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Authors
Abstract(s)
O funcionamento do sistema sensorial humano é baseado num conjunto de biossensores
localizados na nossa pele que permitem detetar estímulos como temperatura, pressão,
rugosidade, etc. Este sistema de recolha de informação, através de mecanorreceptores,
termorreceptores, entre outros, usa como meio de transmissão nervos e tratos sensitivos
que, em conjunto com os recetores, formam o nosso sistema somatossensorial.
Ao existir a perda ou amputação de um membro, um dos problemas encontrados a longo
prazo, para lá da obvia falta do membro, será a síndrome do membro fantasma, que
resulta de um funcionamento anormal do sistema nervoso para tentar compensar a
perda do membro. Uma das soluções base para substituir as funcionalidades perdidas ao
nível físico é o uso de uma prótese. Neste assunto, existem várias dificuldades,
nomeadamente ao nível adaptativo da prótese com corpo e vice-versa, mas também
devido às limitações ainda existentes a nível funcional das próteses atualmente
disponíveis. Neste sentido torna-se crucial aperfeiçoar as próteses não só ao nível do seu
funcionamento como também na possibilidade de lhes conferir propriedades mais
semelhantes ao membro original, sendo neste caso, a sensibilidade uma propriedade.
No âmbito desta dissertação, os objetivos principais são a fabricação da prótese, e da luva
sensorial e as suas instrumentações, conferindo a uma prótese de mão a possibilidade de
detetar informação associada à sensibilidade ao toque e que a mesma a consiga
transmitir ao utilizador de uma forma o mais semelhante possível ao membro original.
Para tal, acoplou-se à superfície da prótese um sistema composto por sensores
piezoresistivos ligados a um processador (Arduino), que no seu conjunto, irão replicar os
biossensores e nervos do antebraço.
Obteve-se um sistema que permite ao utilizador alguma sensibilidade, ou seja,
transformar o input recebido num output o qual consiga ser detetado e traduzido pelo
sistema nervoso.
The reproduction of the human nervous system has been a focus of study´s for many years. It allowed scientist to gain knowledge on how we fell touch, heat, cold, pain and how we perceived the world around us and how we act towards those inputs. The first layer of contact with the world is our skin, which is composed by a multilayered sensor system that is differentiated, not only between its layers but also between different types of biosensors. Each sensor has specifically input read and range that overall forms a very complex network that acts as an interface on how we perceive, interpret, and react towards our surroundings and how we take action depending on the inputs received. The conceptualization of an artificial sensory system, mimicking the human system, is a complex design with multiple sensors working simultaneous as it receives inputs from multiple sources and gives the user the same inputs as it normally receives. To simplify the overall complexity of the system, the focus was put on the reproduction of the sensation of touch, using a 3D prosthetics of a forearm and hand to emulate a human one. The design of the prosthetic was individualized in sections, hand and forearm. The forearm bearded the overall control system and hardware for the movement of the hand, separating the indicator, middle, ring, and pinky fingers movement from the thumb, in which its movement is wider by the type of design used allowing a wider grab. This way, not only the anatomy is precise, but also gives the prosthetic a wider range in movement and action. Its production was carefully done using 3D printing. By optimizing each parameter like printing time, quality, infill percentage, ironing and type of material used we produced a quality model with the capacity to achieve a high-performance hand movement with the capacity to easily add-on systems like a sensory hand glove. The sensitive mimicking add-on system developed, focused on the ability to sense touch as a primary target. Using the piezoresistive effect, as the base to transform the inputs received to signals, that can be translated and send to the nervous system, there was an implementation of piezoresistive sensors in the palm surface of a glove. A total of 16 sensors were implemented and wired simultaneously to an Arduino Mega2560 and the performance was better than expected, allowing not only the measure of force, voltage, capacitance, and analog read of each sensor uses, but also the location of that same force.
The reproduction of the human nervous system has been a focus of study´s for many years. It allowed scientist to gain knowledge on how we fell touch, heat, cold, pain and how we perceived the world around us and how we act towards those inputs. The first layer of contact with the world is our skin, which is composed by a multilayered sensor system that is differentiated, not only between its layers but also between different types of biosensors. Each sensor has specifically input read and range that overall forms a very complex network that acts as an interface on how we perceive, interpret, and react towards our surroundings and how we take action depending on the inputs received. The conceptualization of an artificial sensory system, mimicking the human system, is a complex design with multiple sensors working simultaneous as it receives inputs from multiple sources and gives the user the same inputs as it normally receives. To simplify the overall complexity of the system, the focus was put on the reproduction of the sensation of touch, using a 3D prosthetics of a forearm and hand to emulate a human one. The design of the prosthetic was individualized in sections, hand and forearm. The forearm bearded the overall control system and hardware for the movement of the hand, separating the indicator, middle, ring, and pinky fingers movement from the thumb, in which its movement is wider by the type of design used allowing a wider grab. This way, not only the anatomy is precise, but also gives the prosthetic a wider range in movement and action. Its production was carefully done using 3D printing. By optimizing each parameter like printing time, quality, infill percentage, ironing and type of material used we produced a quality model with the capacity to achieve a high-performance hand movement with the capacity to easily add-on systems like a sensory hand glove. The sensitive mimicking add-on system developed, focused on the ability to sense touch as a primary target. Using the piezoresistive effect, as the base to transform the inputs received to signals, that can be translated and send to the nervous system, there was an implementation of piezoresistive sensors in the palm surface of a glove. A total of 16 sensors were implemented and wired simultaneously to an Arduino Mega2560 and the performance was better than expected, allowing not only the measure of force, voltage, capacitance, and analog read of each sensor uses, but also the location of that same force.
Description
Keywords
Impressão 3d Próteses Sensores Piezoelétricos Sistema Nervoso Sistema Sensorial