Sensores de fibra ótica para arquiteturas e-Health

In this work, optical fiber sensors were developed and optimized for biomedical applications in wearable and non-intrusive and/or invisible solutions. As it was intended that the developed devices would not interfere with the user's movements and their daily life, the fibre optic sensors presented several advantages when compared to conventional electronic sensors, among others, the following stand out: size and reduced weight, biocompatibility, safety, immunity to electromagnetic interference and high sensitivity. In a first step, wearable devices with fibre optic sensors based in Fiber Bragg gratings (FBG) were developed to be incorporated into insoles to monitor different walking parameters based on the analysis of the pressure exerted on several areas of the insole. Still within this theme, other sensors were developed using the same sensing technology, but capable of monitoring pressure and shear forces simultaneously. This work was pioneering and allowed monitoring one of the main causes of foot ulceration in people with diabetes: shear. At a later stage, the study focused on the issue related with the appearance of ulcers in people with reduced mobility and wheelchair users. In order to contribute to the mitigation of this scourge, a system was developed composed of a network of fibre optic sensors capable of monitoring the pressure at various points of the wheelchair. It not only measures the pressure at each point, but also monitors the posture of the wheelchair user and advises him/her to change posture regularly to reduce the probability of this pathology occurring. Still within this application, another work was developed where the sensor not only monitored the pressure but also the temperature in each of the analysis points, thus indirectly measuring shear. In another phase, plastic fibre optic sensors were studied and developed to monitor the body posture of an office chair user. Simultaneously, software was developed capable of monitoring and showing the user all the acquired data in real time and warning for incorrect postures, as well as advising for work breaks. In a fourth phase, the study focused on the development of highly sensitive sensors embedded in materials printed by a 3D printer. The sensor was composed of an optical fibre with a FBG and the sensor body of a flexible polymeric material called "Flexible". This material was printed on a 3D printer and during its printing the optical fibre was incorporated. The sensor proved to be highly sensitive and was able to monitor respiratory and cardiac rate, both in wearable solutions (chest and wrist) and in "invisible" solutions (office chair).Neste trabalho foram desenvolvidos e otimizados sensores em fibra ótica para aplicações biomédicas em soluções vestíveis e não intrusivas/ou invisíveis. Tendo em conta que se pretende que os dispositivos desenvolvidos não interfiram com os movimentos e o dia-a-dia do utilizador, os sensores de fibra ótica apresentam inúmeras vantagens quando comparados com os sensores eletrónicos convencionais, de entre várias, destacam-se: tamanho e peso reduzido, biocompatibilidade, segurança, imunidade a interferências eletromagnéticas e elevada sensibilidade. Numa primeira etapa, foram desenvolvidos dispositivos vestíveis com sensores de fibra ótica baseados em redes de Bragg (FBG) para incorporar em palmilhas de modo a monitorizar diferentes parâmetros da marcha com base na análise da pressão exercida em várias zonas da palmilha. Ainda no âmbito deste tema, adicionalmente, foram desenvolvidos sensores utilizando a mesma tecnologia de sensoriamento, mas capazes de monitorizar simultaneamente pressão e forças de cisalhamento. Este trabalho foi pioneiro e permitiu monitorizar um dos principais responsáveis pela ulceração dos pés em pessoas com diabetes: o cisalhamento. Numa fase posterior, o estudo centrou-se na temática relacionada com o aparecimento de úlceras em pessoas com mobilidade reduzida e utilizadores de cadeiras de rodas. De modo a contribuir para a mitigação deste flagelo, procurou-se desenvolver um sistema composto por uma rede de sensores de fibra ótica capaz de monitorizar a pressão em vários pontos de uma cadeira de rodas e não só aferir a pressão em cada ponto, mas monitorizar a postura do cadeirante e aconselhá-lo a mudar de postura com regularidade, de modo a diminuir a probabilidade de ocorrência desta patologia. Ainda dentro desta aplicação, foi publicado um outro trabalho onde o sensor não só monitoriza a pressão como também a temperatura em cada um dos pontos de análise, conseguindo aferir assim indiretamente o cisalhamento. Numa outra fase, foi realizado o estudo e desenvolvimento de sensores de fibra ótica de plástico para monitorizar a postura corporal de um utilizador de uma cadeira de escritório. Simultaneamente, foi desenvolvido um software capaz de monitorizar e mostrar ao utilizador todos os dados adquiridos em tempo real e advertir o utilizador de posturas incorretas, bem como aconselhar para pausas no trabalho. Numa quarta fase, o estudo centrou-se no desenvolvimento de sensores altamente sensíveis embebidos em materiais impressos 3D. O sensor é composto por uma fibra ótica com uma FBG e o corpo do sensor por um material polimérico flexível, denominado “Flexible”. O sensor foi impresso numa impressora 3D e durante a sua impressão foi incorporada a fibra ótica. O sensor demonstrou ser altamente sensível e foi capaz de monitorizar frequência respiratória e cardíaca, tanto em soluções vestíveis (peito e pulso) como em soluções “invisíveis” (cadeira de escritório).Programa Doutoral em Engenharia Físic

Fiber Optic-Based Pressure Sensing Surface for Skin Health Management in Prosthetic and Rehabilitation Interventions

Applied physic

Assistive multi-sensor framework for prevention and monitoring of pressure ulcers

Pressure ulcers (PU) are injuries to the skin and soft tissues due to prolonged pressure and have a significant impact on the quality of a patient’s life. The common risk factors of PU are pressure, shearing forces, friction, moisture, temperature, and immobility. The use of low-tech and high-tech devices is effective in distributing the high pressure exerted on the patient’s body. However, patients can still develop PU because these devices do not provide any real-time information about the risk factors of PU development. With the help of sensors, smart beds are effective to monitor and prevent the development of PU but the prevalence of PU around the globe is still high due to the aging population. In this thesis, a multi-sensor framework is developed and tested to aid in the monitoring and prevention of PU. The proposed system is able to measure, process, and store real-time information about the numerous risk factors of PU. In addition, the framework does not need to be attached to the patient’s body in order to provide extra comfort. Different experiments are conducted to test the reliability and effectiveness of the proposed system. Experimental results indicate that the system is capable to provide the rate of repositioning, temperature, and pressure distribution

Smart Sensors for Healthcare and Medical Applications

This book focuses on new sensing technologies, measurement techniques, and their applications in medicine and healthcare. Specifically, the book briefly describes the potential of smart sensors in the aforementioned applications, collecting 24 articles selected and published in the Special Issue “Smart Sensors for Healthcare and Medical Applications”. We proposed this topic, being aware of the pivotal role that smart sensors can play in the improvement of healthcare services in both acute and chronic conditions as well as in prevention for a healthy life and active aging. The articles selected in this book cover a variety of topics related to the design, validation, and application of smart sensors to healthcare

Biomedical Engineering

Biomedical engineering is currently relatively wide scientific area which has been constantly bringing innovations with an objective to support and improve all areas of medicine such as therapy, diagnostics and rehabilitation. It holds a strong position also in natural and biological sciences. In the terms of application, biomedical engineering is present at almost all technical universities where some of them are targeted for the research and development in this area. The presented book brings chosen outputs and results of research and development tasks, often supported by important world or European framework programs or grant agencies. The knowledge and findings from the area of biomaterials, bioelectronics, bioinformatics, biomedical devices and tools or computer support in the processes of diagnostics and therapy are defined in a way that they bring both basic information to a reader and also specific outputs with a possible further use in research and development

Fiber bragg gratings for medical applications and future challenges: A review

In the last decades, fiber Bragg gratings (FBGs) have become increasingly attractive to medical applications due to their unique properties such as small size, biocompatibility, immunity to electromagnetic interferences, high sensitivity and multiplexing capability. FBGs have been employed in the development of surgical tools, assistive devices, wearables, and biosensors, showing great potentialities for medical uses. This paper reviews the FBG-based measuring systems, their principle of work, and their applications in medicine and healthcare. Particular attention is given to sensing solutions for biomechanics, minimally invasive surgery, physiological monitoring, and medical biosensing. Strengths, weaknesses, open challenges, and future trends are also discussed to highlight how FBGs can meet the demands of next-generation medical devices and healthcare system

Fiber Bragg Gratings for Medical Applications and Future Challenges: A Review

[EN] In the last decades, fiber Bragg gratings (FBGs) have become increasingly attractive to medical applications due to their unique properties such as small size, biocompatibility, immunity to electromagnetic interferences, high sensitivity and multiplexing capability. FBGs have been employed in the development of surgical tools, assistive devices, wearables, and biosensors, showing great potentialities for medical uses. This paper reviews the FBG-based measuring systems, their principle of work, and their applications in medicine and healthcare. Particular attention is given to sensing solutions for biomechanics, minimally invasive surgery, physiological monitoring, and medical biosensing. Strengths, weaknesses, open challenges, and future trends are also discussed to highlight how FBGs can meet the demands of next-generation medical devices and healthcare system.This work was supported in part by INAIL (the Italian National Institute for Insurance against Accident at Work), through the BRIC (Bando ricerche in collaborazione) 2018 SENSE-RISC (Sviluppo di abiti intelligENti Sensorizzati per prevenzione e mitigazione di Rischi per la SiCurezza dei lavoratori) Project under Grant ID10/2018, in part by the UCBM (Universita Campus Bio-Medico di Roma) under the University Strategic HOPE (HOspital to the PatiEnt) Project, in part by the EU Framework Program H2020-FETPROACT-2018-01 NeuHeart Project under Grant GA 824071, by FCT/MEC (Fundacao para a Ciencia e Tecnologia) under the Projects UIDB/50008/2020 - UIDP/50008/2020, and by REACT (Development of optical fiber solutions for Rehabilitation and e-Health applications) FCT-IT-LA scientific action.Lo Presti, D.; Massaroni, C.; Leitao, CSJ.; Domingues, MDF.; Sypabekova, M.; Barrera, D.; Floris, I.... (2020). Fiber Bragg Gratings for Medical Applications and Future Challenges: A Review. IEEE Access. 8:156863-156888. https://doi.org/10.1109/ACCESS.2020.3019138S156863156888

Smart Textiles Production

The research field of smart textiles is currently witnessing a rapidly growing number of applications integrating intelligent functions in textile substrates. With an increasing amount of new developed product prototypes, the number of materials used and that of specially designed production technologies are also growing. This book is intended to provide an overview of materials, production technologies, and product concepts to different groups concerned with smart textiles. It will help designers to understand the possibilities of smart textile production, so that they are enabled to design this type of products. It will also help textile and electronics manufacturers to understand which production technologies are suitable to meet certain product requirements

Desenvolvimento e otimização de sensores em fibra ótica produzidos por laser de femtosegundo

In this work, optical fibre sensors were developed and optimized using a pulsed femtosecond laser. In addition to the inherent advantages of using femtosecond pulses, by emitting radiation in the NIR band, it was possible to modify the refractive index inside dielectric materials, namely silica and polymer optical fibres. Prior to the manufacturing of optical structures, a theoretical study was carried out on the peculiarities of writing-systems based on femtosecond lasers, as well as on the most common devices inscribed in optical fibres, namely Bragg gratings, long period gratings, and Fabry-Pérot interferometers. After assembling femtosecond NIR laser system, Bragg gratings, long period gratings, Fabry-Pérot interferometers, and interferometers based on the optical Vernier effect were manufactured using the direct-writing and phase mask methods. Using the micromachining setup, different structures were created in already existing optical fibre sensors, namely channels in hollow Fabry-Pérot cavities and laser etching around Bragg gratings inscribed in polymers optical fibres. The spectral responses of all devices were extensively characterized to, mainly, variations of temperature and strain, revealing unique sensitivity values, especially for the interferometers based on the optical Vernier effect (> 1 nm/°C and 0.1 nm/µε for temperature and strain, respectively). To demystify the thermal stability of fibre Bragg gratings, a theoretical and experimental study was carried out where several Bragg gratings were inscribed by different techniques, involving different lasers as well as silica and polymer optical fibres. The experimental results corroborated the theoretical predictions, where it was concluded that the gratings inscribed by the point-to-point method using a femtosecond laser have a greater thermal stability and lifetime, even when subjected to longer and higher temperature regimes. Finally, a bridge was stablished between the fundamental research developed during the manufacture of the elementary optical fibre sensors, and possible applications. Five different sensor concepts were demonstrated and tested, capable of detecting variations in magnetic fields, fluids refractive index, temperature, strain and humidity. As results, astonishing sensitivity values were attained, and several cross-sensitivity problems were mitigated, thus establishing the foundations for the development of new prototypes for the future.Neste trabalho foram desenvolvidos e otimizados sensores em fibra ótica através de um laser pulsado de femtosegundo. Para além das vantagens inerentes de usar pulsos da ordem do femtosegundo, ao emitir radiação na banda do infravermelho foi possível modificar o índice de refração no interior de materiais dielétricos, nomeadamente fibras óticas de sílica e polímero. Antes de proceder ao fabrico das estruturas óticas, foi realizado um estudo teórico sobre as peculiaridades dos sistemas de escrita baseados em lasers de femtosegundo, bem como sobre os principais dispositivos inscritos em fibra ótica, nomeadamente redes de Bragg, redes de período longo, e interferómetros de Fabry-Pérot. Após montado o sistema laser NIR de femtosegundo, através de inscrição direta e por máscara de fase foram fabricadas redes de Bragg, redes de período longo, interferómetros de Fabry-Pérot, e interferómetros baseados no efeito ótico de Vernier. Com a montagem de micromaquinação, diferentes estruturas foram criadas em sensores já existentes, nomeadamente buracos em cavidades Fabry-Pérot e remoção de material ao redor de redes de Bragg. As respostas espetrais de todos os dispositivos foram extensivamente caracterizadas, nomeadamente a variações de temperatura e tensão, revelando elevados valores de sensibilidades, especialmente para os interferómetros baseados no efeito ótico de Vernier (> 1 nm/°C e 0.1 nm/µε para temeprature e tensão, respetivamente). Para desmistificar a estabilidade térmica de redes de Bragg em fibra ótica, foi feito um estudo teórico e experimental onde várias redes de Bragg foram gravadas por diferentes técnicas, envolvendo diferentes lasers e fibras óticas de sílica e polímero. Os resultados experimentais corroboraram as previsões teóricas, onde se concluiu que as redes gravadas pelo método de ponto-a-ponto usando um laser de femtosegundo detêm uma maior estabilidade térmica e tempo de vida, mesmo quando submetidas a regimes longos de altas temperaturas. Por fim, foi feita a ponte entre a investigação fundamental desenvolvida durante o fabrico de dispositivos elementares em fibras óticas e possíveis aplicações. Foram demonstrados e testados cinco conceitos diferentes de sensores, capazes de detetar variações de campos magnéticos, índice de refração de fluídos, temperatura, tensão e humidade. Foram atingidos valores de sensibilidade surpreendentes, bem como mitigados problemas de sensibilidade cruzada, tendo sido assim estabelecidas as fundações para o desenvolvimento de novos protótipos para o futuro.Programa Doutoral em Engenharia Físic