Gesture recognition is becoming increasingly popular as an input mechanism for human-computer interfaces. The availability of MEMS (Micro-Electromechanical System) 3-axis linear accelerometers allows for the design of an inexpensive mobile gesture recognition system. Wearable inertial sensors are a low-cost, low-power solution to recognize gestures and, more generally, track the movements of a person. Gesture recognition algorithms have traditionally only been implemented in cases where ample system resources are available, i.e. on desktop computers with fast processors and large amounts of memory. In the cases where a gesture recognition algorithm has been implemented on a resource-constrained device, only the simplest algorithms were implemented to recognize only a small set of gestures. Current gesture recognition technology can be improved by making algorithms faster, more robust, and more accurate. The most dramatic results in optimization are obtained by completely changing an algorithm to decrease the number of computations. Algorithms can also be optimized by profiling or timing the different sections of the algorithm to identify problem areas. Gestures have two aspects of signal characteristics that make them difficult to recognize: segmentation ambiguity and spatio-temporal variability. Segmentation ambiguity refers to not knowing the gesture boundaries, and therefore reference patterns have to be matched with all possible segments of input signals. Spatio-temporal variability refers to the fact that each repetition of the same gesture varies dynamically in shape and duration, even for the same gesturer. The objective of this study was to evaluate the various gesture recognition algorithms currently in use, after which the most suitable algorithm was optimized in order to implement it on a mobile device. Gesture recognition techniques studied include hidden Markov models, artificial neural networks and dynamic time warping. A dataset for evaluating the gesture recognition algorithms was gathered using a mobile device’s embedded accelerometer. The algorithms were evaluated based on computational efficiency, recognition accuracy and storage efficiency. The optimized algorithm was implemented in a user application on the mobile device to test the empirical validity of the study. / Dissertation (MEng)--University of Pretoria, 2009. / Electrical, Electronic and Computer Engineering / unrestricted

We propose the concept of spatial analytic interfaces (SAIs) as a tool for performing in-situ, everyday analytic tasks. Mobile computing is now ubiquitous and provides access to information at nearly any time or place. However, current mobile interfaces do not easily enable the type of sophisticated analytic tasks that are now well-supported by desktop computers. Conversely, desktop computers, with large available screen space to view multiple data visualizations, are not always available at the ideal time and place for a particular task. Spatial user interfaces, leveraging state-of-the-art miniature and wearable technologies, can potentially provide intuitive computer interfaces to deal with the complexity needed to support everyday analytic tasks. These interfaces can be implemented with versatile form factors that provide mobility for doing such taskwork in-situ, that is, at the ideal time and place. We explore the design of spatial analytic interfaces for in-situ analytic tasks, that leverage the benefits of an upcoming generation of light-weight, see-through, head-worn displays. We propose how such a platform can meet the five primary design requirements for personal visual analytics: mobility, integration, interpretation, multiple views and interactivity. We begin with a design framework for spatial analytic interfaces based on a survey of existing designs of spatial user interfaces. We then explore how to best meet these requirements through a series of design concepts, user studies and prototype implementations. Our result is a holistic exploration of the spatial analytic concept on a head-worn display platform. / October 2016

<p>This thesis presents a set of concepts and a general design approach for designing Mixed Reality environments based on the idea that the physical (real) world and the virtual (digital) world are equally important and share many properties. Focus is on the design of a technology infrastructure intended to relieve people from some of the extra efforts currently needed when performing activities that make heavy use of both worlds. An important part of the proposed infrastructure is the idea of creating Physical-Virtual Artefacts, objects manifested in the physical and the virtual world at the same time.</p><p>The presented work challenges the common view of Human-Computer Interaction as a research discipline mainly dealing with the design of “user interfaces” by proposing an alternative or complementary view, a physical-virtual design perspective, abstracting away the user interface, leaving only physical and virtual objects. There are at least three motives for adopting such a design perspective: 1) people well acquainted with specific (physical and virtual) environments are typically more concerned with the manipulation of (physical and virtual) objects than the user interface through which they are accessed. 2) Such a design stance facilitates the conceptualisation of objects that bridge the gap between the physical and the virtual world. 3) Many physical and virtual objects are manifested in both worlds already today. The existing conceptual link between these physical and virtual objects has only to be complemented with causal relations in order to reduce the costs in crossing the border between the physical and the virtual world.</p><p>A range of concepts are defined and discussed at length in order to frame the design space, including<i> physical-virtual environment gap, physical-virtual activity, physical-virtual artefact, </i>and<i> physical-virtual environment</i>.</p><p>Two conceptual models of physical-virtual space are presented as a result of adopting the physical-virtual design perspective: for the analysis of object logistics in the context of physical-virtual activities, and for describing structural properties of physical-virtual space respectively. A prototype system offering some degree of physical-virtual infrastructure is also presented.</p>

This thesis presents a set of concepts and a general design approach for designing Mixed Reality environments based on the idea that the physical (real) world and the virtual (digital) world are equally important and share many properties. Focus is on the design of a technology infrastructure intended to relieve people from some of the extra efforts currently needed when performing activities that make heavy use of both worlds. An important part of the proposed infrastructure is the idea of creating Physical-Virtual Artefacts, objects manifested in the physical and the virtual world at the same time. The presented work challenges the common view of Human-Computer Interaction as a research discipline mainly dealing with the design of “user interfaces” by proposing an alternative or complementary view, a physical-virtual design perspective, abstracting away the user interface, leaving only physical and virtual objects. There are at least three motives for adopting such a design perspective: 1) people well acquainted with specific (physical and virtual) environments are typically more concerned with the manipulation of (physical and virtual) objects than the user interface through which they are accessed. 2) Such a design stance facilitates the conceptualisation of objects that bridge the gap between the physical and the virtual world. 3) Many physical and virtual objects are manifested in both worlds already today. The existing conceptual link between these physical and virtual objects has only to be complemented with causal relations in order to reduce the costs in crossing the border between the physical and the virtual world. A range of concepts are defined and discussed at length in order to frame the design space, including physical-virtual environment gap, physical-virtual activity, physical-virtual artefact, and physical-virtual environment. Two conceptual models of physical-virtual space are presented as a result of adopting the physical-virtual design perspective: for the analysis of object logistics in the context of physical-virtual activities, and for describing structural properties of physical-virtual space respectively. A prototype system offering some degree of physical-virtual infrastructure is also presented.

How can vibrotactile stimuli be used to create a technology-mediated somatic learning experience? This question motivates this practice-based research, which explores how the Feldenkrais Method and cognate neuroscience research can be applied to technology design. Supported by somaesthetic philosophy, soma-based design theories, and a critical acknowledgement of the socially-inflected body, the research develops a systematic method grounded in first- and third-person accounts of embodied experience to inform the creation and evaluation of design of Haplós, a wearable, user-customisable, remote-controlled technology that plays methodically composed vibrotactile patterns on the skin in order to facilitate body awareness—the major outcome of this research and a significant contribution to soma-based creative work. The research also contributes to design theory and somatic practice by developing the notion of a somatic learning affordance, which emerged during course of the research and which describes the capacity of a material object to facilitate somatic learning. Two interdisciplinary collaborations involving Haplós contribute to additional fields and disciplines. In partnership with experimental psychologists, Haplós was used in a randomised controlled study that contributes to cognitive psychology by showing that vibrotactile compositions can reduce, with statistical significance, intrusive food-related thoughts. Haplós was also used in Bisensorial, an award-winning, collaboratively developed proof-of-concept of a neuroadaptive vibroacoustic therapeutic device that uses music and vibrotactile stimuli to induce desired mental states. Finally, this research contributes to cognitive science and embodied philosophy by advancing a neuroscientific understanding of vibrotactile somaesthetics, a novel extension of somaesthetic philosophy.

Die industrielle Instandhaltung ist ein erheblicher Kostenfaktor während der Betriebsphase einer verfahrenstechnischen Produktionsanlage. Insbesondere der Mangel an technischen Möglichkeiten zum Informationsaustausch des Instandhaltungspersonals mit der digitalen Anlage während der Arbeiten im Feld erzeugt hohe Kosten. Durch die entstehenden Medienbrüche sinkt die Qualität der Informationen in der Digitalen Anlage erheblich. Mobile Informationssysteme können diese Medienbrüche beseitigen und die Informationsqualität in der Digitalen Anlage entscheidend verbessern. Das Konzept der Distributed Wearable User Interfaces (DWUI) stellt einen integrierten Ansatz zur flexiblen Zusammenstellung gebrauchstauglicher Benutzungsschnittstellen für komplexe Arbeitsabläufe in widrigen Arbeitssituationen bereit. Diese setzen sich aus Interaktionsgeräten zusammen, die in einem kabellosen körpernahen Funknetzwerk miteinander verbunden sind und in ihrer Kombination die Benutzungsschnittstelle zu einem mobilen System bilden. Die Geräte sind ergonomisch und funktional optimal am Körper des Nutzers verteilt, wobei jedes Gerät eigenständig nutzbar und für eine bestimmte Aufgabe oder einen bestimmten Nutzungskontext optimiert ist. Die Ein- und Ausgaberäume der Geräte werden in einem integrierten Interaktionsraum harmonisiert. Im Rahmen dieser Arbeit wird zunächst der Nutzungskontext der mobilen IT-gestützten Instandhaltung verfahrenstechnischer Produktionsanlagen im Hinblick auf Nutzungsszenarien und Anwendungsfälle für mobile Informationssysteme festgelegt. Darauf aufbauend werden Anforderungen an derartige Systeme spezifiziert und Gestaltungsgrundlagen und Empfehlungen speziell für DWUI-basierte mobile Informationssysteme erarbeitet. Anschließend wird eine Reihe spezieller Interaktionsgeräte vorgestellt, die verschiedene Interaktionsprinzipien, Techniken und Modalitäten umsetzen. Um diese Geräte in einem kollaborativen DWUI organisieren zu können, wird ein spezielles Kommunikationsprotokoll entworfen und prototypisch umgesetzt. Eine mobile Anwendung zur Instandhaltungsunterstützung wird vorgestellt, welche das DWUI-Kommunikationsprotokoll unterstützt und mit verschiedenen DWUI-Konfigurationen vollständig bedienbar ist. Diese Anwendung wird integriert in ein komplexes Unternehmensnetzwerk, über das sie Zugriff auf industrietypische computergestützte Planungswerkzeuge erhält. Anhand des resultierenden Gesamtsystems werden die prinzipielle Tauglichkeit und die Vorteile des DWUI-Konzepts demonstriert.

[pt] Dores no pé e joelho estão relacionadas com patologias ortopédicas e lesões nos membros inferiores. Desde a corrida de rua até o treinamento funcional CrossFit, estas dores e lesões estão correlacionadas com a distribuição iregular da pressão plantar e o posicionamento inadequado do joelho durante a prática física de longo prazo, e podem levar a lesões ortopédicas graves se o padrão de movimento não for corrigido. Portanto, o monitoramento da distribuição da pressão plantar do pé e das características espaciais e temporais das irregularidades no posicionamento dos pés e joelhos são de extrema importância para a prevenção de lesões. Este trabalho propõe uma plataforma, composta de uma rede de sensores vestíveis e um classificador de Reconhecimento de Atividade Humana (HAR), para fornecer feedback em tempo real de exercícios funcionais, visando auxiliar educadores físicos a reduzir a probabilidade de lesões durante o treinamento. Realizamos um experimento com 12 voluntários diversos para construir um classificador HAR com aproximadamente de 87 porcento de precisão geral na classificação, e um segundo experimento para validar nosso modelo de avaliação física. Por fim, realizamos uma entrevista semi estruturada para avaliar questões de usabilidade e experiência do usuário da plataforma proposta.Visando uma pesquisa replicável, fornecemos informações completas sobre o hardware e o código fonte do sistema, e disponibilizamos o conjunto de dados do experimento. / [en] Foot and knee pain fave been associated with numerous orthopedic pathologies and injuries of the lower limbs. From street running to CrossFitTM functional training, these common pains and injuries correlate highly with unevenly distributed plantar pressure and knee positioning during long-term physical practice and can lead to severe orthopedic injuries if the movement pattern is not amended. Therefore, the monitoring of foot plantar pressure distribution and the spatial and temporal characteristics of foot and knee positioning abnomalities is of utmost importance for injury prevention. This work proposes a platform, composed af an lot wearable body sensor network and a Human Activity Recognition (HAR), to provide realtime feedback of functional exercises, aiming to enhace physical educators capability to mitigate the probability of injuries during training. We conducted an experiment with 12 diverse volunteers to build a HAR classifier that achieved about 87 percent overall classification accuracy, and a second experiment to validate our physical evaluation model. Finally, we performed a semi-structured interview to evaluate usability and user experience issues regarding the proposed platform. Aiming at a replicable research, we provide full hardware information, system source code and a public domain dataset.

Recent years have seen an influx of medical technologies capable of remotely monitoring the health and behaviours of individuals to detect, manage and prevent health problems. Known collectively as personal health monitoring (PHM), these systems are intended to supplement medical care with health monitoring outside traditional care environments such as hospitals, ranging in complexity from mobile devices to complex networks of sensors measuring physiological parameters and behaviours. This research project assesses the potential ethical implications of PHM as an emerging medical technology, amenable to anticipatory action intended to prevent or mitigate problematic ethical issues in the future. PHM fundamentally changes how medical care can be delivered: patients can be monitored and consulted at a distance, eliminating opportunities for face-to-face actions and potentially undermining the importance of social, emotional and psychological aspects of medical care. The norms evident in this movement may clash with existing standards of 'good' medical practice from the perspective of patients, clinicians and institutions. By relating utilitarianism, virtue ethics and theories of surveillance to Habermas' concept of colonisation of the lifeworld, a conceptual framework is created which can explain how PHM may be allowed to change medicine as a practice in an ethically problematic way. The framework relates the inhibition of virtuous behaviour among practitioners of medicine, understood as a moral practice, to the movement in medicine towards remote monitoring. To assess the explanatory power of the conceptual framework and expand its borders, a qualitative interview empirical study with potential users of PHM in England is carried out. Recognising that the inherent uncertainty of the future undermines the validity of empirical research, a novel epistemological framework based in Habermas' discourse ethics is created to justify the empirical study. By developing Habermas' concept of translation into a procedure for assessing the credibility of uncertain normative claims about the future, a novel methodology for empirical ethical assessment of emerging technologies is created and tested. Various methods of analysis are employed, including review of academic discourses, empirical and theoretical analyses of the moral potential of PHM. Recommendations are made concerning ethical issues in the deployment and design of PHM systems, analysis and application of PHM data, and the shortcomings of existing research and protection mechanisms in responding to potential ethical implications of the technology.