126 research outputs found

    Modeling and Fabrication of Smart Robotic Wheelchair Instructed by Head Gesture

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    The confronting problem faced by the handicapped, paralyzed, disabled, and quadriplegic people is their independent mobility. They need external assistance to perform their daily life activities. This paper aims to solve that problem by smart designing and deployment of the robotic wheelchair for those who cannot perform their voluntary activities and movements. The proposed automated wheelchair comprises two parts; the first part is the user's helmet that works as a master device, and the second part is a slave device, a smart wheelchair. The master device consists of an accelerometer, microcontroller, and wireless transmitter, in which the Accelerometer recognizes the movements of the user's head and transmits the signal according to the tiltation of the user's head. Besides this, the slave device consists of a wireless receiver, microcontroller, Gyroscope, power MOSFETs, and DC geared motors mounted on a smart wheelchair, which response as per the instructions of the master device. Furthermore, the paper also provides a brief construction of this mechatronic and amphibian system using static and dynamic equations

    CES-513 Stages for Developing Control Systems using EMG and EEG Signals: A survey

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    Bio-signals such as EMG (Electromyography), EEG (Electroencephalography), EOG (Electrooculogram), ECG (Electrocardiogram) have been deployed recently to develop control systems for improving the quality of life of disabled and elderly people. This technical report aims to review the current deployment of these state of the art control systems and explain some challenge issues. In particular, the stages for developing EMG and EEG based control systems are categorized, namely data acquisition, data segmentation, feature extraction, classification, and controller. Some related Bio-control applications are outlined. Finally a brief conclusion is summarized.

    Multimodal Analysis of Pilot’s Fatigue During a Multi-Phase Flight Mission

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    One troubling threat to successful flight missions is attributed to fatigue induced and errors. Therefore, discovering effective methods to assess fatigue has been a major topic discussed by professional pilots and aviation experts. Fatigue is a major human factor related issue in aviation and currently subject to increased discussion by aviation administrations and professional pilots. Therefore, effective assessment of fatigue will provide opportunities to reduce the risk of fatigue-induced errors. Currently available subjective measures that assess fatigue can be somewhat affected by external and internal factors, that might cause biased judgment. Therefore, Psychomotor Vigilance Task (PVT), which provides objective measures, can be a viable approach to measure fatigue. In addition, eye movement analysis might augment the fatigue assessment, because eye movement analysis is an unobtrusive approach that does not require direct contact with the participant and can be measured for a long duration. However, it is unknown how eye movement characteristics are correlated with fatigue. In this research, a multi-modal fatigue measurement framework was developed by combining the PVT analysis with eye movement analysis. In detail, PVT measures (i.e., reaction time, lapses & false starts) and eye movement characteristics (i.e., eye fixation duration, pupil size, number of eye fixations, gaze entropy) were measured to determine pilots’ fatigue level under different flight conditions. The results show that significant correlations exist among the eye movement characteristics and the PVTs measures. The proposed multi-modal approach show promise on evaluating pilot fatigue in near real time, which in turn might enable timely recovery interventions

    USSR Space Life Sciences Digest, issue 32

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    This is the thirty-second issue of NASA's USSR Space Life Sciences Digest. It contains abstracts of 34 journal or conference papers published in Russian and of 4 Soviet monographs. Selected abstracts are illustrated with figures and tables from the original. The abstracts in this issue have been identified as relevant to 18 areas of space biology and medicine. These areas include: adaptation, aviation medicine, biological rhythms, biospherics, cardiovascular and respiratory systems, developmental biology, exobiology, habitability and environmental effects, human performance, hematology, mathematical models, metabolism, microbiology, musculoskeletal system, neurophysiology, operational medicine, and reproductive system

    Eye Movement and Pupil Measures: A Review

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    Our subjective visual experiences involve complex interaction between our eyes, our brain, and the surrounding world. It gives us the sense of sight, color, stereopsis, distance, pattern recognition, motor coordination, and more. The increasing ubiquity of gaze-aware technology brings with it the ability to track gaze and pupil measures with varying degrees of fidelity. With this in mind, a review that considers the various gaze measures becomes increasingly relevant, especially considering our ability to make sense of these signals given different spatio-temporal sampling capacities. In this paper, we selectively review prior work on eye movements and pupil measures. We first describe the main oculomotor events studied in the literature, and their characteristics exploited by different measures. Next, we review various eye movement and pupil measures from prior literature. Finally, we discuss our observations based on applications of these measures, the benefits and practical challenges involving these measures, and our recommendations on future eye-tracking research directions

    Learning Mental States from Biosignals

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    As computing technology evolves, users perform more complex tasks with computers. Hence, users expect from user interfaces to be more proactive than reactive. A proactive interface should anticipate the user’s intentions and take the right action without requiring a user command. The crucial first step for such an interface is to infer the user’s mental state, which gives important cues about user intentions. This thesis consists of several case studies on inferring mental states of computer users.  Biosensing technology provides a variety of hardware tools for measuring several aspects of human physiology, which is correlated with emotions and mental processes. However, signals gathered with biosensors are notoriously noisy. The mainstream approach to overcome this noise is either to increase the signal precision by expensive and stationary sensors or to control the experiment setups more heavily. Both of these solutions undermine the usability of the developed methods in real-life user interfaces. In this thesis, machine learning is used as an alternative strategy for handling the biosignal noise in mental state inference. Computer users have been monitored under loosely controlled experiment setups by cheap and inaccurate biosensors, and novel machine learning models that infer mental states such as affective state, mental workload, relevance of a real-world object, and auditory attention are built. The methodological contributions of the thesis are mainly on multi-view learning and multitask learning. Multi-view learning is used for integrating signals of multiple biosensors and the stimuli. Multitask learning is used for inferring multiple mental states at once, and for exploiting the inter-subject similarities for higher prediction accuracy. A novel multitask learning algorithm that transfers knowledge across multi-view learning tasks is introduced. Another novelty is a Bayesian factor analyzer with a time-dependent latent space that captures the dynamic nature of biosignals better than methods that assume independent samples. The overall outcome of the thesis is that it is feasible to predict mental states from unobtrusive biosensors with reasonable accuracy using state-of-the-art machine learning models

    Empirical Modeling of Asynchronous Scalp Recorded and Intracranial EEG Potentials

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    A Brain-Computer Interface (BCI) is a system that allows people with severe neuromuscular disorders to communicate and control devices using their brain signals. BCIs based on scalp-recorded electroencephalography (s-EEG) have recently been demonstrated to provide a practical, long-term communication channel to severely disabled users. These BCIs use time-domain s-EEG features based on the P300 event-related potential to convey the user\u27s intent. The performance of s-EEG-based BCIs has generally stagnated in recent years, and high day-to-day performance variability exists for some disabled users. Recently intracranial EEG (i-EEG), which is recorded from the cortical surface or the hippocampus, has been successfully used to control BCIs in experimental settings. Because these recordings are closer to the sources of the neural activity, i-EEG provides superior signal-to-noise ratio, spatial resolution, and broader bandwidth compared to s-EEG. However, because i-EEG requires surgery and the long-term efficacy for BCIs must still be explored, this approach is still not an option for patients. In order to improve s-EEG BCI performance, it is important understand the underlying brain phenomena and exploit the relationships between the s-EEG and generally superior i-BEG signals. Because the human head acts as a volume conductor consisting of the brain, cerebrospinal fluid, skull, and scalp tissue, linear mathematical models can be used to relate s-EEG and i-EEG. This dissertation presents unique s-EEG and i-EEG data that were recorded from the same subjects and used to develop novel empirical models to estimate s-EEG from i-EEG. These new empirical models can be used to better understand the sources and propagation of the relevant neural activity, as well as to validate existing theoretical volume conduction models. It is envisioned that this knowledge will help to advance algorithms for improving s-EEG BCI performance

    Contributions to the study of Austism Spectrum Brain conectivity

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    164 p.Autism Spectrum Disorder (ASD) is a largely prevalent neurodevelopmental condition with a big social and economical impact affecting the entire life of families. There is an intense search for biomarkers that can be assessed as early as possible in order to initiate treatment and preparation of the family to deal with the challenges imposed by the condition. Brain imaging biomarkers have special interest. Specifically, functional connectivity data extracted from resting state functional magnetic resonance imaging (rs-fMRI) should allow to detect brain connectivity alterations. Machine learning pipelines encompass the estimation of the functional connectivity matrix from brain parcellations, feature extraction and building classification models for ASD prediction. The works reported in the literature are very heterogeneous from the computational and methodological point of view. In this Thesis we carry out a comprehensive computational exploration of the impact of the choices involved while building these machine learning pipelines
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