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Dissertations / Theses on the topic 'Bio-medical Applications'
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Puybareau, Elodie. "Motion analysis for Medical and Bio-medical applications." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1063/document.
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L’analyse du mouvement, ou l’analyse d’une séquence d’images, est l’extension naturelle de l’analyse d’images à l’analyse de séries temporelles d’images. De nombreuses méthodes d’analyse de mouvement ont été développées dans le contexte de la vision par ordinateur, incluant le suivi de caractéristiques, le flot optique, l’analyse de points-clef, le recalage d’image, etc. Dans ce manuscrit, nous proposons une boite a outils de techniques d’analyse de mouvement adaptées à l’analyse de séquences biomédicales. Nous avons en particulier travaillé sur les cellules ciliées qui sont couvertes de cils qui battent. Elles sont présentes chez l’homme dans les zones nécessitant des mouvements de fluide. Dans les poumons et les voies respiratoires supérieures, les cils sont responsables de l’épuration muco-ciliaire, qui permet d’évacuer des poumons la poussière et autres impuretés inhalées. Les altérations de l’épuration mucociliaire peuvent être liées à des maladies touchant les cils, pouvant être génétiques ou acquises et peuvent être handicapantes. Ces maladies peuvent être caractérisées par l’analyse du mouvement des cils sous un microscope avec une résolution temporelle importante. Nous avons développé plusieurs outils et techniques pour réaliser ces analyses de manière automatiques et avec une haute précision, à la fois sur des biopsies et in-vivo. Nous avons aussi illustré nos techniques dans le contexte d’éco-toxicité en analysant le rythme cardiaque d’embryons de poissonsMotion analysis, or the analysis of image sequences, is a natural extension of image analysis to time series of images. Many methods for motion analysis have been developed in the context of computer vision, including feature tracking, optical flow, keypoint analysis, image registration, and so on. In this work, we propose a toolbox of motion analysis techniques suitable for biomedical image sequence analysis. We particularly study ciliated cells. These cells are covered with beating cilia. They are present in humans in areas where fluid motion is necessary. In the lungs and the upper respiratory tract, Cilia perform the clearance task, which means cleaning the lungs of dust and other airborne contaminants. Ciliated cells are subject to genetic or acquired diseases that can compromise clearance, and in turn cause problems in their hosts. These diseases can be characterized by studying the motion of cilia under a microscope and at high temporal resolution. We propose a number of novel tools and techniques to perform such analyses automatically and with high precision, both ex-vivo on biopsies, and in-vivo. We also illustrate our techniques in the context of eco-toxicity by analysing the beating pattern of the heart of fish embryo
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Wu, Hao. "Efficient Algorithms for Applications in Bio-medical Data Processing." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23411.
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In this thesis, new high-performance algorithms and machine learning models are developed to solve challenging problems in the bio-medical field. We first focus on developing high performance parallel algorithms for all pairwise computation in bio-informatics applications such as construction of transcription factor interaction networks. We then develop an automatic optic disc detection algorithm using sparse dictionary learning in retinal images for the medical field. All pairwise computation is defined as performing computation between each and every pair of the elements in a given data set. Many of such applications require multiple terabytes of main memory and take multiple peta floating point operations to complete. Thus, large HPC clusters and highly efficient parallel algorithms are vital. Traditional methods for large scale distributed computing usually suffer from scalability issues. This thesis introduces some new effective and efficient parallel algorithm designs. We first design an efficient one-dimensional (1D) ring algorithm which doubles the block size compared to traditional ring algorithms and reduces the total communication cost by half. Based on the 1D ring we further develop a two-dimensional (2D) ring algorithm. When increasing the compute nodes, instead of reducing the block size, we make multiple copies of the original data blocks in the 1D ring and distribute them across the added compute nodes in the other dimension. By properly organizing the compute nodes the communication overhead can be reduced to a minimum. Experiments on supercomputer show that our new algorithms perform better in efficiency and scalability compared to conventional methods for large scale all pairwise computation in bio-informatics applications. The optic disc is one of the most important fundus structures in the retinal image of the human eye. Effective and accurate detection of the optic disc in a colour retinal image is a challenging topic. Inspired by the fact that humans can locate optic disc in a retinal image by observing local features, a local feature spectrum analysis (LFSA) method is proposed in this thesis. A local feature dictionary is defined for the reconstruction process of optic disc candidate images. The frequency of each atom, or spectrum in the dictionary is utilized along with sparse dictionary selection method for classification. Our innovative approach can effectively detect optic disc in a retinal image and the influence caused by the variable spatial positions of local features can be effectively reduced. Unlike most conventional approaches, segmentation of blood vessels is not required in our method. Our LFSA method is simple and robust, making it one of the best options for automated screening systems in medical image processing. Performance evaluation of our approach is conducted with the largest publicly available data set and comparisons against conventional approaches are made. Results indicate that the LFSA method achieves more accurate and reliable optic disc detection results.
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Alhazime, Ali. "Development of novel compact laser sources for bio-medical applications." Thesis, University of Dundee, 2014. https://discovery.dundee.ac.uk/en/studentTheses/ec837854-dd0c-44bb-9b1c-dd4a1fa181d3.
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The focus of this thesis relates to the development and characterisation of novel semiconductor based lasers sources tunable in the broad spectral ranges that are unattainable by conventional lasers due to a lack of suitable laser gain materials. Within the first part, the broad gain spectrum from quantum dot (QD) materials is seen to be an appealing feature for the development of broadly tunable lasers, broadband amplifiers and ultra short pulse generation. As has been previously shown quantum-dot external-cavity passively mode-locked lasers (QD-ECMLLs) are excellent candidates for versatile ultra short pulse generation. This is due to the flexibility that anexternal-cavity mode-locking configuration can offer in terme of a broad tunability for both repetition rate and wavelength which could be achieved. Similarly quantum-dot semiconductor optical amplifiers (QD-SOA) are suitable for the broadband pulse power amplification. Furthermore, master oscillator power amplifier (MOPA) picosecond optical pulse sources using all chirped QD structures were investigated using the MOPA system consisting of two parts, firstly QD-ECMLL and secondly a tilted taper QD-SOA. A further investigation involved a comparison between 1st-order diffraction grating and 2nd-order diffraction grating for this tunable QD-MOPA. The result found was the maximum fundamental mode-locking (FML) wavelength tuning range. Nearly 100 nm (from 1187nm to 1283nm) wavelength tuning range was achieved under a 900 mA current applied to the gain chip with a 2nd-order grating diffraction. Furthermore it was also demonstrated that the peak power spectral density achieved with the 2nd-order diffraction (max; 31.4dBm/nm) is much higher (2-4dB) than that from the 1st-order diffraction under similar conditions. The narrowest optical spectrum width was achieved from the 2nd-order diffraction and the narrowest pulse of 13 ps was found for the setup with the 1st-order diffraction grating. The wavelength tuning range from both orders can be amplified by increasing the injection current of the gain chip without deteriorating the stability of FML. The second part of this thesis focussed on experimental testing of EP-VECSELs, also known as electrically-pumped semiconductor disc lasers (SDLs), which produce high multi watt output power with diffraction limited output beam profile. EP-VECSELs have great potential within the applications where the watt level CW output power and mode-locked light with picosecond pulses sources are required.
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Hasan, Saad Ahmed. "Design of low power electronic circuits for bio-medical applications." Thesis, University of Liverpool, 2011. http://livrepository.liverpool.ac.uk/3024667/.
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The operational transconductance amplifier, OTA is one of the basic building blocks in many analogue circuit applications. The low power consumption is an essential parameter in modem electronic designs for many areas particularly for portable devices and biomedical applications. For biomedical applications, the low- power low-voltage OTA-C filters operating at low-frequency ranges are desired. The low-power, low-voltage operation of electronic devices is very important for applications such as hearing aids, pacemakers, and EEG. The importance of such operation is due to the need to implant these electronic circuits inside the body of the patient for long times before re-charging or replacing the batteries as for pacemakers and future hearing aids. The small size lightweight wearable EEG systems are preferable for applications ranging from epilepsy diagnosis to brain-computer interfaces. The low power consumption is achieved by operation at very small levels of current. So, in such applications the operation in the nano-ampere current range is essential to ensure power consumption of nW or few uW. Such very small currents are obtained through the operation of MOS transistors in their sub-threshold regime. The design space in such applications is restricted by their specifications which in turn based on the nature of the application. In this work, the design and implementation of OTA-C filter topologies for two bio-medical applications are made and discussed. Those applications are represented by hearing aids and EEG applications. In hearing aids, the work focused on cochlear implant and specifically on its most important stage represented by the filter. Four OTA-C filter topologies are proposed and two of them are tested experimentally. For the filter in a hearing aid system, besides its low power operation, it is required to operate with a relatively high dynamic range of 60dB and above. The dynamic range is the operation space of the filter that specified by the range of signals which can process properly. It is bounded by the maximum power signal less than its distortion overhead level to the minimum power signal more than its noise floor. The maximum signal level the filter can perform properly represents its input linear range. The challenge in CMOS OTA sub-threshold operation is the very small input linear range which makes it extremely difficult to build low-power consumed OTA-C filters with a wide dynamic range, DR. In this work, an OTA with an input linear range of ±900mV for total harmonic distortion, THD<5% is proposed using MOSFET bumping and capacitor attenuation techniques, combined for the first time. The minimum signal level the filter can distinguish from noise is still relatively small with the use of appropriate OTA architecture and using the gm/ID methodology for MOSFET sizing. So, programmable CMOS OTA-C band-pass filter topologies operating in sub-threshold region with a dynamic range of 65dB for use in bionic ears were proposed. The power consumption for the proposed filters is in nano- Watt range for their frequency range of (lOO-I Ok) Hz. Also, a 4-channel OTA-C filter bank is designed and tested. The EEG signals have small amplitudes and frequency bands ranges of uV'S and (l-40) Hz respectively. The important issue is to design filters with small noise floor with white dominant. This is achieved with the proposed OTA which is of relatively simple architecture and with operation in the deep weak-inversion region using ±1.5V supply rails. The OTA-C filter has power consumption in the pico-Watt range for 0, e, and a signals and less than 3nW for B signals. Another topology is suggested for future work.
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Hartleb, Carina. "Creation and Evaluation of Solid Optical Tissue Phantoms for Bio-Medical Optics Applications." Thesis, Linköping University, Department of Biomedical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-3607.
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Because of their compatibility and precise results bio-optical methods based on measurements of the optical tissue properties gain importance in non-invasive medical therapy and diagnostic. For development and standardization of medical devices optical phantoms are suitable. The present report handles the creation and evaluation of solid tissue phantoms, made up of Agar, Vasolipid and ink utilizing different mixture ratios. After cutting the models in slices of 0.2 to 1.1 mm thickness the absorption- and scattering coefficient were measured using a collimated laser beam setup. As result of the study a formula for the preparation of solid optical tissue phantoms with desired optical properties was found, that is valid for models containing 1.12 % Agar.
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Ramosoeu, Makhabo Khabiso Ellen. "Characterisation and static behaviour of the DMLS Ti-6AI-4V for Bio-medical applications." Thesis, Bloemfontein: Central University of Technology, Free State, 2015. http://hdl.handle.net/11462/275.
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Thesis (M. Tech. (Engineering: Mechanical)) -- Central University of Technology, Free State,The Centre for Rapid Prototyping and Manufacturing (CRPM) at the Central University of Technology, Free State (CUT) manufactures implants using Electro Optical Systems (EOS) titanium Ti-6Al-4V alloy powder (further referred to as EOS Ti64 powder) by means of Direct Metal Laser Sintering (DMLS) process on the EOSINT M 270 machine. For this reason, there is a need to characterise and acquire knowledge of the basic properties of direct metal laser sintered EOS titanium Ti-6Al-4V alloy samples (further referred to as DMLS Ti64 samples) under static tensile loading in order to provide the CRPM with engineering design data. The first objective of this Master’s study is to acquire the characteristics of EOS Ti64 powder in order to ascertain its suitability in the DMLS process. Secondly, the study aims to assess tensile properties and elastic constants of DMLS Ti64 samples produced from the set process parameters of EOSINT M 270 machine. Thirdly, it is to investigate microstructures of DMLS Ti64 samples subjected to different heat treatment techniques which will eventually assist in the determination of a suitable heat treatment technique that will yield higher ductility. Finally, the study aims to validate the static behaviour of DMLS Ti64 samples subjected to the static tensile loading up to a yield point in order to determine failure due to yielding. The samples were manufactured at CRPM Bloemfontein. The metallographic examinations, heat treatment and the determination of mechanical properties were done at the CSIR in Pretoria. Optical Microscope (OM) and Scanning Electron Microscope (SEM) were used to determine microstructures of DMLS Ti64 samples while Energy Dispersive X-Ray (EDX) analyses were performed using SEM. The samples were heat treated at temperatures of 700, 1000 and 1100°C respectively, and subsequently either cooled with the furnace, air or were water quenched. The mechanical property tests included tensile, hardness and determination of elastic constants. The static behaviour of DMLS Ti64 samples under static tensile load up to a yield point was predicted and verified using ABAQUSTM Finite Element Analysis (FEA). The stress-strain curves from ABAQUSTM were interpreted using MDSolid program. The point of interest was Von Mises yield stress at 0.2% offset, in order to determine failure due to yielding. EOS Ti64 powder particles were spherical in shape and the alpha and alpha+beta phases were identified. As-laser sintered samples possess a very fine and uniform alpha case with islands of martensitic plates; samples were brittle and showed low levels of ductility with an average elongation of 2.6% and an area reduction of 3.51%. Ultrasonic test results showed that DMLS Ti64 samples have Young’s modulus of 115 GPa, Shear modulus of 43 GP, a bulk modulus of 109 GPa and Poisson’s ratio of 0,323 while the density was 4.4 g/cm3. Slow cooling of DMLS Ti64 samples from 1000 and 1100oC resulted in a microstructure constituted more by the alpha phase of lower hardness than those from 700oC and as-laser sintered samples. High hardness was obtained by water quenching. The water quenched samples showed martensitic transformation and high hardness when compared to furnace cooled samples. Beta annealing tailored a microstructure of as-laser sintered samples into a lamellar structure with different lath sizes as per cooling rate. Beta annealing improved ductility levels up to 12.67% elongation for samples furnace cooled for 4 hours and even higher to 18.11% for samples furnace cooled for 34 hours, while area reduction increased to 25.94% and 33.39%, respectively. Beta annealing conversely reduced yield strength by 19.89% and ultimate tensile strength was reduced by 23.66%. The calculated maximum Von Mises stresses found were similar to the FEA interpreted results. The average percentage error, without the stress concentration factor, was approximately 8.29%; with the stress concentration factor included, it was 0.07%. The small reaction forces induced in both x-axis and z-axis contributed to this error of 0.07% between the calculations and ABAQUSTM FEA results. Samples that were not heat treated fell outside the Von Mises criterion and failed due to yielding. This justified the brittleness found in the tensile test results where elongation and area reduction were 2.6% and 3.51% respectively. However, all samples that were heat treated fell within the Von Mises criterion. The objectives of this study were achieved; the mechanical properties were similar to those of standard specification for wrought annealed Ti-6Al-4V alloy for surgical implant applications and EOS GmbH manufacturer’s material data sheet. DMLS Ti64 samples must be beta annealed in order to attain higher levels of ductility. A recommendation was made to further investigate the effect of heat treatment on the other mechanical properties. Furthermore, detailed results of basic properties of DMLS Ti64 samples are provided in the appendices in chart format and were written on a CD disc.
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John, Sween. "A Study of the Synthesis and Surface Modification of UV Emitting Zinc Oxide for Bio-Medical Applications." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc10990/.
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This thesis presents a novel ZnO-hydrogel based fluorescent colloidal semiconductor nanomaterial system for potential bio-medical applications such as bio-imaging, cancer detection and therapy. The preparation of ZnO nanoparticles and their surface modification to make a biocompatible material with enhanced optical properties is discussed. High quality ZnO nanoparticles with UV band edge emission are prepared using gas evaporation method. Semiconductor materials including ZnO are insoluble in water. Since biological applications require water soluble nanomaterials, ZnO nanoparticles are first dispersed in water by ball milling method, and their aqueous stability and fluorescence properties are enhanced by incorporating them in bio-compatible poly N-isopropylacrylamide (PNIPAM) based hydrogel polymer matrix. The optical properties of ZnO-hydrogel colloidal dispersion versus ZnO-Water dispersion were analyzed. The optical characterization using photoluminescence spectroscopy indicates approximately 10 times enhancement of fluorescence in ZnO-hydrogel colloidal system compared to ZnO-water system. Ultrafast time resolved measurement demonstrates dominant exciton recombination process in ZnO-hydrogel system compared to ZnO-water system, confirming the surface modification of ZnO nanoparticles by hydrogel polymer matrix. The surface modification of ZnO nanoparticles by hydrogel induce more scattering centers per unit area of cross-section, and hence increase the luminescence from the ZnO-gel samples due to multiple path excitations. Furthermore, surface modification of ZnO by hydrogel increases the radiative efficiency of this hybrid colloidal material system thereby contributing to enhanced emission.
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John, Sween Vaidyanathan Vijay Varadarajan. "A study of the synthesis and surface modification of UV emitting zinc oxide for bio-medical applications." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/permalink/meta-dc-10990.
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Dobbelaar, Martinus. "Conception et réalisation de systèmes d’exposition plasma nanoseconde pour des applications biomédicales." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3040/document.
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Les plasmas froids dans l’air à pression atmosphérique ont trouvé de nombreuses applications ces dernières années. Grâce à une chimie très réactive, les plasmas froids offrent une solution prometteuse pour le traitement bio-médical. Dans ce contexte, deux dispositifs d’exposition au plasma sont présentés :• le premier dispositif permet de générer des DBD (Décharges à Barrière Diélectrique) sur une échelle de temps nanoseconde (ns-DBD). L’échantillon biologique joue le rôle d’une électrode. La décharge se développe dans l’intervalle d’air entre la surface du diélectrique et l’échantillon biologique.• le.second dispositif d’exposition permet de générer des DBD de surface sur une échelle de temps nanoseconde (ns-SDBD). La décharge se forme le long de la surface du diélectrique, à proximité de l’électrode active. Pendant l’exposition au plasma, l’échantillon est placé face à l’applicateur. Contrairement à l’applicateur DBD, la décharge n’est pas directement en contact avec la solution biologique.Les deux systèmes d’exposition au plasma sont conçus de façon similaire, leurs dimensions autorisent l’exposition d’un échantillon biologique placé dans une boite de Petri classique. La cible biologique est un ensemble de cellules cancéreuses placées dans une solution de culture. Le travail présenté est essentiellement expérimental. Il se concentre sur la caractérisation électrique des décharges. Le plasma est créé avec des impulsions haute tension (de 4 kV à 11 kV), sur des temps très courts (de 10 ns à 14 ns de largeur) et avec des temps de montée brefs (2,5 ns, en fonction du générateur utilisé). Dans la configuration ns-DBD, l’énergie déposée par le plasma par impulsion est de l’ordre du mJ. En configuration ns-SDBD, l’énergie déposée est calculée, elle est de l’ordre de quelques dizaines de μJ. Une étude préliminaire sur le traitement d’échantillons biologiques est réalisée dans la configuration ns-SDBD. La viabilité de cellules de glioblastome est présentée en fonction de l’énergie déposée dans le plasma par impulsion. Selon les résultats de cette première étude, le plasma ns-SDBD a un effet sur la viabilité des cellules exposées dans les conditions décritesCold plasmas in atmospheric pressure air have been used in many different applications in the past few years. Because of its high chemical reactivity, cold plasma treatment appears to be a promising solution for biomedical applications. In this context the study and realization of nanosecond plasma exposure devices for biomedical applications are presented :• the first exposure device generates DBD (Dielectric Barrier Discharge) on a nanosecond time scale (ns-DBD). The biological sample acts as an electrode. The discharges develops in the air gap be- tween the dielectric layer and the biological sample.• The second exposure device generates surface DBD on a nanosecond time scale (ns- SDBD). The discharge develops along the dielectric layer surface close to an active electrode. During plasma exposure, the biological sample faces the discharge device. By contrast to the DBD configuration, the discharge is not in direct contact with the surface of the solution.Both exposure devices are designed in a same way,. the dimensions allow plasma treatment of biological sample contained in a standard Petri dish. The biological targets are cancer cells in a liquid culture medium. The work is mainly experimental. It focuses on the electrical characterization of discharges. The plasma is created using short (10-14 ns of FWHM) high-voltage (up to 4 or 11 kV) pulses of fast rise times (2-5 ns depending on the pulse generator). In the ns-DBD configuration the energy deposited into plasma per pulse is in the order of millijoule. In the ns-SDBD configuration, we calculated the energy deposited into plasma per pulse in a range of tens of μJ. A preliminary study on treatment of biological samples by ns-SDBD plasma is performed. The glioblastoma cells viability was presented as a function of the energy deposited into plasma per pulse. According to this preliminary result the ns-SDBD plasma has an influence on the viability of the cells in the given conditions
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Moothoo, Julien. "Analyse de la faisabilité d’éco-conception de pièces composites à base de ressources renouvelables pour applications médicales." Thesis, Orléans, 2013. http://www.theses.fr/2013ORLE2052/document.
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La présente étude traite de l’éco-conception d’une pièce structurale, de type poutre tubulaire, en stratifié bio-composite à base de fibres de lin. A cette pièce à concevoir est associé un cas de charge mécanique combinant flexion et torsion et une tenue face aux produits détergents-décontaminant utilisés en environnement médical. Cette étude a pour objectif de montrer la faisabilité d’employer comme architecture de renfort, une mèche de lin pour la réalisation de la pièce. Ce renfort a la particularité d’être constitué de fibres alignées dont la cohésion est assurée par la présence d’un liant par opposition aux fils constituées de fibres retordues. Tout d’abord, pour établir un cahier des charges de fabrication à partir de ceux déjà en vigueur, le comportement mécanique du bio-composite à l’échelle du pli, puis à celui du stratifié et enfin à l’échelle de la poutre stratifié a été modélisé et des critères de conception et de dimensionnement portant sur la rigidité en flexion et en torsion ont été développés de façon analytique. Associée à cette approche et au choix du renfort, le procédé d’enroulement filamentaire a été retenu pour la mise en oeuvre de la pièce. Afin de montrer la compatibilité de la mèche en entrée et le procédé sélectionné, une étude du comportement en traction de la mèche visant à étudier l’effet des paramètres du procédé sur les propriétés mécaniques de la mèche a été réalisée. Cette deuxième phase a été poursuivie par la réalisation de prototypes, suivant le cahier des charges de fabrication établit, qui ont ensuite été analysés en termes de qualité et de performances mécaniques. La corrélation entre ces résultats et ceux obtenus par l’étape de dimensionnement a permis de valider l’approche. Enfin, dans le but d’intégrer l’interaction avec l’environnement opératoire dans le dimensionnement de la pièce, une étude de la durabilité a été réalisée. Celle-ci permet d’établir des stratégies de dimensionnement pour répondre à l’applicationThis study aims at eco-designing a structural part, of a hollow beam type, using a laminated flax fibre based bio-composite. The part needs to satisfy a given bending and torsion load case and show compatibility with the cleaning products used in the medical environment. The objective of the study is to investigate the potential of using a flax tow as the reinforcement input for the manufacturing of the beam. The particularity of the reinforcement is that it consists of an assembly of aligned flax fibres held together by a binder as opposed to spun yarns. First, in order to establish the required manufacturing specifications, the mechanical behaviour of the bio-composite at the ply scale, at the laminated and finally at the laminated beam scale was modelled. From this modelling, design and dimensioning criteria based on bending and torsional stiffness were developed analytically. Combining this approach with the choice of the reinforcement, the wet-filament winding process was chosen to manufacture the part. Thus, the tensile behaviour of the flax tow was studied in relation to the process parameters to demonstrate their compatibility. This second phase was followed by the manufacturing of prototypes according the established specifications which were then analysed in terms of quality and mechanical performance. The correlation between experimental results and the model predictions was used to validate the dimensioning approach. Finally and in order to incorporate the interaction of the part with the environment, a durability study was conducted. The latter allows to put forward different dimensioning strategies to meet the required specification
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Yeo, Woon Gi. "Terahertz Spectroscopic Characterization and Imaging for Biomedical Applications." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1430825935.
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Nagai, Andrii. "Investigation of SiPM physics parameters down to cryogenic temperatures and for a bio-medical application." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS552/document.
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Les Photomultiplicateurs Silicium (SiPM) sont devenus aujourd’hui des détecteurs de lumière visible, applicables dans de nombreux domaines comme la Physique des Hautes Énergies, les expériences Neutrinos, la détection de fluorescence, pour des applications de biophotonique ou d’imagerie médicale. La première partie de ma thèse concerne l’étude des divers paramètres physiques des SiPM en fonction de température T. En particulier, des composants récents (2015) de KETEK ayant diverses caractéristiques technologiques comme des jonctions p/n ou n/p, avec ou sans « trench » entre cellules, différentes épaisseurs de couches épitaxiales, etc… ont été étudiés dans la gamme de T de 308.15 K (+35°C) à 238.15 K (-35°C). En plus, des composants Hamamatsu de production 2011, ainsi que de production 2015 avec des caractéristiques technologiques améliorées (faible bruit), ont été testés dans la gamme 318.15 K (+45°C) à 98.15 K (-175°C). Pour ces études, j’ai participé à la conception, l’installation, la mise en service et la calibration d’un banc cryogénique destiné aux caractérisations électriques, optiques, et en température, des SiPM. J’ai développé une procédure d’analyse automatisée, capable de traiter en un temps très court une énorme quantité de données expérimentales (i.e. dizaines de Gb/détecteur), et de fournir une information rapide et précise sur les principaux paramètres et leur dépendance en T. J’ai développé un modèle physique décrivant les courbes IV en DC pour différentes T. Ce modèle proposé reproduit bien la forme de la courbe IV dans une large gamme de courants allant de 10⁻¹² à 10⁻⁵ A sur toute la zone de fonctionnement des divers détecteurs. Ainsi, le modèle IV peut être utilisé comme un outil simple et rapide pour déterminer les paramètres du SiPM comme le VBD, la forme de la courbe PGeiger en fonction de Vbias, ainsi que la plage des tensions de fonctionnement. La comparaison de ces paramètres avec ceux obtenus en mesure AC, et analysés par la procédure automatisée, sont en bonne concordance. La seconde partie de ma thèse a porté sur l’étude de composants SiPM spécialement adaptés à une application biomédicale. Il s’agit d’une sonde intracérébrale, sensible à l’émission β (Nβ) de molécules marquées par un traceur radioactif, injectées dans le cerveau d’un animal vivant. Le but étant de construire un nouveau "modèle animal" de maladies humaines telles que les maladies neuro-dégénératives ou neuropsychiatriques et la croissance de tumeurs. Cette sonde se compose d’un SiPM de très petite taille, bas bruit, couplé à une fibre scintillante, suivie d’une électronique de lecture spécifique, miniaturisée, à faible consommation. Ces SiPM ont été choisis comme les plus adaptés à notre application : deux SiPM de KETEK de 0.5x0.5 mm² (spécialement développés par cette compagnie pour nos besoins), et un SiPM standard de 1.3x1.3 mm² de Hamamatsu, tous ayant des μ-cellules de 50 × 50 μm². Pour chaque composant, les paramètres G, DCR et la sensibilité β ont été mesurés en fonction de Vbias et T. Les résultats obtenus montrent que le faible champ de vue des nouvelles structures KETEK permet une bonne amélioration du DCR. Cependant ce faible champ de vue entraîne une perte de collection de lumière due à l’épaisseur de la couche de résine époxy de protection, et à l’angle d’acceptante de la fibre. Comme la sensibilité β est un compromis entre le PDE et le DCR, les SiPM de KETEK montrent au final des performances voisines de celles de Hamamatsu. Les résultats préliminaires démontrent que la sensibilité β de KETEK peut être améliorée significativement en utilisant une lentille de focalisation entre la fibre scintillante et le SiPM, ou en diminuant l’épaisseur de la couche de résine époxy de protectionSilicon PhotoMultiplier (SiPM) detector has become a suitable visible light/photon detector for many applications like high energy physics and neutrino experiments, fluorescence detection, bio-photonics and medical imaging. The first part of my thesis was oriented to the studies of SiPM physics parameters as a function of temperature. Particularly, recent KETEK devices (year 2015) with different technological characteristics like p/n and n/p junctions, with and without trench technology, and different widths of epitaxial layer were studied in the temperature range from 308.15 K (+35°C) down to 238.15 K (-35°C). In addition, the Hamamatsu devices from 2011 production run as well as new devices from 2015 year, with improved technological characteristics inducing a reduced noise, were investigated in a wider temperature range from 318.15 K (+45°C) down to 98.15 K (-175°C). For these purposes, I participated to the design, installation, commissioning and calibration of a cryogenic experimental setup dedicated to electrical, optical and temperature studies of SiPM devices. Also, I have developed an automatic analysis procedure able to handle in a short time an impressive quantity of experimental data (i.e. tens of Gb/device) and to give a precise and fast information on main SiPM parameters and their temperature dependence. I have also developed a physical modeldescribing the DC I-V curves of SiPM detectors at different temperatures. The proposed model fits well the shape of IV curve in a very large currents range from 10⁻¹² A up to 10⁻⁵ A over the full working range of various devices. Consequently, the IV model can be used as a simple and fast method for determination of SiPM parameters like breakdown voltage VBD, the shape of Geiger triggering probability PGeiger as a function of Vbias as well as the Vbias working range. The comparison of these parameters with those calculated from AC measurements and analyzed by the automatic procedure showed a good agreement. The second part of my thesis was oriented to the study of SiPM devices and their physical parameters required to build a prototype of betasensitive intracerebral probe. Such probe is dedicated to measure the local concentration of radiolabeled molecules on awake and freely moving animal and to study new animal models of human disorders (neurodegenerative diseases, tumor growth, and neuropsychiatric disorders). It is composed of small size, low-noise SiPM device coupled to a scintillating fiber and readout by a dedicated miniaturized low-power consumption electronics. Three SiPM devices have been chosen as the most adapted for our application: two small KETEK devices of 0.5×0.5 mm² size (with and without optical trenches, specially developed by KETEK to fulfill our requirements) and a standard Hamamatsu device of 1.3×1.3 mm² size, all devices having 50 × 50 μm² μcell size. For each SiPM the gain G, dark count rate DCR and beta sensitivity were measured as a function of Vbias and temperature. The obtained results showed that the small field of view and newly developed structure of the KETEK devices allow a large decrease of the dark count rate DCR. However, this small field of view also leads to a reduced light collection due to the thickness of the epoxy protection resin on top of the SiPM and the acceptance angle of the fiber. Since the beta sensitivity represents a tradeoff between photon detection efficiency PDE and dark count rate DCR, KETEK SiPMs exhibit similar performances in comparison with the Hamamatsu device. Preliminary results demonstrate that the beta sensitivity of KETEK devices can be significantly improved by using focusing lens between the scintillating fiber and the SiPM or by reducing the thickness of its epoxy protection resin
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Duret, Damien. "Développement de sondes polymères fluorescentes à propriétés de ciblage améliorées pour des applications en imagerie cellulaire et en oncologie." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI060/document.
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Ce travail est axé sur l’amélioration des propriétés de biospécificité de sondes polymères fluorescentes, d’architectures contrôlées synthétisées par polymérisation RAFT, pour deux applications principales : le ciblage de tumeurs cancéreuses in vivo et le marquage de protéines pour des études in cellulo. Pour une imagerie ciblée de l’angiogénèse tumorale in vivo, des systèmes de ciblage multivalents à deux niveaux ont été élaborés en combinant à la fois i) des polymères bien contrôlés synthétisés par polymérisation RAFT et par le procédé PISA, ii) des clusters peptidiques tétravalents présentant une forte affinité pour les intégrines αvβ3 et iii) des fluorophores émettant dans le rouge lointain/proche-infrarouge pour un suivi in vitro et in vivo par microscopie optique. Deux types de sondes ont été synthétisés, des conjugués linéaires et des nanoparticules chevelues. La présentation multivalente du cluster peptidique permet d’augmenter considérablement l’affinité pour les intégrines αvβ3. Les premières évaluations biologiques indiquent une internalisation cellulaire des sondes polymères médiée par les clusters peptidiques ainsi qu’un marquage sélectif des cellules sur-exprimant les intégrines αVβ3. Pour le marquage de protéines, deux stratégies ont été explorées : le marquage de protéines natives par couplage covalent de sondes ω-fonctionnelles et le marquage de protéines recombinantes par des sondes porteuses d’un ligand spécifique. Pour la première stratégie, une fonction ester activé a été introduite en extrémité ω de sondes polymères par chimie thiol-ène pour marquer les résidus lysines des protéines natives. Cette approche a abouti à un poly-marquage difficile à contrôler mais offrant une brillance élevée. Pour la seconde stratégie, un groupement acide nitrilotriacétique (NTA) a été introduit en extrémité α des sondes polymères afin de marquer spécifiquement les protéines taguées Histidines. Cette approche a permis un marquage efficace de différentes protéines et permet de contrôler précisément le nombre de sondes par protéine ainsi que leur site de fixation sur la protéine. Finalement, suite à ces travaux, une nouvelle stratégie de synthèse de polymères séquencés par addition successive de monomères hétéro-bifonctionnels en utilisant des réactions chimiques très efficaces, sélectives et orthogonales a été proposée et validéeThis work is focused on improving the biospecificity properties of fluorescent polymer probes, with controlled architectures, for two main applications: the in vivo targeting of cancer tumors and the labeling of proteins for in cellulo studies. For a targeted imaging of tumor angiogenesis in vivo, targeting systems presenting two levels of multivalency were developed by combining both i) well-controlled polymers synthesized by RAFT polymerization and the PISA process, ii) peptide tetravalent clusters exhibiting a high affinity for the αvβ3 integrins and iii) fluorophores emitting in the far red / near-infrared for a monitoring in vitro and in vivo by optical microscopy. Two types of probes were synthesized, linear conjugates and hairy nanoparticles. Multivalent presentation of the peptide cluster induced a significant increase of the affinity for αvβ3 integrins. The first biological evaluations also indicated an efficient cellular internalization of polymer probes mediated by the peptide clusters and a selective labeling of cells over-expressing αvβ3 integrins. For protein labeling, two strategies were explored: the labeling of native proteins by covalent coupling of ω-functional polymer probes and the labeling of recombinant proteins by probes bearing a specific ligand at one chain-end. For the first strategy, an activated ester function was introduced at the ω-end of polymer probes by thiol-ene chemistry to label the lysine residues of native proteins. This approach resulted in a poly-labeling, difficult to control but providing highly bright bioconjugates. For the second strategy, a nitrilotriacetic acid group (NTA) was introduced at the α-end of polymers probes to specifically label Histidine tagged proteins. This approach enabled an efficient labeling of different proteins with a more precise control of the number of probes per protein and of the binding site. Finally, following this work, a new synthetic strategy of sequenced polymers by successive addition of hetero-bifunctional monomers using highly efficient, selective and orthogonal chemical reactions was proposed and validated
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Iga, Arthur Michael. "Development of novel flourescent nancocrystals ( Quantum dots) coated with a silica nanocomposite polymer for bio-medical application." Thesis, University College London (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505289.
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Mohammadkhani, Ghasem. "Evaluation of Wet Spinning of Fungal and Shellfish Chitosan for Medical Applications." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-25537.
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The aim of this project was to address the food waste problem, particularly bread waste, to some extent by producing monofilaments obtained from wet spinning of fungal hydrogel through the cultivation of Rhizopus delemar on bread waste. The project had two phases. Firstly, the possibility of production of chitosan fiber with wet spinning (using different acids) was evaluated, the process was optimized, and then applied to the production of fungal fiber. Regarding first stage of the project, adipic acid, a non-toxic solvent with two carboxyl groups, was used as acting physical crosslinker between the chitosan chains, resulting in improving properties of the monofilaments. Adipic acid performance was compared with conventional solvents, such as citric, lactic, and acetic acids. By injecting chitosan solutions into a coagulation bath (EtOH or NaOH 1M or EtOH-NaOH or H2SO4-EtOH), monofilaments were formed. Scanning electron microscopy showed that uniform chitosan monofilaments with smooth surface were formed using adipic and lactic acids. In general, fibers obtained from adipic acid displayed higher mechanical strength (Young’s modulus of 4.45 GPa and tensile strength of 147.9 MPa) than that of monofilaments produced using conventional solvents. Fiber dewatering with EtOH before drying led to greater fiber diameter and lower mechanical strength. As the second stage of this study, Rhizopus delemar was cultivated on bread waste in shake flasks and 1.3 M3 bioreactor. While different combinations of ground bread and K2HPO4 was used as the substrate for shake flask cultivations, white bread waste without K2HPO4 was utilized for scaling up the process, mostly due to the Glucosamine (GlcN) and N-acetyl-glucosamine (GlcNAc) content in the fungal cell wall. GlcN and GlcNA content obtained from ground bread was remarkably higher than that of obtained from combinations of ground bread and K2HPO4 as the substrate. Cultivation in 1.3 M3 bioreactor resulted in about 36 kg wet biomass with a mean of 14.88% dry weight, indicating 5.95 g biomass/L. The biomass yield of 0.15 g dry biomass/g dry bread was achieved. Alkali insoluble material (AIM) was obtained by alkali treatment of biomass. Fungal hydrogel was prepared by adding adipic and lactic acid to AIM, followed by grinding treatment. While hydrogels treated with lactic acid showed better spinnability and gelling ability, the one from adipic acid was not uniform to be wet spun. Considering hydrogels treated with lactic acid, the optimum grinding cycle for more spinnable hydrogel was 6 negative cycles, contributing to the fibers with the tensile strength of around 82 MPa. Such fibers showed antibacterial property against Escherichia coli, making them as a good option for suture applications. However, further in vitro and in vivo trials are essential to test the fungal fiber for such applications.
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Smejkalová, Kateřina. "Charakterizace a aplikace mikrovlnného plazmatu pro hojení ran." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-414123.
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The aim of the Master thesis is the investigation of the influence of microwave discharge for skin wound healing. Microwave discharge used for this work was argon microwave plasma generated by the surface wave and direct vortex torch. The theoretical part is focused on basic information about plasma and processes that occur in plasma discharge under specific conditions. Plasma generates various active particles such as hydroxyl radicals, nitric oxide radicals, excited nitrogen molecules, atomic nitrogen, argon and oxygen. All of these particles together with plasma generated photons are usable in biomedical applications and summary of them is shown in the theoretical part. The experimental part is focused on the comparison of torch discharge and microwave plasma generated surface wave in skin wound healing. The model wounds on laboratory mousses were treated by plasma and wound healing was examined during 3 weeks after the plasma treatment. Both plasma systems showed healing acceleration. Application of torch discharge was proved to be the most effective method in the healing of skin defects. Additionally, determination of active particles was taken by optical emission spectroscopy. Based on these measurements, plasma parameters were determined: electron temparutare, rotational and vibrational temperatures. To determine role of different plasma active species, the treatment of indigo coloured artificial skin model was treated under various conditions by both plasma systems. Results show that the direct interaction between plasma particles is the main effect, role of radiation, only, is more or less negligible. Finally, the plasma vortex system was visualized using fast camera at selected powers and gas flows.
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Åkerlund, Elin. "Development of polymer based composite filaments for 3D printing." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388554.
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The relatively new and still growing field of 3D-printing has opened up the possibilities to manufacture patient-specific medical devices with high geometrical accuracy in a precise and quick manner. Additionally, biocompatible materials are a demand for all medical applications while biodegradability is of importance when developing scaffolds for tissue growth for instance. With respect to this, this project consisted of developing biocompatible and bioresorbable polymer blend and composite filaments, for fused deposition modeling (FDM) printing. Poly(lactic acid) (PLA) and polycaprolactone (PCL) were used as supporting polymer matrix while hydroxyapatite (HA), a calcium phosphate with similar chemical composition to the mineral phase of human bone, was added to the composites to enhance the biological activity. PLA and PCL content was varied between 90–70 wt% and 10-30 wt%, respectively, while the HA content was 15 wt% in all composites. All materials were characterized in terms of mechanical properties, thermal stability, chemical composition and morphology. An accelerated degradation study of the materials was also executed in order to investigate the degradation behavior as well as the impact of the degradation on the above mentioned properties. The results showed that all processed materials exhibited higher mechanical properties compared to the human trabecular bone, even after degradation with a mass loss of around 30% for the polymer blends and 60% for the composites. It was also apparent that the mineral accelerated the polymer degradation significantly, which can be advantageous for injuries with faster healing time, requiring only support for a shorter time period.
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Choudhury, Samir. "Radiation Modeling for Bio-Medical Applications." Thesis, 2009. http://ethesis.nitrkl.ac.in/264/1/Radiation_Modeling_for_Bio-Medical_Applications.doc.
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Thermal radiation is important in many applications, and its analysis is difficult in the presence of a participating medium. In traditional engineering studies, the transient term of the radiative transfer equation (RTE) can be neglected. The assumption does not lead to important errors since the temporal variations of the observables e.g. temperature are slow as compared to the time of light of a photon. However in many new applications in different fields the transient effect must be considered in the RTE, like it has a great usability in the field of Bio-medical (applications like optical tomography, detection of scar tissues and many more all of which is interaction of LASER with the participating medium, tissue). In the transient phase, the reflected and the transmitted signals have temporal signatures that persist for a time period greater than the duration of the source pulse. This could be a source of information about the properties inside the medium. Hence sufficiently accurate solution methods are required.
In the last few years, the finite volume method (FVM) and discrete transfer method has emerged as one of the most attractive methods for modeling steady and transient state radiative transfer.
The present research work deals with the analysis of steady and transient radiative transfer in two dimensional square enclosure using FVM and analysis of steady and transient RTE with one boundary subjected to single short pulse irradiation.
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Goud, Siva Charan Bache. "Edible Battery Design for Bio-Medical applications." Thesis, 2022. https://etd.iisc.ac.in/handle/2005/5969.
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This thesis is focused on the development of digestible electronics for healthcare.
The vision is the development of an edible pill that performs diagnosis inside the
body. Any such edible device needs an energy source made of non-toxic materials.
This thesis discusses the development of such an energy source.
The main idea is based on using a galvanic cell. This thesis constraints itself in
exploring Zn/Cu based cells using lemon extract-pectin blend extracts. Cells based
on a solid electrolyte, gel based electrolyte and a liquid electrolyte contained in a
hardened shell of isomalt are discussed. The load characterisitcs of the cells show
promise to deliver energy to power the device for 100 s. Furthermore, the thesis
details how the cells could be used as a sensor to sense the pH.
To summarize, the thesis develops the means and methods to develop a compact
edible power source.
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Te-Tsung, Chen, and 陳德聰. "Optimal control for applications of bio-medical technology." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/50282414701853423881.
Full textAbstract:
碩士國立成功大學
造船及船舶機械工程學系碩博士班
91
An optimal control algorithm for cryoperservation of cells utilizing the conjugate gradient method (CGM) of minimization is applied successfully in the present study in determining the strength of optimal laser heating based on the desired temperature distributions of the cell. The validity of this optimal control analysis is examined by using the numerical experiments. Three different heating times are given and the corresponding optimal control heat fluxes are to be determined. Results show that the optimal boundary heat fluxes can be obtained with any arbitrary initial guesses within a very short CPU time on a Pentium III-600 MHz PC. Finally a 2-D enthalpy method is applied to the phase change problem to calculate the cooling rate of the cell.
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"Integrated polymer based microfluidic system for bio-medical applications." Thesis, 2005. http://library.cuhk.edu.hk/record=b6074022.
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Over the past years, microfluidic systems have been rapidly developed from early single channel devices to current complex integrated analysis systems. The development in microfluidics has led to the realization of miniaturized applications in biomedical or chemical analysis. High throughput and automated microfluidic systems have made it possible to achieve biomedical or chemical instruments with new levels of performance and capability. However, because of the requirement of biomedical systems, disposed and optically transparent materials, high aspect ratio structures, and complicated fluidic connection are desirable. Conventional silicon microfabrication process may not overcome these limitations. In this work, micro molding replication technique is proposed as a low-cost polymer microfabrication technique. Based on this technique, four polymer based microfluidic devices, which are vortex micropump, discretized micromixer, carbon nanotube based flow sensor, and Surface Plasmon Resonance (SPR) imaging biosensor have been designed, fabricated and demonstrated. According to different applications, these individual devices can be integrated into an automated microfluidic analysis system to sense, regenerate, and deliver fluid volumes in the order of micro-liters. This miniaturized and integrated system can provide a high throughput, increased resolution, and better controllable environment. Using the integrated and automated microfluidic system, two biomedical experiments, including monitoring of bovine serum albumin (BSA) binding reaction with BSA antibodies, and cell adhesion properties under the influence of trypsin, have been conducted.Lei Kin Fong Thomas.
"August 2005."
Adviser: Wen J. Li.
Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 4065.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (p. 88-98).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract in English and Chinese.
School code: 1307.
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Pang, Wen-Yi, and 龐文頤. "Low Power Analog Signal Processor for Bio-Medical Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/99398954455507336798.
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碩士國立臺灣大學
電子工程學研究所
97
The application of VLSI technology in bio-medical instrumentation enables the emerging of the bio-MEMS and wireless technologies. By combining these technologies, personal remote sensing has become a popular research area. It applies an implantable bio-medical circuit for neural stimulation and uses RF signal to transmit recorded physiological signals. In such implanted bio-medical circuits, low power operation is very important because the heat spread caused by the implanted circuit will increase local temperature which may damage organs and neurons. This thesis presents a signal processor with area-efficient DC offset cancellation. For this processor, this work designs the building blocks of a low power 10-bit successive-approximation-register analog-to-digital converter (SAR ADC) and a low power decimation filter for bio-medical applications. In the 10-bit SAR ADC, an energy-saving capacitor array and a splitting comparator architecture is proposed to achieve low power consumption. The average switching energy of the capacitor array can be reduced by 68% compared to a conventional architecture. The splitting comparator consists of two gain paths, through which power saving for an A/D conversion is achieved by selecting the appropriate comparison path and disabling the unused path. The measured signal-to-noise-and-distortion ratio of the ADC is 58.4 dB at 500KS/s sampling rate with power consumption of 42μW from a 1-V supply. The ADC is fabricated in a 0.18-μm CMOS technology. A low-power decimation filter for portable electrocardiogram (ECG) monitoring applications is also presented. This decimation filter consists of two parts: front-end and back-end. The font-end filters noise to regain ECG signal while the back-end computes the direct current (DC) offset caused by the local oscillator (LO) leakage and subtracts it from the input. This makes the ECG signal stays within the allowable ADC input range. In addition, selecting the right decimation factors gives the most efficient design in terms of storage requirements and the number of multiplications per second (MPS). Finally, the functionality of the decimation filter is tested and verified with an Altera Stradix EP1S80 FPGA board and Tektronix TLA 715.
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Yu, Yi-Long, and 尤乙龍. "Low Power Analog to Digital Converter for Bio-Medical Applications." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/33330097943946815260.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
100
This thesis researches an energy-efficient analog to digital converter (ADC) for bio-medical applications, and proposes a master-slave digital to analog converter (M-S DAC) technique implemented in a successive approximation register analog (SAR) ADC chip fabricated in 180nm CMOS. The function of energy-reduction is demonstrated by the measurements of the chip. The M-S DAC technique using an additional master DAC (MDAC) with extra area of 5% in capacitor array can prevent energy from waste in vain, which is caused by the repeatedly charge and discharge in the same capacitor of conventional capacitor array, particularly in larger bits. The sequences of M-S DAC are sampling, MDAC cycling, bit transferring, slave DAC (SDAC) cycling. The optimum number of bits and energy dis-sipation in the capacitor array is analyzed and identified by the simulation and meas-urements. The prototype SAR ADC using the M-S DAC has the resolution of 10-bit, sam-pling rate at 500KS per second with supply voltage of 1V which is adopted by bio-applications in common. The reduction ratio of energy dissipation in capacitor array is 93% in this work within the mismatch constraint and the core area is 0.15 mm2 with the area-reduction of 75% in capacitor array compared with conventional array. This prototype achieves the signal-to-noise-and-distortion-ratio of 59.2dB in equivalent to effective number of bits of 9.6-bit in measurement. The power consumption significantly reduces by M-S DAC technique. The total power is 28μW and it reaches the FoM 77fJ/Conversion-step. Conclusively, this thesis provides a technique for capacitor array to reduce energy dissipation, and demonstrated the function of the technique by a fabri-cated chip.
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Chang, Ying-Da, and 張英達. "Low Power VCO-Based ΔƩ Modulator for Portable Bio-Medical Applications." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/37263591388686510815.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
101
Aging population and growing chronic patients are becoming urgent things to be resolved. Patient-centered medical home is a solution to mitigate these impacts by the concepts of self-monitor, self-control, self-diagnosis, and self-treatment. In order to achieve these goals, convenient, flexible and portable circuit systems for bio-medical applications are researched popularly especially in the analog-to-digital converters (ADCs). Because ADCs are bridges of communication between the digital signal and the weak analog signal form nature world. This thesis presents a nano-Watt and 0.06mm2-ranked VCO-based delta-sigma modulator with sufficient resolution for portable bio-medical applications to achieve circuit requirements of convenient and flexible. In the VCO-based delta-sigma modulator, the voltage scaling technique and center frequency self-calibration technique are proposed to achieve near 10 effective-number-of-bits (ENOB) without any additional amplifiers. In addition, the optimum supply voltage of the ring VCO is interpreted. This chip is fabricated in a 0.18μm CMOS process. The VCO-based delta-sigma modulator and center frequency self-calibration technique occupy an active area of 0.032mm2 and 0.028mm2 respectively and separately consume 379nW and 303nW. The self-calibration technique takes 120 sampling periods to correct the center frequency of the ring VCO from about 1.795MHz to 1.751MHz with -101.6dBc/Hz phase noise at 100kHz, which is within the range of 10 ENOB requirement. With an 885.01Hz 0.7Vpp-diff input signal, the modulator achieves peak signal-to-noise ratio (SNR) of 59.8dB and signal-to-noise plus distortion ratio (SNDR) of 58.5dB over bandwidth of 2kHz.
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Liu, Hui-Hsien, and 劉慧賢. "Design of 400 MHz RF Receivers for Bio-medical Implantable Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/55365882390617743455.
Full textAbstract:
碩士臺灣大學
電子工程學研究所
98
In this work, two low-power receivers operating in the 400 MHz frequency band are designed for bio-medical implantable applications. One of the receivers is for Gaussian Frequency Shift Keying (GFSK) demodulation and will be discussed in chapter 2 and chapter 3. The other one is for On-Off Keying (OOK) demodulation and will be discussed in chapter 4 and chapter 5. The proposed GFSK receiver is a frequency digitizer adopting the structure of a continuous time delta-sigma PLL. The information of a GFSK signal is stored in its frequency; therefore, it is much more robust against channel noise than signals using other modulation methods. The proposed receiver architecture combines the demodulation and digitization process of GFSK modulated signals. The operation is done directly at a high carrier frequency of 400 MHz. The proposed design is fabricated in a 0.18-μm CMOS technology. It consumes 15.45 mW and achieves a data rate of 2 Mbps. The proposed OOK receiver adopts the architecture of a super-regenerative receiver. This architecture is simple and consumes low power. Because of PVT variations, a frequency calibration circuit is needed to adjust the oscillator center frequency to the designed band. Although this can be done by a phase-locked loop, its locking time is too long and consumes much power. In this work, a fast digital frequency calibration circuit is proposed and the maximum tuning time is just 2.7 μs. The receiver is capable of achieving a maximum data rate of 1 Mbps. The proposed super-regenerative receiver, fabricated in TSMC 0.18-μm CMOS process, consumes only 2.2 mW.
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Yi-Huei, Chen, and 陳宜輝. "Design and Implementation of RF Front-Ends for Bio-Medical Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/dh5b5f.
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碩士國立臺北科技大學
電子工程系研究所
103
This paper discuss the radar which detects the Doppler shift caused by breathe and heartbeats. By the detection theory, we can design the Doppler radar for vital-sign sensing. The architecture of conventional transceiver include oscillator, power amplifier, and low noise amplifier, the quality of detection signals are decided by the performance of transceiver. Compare to the traditional architectures of vital-sign sensors, the proposed vital-sign sensors are based on injection-locked oscillator. The advantages of this sensors are less complex and no need of low noise amplifier at receiver. To prevent the null detection points, the IQ demodulators are used in this design. In this paper, the components of transceivers are design and implement on FR4, include Clapp oscillator based on BJT, circulators, IQ demodulator, and baseband active band pass filters. Test the sensor can sense the frequencies of breathe and hearts beat away from subjects about 80 cm with an error rate 4 % and IQ demodulator can solve the null detection point. This thesis also complete a fully integrated vital-sign sensor by using TSMC 0.18μm CMOS technology, include a VCO with injection port and an IQ demodulator made by mixers and RC phase shifter. To improve the ability of sensor, the baseband active band pass filter are required.
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Loumes, Laurence. "Multilayer impedance pump: a bio-inspired valveless pump with medical applications." Thesis, 2007. https://thesis.library.caltech.edu/65/12/L.Loumes-Thesis-All.pdf.
Full textAbstract:
This thesis introduces the concept of multilayer impedance pump, a novel pumping mechanism inspired from the embryonic heart structure.
The multilayer impedance pump is a composite two-layer fluid-filled elastic tube featuring a thick, gelatin-like internal layer similar in nature to the embryonic cardiac jelly, and that is used to amplify longitudinal elastic waves. Pumping is based on the impedance pumping mechanism. Elastic waves are generated upon small external periodic compressions of the elastic tube. They propagate along the tube’s walls, reflect at the tube’s extremities and drive the flow in a preferential direction. This fully coupled fluid-structure interaction problem is solved for the flow and the structure using the finite element method over a relevant range of frequencies of excitation. Results show that the two-layer configuration can be an efficient wave propagation combination, and that it allows the pump to produce significant flow for small excitations. The multilayer impedance pump is a complex system in which flow and structure exhibit a resonant behavior. At resonance, a constructive elastic wave interaction coupled with a most efficient energy transmission between the elastic walls and the fluid is responsible for the maximum exit flow. The pump efficiency reaches its highest at resonance, highlighting furthermore the concept of resonance pumping.
Using the proposed multilayer impedance pump model, we are able to bring an additional proof on the impedance nature of the embryonic heart by comparing a peristaltic and an impedance multilayer pump both excited in similar fashion to the one observed in the embryonic heart.
The gelatin layer that models the embryonic cardiac jelly occupies most of the tube walls and is essential to the propagation of elastic waves. A comparison between the exact same impedance pump with and without the additional gelatin layer sheds light on the dynamic role of the cardiac jelly in the embryonic heart and on nature's optimized design.
Finally, several biomedical applications of multilayer impedance pumping are presented. A physiologically correct model of aorta is proposed to test the pump as an implantable cardiovascular assist device.
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Liu, Yao-Hong, and 劉耀鴻. "Design of 400-MHz Energy-Efficient RF Transceivers for Bio-medical Implantable Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/25064663728731215172.
Full textAbstract:
博士國立臺灣大學
電子工程學研究所
97
A low-power radio transceiver designed for implantable medical applications is presented in this dissertation. These transceivers operate at around 400-MHz band and utilize different modulation schemes and data rate between downlink and uplink. A low-data-rate ASK RX is presented for downlink reception; while high-data-rate GFSK, OQPSK and HS-OQPSK TXs are demonstrated for uplink transmission. Chapter 1 and Chapter 2 will firstly discuss the targeted medical applications as well as the design requirements for the medical transceivers. In Chapter 3, several low-power transceiver architectures are introduced, including a super-regenerative receiver, mixer-based and PLL-base direct-modulation transmitters. Downlink reception adopted a super-regenerative ASK RX with a proposed Delta-Sigma Pulse-Width-Digitizer (DS-PWD) will be presented in Chapter 4. The DS-PWD can be considered as a pulse-width-domain counterpart of a conventional Delta-Sigma modulator which can suppress quantization jitter by 22 dB and achieve a pulse-width detection resolution of 0.23 ns. The whole receiver consumes 900 uW. With a 156-kbps data rate, the RX achieves -78-dBm sensitivity. Chapter 5 and Chapter 6 will then present a MUX-based dual-mode uplink TX. First, a Sigma-Delta Phase Rotator (SD-PR) designed for G/FSK uplink transmission is discussed in Chapter 4. By properly combining the multi-phase signals from the PLL output, the SD-PR can effectively synthesize frequency modulation signals with fine-resolution frequencies. The proposed G/FSK TX consumes 9 mW and delivers -11-dBm output power. With a maximum data rate of 6-Mbps, the G/FSK TX achieves 1.5-nJ/bit energy efficiency. Chapter 6 presents an energy-efficient OQPSK TX which can also be implemented with the SD-PR proposed in Chapter 5, by directly selecting one of the quadrature phases through the Phase MUX. The whole OQPSK TX dissipates 3.5 mW. With a maximum data rate of 17.5 Mbps, the OQPSK TX achieves an energy efficiency of 200 pJ/bit and is capable of delivering an output power up to -8 dBm. In order to further improve the spectral efficiency of previous MUX-based OQPSK transmitter, Chapter 7 proposed a FIR-embedded Phase-MUX which allows to half-sine shape the OQPSK modulation; thus reducing the side-lobe energy of OQPSK modulation. The proposed HS-OQPSK TX (without PLL) consumes 1.4 mW and achieves 25-Mbps data rate. Finally, Chapter 8 will summarize and conclude this dissertation.
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Chang, You-Kuang, and 張祐匡. "Low Power Analog-to-Digital Converter and Super-Regenerative Receiver for Bio-Medical Applications." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/61131784989171681706.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
95
As the emerging of the bio-MEMS and wireless technology, the implantable bio-medical system becomes a popular research topic. The primary challenge is how to reduce power consumption of the system. Low power operation is essential for any implanted bio-medical system as the heat spread by the circuits will increase local temperature which may damage our organs and neurons. This thesis presents a low power successive-approximation-register analog-to-digital converter (SAR ADC) and a low power super-regenerative receiver for bio-medical applications. In this 8-bit SAR ADC, an energy-saving switching sequence technique is proposed to achieve low power consumption. The average switching energy of the capacitor array can be reduced by 56% compared to a conventional switching sequence. The measured signal-to-noise-and-distortion ratios of the ADC is 46.92 dB at 500KS/s sampling rate with an ultra-low power consumption of only 7.75-μW from a 1-V supply voltage. The ADC is fabricated in a 0.18-μm CMOS technology. A low-power super-regenerative receiver for 915MHz ISM band is also presented. The super-regenerative oscillator which is the core of the receiver is quenched by a 5-bit DAC and therefore the selectivity of the receiver can be controlled precisely. Furthermore, operating the MOS in sub-threshold region lowers the power consumption of the receiver. The simulation results show that the receiver consumes 0.8mW for a sensitivity of -90dBm and data rate of 1Mbps at 1-V supply voltage in a 0.18-μm CMOS technology.
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Yu, Chih-Sheng, and 余志盛. "Study of Programming Sine Wave and Square Wave for Applications of Bio-medical Technology." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/33936150510826946656.
Full textAbstract:
碩士國立暨南國際大學
光電科技碩士學位學程在職專班
102
Bio-medical technology has been closely linked with human life and plays a very important role in this paper is to propose a low-cost research and the application of a strong framework for microcontroller applications in biomedical science and technology can be applied to human cells impedance measurement. If the application due to high-voltage perforation technique in human cells does not reverse seasonal need with pulse width modulation (PWM) to produce extremely short pulse duration of the pulse wave, avoid excessive damage to other normal cells. In this study, with the use of micro-processing circuit may generate a pulse duration of about 20 ns ~ 135 ns pulse is very short, which can effectively be applied to cause electroporation reduce damage to normal cells of human time. In this paper, another study using a non-invasive way to measure the impedance of human cells, and made a two-dimensional grayscale graphical output, to quickly distinguish between normal cells and diseased cells purposes. This study uses micro-processing circuit can generate a sine wave with a constant current source, and through multiple sets of resistors and capacitors in parallel simulation of normal human cells and diseased cells impedance, and then do the sample measured data via computer to calculate the impedance of human cells, and finally the use of virtual instrumentation program will be divided into a gray area of human cells and white, gray part represents the high impedance of normal human cells, the white part of the body represents a low impedance diseased cells, with gray and white gray scale can make multiple sets of two-dimensional map like and to determine differences between normal cells and diseased cells.
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Cai, Sian-Jhu, and 蔡弦助. "Temperature desorption and spectroscopic studies of surface functionalized nanodiamond and their bio-medical applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/52485406466361345620.
Full textAbstract:
碩士國立東華大學
應用物理研究所
97
In recent years, more and more nanomaterial have been applied in bio and medical sciences. Nanodiamond is one of the most promising materials for bio applications, because it is proved to be more biocompatible such as in biological system than other bio – marker materials, such as carbon nano tubes and quantum dots. Compared with carbon nano tubes and quantum dots, nanodiamond is a promising nanomatreial as a bio marker to identify bio interactions. In this work, we used Fourier transform infrared spectroscopy (FTIR) and Temperature Desorption system to analyze the functional groups properties on nanodiamond with different particles sizes, varying temperatures and PH values of the suspensions. The analysis results provide necessary information for nanodiamond’s bio – medical application. The interaction of carboxylated/oxidized nanodiamond with living cells (A549, lung cancer cells and HFL1, lung fibroblasts). It’s penetration into cells is studied using optical and spectroscopic properties of nanodiamond. The luminescence of nanodiamond inside the cells can be excited and observed. The nanodiamond’s intrinsic luminescences from N-V centers are suitable for bio-labeling. For this study nanodiamond or nanodiamond conjugated with growth hormone suspensions was admixed to the cell culture, to interact with normal lung fibroblast cells and lung cancer cells. Via Confocal Raman Spectroscopy and Confocal fluorescence Spectroscopy the interaction of cells and nanodiamond or nanodiamond conjugated with growth hormone was observed. The interaction of nanodiamond with cancer cells differs from that with normal cells. The surface properties of nanodiamond are convenient for bio-molecules attaching, optical and spectroscopic properties, which make nanodiamond detectable upon interaction with cells. Nanodiamond penetration into the cells, together with nanodiamond’s non-cytotoxicity demonstrates that nanodiamond has great potential in bio and medical applications.
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Chang, You-Kuang. "Low Power Analog-to-Digital Converter and Super-Regenerative Receiver for Bio-Medical Applications." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2307200715004200.
Full text
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Wang, Chien-Liang, and 王建良. "The development and study of polymeric thin-film electrophoresis microchip for bio-medical applications." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/03267490779334963643.
Full textAbstract:
碩士中山醫學大學
毒理學研究所
90
Abstract Over the last years, the miniaturization of biochemical analytical tools has become an expanding field. Indeed, such devices allow decreasing both the consumption of analytes and the duration of analyses. This is particular important for the life science developments such as genetic analysis and drug discovery. Comparing to traditional slab gel electrophoresis, capillary electrophoretic methods show an advantage of fast analysis, low sample consumption, high analyzing efficiency, and automation. Recently the developments of chip-based separation devices are increased speed and reliability at reduced sample consumption and cost, particularly microchip electrophoresis. In this study, a polymeric thin-film microchip for electrophoresis and mass spectrometry was developed. The micro channel is fabricated by micro blade method in PE/PET films, and then sealed by lamination. Because the fabrication without considering the depth of micro channel, it reduces manufacture process from the 3-dimention to 2-dimention in CE chip fabrication. By this way, we take advantage of simply fabrication process and less fabricating time and cost. The characterization of the polymeric thin-film electrophoresis microchip was tested and nanoESI chip was developed according to easy cutting, and sealing of the thin film. Two new types of microchip: four layers microchip and arched microchip were designed for better sample injection. The merits and limitations of those approaches are discussed. To summarize, depending on simplification and rapidity; we looking forward to fabricate high efficiency analytical tools with less time and cost. Therefore, there is also potential for development of disposable diagnostic systems for biomedical applications.
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Huang, Guan-Ruey, and 黃冠瑞. "Design and Fabrication of High-throughput Microfluidic Chips and Their Applications on Bio-medical Analysis." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/44324311128370381826.
Full textAbstract:
碩士國立成功大學
工程科學系
89
Design and fabrication of microfluidic devices on quartz and polymethylmethacrylate (PMMA) substrates for analytical chemistry and biomedical-related applications using micromachining techniques and MEMS (Micro-Electro-Mechanical-Systems) technology are described. Four microfluidic devices are demonstrated in this study and described as follows. (1)Micro-capillary electrophoresis chip: A micro capillary electrophoresis (m-CE) device for DNA separation and detection is demonstrated. It is fabricated on quartz and PMMA substrates. The capability of the fabricated chip for electrophoretic injection and separation is characterized via the analysis of DNA fragments fX-174-RF Hae III digest. Experimental results indicate that all of the 11 DNA fragments of the size marker could be identified in less than 2 minutes (2)Flow-through sampling microchip: A novel microfluidic chip for continuous sample injection has been developed. The capability of the microchip for continuous mode of sample introduction is demonstrated successfully. (3)Micromachined pre-focused 1×N flow switch for continuous sample injection: The micro flow switch integrates two important microfluidic phenomena, including hydrodynamic focusing and valveless flow switching on a planar structure. Experimental data indicate that pre-focused micro flow switch could guide sample flow to a desired outlet port successfully. (4)Micromachined pre-focused M×N flow switches for continuous sample injection: Multiple samples could be pre-focused to narrow streams and then continuously injected into desired outlet-ports using this chip. The microfluidic chip could be used for high-throughput chemical analysis. In this study, a simple but reliable one-mask micromachining process is developed to fabricate the microfluidic devices. The image of microstructures is transferred from quartz master templates possessing the inverse image of the devices to plastic plates by using hot embossing methods. The micro channels on quartz master templates are formed by the combination of metal etch mask and wet chemical etching of a photomask blank. The micromachined quartz templates can be used repeatedly to replicate cheap and disposable plastic devices. Experimental data show that these four microfluidic devices can by applied for chemical analysis successfully.
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Sharath, U. "Fiber Bragg Grating Based Sensing Devices for Novel Applications in Bio-medical and Engineering Fields." Thesis, 2015. https://etd.iisc.ac.in/handle/2005/4556.
Full textAbstract:
Sensors have been an integral part of human life. Various sensor technologies have contributed in their own ways to fulfill specific requirements for aiding human beings. In this context, fiber optic sensors have several advantages such as availability of large number of components from communication industry, small footprint, easy fabrication, and immunity to Electro Magnetic Interference. In the category of fiber optic sensors, Fiber Bragg Gratings (FBGs) have been found to be very useful, because of their high sensitivity, multi-modal sensing ability, large operational bandwidth, and multiplexing capability.
An FBG is a periodic orthogonal perturbation of the refractive index along the longitudinal axis of the core of a single mode optical fiber. The periodic modulation of index of refraction is brought about by exploiting the photosensitivity of a germania- doped silica fiber upon exposure to UV light. FBGs, in the basic form, can sense strain and temperature. However, in recent years, several newer sensing applications of FBGs are being explored and the present thesis is an attempt in this direction.
In this thesis work, Fiber Bragg Grating sensor-based devices have been devised for newer applications in bio-medical and engineering fields. Basically, novel packaging methodologies for FBGs are designed and developed, which transduce the measured parameter to a secondary parameter that can be sensed by the FBG.
In the field of Cardiology, an FBG Pulse Recorder has been developed which has the ability to acquire the radial arterial pulse pressure waveform. It records the beat-to-beat pulse pressure along with the radial arterial diametrical variations. The FBG Pulse Recorder has been employed to measure the blood pressure in conjunction with a sphygmomanometer, using the unique signatures obtained in the radial arterial pulse pressure waveform. By the same methodology, radial arterial compliance, is evaluated. Also, using two FBG Pulse Recorders at the carotid and radial arterial sites the pulse transit time differential is measured which acts as an indicator of variation in systolic blood pressure and pulse wave velocity.
In the field of dentistry, a novel technique for real time dynamic measurement of the maximum individual bite force using Fiber Bragg Grating Bite Force Recorder has been proposed. The results obtained show that bite forces increase along the dental arch and are found to be higher in male than in female. Also, an in-vitro study utilizing the FBG temperature sensor has been carried out to measure the variation of temperature in the pulp chamber during light curing of composite materials.
In the field of seismology, a new methodology for real time dynamic monitoring of seismic vibrations, using a Fiber Bragg Grating Seismic Sensor has been proposed. The validation and field tests are carried out in comparison with a commercial seismometer. Further, the feasibility study for an elephant intrusion monitoring system employing the sensor developed has been put forth.
Furthermore, a displacement device has been devised which converts displacement into strain on a cantilever beam over which the FBG sensor is bonded with the aid of a pivoted arm. This arm provides the necessary mechanical amplification of the displacement by varying the pivot screw position, facilitating tunable sensitivity for the FBG displacement device. Also, the same device has been used for measurement of vibration and with enhanced sensitivity for surface profilometry with a resolution of 175nm.
To summarize, the present thesis demonstrates a comprehensive experimental study which bring out the utility of FBG sensors in variety of challenging applications.
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Chen, Chih-Lin, and 陳致霖. "Self-sampled All-MOS ASK Demodulator & Synchronous DAC with Self-calibration for Bio-medical Applications." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/28749964792914155682.
Full textAbstract:
碩士國立中山大學
電機工程學系研究所
98
This thesis includes two topics, which are a Self-sampled ALL-MOS ASK Demodulator and a Synchronous DAC with Self-calibration. An all-MOS ASK demodulator with a wide bandwidth for lower ISM band applications is presented in the first half of this thesis. The chip area is reduced without using any passive element. It is very compact to be integrated in an SOC (system-on-chip) for wireless biomedical applications, particularly in biomedical implants. Because of low area cost and low power consumption, the proposed design is also easily to be integrated in other mobile medical devices. The self-sampled loop with a MOS equivalent capacitor compensation mechanism enlarges the bandwidth, which is more than enough to be adopted in any application using lower ISM bands. To demonstrate this technique, an ASK demodulator prototype is implemented and measured using a TSMC 0.35 μm standard CMOS process. The second topic reveals a synchronous DAC with self-calibration. The main idea is to use a calibration circuit to overcome large error of output voltage caused by the variation of the unit capacitor. When DAC is not calibrated, INL is larger than 1.7 LSB. After calibrated, INL is improved to be smaller than 0.5 LSB. To demonstrate this technique, a DAC prototype is implemented and measured using a TSMC 0.18 μm standard CMOS process.
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Tsai, Yi-Lin, and 蔡宜霖. "Design of an RF Transceiver and a Two-channel Analog Front-end Amplifier for Bio-medical Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/69090915437457203832.
Full textAbstract:
博士國立臺灣大學
電子工程學研究所
104
Short-range wireless communication systems such as multichannel sensing/monitoring system and body area network (BAN) are increasingly popular in recent years because of the convenience. A bio-medical system-on-a-chip (SoC) is usually employed in such application scenarios. Due to limited battery power, an energy-efficient wireless transceiver is highly desirable to extend battery life. Therefore, conventional mixer-based transceivers using power hungry mixers and frequency synthesizers are not the ideal choice for this application. The first part of this dissertation reports a BPSK transmitter which adopts Phase-MUX and edge-combining techniques. Current reuse technique is employed in the power amplifier and the edge combiner, which achieves low-power target. Because high-frequency only exists in the PA path, the local oscillator can operate in the low-frequency band. Fabricated in TSMC 0.18-μm CMOS, the transmitter only consumes 0.33 mW at 20-Mbps data rate. The output power is -15 dBm with an EVM of 10%. The second part presents an energy-efficient 400-MHz D-BPSK receiver. The proposed D-BPSK receiver adopts injection locking technique to perform amplitude-to-phase conversion. This technique can demodulate the PSK modulated signal with envelope detector. The proposed receiver demodulates D-BPSK signal without using Costas loop and mixers, which leads to reduced power consumption and cost. The receiver is fabricated in TSMC 0.18-um CMOS technology. It consumes 1.77 mW with 0.9-V supply. The system sensitivity is -63 dBm. The energy efficiency is 177 pJ/bit with 10-Mbps input signal. In a bio-medical SoC, multiple channels occupy significant chip area, while their independence leads to gain mismatches. The third chip demonstrates a low-crosstalk and small-area two-channel instrumentation amplifier. The proposed orthogonal frequency chopping technique is utilized to separate tiny signals from two different channels. Additionally, these two different signals can be enlarged by the single shared operational amplifier. Low crosstalk means less interference between these two channels. Furthermore, the shared amplifier can reduce gain mismatch between these two channels. Fabricated in TSMC 0.35-um CMOS, the two-channel instrumentation amplifier consumes 27 uA from a 3-V supply, achieving -83-dB crosstalk and 0.061-mm2 chip area.
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Mehar, Amit Kumar. "Development, Characterization of Mechanical Properties, Wear behaviour and Machining Analysis of Ceramic Composites for Bio-Medical Applications." Thesis, 2017. http://ethesis.nitrkl.ac.in/8718/1/2017_PhD_512ME1043_AKMehar.pdf.
Full textAbstract:
Ceramic composites incorporating synthetic hydroxyapatite (HAp) particulate and thermoplastic polymer matrices are finding wide spread applications in bio-medical field. The fractured or damaged bone can be repaired or replaced by artificial bone materials. HAp has been tested many times as an artificial bone, especially as augmentation material in surgery work or as a coating material on bio-inert implants materials. It has shown excellent biocompatibility and bonding characteristics. Many implant materials used for last three decades are basically metals, alloys, ceramics and polymers etc. Most metals and ceramics are much stiffer than bone tissue resulting in mechanical mismatch (i.e. “stress shielding”) between the implant and the adjacent bone tissue. Metals are too stiff and pose other biocompatibility problems whereas ceramics are too brittle but polymers are too flexible and weak to meet the mechanical strength. However, polymers are popular due to their low density, good mechanical strength and easy formability. Therefore, polymeric bone implants are widely used. HAp particulates are mixed with polymer matrix through a series of processing stages involving melt compounding, granulating and micro-injection moulding. HAp is a suitable ceramic material for hard tissue replacement. In the present work, HAp is synthesized by wet chemical precipitation route. The mechanical properties such as tensile, compressive, flexural, impact and hardness are assessed for the composites varying HAp volume percentage in polycarbonate (PC) and polysulfone (PSU) polymers. The wear resistance of composites in abrasion, erosion, sliding and fretting mode is assessed in dry environment. Adaptive neuro-fuzzy inference system (ANFIS) model is proposed for prediction of wear behaviour of composites. The effect of drilling parameters on surface integrity of internal holes made on composite is assessed to provide insight into machinability (i.e. drilling) aspects of composites. The aim of this study is to develop material that has similar mechanical properties to that of human bone in order to achieve mechanical compatibility in the body, examine the various mechanical properties of ceramic composites, assess the performance of the ceramic composites under different wear modes and evaluate the performance of the composites in drilling operation. The samples were characterized by x-ray diffraction (XRD), fourier transform infrared test (FTIR), and scanning electron microscopy (SEM). Two-body abrasion wear behaviour of the composite is evaluated using pin-on-disc friction and wear test rig (ASTM G99). The experiment is conducted using three different water proof silicon carbide (SiC) abrasive papers of 400, 600 and 1000 grit size. Taguchi’s L27 orthogonal array is used to evaluate the tribological property with four control variables such as HAp volume percentage, load applied, sliding speed and track radius, each at three levels. The highest abrasive wear loss is noticed in the specimens worn with 400 grit size SiC paper. Erosion wear of ceramic composites is performed on air jet erosion test rig (ASTM G76). In this study, dry silica sand (spherical) of different particle size of 300μm, 400μm and 500μm are used as erodent. Taguchi’s L27 design is used to evaluate the tribological property with three control variables such as pressure, HAp volume, and impingement angle, each at three levels. The higher erosive wear loss is noticed in the specimens worn with 500μm erodent particle size as compared to both 300μm and 400μm erodent particle size. The sliding wear test of ceramic composites is performed on ball on plate wear tester (ASTM G194). Taguchi’s L27 design is designed to evaluate the tribological properties with three control variables such as HAp volume percentage, load applied and sliding speed, each at three levels. The fretting wear test of ceramic composites is performed on high frequency reciprocating rig (HFRR) testing machine (ASTM D6079). Taguchi’s L27 orthogonal array is used to evaluate the tribological properties with three control variables such as HAp volume, load applied and frequency, each at three levels. Since drilling is used to join the composite material with adjacent bone tissue in orthopaedic surgery, it is important to study drilling performance of the composite. Experiments have been conducted on a CNC milling machine using Taguchi’s L27 design with four control variables such as HAp volume percentage, drilling speed, feed rate and drill bit diameter, each at three levels. The responses considered are circularity at entry and exit, torque and thrust force. The circularity at both entry and exit is measured using the ratio of minimum diameter (Dmin) to maximum diameter (Dmax) of the drilled hole. The torque and thrust force are measured using drill dynamometer.
Best parametric setting for simultaneous optimization of multiple performance measures such as circularity at entry, circularity at exit, torque and thrust in drilling operation is suggested using principal component analysis.
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Wu, Bi-Ru, and 吳璧儒. "Microcontroller Design for Wireless Sensor Network in Bio-Medical Application." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/92575747846835428564.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
98
The application of SOC is very wild in the modern society; SOC can condense the area of the whole system. And the concept of wireless sensor network can be used in the long-distance observation system, and the home-health care issue. In the bio-medical application, the immediately health reaction from sensors carried in people can transmit the warning to the LCC, and then inform the health institution do the immediately action as some dangerous situation. In other situation, the wireless sensor network can be used in the detection for environment, such as some toxic gas and some dangerous chemical compound. In this these, the design concept is built on wireless sensor network, and the application is based on the sensors we combined into our integrated circuits. In the SOC, we implement this chip by TSMC 2P4M 0.35um standard CMOS process, which we will describe in the Chapter3. This SOC include the analog circuit, including ASK transmitter, OOK receiver, Instrument Amplifier, SAR ADC Converter and Voltage Regulator, and the gas sensor and temperature sensor. And the digital circuit is ASIC microcontroller for the whole system power and state transition control. The wireless sensor network protocol is developed by Dr. Ming-Hui Jin and our lab. The ASIC include the UART, Switch Controller, the Real Time Timer, the FSM and the Power Controller. The operation frequency is usually used in 19.2 kHz for the baud rate to connect the computer. The programmable microcontroller use two SRAMs to be the program memory and the data memory, one is 2k word, the other is 256 words. The instruction set is referred to the PIC microcontroller developed by Microchip. There are total 35 instructions and the program bus is 14-bit width and the data bus is 8-bit width. The general purpose I/O amounts are 13The programmable microcontroller include two UART, one for RX the other for TX, the watch dog, 3 timers, 8-level stack, and the interrupts of 8 source. The operation frequency is usually used in 4MHz.
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黃富翔. "The Application of Image Processing Techniques in Bio-Medical Detection." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/63340330709486169440.
Full textAbstract:
碩士國立中興大學
機械工程學系
91
In this thesis, new approaches of the computer vision techniques such as the optimal threshold, the auto focusing, the edge detection, and the image expansion are investigated. For the optimal threshold, the piecewise searching method that detects the threshold according to the histogram of the gray-level distribution is adopted. Experimental results show that the misjudge problems of the conventional methods is improved. It is also found that the worse the out-of focus is, the lower the optimal threshold is. This physical phenomenon is adopted to develop the new auto focusing method. Less complexity is the main advantage of the proposed auto focusing scheme. For better edge detection, we use the Lagrange polynomials to build a 2D Lagrange mask such that the required computation time is reduced and the subpixel edge can be directly estimated. The 2D Lagrange edge detection method along with the bipolar sigmoid function is then used to modify the expended edge such that the obscure expansion problem is decreased. To verify the performance of these new approaches, an auto focusing platform which consists of a linear slider and a step motor, a high resolution couple charged device (CCD), and an image processing software that is written in Borland C++ Builder, are brought together to build a complete image inspection system. The image processing tasks of the cell culture in tissue engineering demonstrate that the proposed image inspection system can be successfully applied to the biomedical analysis problems.
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Hsu, Sheng-Ruei, and 許升睿. "The Design of Analog-to-Digital Converter for Bio-Medical Application." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54963105460847292099.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
99
Since the life of human beings has been extended and social structure changed, biomedical application area has been fast developed and becomes a vital issue. Electrical engineers have turned their attention from consumer products to biomedical area. In order to follow this trend, we design ADCs that are suitable for biomedical application. In this thesis, we have designed two ADCs. First, a sigma delta modulator is presented. Its structure is suitable for high-resolution application from the result of past references. We use TSMC CMOS 0.35um process. The structure is switch-capacitor second-order architecture. Target bandwidth is 22.05KHz and have sampling rate 2,56MHz, that means we have OSR of 56. Under 3-V power supply condition, the maximum SNDR is 49dB, which is about 7.8 ENOB, and achieving 54dB dynamic range. Total area is 0.98x0.68mm2 and power consumption is 3mW. The second ADC is successive approximation ADC, the property of this circuit is low power consumption. This circuit is fabricated in TSMC 0.18um process and operates under 1-V power supply in order to save power. The target resolution is 10-bit. We use integer capacitor bridge to save chip area and maintain good capacitor mismatch. Our sampling frequency is 400KHz. Under Nyquist rate operation, maximum SNDR is 49.3dB, which is about 7.9 ENOB. Static testing performances INL is 2/-1.9 LSB and DNL is 1/-0.9 LSB. Power consumption is 9.5uW, FOM is 99fJ/conv., which is competitive among references.
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Yen, Chih-Jen, and 顏志仁. "Analog Integrated Circuit Design for Bio-Signal Measurement and Medical System Application." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/58909975997208127511.
Full textAbstract:
碩士中原大學
電機工程學系
87
The objective of this dissertation is to design and implement the analog integrated circuit chips for the wireless bio-signal transmission system. By the integrating method, it can achieve minimizing the occupied area, consuming little power, making the cost down and using conveniently. The analog integrated circuit chips have been used in the medical system application to process the physiological signal. The source of the signal is most coming from the electrocardiograpy (ECG). All these designed analog integrated circuits are based on a generic CMOS two-stage operational amplifier (op-amp). Design and characteristics of the CMOS two-stage op-amp has been presented in this dissertation. By using the op-amp, other analog circuits could be constructed, such as instrumentation amplifier, gain amplifier, switched-capacitor lowpass filter, and A/D converter. They are all integrated into chips. Before the fabrication of chips, these building blocks had simulated by HSPICE. The simulation results must meet the specifications. Then draw the circuit layout and simulate again (such as verification of DRC, LVS and LPE) until all the performance meet the specifications. The fabrication of chips uses the UMC 0.5μm double-poly double-metal CMOS technology. In order to identify the performance of these chips, The experimental on-board system constructed by using discrete commercial chips and designed chips have been verified in this research. The results showed that it meets the system specification. It is proved that by the integrating method, the occupied area can be minimized, and the expense of the system can also be reduced. Also, it is convenient to use.
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Lin, Pei-Ying, and 林佩瑩. "The Application of a Distributed Search Engine on Bio-medical Literature Analysis." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/95671679064488084740.
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碩士元智大學
資訊管理學系
90
In recent years, more and more biomedical-related information is available electronically due to the wide spreading of Internet and Web services. Mining valuable biomedical information from the literature has become an important issue. In the era of knowledge economy, in order to make the most value out of the information efficiently, it is important to apply the emerging information technologies to improve information overloading problem while searching information from the Internet. In this study, two search servers are proposed and implemented. The first one is a “Keypage Search Server” which finds similar documents from the Internet given a “keypage” with desired information. The second one is a “Genes-by-Disease Search Server” which finds related genes for a disease interested. The “matching-degree” module in SimNet architecture is applied in the keypage search server for measuring document similarity. Distributed computing mechanism is implemented in both servers to improve the computing performance as well as the network communication efficiency. Web-based architecture is used in this study to provide a user-friendly interface and ensure system compatibility.
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Chang, M. Z., and 張銘澤. "Performance Analysis and System Application of Thermoelectric coolers for Bio-medical Storage." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/01481756659024412481.
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碩士國立勤益科技大學
冷凍空調系
97
Abstract Thermoelectric cooler/heater has the advantage of being portable, simple, compact, low power consumption, noiseless, reliable, and environmentally benign, it is quite suitable for transporting and storage for bio-medical products (such as blood and platelet) which are very sensitive to temperature variation. In this study, the effort will be focused on the improvement of cooling performance for a thermoelectric blood cooler/heater and a portable storage bag. Performance tests were conducted to investigate the influence of cabinet temperature in the thermoelectric blood cooler. The experimental tests will also be performed to verify the optimized cooling capacity and heating performance, and to quantify the degree of improvement. The thermoelectric blood cooler/heater and storage bag have been developed successfully. The results revealed that it is accessible to cool down to 4℃ for 12V power input and heat up to 37℃ for 3~4V power input for the blood heater/cooler system. Under the temperature perturbation tests for blood storage, the cabinet should be limited under 30 seconds, which is adequate to blood storage.Another blood cooler bag have been developed to maintain 22±2℃ for platelet storage and transportation.It also reveals the feasibility for thermoelectric cooler for blood cold chain system. Furthermore, the application of thermoelectric coolers through patent search has been developed and assessed comprehensively.
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Liu, Zhuan-yu, and 劉顓瑜. "Numerical Simulation and Field Measurement Validation of cleanrooms for bio-medical application." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/30440123466456491901.
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碩士國立勤益科技大學
冷凍空調系
98
The HVAC systems for bio-cleanroom are energy-intensive and sophisticated in that they operate 24 hours per day year-round and use large amount of fresh air to deal with infectious problems and to dilute microorganisms. However, little quantitative information has been investigated about trade-off between energy-efficient HVAC system and indoor environment quality. The objective of this study is to present the field measurement approach on performance evaluation of the HVAC system for an cleanroom. Variable air volume terminal box was conducted to verify the compromise of energy-saving potential and indoor environment parameters including particle counts, microbial counts, pressurization, temperature and humidity. Field measurements of a full-scale operating room have been carried out at a district hospital in Taiwan. Numerical simulation has been applied to evaluate the air flow distribution and concentration contours while conducting the velocity reduction approach in the unoccupied operating room. Another field measurement and numerical simulation of a full-scale bio-cleanroom for vaccine cold storage cleanroom has been carried out as well. The results revealed that it is feasible to achieve satisfactory indoor environment by reducing the supply air volume (or velocity) in the unoccupied operating room. Optimal face velocity of HEPA filter and percentage of damper opening for the variable air volume terminal box could be obtained. Different velocity and temperature of supply air could be assessed not only by airflow distribute but also by transient simulation to achieve the design specification of 4℃ for vaccine storage. It will stimulate a more robust investigation of infection-controlled, energy-efficient and environment-comfortable HVAC system of cleanroom specific for unoccupied bio-medical application .
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Wang, Wei-Sheng, and 王韋盛. "A 1.6μW Successive Approximation analog-to-digital Converter for Bio-medical Signal Application." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/52285246553940087883.
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碩士國立清華大學
電機工程學系
100
This thesis proposes a novel 0.9V 10-bit Successive Approximation (SAR) analog-to-digital converter (ADC) based on half junction splitting (J.S.) and half binary weighted capacitor digital-to-analog converter (DAC) architecture. The kick-back noise of this structure due to comparator is larger than other DAC structures, thus a modified rail-to-rail comparator is used to reduce kick-back noise. This ADC is implemented in sub-threshold to reduce power consumption. In addition, dummy comparators are used in different sections of DAC to reduce the offset voltage caused by different gain errors of different DAC sections. The pre-simulation shows that the power dissipation is 1.27μW, SNDR is 61.7dB, ENOB is 9.96-bit, and figure-of-merit (FOM) is 12.8 fJ/conversion step. The chip has been fabricated with TMSC 0.18μm 1P6M CMOS process. The chip area is 893�e893μm2 with pads, and the core area is 440�e430μm2. The post-layout simulation shows that the power consumption is 1.72μW, the SNDR is 59.1dB, ENOB is 9.53-bit, and FOM is 23.2 fJ/conversion step. Under 0.9V supply voltage and 100KS/s sampling rate, the measurement result shows that the power dissipation was 1.59μW, SNDR was 46.47dB, ENOB was 7.43-bit, and FOM was 92.2 fJ/conversion step. This chip worked under 0.6 V supply voltage and consumed only 0.783μW. This low-power ADC is suitable for bio-medical signal acquisition. This low-power ADC is suitable for bio-medical signal acquisition.
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Wang, Huei-Jun, and 王(日慧)竣. "The research and development of 3D system package for wireless bio-medical application." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/25741127014538417075.
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碩士國立高雄第一科技大學
機械與自動化工程研究所
103
The purpose of this research is the development of wireless and biocompatible flexible type of biomedical systems. Use the Parylene for flexible substrate and compatible with wireless coil, SMD chip capacitors and ECG chip complete system integration by 3D package, with skin fit. After the integration of resistance value 3.61 Ω, and the resistance of the inductor coil former integration is 0.57 Ω. This study of 3D package process required on the wafer, using ICP etching the wafer with a close fit. Then and Parylene deposited into wafers, When the wafer is placed in the hole and because of the close fit, There may be resulting in gold can not be turned on, so that the Quality is reduced.Therefore, this study added flip-chip packaging technology, use of the silver paste (EPO-TEK H20E) making dispensing bumps, Complete the chip and substrate interconnect, resistance after integration of the value 49.2 Ω, The resistance of the inductor coil before the consolidation is 45.7 Ω, to prove the feasibility of the flip-chip package. In view of the system prior to the completion of the laboratory system for soaking accelerated life test found Parylene inadequate adaptation. Therefore, this study added annealing processes. And samples of some of the experimental use of parylene coating inductors. The system is placed in a non-oxidizing oven to a temperature of 200 ° C bake two days. It was found that parylene surface etiolated and embrittlement. Therefore, theis experiment will oven change as parylene machine''s use heating vacuum tube baking and annealing parameters. To design a successful completion of the sample annealed.
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Huang, Jhih-Wei, and 黃智瑋. "The research and development of 3D system integration and package for wireless implantable bio-medical application." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/50226979161060640887.
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