Brain Computer Interface for Emergency Virtual Voice

Brain computer interface (BCI) is one of the thriving emergent technology which acts as an interface between a brain and an external device. BCI for speech communication is acquiring recognition in various fields. Speech is one of the most natural ways to express thoughts and feelings by articulate vocal sounds. The purpose of this study is to restore communication ability of the people suffering from severe muscular disorders like amyotrophic lateral sclerosis (ALS), stroke which causes paralysis, locked-in syndrome, tetraplegia and Myasthenia gravis. They cannot interact with their environment even though their intellectual capabilities are intact. Our work attempts to provide summary of the research articles being published in reputed journals which lead to the investigation of published BCI articles, BCI prototypes, Bio-Signals for BCI, intent of the articles, target applications, classification techniques, algorithms and methodologies, BCI system types. Thus, the result of detailed survey presents an outline of available studies, recent results and looks forward to future developments which provides a communication pathway for paralyzed patients to convey their needs

Current roles of artificial intelligence in ophthalmology

Artificial intelligence (AI) studies are increasingly reporting successful results in the diagnosis and prognosis prediction of ophthalmological diseases as well as systemic disorders. The goal of this review is to detail how AI can be utilized in making diagnostic predictions to enhance the clinical setting. It is crucial to keep improving methods that emphasize clarity in AI models. This makes it possible to evaluate the information obtained from ocular imaging and easily incorporate it into therapeutic decision-making procedures. This will contribute to the wider acceptance and adoption of AI-based ocular imaging in healthcare settings combining advanced machine learning and deep learning techniques with new developments. Multiple studies were reviewed and evaluated, including AI-based algorithms, retinal images, fundus and optic nerve head (ONH) photographs, and extensive expert reviews. In these studies, carried out in various countries and laboratories of the world, it is seen those complex diagnoses, which can be detected systemic diseases from ophthalmological images, can be made much faster and with higher predictability, accuracy, sensitivity, and specificity, in addition to ophthalmological diseases, by comparing large numbers of images and teaching them to the computer. It is now clear that it can be taken advantage of AI to achieve diagnostic certainty. Collaboration between the fields of medicine and engineering foresees promising advances in improving the predictive accuracy and precision of future medical diagnoses achieved by training machines with this information. However, it is important to keep in mind that each new development requires new additions or updates to various social, psychological, ethical, and legal regulations

Advanced bioelectrical signal processing methods: Past, present and future approach - Part III: Other biosignals

Analysis of biomedical signals is a very challenging task involving implementation of various advanced signal processing methods. This area is rapidly developing. This paper is a Part III paper, where the most popular and efficient digital signal processing methods are presented. This paper covers the following bioelectrical signals and their processing methods: electromyography (EMG), electroneurography (ENG), electrogastrography (EGG), electrooculography (EOG), electroretinography (ERG), and electrohysterography (EHG).Web of Science2118art. no. 606

Development and validation of a digital quantitative orthoptics workstation

The objective of the research is to provide the clinician with a simple system for making quantitative measurements that is comparable to the services of a skilled orthoptist. As many optometrists do not possess the necessary equipment for making such assessments, this technology would significantly enhance their referral capabilities. Reviews of the tests involved and instruments available are detailed in Chapter II and III. Chapter IV presents the various validation experiments carried out on the Tobii X120 eye tracker, concentrating on technical specifications such as, linearity range, optimum measurement distance and setup (with and without chin rest). We also investigated the effect of wearing different types of lens materials and pupil size measurements on the eye tracker system. We established the inter-examiner agreement of cover test measurements on groups of non-strabismic and strabismic subjects. This study, as detailed in Chapter V, involved collaboration with two clinical orthoptists. We found a good inter-examiner agreement for both the non-strabismic and strabismic cover tests. We further investigated the use of the eye tracker in providing more reliable findings for cover test measurements as compared to the conventional cover test (Chapter VI). Finally we extended the investigation to a number of different clinical subjects attending the Bristol Eye Hospital (Chapter VII) in order to evaluate our purpose-developed monocular calibration routine. Performing quantitative eye movement analysis will provide valuable additional information in any clinical investigation of patients with ophthalmological and/or neurological disorders, leading to greater precision in diagnosis. Traditional methods for the evaluation of oculomotor disorders rely on the diagnostic and therapeutic judgements by the examining clinicians and subjective responses from the patient. However, the use of currently available eye movement recording system will provide valuable alternatives for obtaining more objective and quantitative measurements

Stretchable Surface Electromyography Electrode Array Based on Liquid Metal and Conductive Polymer

Electromyography (EMG), the science of detecting and interpreting muscle electrical activity, plays a crucial role in clinical diagnostics and research. It enables assessment of muscle function, detection of abnormalities, and monitoring of rehabilitation progress. However, the current use of EMG devices is primarily limited to clinical settings, preventing its potential to revolutionize personal health management. If surface electromyography (sEMG) electrodes are stretchable, arrayed, reusable and able to continuously record, their applications for personal health management are broadened. Existing electrodes lack these essential features, hampering their widespread adoption. This thesis addresses these limitations by designing an adhesive dry electrode using tannic acid, polyvinyl alcohol, and PEDOT:PSS (TPP). Through meticulous optimization, TPP electrodes offer superior stretchability and adhesiveness compared to conventional Ag/AgCl electrodes. This ensures stable and long-term skin contact for recording. Furthermore, a metal-polymer electrode array patch (MEAP) is introduced, featuring liquid metal (LM) circuits and TPP electrodes. MEAPs exhibit better conformability than current commercial arrays, resulting in higher signal quality and stable recordings, even during significant skin deformations caused by muscle movements. Manufactured using scalable screen-printing, MEAPs combine stretchable materials and array architecture for real-time monitoring of muscle stress, fatigue, and tendon displacement. They hold great promise in reducing muscle and tendon injuries and enhancing performance in both daily exercise and professional sports. In addition, a pilot study compares MEAP performance in clinical electrodiagnostics with needle electrodes, demonstrating the non-invasive advantage of MEAP by successfully recording the signals from the same motor unit as the needle. These advancements position MEAP at the forefront of the EMG field, poised to drive breakthroughs in electrodiagnostics, personalized medicine, sports science, and rehabilitation

DEVELOPMENT OF NEUROPHYSIOLOGICAL APPROACHES FOR MONITORING AND INTERVENING MENTAL FATIGUE

Ph.DDOCTOR OF PHILOSOPH

Are Natural Killer Cells Novel Mediators of The Effects of Cannabidiol on Mental Health, Sleep Quantity, Sleep Quality, And Immune Function?

Cannabidiol (CBD) has increased in popularity since the United States Farm Bill legalized hemp production in 2018 and is now projected to become a $24.4 billion dollar industry by 2025. Since its legalization, CBD is thought to be an antiepileptic, anxiolytic, and antipsychotic, as well as an agent to improve mental health, quality of life, aspects of sleep and immune function. However, many of these claims lack scientific evidence. The purpose of this randomized, double blind, placebo-controlled trial was to determine the effects of an 8-week CBD intervention on measures of mental health, sleep quantity, sleep quality, and natural killer cell (NKC) quantity and function. Researchers hypothesized that following an 8-week CBD intervention, participants consuming CBD will experience improvements in measures of mental health, increased sleep quantity and quality, and will have an increased percentage of NKC in peripheral blood, as well as decreases in NKC function determined by a measure of K562 cell viability. Physically active men and women (18-45y) were randomly assigned to placebo (CN, n=12) or CBD (CB, n=15) groups. Participants consumed a capsulized control; coconut derived medium chain triglycerides (MCT; 225mg/day) or CBD (50mg/day with 175mg of MCT) daily for 8 weeks. Before and after the intervention period, participants completed measures of mental health, sleep analysis (FITBIT), body size, body composition (BodPod), a peripheral blood draw, anaerobic fitness (Wingate), aerobic fitness (VO2max), 1 repetition strength testing (1RM). Peripheral blood mononuclear cells (PBMC) were extracted from peripheral blood to determine immune cell population percentages, and natural killer cell (NKC) cytotoxicity. Immune population percentage measures involved, staining the cells with anti-CD3 and anti-CD56 for the determination of NKC (CD3-/CD56+), T cells (CD3+/CD56-) and natural killer T cells (NKT; CD3+/CD56+). NKC cytotoxicity analysis involved co-incubated of PBMC with K562 leukemia cells for 4 hours at ratios of 1:1, 5:1, 10:1, and 20:1 effector: target cell (E:T). K562 cell viability was determined using median fluorescence intensity using a flow cytometer. Data are presented as mean ± standard deviation with significance set at α=0.05. An independent-samples T-test was ran on all outcome measures at the pre intervention time point to ensure homogeneity between groups, and a 2 (group) x 2 (time) analysis of variance (ANOVA) was used to identify any interactions or main effects that occurred throughout the intervention. At the pre intervention time points, there were no significant differences between groups with respect to participant anthropometrics or exercise performance measures (age: 26.1 ± 6.2y; height: 169 ± 8.8cm; weight: 71.6 ± 12.8kg; lean body mass: 55.8 ± 11.3kg; body fat: 21.8 ± 8.3%; Peak Power: 647.8 ± 169.9W; Mean Power: 459.1 ± 121.1W; Anaerobic Fatigue: 56.9 ±7.2%; VO2Peak: 45.0 ± 7.6ml/kg/min; 1RM Squat: 88.2 31.4kg; 1RM Bench:61.43 28.44kg); however, VO2Peak significantly decreased after 8-weeks regardless of intervention group (p=0.038; Pre: 45.05 ± 7.61 Post: 43.75 ± 7.34ml/kg/min). There were no significant differences pre to post intervention between groups in measures of mental health (QOL; Pre: 9.49 ± 1.82 Post:19.81 ± 1.42; PFS; Pre: 3.22 ± 1.58 Post:2.74 ± 1.58; BDI; Pre: 4.56 ± 3.83 Post: 4.44 ± 3.72; GAD-7; Pre: 6.3 ± 6.0 Post: 4.9 ± 4.3), sleep quantity (TST; Pre: 386.75 ± 67.69 Post: 388.92 ± 57.89min) or sleep quality (WE; Pre: 26.44 ± 7.53 Post: 26.16 ± 7.70; SE; Pre: 88.41 ± 1.46 Post: 88.02 ± 1.93%). Furthermore, the fraction of NKC within 1x106 peripheral blood mononuclear cells remained unchanged (Pre: 8.44 ± 5.34% Post: 8.79 ± 4.12%), following the intervention period. Finally, there were no differences in K562 cell viability assessed through mean and median fluorescence intensity of Calcein-AM, following an 8-week CBD intervention. Eight weeks of CBD (50mg/day) did not alter measures of mental health, sleep quantity or quality, NKC percentage in peripheral blood or NKC function. This suggests that CBD may not alter mental health, sleep quantity, sleep quality, NKC percentage in peripheral blood or NKC cytolytic function

Advances in Clinical Neurophysiology

Including some of the newest advances in the field of neurophysiology, this book can be considered as one of the treasures that interested scientists would like to collect. It discusses many disciplines of clinical neurophysiology that are, currently, crucial in the practice as they explain methods and findings of techniques that help to improve diagnosis and to ensure better treatment. While trying to rely on evidence-based facts, this book presents some new ideas to be applied and tested in the clinical practice. Advances in Clinical Neurophysiology is important not only for the neurophysiologists but also for clinicians interested or working in wide range of specialties such as neurology, neurosurgery, intensive care units, pediatrics and so on. Generally, this book is written and designed to all those involved in, interpreting or requesting neurophysiologic tests

EEG-based investigation of cortical activity during Postural Control

The postural control system regulates the ability to maintain a stable upright stance and to react to changes in the external environment. Although once believed to be dominated by low-level reflexive mechanisms, mounting evidence has highlighted a prominent role of the cortex in this process. Nevertheless, the high-level cortical mechanisms involved in postural control are still largely unexplored. The aim of this thesis is to use electroencephalography, a widely used and non-invasive neuroimaging tool, to shed light on the cortical mechanisms which regulate postural control and allow balance to be preserved in the wake of external disruptions to one’s quiet stance. EEG activity has been initially analysed during a well-established postural task - a sequence of proprioceptive stimulations applied to the calf muscles to induce postural instability – traditionally used to examine the posturographic response. Preliminary results, obtained through a spectral power analysis of the data, highlighted an increased activation in several cortical areas, as well as different activation patterns in the two tested experimental conditions: open and closed eyes. An improved experimental protocol has then been developed, allowing a more advanced data analysis based on source reconstruction and brain network analysis techniques. Using this new approach, it was possible to characterise with greater detail the topological structure of cortical functional connections during the postural task, as well as to draw a connection between quantitative network metrics and measures of postural performance. Finally, with the integration of electromyography in the experimental protocol, we were able to gain new insights into the cortico-muscular interactions which direct the muscular response to a postural challenge. Overall, the findings presented in this thesis provide further evidence of the prominent role played by the cortex in postural control. They also prove how novel EEG-based brain network analysis techniques can be a valid tool in postural research and offer promising perspectives for the integration of quantitative cortical network metrics into clinical evaluation of postural impairment.Kerfi stöðustjórnunar er afturvirkt stýrikerfi sem vinnur stöðugt að því að viðhalda uppréttri stöðu líkamans og bregðast við ójafnvægi. Vaxandi þekking á undanförnum árum hefur lýst því að úrvinnsla þessara upplýsinga á sér stað á öllum stigum miðtaugakerfisins, þá sérstaklega barkarsvæði heilahvela. Engu að síður, er nákvæmu hlutverk heilabarkar við stöðustjórnun enn óljóst að mörgu leyti. Tilgangur þessa verkefnis var að rannsaka nánar hlutverk heilabarkar við truflun og áreiti á kerfi stöðustjórnarinnar, með notkun hágæða heilarafrits (EEG). Við byrjuðum á því að mæla heilarit einstaklinga meðan á þekktri líkamsstöðu-æfingu stóð, til þess að skoða svörun líkamans við röð titringsáreita sem beitt var á kálfavöðvana til að framkalla óstöðugleika. Bráðabirgðaniðurstöður fengnar með PSD-aðferð (power spectral analysis) leiddu í ljós aukna virkni á ákveðnum svæðum í heilaberki og sérstakt viðbragðsmynstur við að framkvæma æfinguna, annars vegar með lokuð augu og hins vegar opin augu. Rannsókn okkar hélt áfram með nýrri og þróaðari tækni sem gerði okkur kleift að framkvæma fullkomnari greiningaraðferðir til að túlka, greina og skilja merki frá heilaritnu. Með fullkomnari greiningaraðferðum var hægt að lýsa með nákvæmari hætti staðfræðilega uppbyggingu starfrænna tenginga í heilaberki meðan á líkamsstöðu æfingunni stóð, sem og að draga tengsl á milli megindlegra netmælinga og mælinga á líkamsstöðu. Að lokum bætist við vöðvarafritsmæling við aðferðafræðina, sem gaf okkur innsýn inn í samskipti heilabarka og vöðvana sem stýra vöðvaviðbrögðum og viðhalda líkamsstöðu við utanaðkomandi áreiti. Á heildina litið gefa niðurstöðurnar sem settar eru fram í þessari ritgerð enn sterkari vísbendingar um það áberandi hlutverk sem heilabörkurinn gegnir við stjórnun líkamsstöðu. Niðurstöðurnar sanna einnig hvernig ný aðferð á greiningu á tengslaneti heilans sem byggir á heilariti getur verið gilt tæki í líkamsstöðu rannsóknum og er nytsamlegt tól fyrir mælingar á heilakerfisneti í klínískt mat á skerðingu líkamsstöðu

Multimodal Wearable Sensors for Human-Machine Interfaces

Certain areas of the body, such as the hands, eyes and organs of speech production, provide high-bandwidth information channels from the conscious mind to the outside world. The objective of this research was to develop an innovative wearable sensor device that records signals from these areas more conveniently than has previously been possible, so that they can be harnessed for communication. A novel bioelectrical and biomechanical sensing device, the wearable endogenous biosignal sensor (WEBS), was developed and tested in various communication and clinical measurement applications. One ground-breaking feature of the WEBS system is that it digitises biopotentials almost at the point of measurement. Its electrode connects directly to a high-resolution analog-to-digital converter. A second major advance is that, unlike previous active biopotential electrodes, the WEBS electrode connects to a shared data bus, allowing a large or small number of them to work together with relatively few physical interconnections. Another unique feature is its ability to switch dynamically between recording and signal source modes. An accelerometer within the device captures real-time information about its physical movement, not only facilitating the measurement of biomechanical signals of interest, but also allowing motion artefacts in the bioelectrical signal to be detected. Each of these innovative features has potentially far-reaching implications in biopotential measurement, both in clinical recording and in other applications. Weighing under 0.45 g and being remarkably low-cost, the WEBS is ideally suited for integration into disposable electrodes. Several such devices can be combined to form an inexpensive digital body sensor network, with shorter set-up time than conventional equipment, more flexible topology, and fewer physical interconnections. One phase of this study evaluated areas of the body as communication channels. The throat was selected for detailed study since it yields a range of voluntarily controllable signals, including laryngeal vibrations and gross movements associated with vocal tract articulation. A WEBS device recorded these signals and several novel methods of human-to-machine communication were demonstrated. To evaluate the performance of the WEBS system, recordings were validated against a high-end biopotential recording system for a number of biopotential signal types. To demonstrate an application for use by a clinician, the WEBS system was used to record 12‑lead electrocardiogram with augmented mechanical movement information