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A Novel Access Technology Based on Infrared Thermography for People with Severe Motor ImpairmentsMemarian, Negar 18 February 2011 (has links)
Many individuals with severe motor impairments are cognitively capable, but because of their physical impairments, unable to express their intention through conventional means of communication. Access technologies are devices that attempt to translate the intention of these individuals into functional activity by harnessing their residual physical or physiological abilities. The primary objective of this thesis was to design and develop a novel non-invasive and non-contact access technology based on infrared thermal imaging. This access technology translates the local temperature change associated with voluntary mouth opening to activation of a binary switch such as a mouse click or key press. To this end, an algorithm based on motion and temperature analyses, and morphological and anthropometric filters was designed to detect mouth opening activity in thermal video in real-time. The secondary objective of this thesis was to introduce a mutual information measure for objective assessment of binary switch users’ performance. A model was suggested, in which combination of cognitive and physical abilities of the human user of a binary access switch constitute a communication channel. The proposed mutual information measure estimates the rate of information transmission in the ‘human communication channel’ during stimulus response tasks. Using this measure, in a study with ten able-bodied participants, the infrared thermal switch was validated against a conventional chin switch. Impairments in body functions and structures that may contraindicate the use of the infrared thermal switch were explored in a study with seven clients, with severe disabilities. Potential hard and soft technological solutions to mitigate the effect of these impairments on infrared thermal switch use were recommended. Finally the infrared thermal switch was tailored to meet the needs of a young man with severe spastic quadriplegic cerebral palsy, who had no other means of physical access.
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[pt] TRANSFERÊNCIA ULTRASSÔNICA DE ENERGIA E DADOS ATRAVÉS DE CAMADAS DE METAL E FLUIDO UTILIZANDO MODULAÇÃO EM FREQUÊNCIA / [en] ULTRASONIC ENERGY AND DATA TRANSFER THROUGH METAL AND FLUID LAYERS USING FREQUENCY MODULATIONRAPHAEL BOTELHO PEREIRA 18 July 2023 (has links)
[pt] A necessidade de transmitir energia e dados através de barreiras metálicas tem sido cada vez maior em aplicações industriais, onde não é possível a penetração de cabos elétricos, ou o uso de ondas eletromagnéticas, tais como, por exemplo, em sistemas de sensoriamento de cimentação em poços de petróleo. Ondas acústicas podem ser uma solução para esse problema, porque não são afetadas pelo efeito gaiola de Faraday, além de possuírem baixa atenuação ao atravessarem metais. Diversos esforços foram feitos para realizar a transmissão de dados através de camadas metálicas, com abordagens que variam em composição do canal acústico, taxa de transmissão, transmissão simultânea de dados e energia e complexidade dos circuitos empregados; existe, porém, carência de trabalhos que envolvam camadas metal-fluído-metal. Este trabalho apresenta uma possível solução utilizando ondas acústicas como meio de transportar energia e dados em um canal composto de barreiras com duas camadas metálicas e uma de fluído. Aqui propõe-se uma inovadora técnica de controle automático de ganho e um melhor aproveitamento da largura de banda do canal acústico, que permite maior taxa de transmissão de dados. É ainda proposta uma técnica para controle dinâmico da portadora enviada ao lado passivo do sistema. Inicialmente, foi feita uma análise de um modelo numérico, baseado em trabalhos anteriores, fundamentado na propagação de ondas acústicas e baseado na analogia acustoelétrica. Em seguida, desenvolveu-se um sistema eletrônico para receber / transmitir energia e dados digitais, modulados em frequência, de um lado ao outro do sistema. Por fim, análises experimentais foram feitas utilizando como canal acústico, um conjunto de duas placas planas de aço (de 5 mm) separadas por uma camada de fluído (de 100 mm) e dois transdutores alinhados axialmente, realizando a transferência de energia e dados digitais modulados em frequência. O sistema foi capaz de realizar a transferência de dados a uma taxa de 19200 bps e simultaneamente uma transferência de energia de 66 mW, com essa energia foi possível alimentar o modulo eletrônico e um sensor de pressão e temperatura. Durante os testes foi constatado um aproveitamento de 5,5 por cento da energia aplicada ao canal, e foi possível atingir uma taxa de erro de bit de 5 por cento em um teste com 2 h e 30 min de duração, utilizando o canal acústico com camadas de múltiplos materiais propostos. O sistema de controle de portadora funcionou adequadamente, permitindo uma redução de consumo de até 53 por cento. O controle automático de ganho permitiu uma redução de 50 por cento na taxa de erro de decodificação. Demonstra-se, então, a viabilidade de tais sistemas de controle propostos, os quais podem ser úteis em casos onde existam variações nas características acústicas do canal em questão que, em conjunto com a transferência não intrusiva, pode prover solução para sistemas de sensoriamento. / [en] The need for energy and data transmission through metallic barriers is increasing in industrial applications, where the penetration of electrical waves or the use of electrical waves is not possible. An example of such a scenario is the monitoring of cementing in wellbore applications. Acoustic waves are promising to solve this problem, since they are not affected by the Faraday cage effect, in addition, they present low attenuation when propagating in metals. Several efforts have been made to carry out data transmission through metallic layers, with approaches that vary in composition of the acoustic channel, transmission speed, simultaneous transmission of data and energy and the complexity of the circuits used, but there is a lack of works involving metal-fluid-metal layers. This work presents a possible solution using acoustic waves as a mean of transporting energy and data in a channel composed of barriers with two metallic layers and one fluid layer. Here, it is proposed a novel technique for automatic gain control and better use of the available bandwidth of the acoustic channel, which allows higher data transmission speed. Also, a technique for dynamic control of the carrier sent to the passive side of the system is proposed. Initially, an analysis with a numerical model was made, following previous works, which is based on the propagation of acoustic waves and relying on the acoustoelectric analogy. Then, an electronic system was developed to receive/transmit power and digital data, frequency modulated, from one side of the system to the other. Finally, experimental analyzes were performed using as an acoustic channel, a set of two flat steel plates (5 mm) separated by a fluid layer (100 mm) and a pairs of axially aligned transducers, performing the energy transfer and frequency modulated digital data. The system was able to transfer data at a rate of 19200 bps and simultaneously a transfer of energy of 66 mW, with this energy it was possible to feed the inside block module and a pressure and temperature sensor. During the tests, it was verified that 5.5 per cent of the energy applied to the channel was used, and it a bit error rate down to of 5 per cent was reached in a test with 2 h and 30 min of duration, using the multi-layered acoustic. The automatic carrier control system worked as expected and allowed one to reduce energy consumption in 53 per cent. The automatic gain control allowed one to reduce the error rate in 50 per cent. These control systems prove the feasibility of the proposed system and further show the usefulness of the system in scenarios that are subject to variations in the acoustic characteristics of the channel.
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Advanced Electro-Quasistatic Human Body Communication and Powering: From Theory to Application for Internet of BodiesArunashish Datta (19207768) 07 August 2024 (has links)
<p dir="ltr">Decades of semiconductor technology scaling and breakthroughs in communication technology have miniaturized computing, embedding it everywhere, enabling the development of smart things connected to the internet, forming the Internet of Things. Further miniaturization of devices has led to an exponential increase in the number of devices in and around the body in the last decade, forming a subset of IoT which is increasingly becoming popular as the Internet of Bodies (IoB). The gradual shift from the current form of human-electronics coexistence to human-electronics cooperation, is the vision of Internet of Bodies (IoB). This vision of a connected future with devices in and around our body talking to each other to assist their day-to-day functions demands energy efficient means of communication. Electro-Quasistatic Human Body Communication (EQS-HBC) has been proposed as an exciting alternative to traditional Radio Frequency based methodologies for communicating data around the body. In this dissertation, we expand the boundaries of wearable and implantable IoB nodes using Electro-Quasistatic Human Body Communication and Powering by developing advanced channel models and demonstrating novel applications.</p><p dir="ltr">Leveraging the advanced channel models developed for wearable EQS-HBC, we demonstrate wearable applications like ToSCom which extend the use cases of touchscreens to beyond touch detection and location to enable high-speed communication strictly through touch. We further demonstrate an application of EQS Resonant Human Body Powering to demonstrate Step-to-Charge, allowing mW-scale wireless power transfer to wearable devices. With increasing connected implanted healthcare devices becoming a part of the IoB space, we benchmark RF-based technologies for In-Body to Out-of-Body (IBOB) communication using novel in-vivo experiments. We then explore EQS-HBC in the realm of IBOB communication using advanced channel modeling, revealing its potential for low-power and physically secure data transfer from implantable devices to wearable nodes on the body, demonstrating its potential in extending the battery life span of implantable nodes. Finally, an overview of the potential of IoB devices is analyzed with the use of EQS-HBC where we propose a human-inspired distributed network of IoB nodes which brings us a step closer to the potential for perpetually operable devices in and around the body.</p>
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