65 research outputs found

    Diagnosis of Parkinson's Disease Based on Voice Signals Using SHAP and Hard Voting Ensemble Method

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    Background and Objective: Parkinson's disease (PD) is the second most common progressive neurological condition after Alzheimer's, characterized by motor and non-motor symptoms. Developing a method to diagnose the condition in its beginning phases is essential because of the significant number of individuals afflicting with this illness. PD is typically identified using motor symptoms or other Neuroimaging techniques, such as DATSCAN and SPECT. These methods are expensive, time-consuming, and unavailable to the general public; furthermore, they are not very accurate. These constraints encouraged us to develop a novel technique using SHAP and Hard Voting Ensemble Method based on voice signals. Methods: In this article, we used Pearson Correlation Coefficients to understand the relationship between input features and the output, and finally, input features with high correlation were selected. These selected features were classified by the Extreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), Gradient Boosting, and Bagging. Moreover, the Hard Voting Ensemble Method was determined based on the performance of the four classifiers. At the final stage, we proposed Shapley Additive exPlanations (SHAP) to rank the features according to their significance in diagnosing Parkinson's disease. Results and Conclusion: The proposed method achieved 85.42% accuracy, 84.94% F1-score, 86.77% precision, 87.62% specificity, and 83.20% sensitivity. The study's findings demonstrated that the proposed method outperformed state-of-the-art approaches and can assist physicians in diagnosing Parkinson's cases

    Developing a large scale population screening tool for the assessment of Parkinson's disease using telephone-quality voice

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    Recent studies have demonstrated that analysis of laboratory-quality voice recordings can be used to accurately differentiate people diagnosed with Parkinson's disease (PD) from healthy controls (HC). These findings could help facilitate the development of remote screening and monitoring tools for PD. In this study, we analyzed 2759 telephone-quality voice recordings from 1483 PD and 15321 recordings from 8300 HC participants. To account for variations in phonetic backgrounds, we acquired data from seven countries. We developed a statistical framework for analyzing voice, whereby we computed 307 dysphonia measures that quantify different properties of voice impairment, such as, breathiness, roughness, monopitch, hoarse voice quality, and exaggerated vocal tremor. We used feature selection algorithms to identify robust parsimonious feature subsets, which were used in combination with a Random Forests (RF) classifier to accurately distinguish PD from HC. The best 10-fold cross-validation performance was obtained using Gram-Schmidt Orthogonalization (GSO) and RF, leading to mean sensitivity of 64.90% (standard deviation, SD 2.90%) and mean specificity of 67.96% (SD 2.90%). This large-scale study is a step forward towards assessing the development of a reliable, cost-effective and practical clinical decision support tool for screening the population at large for PD using telephone-quality voice.Comment: 43 pages, 5 figures, 6 table

    Accurate telemonitoring of Parkinson's disease symptom severity using nonlinear speech signal processing and statistical machine learning

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    This study focuses on the development of an objective, automated method to extract clinically useful information from sustained vowel phonations in the context of Parkinson’s disease (PD). The aim is twofold: (a) differentiate PD subjects from healthy controls, and (b) replicate the Unified Parkinson’s Disease Rating Scale (UPDRS) metric which provides a clinical impression of PD symptom severity. This metric spans the range 0 to 176, where 0 denotes a healthy person and 176 total disability. Currently, UPDRS assessment requires the physical presence of the subject in the clinic, is subjective relying on the clinical rater’s expertise, and logistically costly for national health systems. Hence, the practical frequency of symptom tracking is typically confined to once every several months, hindering recruitment for large-scale clinical trials and under-representing the true time scale of PD fluctuations. We develop a comprehensive framework to analyze speech signals by: (1) extracting novel, distinctive signal features, (2) using robust feature selection techniques to obtain a parsimonious subset of those features, and (3a) differentiating PD subjects from healthy controls, or (3b) determining UPDRS using powerful statistical machine learning tools. Towards this aim, we also investigate 10 existing fundamental frequency (F_0) estimation algorithms to determine the most useful algorithm for this application, and propose a novel ensemble F_0 estimation algorithm which leads to a 10% improvement in accuracy over the best individual approach. Moreover, we propose novel feature selection schemes which are shown to be very competitive against widely-used schemes which are more complex. We demonstrate that we can successfully differentiate PD subjects from healthy controls with 98.5% overall accuracy, and also provide rapid, objective, and remote replication of UPDRS assessment with clinically useful accuracy (approximately 2 UPDRS points from the clinicians’ estimates), using only simple, self-administered, and non-invasive speech tests. The findings of this study strongly support the use of speech signal analysis as an objective basis for practical clinical decision support tools in the context of PD assessment.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Experiences of mutuality in the spousal relationship in advanced Parkinson’s Disease from the perspective of the caregiving partner

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    Introduction: Parkinson’s Disease (PD) is a chronic and degenerative illness with a long trajectory involving multiple physical, cognitive, and emotional changes. In contrast to the holistic approach of palliative care, medical visits for PD patients tend to focus primarily on physical symptoms. Little attention may be paid to the psychosocial effects of PD, such as relational satisfaction and emotional and spiritual well-being of both patient and family. As illness advances, dependence on others occurs; in many if not most cases, the spouse is the primary caregiver. While research has been conducted to examine burden of care for PD spouses, the literature reveals little on mutuality, which concerns the quality of the relationship. Method: This study was conducted with spousal caregivers of PD patients with advanced illness at Hoehn & Yahr stages 4 and 5. Twelve caregiving spouses to partners with advanced PD participated in a single face-to-face semi-structured interview in this qualitative hermeneutic phenomenology study. van Manen’s approach to data analysis and writing for hermeneutic phenomenology was utilised, incorporating the four lifeworld existentials of spatiality, temporality, corporeality, and relationality. Results: Participants’ challenges to mutuality included limited enjoyable shared activities, living with a “stranger”, little fun, and resentment about PD. Loss of identity, ambiguous loss, and searching for meaning are challenges for caregiving spouses caring for an advanced PD partner; nevertheless most participants want to be with their spouse. Conclusion: Understanding how PD affects the marital relationship is crucial for health professionals to provide a palliative approach to both partners living with this unwelcome “intruder” in their lives

    Models and Analysis of Vocal Emissions for Biomedical Applications

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    The Models and Analysis of Vocal Emissions with Biomedical Applications (MAVEBA) workshop came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy

    A study of psychological distress in caregivers of Parkinson's Disease patients

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    The aim of this PhD was to extend current research on caregiving by investigating outcomes for a large group of caregivers who have been relatively neglected in the caregiving literature. The focus of the research was to identify predictors of psychological distress in caregivers of Parkinson’s disease (PD) patients using a longitudinal design and quantitative and qualitative data. In chapter one, Parkinson’s disease is described in sufficient detail to illustrate the demands of PD caregivers. In chapter two, the caregiving literature is reviewed. The major factors in the prediction of caregiver distress are covered and various hypotheses are made with respect to Parkinson’s disease caregiving. It was hypothesised that the much greater physical demands placed on those who give care to PD patients would mean that the predictors of negative outcomes may not be the same as the predictors of distress in other caregiving situations. In chapter three, current models of caregiving are presented and evaluated. As caregiving can be perceived as being a job, theories from the organisational stress literature as well as the caregiving literature were used to conceptualise PD caregiving in a simple model. From the organisational literature, it was hypothesised that the interaction of job demand and discretion would predict distress, and that uncertainty, or lack of knowledge, would be a predictor of distress. A methods section follows in which the choice of measures is discussed. In this research, caregiver distress was not seen as a global concept, but rather it was reduced to six qualitatively distinct components - burden from impact on relationship, burden from impact on social life, emotional burden, depression, poor psychological health and low life satisfaction. Patients and caregivers were tested on two occasions. The tests and interviews took place approximately fourteen months apart. 83 patients and caregivers took part in phase I; 56 patients and caregivers took part in phase II. The main cause of atrophy was death. Phase I results are presented in chapter four, and phase II results are presented in chapter five. The main findings were (i) that it was correct to reduce caregiver distress for the predictor variables accounting for the maximum variance were different for each aspect of distress, (ii) patient variables - particularly physical demand and cognitive demand - were found to be important predictors of PD caregiver distress, (iii) caregiver personality and coping style had a major influence on caregiving outcomes, (iv) although there was a measurable progression of PD from phase I to phase II, there was no increase in distress in the same period, (v) there were moderator variables that did not directly predict distress but were nevertheless important to a model of PD caregiving, (vi) contrary to the hypothesis, the more that caregivers knew about PD, the greater their distress. It was suggested that this is a result of having to learn about the illness situation by experience. Qualitative data is presented in chapter six to describe carers’ experiences of Parkinson’s disease. Summary statistics and selected case studies are used to illustrate important themes, such as onset, personality change and job demand. The results are discussed in chapter seven and it is concluded that there are predictors of distress that hold across caregiving situations. These tend to be caregiver variables such as personality and coping style. But there are also predictors of distress that are specific to Parkinson’s disease, such as job demand which, unlike in most other caregiving situations, was the biggest predictor of two aspects of distress. It was concluded that a general model of caregiving is not appropriate, and a revised simple model of Parkinson’s disease caregiving is presented

    Student Research Colloquium Proceedings 2009

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    2009 Student Research Colloquium proceedings include the following: a schedule of the day\u27s events, acknowledgement of research sponsors, the day\u27s program, conference presentation abstracts, student presenter index, research sponsor index, planning committee, poster and paper presentation judges, registration desk, sponsors, and donors, map of Atwood Memorial Center. Keynote address on greenhouse gases, global demand for energy, and tomrorow\u27s technology to address these issues given by Dr. Sean Garrick, Associate Professor, Department of Mechanical Engineering, University of Minnesota. Sustainability Panel Discussion panelists: Dr. Anthony Akubue, Professor, Environmental and Technological Studies, St. Cloud State University; Dr. Sean Garrick, Associate Professor, Mechanical Engineering, University of Minnesota; Valerie Knopp, Assistant Director of Financial Aid, Offices of Scholarships and Financial Aid, St Cloud State University; Teresa A. Lamo-Nelson, Doctoral Candidate, Higher Education Administration, St. Cloud State University; Angela Olson, Assistant Professor, Aviation, St. Cloud State University; Dr. Tracy E. Ore, Associate Professor/Coordinator, Sociology and Anthropology/St Cloud State University Community Garden, Dr. Mitch Bender (Moderator), Associate Professor, Environmental and Technological Studies, St Cloud State University

    Attention and automaticity in social judgments from facial appearance: Cognitive and neural mechanisms

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    Recent evidence from behavioural and cognitive-neuroscience experiments has already yielded exciting discoveries into how we might code, process and perform judgments of facial social stimuli (indeed research into the latter provides a good vehicle for examining vision and object recognition in general). Nevertheless, the evidence regarding the role of top down control in face processing and the significance of the role of attentional capacity limits is contradictory or indeed absent in certain facial social trait judgments such as trustworthiness. In this thesis, I seek to present a portrayal of these roles, directed by load theory. Load theory suggests that perception has limited capacity but proceeds automatically on all stimuli until capacity is exhausted. Whether this process applies to arguably exceptional stimulus classes such as faces is contentious. Moreover, how this is related to social facial judgments such as trustworthiness, as compared to other evaluations such as threat and dominance judgments is unknown, as up until now, research on face-attention interactions has focused on directing visuospatial attention to emotional visual information rather than to facial trait judgments such as trustworthiness. In spite of this, the theory's predictions are clear; increasing the perceptual load of a task should consume capacity, thereby reducing processing of stimuli external to that task. Here I show that these predictions hold only for certain types of facial image evaluations but not for others. In a series of experiments that applied load theory, employing a combined visual search and face judgment task (where the level of attentional load in the search task was manipulated by varying the search set size of similar non-target letters), I find that under high perceptual load, observers become moderately less able to classify certain facial targets e.g. trustworthy ones as compared to dominant ones, even when these stimuli are fully expected and serve as targets. I also show the robustness of perceptual load effects by countering possible confounds and alternative explanations. Potential order effects are countered by reversing the order of the experiment, indicating that a possible attenuated short term memory imprint for the facial stimuli does not change the pattern of results previously experimentally demonstrated. Additionally, I find that high working memory load does not reduce social judgment evaluations under load, suggesting that perceptual biases during competitive interactions in visual processing are causative of the earlier demonstrated load effects. Following on from the modest but resilient results for trustworthiness modulation experimentally demonstrated here, the issue of bias for trustworthiness judgments is addressed in a signal detection paradigm (allowing bias to be discounted as a likely explanation of load effects). In the wake of the relatively robust results for trustworthiness perceptual load modulation, a new avenue for trustworthy judgments under attention is explored, investigating the possible role of dopamine in such evaluations in a clinical cohort of Parkinson's disease (PD) patients (as contrasted to age matched controls). PD has been linked with facial expression judgment impairment, although, this impairment could be subordinate to other cognitive processes enmeshed in facial evaluation, such as selective attention. Our results once again point to a pervasive role for perceptual load modulation of facial judgments, rather than a specific attentional deficit of PD. Finally, I explore the neurobiological correlates associated with facial social evaluations under perceptual load. In a neuroimaging study, I show neural responses to trustworthy facial images interact with attentional demands, demonstrating reduced activity under high perceptual load. I found high load only affects the facial components of trustworthiness (as compared to neutral faces) in cortical areas involved in social and facial processing (but not the facial signal components of untrustworthiness as compared to their neutral counterparts). The effects of load being specific to the trustworthy aspects of faces coheres with earlier presented behavioural results. As a final point, the demonstrated findings of negative-linear effects in the amygdala are consistent with prior research underlining the role of the amygdala in facial trustworthy judgments. This research presented here, although subtle in some experiments, provides convergent evidence that top-down cognitive and neural mechanisms are involved in influencing the degree to which facial visual judgments are processed. The results demonstrate the role of attentional modulation in facial social judgments and illuminate a possible role of perceptual load and attention in the facial automaticity debate. Both the type of facial judgment and category of facial valence are factors which determine the efficacy of perceptual load effects in facial evaluations

    The effects of internally and externally directed attention during motor skill execution and learning

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    Focusing attention onto the intended outcome or goal of a movement (an External focus of attention) has been shown to be more beneficial to the learning and performance of movements than focusing onto the components of the movement being carried out (an Internal focus of attention). In this thesis, four studies assessed the effects of attentional focusing strategies on the learning and execution of motor skills during different situations. Study 1 demonstrated that an internal focus of attention during a suprapostural pointing task resulted in degraded postural control as well as larger movements of the hand and arm. In Study 2 novices using an external focus were more accurate in a dart throwing task than those using an internal focus, but no different from a control condition. In Study 3 two experiments investigated the effects of attentional focuses on postural control at rest and whilst fatigued. Postural control was no better using external focus when compared to an internal focus at rest, but was better than baseline. When fatigued (localised and generalised), balance was significantly deteriorated using an external focus, but not when an internal focus was used. In two experiments during Study 4 novices carrying out a dart throwing task used different attentional focusing instructions during practice and later performance. During practice sessions in Experiment 4.1 and 4.2 accuracy was not affected by attentional focusing instructions. Using an external focus during performance resulted in significantly better accuracy than using an internal focus. In Experiment 4.2, novices who preferred an internal focus but used an external focus during performance performed less accurately than participants who preferred the external focus. Findings demonstrate that the benefits of an external focus of attention is evident in performance situations, whereas an internal focus may be beneficial whilst fatigued and is not detrimental during practice
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