The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were introduced into the device, where changes in impedance were seen across multiple frequencies, indicating that the device is capable of detecting the presence of biologic elements within a system. Cell measurements were performed using NIH-3T3 fibroblasts.

No description available.

Inom modern informationsteknologi har självloggning fått en allt större roll. Dessa tjänster består vanligtvis av flera delar som behöver samverka för att ge en bra användarupplevelse. Eftersom fysiska enheter kompletteras med appar och webbtjänster behövs det en samspelad gränssnittsdesign för att användarna skall känna ett samband mellan tjänsterna och för att användarna skall använda flera delar. Detta kan göras på flera olika sätt, men genom olika designmål kan utvecklarna bland annat forma de olika delarna av tjänsterna mot samma mål eller spetsa dem för att uppfylla olika delar av tjänsten. Studien undersöker användarnas relation till olika gränssnitt och även olika tjänster. Denna uppsats xxnner att engagemang, personlighet och motivation påverkar valet av tjänst men även hur aktiva användarna är i ett flergränssnittsanvändande och vad de tycker om att behöva hantera flera gränssnitt. Denna uppsats belyser även hur användarna i sin jakt på större självin- sikt samlar och reflekterar över insamlad data över flera gränssnitt och enheter. Genom en kvalitativ intervjustudie med aktiva användare undersöks det närmare hur användarna upplever sitt samlande och hur tjänsterna fungerar och används över flera gränssnitt. Resultaten visar att användare ofta har problem med insamlingen av data och dessutom sällan använder sig av mer än ett eller kanske två gränssnitt. / In modern information technology Personal Informatics(PI) has gained an increasingly important role. Usually PI consists of several parts that need to work together to provide a great user experience. Since physical devices supplemented with apps and web services, to allow users to feel the connection between the services it is very important with a unified interface design. This can be done in several different ways, but through different design objectives you can shape services towards the same goal, or focus them to meet goals in other parts of the service. The study examines users' relationship with various interfaces and also various services. This paper finds that dedication, personality and motivation influences the choice of service but also, how active users are in a multi-use interface and what they think about having to manage multiple interfaces. This paper also highlights how the users in their quest for greater self-awareness collect and reflect on collected data over multiple interfaces and devices. Through qualitative interviews with active users we look closely at how users perceive their collecting and how the services works and are used across multiple interfaces. The results show that users often have problems with the collection of data and that they also rarely use more than one or maybe two interfaces.

Most women die of ovarian metastasis rather than the effects of the primary tumor. However, little is known about the factors that support the survival and secondary outgrowth of exfoliated ovarian cancer cells. In addition to genetic and molecular factors, the unique environment of the peritoneal cavity exposes ovarian cells to biophysical forces, particularly fluid shear stress (FSS). These biomechanical forces, only recently identified as a hallmark of cancer, induce rapid signaling events in attached and aggregated cells, a process termed mechanotransduction. The cellular responses to these forces and their impact on tumor initiation, progression, and metastasis are not understood. In order to delineate these phenomena, dynamic and syngeneic cell models are needed that represent the development of the disease and can be used in relevant engineered testing platforms. Thus, in an interdisciplinary approach, this work bridges molecular and cancer biology, device engineering, fluid mechanics, and biophysics strategies. The results demonstrated that even a low level of continual FSS significantly and differentially affected the viability of epithelial ovarian cancer cells of various stages of progression over time, and enhanced their aggregation, adhesion, and cellular architecture, traits of more aggressive disease. Furthermore, benign cells that survived FSS displayed phenotypic and genotypic changes resembling more aggressive stages of the disease, suggesting an impact of FSS on early stages of tumor development. After identifying a biological affect, we designed an in vitro testing platform for controlled FSS investigations, and we modeled the system fluid mechanics to understand the platform's performance capability. A cylindrical platform divided into annular sections with lid-driven flow was selected to allow continuous experiments sustainable for long durations. Tuning of the lid speed or fluid height resulted in a wide range of FSS magnitudes (0- 20 N/m2) as confirmed by analytical and numerical modeling. Further, detailed numerical modeling uncovered that FSS magnitudes experienced by cell aggregates were larger than previously observed, suggesting an even larger role of FSS in ovarian cancer. Finally, we built and engineered the designed platform to investigate changes in benign and cancer cells as a function of time and FSS magnitude. Device precision was balanced with biological consistency needs, and a novel platform was built for controlled FSS investigations. This work provides a foundational understanding of the physical environment and its potential links to ovarian cancer progression and metastatic potential. / Ph. D.

This research used human factors methods to investigate the relationship between no fault found (NFF) incident frequency and device usability. NFF reporting occurs when a medical device sent for repair is found to be operating normally. NFF incidents are one of the most recurrent failure modes, and therefore have considerable impact on cost, dependability and safety. An analysis of medical equipment maintenance data was conducted and six devices with a high NFF reporting frequency were identified. Semi-structured interviews and heuristics evaluations revealed that usability issues likely caused many of the NFF incidents. Other factors suspected to contribute to increased NFF reporting include accessory issues, intermittent faults and environmental issues. Finally, in order to validate the results, usability testing was conducted on three of the devices. 23 usability-related design flaws were identified. Therefore devices containing latent usability-related design flaws can be identified through analysis of medical equipment maintenance data.

This research used human factors methods to investigate the relationship between no fault found (NFF) incident frequency and device usability. NFF reporting occurs when a medical device sent for repair is found to be operating normally. NFF incidents are one of the most recurrent failure modes, and therefore have considerable impact on cost, dependability and safety. An analysis of medical equipment maintenance data was conducted and six devices with a high NFF reporting frequency were identified. Semi-structured interviews and heuristics evaluations revealed that usability issues likely caused many of the NFF incidents. Other factors suspected to contribute to increased NFF reporting include accessory issues, intermittent faults and environmental issues. Finally, in order to validate the results, usability testing was conducted on three of the devices. 23 usability-related design flaws were identified. Therefore devices containing latent usability-related design flaws can be identified through analysis of medical equipment maintenance data.

Minimally invasive or laparoscopic surgery has completely changed the focus of surgery becoming an alternative to various types of open surgery. Minimally invasive surgery avoids invasive open surgery as the operation is performed through one or more small incisions in the abdomen and using a small camera called laparoscope. Through these incisions, surgeons insert specialized surgical instruments to perform the operation resulting in less postoperative pain, shorter hospital stay, and faster recovery. However, the main problems during minimally-invasive surgery are the limited space for operating instruments and the reduced visibility and range of motion inside the patient’s body. During minimally-invasive surgery, one of the most difficult and time consuming surgical procedures is suturing and knot tying. This procedure significantly increases the operation time as it requires advanced techniques and extensive experience by surgeons.The main goal of this research is to investigate, design, and develop a new suturing instrument to facilitate suturing procedures during minimally invasive surgery.Qualitative research data was collected through interviews with a surgeon and six indepth observations of minimally invasive surgeries at Tampa General Hospital. Different design concepts and mechanisms were created using SolidWorks CAD software, and tested using SimulationXpress in order to identify dimensions, materials and expected performance of the design and its components. The prototypes of the device were made using a Dimension SST 768 FDM machine and tested by the surgeon to ensure that the final design meets the specified needs and criteria. This new device will eliminate the use of many different devices during the operation and allow the use of any type of suture. The proposed suturing device aims to benefit both patients and surgeons. For surgeons, the new device aims to decrease the number of steps for laparoscopic suturing through an intuitive and ergonomic design. For patients, the proposed device will reduce time during surgery and under general anesthesia leading towards improved health care.

Orientador: Hugo Enrique Hernandez Figueroa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T11:21:19Z (GMT). No. of bitstreams: 1 Borges_FabianoRodrigo.pdf: 3954935 bytes, checksum: fd0b1eeed8a2cd4e9566f172cdf86b81 (MD5) Previous issue date: 2009 / Resumo: O trabalho mostra o desenvolvimento de um filtro na faixa de frequência de micro-ondas e sua construção usando ressoadores dielétricos de alta permissividade elétrica. A partir da definição matemática de uma função de transferência do tipo entrada-saída, que caracteriza um filtro, e do uso da teoria de síntese de redes, vista de um modo bastante simplificado, mostra-se como construir um circuito elétrico que realiza fisicamente a função de transferência do filtro. Em frequência de micro-ondas, contudo, elementos de parâmetros concentrados - resistores, indutores e capacitores - não se comportam como esperado, e a resposta de um circuito elétrico nesta frequência não é como a projetada. Para realizar fisicamente este circuito elétrico é necessário desenvolver conceitos eletromagnéticos, que passam pela definição de uma ferramenta importantíssima, chamada inversor de impedância, e seu equivalente acoplamento eletromagnético. Para restringir o trabalho, tratamos de filtros passa-faixa de banda estreita, o tipo mais comumente utilizado em aplicações de micro-ondas. A conversão do circuito elétrico obtido para um circuito constituído por elementos de parâmetros distribuídos é mostrada e fecha o ciclo teórico do trabalho. No campo de práticas experimentais de laboratório, medem-se parâmetros que permitem caracterizar o filtro eletromagnético obtido usando-se uma análise estatística rigorosa. Os resultados obtidos mostram que é possível partir de uma função matemática abstrata e chegar a um dispositivo de micro-ondas físico que provê a resposta projetada. Além disso, o uso de cerâmicas com permissividade elétrica elevada levou ao desenvolvimento de novas técnicas de alimentação para filtros do tipo projetado, e o requisito de ter-se uma grande banda de rejeição levou ao desenvolvimento de uma nova geometria para as cerâmicas usadas na construção do filtro. / Abstract: This work shows the development of a filter at microwave frequencies and its construction by means of dielectric resonators of high electric permittivity. Starting by the mathematical definition of a transfer function such as the kind input-output, which characterizes the filter, and the use of network synthesis theory, shown in a very simply way, one shows how to built an electric circuit that implements the filter's transfer function. At microwave frequencies, however, concentrated parameter elements - resistors, inductors and capacitors - do not behave as expected, and the output of an electric circuit at this frequency is not like the projected one. To implement this electric circuit, one needs to develop electromagnetic concepts, such as a very important tool, called impedance inverter, and its equivalent electromagnetic coupling. To restrain the scope of this work, we choose to develop bandpass filters of narrow bandwidth, the most common type used at microwave applications. The conversion from the electric circuit obtained for a circuit made by distributed parameter elements is shown and closes the theoretical cycle of this work. Regarding laboratory experimental practices, parameters are measured towards the characterization of the designed electromagnetic filter by means of a rigorous statistics analysis. The results obtained show that it is possible to begin with an abstract mathematical function and to end up with a microwave device that exhibits the designed response. Besides, the use of ceramics with high permittivity led to the development of new techniques for feeding the filters like the ones presented here, and the requirement of having a big stopband led to the development of a new geometry for the ceramics used to build the filter. / Universidade Estadual de Campi / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

No description available.

Pour mettre en relation les propriétés rhéologiques et la structure méso/microscopique d'un système modèle ou complexe, l'utilisation de la rhéo-optique est indispensable. Nous avons donc développé une cellule d'observation sous cisaillement adaptée à la microscopie confocale. Ce dispositif, breveté et nommé RheOptiCAD®, permet le cisaillement contrôlé d'un échantillon quelconque placé entre 2 plans parallèles en translation. Grâce à un système à dépression, la mise en place de l'échantillon est simple et rapide tout en assurant des propriétés optiques répétables et reproductibles (planéité, parallélisme). Par ailleurs, la température au sein de l'échantillon peut être régulée de façon à imposer une contrainte thermique, cause de nombreuses modifications de la mésostructure d'un système alimentaire. La cellule d'observation sous cisaillement permet donc de suivre l'évolution et la dynamique des changements de structures conséquences d'un traitement thermo-mécanique imposé. Un logiciel de pilotage et d'acquisition des données a été développé pour rendre son utilisation plus conviviale. La validation du fonctionnement de l'outil et de ses fonctionnalités a tout d'abord été réalisée sans échantillon puis à l'aide d'un système modèle contenant des particules fluorescentes dont le mouvement était suivi. Par la suite, dans le but de tester les potentialités de ce nouvel outil tout en développant la méthodologie de son utilisation, et en particulier l'équilibre entre propriétés optiques et mécaniques des échantillons, nous avons travaillé avec de la pâte de farine. Ce système alimentaire bien connu et maîtrisé d'un point de vue rhéologique au laboratoire présente des caractéristiques intéressantes dans ce cadre. L'évolution du réseau de gluten au cours d'un cisaillement oscillatoire en fonction de la formulation de la pâte a été étudiée. Grâce à une analyse d'image basée sur la morphologie mathématique, nous avons pu mettre en évidence des changements de structures au cours du temps. De même, à l'aide des capacités thermiques de la cellule de cisaillement, nous avons étudié le positionnement et le mouvement des lipides endogènes à l'interface air-protéine lors de la fermentation. Notre cellule d'observation sous cisaillement constitue donc un nouvel outil de caractérisation dynamique de systèmes complexes couplant rhéologie et microscopie. Son optimisation principale réside dans la mise en place d'un capteur de force, mesurant les contraintes mises en jeu lors des déformations imposées. / Rheo-optic is a recent technique which can be used to create links between rheological properties and meso/microsctructures of model or complex (food) systems. A novel rheo-optical shearing device was designed for studying this relationships within complex food systems. The device has been build to be adapted on an inverted confocal microscope. Specifications of the shear cell are: a) a controlled translational shear between 2 parallel plates with three different motion modes (continuous, oscillatory, strain jump); b) a thermal control; and c) an observation on an inverted confocal microscope. Due to a vacuum system, the set up of an experiment is easy and fast ensuring reproducible optical properties (planarity, parallelism). Temperature, responsible of numerous modifications of structures in a food matrix, is also controlled. A piloting software allows an easy use of the shear cell. Validation of the motion modes has been carried out using a microgel, containing fluorescent probes (spheres) and tracking some of the particles. Next, in order to test and develop methods of observation under shear, taking into account the optical-mechanical balance, bread dough observation has been performed. Well known and described in the lab, bread dough is a dispersion of air bubbles and starch granules in a gluten network. Evolution on this gluten network depending on the formulation of the bread dough has been studied under oscillatory shearing. The composition effect on the microstructure and its evolution were observed and will be commented. Image analysis based on grayscale mathematical morphology has been carried out in order to try to quantify the rheological properties and microstructures. Finally, by a controlled increase of temperature, the growth of an air bubble in bread dough containing yeast was followed during proofing. The influence and the disposition of fat globules at the bubble air-protein interface along this growing process were followed. Thanks to the rheo-optical device, images of microstructures obtained under controlled shear are compared to their rheological behaviour.