Les récents progrès technologiques ont permis la miniaturisation des capteurs de mouvement permettant ainsi leur intégration dans des micro-systèmes médicaux de manière à ce qu'ils soient aisément portables par les personnes. Dans cette thèse nous proposons des algorithmes de traitement de données permettant d’interpréter les mesures de capteurs accélérométriques et de les associer aux différentes activités. Notre approche est fondée sur l’observation que la séquence d’activités à détecter possède une structure forte de dépendance temporelle. Nous proposons un système de reconnaissance de l’activité reposant sur une modélisation des activités comme une chaîne de Markov. En outre, notre système s’appuie sur des méthodes de classification paramétriques et non paramétriques. La sortie douce des classifieurs permet de construire des mesures de confiance en les activités. Ces mesures sont injectées dans l’algorithme de Viterbi qui fournit la séquence d’activités finale. Nos algorithmes sont validés à partir d’une base de données comportant 48 sujets ayant chacun réalisé environ 90 minutes d’activités physiques variées. Par ailleurs, cette thèse vise à fournir des réponses pratiques aux problèmes posés par l’élaboration d’un système de reconnaissance de l’activité physique. En premier lieu, nous nous posons la question du placement optimal des capteurs sur le corps, et du nombre de capteurs nécessaires pour une estimation fiable de l’activité. Nous abordons le problème de la sélection des caractéristiques pertinentes pour les classifieurs. Enfin, un problème crucial est lié à l’estimation autodidacte et en ligne de l’orientation des capteurs sur le corps du sujet : il s’agit du problème de la calibration des capteurs. Pour terminer, nous fournissons une implémentation “temps-réel” du système proposé, et construisons une base de données en vie libre pour valider notre démonstrateur temps-réel. / Advances in technology have led to the miniaturization of motion sensors, facilitating their use in small comfortable wearable devices. Such devices are of great interest in the biomedical field especially for applications aimed at estimating the daily physical activity of people. In this thesis, we propose signal processing algorithms allowing better interpretation of sensors measures and thus their mapping to different activities. Our approach is based on that activities have strong temporal dependencies. We propose a recognition system that models the activity sequence by a Markov chain. Our system relies on parametric and non-parametric classification methods. The soft output of classifiers permits the construction of confidence measures in the activities. These measures are later used as input to a Viterbi algorithm that gives the final estimation of the activity sequence. We validate our algorithms using a database containing 48 subjects, each of whom having carried out activities for more than 90 minutes. Moreover, this thesis aims at providing practical answers to challenges concerning the development of an activity recognition system. First of all, we wonder about the optimal sensor placement on the body, and about the number of sensors needed for a reliable estimation of activities. We also approach the problem of selecting relevant features for classifiers. Another crucial issue concerns the estimation of the sensor’s orientation on the body : this involves the problem of sensor calibration. Finally, we provide a “real-time” implementation of our system, and collect a database under realistic conditions to validate our implemented real-time demostrator.

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 99-111). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

The concept of sleep disturbance is rather vague. Many people claim to suffer from sleep disturbance, but yet find it hard to describe exactly what they mean by the label in subjective terms. Sleep researchers have a similar problem, it is difficult to describe what is meant by sleep disturbance either in an objective or a subjective way, and harder still to relate sleep disturbance to sleepiness shown the following day.

Thesis (M.S. in Human Systems Integration)--Naval Postgraduate School, September 2009. / Thesis Advisor(s): Miller, Nita Lewis. "September 2009." Description based on title screen as viewed on 5 November 2009. Author(s) subject terms: Navy Standard Workweek (NSWW), Fatigue Avoidance Scheduling Tool (FAST), sleep, activity, Fatigue and Task Effectiveness Model (SAFTE), shiftwork, circadian rhythm, sleep, fatigue management, actigraphy, operational manning requirements. Includes bibliographical references (p. 87-89). Also available in print.

No description available.

Background: Sleep is commonly disrupted following pediatric concussion. Recently, post-concussion sleep quality has been identified as a potential factor that may influence recovery length. However, few studies have examined this relationship using objective sleep measures in a pediatric population. Nor, have any studies examined the trajectory of objective sleep parameters after pediatric concussion. Objectives: The purpose of this thesis is to: 1) Provide a review of current literature regarding pediatric concussion, healthy sleep quality, and sleep quality in the context of concussion and recovery from concussion; 2) Examine how objective sleep outcomes are affected and change post-concussion in children and adolescents; 3). Explore how post-concussion sleep quality parameters are related to length of recovery, quality of life (QOL), and depression symptomatology; and 4) Discusses the results from the two studies in the context of current literature and of each other. Methods: Sleep quality was inferred from the outcomes of five objective sleep parameters. Sleep parameters were measured using actigraphy in children and adolescents with concussion following return to school (RTA) and return to activity (RTA) protocols. Sleep data during the initial 4 weeks of recovery was assessed as an outcome, as a predictor of recovery length, and as a correlate of quality of life (QOL) and depression symptomatology Results: Most objective post-concussion sleep quality parameters were adversely affected by concussion but show trajectories indicating improvement throughout the initial 4 weeks of recovery. Sleep quality parameters were not associated with time to complete return to school or activity protocols. Sleep parameters were not strongly correlated with QOL or depression symptomatology outcomes. Conclusions: These results indicate that objective post-concussion sleep quality is impaired following concussion, but these outcomes do not appear to be associated with recovery, QOL or depression symptomatology. Other factors, or improvements in sleep quality may better explain recovery outcomes. / Thesis / Master of Science (MSc) / Children and adolescents are at risk for experiencing changes in sleep following concussion that result in poor sleep quality. Given the important role of sleep in maintaining our overall health, sleep likely plays a role in recovery. However, this relationship is poorly understood. The purpose of this dissertation is to identify how sleep changes following concussion and how these changes affect sleep quality and recovery. Study results reveal that the sleep parameters in the initial 4 weeks following concussion are significantly affected by concussion, suggesting that the sleep quality of children and adolescents is poorer than healthy youth. However, sleep quality does appear to improve with time. Further analyses found sleep quality does not appear to be related to recovery length or outcomes. Thus, the sleep quality of youth may be negatively impacted by concussion, but this may not directly influence recovery.

The amount of sleep per day among new Cadets at West Point during Cadet Basic Training (CBT) was investigated. Sleep was measured using actigraphy. The results indicated that new Cadets slept an average of approximately 340 minutes or 5 hours, 40 minutes per night. The results were compared with survey data to determine whether or not reported sleep prior to arrival at West Point matched measured sleep at CBT. The findings indicate that the study population is sleep-deprived during CBT. Additionally, the results show that, on average, New Cadets receive 2 hours, 6 minutes less sleep per night during CBT than before their arrival at West Point. The findings also indicate that sleep achieved was not due to the various comparison factors: Gender, Race, Company, Age, Recruited Athlete, and Morningness/Eveningness preference.

Approved for public release; distribution is unlimited / The Marine Aviation Weapons and Tactics Squadron One (MAWTS-1) command requested a sleep and performance study of the instructors and students of Weapons and Tactics Instructor (WTI) course 2- 16. Specifically, MAWTS-1 leadership wanted to know whether crew rest periods were being used for sleep and whether fatigue posed a risk to personnel during the course. This thesis expanded upon prior studies in military educational environments. The WTI 2-16 study collected sleep and performance data via wrist-worn actigraphy and psychomotor vigilance tests (PVT). Sleep duration and efficiency remained high throughout the course, but participation waned before the study ended. Both instructors and students appeared to receive adequate sleep of good quality (overall mean 7.4 hrs/night). There was little variability in the sleep patterns (i.e., WTI participants were abiding by the crew rest regulations). Compliance posed a significant challenge and limited the ability to correlate sleep to performance. We also measured self-reported fatigue and mood using standardized questionnaires. Results from subjective assessments showed a significant increase in self-reported fatigue as the course progressed. This thesis outlines a detailed methodology and lessons learned for follow-on studies of this type and recommends improvements to future studies. / Major, United States Marine Corps

Obstructive sleep apnoea (OSA) is a common disorder involving repeated cessations of breathing due to airway collapse, causing disruption of sleep cycles. The condition is under-diagnosed and the side effects are many and varied. Currently, the ‘gold standard’ diagnostic tool for OSA is a polysomnogram (PSG) which is carried out overnight in a hospital using multiple sensors. A PSG is expensive to set-up, run and analyse, and some subjects experience different sleep patterns due to the artificial conditions of the sleep laboratory. The aim of this thesis was to find a parsimonious and easy-to-collect set of signals (from the superset of signals recorded in sleep clinics) and other related information (such as demographics), and a set of automated methods that reliably determine which subjects are suitable for standard treatments, i.e. classify subjects requiring treatment (moderate OSA, severe OSA) from those not requiring treatment (normal, snorer, mild OSA), using a smartphone. Data were collected from 1354 subjects in the home using the Grey Flash polysomnographic recording device (Stowood Scientific Instruments, Oxford, UK). Analysis of the audio signal was initially performed using standard speech processing methods, where individual events were annotated and classified. The results achieved (accuracy (Ac) = 69.6%) using this approach were lower than those required for clinical acceptance. In all subsequent work in the thesis, subjects were classified from entire recordings rather than events. Multiscale entropy (MSE) was used to identify non-linear correlations in the audio data and quantify the irregularity of the data over many time scales. The inter-snore interval (ISI) was developed, motivated by clinical intuition. MSE and ISI were then applied to both actigraphy and photoplethysomgraphy (PPG) data, and different combinations of features were analysed. The features which displayed the highest predictive accuracy were derived from the PPG signal (Ac = 89.2%). This work demonstrated that, although audio- and actigraphy-based OSA screening is possible, to achieve clinically acceptable performance PPG remains an important key factor in diagnosis.

INTRODUÇÃO: A atividade física regular trás benefício à saúde, reduzindo a obesidade, morbidades e a mortalidade e, em pacientes asmáticos, a atividade física melhora os sintomas da doença. Apesar disso, ainda existe divergência na literatura se crianças asmáticas são fisicamente ativas, e isto parece depender do método empregado, da gravidade da doença e do controle clínico. OBJETIVO: Comparamos a atividade física de vida diária (AFVD) entre crianças com diferentes gravidades da asma e identificamos fatores que possam dificultar a realização das AFVD. MÉTODO: Estudo transversal com 121 crianças, sendo 79 asmáticas das quais (32 asma persistente leve, 24 asma persistente moderada, 23 asma persistente grave) e 42 controles, de ambos os sexos, com idade entre 7 a 12 anos. As crianças asmática estavam em tratamento médico há, no mínimo, 6 meses e com a doença controlada. O nível de AFVD foi monitorado com um acelerômetro durante 6 dias (4 dias da semana e 2 de final de semana). A função pulmonar e as barreiras que dificultam a realização da AFVD também foram avaliadas. RESULTADOS: Os nossos resultados mostraram que o número total de passos, e as atividades realizadas em intensidade moderada foram similares entre as crianças com as diferentes gravidades da asma. O percentual de crianças asmáticas fisicamente ativas foi similar quando comparado com as crianças sem asma (respectivamente, 51,9% vs. 50%; p>0,05). Não foi observada diferença nos parâmetros funcionais da função pulmonar (obstrução fixa, resposta ao broncodilatador e variabilidade do VEF1) entre as crianças asmáticas fisicamente ativas e as sedentárias (p>0,05). Porém, foi observado um maior percentual de crianças com sobrepeso ou obesidade entre os asmáticos sedentários quando comparado às crianças fisicamente ativas (respectivamente, 24,1% vs. 11,1%; p<0,05). As barreiras ambientais foram as mais relatadas pelas crianças com e sem asma (p>0,05), porém este fator foi relatado em maior proporção pelas crianças asmáticas sedentárias quando comparado àquelas fisicamente ativas (respectivamente, 34,2% vs. 14,6%; p<0,05). CONCLUSÕES: As crianças asmáticas com a doença controlada tiveram o mesmo nível de AFVD entre as diferentes gravidades da doença e que seus pares sem asma. A gravidade da doença, fatores ligados à função pulmonar e a percepção da doença como barreira para atividade física pareceu não estar associadas ao sedentarismo. As barreiras ambientais foram as mais relatadas pelas crianças com e sem asma, porém, nas crianças asmáticas sedentárias essas barreiras pareceram ser ainda mais relevantes / BACKGROUND: Regular physical activity promotes health benefits by reducing obesity, morbidity and mortality, and who has asthma, physical activity improves the symptoms of disease. Nevertheless, there is disagreement in the literature whether asthmatic children are physically active, and this seems to depend on the method used, severity of disease and clinical control. OBJECTIVE: We compared Daily Physical Activity (DPA) among children of different severity levels of asthma and we have identified factors that may hinder DPA. METHOD: Cross-Sectional study with 121 children, 79 with asthma (32 mild persistent asthma, 24 moderate persistent asthma, 23 severe persistent asthma) and 42 children without asthma, of both sexes, aged between of 7 and 12 years. The asthmatic children were under medical treatment for at least 6 months and the disease controlled. DPA was monitored with an accelerometer for 6 days (4 weekdays and 2 weekends). Pulmonary function and barriers that hinder DPA were also assessed. RESULTS: Our results showed that the total number of steps, and the activities performed at moderate intensity were similar between children with different severities of asthma. The percentage of physically active children with asthma was similar when compared with children without asthma (respectively, 51,9% vs. 50%; p>0,05). There was no difference in respiratory function parameters (fixed obstruction, bronchodilator response and variability of FEV1) among the asthmatic children physically active and sedentary (p> 0.05). However, we found that sedentary asthmatic children were more overweight or obese than physically active asthmatic children (respectively, 24,1% vs. 11,1%; p<0,05). The environmental barriers were the most frequently reported by children with and without asthma (p> 0,05), but this factor was reported in a higher proportion by sedentary asthmatic children compared to those physically active (respectively, 34,2% vs. 14,6%; p<0,05). CONCLUSIONS: Clinically controlled asthmatic children had the same level of DPA between different severities of asthma and their peers without asthma. The severity of disease, factors related to lung function and perception of disease as a barrier to physical activity did not seem be associated with sedentary lifestyle. The environmental barriers were the most frequently reported by children with and without asthma, however in sedentary asthmatic children these barriers seemed to be even more relevant