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Publications

Publications by BIO

2018

Wearable biomonitoring platform for the assessment of stress and its impact on cognitive performance of firefighters: An experimental study

Authors
Rodrigues, S; Paiva, JS; Dias, D; Pimentel, G; Kaiseler, M; Cunha, JPS;

Publication
Clinical Practice and Epidemiology in Mental Health

Abstract
Background: Stress is a complex process with an impact on health and performance. The use of wearable sensor-based monitoring systems offers interesting opportunities for advanced health care solutions for stress analysis. Considering the stressful nature of firefighting and its importance for the community’s safety, this study was conducted for firefighters. Objectives: A biomonitoring platform was designed, integrating different biomedical systems to enable the acquisition of real time Electrocardiogram (ECG), computation of linear Heart Rate Variability (HRV) features and collection of perceived stress levels. This platform was tested using an experimental protocol, designed to understand the effect of stress on firefighter’s cognitive performance, and whether this effect is related to the autonomic response to stress. Method: The Trier Social Stress Test (TSST) was used as a testing platform along with a 2-Choice Reaction Time Task. Linear HRV features from the participants were acquired using an wearable ECG. Self-reports were used to assess perceived stress levels. Results: The TSST produced significant changes in some HRV parameters (AVNN, SDNN and LF/HF) and subjective measures of stress, which recovered after the stress task. Although these short-term changes in HRV showed a tendency to normalize, an impairment on cognitive performance was found after performing the stress event. Conclusion: Current findings suggested that stress compromised cognitive performance and caused a measurable change in autonomic balance. Our wearable biomonitoring platform proved to be a useful tool for stress assessment and quantification. Future studies will implement this biomonitoring platform for the analysis of stress in ecological settings. © 2018 Rodrigues et al.

2018

Classification of Breast Cancer Histology Images Through Transfer Learning Using a Pre-trained Inception Resnet V2

Authors
Ferreira, CA; Melo, T; Sousa, P; Meyer, MI; Shakibapour, E; Costa, P; Campilho, A;

Publication
Image Analysis and Recognition - 15th International Conference, ICIAR 2018, Póvoa de Varzim, Portugal, June 27-29, 2018, Proceedings

Abstract
Breast cancer is one of the leading causes of female death worldwide. The histological analysis of breast tissue allows for the differentiation of the tissue suspected to be abnormal into four classes: normal tissue, benign tumor, in situ carcinoma and invasive carcinoma. Automatic diagnostic systems can help in that task. In this sense, this work propose a deep neural network approach using transfer learning to classify breast cancer histology images. First, the added top layers are trained and a second fine-tunning is done on some feature extraction layers that are frozen previously. The used network is an Inception Resnet V2. In order to overcome the lack of data, data augmentation is performed too. This work is a suggested solution for the ICIAR 2018 BACH-Challenge and the accuracy is 0.76 in the blind test set. © 2018, Springer International Publishing AG, part of Springer Nature.

2018

Agent-based model of diffusion of N-acyl homoserine lactones in a multicellular environment of Pseudomonas aeruginosa and Candida albicans

Authors
Perez Rodriguez, G; Dias, S; Perez Perez, M; Fdez Riverola, F; Azevedo, NF; Lourenco, A;

Publication
BIOFOULING

Abstract
Experimental incapacity to track microbe-microbe interactions in structures like biofilms, and the complexity inherent to the mathematical modelling of those interactions, raises the need for feasible, alternative modelling approaches. This work proposes an agent-based representation of the diffusion of N-acyl homoserine lactones (AHL) in a multicellular environment formed by Pseudomonas aeruginosa and Candida albicans. Depending on the spatial location, C. albicans cells were variably exposed to AHLs, an observation that might help explain why phenotypic switching of individual cells in biofilms occurred at different time points. The simulation and algebraic results were similar for simpler scenarios, although some statistical differences could be observed (p<0.05). The model was also successfully applied to a more complex scenario representing a small multicellular environment containing C. albicans and P. aeruginosa cells encased in a 3-D matrix. Further development of this model may help create a predictive tool to depict biofilm heterogeneity at the single-cell level.

2018

The development of an automatic tool to improve perforators detection in Angio CT in DIEAP flap breast reconstruction

Authors
Mavioso, C; Correia Anacleto, JC; Vasconcelos, MA; Araujo, R; Oliveira, H; Pinto, D; Gouveia, P; Alves, C; Cardoso, F; Cardoso, J; Cardoso, MJ;

Publication
EUROPEAN JOURNAL OF CANCER

Abstract

2018

Deep Homography Based Localization on Videos of Endoscopic Capsules

Authors
Pinheiro, G; Coelho, P; Salgado, M; Oliveira, HP; Cunha, A;

Publication
PROCEEDINGS 2018 IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOMEDICINE (BIBM)

Abstract
Endoscopic capsules are vitamin-sized devices that create 8 to 10 hour videos of the digestive tract. They are the leading diagnosing method for the small bowel, a region not easily accessible with traditional endoscopy techniques. However, these capsules do not provide localization information, even though it is crucial for the diagnosis, follow-ups and surgical interventions. Currently, the capsule localization is either estimated based on scarce gastrointestinal tract landmarks or given by additional hardware that causes discomfort to the patient and represents a cost increase. Current software methods show great potential, but still need to improve in order to overcome their limitations. In this work, a visual odometry method for capsule localization inside the small bowel is proposed.

2018

The value of 3D images in the aesthetic evaluation of breast cancer conservative treatment. Results from a prospective multicentric clinical trial

Authors
Cardoso, MJ; Vrieling, C; Cardoso, JS; Oliveira, HP; Williams, NR; Dixon, JM; Gouveia, P; Keshtgar, M; Mosahebi, A; Bishop, D; Lacher, R; Liefers, GJ; Molenkamp, B; Van de Velde, C; Azevedo, I; Canny, R; Christie, D; Evans, A; Fitzal, F; Graham, P; Hamdi, M; Joahensen, J; Laws, S; Merck, B; Reece, G; Sacchini, V; Vrancken, MJ; Wilkinson, L; Matthes, GZ;

Publication
BREAST

Abstract
Purpose: BCCT.core (Breast Cancer Conservative Treatment. cosmetic results) is a software created for the objective evaluation of aesthetic result of breast cancer conservative treatment using a single patient frontal photography. The lack of volume information has been one criticism, as the use of 3D information might improve accuracy in aesthetic evaluation. In this study, we have evaluated the added value of 3D information to two methods of aesthetic evaluation: a panel of experts; and an augmented version of the computational model - BCCT.core3d. Material and methods: Within the scope of EU Seventh Framework Programme Project PICTURE, 2D and 3D images from 106 patients from three clinical centres were evaluated by a panel of 17 experts and the BCCT.core. Agreement between all methods was calculated using the kappa (K) and weighted kappa (wK) statistics. Results: Subjective agreement between 2D and 3D individual evaluation was fair to moderate. The agreement between the expert classification and the BCCT.core software with both 2D and 3D features was also fair to moderate. Conclusions: The inclusion of 3D images did not add significant information to the aesthetic evaluation either by the panel or the software. Evaluation of aesthetic outcome can be performed using of the BCCT.core software, with a single frontal image.

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