15 documents found, page 1 of 2
Patient-specific outcome simulation after surgical correction of Pectus Excavat...
Couto, Mafalda Araújo Seara; Fonseca, João Luís Gomes; Moreira, António Herculano Jesus; Henriques-Coelho, Tiago; Fonseca, Jaime C.Although minimally invasive Nuss procedure is frequently performed to correct Pectus Excavatum, the successful aesthetical outcome is not always ensured. Using the computed tomography (CT) data of six patients, high-quality surfaces of the anterior chest wall were generated, alongside with a personalized corrective-bar. Through finite element method (FEM), replicating the surgical procedure, a simulation of the...
Numerical analysis of the stress distribution in fillet welds and double fillet...
Neves, Francisco; Soares, Tiago; Pinho, A. C. Marques; Meireles, José F.Welding processes are extremely used in the metalworking industry all over the world. Sometimes the engineer has difficulties in finding solutions for the analytical calculation welded joints with eccentricity. In addition, calculations and analytical principles generally do not coincide with numerical results. In this work, analytically calculated stresses, are compared with numerical stresses for a double-fil...
Main frame structural optimization for power transformers in short circuit
Linhares, C.; Carneiro, V. H.; Meireles, José F.; Pinho, A. C. Marques; Mendes, H.Electric power market is a contemporary challenge, due to the permanent increase in energy distribution demands, suppliers of power transformers have to constantly improve their engineering solutions for the design of equipment that are able to adapt to this permanent evolution. A fundamental challenge is the research of structural components embedded in power transformers tank that are able to withstand loadin...
Smart design and manufacturing of power transformers tanks
Mendes, H.; Linhares, C. C.; Coutinho, C. P.; Tavares, S. M.O.; Teixeira, M.; Moura, J. P.A.; Novais, C.; Teixeira, R.; Pinho, A. C. MarquesIndustry is undergoing through noteworthy changes, where most of the methodologies and procedures are increasingly assisted by advanced information systems. In addition, the communications between the entire product chain have been progressively more effective, allowing to support better decisions in the early phases of the product development. This industrial change demands companies to rethink the planning, d...
A dual-modal CT/US kidney phantom model for image-guided percutaneous renal access
Fonseca, João Luís Gomes; Miranda, Alice Augusta Macedo; Morais, Pedro; Queirós, Sandro Filipe Monteiro; Pinho, A. C. Marques; Fonseca, Jaime C.Percutaneous renal access (PRA) is a crucial step in some minimally invasive kidney interventions. During this step, the surgeon inserts a needle through the skin until the kidney target site using fluoroscopy and ultrasound imaging. Recently, new concepts of enhanced image-guided interventions have been introduced in these interventions. However, their validation remains a challenging task. Phantom models have...
The intradiscal failure pressure on porcine lumbar intervertebral discs: an exp...
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques; Claro, José Carlos PimentaThe intervertebral disc is submitted to complex loading during its normal daily activities which are responsible for variations of the hydrostatic pressure in its structure. Thus, the determination of the magnitude of failure hydrostatic pressure is essential as a potential for the evaluation of the mechanisms that promote the weakening and the disruption of the annular fibers, commonly linked to herniation pro...
Comparison between the dynamic and initial creep response of porcine and human ...
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques; Claro, José Carlos PimentaThe study of mechanical properties of intervertebral disc (IVD) is important for the evaluation of disc implants. To determine these properties, several animal spine models were used. The goal of this work is to determine and compare the dynamic stiffness coefficient (K-d) and initial creep behavior of porcine intervertebral disc with the human ones. Porcine lumbar "motion segments" were subjected to 1200 cycle...
Voxel-based registration of simulated and real patient CBCT data for accurate d...
Moreira, António Herculano Jesus; Queirós, Sandro Filipe Monteiro; Morais, Pedro André Gonçalves; Rodrigues, Nuno F.; Correia, André RicardoThe success of dental implant-supported prosthesis is directly linked to the accuracy obtained during implant's pose estimation (position and orientation). Although traditional impression techniques and recent digital acquisition methods are acceptably accurate, a simultaneously fast, accurate and operator-independent methodology is still lacking. Hereto, an image-based framework is proposed to estimate the pat...
Quasi-static and dynamic properties of the intervertebral disc: experimental st...
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques; Claro, José Carlos PimentaPurpose: The study of axial loading is essential to determine the properties of intervertebral disc. The objectives of this work are (1) to quantify the mechanical properties of porcine lumbar intervertebral discs under static and cyclic compressive loading, and (2) to determine the parameters of a five-parameter rheological model for porcine and compare them with those obtained for human lumbar intervertebral ...
An electromagnetic tracker system for the design of a dental superstructure
Moreira, António Herculano Jesus; Queirós, Sandro Filipe Monteiro; Rodrigues, Nuno F.; Pinho, A. C. Marques; Fonseca, Jaime C.; Vilaça, João L.Nowadays, different techniques are available for manufacturing full-arch implant-supported prosthesis, many of them based on an impression procedure. Nevertheless, the long-term success of the prosthesis is highly influenced by the accuracy during such process, being affected by factors such as the impression material, implant position, angulation and depth. This paper investigates the feasibility of a 3D elect...