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About

About

Luís Coelho has a degree and MsC in Electronics Engineering, at the Faculty of Engineering of Porto University, since 2000 and 2005 respectively. In 2012 he was awarded with the international PhD degree, in Telecommunications and Signal Processing from the University of Vigo, Spain. In 2001 he began teaching at Polytechnic Institute of Setubal, being in charge of the algorithms, data structures and computer programming courses, for desktop and web. In 2004 he moved to the Polytechnic Institute of Porto, the largest in Portugal, where he mainly teaches signal and image processing courses. He has been involved with the coordination of the Biomedical Engineering degree and master and of the Healthcare Management course. He is/was involved in several national and international projects and has supervised more than 200 internships with private companies in national and international context. He has also worked as a consultant at Microsoft Portugal contributing with knowledge and experience in signal processing related projects. As a researcher he has published more than 90 scientific articles in conferences and journals. He actively collaborates with the scientific community as participant, reviewer, organizer of scientific conferences or as journal editor. He has research interest on image and signal processing, human-machine interaction and healthcare management.

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Details

Details

  • Name

    Luis Coelho
  • Role

    Senior Researcher
  • Since

    10th February 2023
001
Publications

2024

Vision Robotics for the Automatic Assessment of the Diabetic Foot

Authors
Mesquita R.; Costa T.; Coelho L.; Silva M.F.;

Publication
Lecture Notes in Mechanical Engineering

Abstract
Diabetes, a chronic condition affecting millions of people, requires ongoing medical care and treatment, which can place a significant financial burden on society, directly and indirectly. In this paper we propose a vision-robotics system for the automatic assessment of the diabetic foot, one the exams used for the disease management. We present and discuss various computer vision techniques that can support the core operation of the system. U-Net and Segnet, two popular convolutional network architectures for image segmentation are applied in the current case. Hardcoded and machine learning pipelines are explained and compared using different metrics and scenarios. The obtained results show the advantages of the machine learning approach but also point to the importance of hard coded rules, especially when well know areas, such as the human foot, are the systems’ target. Overall, the system achieved very good results, paving the way to a fully automated clinical system.

2024

Advancing the understanding of pupil size variation in occupational safety and health: A systematic review and evaluation of open-source methodologies

Authors
Ferreira, F; Ferreira, S; Mateus, C; Barbosa-Rocha, N; Coelho, L; Rodrigues, MA;

Publication
SAFETY SCIENCE

Abstract
Pupil size can be used as an important biomarker for occupational risks. In recent years, there has been an increase in the development of open-source tools dedicated to obtaining and measuring pupil diameter. However, it remains undetermined determined whether these tools are suitable for use in occupational settings. This study explores the significance of pupil size variation as a biomarker for occupational risks and evaluates existing opensource methods for potential use in both research and occupational settings, with the goal of to prevent occupational accidents and improve the health and performance of workers. To this end, a two-phase systematic literature review was conducted in the Web of Science TM, ScienceDirect (R), and Scopus (R) databases. For the relevance of monitoring pupil size variation in occupational settings, 15 articles were included. The articles were divided into three groups: mental workload, occupational stress, and mental fatigue. In most cases, pupil dilation increased with workload enhancement and with higher levels of stress. Regarding fatigue, it was noted that an increase in this condition corresponded with a decrease in pupil size. With respect to the open-source methodologies, 16 articles were identified, which were categorized into two groups: algorithms and software. Convolutional neural networks (CNN) 1 have exhibited superior performance among the various algorithmic approaches studied. Building on this insight, and considering the evaluations of software options, MEYE emerges as the premier open-source system for deployment in occupational settings due to its compatibility with a standard computer webcam. This feature positions MEYE as a particularly practical tool for workers in stable environments, like those of developers and administrators.

2024

Plantar pressure thresholds as a strategy to prevent diabetic foot ulcers: A systematic review

Authors
Castro Martins, P; Marques, A; Coelho, L; Vaz, M; Costa, JT;

Publication
HELIYON

Abstract
Background: The development of ulcers in the plantar region of the diabetic foot originates mainly from sites subjected to high pressure. The monitoring of these events using maximum allowable pressure thresholds is a fundamental procedure in the prevention of ulceration and its recurrence. Objective: The aim of this review was to identify data in the literature that reveal an objective threshold of plantar pressure in the diabetic foot, where pressure is classified as promoting ulceration. The aim is not to determine the best and only pressure threshold for ulceration, but rather to clarify the threshold values most used in clinical practice and research, also considering the devices used and possible applications for offloading plantar pressure. Design: A systematic review. Methods: The search was performed in three electronic databases, by the PRISMA methodology, for studies that used a pressure threshold to minimize the risk of ulceration in the diabetic foot. The selected studies were subjected to eligibility criteria. Results: Twenty-six studies were included in this review. Seven thresholds were identified, five of which are intended for the inside of the shoe: a threshold of average peak pressure of 200 kPa; 25 % and 40-80 % reduction from initial baseline pressure; 32-35 mm Hg for a capillary perfusion pressure; and a matrix of thresholds based on patient risk, shoe size and foot region. Two other thresholds are intended for the barefoot, 450 and 750 kPa. The threshold of 200 kPa of pressure inside the shoe is the most agreed upon among the studies. Regarding the prevention of ulceration and its recurrence, the efficacy of the proposed threshold matrix and the threshold of reducing baseline pressure by 40-80 % has not yet been evaluated, and the evidence for the remaining thresholds still needs further studies. Conclusions: Some heterogeneity was found in the studies, especially regarding the measurement systems used, the number of regions of interest and the number of steps to be considered for the threshold. Even so, this review reveals the way forward to obtain a threshold indicative of an effective steppingstone in the prevention of diabetic foot ulcer.

2024

In-shoe plantar pressure measurement technologies for the diabetic foot: A systematic review

Authors
Castro Martins, P; Marques, A; Coelho, L; Vaz, M; Baptista, JS;

Publication
HELIYON

Abstract
Introduction: Loss of cutaneous protective sensation and high plantar pressures increase the risk for diabetic foot patients. Trauma and ulceration are imminent threats, making assessment and monitoring essential. This systematic review aims to identify systems and technologies for measuring in -shoe plantar pressures, focusing on the at -risk diabetic foot population. Methods: A systematic search was conducted across four electronic databases (Scopus, Web of Science, PubMed, Oxford Journals) using PRISMA methodology, covering articles published in English from 1979 to 2024. Only studies addressing systems or sensors exclusively measuring plantar pressures inside the shoe were included. Results: A total of 87 studies using commercially available devices and 45 articles proposing new systems or sensors were reviewed. The prevailing market offerings consist mainly of instrumented insoles. Emerging technologies under development often feature configurations with four, six or eight resistive sensors strategically placed within removable insoles. Despite some variability due to the inherent heterogeneity of human gait, these devices assess plantar pressure, although they present significant differences between them in measurement results. Individuals with diabetic foot conditions appears exhibit elevated plantar pressures, with reported peak pressures reaching approximately 1000 kPa. The results also showed significant differences between the diabetic and non -diabetic groups. Conclusion: Instrumented insoles, particularly those incorporating resistive sensor technology, dominate the field. Systems employing eight sensors at critical locations represent a pragmatic approach, although market options extend to systems with up to 960 sensors. Differences between devices can be a critical factor in measurement and highlights the importance of individualized patient assessment using consistent measurement devices.

2024

A New Equipment for Automatic Calibration of the Semmes-Weinstein Monofilament

Authors
Castro-Martins P.; Pinto-Coelho L.;

Publication
Lecture Notes in Mechanical Engineering

Abstract
Diabetic foot is a complication that carries a considerable risk in diabetic patients. The consequent loss of protective sensitivity in the lower limbs requires an early diagnosis due to the imminent possibility of ulceration or amputation of the affected limb. To assess the loss of protective sensitivity, the 10 gf Semmes-Weinstein (SW) monofilament is the most used first-line procedure. However, the used device is most often non-calibrated and its feedback can lead to decision errors. In this paper we present an equipment that is able to automatically conduct a metrological verification and evaluation of the 10 gf SW monofilament in the assessment of the loss of protective sensitivity. Additionally, the proposed equipment is able to simulate the practicioner’s procedure, or can be used for training purposes, providing force-feedback information. After calibration, displacement vs. buckling force contours were plotted for three distinct monofilaments, confirming then ability of the equipment to provide fast, detailed and precise information.

Supervised
thesis

2023

Controlo de Qualidade de Reveladores Radiográficos Procedimentos e Protocolos para uma Imagem Diagnóstica de Alta Qualidade

Author
JOEL DA SILVA SOUSA

Institution
IPP-ISEP

2023

Análise de Padrões de EEG em Ambientes de Trabalho Simulados com Realidade Virtual

Author
GONÇALO RIBEIRO DOS SANTOS

Institution
IPP-ISEP

2023

Criação de Bases de Dados de Imagens Histológicas Anotadas e Desenvolvimento de um Modelo de Classificação Automática de Patologias Mamárias

Author
CRISTINA ISABEL DA SILVA MOREIRA

Institution
IPP-ISEP

2023

Caracterização de personalidade através de padrões de EEG em processos de tomada de decisão - uma análise exploratória

Author
JOANA RAQUEL RODRIGUES PINTO

Institution
IPP-ISEP