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Gait analysis is the systematic study of human walking. Clinical gait analysis is the process by which quantitative information is collected for the assessment and decision-making of any gait disorder. Although observational gait analysis is the therapist's primary clinical tool for describing the quality of a patient's walking pattern, it can be very unreliable. Modern gait analysis is facilitated through the use of specialized equipment. Currently, accurate gait analysis requires dedicated laboratories with complex settings and highly skilled operators. Wearable locomotion tracking systems are available, but they are not sufficiently accurate for clinical gait analysis. At the same time, wireless healthcare is evolving. Particularly, ultra wideband (UWB) is a promising technology that has the potential for accurate ranging and positioning in dense multi-path environments. Moreover, impulse-radio UWB (IR-UWB) is suitable for low-power and low-cost implementation, which makes it an attractive candidate for wearable, low-cost, and battery-powered health monitoring systems. The goal of this research is to propose and investigate a full-body wireless wearable human locomotion tracking system using UWB radios. Ultimately, the proposed system should be capable of distinguishing between normal and abnormal gait, making it suitable for accurate clinical gait analysis. / Ph. D.

Doctor of Philosophy / Department of Electrical and Computer Engineering / William B. Kuhn / Balasubramaniam Natarajan / Wireless body area networks (WBANs) are an important part of the developing internet of things (IOT). NASA currently uses space suits with wired sensors to collect limited biomedical data. Continuous monitoring and collecting more extensive body vital signs is important to assess astronaut health. This dissertation investigates wireless biomedical sensor systems that can be easily incorporated into future space suits to enable real time astronaut health monitoring. The focus of the work is on the radio-wave channel and associated antennas. We show that the space suit forms a unique propagation environment where the outer layers of the suit’s thermal micrometeoroid garment are largely radio opaque. This environment can be modeled as a coaxial one in which the body itself plays the role of the coax center conductor while the space suit shielding materials play the role of the outer shield. This model is then validated through simulations and experiments. Selecting the best frequency of operation is a complex mixture of requirements, including frequency allocations, attenuation in propagation, and antenna size. We investigate the propagation characteristics for various frequency bands from 315 MHz to 5.2 GHz. Signal attenuation is analyzed as a function of frequency for various communication pathways through 3D simulations and laboratory experiments. Small-scale radio channel results indicate that using lower frequency results in minimal path loss. On the other hand, measurements conducted on a full-scale model suggest that 433 MHz and 2400 MHz yield acceptable path loss values. Propagation between the left wrist and left ankle yielded the worst overall path loss, but signals were still above –100 dBm in raw measurements for a 0dBm transmission indicating that the intra-suit environment is conducive to wireless propagation. Our findings suggest that the UHF bands are best candidate bands since there is interplay between the body conductivity favoring lower frequencies, and the difficulty of coupling RF energy into and out of the channel using suitably sized antennas favoring higher frequencies. Finally, a new self-shielded folded bow-tie antenna is proposed that can be a promising choice for the general area of WBAN technologies as well as potential new space suit environments.

Les réseaux à l'origine métropolitains, ont connu une tendance à rétrécir pour aujourd'hui se concentrer autour de l'être humain. Avec des équipements de plus en plus miniatures et les utilisateurs désireux de disposer en permanence des services qui leur sont accessibles à domicile, le réseau est envisagé plus petit, plus proche du corps. On assiste alors à l'émergence du réseau corporel, le Body Area Network (BAN), qui est constitué d'éléments situés sur le corps, à l'intérieur ou encore à une courte distance. Ce réseau à portée du corps génère de nouvelles problématiques, notamment celles de la puissance rayonnée par les équipements, leur taille, leur poids...Les applications et usages envisagés pour un tel réseau sont variés et couvrent plusieurs domaines d'activités, en l'occurrence le secteur du médical, du sport, et le multimédia. Ce réseau doit donc reposer sur une couche physique qui s'adapte aux contraintes de ces diverses applications, tout en favorisant des équipements de faible taille, faible complexité et de forte autonomie. La technologie Ultra Large Bande impulsionnelle (UWB-IR) est porteuse de nombreuses promesses pour satisfaire en partie les besoins des réseaux BAN, car autorisant des débits aussi bien réduits qu'élevés, et les architectures d'émission et réception utilisables pour cette technologie rendent possibles des équipements à faible complexité et faible coût, et dont la consommation énergétique est réduite.Ce travail de thèse a débuté alors qu'un processus de normalisation sur les BAN était en cours. L'objectif des travaux menés était de pouvoir contribuer en partie à ce processus de normalisation par la proposition d'une couche physique basée sur la radio impulsionnelle UWB (UWB-IR). Ainsi notre étude a porté sur le paramétrage de cette couche physique à partir de l'analyse des contraintes et requis techniques d'un réseau BAN. Les performances de cette couche physique ont ensuite été évaluées dans un contexte de canal UWB BAN et suivant le type d'architecture en réception, en particulier pour le récepteur non-cohérent. Enfin, une attention a été apportée sur la robustesse de la liaison en présence d'interférences bande étroite. Dans l'ensemble, ce travail a permis d'étudier et d'évaluer la pertinence d'une couche physique UWB-IR dans le contexte du réseau BAN / Absence de résumé en anglais

This research addresses the need for increased interoperability between the varied access control systems in use today, and for a secure means of providing access to remote physical devices over untrusted networks. The Universal Physical Access Control System (UPACS) is an encryption-enabled security protocol that provides a standard customizable device control mechanism that can be used to control the behavior of a wide variety of physical devices, and provide users the ability to securely access those physical devices over untrusted networks. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

The presented work considers a CDMA-based Wireless Body Area Network (WBAN) where multiple biosensors communicate simultaneously to a central node in an asynchronous fashion. The asynchronous nature of the WBAN introduces Multiple Access Interference (MAI). To combat this problem, presented is a methodology that uses a set of cyclically orthogonal spreading codes extracted from the Walsh-Hadamard matrix. When using the Cyclic Orthogonal Walsh-Hadamard Codes (COWHC) as spreading codes in the CDMA-based WBAN, the cyclic orthogonality property helps mitigate MAI amongst the on-body sensors. Presented is an ideal communication system that is most effective at mitigating MAI in proactive WBANs. The work illustrates the system optimality and effectiveness at mitigating MAI by studying the sensitivity to packet-loss through simulating the link Bit Error Rate (BER) performance. It is shown that the proposed design with COWHC, a Rayleigh flat-fading channel, BPSK modulation and a conventional receiver produce optimum MAI mitigation.

The presented work considers a CDMA-based Wireless Body Area Network (WBAN) where multiple biosensors communicate simultaneously to a central node in an asynchronous fashion. The asynchronous nature of the WBAN introduces Multiple Access Interference (MAI). To combat this problem, presented is a methodology that uses a set of cyclically orthogonal spreading codes extracted from the Walsh-Hadamard matrix. When using the Cyclic Orthogonal Walsh-Hadamard Codes (COWHC) as spreading codes in the CDMA-based WBAN, the cyclic orthogonality property helps mitigate MAI amongst the on-body sensors. Presented is an ideal communication system that is most effective at mitigating MAI in proactive WBANs. The work illustrates the system optimality and effectiveness at mitigating MAI by studying the sensitivity to packet-loss through simulating the link Bit Error Rate (BER) performance. It is shown that the proposed design with COWHC, a Rayleigh flat-fading channel, BPSK modulation and a conventional receiver produce optimum MAI mitigation.

Short range wireless data communication networks that are used for sport and health care are sometimes called Wireless Body Area Networks (WBANs) and they are located more or less on a person. Sole Integrated Gait Sensor (SIGS) is a research project in WBAN, where wireless pressure sensors are placed like soles in the shoes of persons with different kinds of deceases. The sensors can measure the pressure of the foot relative to the shoe i.e. the load of the two legs is measured. This information can be useful e.g. to not over or under load a leg after joint replacement or as a bio feedback system to help e.g. post stroke patients to avoid falling. The SIGS uses the ANT Protocol and radio specification. ANT uses the 2.4 GHz ISM band and TDMA is used to share a single frequency. The scheduling of time slots is adaptive isochronous co-existence i.e. the scheduling is not static and each transmitter sends periodically but checks for interference with other traffic on the radio channel. In this unidirectional system sole sensors are masters (transmitters) and the WBAN server is the slave in ANT sense. The message rate is chosen as 8 Hz which is suitable for low power consumption. Hence in the SIGS system, it is necessary to synchronize the left and the right foot sensors because of low message rate. In our thesis, we found a method and developed a prototype to receive the time synchronized data in WBAN server from ANT wireless sensor nodes in SIGS system. For this thesis work, a hardware prototype design was developed. The USB and USART communication protocols were also implemented in the hardware prototype. The suitable method for time synchronization was implemented on the hardware prototype. The implemented method receives the sensor data, checks for the correct stream of data; add timestamp to the sensor data and transmit the data to the Linux WBAN server. The time slots allocation in the ANT protocol was found. Alternative solution for the time synchronization in ANT protocol was also provided. The whole SIGS system was tested for its full functionality. The experiments and analysis which we performed were successful and the results obtained provided good time synchronization protocol for ANT low power wireless sensor network and for Wireless Bio-feedback system.

Αντικείμενο της διπλωματικής εργασίας είναι η μελέτη της συμπεριφοράς των WBAN (Wireless Body Area Networks) σαν μέρος του συστήματος παρακολούθησης υγείας ασύρματης τηλεϊατρικής. Αρχικά γίνεται σύντομη αναφορά στον τρόπο χρήσης των WBAN για την πραγματοποίηση της ιδέας της mHealth (mobile health) καθώς και σε ενδεικτικά ερευνητικά προγράμματα της Ευρωπαϊκής Ένωσης που περιλαμβάνουν χρήση της τεχνολογίας WBAN και της τεχνολογίας ασύρματων εμφυτεύσιμων αισθητήρων για εφαρμογές ιατρικής περίθαλψης, ενώ στη συνέχεια γίνεται περιγραφή της αρχιτεκτονικής του συστήματος ασύρματης τηλεϊατρικής. Έπειτα, περιγράφεται η αρχιτεκτονική των δύο βασικότερων πρωτοκόλλων επικοινωνίας για ασύρματους κόμβους αισθητήρων, Bluetooth Low Energy και ZigBee/IEEE 801.15.4 και αναλύεται το επίπεδο εφαρμογής του πρωτοκόλλου ZigBee. Τέλος, περιγράφεται η αρχιτεκτονική του ασύρματου κόμβου αισθητήρων και παρουσιάζονται και περιγράφονται οι τυπικές συσκευές που χρησιμοποιούνται σε ένα WBAN ιατρικής περίθαλψης. / The purpose of my diploma thesis was the study of WBAN (Wireless Body Area Networks) as part of the wireless telemedicine health-monitoring system. I focused on the architecture of the integrated telemedicine system, the architecture of the two main communication protocols used in WBANs, Bluetooth LE and ZigBee/IEEE 801.15.4, and the specification of the ZigBee Application Layer. Finally, I described the typical architecture of the wireless sensor node and the typical devices that are used in a health WBAN.

Récemment la bande 60 GHz a été mise en avant pour le développement des réseaux de communication sans fil centrés sur le corps humain. Cet intérêt de la bande 60 GHz pour les applications BAN (Body Area Network) s'explique par les avantages clefs qu'elle procure par rapport aux bandes de fréquence plus basses (possibilité de débits de données supérieurs à 7 Gbit/s, réduction des interférences avec les réseaux voisin, compacité des dispositifs, etc). Le nombre d'application de communication BAN est amené à croître dans les années à venir avec le déploiement de la 5ème génération de réseaux de télécommunications mobiles. Afin de protéger efficacement les utilisateurs des expositions générées par ces applications BAN à 60 GHz, il est nécessaire de se pencher sur les problématiques de réduction du couplage corps/antennes, mais également sur l'évaluation et la quantification du niveau d'exposition du corps à 60 GHz. Pour cela, les travaux de thèse ont été organisés suivant trois axes de recherche : le premier consiste à mettre en évidence et à quantifier l'impact de certains choix de conception en matière d'antennes sur le couplage avec le corps humain ; le second porte sur les outils et les méthodes utilisés pour estimer l'impact thermique d'une exposition électromagnétique 60 GHz sur le fantôme équivalent de la peau ; et le troisième propose une nouvelle approche à la fois dosimétrique et thermique pour évaluer et analyser le couplage corps/antennes en bande millimétrique. / The 60-GHz frequency band has been identified recently as attractive for body centric wireless communication development. Indeed, this band has several key advantages compared to lower frequency bands as high data rates above 7 Gbit/s, low risks of interference with neighboring wireless networks and compact devices. With the development of the future 5th generation of mobile networks in the millimeter-wave band, the number of BAN applications at 60 GHz should increase. To avoid health effects and protect user against an electromagnetic exposure of BAN devices at 60 GHz, the reduction of the coupling between human body and antennas, as well as the evaluation and quantification of exposure are main research aspect of the thesis. The main thesis contributions are divided in three parts: a quantification of antenna design effects on the interactions between human body and antennas; a study of tools and methods used to assess thermal effects due to 60 GHz exposure on a skin-equivalent phantom; and a new dosimetric and thermal approach to evaluate interaction between human body and BAN antennas at 60 GHz.