João Valente
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
João Valente has a total of 35 co-authors. Here are the top co-authors by number of shared publications:
- Ana Fred
Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
3 shared publications - Ernesto Filgueiras
Universidade de Lisboa | UBI Polo
3 shared publications - Eulerson Rodrigues
University of Beira Interior
3 shared publications - Hugo Plácido da Silva
Instituto de Telecomunicações, Instituto Superior Técnico, 1049-001 Lisbon, Portugal
3 shared publications - Carlos Santo Lima
Department of Industrial Electronics, University of Minho, 4800-058 Guimarães, Portugal
2 shared publications - Pedro Miguel Vieira
CMEMS-UMinho Research Unit, University of Minho, Guimarães, PORTUGAL
2 shared publications
Latest Publications
- 11 June 2024
- Published by Springer Nature
- p. 61-78
Exploring Virtual Proximity in Sensory Food Experience
- 11 June 2024
- Published by Springer Nature
- p. 61-78
Exploring Virtual Proximity in Sensory Food Experience
- 9 July 2023
- Published by Springer Nature
- p. 317-332
Physiological Analysis of Spectator Engagement in Counter Strike: Global Offensive
- 9 July 2023
- Published by Springer Nature
- p. 317-332
Physiological Analysis of Spectator Engagement in Counter Strike: Global Offensive
- 1 January 2022
- Published by Elsevier in Applied Soft Computing
- Vol. 115
A dissimilarity-based approach to automatic classification of biosignal modalities
- 1 January 2022
- Published by Elsevier in Applied Soft Computing
- Vol. 115
A dissimilarity-based approach to automatic classification of biosignal modalities
- 27 September 2021
- Published by Taylor & Francis
- p. 36-55
BrainAnswer platform
Remote monitoring tools are promising methodological options to ensure point-of-care vigilance and assist on clinical decision making in quite diverse clinical contexts. Such approach has been acknowledged as a particularly important asset when applied in the old adult population, as it contributes to a feeling of safety and trust, thus motivating the old adult to persecute independent living and promoting well-being. In this chapter we present a technological platform designed for remote monitoring of the old adult, discussing its usefulness in an applied case study.
- 27 September 2021
- Published by Taylor & Francis
- p. 36-55
BrainAnswer platform
Remote monitoring tools are promising methodological options to ensure point-of-care vigilance and assist on clinical decision making in quite diverse clinical contexts. Such approach has been acknowledged as a particularly important asset when applied in the old adult population, as it contributes to a feeling of safety and trust, thus motivating the old adult to persecute independent living and promoting well-being. In this chapter we present a technological platform designed for remote monitoring of the old adult, discussing its usefulness in an applied case study.
- Open Access
Neuroorganoleptics: Organoleptic Testing Based on Psychophysiological Sensing
There is an increasing interest, in consumer behaviour research related to food and beverage, in taking a step further from the traditional self-report questionnaires and organoleptic properties assessment. With the growing availability of psychophysiological data acquisition devices, and advancements in the study of the underlying signal sources seeking affective state assessment, the use of psychophysiological data analysis is a natural evolution in organoleptic testing. In this paper we propose a protocol for what can be defined as neuroorganoleptic analysis, a method that combines traditional approaches with psychophysiological data acquired during sensory testing. Our protocol was applied to a case study project named MobFood, where four samples of food were tested by a total of 83 participants, using preference and acceptance tasks, across three different sessions. Best practices and lessons learned regarding the laboratory setting and the acquisition of psychophysiological data were derived from this case study, which are herein described. Preliminary results show that certain Heart Rate Variability (HRV) features have a strong correlation with the preferences self-reported by the participants.
Open AccessNeuroorganoleptics: Organoleptic Testing Based on Psychophysiological Sensing
There is an increasing interest, in consumer behaviour research related to food and beverage, in taking a step further from the traditional self-report questionnaires and organoleptic properties assessment. With the growing availability of psychophysiological data acquisition devices, and advancements in the study of the underlying signal sources seeking affective state assessment, the use of psychophysiological data analysis is a natural evolution in organoleptic testing. In this paper we propose a protocol for what can be defined as neuroorganoleptic analysis, a method that combines traditional approaches with psychophysiological data acquired during sensory testing. Our protocol was applied to a case study project named MobFood, where four samples of food were tested by a total of 83 participants, using preference and acceptance tasks, across three different sessions. Best practices and lessons learned regarding the laboratory setting and the acquisition of psychophysiological data were derived from this case study, which are herein described. Preliminary results show that certain Heart Rate Variability (HRV) features have a strong correlation with the preferences self-reported by the participants.
- 3 July 2021
- Published by Springer Nature
- p. 371-383
Behavioral Analysis of eSports Spectators: A Research Proposal
- 3 July 2021
- Published by Springer Nature
- p. 371-383
Behavioral Analysis of eSports Spectators: A Research Proposal
- Open Access
e-CoVig: A Novel mHealth System for Remote Monitoring of Symptoms in COVID-19
In 2019, a new virus, SARS-CoV-2, responsible for the COVID-19 disease, was discovered. Asymptomatic and mildly symptomatic patients were forced to quarantine and closely monitor their symptoms and vital signs, most of the time at home. This paper describes e-CoVig, a novel mHealth application, developed as an alternative to the current monitoring paradigm, where the patients are followed up by direct phone contact. The e-CoVig provides a set of functionalities for remote reporting of symptoms, vital signs, and other clinical information to the health services taking care of these patients. The application is designed to register and transmit the heart rate, blood oxygen saturation (), body temperature, respiration, and cough. The system features a mobile application, a web/cloud platform, and a low-cost specific device to acquire the temperature and . The architecture of the system is flexible and can be configured for different operation conditions. Current commercial devices, such as oximeters and thermometers, can also be used and read using the optical character recognition (OCR) functionality of the system. The data acquired at the mobile application are sent automatically to the web/cloud application and made available in real-time to the medical staff, enabling the follow-up of several users simultaneously without the need for time consuming phone call interactions. The system was already tested for its feasibility and a preliminary deployment was performed on a nursing home showing promising results.Open Accesse-CoVig: A Novel mHealth System for Remote Monitoring of Symptoms in COVID-19
In 2019, a new virus, SARS-CoV-2, responsible for the COVID-19 disease, was discovered. Asymptomatic and mildly symptomatic patients were forced to quarantine and closely monitor their symptoms and vital signs, most of the time at home. This paper describes e-CoVig, a novel mHealth application, developed as an alternative to the current monitoring paradigm, where the patients are followed up by direct phone contact. The e-CoVig provides a set of functionalities for remote reporting of symptoms, vital signs, and other clinical information to the health services taking care of these patients. The application is designed to register and transmit the heart rate, blood oxygen saturation (), body temperature, respiration, and cough. The system features a mobile application, a web/cloud platform, and a low-cost specific device to acquire the temperature and . The architecture of the system is flexible and can be configured for different operation conditions. Current commercial devices, such as oximeters and thermometers, can also be used and read using the optical character recognition (OCR) functionality of the system. The data acquired at the mobile application are sent automatically to the web/cloud application and made available in real-time to the medical staff, enabling the follow-up of several users simultaneously without the need for time consuming phone call interactions. The system was already tested for its feasibility and a preliminary deployment was performed on a nursing home showing promising results. - 1 October 2020
- Published by Elsevier in Computer Methods and Programs in Biomedicine
- Vol. 195, 105675
Morphological autoencoders for apnea detection in respiratory gating radiotherapy
- 1 October 2020
- Published by Elsevier in Computer Methods and Programs in Biomedicine
- Vol. 195, 105675
Morphological autoencoders for apnea detection in respiratory gating radiotherapy
- 12 July 2019
- Published by Wiley in Medical Physics
- Vol. 47 (1) , 52-63
Automatic detection of small bowel tumors in wireless capsule endoscopy images using ensemble learning
Purpose: Wireless Capsule Endoscopy (WCE) is a minimally invasive diagnosis tool for lesion detection in the gastrointestinal tract, reaching places where conventional endoscopy is unable to. However, the significant amount of acquired data leads to difficulties in the diagnosis by the physicians; which can be eased with computer assistance. This paper addresses a method for the automatic detection of tumors in WCE by using a two‐step based procedure: region of interest selection and classification.Methods: The first step aims to separate abnormal from normal tissue by using automatic segmentation based on a Gaussian Mixture Model (GMM). A modified version of the Anderson method for convergence acceleration of the expectation–maximization (EM) algorithm is proposed. The proposed features for both segmentation and classification are based on the CIELab color space, as a way of bypassing lightness variations, where theLcomponent is discarded. Tissue variability among subjects, light inhomogeneities and even intensity differences among different devices can be overcome by using simultaneously features from both regions. In the second step, an ensemble system with partition of the training data with a new training scheme is proposed. At this stage, the gating network is trained after the experts have been trained decoupling the joint maximization of both modules. The partition module is also used at the test step, leading the incoming data to the most likely expert allowing incremental adaptation by preserving data diversity.Results: This algorithm outperforms others based on texture features selected from Wavelets and Curvelets transforms, classified by a regular support vector machine (SVM) in more than 5%.Conclusions: This work shows that simpler features can outperform more elaborate ones if appropriately designed. In the current case, luminance was discarded to cope with saturated tissue, facilitating the color perception. Ensemble systems remain an open research field. In the current case, changes in both topology and training strategy have led to significant performance improvements. A system with this level of performance can be used in current clinical practice.
- 12 July 2019
- Published by Wiley in Medical Physics
- Vol. 47 (1) , 52-63
Automatic detection of small bowel tumors in wireless capsule endoscopy images using ensemble learning
Purpose: Wireless Capsule Endoscopy (WCE) is a minimally invasive diagnosis tool for lesion detection in the gastrointestinal tract, reaching places where conventional endoscopy is unable to. However, the significant amount of acquired data leads to difficulties in the diagnosis by the physicians; which can be eased with computer assistance. This paper addresses a method for the automatic detection of tumors in WCE by using a two‐step based procedure: region of interest selection and classification.Methods: The first step aims to separate abnormal from normal tissue by using automatic segmentation based on a Gaussian Mixture Model (GMM). A modified version of the Anderson method for convergence acceleration of the expectation–maximization (EM) algorithm is proposed. The proposed features for both segmentation and classification are based on the CIELab color space, as a way of bypassing lightness variations, where theLcomponent is discarded. Tissue variability among subjects, light inhomogeneities and even intensity differences among different devices can be overcome by using simultaneously features from both regions. In the second step, an ensemble system with partition of the training data with a new training scheme is proposed. At this stage, the gating network is trained after the experts have been trained decoupling the joint maximization of both modules. The partition module is also used at the test step, leading the incoming data to the most likely expert allowing incremental adaptation by preserving data diversity.Results: This algorithm outperforms others based on texture features selected from Wavelets and Curvelets transforms, classified by a regular support vector machine (SVM) in more than 5%.Conclusions: This work shows that simpler features can outperform more elaborate ones if appropriately designed. In the current case, luminance was discarded to cope with saturated tissue, facilitating the color perception. Ensemble systems remain an open research field. In the current case, changes in both topology and training strategy have led to significant performance improvements. A system with this level of performance can be used in current clinical practice.
- 1 February 2018
- Published by Elsevier in Journal of Neuroscience Methods
- Vol. 295, 129-138
Brain extraction in partial volumes T2*@7T by using a quasi-anatomic segmentation with bias field correction
- 1 February 2018
- Published by Elsevier in Journal of Neuroscience Methods
- Vol. 295, 129-138
Brain extraction in partial volumes T2*@7T by using a quasi-anatomic segmentation with bias field correction