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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Effects of display position on guided repair and maintenance assisted by head-mounted display (HMD)

Yang, Tao 08 June 2015 (has links)
Over the last few years, there have been striking developments in wearable computing. Among all the different forms of wearable devices, Head Mounted Displays (HMDs) are deemed the first seamless solution to enabling workers with real time contextual information and allowing companies to integrate with existing back-end systems. The hands-free feature that come along with the HMDs is also believed a great advantage over many traditional technologies. However, few studies had discussed the impact of different design characteristics of head mounted displays on task performance. This study aimed to find out how different display positions of Head Mounted Displays may affect the performance of workers performing guided repair and maintenance tasks. A set of car maintenance tasks were performed by 20 participants with task guidance presented at four Display Conditions: above-eye HMD, eye-centered HMD, below-eye HMD and the traditional paper manual. Time and errors were measured and discussed, as well as other user experience related measurements.
92

Don’t Touch: Social Appropriateness of Touch Sensor Placement on Interactive Lumalive E-Textile Shirts

Cheng, Sylvia Hou-Yan 31 August 2011 (has links)
We discuss the design of an e-textile shirt with an interactive Lumalive display featuring a touch-controlled image browser. To determine where to place touch sensors, we investigated which areas of the Lumalive shirt users would be comfortable touching or being touched. We did so by measuring how often participants would opt out of touches. Results show significant differences in opt-outs between touch zones on the front of the shirt. For both touchers and touchees, opt-outs occurred mostly in the upper chest touch zone. We also found significant differences in comfort ratings between touch zones on the front as well as on the back of the shirt. On the front, the upper chest and lower abdominal zones were the least comfortable touch zones. We found no gender effects on overall comfort ratings, suggesting the upper chest area was equally uncomfortable to males as it was to females. Interestingly, touching some areas rated as most uncomfortable produced a significantly greater calming effect on heart rate. Findings suggest participants were less comfortable with touches on the upper chest, the lower abdomen, and the lower back. We conclude that the most appropriate areas for touch sensors on a shirt are on the arms and shoulders, as well as on the upper back. Based on these findings, we created an interactive shirt for a proximity-based game of tag using Lumalive e-textile displays. This custom shirt features touch sensors located on the shoulder and lower arm regions of the shirt. / Thesis (Master, Computing) -- Queen's University, 2011-08-29 16:27:36.37
93

Minimally-invasive Wearable Sensors and Data Processing Methods for Mental Stress Detection

Choi, Jongyoon 2011 December 1900 (has links)
Chronic stress is endemic to modern society. If we could monitor our mental state, we may be able to develop insights about how we respond to stress. However, it is unfeasible to continuously annotate stress levels all the time. In the studies conducted for this dissertation, a minimally-invasive wearable sensor platform and physiological data processing methods were developed to analyze a number of physiological correlates of mental stress. We present a minimally obtrusive wearable sensor system that incorporates embedded and wireless communication technologies. The system is designed such that it provides a balance between data collection and user comfort. The system records the following stress related physiological and contextual variables: heart rate variability (HRV), respiratory activity, electrodermal activity (EDA), electromyography (EMG), body acceleration, and geographical location. We assume that if the respiratory influences on HRV can be removed, the residual HRV will be more salient to stress in comparison with raw HRV. We develop three signal processing methods to separate HRV into a respiration influenced and residual HRV. The first method consists of estimating respiration-induced portion of HRV using a linear system identification method (autoregressive moving average model with exogenous inputs). The second method consists of decomposing HRV into respiration-induced principal dynamic mode and residual using nonlinear dynamics decomposition method (principal dynamic mode analysis). The third method consists of splitting HRV into respiration-induced power spectrum and residual in frequency domain using spectral weighting method. These methods were validated on a binary discrimination problem of two psychophysiological conditions: mental stress and relaxation. The linear system identification method, nonlinear dynamics decomposition method, and spectral weighting method classified stress and relaxation conditions at 85.2 %, 89.2 %, and 81.5 % respectively. When tonic and phasic EDA features were combined with the linear system identification method, the nonlinear dynamics decomposition method, and the spectral weighting method, the average classification rates were increased to 90.4 %, 93.2 %, and 88.1 % respectively. To evaluate the developed wearable sensors and signal processing methods on multiple subjects, we performed case studies. In the first study, we performed experiments in a laboratory setting. We used the wearable sensors and signal processing methods to discriminate between stress and relaxation conditions. We achieved 81 % average classification rate in the first case study. In the second study, we performed experiments to detect stress in ambulatory settings. We collected data from the subjects who wore the sensors during regular daily activities. Relaxation and stress conditions were allocated during daily activities. We achieved a 72 % average classification rate in ambulatory settings. Together, the results show achievements in recognizing stress from wearable sensors in constrained and ambulatory conditions. The best results for stress detection were achieved by removing respiratory influence from HRV and combining features from EDA.
94

The Impact of Fitness Technology on Health Outcomes

Kelley, Megan C 01 January 2014 (has links)
Using 2014 data compiled from a sample of Claremont McKenna undergraduate students, I examine the effect that fitness technology (i.e., mobile and wearable technology) has on users' health outcomes. Specifically, I find no effect of mobile or wearable use on self-reported health. However, I do find some evidence of mobile use on weight but not wearable. Applying a basic OLS regression analysis, I show that mobile users tend to be heavier than non-mobile users irrespective of gender. Furthermore, I find that contemporaneous health on prior mobile use show higher weight levels compared to non- mobile prior users. Such findings provide evidence suggesting that mobile is ineffective in providing users with healthier outcomes.
95

Mediated and Mobile Communication for Experts

Nilsson, Marcus January 2014 (has links)
This thesis focuses on systems for mediated communication that run on mobile technology. The aim has been to give an answer to the question about what require- ments there are for situation awareness for domain experts when communication is secondary and supports the primary task. This thesis originated in a critical approach to the common practice of design- ing mediated communication systems with the face-to-face meeting as a guiding scenario. Instead, this thesis explores a design process that is based on the task and the strength of the technology itself. Different tasks do, of course, make different de- mands on a system, and a task that is strongly connected to the face-to-face meeting will probably be best served by a system that is designed from that perspective. Three cases that are presented in this thesis share three common themes that have characteristics that set them apart from the face-to-face meeting. The first theme is that the communication is a secondary task that is used to support a primary task. The second theme is that the cases involve domain experts active in the primary task. The use of experts implies that communication will be task- centered and also that the need for information to sustain a valuable situation awareness may be different from a person with less experience in the domain. The third theme is that all cases and the corresponding tasks benefit from some kind of situation awareness among the participants for optimal execution of the task. The three cases are based on: Wearable computers using mediated communication with wearable computers and how to handle interruptions for users of such computers Multidisciplinary team meetings improving access to patient information and enabling individual and group interaction with this information Trauma resuscitation giving a remote trauma expert’s correct and valuable in- formation while minimizing disturbance when supporting a local trauma re- suscitation team Prototypes are central in all three cases, and different prototypes have been designed and evaluated to validate the benefit of designing tools for communication that do not try to replicate the face-to-face meeting. The main findings in this thesis show that the shift of focus to the primary task when designing mediated communication systems has been beneficial in all three cases. A conflict between the secondary communication that is used to support sit- uation awareness and the primary task has been identified. Full situation awareness should therefore not be a goal in these designs but communication should support enough situation awareness to benefit the primary task with minimal disturbance to it. / <p>QC 20140221</p>
96

Development of an augmenting navigational cognition system

Yang, Ying. Chapman, Richard O. January 2005 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2005. / Abstract. Includes bibliographic references (p.73-80).
97

Development and evaluation of a terrestrial animal-borne video system for ecological research

Moll, Remington James, January 2008 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 12, 2008) Vita. Includes bibliographical references.
98

Wearable technology model to control and monitor hypertension during pregnancy

Lopez, Betsy Diamar Balbin, Aguirre, Jimmy Alexander Armas, Coronado, Diego Antonio Reyes, Gonzalez, Paola A. 27 June 2018 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this paper, we proposed a wearable technology model to control and monitor hypertension during pregnancy. We enhanced prior models by adding a series of health parameters that could potentially prevent and correct hypertension disorders in pregnancy. Our proposed model also emphasizes the application of real-time data analysis for the healthcare organization. In this process, we also assessed the current technologies and systems applications offered in the market. The model consists of four phases: 1. The health parameters of the patient are collected through a wearable device; 2. The data is received by a mobile application; 3. The data is stored in a cloud database; 4. The data is analyzed on real-time using a data analytics application. The model was validated and piloted in a public hospital in Lima, Peru. The preliminary results showed an increased-on number of controlled patients by 11% and a reduction of maternal deaths by 7%, among other relevant health factors that allowed healthcare providers to take corrective and preventive actions. / Revisión por pares
99

Novel sedentary behaviour measurement methods : application for self-monitoring in adults

Sanders, James P. January 2017 (has links)
With the introduction of the technological age, increasing mechanisation has led to labour saving devices which have all-but engineered physical activity out of our lives and sedentary behaviour has now become the default behaviour during waking hours. Interventions that previously focused on improving levels of physical activity are now attempting to concurrently increase levels of physical activity and decrease time spent in sedentary behaviour. One method that has shown promise in interventions to increase physical activity and healthy eating in adults is the behaviour change technique of self-monitoring. There is now a robust set of literature indicating self-monitoring as the most promising behaviour change technique in this area. Self-monitoring is tied inherently into the recent rise in wearable technology. These new devices have the ability to track a variety of behavioural and physiological parameters and immediately make the information returnable to the user via connected mobile applications. The potential pervasive nature of these technologies and their use of robust behaviour change techniques could make them a useful tool in interventions to reduce sedentary behaviour. Therefore the overall purpose of this three study dissertation was to identify and validate technology that can self-monitor sedentary behaviour and to determine its feasibility in reducing sedentary behaviour. Study 1 Purpose: The aim of this study was to review the characteristics and measurement properties of currently available self-monitoring devices for sedentary behaviour and/or physical activity. Methods: To identify technologies, four scientific databases were systematically searched using key terms related to behaviour, measurement, and population. Articles published through October 2015 were identified. To identify technologies from the consumer electronic sector, systematic searches of three Internet search engines were also performed through to October 1st, 2015. Results: The initial database searches identified 46 devices and the Internet search engines identified 100 devices yielding a total of 146 technologies. Of these, 64 were further removed because they were currently unavailable for purchase or there was no evidence that they were designed for, had been used in, or could readily be modified for self-monitoring purposes. The remaining 82 technologies were included in this review (73 devices self-monitored physical activity, 9 devices self-monitored sedentary time). Of the 82 devices included, this review identified no published articles in which these devices were used for the purpose of self-monitoring physical activity and/or sedentary behaviour; however, a number of technologies were found via Internet searches that matched the criteria for self-monitoring and provided immediate feedback on physical activity (ActiGraph Link, Microsoft Band, and Garmin Vivofit) and sedentary behaviour (activPAL VT, the LumoBack, and Darma). Conclusions: There are a large number of devices that self-monitor physical activity; however, there is a greater need for the development of tools to self-monitor sedentary time. The novelty of these devices means they have yet to be used in behaviour change interventions, although the growing field of wearable technology may facilitate this to change. Study 2 Purpose: The aim of this study was to examine the criterion and convergent validity of the LumoBack as a measure of sedentary behaviour compared to direct observation, the ActiGraph wGT3X+ and the activPAL under laboratory and free-living conditions in a sample of healthy adults. Methods: In the laboratory experiment, 34 participants wore a LumoBack, ActiGraph and activPAL monitor and were put through seven different sitting conditions. In the free-living experiment, a sub-sample of 12 participants wore the LumoBack, ActiGraph and activPAL monitor for seven days. Validity were assessed using Bland-Altman plots, mean absolute percentage error (MAPE), and intraclass correlation coefficient (ICC). T-test and Repeated Measures Analysis of Variance were also used to determine any significant difference in measured behaviours. Results: In the laboratory setting, the LumoBack had a mean bias of 76.2, 72.1 and -92.3 seconds when compared to direct observation, ActiGraph and activPAL, respectively, whilst MAPE was less than 4%. Furthermore, the ICC was 0.82 compared to the ActiGraph and 0.73 compared to the activPAL. In the free-living experiment, mean bias was -4.64, 8.90 and 2.34 seconds when compared to the activPAL for sedentary behaviour, standing time and stepping time respectively. Mean bias was -38.44 minutes when compared to the ActiGraph for sedentary time. MAPE for all behaviours were < 9%, and the ICC were all > 0.75. Conclusion: The LumoBack has acceptable validity and reliability as a measure of sedentary behaviour. Study 3 Purpose: The aim of this study was to explore the use of the LumoBack as a behaviour change tool to reduce sedentary behaviour in adults. Methods: Forty-two participants (≥25 years) who had an iPhone 4S or later model wore the LumoBack without any feedback for one week for baseline measures of behaviour. Participants then wore the LumoBack for a further five weeks whilst receiving feedback on sedentary behaviour via a sedentary vibration from the device and feedback on the mobile application. Sedentary behaviour, standing time, and stepping time were objectively assessed using the LumoBack. Differences in behaviour were determined between baseline, week 1 and week 5. Participant engagement with the LumoBack was determined using Mobile app analytics software. Results: There were no statistically significant differences in behaviour between baseline and the LumoBack intervention period (p > 0.05). Participants engaged most with the Steps card on the LumoBack app with peaks in engagement seen at week 5. Conclusion: This study indicates that using the LumoBack on its own was not effective in reducing sedentary behaviour in adults. Self-monitoring and feedback may need to be combined with other behaviour change strategies such as environmental restructuring to be effective. General Conclusion This thesis found that there are currently an abundance of technologies which self-monitors physical activity but a lack of devices which measuring sedentary behaviour. One such device, the LumoBack, has shown to have acceptable validity as a measure of sedentary behaviour. Whilst the use of the LumoBack as a behaviour change tool did not elicit any significant changes, its ability to be a pervasive behavioural intervention and the use of user-defined nudging can make the LumoBack, and other similar low cost, valid objective sedentary behaviour self-monitors key components in multi-faceted interventions.
100

Design of a Knee Exoskeleton for Gait Assistance

January 2018 (has links)
abstract: The world population is aging. Age-related disorders such as stroke and spinal cord injury are increasing rapidly, and such patients often suffer from mobility impairment. Wearable robotic exoskeletons are developed that serve as rehabilitation devices for these patients. In this thesis, a knee exoskeleton design with higher torque output compared to the first version, is designed and fabricated. A series elastic actuator is one of the many actuation mechanisms employed in exoskeletons. In this mechanism a torsion spring is used between the actuator and human joint. It serves as torque sensor and energy buffer, making it compact and safe. A version of knee exoskeleton was developed using the SEA mechanism. It uses worm gear and spur gear combination to amplify the assistive torque generated from the DC motor. It weighs 1.57 kg and provides a maximum assistive torque of 11.26 N·m. It can be used as a rehabilitation device for patients affected with knee joint impairment. A new version of exoskeleton design is proposed as an improvement over the first version. It consists of components such as brushless DC motor and planetary gear that are selected to meet the design requirements and biomechanical considerations. All the other components such as bevel gear and torsion spring are selected to be compatible with the exoskeleton. The frame of the exoskeleton is modeled in SolidWorks to be modular and easy to assemble. It is fabricated using sheet metal aluminum. It is designed to provide a maximum assistive torque of 23 N·m, two times over the present exoskeleton. A simple brace is 3D printed, making it easy to wear and use. It weighs 2.4 kg. The exoskeleton is equipped with encoders that are used to measure spring deflection and motor angle. They act as sensors for precise control of the exoskeleton. An impedance-based control is implemented using NI MyRIO, a FPGA based controller. The motor is controlled using a motor driver and powered using an external battery source. The bench tests and walking tests are presented. The new version of exoskeleton is compared with first version and state of the art devices. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2018

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