Federico Guede-Fernández

Dr. Federico Guede-Fernández

FCT - UNL
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 June 2019 in IEEE Access
Verified
Journal Article
Open access
Federico Guede-FernándezFederico Guede-Fernández
Federico Guede-Fernández
MFMireya Fernandez-Chimeno
Mireya Fernandez-Chimeno
JRJuan Ramos-Castro
Juan Ramos-Castro
MGMiguel A. Garcia-Gonzalez
Miguel A. Garcia-Gonzalez
Drowsy driving is a prevalent and serious public health issue that deserves attention. Recent studies estimate around 20% of car crashes have been caused by drowsy drivers. Nowadays, one of the main goals in the development of new advanced driver assistance systems is the trustworthy drowsiness detection. In this paper, a drowsiness detection method based on changes in the respiratory signal is proposed. The respiratory signal, which has been obtained using an inductive plethysmography belt, has been processed in real-time in order to classify the driver’s state of alertness as drowsy or awake. The proposed algorithm is based on the analysis of the respiratory rate variability (RRV) in order to detect the fight against to fall asleep. Moreover, a method to provide a quality level of the respiratory signal is also proposed. Both methods have been combined to reduce false alarms due to changes of measured RRV associated not to drowsiness but body movements. A driving simulator cabin has been used to perform the validation tests and external observers have rated the drivers’ state of alertness in order to evaluate the algorithm performance. It has been achieved a specificity of 96.6%, sensitivity of 90.3% and Cohen’s Kappa agreement score of 0.75 on average across all subjects through a leave-one-subject-out cross-validation. A novel algorithm for driver’s state of alertness monitoring through the identification of the fight against to fall asleep has been validated. The proposed algorithm may be a valuable vehicle safety system to alert drowsiness while driving.

17 October 2021 in Fire
Verified
Journal Article
Open access
PDF file
Federico Guede-FernándezFederico Guede-Fernández
Federico Guede-Fernández
Leonardo MartinsLeonardo Martins
Leonardo Martins
Rui Valente de AlmeidaRui Valente de Almeida
Rui Valente de Almeida
Hugo GamboaHugo Gamboa
Hugo Gamboa
PVPedro M. Vieira
Pedro M. Vieira
Forest fires are still a large concern in several countries due to the social, environmental and economic damages caused. This paper aims to show the design and validation of a proposed system for the classification of smoke columns with object detection and a deep learning-based approach. This approach is able to detect smoke columns visible below or above the horizon. During the dataset labelling, the smoke object was divided into three different classes, depending on its distance to the horizon, a cloud object was also added, along with images without annotations. A comparison between the use of RetinaNet and Faster R-CNN was also performed. Using an independent test set, an F1-score around 80%, a G-mean around 80% and a detection rate around 90% were achieved by the two best models: both were trained with the dataset labelled with three different smoke classes and with augmentation; Faster R-CNNN was the model architecture, re-trained during the same iterations but following different learning rate schedules. Finally, these models were tested in 24 smoke sequences of the public HPWREN dataset, with 6.3 min as the average time elapsed from the start of the fire compared to the first detection of a smoke column.

1 March 2020 in Biomedical Signal Processing and Control
Verified
Journal Article
Closed access
Federico Guede-FernándezFederico Guede-Fernández
Federico Guede-Fernández
VFVíctor Ferrer-Mileo
Víctor Ferrer-Mileo
MMMarc Mateu-Mateus
Marc Mateu-Mateus
JRJuan Ramos-Castro
Juan Ramos-Castro
MGMiguel Ángel García-González
Miguel Ángel García-González
MFMireya Fernández-Chimeno
Mireya Fernández-Chimeno

EOEduarda Oliosi
Eduarda Oliosi
Federico Guede-FernándezFederico Guede-Fernández
Federico Guede-Fernández
ALAna Londral
Ana Londral
Frailty characterizes a state of impairments that increases the risk of adverse health outcomes such as physical limitation, lower quality of life, and premature death. Frailty prevention, early screening, and management of potential existing conditions are essential and impact the elderly population positively and on society. Advanced machine learning (ML) processing methods are one of healthcare’s fastest developing scientific and technical areas. Although research studies are being conducted in a controlled environment, their translation into the real world (clinical setting, which is often dynamic) is challenging. This paper presents a narrative review of the procedures for the frailty screening applied to the innovative tools, focusing on indicators and ML approaches. It results in six selected studies. Support vector machine was the most often used ML method. These methods apparently can identify several risk factors to predict pre-frail or frailty. Even so, there are some limitations (e.g., quality data), but they have enormous potential to detect frailty early.

1 August 2015
Verified
Conference Paper
Closed access
Federico Guede-FernándezFederico Guede-Fernández
Federico Guede-Fernández
VFV. Ferrer-Mileo
V. Ferrer-Mileo
JCJuan Ramos Castro
Juan Ramos Castro
MFM. Fernandez-Chimeno
M. Fernandez-Chimeno
MGM. A. Garcia-Gonzalez
M. A. Garcia-Gonzalez
The aim of this paper is to present a smartphone based system for real-time pulse-to-pulse (PP) interval time series acquisition by frame-to-frame camera image processing. The developed smartphone application acquires image frames from built-in rear-camera at the maximum available rate (30 Hz) and the smartphone GPU has been used by Renderscript API for high performance frame-by-frame image acquisition and computing in order to obtain PPG signal and PP interval time series. The relative error of mean heart rate is negligible. In addition, measurement posture and the employed smartphone model influences on the beat-to-beat error measurement of heart rate and HRV indices have been analyzed. Then, the standard deviation of the beat-to-beat error (SDE) was 7.81 ± 3.81 ms in the worst case. Furthermore, in supine measurement posture, significant device influence on the SDE has been found and the SDE is lower with Samsung S5 than Motorola X. This study can be applied to analyze the reliability of different smartphone models for HRV assessment from real-time Android camera frames processing.

4 June 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Leonardo MartinsLeonardo Martins
Leonardo Martins
Federico Guede-FernándezFederico Guede-Fernández
Federico Guede-Fernández
Rui Valente de AlmeidaRui Valente de Almeida
Rui Valente de Almeida
Hugo GamboaHugo Gamboa
Hugo Gamboa
PVPedro M. Vieira
Pedro M. Vieira
Governmental offices are still highly concerned with controlling the escalation of forest fires due to their social, environmental and economic consequences. This paper presents new developments to a previously implemented system for the classification of smoke columns with object detection and a deep learning-based approach. The study focuses on identifying and correcting several False Positive cases while only obtaining a small reduction of the True Positives. Our approach was based on using an instance segmentation algorithm to obtain the shape, color and spectral features of the object. An ensemble of Machine Learning (ML) algorithms was then used to further identify smoke objects, obtaining a removal of around 95% of the False Positives, with a reduction to 88.7% (from 93.0%) of the detection rate on 29 newly acquired daily sequences. This model was also compared with 32 smoke sequences of the public HPWREN dataset and a dataset of 75 sequences attaining 9.6 and 6.5 min, respectively, for the average time elapsed from the fire ignition and the first smoke detection.