uncomfortable for patients, during both the modeling and usage stages. Because of this, it is important to minimize all the discomforts related to the mask to alleviate patients’ distress and to simultaneously guarantee and maximize the restraint effectiveness of the mask. In the present work, various head immobilization mask models are proposed based on geometrical information extracted from computerized tomography images and from 3D laser scanning point clouds. These models also consider the corresponding connection to a radiotherapy table, as this connection is easily altered to accommodate various manufacturers’ solutions. A set of materials used in the radiotherapy field is considered to allow the assessment of the stiffness and strength of the masks when submitted to typical loadings.
- Radiotherapy-customized head immobilization masks: from modeling and analysis to 3D printingPublication . Loja, M. A. R.; Craveiro, D. S.; Vieira, Lina; Sousa, Eva; Rodrigues, J. A.; Portal, R. J.Immobilization devices may be a valuable aid to ensure the improved effectiveness of radiotherapy treatments were constraining the movements of specific anatomical segments is crucial. This need is also present in other situations, specifically when the superposition of various medical images is required for fine identification and characterization of some pathologies. Because of their structural characteristics, existing head immobilization systems may be claustrophobic and very uncomfortable for patients, during both the modeling and usage stages. Because of this, it is important to minimize all the discomforts related to the mask to alleviate patients’ distress and to simultaneously guarantee and maximize the restraint effectiveness of the mask. In the present work, various head immobilization mask models are proposed based on geometrical information extracted from computerized tomography images and from 3D laser scanning point clouds. These models also consider the corresponding connection to a radiotherapy table, as this connection is easily altered to accommodate various manufacturers’ solutions. A set of materials used in the radiotherapy field is considered to allow the assessment of the stiffness and strength of the masks when submitted to typical loadings.
- Using 3D anthropometric data for the modelling of customised head immobilisation masksPublication . Loja, MAR; Sousa, Eva; Vieira, Lina Oliveira; Costa, D. M.; Craveiro, D. S.; Parafita, R.; Costa, D. C.Head immobilization thermoplastic masks for radiotherapy purposes involve a distressful modeling procedure for the patient. To assess the possibility of using different acquisition and reconstruction methods to obtain a 3D skin surface model of PIXY-phantom-head and to present a proposal of an alternative head immobilization mask prototype. Phantom head geometry acquisitions using: computed tomography (reconstructed with ImageJ and Osirix); and 3D Laser Scanner (reconstructed with SolidWorks). From these reconstructed surface models, a set of landmarks was measured and subsequently compared with physical measurements obtained with a Rosscraft-Calliper. For statistical evaluation, relative deviations graphics and Friedman-test for non-parametrical paired samples were used, with a significance level of 5%. For a first assessment of the proposed mask performance, a radiotransparent material was considered, the strength and stiffness evaluation is performed using the finite element method. There are small differences between all the acquisitions and reconstructions methods and the physical measurements, statistically significant differences (X2F(6)) = 6.863, p=0.334) were not found. The proposed mask performed well from the strength and stiffness perspectives, leading to the desired immobilization aim. The immobilization mask design proposal may be an effective alternative to the present completely hand-made situation, which presents a high degree of discomfort and stress to the patients.