2023
Autores
Zhao, DB; Ferdian, E; Talou, GDM; Quill, GM; Gilbert, K; Wang, VY; Gamage, TPB; Pedrosa, J; D'hooge, J; Sutton, TM; Lowe, BS; Legget, ME; Ruygrok, PN; Doughty, RN; Camara, O; Young, AA; Nash, MP;
Publicação
FRONTIERS IN CARDIOVASCULAR MEDICINE
Abstract
Segmentation of the left ventricle (LV) in echocardiography is an important task for the quantification of volume and mass in heart disease. Continuing advances in echocardiography have extended imaging capabilities into the 3D domain, subsequently overcoming the geometric assumptions associated with conventional 2D acquisitions. Nevertheless, the analysis of 3D echocardiography (3DE) poses several challenges associated with limited spatial resolution, poor contrast-to-noise ratio, complex noise characteristics, and image anisotropy. To develop automated methods for 3DE analysis, a sufficiently large, labeled dataset is typically required. However, ground truth segmentations have historically been difficult to obtain due to the high inter-observer variability associated with manual analysis. We address this lack of expert consensus by registering labels derived from higher-resolution subject-specific cardiac magnetic resonance (CMR) images, producing 536 annotated 3DE images from 143 human subjects (10 of which were excluded). This heterogeneous population consists of healthy controls and patients with cardiac disease, across a range of demographics. To demonstrate the utility of such a dataset, a state-of-the-art, self-configuring deep learning network for semantic segmentation was employed for automated 3DE analysis. Using the proposed dataset for training, the network produced measurement biases of -9 +/- 16 ml, -1 +/- 10 ml, -2 +/- 5 %, and 5 +/- 23 g, for end-diastolic volume, end-systolic volume, ejection fraction, and mass, respectively, outperforming an expert human observer in terms of accuracy as well as scan-rescan reproducibility. As part of the Cardiac Atlas Project, we present here a large, publicly available 3DE dataset with ground truth labels that leverage the higher resolution and contrast of CMR, to provide a new benchmark for automated 3DE analysis. Such an approach not only reduces the effect of observer-specific bias present in manual 3DE annotations, but also enables the development of analysis techniques which exhibit better agreement with CMR compared to conventional methods. This represents an important step for enabling more efficient and accurate diagnostic and prognostic information to be obtained from echocardiography.
2023
Autores
Salles, B; Cunha, J;
Publicação
2023 IEEE SYMPOSIUM ON VISUAL LANGUAGES AND HUMAN-CENTRIC COMPUTING, VL/HCC
Abstract
The architectural style of microservices has received much attention from both business and academia and converting a monolithic application into a microservice-based one has become a regular practice. However, companies struggle with migrating their existing monolithic applications to microservices and software engineers frequently face challenges due to a lack of awareness of alternative migration methodologies, making the migration process even harder. In this paper, we present a framework to help software engineers during the migration process by addressing gaps in understanding various migration tools and approaches, allowing for easy comparison between multiple options. Our tool combines multiple existing approaches into one platform, allowing a comprehensive visualization of migration proposals and comparing different options offered by already existing approaches.
2023
Autores
Pinto, AM; Marques, JVA; Abreu, N; Campos, DF; Pereira, MI; Gonçalves, E; Campos, HJ; Pereira, P; Neves, F; Matos, A; Govindaraj, S; Durand, L;
Publicação
OCEANS 2023 - LIMERICK
Abstract
The demonstration of robotic technologies in real environments is essential for technology developers and end-users to fully showcase the benefits of theirs solutions, and contributes to the promotion of the transition of inspection and maintenance methodologies towards automated robotic strategies. However, before allowing technologies to be demonstrated in real, operating offshore wind-farms, there is a need to de-risk the technology, to ensure its safe operation offshore. As part of the ATLANTIS project, a pioneer pilot infrastructure, the ATLANTIS Test Centre, was installed in Viana do Castelo, Portugal. This infrastructure will allow the demonstration of key enabling robotic technologies for offshore inspection and maintenance. The Test Centre is composed of two distinct testbeds, and a supervisory control centre, enabling the de-risking, testing, validation and demonstration of technologies, in both near-real and real environments. This paper presents the details of the Coastal Testbed of the ATLANTIS Test Centre, from implementation to available resources and infrastructures and environment details.
2023
Autores
de Sousa, JNC; Dias, TG; de Azevedo, MAN;
Publicação
INFRASTRUCTURES
Abstract
The public transport system is responsible for the displacement of a large part of the population, particularly in developing countries. This fact makes it relevant to evaluate the performance of public transport to provide an efficient and effective service. The purpose of this study is to conduct a performance evaluation of the public transport operation in the Metropolitan Region of Fortaleza (MRF), in the State of Ceara, Brazil. The analysis is based on DEA and the Malmquist index, based on three inputs (total operating time, fleet age, and the mileage traveled) and two outputs (fare revenue and number of passengers). Data were obtained through automated fare collection systems (AFCs) that were implemented in the MRF. Although there were no major fluctuations in performance during the analyzed period, the results indicate that the system's performance declined in certain years. In addition, the analysis enables a better understanding of route performance, considering the operating company or the area of operation, which helps to diagnose and comprehend the operation more effectively. By analyzing the operational performance over time, the proposed approach provides an additional contribution by offering a comprehensive overview to the involved stakeholders, fostering decision-making processes based on evidence.
2023
Autores
Torresan, C; Bernardes, G; Gaetano, E; Restivo, T;
Publicação
ARTSIT, INTERACTIVITY AND GAME CREATION, ARTSIT 2022
Abstract
Stress-ribbon footbridges are often prone to excessive vibrations induced by environmental phenomena (e.g., wind) and human actions (e.g., walking). This paper studies a stress-ribbon footbridge at the Faculty of Engineering of the University of Porto (FEUP) in Portugal, where different degrees of vertical vibrations are perceptible in response to human actions. We adopt sonification techniques to create a sonic manifestation that shows the footbridge’s dynamic response to human interaction. Two distinct sonification techniques – audification and parameter mapping – are adopted to provide intuitive access to the footbridge dynamics from low-level acceleration data and higher-level spectral analysis. In order to evaluate the proposed sonification techniques in exposing relevant information about human actions on the footbridge, an online perceptual test was conducted to assess the understanding of the three following dimensions: 1) the number of people interacting with the footbridge, 2) their walking speed, and 3) the steadiness of their pace. The online perceptual test was conducted with and without a short training phase. Results of n= 23 participants show that parameter mapping sonification is more effective in promoting an intuitive understating of the footbridge dynamics compared to audification. Furthermore, when exposed to a short training phase, the participants’ perception improved in identifying the correct dimensions.
2023
Autores
Carvalho, DN; Dani, S; Sotelo, CG; Perez Martin, RI; Reis, RL; Silva, TH; Gelinsky, M;
Publicação
BIOMEDICAL MATERIALS
Abstract
In the past decade, there has been significant progress in 3D printing research for tissue engineering (TE) using biomaterial inks made from natural and synthetic compounds. These constructs can aid in the regeneration process after tissue loss or injury, but achieving high shape fidelity is a challenge as it affects the construct's physical and biological performance with cells. In parallel with the growth of 3D bioprinting approaches, some marine-origin polymers have been studied due to their biocompatibility, biodegradability, low immunogenicity, and similarities to human extracellular matrix components, making them an excellent alternative to land mammal-origin polymers with reduced disease transmission risk and ethical concerns. In this research, collagen from shark skin, chitosan from squid pens, and fucoidan from brown algae were effectively blended for the manufacturing of an adequate biomaterial ink to achieve a printable, reproducible material with a high shape fidelity and reticulated using four different approaches (phosphate-buffered saline, cell culture medium, 6% CaCl2, and 5 mM Genipin). Materials characterization was composed by filament collapse, fusion behavior, swelling behavior, and rheological and compressive tests, which demonstrated favorable shape fidelity resulting in a stable structure without deformations, and interesting shear recovery properties around the 80% mark. Additionally, live/dead assays were conducted in order to assess the cell viability of an immortalized human mesenchymal stem cell line, seeded directly on the 3D printed constructs, which showed over 90% viable cells. Overall, the Roswell Park Memorial Institute cell culture medium promoted the adequate crosslinking of this biopolymer blend to serve the TE approach, taking advantage of its capacity to hamper pH decrease coming from the acidic biomaterial ink. While the crosslinking occurs, the pH can be easily monitored by the presence of the indicator phenol red in the cell culture medium, which reduces costs and time.
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