Les secouristes, par la nature et le cadre de leurs missions, interviennent en environnement à risque et mettent parfois leur santé en danger. Afin de minimiser ce risque, de nouveaux Equipements de Protection Individuelle (veste, tee-shirt et bottes) ont été conçus par un consortium européen de 23 partenaires réunis autour du programme de recherche ProeTEX. Ces travaux de thèse s’inscrivent dans le cadre de ce projet et ont pour objectif de développer un système de monitoring ambulatoire des paramètres thermiques du pompier qui sera intégré aux vêtements intelligents destinés aux secouristes. L’intérêt de cette intégration est le prépositionnement des capteurs afin de réduire le temps de préparation du secouriste. La surveillance s’opère à deux niveaux : l’interface Homme-environnement et le corps. Afin d’évaluer le risque thermique encouru, les paramètres faisant l’objet d’un suivi sont : la température interne, mesurée depuis le tee-shirt, et la température externe et le flux thermique, mesurés dans la veste. Ces paramètres permettent d’apprécier la contrainte thermique imposée par l’environnement et l’état de santé du pompier. Deux méthodes de mesure des paramètres thermiques dans la veste ont été développées. Le projet a abouti au développement de prototypes fonctionnels dont les performances ont été attestées en centre de validation. Des tests ont été conduits en laboratoire et en conditions extrêmes sur le terrain à la Brigade de Sapeurs-Pompier de Paris et au « International Firefighting, Survival and Rescue at Sea Training Center » de Pavie, Italie, pour démontrer la fonctionnalité des EPI en conditions réelles. / Rescuers, within the framework of their missions, operate in hazardous condition and sometimes put their health at risk. To minimize this risk, new personal protective equipment (jacket, t-shirt and boots) were designed by a 23 European partners’ consortium within the research program ProeTEX. This thesis is part of this project and aims to develop an ambulatory monitoring system for firefighters’ thermal parameters; It will be integrated into smart clothes for rescuers. Monitoring is taking place at two levels: Human-environment interface and body. To evaluate the thermal hazard involved, the parameters being monitored are: internal temperature, measured from the tee-shirt and external temperature and heat flux, in the jacket. These parameters are used to assess heat stress imposed by the environment and the health status of the fire-fighter. Two methods of measurement of thermal parameters in the jacket were developed. The project resulted in the development of functional prototypes whose performances have been vouched in validation center. Tests took place in the laboratory and during field trails in extreme conditions.

Emotions are an integral part of the human experience and their interpretation can provide valuable but also misleading clues about oneself and other people’s state of mind. Negative emotional states can be perceived as uncomfortable and – when experienced chronically – can develop into anxiety and mood disorders. The more pervasive these disorders the more severely they affect and disable a person’s everyday functioning and often their sleep as well. According to Lang and colleagues (1998), emotions may be expressed verbally, behaviorally, and physiologically, i.e., emotions can be reported, observed, and objectively measured. Each measurement approach provides important, unique, and often conflicting information that can be used in the assessment and treatment evaluation of psychological disorders affecting the emotions. Autonomic measures have been used to indicate the physiological components of emotions, such as those along the worry-anxiety-fear-panic spectrum. Worry has been shown to suppress cardiac responses to imaginal feared material (see Borkovec, Alcaine, & Behar, 2004) and reduce autonomic variability (Hoehn-Saric, McLeod, Funderburk, & Kowalski, 2004; Hoehn-Saric, McLeod, & Zimmerli, 1989). Results for panic and anticipatory anxiety are less conclusive but theoretically these states should go along with increased autonomic arousal. Abnormal autonomic arousal might also be present during sleep as both panic disorder and worrying have been associated with sleeping difficulties. However, most empirical research has been confined to the laboratory where high internal validity is achieved at the cost of poor ecological validity. Thus, the purpose of this doctoral dissertation is to extend and validate laboratory findings on worry, anticipatory anxiety, and panic using ambulatory monitoring. Twenty-four hour monitoring not only can give valuable insights into a person’s daytime emotional experience but also allows observing how these emotions might affect their sleep in their natural environment. In the following chapter, the reader will be introduced to a conceptual framework that ties together worry, anxiety, fear, and panic, and related anxiety disorders (section 2.1), to autonomic arousal and electrodermal and cardiac arousal in particular (section 2.2), to sleep and its relation to autonomic arousal and anxiety disorders (section 2.3), and to ambulatory monitoring (section 2.4). After illustrating the aims of this thesis (chapter 3), chapters 4 to 6 present the results of three empirical studies conducted as part of this doctoral research. The first study deals solely with electrodermal monitoring and how it is affected by confounding variables in an ambulatory context (chapter 4). The next study then seeks to investigate the relationship between electrodermal arousal and anticipatory anxiety and panic in a sample of panic disorder patients and healthy controls. The last study focuses primarily on the effect of trait and state worry on subjective and objective sleep and electrodermal and cardiac arousal in a group of high and low worriers. Chapters 7 to 9 summarize and integrate the findings from these three empirical studies, discuss methodological limitations, and provide an outlook into future research.

Les problèmes liés à l'équilibre sont diagnostiqués à l'aide de systèmes de cartographies des pressions plantaires ou de plateformes de force mesurant le déplacement du centre de pressions. Ces systèmes professionnels sont restreints à une utilisation en milieu médical, et on constate qu'aucun dispositif de surveillance de l'équilibre ne donne entière satisfaction en termes de mobilité et d'acceptabilité. Dans le contexte de la télémédecine et de l'e-santé, notre objectif a consisté à développer des outils pour la surveillance ambulatoire de l'équilibre postural, et contribuer à la compréhension du contrôle de l'équilibre. Nous avons d'abord entrepris une étude théorique de la faisabilité de la mesure des pressions plantaires et du déplacement dynamique du centre de pression, à partir d'un nombre très réduit de capteurs. Nous avons proposé pour cela un modèle mécanique simplifié du pied, ainsi que les hypothèses spécifiques à ces applications. Le modèle décrit la relation physique entre la posture du pied et la répartition des pressions plantaires suivant ses caractéristiques biomécaniques. Sur la base d'un prototype de semelle instrumentée à 3 capteurs uniquement, nous avons vérifié expérimentalement la capacité du système et des méthodes à générer le stabilogramme et les cartographies de pressions plantaires. Ceux-ci ont été comparés à un système matriciel de référence, et caractérisés en termes d'incertitude dans le cas du pied normal en position debout et durant la marche. Les stabilogrammes ainsi mesurés peuvent être analysés pour caractériser la signature de l'équilibre. Nous proposons un modèle spécifique à trois dimensions, décrivant la dynamique de l'équilibre et permettant d'identifier, par simulation, les principaux paramètres physiologiques qui assurent le maintien de l'équilibre postural. / Problems of balance are often diagnosed thanks to plantar pressure cartography systems or forces platform that measure the center of pressure displacement. These professional systems are restricted in use to medical environments, and until now, the balance monitoring systems do not offer complete satisfaction in terms of mobility and acceptability. In order to overcome these limitation and in the context of telemedicine and e-health, we aimed to develop tools for ambulatory monitoring of postural equilibrium and to understand the balance control. We have first undertaken a theoretical study on the feasibility of measuring plantar pressure and dynamic displacement of the center of pressure, from a very small number of sensors. For these applications, we have proposed a simplified mechanical foot model, as well as related assumptions. The model describes the physical relationship between foot posture and distribution of plantar pressures following its biomechanical characteristics. Based on a prototype of an instrumented insole with only 3 sensors, we have verified experimentally the ability of the system and the methods to generate both the stabilogram and the plantar pressure maps. Comparison is made with a matrix reference system, and characterization in terms of uncertainty in the case of normal foot in standing position and during walking is detailed. The measured stabilogram can be analyzed to characterize the signature of balance. We have also proposed a specific three-dimensional model describing the dynamics of balance. Based on simulation, it leads to identify the main physiological parameters related to balance control.

Emotions are an integral part of the human experience and their interpretation can provide valuable but also misleading clues about oneself and other people’s state of mind. Negative emotional states can be perceived as uncomfortable and – when experienced chronically – can develop into anxiety and mood disorders. The more pervasive these disorders the more severely they affect and disable a person’s everyday functioning and often their sleep as well. According to Lang and colleagues (1998), emotions may be expressed verbally, behaviorally, and physiologically, i.e., emotions can be reported, observed, and objectively measured. Each measurement approach provides important, unique, and often conflicting information that can be used in the assessment and treatment evaluation of psychological disorders affecting the emotions. Autonomic measures have been used to indicate the physiological components of emotions, such as those along the worry-anxiety-fear-panic spectrum. Worry has been shown to suppress cardiac responses to imaginal feared material (see Borkovec, Alcaine, & Behar, 2004) and reduce autonomic variability (Hoehn-Saric, McLeod, Funderburk, & Kowalski, 2004; Hoehn-Saric, McLeod, & Zimmerli, 1989). Results for panic and anticipatory anxiety are less conclusive but theoretically these states should go along with increased autonomic arousal. Abnormal autonomic arousal might also be present during sleep as both panic disorder and worrying have been associated with sleeping difficulties. However, most empirical research has been confined to the laboratory where high internal validity is achieved at the cost of poor ecological validity. Thus, the purpose of this doctoral dissertation is to extend and validate laboratory findings on worry, anticipatory anxiety, and panic using ambulatory monitoring. Twenty-four hour monitoring not only can give valuable insights into a person’s daytime emotional experience but also allows observing how these emotions might affect their sleep in their natural environment. In the following chapter, the reader will be introduced to a conceptual framework that ties together worry, anxiety, fear, and panic, and related anxiety disorders (section 2.1), to autonomic arousal and electrodermal and cardiac arousal in particular (section 2.2), to sleep and its relation to autonomic arousal and anxiety disorders (section 2.3), and to ambulatory monitoring (section 2.4). After illustrating the aims of this thesis (chapter 3), chapters 4 to 6 present the results of three empirical studies conducted as part of this doctoral research. The first study deals solely with electrodermal monitoring and how it is affected by confounding variables in an ambulatory context (chapter 4). The next study then seeks to investigate the relationship between electrodermal arousal and anticipatory anxiety and panic in a sample of panic disorder patients and healthy controls. The last study focuses primarily on the effect of trait and state worry on subjective and objective sleep and electrodermal and cardiac arousal in a group of high and low worriers. Chapters 7 to 9 summarize and integrate the findings from these three empirical studies, discuss methodological limitations, and provide an outlook into future research.

Global rise in life expectancy has resulted in an increased demand for affordable healthcare and monitoring services. The advent of miniature and low–power sensor technologies coupled with the emergence of the Internet–of–Things has paved the way towards affordable health monitoring tools in wearable platforms. However, ensuring power–efficient operation, data accuracy and user comfort are critical for such wearable systems. This thesis focuses on the development of accurate and computationally efficient algorithms and low–cost, unobtrusive devices with potential predictive capability for monitoring mobility and cardiac health in a wearable platform. A three–stage complementary filter–based approach is developed to realize a computationally efficient method to estimate sensor orientation in real–time. A gradient descent–based approach is used to estimate the gyroscope integration drift, which is subsequently subtracted from the integrated gyroscope data to get the sensor orientation. This predominantly gyroscope–based orientation estimation approach is least affected by external acceleration and magnetic disturbances. A two–stage complementary filter–based efficient sensor fusion algorithm is developed for real–time monitoring of lower–limb joints that estimates the IMU inclinations in the first stage and uses a gradient descent–based approach in the second stage to estimate the joint angles. The proposed method estimates joint angles primarily from the gyroscope measurements without incorporating the magnetic field measurement, rendering the estimated angles least affected by any external acceleration and insensitive to magnetic disturbances. An IMU–based simple, low–cost and computationally efficient gait–analyzer is developed to track the course of an individual's gait health in a continuous fashion. Continuous monitoring of gait patterns can potentially enable detecting musculoskeletal or neurodegenerative diseases at the early onset. The proposed gait analyzer identifies an anomalous gait with moderate to high accuracy by evaluating the gait features with respect to the baseline clusters corresponding to an individual’s healthy peer group. The adoption of a computationally efficient signal analysis technique renders the analyzer suitable for systems with limited processing capabilities. A flexible dry capacitive electrode and a wireless ECG monitoring system with automatic anomaly detection capability are developed. The flexible capacitive electrode reduces motion artifacts and enables sensing bio–potential over a dielectric material such as cotton cloth. The virtual ground of the electrode allows for obtaining single–lead ECG using two electrodes only. ECG measurements obtained over different types of textile materials and in presence of body movements show comparable performance to other reported ECG monitoring systems. An algorithm is developed separately as a potential extension of the software to realize automatic identification of Atrial Fibrillation from short single–lead ECGs. The association between human gait and cardiac activities is studied. The gait is measured using wearable IMUs and the cardiac activity is measured with a single–lead handheld ECG monitor. Some key cardiac parameters, such as heart rate and heart rate variability and physical parameters, such as age and BMI show good association with gait asymmetry and gait variation. These associations between gait and heart can be useful in realizing low–cost in–home personal monitoring tool for early detecting CVD–related changes in gait features before the CVD symptoms are manifested. / Thesis / Doctor of Philosophy (PhD) / Wearable health monitoring systems can be a viable solution to meet the increased demand for affordable healthcare and monitoring services. However, such systems need to be energy–efficient, accurate and ergonomic to enable long–term monitoring of health reliably while preserving user comfort. In this thesis, we develop efficient algorithms to obtain real–time estimates of on–body sensors' orientation, gait parameters such as stride length, and gait velocity and lower–limb joint angles. Furthermore, we develop a simple, low–cost and computationally efficient gait–analyzer using miniature and low–power inertial motion units to track the health of human gait in a continuous fashion. In addition, we design flexible, dry capacitive electrodes and use them to develop a portable single–lead electrocardiogram (ECG) device. The flexible design ensures better conformity of the electrode to the skin, resulting in better signal quality. The capacitive nature allows for obtaining ECG signals over insulating materials such as cloth, thereby potentially enabling a comfortable means of long–term cardiac health monitoring at home. Besides, we implement an automatic anomaly detection algorithm that detects Atrial Fibrillation with good accuracy from short single–lead ECGs. Finally, we investigate the association between gait and cardiac activities. We observe that some important cardiac signs, such as heart rate and heart rate variability and physical parameters, such as age and BMI show good association with gait asymmetry and gait variation.