Contactless breathing estimation using radars has been explored since the 1960s and an accurate system with the ability to continuously monitor the health of non-critical patients without obstructing their day to day lives could significantly improve their well being. The current state of the art in this area does not have the accuracy required to work in a real-world environment and many of the existing methods have been tested only under very controlled situations. Low performance of breathing estimation algorithms under different scenarios inspired us to improve breathing estimation algorithms and develop a system for automated analysis of large number of algorithms against data from the reference sensors. A novel accurate breathing rate estimation method and a system to use multiple algorithms on the same set of data in real-time and identify the best performing algorithm dynamically to report breathing rate have been proposed in this thesis. In addition, automated data-collection and processing frameworks were developed to collect a large amount of data and process them and generate reports automatically. The proposed system has been tested under multiple test-cases involving multiple subjects and the accuracy of both new and existing algorithms have been evaluated by comparing the results with reference data collected using a respiration belt. The mean absolute error rate of breathing rate estimation after conducting experiments for a total of 9 subjects was found to be 0.79 breaths per minute for the novel CEEMD based method presented in this thesis. The mean absolute error rate after applying the scoring algorithm to select the best performing algorithm is 0.78 breaths/minute.

The research presented in this dissertation is the result of our laboratory's effort to develop a microfluidic platform to interrogate, manipulate, isolate, and enrich rare mammalian cells dispersed within heterogeneous populations. Relevant examples of these target cells are stem cells within a differentiated population, circulating tumor cells (CTCs) in the blood stream, and tumor initiating cells (TICs) in a population of benign cancer cells. The ability to isolate any of these rare cells types with high efficiency will directly lead to advances in tissue engineering, cancer detection, and individualized medicine. This work lead directly to the development of a new cell manipulation technique, termed contactless dielectrophoresis (cDEP). In this technique, cells are isolated from direct contact with metal electrodes by employing fluid electrode channels filled with a highly conductive media. Thin insulating barriers, approximately 20 μ­m, serve to isolate the fluid electrode channels from the low conductivity sample buffer. The insulating barriers in a fluid-electrical system create a number of unique and interesting challenges from an electrical engineering standpoint. Primarily, they block the flow of DC currents and create a non-constant frequency response which can confound experimental results attempting to characterize the electrical characteristics of cells. Due to these, and other, considerations, the use of high-voltage high-frequency signals are necessary to successfully manipulate cells. The effect of these high frequency fields on cells are studied and applied to microfluidic and tissue level applications. In later chapters, theoretical and experimental results show how high frequency and pulsed electric fields can ablate cells and tissue. Understanding the parameters necessary to electroporate cells aids in the development of cDEP devices where this phenomenon is undesirable and gives insight towards the development of new cancer ablation therapies where targeted cell death is sought after. This work shows that there exists a finite frequency spectrum over which cDEP devices can operate in which cells are minimally affected by the induced electric fields. Finally, lessons learned in the course of the development of cDEP were adapted and applied towards cancer ablation therapies where electroporation are favorable. It was found that bursts of high frequency pulsed electric fields can successfully kill cells and ablate tissue volumes through a process termed High Frequency Irreversible Electroporation (H-FIRE). This technique is advantageous as these waveforms mitigate or eliminate muscle contractions associated with traditional IRE technologies. Similarly, the use of fluid electrodes in cDEP inspired the use of an organs vascular system as the conductive pathway to deliver pulses. This novel approach allows for the ablation of large volumes of tissue without the use of puncturing electrodes. These techniques are currently undergoing evaluation in tissue engineering applications and pre-clinical evaluation in veterinary patients. / Ph. D.

Micro-assembly is of crucial importance in industry nowadays. Nevertheless, currently applied processes require improvements. Indeed, when dealing with the assembly of submillimetric components, usually neglected surface forces disturb the manipulation task. They are responsible for the component sticking to the gripper, because of downscaling laws. A promising strategy to tackle adhesion consists in working without contact. The present dissertation is focused on contactless handling with acoustic levitation. The advantages of contactless handling, the physical principles suitable for levitation and their applications are detailed. The opportunity for new handling strategies are shown. Acoustic levitation appears as the most fitted principle for micro-assembly. The elements to model acoustic forces are analysed and performances of existing modellings are assessed. A general numerical model of acoustic forces is implemented and theoretically validated with literature benchmarks. A fully automated modular levitator prototype is designed and used to experimentally validate the implemented numerical model. Specific instrumentations and protocols are developed for the acoustic force measurements. The numerical model is finally applied to the real levitator. Modelling results are used to support experimental observations: the optimisation of the levitator resonance, the influence of the reflector shape, the dynamical study of the component oscillations, the stability with lateral centring forces and rotation torques, the component insertion and extraction from the levitator, the effect of pressure harmonics on the acoustic forces, and the manipulation of non spherical components. Acoustic forces are experimentally measured and a very good agreement with the modellings is obtained. Consequently, the implemented simulation tool can successfully be applied to a complex manipulation task with a component of any shape in a real levitator.

The aim of this thesis is to provide a comprehensive view on the issue of contactless payments in various forms, as well as capture the actual situation in the field of contactless payments. The first chapter is devoted to the emergence and development of payment cards as a forerunner of contactless cards. The second chapter characterizes contactless cards as a new payment product. Additionally it also includes a description of the technology, which is used for this kind of cards. Chapter also deals with the arrival of contactless cards to Czech Republic and Slovakia. The topic of third chapter is Near Field Communication, special technology, which is used for contactless payments and also for the other forms of contactless payments, such as mobile payments. The fourth chapter talks about mobile services that are actually used for mobile payments. These services are not available in our region yet, but we expect their further expansion into European countries in the future. Finally, the last chapter includes an analysis of data, where we used statistical data of contactless payments in Slovakia and Czech Republic. The aim was to outline the development of contactless payments in individual quarters in both countries separately and to compare the data of contactless cards and payments in these countries.

Electrokinetics is a family of effects that induces motion of a liquid or a particle within a liquid in response to an external electric field. Using the intrinsic electrical properties of bacteria and of breast cancer cells, electrokinetics can be used to manipulate these particles for two different types of applications: tissue engineering and breast cancer detection. The first application studied the effects of electric fields on bacteria cells as well as calcium ions to potentially create a meniscus scaffold with hydroxyapatite ends for anchoring. In response to the electric field, calcium ions were able to deposit locally and simultaneously with cellulose growth. Bacteria cells were also studied to determine their response under an AC field. At low frequencies, bacteria demonstrated controlled movement caused by electroosmosis and dielectrophoresis with a net motion caused by a dielectrophoretic force. In the second application, the separation capabilities of different stages of breast cancer cells from the same cell line were tested using contactless dielectrophoretic (cDEP) devices. The electric field gradients in cDEP devices were altered to optimize selectivity and to determine an estimated membrane capacitance for each. From the results, the membrane capacitance of the early to intermediate stages proved to be very similar; however, late stage breast cancer cells have potential in being separated from early and intermediate stages. / Master of Science

A capillary electrophoretic procedure employing contactless conductivity detection (C4 D) has been developed for direct determination of the glycerol and mannitol polyalcohols in biological and pharmacological samples. Both glycerol and mannitol are fully separated from the sample matrix within very short times of 3.0 and 3.9 min., respectively, when using the optimized background electrolyte, 60 mM H3BO3 + 30 mM LiOH (pH 9.1). The limits of detection amount to 0.5 µM for glycerol and 0.3 µM for mannitol. The repeatability of the glycerol determination in real biological materials is characterized by the coefficient of variation values, 0.5 % and 3.2 %, for the migration time and the peak area, respectively. The procedure has been used to monitor the free glycerol concentration in adipose tissue microdialyzates. A physiological study has demonstrated that the lipolysis occurring during a sporting action can be stimulated by local application of adrenaline. The procedure has further been utilized to determine mannitol in a pharmacological preparation.

La mesure cardiaque sans contact réalisée grâce aux méthodes de photopléthysmographie sans contact est un domaine de recherche très actif. Depuis l'introduction en 2010 d'une nouvelle méthode de mesure avec des capteurs optiques d'entrée de gamme (webcam PC), les travaux de recherche se sont multipliés. Ainsi, on observe une plus grande diversité des méthodes proposées afin de réaliser la mesure. Egalement, la précision de la mesure a grandement progressé et les scénarios et possibilités d'usage de la technologie sont aujourd'hui très nombreux. Au cœur de ce processus de mesure, la segmentation dans l'image de la ou les zones d'intérêt est une étape clé. Nous proposons dans cette thèse une méthode innovante afin de réaliser la mesure photoplethysmographique sans contact en identifiant implicitement les zones de peau vivante dans la vidéo. Nous avons montré que notre approche permet d'améliorer la qualité de la mesure en favorisant les zones dans l'image où le signal est de plus grande qualité. Afin de rendre possible l'intégration de notre solution, nous avons proposé une nouvelle méthode de segmentation en superpixels, nommée IBIS, qui permet de réduire la complexité algorithmique de cette étape du traitement. Ce faisant, nous avons démontré la faisabilité de l'intégration de notre solution au sein d'une plateforme embarquée. Les différentes méthodes ont été évaluées au travers de plusieurs expérimentations afin de valider leurs performances. Notre méthode de segmentation en superpixels est comparée aux méthodes de l'état de l'art tandis que nous avons implémenté plusieurs des méthodes de mesure du signal photoplethysmographique afin de discuter de l'impact de notre approche sur la qualité de la mesure photoplethysmographique. Que ce soit pour la segmentation en superpixels ou pour l'estimation du rythme cardiaque sans contact, nous avons montré une importante plus-value de nos méthodes comparées à celles disponibles dans la littérature. Les différents travaux présentés dans ce document ont été valorisés au travers de publications en conférences et revue. / Heart-rate estimation performed with remote photoplethysmography is a very active research field. Since pioneer works in 2010, which demonstrated the feasibility of the measure with low-grade consumers’ camera (webcam), the number of scientific publications have increased significantly in the domain. Hence, we observe a multiplication of the methods in order to retrieve the photoplethysmographic signal which has led to an increased precision and quality of the heart-rate estimation. Region of interest segmentation is a key step of the processing pipeline in order to maximize the quality of the measured signal. We propose a new method to perform remote photoplethysmographic measurement using an implicit living skin identification method. Hence, we have shown that our approach lead to an improvement in both quality of the signal measured and precision of the heart-rate estimation by favoring more contributive area. As we are working with hardware integration constraint, we propose a new superpixels segmentation method which requires significantly less computation power than state of the art methods by reducing the algorithmic complexity of this step. Moreover, we have demonstrated the integration and real time capabilities by implementing our solution to an embedded device. All of our proposed method have been evaluated through different experimentations. Our new segmentation method, called IBIS, have been compared to state of the art methods to quantify the quality of the produced segmentation. To quantify the impact of our approach on the quality of the photoplethysmographic measure, we have implemented and compared state of the art methods with our proposed method. For both the superpixels segmentation and remote heart-rate estimation, our methods have shown great results and advantages compared to state of the art ones. Our works have been reviewed by the scientific community through several conference presentations and journal publications.

The unprecedented demand for performance in the latest technologies will ultimately require changes in the way we design cache. Emerging high density embedded memories such as Spin-Transfer Torque Random Access Memory (STTRAM) have emerged as a possible candidate for universal memory due to its high speed, low power, non-volatility, and low cost. Although attractive, STTRAM is susceptible to contactless tampering through malicious exposure to magnetic field with the intention to steal or modify the bitcell content. In this thesis, we explore various attack techniques on STTRAM and then propose a novel array-based sensor to detect the polarity and magnitude of such attacks and then propose two design techniques to mitigate the attack. With our research, we have been able to successfully implement and accurately detect an attack while providing sufficient compensation window (few ns to ~100 us) to enable proactive protection measures. Finally, we show that variable-strength ECC can adapt correction capability to tolerate failures with various strength of an attack.

Masters of Science / This thesis presents the results from work with three prototypes that use Near Field Communication technology to provide secure contactless mobile nancial services on mobile phones. / South Africa

O objeto de estudo deste trabalho é caracterizar um transdutor magnético de posição absoluto de longo percurso e robusto quanto à sua resposta dinâmica. O transdutor foi concebido na dissertação de mestrado do autor e denominada de ¨Régua Magnética¨na qual foi estudada a sua resposta estática. Diferentemente de outros transdutores magnéticos este tem como princípio de funcionamento a divisão do fluxo magnético entre dois caminhos distintos, cujas dimensões variam em função da movimentação da bobinas de excitação. Neste estudo analisa-se então a resposta dinâmica do transdutor, pois, quando o seu carro se desloca com velocidade constante, há uma modificação na grandeza física que é responsável pelo sinal de saída correlacionado à posição daquele carro. O estudo foi desenvolvido em dois transdutores de aproximadamente 2 m de comprimento confeccionados com lâminas de Fe-Si cortadas a laser. Os sinais de tensão induzida nas culatras, corrente e fluxo magnético no eletro-ímã do carro bem como o sinal de posição deste são coletados por um dispositivo digital e processados em um computador de modo a se poder obter as curvas estáticas e dinâmicas e assim compará-las. Com este propósito, foi desenvolvida uma bancada original de ensaio de transdutores de posição lineares para a medição da diferença dos sinais entre o caso estático e o dinâmico, denominado de diferença dinâmica, na qual foi empregado um transdutor de posição resistivo para a referência de posição, um sistema de aquisição de sinais para a medição das grandezas envolvidas no processo e um conjunto movimentador e servomotor para controle da velocidade e posição da parte móvel do transdutor. No final deste trabalho são comparados os resultados analíticos e experimentais obtidos como antes descritos. / The aim of this work is to characterize a long-span absolute magnetic position transducer that presents a robust dynamic response. The transducer was conceived by the MSc studies of the author and is called named “Magnetic Ruler” by which its static response was studied. Unlike other magnetic transducers, the magnetic ruler is based on the principle of the division of magnetic flux between two distinct magnetic paths that depends on the linear position of its movable part along the span of the transducer. This present study examines the dynamic response of the transducer when its movable part or car is moving with constant speed. Under such conditions, there is a change in the signal output that is correlated to the position of that car. The study was conducted by means of two transducers of approximately 2-m long laminations of Si-Fe that were laser cut. The voltage signals induced through the search coils on the end yokes, current and magnetic flux in the excitation coil on car, and the position are acquired by a digital device and processed by a computer. That is done to obtain the static and the dynamic curves and, thus, to allow the comparison between the two behaviors. With this objective, a specially built and unique test bench was developed to test linear position transducers under static and dynamic cases. The difference between the two results is called dynamic difference. That test bench employs a resistive position transducer to provide position reference, a signal acquisition system for measuring the quantities involved in the process, and a controlled traction system based on a servo system to control the speed and the position of the moving part of the transducer under test. At the end this work the analytical and experimental results obtained as described above are compared.