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Publications

2025

Assisted Vascular Analysis (AVA) for Deep Inferior Epigastric Perforators: Pipeline Analysis

Authors
Ferreira, R; Silva, J; Romariz, M; Pinto, D; Araújo, RJ; Santinha, J; Gouveia, P; Oliveira, HP;

Publication
BIBE

Abstract
Algorithms based on computer vision are commonly used in pre-operative procedures to help health professionals detecting blood vessels, which is also the case with the Deep Inferior Epigastric Perforators (DIEPs). These blood vessels are essential to produce a viable autologous DIEP flap, and the analysis of characteristics such as their location, diameter and course is essential to ensure the success of surgeries. This analysis is made by a team of radiology technicians and then validated by a surgeon, making it a complex process that can take up to 2 hours. The proposed algorithm called Assisted Vascular Analysis (AVA) was developed to ensure a faster alternative to the conventional methods, using automation to identify structures of interest such as the skin, umbilicus and fascia, while also requiring minimum input from the user to segment each DIEP (2 points for the subcutaneous portion and 2 for the intramuscular portion). The AVA feasibility tests where conducted using 6 Computed Tomography Angiographies (CTAs), with a total of 28 DIEP calibers obtained during surgery (ground truths) from patients that underwent breast reconstruction with a DIEP flap. The algorithm was evaluated for its capability to segment the DIEPs and measure their caliber, comparing the results with the ground truth calibers and the manual mapping done by the radiology technicians. The Root Mean Square Error (RMSE) metric shows that the calibers obtained by the AVA algorithm (0.57 millimeters) and the radiology technicians (0.46 millimeters) are very similar, with the radiology technicians gaining a smaller edge of 0.11 millimeters. These results are very promising, since the errors are inferior to the average image resolution (0.88 millimeters). It was also demonstrated that the AVA algorithm is a faster alternative to manual segmentation, taking around 10 minutes to fully analyze each CTA, while the radiology technicians takes around 1 hour to do the DIEP mapping and caliber measurements. In conclusion, AVA is a validated algorithm to segment DIEP vessels and a faster alternative compared with conventional methods. © 2025 IEEE.

2025

Adherence, acceptability, and usability of a smartphone app to promote physical exercise in patients with peripheral arterial disease and intermittent claudication

Authors
Oliveira, R; Pedras, S; Veiga, C; Moreira, L; Santarem, D; Guedes, D; Paredes, H; Silva, I;

Publication
INFORMATICS FOR HEALTH & SOCIAL CARE

Abstract
This study presents the development and assessment of a mobile application - the WalkingPAD app - aimed at promoting adherence to physical exercise among patients with Peripheral Arterial Disease (PAD). The assessment of adherence, acceptability, and usability was performed using mixed methods. Thirty-eight patients participated in the study with a mean age of 63.4 years (SD = 6.8). Thirty patients used the application for three months, responded to a semi-structured interview, and completed a task test and the System Usability Scale (SUS, ranging from 0 to 100). The application's adherence rate was 73%. When patients were asked about their reasons for using the app, the main themes that emerged were motivation, self-monitoring, and support in fulfilling a commitment. The average SUS score was 82.82 (SD = 18.4), indicating high usability. An upcoming version of the WalkingPAD app is expected to redesign both tasks - opening the app and looking up the walking history - which were rated as the most difficult tasks to accomplish. The new version of the WalkingPAD app will incorporate participants' comments and suggestions to enhance usability for this population.

2025

Second FRCSyn-onGoing: Winning solutions and post-challenge analysis to improve face recognition with synthetic data

Authors
DeAndres Tame, I; Tolosana, R; Melzi, P; Vera Rodriguez, R; Kim, M; Rathgeb, C; Liu, XM; Gomez, LF; Morales, A; Fierrez, J; Ortega Garcia, J; Zhong, ZZ; Huang, YG; Mi, YX; Ding, SH; Zhou, SG; He, S; Fu, LZ; Cong, H; Zhang, RY; Xiao, ZH; Smirnov, E; Pimenov, A; Grigorev, A; Timoshenko, D; Asfaw, KM; Low, CY; Liu, H; Wang, CY; Zuo, Q; He, ZX; Shahreza, HO; George, A; Unnervik, A; Rahimi, P; Marcel, S; Neto, PC; Huber, M; Kolf, JN; Damer, N; Boutros, F; Cardoso, JS; Sequeira, AF; Atzori, A; Fenu, G; Marras, M; Struc, V; Yu, J; Li, ZJ; Li, JC; Zhao, WS; Lei, Z; Zhu, XY; Zhang, XY; Biesseck, B; Vidal, P; Coelho, L; Granada, R; Menotti, D;

Publication
INFORMATION FUSION

Abstract
Synthetic data is gaining increasing popularity for face recognition technologies, mainly due to the privacy concerns and challenges associated with obtaining real data, including diverse scenarios, quality, and demographic groups, among others. It also offers some advantages over real data, such as the large amount of data that can be generated or the ability to customize it to adapt to specific problem-solving needs. To effectively use such data, face recognition models should also be specifically designed to exploit synthetic data to its fullest potential. In order to promote the proposal of novel Generative AI methods and synthetic data, and investigate the application of synthetic data to better train face recognition systems, we introduce the 2nd FRCSyn-onGoing challenge, based on the 2nd Face Recognition Challenge in the Era of Synthetic Data (FRCSyn), originally launched at CVPR 2024. This is an ongoing challenge that provides researchers with an accessible platform to benchmark (i) the proposal of novel Generative AI methods and synthetic data, and (ii) novel face recognition systems that are specifically proposed to take advantage of synthetic data. We focus on exploring the use of synthetic data both individually and in combination with real data to solve current challenges in face recognition such as demographic bias, domain adaptation, and performance constraints in demanding situations, such as age disparities between training and testing, changes in the pose, or occlusions. Very interesting findings are obtained in this second edition, including a direct comparison with the first one, in which synthetic databases were restricted to DCFace and GANDiffFace.

2025

EVLearn: extending the cityLearn framework with electric vehicle simulation

Authors
Fonseca, T; Ferreira, LL; Cabral, B; Severino, R; Nweye, K; Ghose, D; Nagy, Z;

Publication
Energy Inform.

Abstract
Intelligent energy management strategies, such as Vehicle-to-Grid (V2G) and Grid-to-Vehicle (V1G) emerge as a potential solution to the Electric Vehicles’ (EVs) integration into the energy grid. These strategies promise enhanced grid resilience and economic benefits for both vehicle owners and grid operators. Despite the announced perspective, the adoption of these strategies is still hindered by an array of operational problems. Key among these is the lack of a simulation platform that allows to validate and refine V2G and V1G strategies. Including the development, training, and testing in the context of Energy Communities (ECs) incorporating multiple flexible energy assets. Addressing this gap, first we introduce the EVLearn, an open-source extension for the existing CityLearn simulation framework. EVLearn provides both V2G and V1G energy management simulation capabilities into the study of broader energy management strategies of CityLearn by modeling EVs, their charging infrastructure and associated energy flexibility dynamics. Results validated the extension of CityLearn, where the impact of these strategies is highlighted through a comparative simulation scenario. © The Author(s) 2025.

2025

Integrating artificial intelligence into scenario analysis: a validated framework for strategic planning under economic uncertainty

Authors
Bessa, G; Barbosa, B;

Publication
Global Economics Research

Abstract

2025

Dynamic incentives for electric vehicles charging at supermarket stations: Causal insights on demand flexibility

Authors
Silva, CAM; Andrade, JR; Ferreira, A; Gomes, A; Bessa, RJ;

Publication
ENERGY

Abstract
Electric vehicles (EVs) are crucial in achieving a low-carbon transportation sector and can inherently offer demand-side flexibility by responding to price signals and incentives, yet real-world strategies to influence charging behavior remain limited. This paper combines bilevel optimization and causal machine learning as complementary tools to design and evaluate dynamic incentive schemes as part of a pilot project using a supermarket's EV charging station network. The bilevel model determines discount levels, while double machine learning quantifies the causal impact of these incentives on charging demand. The results indicate a marginal increase of 1.16 kW in charging demand for each one-percentage-point increase in discount. User response varies by hour and weekday, revealing treatment effect heterogeneity, insights that can inform business decision-making. While the two methods are applied independently, their combined use provides a framework for connecting optimization-based incentive design with data-driven causal evaluation. By isolating the impact of incentives from other drivers, the study sheds light on the potential of incentives to enhance demand-side flexibility in the electric mobility ecosystem.

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