Thoracic wall reconstruction using ultrasound images to model/bend the thoracic prosthesis for correction of pectus excavatum

Pectus excavatum is the most common congenital deformity of the anterior thoracic wall. The surgical correction of such deformity, using Nuss procedure, consists in the placement of a personalized convex prosthesis into sub-sternal position to correct the deformity. The aim of this work is the CT-scan substitution by ultrasound imaging for the pre-operative diagnosis and pre-modeling of the prosthesis, in order to avoid patient radiation exposure. To accomplish this, ultrasound images are acquired along an axial plane, followed by a rigid registration method to obtain the spatial transformation between subsequent images. These images are overlapped to reconstruct an axial plane equivalent to a CT-slice. A phantom was used to conduct preliminary experiments and the achieved results were compared with the corresponding CT-data, showing that the proposed methodology can be capable to create a valid approximation of the anterior thoracic wall, which can be used to model/bend the prosthesis

PHB-PEO electrospun fiber membranes containing chlorhexidine for drug delivery applications

Fiber meshes of poly(hydroxybutyrate) (PHB) and poly(hydroxybutyrate)/ poly(ethylene oxide) (PHB/PEO) with different concentrations of chlorhexidine (CHX) were prepared by electrospinning, for assessment as a polymer based drug delivery system. The electrospun fibers were characterized at morphological, molecular and mechanical levels. The bactericidal potential of PHB and PHB/PEO electrospun fibers with and without CHX was investigated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by disk diffusion susceptibility tests. Electrospun fibers containing CHX exhibited bactericidal activity. PHB/PEO-1%CHX displayed higher CHX release levels and equivalent antibacterial activity when compared to PHB/PEO with 5 and 10 wt% CHX. Bactericidal performance of samples with 1 wt% CHX was assessed by Colony Forming Units (CFU), where a reduction of 100 % and 99.69 % against E. coli and S. aureus were achieved, respectively.

Produto Aquaoli: projeto de design industrial em aquariofilia

Esta dissertação de mestrado, apresenta a elaboração de um projeto de design industrial em aquariofilia - Aquaoli. Pretende-se criar uma nova tipologia de aquários inovadora e distinta, projetando o produto com o intuito deste cumprir com todos os parâmetros exigidos pelo mercado e produção do mesmo. Definiu-se a criança entre os 7 e os 11 anos como público-alvo deste projeto. Assim, pretende-se um resultando promissor para a empresa AQUATLANTIS apostar e lucrar com o seu desenvolvimento. Para que este projeto obtivesse bons resultados, foi realizada uma pesquisa aprofundada, desde a aquariofilia (a sua história, biologia e mercado), do aquariófilo atual (psicologia do consumidor e as suas responsabilidades), até ao estado da arte (da AQUATLANTIS e dos produtos existentes no mercado). Este projeto foi desenvolvido em várias vertentes de design, procurando ser o mais completo possível. Isso foi viável com o desenvolvimento do produto e de todos os seus componentes em três dimensões, o desenvolvimento de maquetes e de protótipos do produto, o desenvolvimento do packaging e campanha promocional, a definição de preço custo e métodos de produção dos objetos, entre outros parâmetros. Obteve-se um projeto de design industrial bastante completo e com potencial para ser implementado no mercado, cativando a atenção do público-alvo e obtendo vendas elevadas. O aquário apresenta-se distinto dos existentes, principalmente no facto de ser modular, muito interativo, pedagógico e incorporar uma estrutura invulgar e particularmente cativante para as crianças. Este produto subdivide-se em dois conjuntos vendidos separadamente (Aquarium Pack e Kit-1 Pack), apresentando assim uma estratégia de marketing que pretende que a criança que o adquira pela primeira vez, venha a desejar adquirir mais produtos desta gama, procurando aumentar a sua estante e/ou o número de aquários e animais que incorpora na mesma.

Validation of percutaneous puncture trajectory during renal access using 4D ultrasound reconstruction

Background: An accurate percutaneous puncture is essential for disintegration and removal of renal stones. Although this procedure has proven to be safe, some organs surrounding the renal target might be accidentally perforated. This work describes a new intraoperative framework where tracked surgical tools are superimposed within 4D ultrasound imaging for security assessment of the percutaneous puncture trajectory (PPT). Methods: A PPT is first generated from the skin puncture site towards an anatomical target, using the information retrieved by electromagnetic motion tracking sensors coupled to surgical tools. Then, 2D ultrasound images acquired with a tracked probe are used to reconstruct a 4D ultrasound around the PPT under GPU processing. Volume hole-filling was performed in different processing time intervals by a tri-linear interpolation method. At spaced time intervals, the volume of the anatomical structures was segmented to ascertain if any vital structure is in between PPT and might compromise the surgical success. To enhance the volume visualization of the reconstructed structures, different render transfer functions were used. Results: Real-time US volume reconstruction and rendering with more than 25 frames/s was only possible when rendering only three orthogonal slice views. When using the whole reconstructed volume one achieved 8-15 frames/s. 3 frames/s were reached when one introduce the segmentation and detection if some structure intersected the PPT. Conclusions: The proposed framework creates a virtual and intuitive platform that can be used to identify and validate a PPT to safely and accurately perform the puncture in percutaneous nephrolithotomy.