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Mårtensson, Mattias. "Evaluation of Errors and Limitations in Ultrasound Imaging Systems." Doctoral thesis, KTH, Medicinsk teknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34177.
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There are binding regulations requiring safety and efficacy aspects of medical devices. The requirements ask for documentation that the devices are safe and effective for their intended use, i.e. if a device has a measuring function it must be correct. In addition to this there are demands for quality systems describing development, manufacturing, labelling, and manufacturing of a device. The requirements are established to guarantee that non-defective medical devices are used in the routine clinical practice. The fast rates in which the imaging modalities have evolved during the last decades have resulted in numerous new diagnostic tools, such as velocity and deformation imaging in ultrasound imaging. However, it seems as if the development of evaluation methods and test routines has not been able to keep up the same pace. Two of the studies in this thesis, Study I and IV, showed that computed tomography-based and ultrasound based volume measurements can yield very disparate measurements, and that tissue Doppler imaging-based ultrasound measurements can be unreliable. Furthermore, the new ultrasound modalities impose higher demands on the ultrasound transducers. Transducers are known to be fragile, but defective transducers were less of a problem earlier when the ultrasound systems to a lesser extent were used for measurements. The two other studies, Study II and III, showed that serious transducer errors are very common, and that annual testing of the transducers is not sufficient to guarantee an error free function. The studies in the thesis indicate that the system with Notified Bodies, in accordance with the EU’s Medical Device Directive, checking the function and manufacturing of medical devices does not work entirely satisfactory. They also show that the evaluation of new methods have led to the undesirable situation, where new measuring tools, such as volume rendering from imaging systems, and tissue Doppler-based velocity and deformation imaging in echocardiography are available for clinicians without proven knowledge about their accuracy.QC 20110527
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Mraz, Alex. "Evaluation of digital imaging systems used in highway applications." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000487.
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Liang, Jisheng. "Document structure analysis and performance evaluation /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/6043.
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Khullar, Siddharth. "Automatic multi-resolution spatio-frequency mottle metric (SFMM) for evaluation of macrouniformity /." Online version of thesis, 2010. http://hdl.handle.net/1850/12242.
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Bardsley, Tim. "The design and evaluation of an autostereoscopic computer graphics display." Thesis, De Montfort University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390980.
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Watson, Jonathan M. "Evaluation of spatial-spectral filtering in non-paraxial volume holographic imaging systems." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44854.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaves 144-148).
In this thesis, the properties of transmission-mode volume phase holograms as spatial-spectral filters in optical systems for microscopic medical imaging are evaluated. In experiment, the relationship between the angle of incidence and diffraction efficiency are invesitgated for wavelength-detuned multiplex holograms to establish the limits of the narrow bandwidth lateral field of view. The depth selectivity of the microscope with a volume hologram pupil is also measured and found to vary significantly with recording parameters and lateral shift of the probe point source in object space. This experiment is modified to incorporate controlled levels of spherical aberration, where the effect on the depth selectivity is evaluated. A novel resolution target designed specifically for the evaluation of this imaging system is described and imaged. A flexible approach based on the 1st-order Born approximation is implemented to simulate all aspects of the imaging system with a multiplex volume hologram pupil. The simulation is then used to verify and expand upon the experimental results. A mathematical treatment of the nature of the anomalous apparent curvature of the diffraction image is performed, showing that a volume grating recorded in plane has weak out-of-plane spatial filtering behavior.
by Jonathan M. Watson.
S.M.
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Thomas, Howard David. "Non-destructive evaluation of wood utility poles using computed axial tomography imaging." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4523.
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Thesis (M.S.) University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 28, 2007) Vita. Includes bibliographical references.
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Zhao, Jing. "Design and evaluation of a screen-CCD imaging system for medical radiology /." Online version of thesis, 1992. http://hdl.handle.net/1850/11253.
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Liu, Xiaoqiu. "Microscopic tissue image processing for pathological evaluation /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9999304.
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Payne, Kathryn A. "Evaluation of causes of large 96-h and 120-h track errors in the Western North Pacific." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FPayne.pdf.
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Sokolic, Iván. "Criteria to Evaluate the Quality of Pavement Camera Systems in Automated Evaluation Vehicles." Scholar Commons, 2003. https://scholarcommons.usf.edu/etd/1254.
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The use of high technology in common daily tasks is boarding all areas of civil engineering; pavement evaluation is not the exception. Accordingly, current pavement imaging systems have been able to collect images at highway speeds and with the use of proper software, this digital information can be translated into pavement distress reports in which all distresses are classified and presented by their type, extent, severity, and location. However, a number of issues regarding the quality of pavement images and the appropriate conditions to acquire them, remain to be addressed. These issues surfaced during the development of a pavement evaluation vehicle for the Florida Department of Transportation (FDOT).
The work involved in this thesis proposes basic criteria to evaluate the performance of pavement imaging systems. Mainly four parameters (1) spatial resolution, (2) brightness resolution, (3) optical distortion, and (4) signal to noise ratio, have been identified to assess the quality of a pavement imaging system. First, each of the four parameters is studied in detail in USF's Visual Imaging Laboratory to formulate relevant criteria that can be used to evaluate imaging systems. Then, the developed criteria are used to evaluate the FDOT Survey Vehicle's pavement imaging system. The evaluation speed does not seem to have any significant influence on the spatial resolution, brightness resolution and signal to noise ratio. Little or no optical distortion was observed on the images on wheel paths. Limitations of the imaging system were also determined in terms of the brightness resolution and noise. The conclusions drawn from this study can be used to (1) enhance pavement imaging systems and (2) setup appropriate guidelines to perform automated distress surveys, under varying lighting conditions and speeds to obtain good quality images.
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Wang, Zhipeng. "A framework for the Analysis and Evaluation of Optical Imaging Systems with Arbitrary Response Functions." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195108.
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The scientific applications and engineering aspects of multispectral and hyperspectral imaging systems have been studied extensively. The traditional geometric spectral imaging system model is specifically developed aiming at spectral sensors with spectrally non-overlapping bands. Spectral imaging systems with overlapping bands also exist. For example, the quantum-dot infrared photodetectors (QDIPs) for midwave- and longwave-infrared (IR) imaging systems exhibit highly overlapping spectral responses tunable through the bias voltages applied. This makes it possible to build spectrally tunable imaging system in IR range based on single QDIP. Furthermore, the QDIP based system can be operated as being adaptive to scenes. Other optical imaging systems like the human eye and some polarimetric sensing systems also have overlapping bands. To analyze such sensors, a functional analysis-based framework is provided in this dissertation. The framework starts from the mathematical description of the interaction between sensor and the radiation from scene reaching it. A geometric model of the spectral imaging process is provided based on the framework. The spectral response functions and the scene spectra are considered as vectors inside an 1-dimensional spectral space. The spectral imaging process is abstracted to represent a projection of scene spectrum onto sensor. The projected spectrum, which is the least-square error reconstruction of the scene vectors, contains the useful information for image processing. Spectral sensors with arbitrary spectral response functions are can be analyzed with this model. The framework leads directly to an image pre-processing algorithm to remove the data correlation between bands. Further discussion shows that this model can also serve the purpose of sensor evaluation, and thus facilitates comparison between different sensors. The spectral shapes and the Signal-to-Noise Ratios (SNR) of different bands are seen to influence the sensor's imaging ability in different manners, which are discussed in detail. With the newly defined SNR in spectral space, we can quantitatively characterize the photodetector noise of a spectral sensor with overlapping bands. The idea of adaptive imaging with QDIP based sensor is proposed and illustrated.
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Casella, Stacey E. "Gamut extension algorithm development and evaluation for the mapping of standard image content to wide-gamut displays /." Online version of thesis, 2008. http://hdl.handle.net/1850/8416.
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Lewis, Zachary Ludon. "Evaluation of thermal variations on concrete pavement using three dimensional line laser imaging technology." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50406.
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Jointed Plain Concrete Pavements (JPCP) are some the most popular forms of concrete pavement that are used in the state of Georgia. Each year the Georgia Department of Transportation (GDOT) inspects and surveys their highways to determine what condition the pavement is in and if any rehabilitation is required to maintain the integrity of the highway. These annual surveys include the JPCP and the key concrete pavement characteristics that are used to determine the condition of the JPCP are the faulting at the joints and the roughness of the section. Since it is well known that concrete will exhibit slight movement when subjected to thermal variations it is possible that the these minor movements could have an impact on the measured slab properties used to rate the JPCP section. The focus of this research is to develop a methodology to use three dimensional technologies to capture JPCP surface data under a variety of thermal conditions, to develop a procedure to collect and analyze concrete temperature data, to develop a method to analyze the surface data and how to correlate all of the data that was collected. Three test sites were chosen that covered a total of 6 test sections that were composed of 25 slabs and 26 joints each. This provided a total of 150 slabs and 156 joints that were used for analysis.
A single slab was selected as a test specimen to install thermal logging devices into so that the temperature distributions through the slab could be investigated. Three positions were monitored to determine if the position that the temperature gradient was measured was critical. It was found that the temperature followed a similar trend for all of the positions with the profiles being slightly shifted from each other. It was also concluded that the temperature in the bottom of the slab was approximately the same as the temperature in the base. It was discovered that the maximum positive temperature gradient occurred simultaneously with the maximum ambient air temperature and the maximum surface temperature. The results showed that the surface temperature followed a trend similar to the ambient air temperature. However the surface temperature was greater throughout the day.
The faulting analysis results indicated that out of the 156 joints inspected only 15 showed a variation in the average faulting that was greater than the 0.5 mm (0.02 in) accuracy of the sensors used to collect the JPCP surface data. Further investigation revealed that there was no clear trend between the temperature change and the average faulting variation. It was concluded that if there was a change in the average faulting due to temperature it is smaller than what can be depicted by the sensing vehicle and it is less than the 1 mm (0.04 in) measurement accuracy that is specified in the American Association of State Highway and Transportation Officials (AASHTO) R36-04 specification which governs the accuracy requirements for automated faulting measurement methods.
The International Roughness Index (IRI) was the method used to measure the roughness on each test site for each data collection run. This resulted in 336 IRI values that were inspected to determine whether there was an impact from the temperature variations. The IRI results showed that the roughness of the test sections did vary through the day. After it was found that the IRI did vary through the day the IRI distributions were compared to the temperature distribution and 7 out of the 12 distributions studied showed a weak correlation between the temperature and the IRI. The amount of variation in the IRI was not quantified because the exact accuracy of the IRI values attained from the sensing vehicle was unknown. However it was attempted to validate the system and determine the accuracy but one of the validation test sections showed disappointing results while the other two showed promising results. Further research is required to fully evaluate the sensing vehicles ability and accuracy when measuring the IRI.
A procedure was also developed to extract the longitudinal and transverse curvature of the concrete pavement slabs. Three test slabs were selected at one of the test sites and curvature results were generated using the developed procedure. The curvature results were visually and quantitatively assessed. The visual analysis indicated that the curvature profiles measured by the 3D line lasers did change throughout the data collection, but the patterns did not follow what was expected and a correlation could not be created with the temperature. The quantitative results for the longitudinal curvature revealed that one of the slabs did show a pattern that followed the temperature changes during the data collection, but it did show as much as 4.65 mm (0.183 in) of change between consecutive data collection runs. The longitudinal curvature results for the other two slabs did not show a trend and exhibited unlikely changes in the curvature measured between consecutive data collection runs, which in some instances the deviation was as much as 12.09 mm (0.480 in). For the transverse curvature one of the slabs indicated that the curvature did not change during the data collection, while the other two showed sudden changes as high as 2.16 mm (0.085 in) between consecutive data collection runs. The developed procedure is only preliminary and needs to be further evaluated and refined for it to be able to adequately measure the curvature of as slab. The results also need to be verified using actual measured ground truth curvatures to determine the validity of using the developed procedure and the 3D line laser data to measure the curvature of concrete slabs. Once the procedure is proven to produce reliable results it should be compared to other curvature computation methods, such as those that utilize road profilers or LIDARs, to determine which method is the best.
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Salih, Shafik. "Generation of 3D autostereoscopic integral images using computer simulated imaging systems." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/10477.
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Production of artificial Three-Dimension (3-D) images was the aim of many researches over hundreds of years. 3-D images are the images that create sense of depth when viewing them. 3-D images are closer to the real world scenes than 2-D images due to the 3-D effect or the sense of depth the 3-D images provide. Sense of depth can be caused by binocular cues including convergence and parallax. Convergence is created by the difference between the angles of the left eye and the right eye viewing axes. Parallax is the effect of viewing with one eye a view of the scene that is inherently shifted to the view seen by the other eye. Several techniques have targeted the creation of 3-D images with the mentioned cues. The technique is preferred when it is able to create 3-D images so that the viewer can view these images without wearing special glasses and the occurrence of viewer fatigue. Integral photography that was invented in 1908 is able to meet the previous requirements. Based on integral photography, several techniques, research and studies have been published. The purposes of this thesis include the computer simulation of flexible integral photography systems, the computer generation of good quality 3-D static and animated integral images using the simulated systems, optimising the generation process to be more accurate, less expensive, more effective, and faster, and producing a portable specialist software tool to achieve these targets. New techniques and algorithms are needed to meet these purposes. A literature survey was carried out about the closest researches and studies to the subject of computer-generated integral images; these were compared with the new techniques introduced in this study to prove the advantages and the necessity of these new techniques. The closest technique to the suggested techniques was implemented using more developed tools to compare the quality of the resulting integral images with the targeted integral images that are going to be produced using the tools and algorithms proposed in this thesis. A method to simulate an imaging system and produce integral images based on the new technique of dividing the view volume of the scene was introduced, explained, proved, and implemented with a program designed for this purpose. To optimise the processing time and the image quality, the previous method is developed, new features are added to the resulting integral images, and better performance was achieved by introducing the method of Displacing the Virtual Camera Target (DCT). Application software with Graphical User Interface is designed and implemented to allow users to select the required parameters of the imaging system and the required features of the resultant integral images. The software tool that is based on the developed techniques and employing OpenGL is useful to simulate the imaging systems, tune their parameters before the actual implementation of these systems, and as a result, save time and materials when designing these systems. The introduced techniques and the software tools are faster, more effective, and cheaper original methods to help in optimising both the integral imaging systems and the quality of integral images. These software tools based on the new techniques can be used on a wide range of devices and platforms because these are employing the portable Application Interface OpenGL. With these methods, integral imaging systems are simulated, and optimised; good quality static and animated integral images were created.
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Kwong, Kim-hung. "An evaluation of 3D-GIS as a public engagement tool in environmental impact assessment." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36860827.
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Nematbakhsh, Mohammed Ali. "Design and performance evaluation of a high-speed fiber optic integrated computer network for imaging communication systems." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184597.
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In recent years, a growing number of diagnostic examinations in a hospital are being generated by digitally formatted imaging modalities. The evolution of these systems has led to the development of a totally digitized imaging system, which is called Picture Archiving and Communication System (PACS). A high speed computer network plays a very important role in the design of a Picture Archiving and Communication System. The computer network must not only offer a high data rate, but also it must be structured to satisfy the PACS requirements efficiently. In this dissertation, a computer network, called PACnet, is proposed for PACS. The PACnet is designed to carry image, voice, image pointing overlay, and intermittent data over a 200 Mbps dual fiber optic ring network. The PACnet provides a data packet channel and image and voice channels based on Time Division Multiple Access (TDMA) technique. The intermittent data is transmitted over a data packet channel using a modified token passing scheme. The voice and image pointing overlay are transferred between two stations in real-time to support the consultive nature of a radiology department using circuit switching techniques. Typical 50 mega-bit images are transmitted over the image channel in less than a second using circuit switching techniques. A technique, called adaptive variable frame size, is developed for PACnet to achieve high network utilization and short response time. This technique allows the data packet traffic to use any residual voice or image traffic momentarily available due to variation in voice traffic or absence of images. To achieve optimal design parameters for network and interfaces, the PACnet is also simulated under different conditions.
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Lewandowski, Mark E. "The Design, Fabrication, and Evaluation of Mobile Point-of-Care Systems for Cellular Imaging in Microfluidic Channels." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1512576064493513.
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Sarkar, Abhijit. "Evaluation of the color image and video processing chain and visual quality management for consumer systems /." Online version of thesis, 2008. http://hdl.handle.net/1850/7061.
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Alahmad, Haitham N. "Evaluation of Phantoms Used in Image Quality Performance Testing of Dental Cone Beam Computed Tomography Systems." University of Toledo Health Science Campus / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=mco1438985667.
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Burch, Douglas Paul. "Implementation and evaluation of a general aviation synthetic vision display system." Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1176143438.
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Phyu, Su Myat. "Targeting of the PI3K/AKT/mTOR signalling pathway and associated kinases in breast and colon cancer cells and response evaluation by molecular imaging techniques." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=238576.
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The phosphatidylinositol-3-kinase/AKT (Protein Kinase B)/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway, downstream of tyrosine kinase receptors, is upregulated in human cancers including breast and colon cancers. Glycogen synthase kinase 3 (GSK 3) is a serine/threonine protein kinase plays important role in various cellular processes including glycogen synthesis mediated by insulin signalling pathway. Moreover, 5' adenosine monophosphate activated protein kinase (AMPK), a crucial cellular energy sensor, has regulatory role in cell growth and proliferation through mTOR pathway. Phosphatidylcholine (PtdCho) is the major phospholipid in the mammalian cell membranes and is mainly synthesized by the CDP-choline pathway. Malignant transformation has been reported to be associated with altered choline metabolism. Hyperactivation of the PI3K/AKT signalling pathway upregulates the key enzymes of phospholipid metabolism. The first line antidiabetic drug, metformin, modulates glucose and concomitant lipid metabolism through AMPK activation. Studies suggest phosphatidylcholine biosynthesis and breakdown through CDP-choline pathway are modulated by glucose metabolism and de novo fatty acid synthesis. Cancer cell growth inhibitory effect of PI3K/AKT/mTOR/GSK3 pathway inhibitors and metformin were investigated by cytotoxic assay, western blot and cell cycle analysis in breast and colon cancer cells. IC50 values of anticancer drugs and combination indices between drug combinations were determined. 31P-NMR was carried out on cell extracts after drug treatments. [14C (U)] glucose and [3H] choline incorporation into lipids were also determined. All inhibitors targeting PI3K/AKT/mTOR signaling pathway, GSK3 and metformin have cancer cell growth inhibition. By 31P-NMR, PI3K/AKT/mTOR pathway inhibition induced agent-specific changes in PCho intensity. Increased UDP-sugars observed in breast and colon cancer cell extracts treated with LY294002 and AZD8055, an effect abrogated by inclusion of a GSK3 inhibitor. A link between glycolytic intermediates and phosphatidylcholine biosynthesis was investigated by metformin and GSK3 inhibitor in breast and colon cancer cells.
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Kwong, Kim-hung, and 鄺劍雄. "An evaluation of 3D-GIS as a public engagement tool in environmental impact assessment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36860827.
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Imbert, Villà Marc. "Design and performance evaluation of millimeter-wave flat lens antennas for communications, radar and imaging applications." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/397648.
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Millimeter-wave systems introduce a set of particular severe requirements from the antenna point of view in order to achieve specific performances. In this sense, high directive antennas are required to overcome the huge extra path loss. Moreover, each particular application introduces additional requirements. For example, in very high throughput (VHT) wireless personal area networks (WPANs) communication systems at 60 GHz band beam-steering antennas are needed to deal with high user random mobility and human-body shadowing characteristic of indoor environments. Similarly, beam-steering capabilities are
also needed in automotive radar applications at 79 GHz, since the determination of the exact position of an object is essential for most of the functions realized by the radar sensor. In the same way, beam-scanning, which is still commonly mechanically performed nowadays, is also needed in passive imaging systems at 94 GHz. Finally, from the integration perspective, the antennas must be small, low-profile, light weight and low-cost, in order to be successfully integrated in a commercial millimeter-wave wireless system.
For these reasons, many types of antenna structures have been considered to achieve high directivity and beam-steering capabilities for the aforementioned millimeter-wave communication, radar and imaging applications at 60, 79 and 94 GHz.
The most part of the currently adopted solutions are based on the expensive, complex and bulky phased-array antena concept. Actually, phased-array antenna systems can scan the beam at a fast rate. However, they require a complex integration of many expensive, lossy and bulky circuits, such as solid-state phase shifters and beam-forming networks.
This doctoral thesis has contributed to the study, development, and assessment of the performance of innovative antena solutions in order to improve the existing architectures at millimeter-wave frequencies, conveniently solving the problems related specifically to short-range high data rate communication systems at 60 GHz WPAN band (including future 5G millimeter-wave systems), automotive radar sensors at 79 GHz band, and communications, radar, and imaging systems at 94 GHz. The specific goals pursued in this work, focused on defining an alternative antenna architecture able to achieve a full reconfigurable 2-D beam-scanning of high gain radiation beams at millimeter-wave frequencies, has been fulfilled. In this
sense, this thesis has been mainly devoted to study in depth and practically develop the fundamental part of an innovative switched-beam antenna array concept: novel inhomogeneous gradient-index dielectric flat lenses, which, despite their planar antenna profile configurations, allow full 2-D beam-scanning of high gain radiation beams. A transversal study, going from theoretical investigations, passing by numerical analysis, new fabrication strategies, performance evaluation, and to full experimental assessment of the new antenna architectures in real application environment has been successfully carried out.Los sistemas a frecuencias de ondas milimétricas introducen una serie de requisitos muy estrictos desde el punto de vista de la antena con el objetivo de conseguir unos rendimientos específicos. En este sentido, se requieren antenas con una muy alta directividad con tal de conseguir superar las enormes pérdidas adicionales por propagación. Además, cada aplicación en concreto introduce unos requisitos adicionales. Por ejemplo, en redes de área personal de alta velocidad para sistemas de comunicación a la banda de 60 GHz, antenas con la capacidad de reconfiguración del haz de radiación son necesarias para poder tratar la problemática de la alta movilidad de los usuarios en entornos cerrados. De la misma forma, capacidades de reconfiguración de la orientación del haz de radiación son necesarias en aplicaciones relacionadas con radar de automoción a 79 GHz, dado que la determinación de la posición exacta de un objeto es esencial para muchas de las funciones del sensor de radar. De forma muy similar, la capacidad de apuntamiento del haz, que muchas veces todavía se realiza mediante sistemas mecánicos, es también imprescindible en sistemas de escaneo para aplicaciones biomédicas y de seguridad a 94 GHz. Finalmente, desde la perspectiva de la integración, las antenas deben ser eléctricamente pequeñas, ligeras, y económicas para poder ser incorporadas a un sistema inalámbrico comercial a frecuencias de onda milimétricas. Por todos estos motivos, diferentes tipos de estructuras de antenas han sido propuestos para conseguir alta directividad, junto con capacidades de reconfiguración y apuntamiento del haz de radiación para las aplicaciones anteriormente mencionadas y descritas en la banda de 60, 79, y 94 GHz. La solución tradicionalmente adoptada en este tipo de casos està estrictamente basada en el siempre caro, complejo y aparatoso concepto del phased-array. De hecho, los phased-arrays permiten el rápido escaneo de haces de radiación de alta directividad. Sin embargo, el hecho que requieran una compleja integración de muchos y caros componentes a alta frecuencia, tales como desfasadores de estado sólido o redes de conformación, los cuales introducen ciertos niveles de pérdidas, siendo además aparatosos, hacen que esta solución resulte inviable. La presente tesis doctoral contribuye al estudio, desarrollo, y ensayo experimental del rendimiento de soluciones de antenas innovadoras para la mejora de las existentes arquitecturas de antena en la banda frecuencial de las ondas milimétricas, convenientemente solucionando los problemas asociados específicamente a los sistemas de comunicación de corto alcance y alta velocidad a 60 GHz (incluyendo los futuros sistemas 5G a milimétricas), a los sistemas de radar de automoción a 79 GHz, y a los sistemas de comunicación, radar, y escaneo para aplicaciones a 94 GHz. Los objetivos específicos perseguidos en este trabajo académico, focalizados en definir una arquitectura alternativa de antena, capaz de conseguir una completa reconfiguración y escaneo de los haces de radiación en dos dimensiones del espacio a frecuencias de onda milimétricas, se han conseguido plenamente. En este sentido, esta tesis doctoral ha sido dedicada esencialmente al estudio en profundidad y desarrollo práctico de la parte fundamental del innovador concepto del switchedbeam array: nuevas lentes dieléctricas inhomogéneas de gradiente de índice con estructura plana, las cuales, a pesar de su configuración física totalmente llana, permiten una reconfiguración total, en dos dimensiones del espacio, de haces de radiación de alta directividad. Un estudio eminentemente transversal, que abarca desde la investigación teórica, pasando por el análisis numérico, nuevas metodologías y técnicas de fabricación, evaluación de rendimientos, hasta una completa caracterización y ensayo del rendimiento en entornos reales de aplicación de las nuevas arquitecturas de antena, se ha llevado a cabo con total éxito.
Els sistemes a freqüències d'ones mil·limètriques introdueixen una sèrie de requisits molt estrictes des del punt de vista de l'antena per tal d’aconseguir uns rendiments específics. En aquest sentit, es requereixen antenes amb una alta directivitat per aconseguir superar les enormes pèrdues addicionals per propagació. A més a més, cada aplicació en concret introdueix uns requeriments addicionals . Per exemple, en xarxes d'àrea personal d'alta velocitat per a sistemes de comunicació a la banda de 60 GHz, antenes amb la capacitat de reconfiguració del feix de radiació són necessàries per tal de poder tractar la problemàtica de l'alta mobilitat dels usuaris en entorns tancats . De la mateixa manera, capacitats de reconfiguració de l'orientació del feix de radiació són necessàries en aplicacions associades a radar d'automoció a 79 GHz, donat que la determinació de la posició exacta d'un objecte és essencial per moltes de les funcions portades a terme pels ens or del radar. De forma molt similar, la capacitat d'apuntament del feix, que moltes vegades encara es realitza per mitjà de sistemes mecànics, és també imprescindible en sistemes d'escaneig per aplicacions mèdiques i de seguretat a 94 GHz. Finalment, des de la perspectiva de la integració, les antenes han de ser petites en termes elèctrics, lleugeres, i econòmiques per tal de poder ser incorporades en un sistema sense fils comercial a freqüència d'ones mil·limètriques. Per aquestes raons , diversos tipus d'estructures d'antenes han sigut proposats per aconseguir alta directivitat, conjuntament amb la capacitat d'apuntament del feix de radiació per les aplicacions anteriorment descrites a les bandes de 60, 79, i 94 GHz. La solució tradicionalment adoptada en aquests casos és estrictament basada en el sempre car, complexe, i aparatós concepte del phased-array. De fet, els phased-arrays tenen la capacitat de reconfigurar a gran velocitat feixos de radiació d'alta directivitat. Tot i això, el fet que requereixin la complexa integració de molts components cars a alta freqüència, amb certs nivells de pèrdues i aparatosos, com són els desfasadors d'estat sòlid, i les xarxes de conformació, fan d'aquesta solució inviable. La present tesis doctoral contribueix a l'estudi, des envolupament, i assaig experimental del rendiment de solucions d'antenes innovadores per tal de millorar les existents arquitectures d'antena a la banda freqüencial de les ones mil·limètriques, convenientment solucionant els problemes associats específicament als sistemes de comunicació de rang proper d'alta velocitat a 60 GHz (incloent els futurs sistemes 5G a mil·limètriques ), als sistemes de radar d'automoció a la banda dels 79 GHz, i als sistemes de comunicació, radar, i escaneig per aplicacions a 94 GHz. Els objectius específics perseguits en aquest treball acadèmic, focalitzats en definir una arquitectura d'antena alternativa, capaç d'aconseguir una completa reconfiguració i escaneig dels feixos de radiació en dues dimensions de l'espaia freqüències d'ona mil·limètriques , s'han plenament aconseguit. En aquest sentit, aquesta tesis doctoral s'ha dedicat essencialment a l'estudi en profunditat i desenvolupament pràctic de la part fonamental de l'innovador concepte del switched-beam array: noves lents dielèctriques inhomogenees de gradient d'índex amb estructura planar, les quals, tot i preservar una configuració física totalment plana, permeten una reconfiguració total en dues dimensions de l'espai de feixos de radiació d'alta directivitat. Un estudi transversal, que comprèn des de la investigació teòrica, passant per l'anàlisi numèric, noves metodologies i tècniques de fabricació, avaluació de rendiments, fins a una completa caracterització i assaig del rendiment en entorns reals d'aplicació de les noves arquitectures d'antena s'ha dut a terme amb total èxit.
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Quinlivan, Mitchell. "Functions of the cholinergic system in the morbidities associated with Alzheimer's disease and the further evaluation of tools for the molecular imaging of this system." Connect to full text, 2007. http://hdl.handle.net/2123/1933.
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Thesis (Ph. D.)--University of Sydney, 2007.Cotutelle thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Pharmacology, Faculty of Medicine, University of Sydney and to the Doctoral School: Santé, Sciences et Technologies, University of Tours (France). Title from title screen (viewed Sept. 21, 2007). Includes bibliography. Also issued in print.
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Ganapathy, Priya. "Development and Evaluation of a Flexible Framework for the Design of Autonomous Classifier Systems." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1261335392.
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Kemp, Jacobus Nicholas, H. L. Zietsman, and G. Stevens. "Evaluating image classification techniques on ASTER data for lithological discrimination in the Barberton Greenstone Belt, Mpumalanga, South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/4933.
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Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2005.81 Leaves printed on single pages i-xi, preliminary pages and numbered pages 1- 70. Includes bibliography, list of tables and list of figures.
Digitized at 300 dpi color PDF format (OCR), using KODAK i 1220 PLUS scanner.
ENGLISH ABSTRACT: Geological field mapping is often limited by logistical and cost constraints as well as the scope and extent of observations possible using ground-based mapping. Remote sensing offers, among others, the advantages of an increased spectral range for observations and a regional perspective of areas under observation. This study aimed to determine the accuracy of a collection of image classification techniques when applied to ASTER reflectance data. Band rationing, the Crosta Technique, Constrained Energy Minimization, Spectral Correlation Mapping and the Maximum Likelihood Classifier were evaluated for their efficiency in detecting and discriminating between greenstone and granitoid material. The study area was the Archaean Barberton Greenstone Belt in the eastern Mpumalanga Province, South Africa. ASTER reflectance imagery was acquired and pre-processed. Training and reference data was extracted from the image through visual inspection and expert knowledge. The training data was used in conjunction with USGS mineral spectra to train the five classification algorithms using the ERDAS's software package. This resulted in abundance images for the target materials specified by the training data. The Maximum Likelihood Classifier produced a classified thematic map. The reference data was used to perform a rigorous classification accuracy assessment procedure. All abundance images were thresholded to varying levels, obtaining accuracy statistics at every level. In so doing, threshold levels could be defined for every abundance image in such a way that the reliability of the classification was optimized. For each abundance image, as well as for the output map of the Maximum Likelihood Classifier, user's- and producer's accuracies as well as kappa statistics were derived and used as comparative measures of efficiency between the five techniques. This information was also used to assess the spectral separability of the target materials. The Maximum Likelihood Classifier outperformed the other techniques significantly, achieving an overall classification accuracy of 81.1% and an overall kappa value of 0.748. Greenstone rocks were accurately discriminated from granitoid rocks with accuracies between 72.9% and 98.5%, while granitoid rocks showed very poor ability to be accurately distinguished from each other. The main recommendations from this study are that thermal infrared and gamma-ray data be considered, together with better vegetation masking and an investigation into object orientated techniques.
AFRIKAANSE OPSOMMING: Geologiese veldkartering word algemeen beperk deur logistiese en koste-verwante faktore, sowel as die beperkte bestek waartoe waarnemings met veld-gebasseerde tegnieke gemaak kan word. Afstandswaarneming bied, onder andere, 'n vergrote spekrale omvang vir waarnemings en 'n regionale perspektief van die area wat bestudeer word. Hierdie studie was gemik daarop om die akkuraatheid van 'n versameling beeld-klassifikasie tegnieke, toegepas op ASTER data, te bepaal. Bandverhoudings, die Crosta Tegniek, "Constrained Energy Minimization", Spektrale Korrellasie Kartering, en Maksimum Waarskynlikheid Klassifikasie is evalueer op grond van hul vermoë om groensteen en granitoied-rotse op te spoor en tussen hulle te onderskei. Die studiegebied was die Argalese Barberton Groensteengordel in die oostelike Mpumalanga Provinsie in Suid Afrika. 'n ASTER refleksie beeld is verkry, waarop voorverwerking uitgevoer is. Opleidings- en verwysingsdata is van die beeld verkry deur visuele inspeksie en vakkundige kennis. Die opleidingsdata is saam met VSGO mineraalspektra gebruik om die vyf klassifikasie algoritmes met behulp van die ERDAS sagteware pakket op te lei. Die resultaat was volopheidsbeelde vir die teikenmateriale gespesifiseer in die opleidingsdata. Die Maksimum Waarskynlikheid algoritme het 'n geklassifiseerde tematiese beeld gelewer. Met behulp van die verwysingsdata is 'n streng akkuraatheidstoetsing prosedure uitgevoer. Vir alle volopheidsbeelde is 'n reeks drempelwaardes gestel, en by elke drempelwaarde is akkuraatheidsstatistieke afgelei. Op hierdie manier kon 'n drempelwaarde vir elke volopheidsbeeld vasgestel word sodat die drempelwaarde die betroubaarheid van die klassifikasie optimeer. Vir elke volopheidsbeeld, asook vir die tematiese kaart verkry van die Maksimum Waarskynlikheid klassifikasie, is gebruikers- en produsent-akkuraathede en kappa statistieke bereken. Hierdie waardes is gebruik as vergelykende maatstawwe van akkuraatheid tussen die vyf tegnieke, asook van die spektrale skeibaarheid van die onderskeie teikenmateriale. Die Maksimum Waarskynlikheid klassifikasie het die beste resultate gelewer, met 'n algehele klassifikasie akkuraatheid van 81.1%, en 'n gemiddelde kappa waarde van 0.748. Groensteenrotse kon met hoë akkuraathede van tussen 72.9% en 98.5% van granitoiedrotse onderskei word, terwyl granitoiedrotse 'n swak vermoë getoon het om van mekaar onderskei te word. Die belangrikste aanbevelings vanuit hierdie studie is dat termiese uitstralingdata asook gamma-straal data geimplimenteer word. Beter verwydering van plantegroei en 'n studie na die lewensvatbaarheid van objekgeorienteerde metodes word ook aanbeveel.
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Rudraraju, Prasad V. "Motion parameter evaluation, camera calibration and surface code generation using computer vision." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182460668.
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Dolasinski, Brian David. "Nonlinear systems for frequency conversion from IR to RF." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1417804168.
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Huisman, Maximiliaan. "Vision Beyond Optics: Standardization, Evaluation and Innovation for Fluorescence Microscopy in Life Sciences." eScholarship@UMMS, 2019. https://escholarship.umassmed.edu/gsbs_diss/1017.
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Fluorescence microscopy is an essential tool in biomedical sciences that allows specific molecules to be visualized in the complex and crowded environment of cells. The continuous introduction of new imaging techniques makes microscopes more powerful and versatile, but there is more than meets the eye. In addition to develop- ing new methods, we can work towards getting the most out of existing data and technologies. By harnessing unused potential, this work aims to increase the richness, reliability, and power of fluorescence microscopy data in three key ways: through standardization, evaluation and innovation.
A universal standard makes it easier to assess, compare and analyze imaging data – from the level of a single laboratory to the broader life sciences community. We propose a data-standard for fluorescence microscopy that can increase the confidence in experimental results, facilitate the exchange of data, and maximize compatibility with current and future data analysis techniques.
Cutting-edge imaging technologies often rely on sophisticated hardware and multi-layered algorithms for reconstruction and analysis. Consequently, the trustworthiness of new methods can be difficult to assess. To evaluate the reliability and limitations of complex methods, quantitative analyses – such as the one present here for the 3D SPEED method – are paramount.
The limited resolution of optical microscopes prevents direct observation of macro- molecules like DNA and RNA. We present a multi-color, achromatic, cryogenic fluorescence microscope that has the potential to produce multi-color images with sub-nanometer precision. This innovation would move fluorescence imaging beyond the limitations of optics and into the world of molecular resolution.
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Pandey, Preetanshu. "Application evaluation of a prototype backscatter imaging LDV system (BILS)." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2660.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains xi, 100 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-86).
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Han, Zhimin. "Hyperspectral endoscopy imaging: system development, clinical evaluation, and further application." Diss., Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55026.
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Hyperspectral (HS) imaging combines spectral measurement of a pixel with 2D imaging technology. It is capable to provide a series of images containing both spectral and spatial information, and has been widely used in medical domain. However, most researches on medical HS imaging are regarding ex-vivo biopsy or skin and oral mucosa. The study on HS imaging regarding in-vivo disease lags far behind.
In this thesis, we developed a novel flexible HS endoscope system. It is capable to obtain a series of HS images in vivo in a non-contact way among the wavelength range of 405 – 665 nm. After a lot of time-consuming modifying and debugging work, this new system has high stability and convenience to be applied in clinic now. We evaluated this system in clinic. First, we got ethics approval for clinical trials. Then, we obtained HS images regarding gastrointestinal (GI) diseases inside patients using this system. As far as we know, this type of in-vivo image data has not been reported in previous literatures. Thus using these HS images, we built a database for GI mucosa. Next, we analyzed some typical HS images tentatively. The method of Recursive Divergence is implemented to extract valuable and diagnostic information from these HS images. The results prove the effect and applicability of this new HS endoscope system, which has shown the great potential to be used as a platform and guidance for further medical studies. To further apply the analysis results in clinic, we propose a novel Adaptive Narrow-Band Imaging (ANBI) method based on band selection of HS images of a specific type of disease. It is expected that the new technique has higher accuracy, sensitivity, and specificity compared to conventional Narrow-Band Imaging (NBI) technique. In this thesis, we also discuss the future direction of the system improvement. Especially, to improve light intensity and signal-noise-ratio of HS images in wide-field view, we propose a new imaging method using broad- and overlapped-band filters. Although this method only performs greatly on the foundation of accurate image registration, we hope to apply it in our system in the future.
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Burke, Thomaz Nogueira. "Desenvolvimento de um sistema para avaliação dos desvios da coluna vertebral em três dimensões- Spine3D." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-02082013-153241/.
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Introdução: Escoliose é definida como um complexo desalinhamento tridimensional da coluna vertebral na qual há o aparecimento de uma curvatura lateral no plano coronal, normalmente associada com o aplanamento das curvaturas no plano sagital e rotação vertebral em seu eixo longitudinal. O padrão ouro para seu diagnóstico e monitoramento é a medida radiográfica pelo ângulo de Cobb, que possui como principais desvantagens o fato de não avaliar as curvas em três dimensões e expor os pacientes, principalmente os que estão em fase de crescimento, a consideráveis doses de radiação. Objetivo: Esta pesquisa teve como objetivo principal o desenvolvimento de um sistema de avaliação e representação da coluna vertebral em três dimensões, capaz de possibilitar ao usuário a análise quantitativa dos desvios da coluna vertebral nos planos coronal, sagital e transverso. São objetivos secundários estimar a precisão e a exatidão do sistema proposto, e avaliar a sua aplicabilidade a partir de um estudo de caso. Métodos: O Sistema desenvolvido, denominado de Spine 3D, é baseado no uso do controle de videogame Wiimote para rastrear LEDs infravermelhos que compõe um marcador multiplanar em uma cena, e tem como objetivo reconstruir em um ambiente 3D a pose das vértebras torácicas e lombares e, com isto, obter as variáveis angulares e de translação que descrevem seu alinhamento nos planos coronal, sagital e transverso. O experimento para a avaliação da exatidão e precisão consistiu em posicionar o marcador a 50 centímetros de distância do Wiimote, ambos alinhados em um mesmo plano. O marcador foi transladado em intervalos de 10 mm e rotacionado em 5°, 10°, 20° e 30° nos eixos X, Y e Z, com auxílio de um inclinômetro e um paquímetro digital. Os dados foram coletados a 100 Hz. A exatidão foi calculada comparando os resultados encontrados pelo sistema com os valores obtidos pelo inclinômetro e paquímetro digital. A precisão foi calculada a partir do desvio-padrão dos pontos coletados. Resultados: A exatidão média do sistema foi de 0,90° e 0,78mm. A precisão média do sistema foi de 0,62° e 0,42mm. Para o ângulo de Cobb na escoliose, a exatidão e precisão foram de 1,46° e 1,72°, e para a cifose torácica e lordose lombar, a exatidão e precisão foram de 2,82° e 1,60°, respectivamente. Durante o estudo de caso, a diferença entre o Spine3D e a radiografia, para o ângulo de Cobb foi de 1,3° para escoliose curva torácica e 2,24° para escoliose curva lombar. Conclusão: O sistema mostrou ter boa exatidão e precisão após os testes de validação interna. O estudo de caso sugere que a técnica possui potencial para aplicação clínica na avaliação dos desvios da coluna vertebral em três dimensões.Introduction: Scoliosis is a complex three-dimensional malalignment of the vertebral column in which there is lateral curvature of the spine in the coronal plane, usually associated with flattening of the contour in the sagittal plane and rotation of the vertebrae around their longitudinal axes. Routine clinical analysis of the scoliotic spine is currently based on the radiographic measurement of Cobb angle. Although considered as the golden standard, it has the disadvantage of look over only the two-dimensional aspects of the curve and, over a period of years, the patient will be exposed to a large dose of radiation, especially in early onset curves. There is evidence that this may increase the risk of developing several types of cancer. Objective: This paper describes a new low-cost and radiation-free system to evaluate the three-dimensional aspects of scoliosis, and its concurrent validation in terms of accuracy and precision. Its applicability was tested in a case study. Methods: The system, named Spine3D, has the ability to track an infrared beacon equipped with LEDs (IRLED) to reconstruct the pose of each lumbar and thoracic vertebra in 3D space. The system also calculates the spine alignment to the coronal, sagittal and transverse planes. For accuracy and precision evaluation of the system, the beacon was positioned 50 cm away from the IR camera (Wiimote), aligned with in the same plane. The beacon was increasingly translated at 10 mm intervals and rotated at 5°, 10°, 20° and 30° on all three axes. The capture achieved rate was of 100 Hz roughly and accuracy was calculated comparing the results of Spine3D, digital paquimeter and digital inclinometer. Precision was considered as the standard deviation of the collected data. Results: The average accuracy obtained for the system is 0.90° and 0.78 mm, with precision of 0.62° and 0.42 mm. For Cobb angle calculations in coronal plane, accuracy and precision were of 1.46° and 1.72°, and for thoracic kyphosis and lumbar lordosis, the values were 2.82° and 1.60°. During the case study, the difference between the Cobb angle measured by Spine3D and radiography was 1.3° for thoracic scoliosis curve and 2.24° for lumbar scoliosis curve. Conclusion: The Spine3D system offers a non-invasive and radiation-free alternative for three-dimensional spine assessment and representation. Future studies should indicate if the measures taken by the Spine3D system have correlation with the Cobb angle measured by other methods.
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Li, Xiping. "Web-based Medical Imaging Simulation System for Education and Research." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/682.
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In this work, a major effort has been made to establish an Internet accessible system for medical imaging simulation as a convenient service under the cloud computing environment. First, an Internet accessible, medical imaging education platform has been developed. It includes teaching and dynamic assessment tracking system for five commonly used imaging modalities. The system is integrated by the open source MySQL database software that manages updating materials and also tracks students’ learning engagements, which allow the reliability and appropriateness of the on-line teaching material and assessment methods to be optimized. The evaluation results have shown increased learning gains promisingly. Second, a prototype simulation service platform has been established. It is based on a job-oriented work flow to provide different kinds of service to users to perform medical imaging simulation. These simulations not only include the straightforward CT data reconstruction based on Radon transform, but also the sophisticated PET imaging simulation based on GATE as well. The QGATE’s client-server configuration can manage the GATE system to queue and monitor the submitted simulation scripts and return simulation results. The system is suitable for classroom training and easy to use for students or new users to the field of nuclear medicine imaging simulation. Finally, based on the developed simulation platform, a simulation study on PET imaging has been carried out. Event-based dynamic justification method has been tested based on the phantoms generated by NCAT associated with different breathing signals. The results show its potential capability of motion correction for PET data acquisition.
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Yocky, David Alan. "Characterization and evaluation of a photostimulable phosphor x ray imaging system." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184529.
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This dissertation presents the characterization and evaluation of a new radiological imaging modality, Toshiba Computed Radiography (TCR) 201. The characteristics of the TCR storage phosphor imaging plates such as energy-dependent x-ray quantum efficiency, stored signal decay, low exposure rate signal build-up, and spontaneous and stimulated gain measures are presented. The TCR 201 system is characterized by the signal transfer curve, the total root-mean-squared (rms) output noise, the signal-to-noise ratio, the modulation transfer function (MTF), its noise power spectrum (NPS), and the detective quantum efficiency (DQE). The system rms noise is photon-limited for exposures less than 1.0 mR, but has contributions from phosphor structure and quantization noise for exposures higher than 1.0 mR. The phosphor's information factor is shown to explain deviations from ideal photon-limited noise for exposures of less than 1.0 mR. The MTF of the system is measured for standard imaging plates, 10% at 2.8 lp/mm, and for high resolution imaging plates, 10% at 4.4 lp/mm. An expression for the NPS is statistically derived, and experimental measurements confirm the expression and show an increase in uncorrelated noise power above 1.0 mR which is consistent with rms measurements. Expressions for the DQE are presented. A psychophysical study is performed to directly compare the TCR to film/screen combinations in imaging low-contrast objects. The results of this study show the TCR provides better images for detectability as a function of exposure. Also, the use of the TCR 201 as a two dimensional dosimeter and in single-shot dual energy subtraction is presented.
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Galan, Cherrez Andres Moroni. "Design and Evaluation of a CMOS Contact-Imaging System for Microfluidics." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/7219.
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A CMOS contact-imaging system for microfluidics is presented. The microsystem integrates a five-layer PDMS microfluidic network and a CMOS image sensor fabricated in a standard 0.18 µm technology. The CMOS image sensor consists of two 10×1-pixel array, an amplifier, and a control logic. The imager is able to achieve a low dark signal of 1.67 mV/s, a maximum integration time of 514 s, and a high dynamic range of 75.2 dB at 1 s integration time. The microfluidic device integrates several actuated valve to achieve a fully automated lab-on-a-chip. This work also presents a quantitative comparison of the photomultiplier tube (PMT) and the CMOS contact-imaging system. The CMOS-microfluidic device is validated using an on-chip chemiluminescent analyte.
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Palaniyappan, Naaventhan. "Quantitative magnetic resonance imaging in evaluating haemodynamic changes in portal hypertension." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/45274/.
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The majority of complications in patients with cirrhosis result from the development and progression of portal hypertension characterised by increased intrahepatic resistance and progressive splanchnic vasodilation. Hepatic venous pressure gradient (HVPG) measurement is the only validated technique to accurately evaluate changes in portal pressure. However, HVPG measurements are invasive and available only in specialised hepatology units, precluding its use in routine clinical practice. In the first study, we evaluated the use of non-contrast quantitative magnetic resonance imaging (MRI) as a surrogate measure of portal pressure. 30 patients undergoing HVPG measurement were prospectively recruited. MR parameters of longitudinal relaxation time (T1), perfusion of the liver and spleen (by arterial spin labelling), and blood flow in the portal, splanchnic and collateral circulation (by phase-contrast MRI) were assessed. We estimated the liver stiffness measurement (LSM) and Enhanced Liver Fibrosis (ELF) score. The correlation of all non-invasive parameters with HVPG was evaluated. The mean (range) HVPG of the patients was 9.8 (1-22) mmHg, and 14 patients (48%) had clinically significant portal hypertension (CSPH, HVPG ≥10 mmHg). Liver T1 relaxation time, splenic artery and superior mesenteric artery velocity correlated significantly with HVPG. Using multiple linear regression, liver T1 and splenic artery velocity remained as the two parameters in the multivariate model significantly associated with HVPG (R=0.90, p < 0.001). This correlation was maintained in patients with CSPH (R=0.85, p < 0.001). A validation cohort (n=10) showed this linear model provided a good prediction of HVPG. LSM and ELF score correlated significantly with HVPG in the whole population but the correlation was absent in CSPH. In conclusion, MR parameters related to both hepatic architecture and splanchnic haemodynamics correlate significantly with HVPG. This proposed model, confirmed in a validation cohort, could replace the invasive HVPG measurement. In the second part, we studied the use non-invasive MRI to dynamically assess changes in hepatic and collateral blood flow, liver perfusion and oxygenation in response to ingestion of a test meal (meal challenge), and hyperoxia and hypercapnia (gas challenge). These changes were compared between healthy subjects and patients with compensated cirrhosis (CC). In the meal challenge study, we evaluated the blood flow in the portal vein, hepatic artery and azygos vein, liver perfusion and blood oxygenation (using transverse relaxation time (T2*) mapping). Measures were collected at baseline and at 6-7 minute intervals from 20 to 65 minutes following a test meal (440 ml; 660 kcal) in 10 healthy participants and 10 CC patients. In healthy participants, we observed a postprandial increase in portal vein flow from baseline coupled with a reduction in hepatic artery flow from baseline, reflecting the hepatic artery buffer response (HABR). In CC patients, changes in portal vein and hepatic artery flow were smaller, with no clear HABR. In healthy participants, postprandial liver perfusion increased, but not in CC patients. There was no change in liver T2* for either group. In the gas challenge study, we evaluated the blood flow in portal vein and hepatic artery, liver perfusion and liver T2* during hyperoxia and hypercapnia in 10 healthy subjects and 4 patients with compensated cirrhosis. A sequential gas delivery breathing circuit and a prospective, feed-forward gas delivery system (RespiractTM, Thornhill Research Inc., Toronto, Canada) was used to control and monitor end-tidal O2 (PETO2) and CO2 (PETCO2) partial pressures. Hyperoxia was targeted at PETO2 ~500mmHg and hypercapnia was aimed at PETCO2 ~6mmHg above resting value. The study design consisted of 5 blocks. Blocks 1, 3 and 5 were 5 min periods at resting PETCO2 and PETO2. Blocks 2 and 4 were, in a random order, 5 mins of hyperoxia (with a 2 min transition up and down) or 5 mins of hypercapnia. We observed an increase in portal vein velocity during hypercapnia among the healthy subjects and patients with cirrhosis. There was no significant changes in liver T2* but the full-width-half-maximum (FWHM) of the distribution of the liver T2* increased in response to hyperoxia and hypercapnia in both groups. Subjects with low T2* at baseline exhibited a smaller change in FWHM following the gas challenge. The within session and inter-session coefficient of variation (CoV) the blood flow measurement using phase-contrast MRI in healthy subjects was less than 15%. If our findings are confirmed in external validation studies, non-invasive MRI can be used as a surrogate measure of HVPG. Assessment of postprandial dynamic changes in hepatic, splanchnic and collateral circulation using MRI could potentially be used to stratify patients with portal hypertension and study the effects of potential novel treatments for portal hypertension.
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Qiu, Deqiang, and 邱德強. "Diffusion tensor imaging in evaluating normal and abnormal white matter development in childhood." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41508324.
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Mahirah, Binti Jahari. "Double Lighting Machine Vision System for Rice Quality Evaluation." Kyoto University, 2017. http://hdl.handle.net/2433/228241.
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Mather, Andrew Raymond. "Evaluation of the planar germanium SmartPET system for use in positron emission imaging." Thesis, University of Liverpool, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439486.
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Zhu, Jinhao. "Uniquimer 3D, a software system for structural DNA nanotechnology design, analysis and evaluation /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20ZHU.
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Ibrahim, Mohamed Asim Yousif. "Co-processing of drugs and co-crystal formers and its effect on pharmaceutical dosage-form performance : co-crystallization of urea/2-methoxybenzamide, caffeine/malonic acid, caffeine/oxalic acid and theophylline/malonic acid systems : solid-state characterization including imaging, thermal, X-ray and Raman spectroscopic techniques with subsequent evaluation of tableting behaviour." Thesis, University of Bradford, 2008. http://hdl.handle.net/10454/12760.
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This dissertation has focused on the solid-state characterization of different co-crystal system as well as the effect of co-crystallization of these systems on pharmaceutical dosage form performance. Urea/ 2-MB, caffeine/ malonic acid, caffeine/ oxalic acid and theophylline/ malonic acid co-crystals were prepared using co-grinding- and co-precipitation techniques. In addition, the synthesis of co-crystals through two novel methods has been demonstrated. This includes compaction and convection mixing. The solid-state characterization of the co-crystals has been carried out using XRPD, Raman spectroscopy, DSC, TGA, hot-stage microscopy and SEM. After preparation of co-crystals, tablets have been produced from co-ground-, co-precipitated-, and physical mixtures using Compaction Studies Press (Kaleva), and the data were recorded to compare between the different mixtures, regarding compactibilty, compressibility and deformational properties. The DSC results showed that the physical mixtures of all systems, formed co-crystals during heating process. For systems of urea/ 2-MB, caffeine/ malonic acid and theophylline/ malonic acid, the co-ground mixture produced tablets with higher tensile strength compared with either co-precipitated or physical mixture. However, for caffeine/ oxalic acid system, the tensile strengths of compacts produced from the physical mixture were greater than those obtained from either co-ground or co-precipitated mixtures. The Heckel data suggested that urea/ 2-MB, caffeine/ malonic acid and theophylline/ malonic acid systems are Type 1 materials, as an extensive linearity during compression was indicative of a plastic deformation mechanism, while the caffeine/ oxalic acid system was Type 2 materials. However, the co-precipitated mixture of urea/ 2-MB system was the least compressible, as it possessed the greatest value of yield pressure (85 MPa) and the highest elastic recovery (7.42%). The co-precipitated mixture of both of caffeine/ malonic acid and theophylline/ malonic acid systems was the most compressible with small yield pressure values of (44 & 80 MPa) and elastic recovery of (7.2% & 6.56%), respectively. The co-ground mixture of caffeine/ oxalic acid possessed the highest value of yield pressure (166 MPa) and thus the lowest compressibility among other mixtures. Furthermore, the addition of microcrystalline cellulose and α-lactose monohydrate has affected the crystallinity as well as the tableting properties of the co-crystals. After the addition of excipients, the tensile strength of compacts was about 2 times higher than any other mixture. Finally, urea/ 2-MB and caffeine/ malonic acid co-crystals were successfully synthesized through convection mixing and compaction.
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Ibrahim, Mohamed Asim Y. "Co-processing of drugs and co-crystal formers and its effect on pharmaceutical dosage-form performance. Co-crystallization of urea/ 2-methoxybenzamide, caffeine/ malonic acid, caffeine/ oxalic acid and theophylline/ malonic acid systems: Solid-state characterization including imaging, thermal, X-ray and Raman spectroscopic techniques with subsequent evaluation of tableting behaviour." Thesis, University of Bradford, 2008. http://hdl.handle.net/10454/12760.
Full textAbstract:
This dissertation has focused on the solid-state characterization of different co-crystal system as well as the effect of co-crystallization of these systems on pharmaceutical dosage form performance. Urea/ 2-MB, caffeine/ malonic acid, caffeine/ oxalic acid and theophylline/ malonic acid co-crystals were prepared using co-grinding- and co-precipitation techniques. In addition, the synthesis of co-crystals through two novel methods has been demonstrated. This includes compaction and convection mixing. The solid-state characterization of the co-crystals has been carried out using XRPD, Raman spectroscopy, DSC, TGA, hot-stage microscopy and SEM. After preparation of co-crystals, tablets have been produced from co-ground-, co-precipitated-, and physical mixtures using Compaction Studies Press (Kaleva), and the data were recorded to compare between the different mixtures, regarding compactibilty, compressibility and deformational properties. The DSC results showed that the physical mixtures of all systems, formed co-crystals during heating process. For systems of urea/ 2-MB, caffeine/ malonic acid and theophylline/ malonic acid, the co-ground mixture produced tablets with higher tensile strength compared with either co-precipitated or physical mixture. However, for caffeine/ oxalic acid system, the tensile strengths of compacts produced from the physical mixture were greater than those obtained from either co-ground or co-precipitated mixtures. The Heckel data suggested that urea/ 2-MB, caffeine/ malonic acid and theophylline/ malonic acid systems are Type 1 materials, as an extensive linearity during compression was indicative of a plastic deformation mechanism, while the caffeine/ oxalic acid system was Type 2 materials. However, the co-precipitated mixture of urea/ 2-MB system was the least compressible, as it possessed the greatest value of yield pressure (85 MPa) and the highest elastic recovery (7.42%). The co-precipitated mixture of both of caffeine/ malonic acid and theophylline/ malonic acid systems was the most compressible with small yield pressure values of (44 & 80 MPa) and elastic recovery of (7.2% & 6.56%), respectively. The co-ground mixture of caffeine/ oxalic acid possessed the highest value of yield pressure (166 MPa) and thus the lowest compressibility among other mixtures. Furthermore, the addition of microcrystalline cellulose and α-lactose monohydrate has affected the crystallinity as well as the tableting properties of the co-crystals. After the addition of excipients, the tensile strength of compacts was about 2 times higher than any other mixture. Finally, urea/ 2-MB and caffeine/ malonic acid co-crystals were successfully synthesized through convection mixing and compaction.Islamic University of Omdurman and the Ministry of Higher Education in Sudan
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Parsons, Caron Saeko. "The development of a patient reported outcome measure and imaging modalities in the evaluation of haemorrhoidal disease." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/28466/.
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With the advent of DGHAL and PPH, treatments that purport to work by disrupting the arterial supply of haemorrhoids, there has been resurgence in interest in the vascular theory of pathogenesis of haemorrhoids. Despite uncertainty surrounding recurrence and complication rates there has been significant uptake of the new surgical approach due to decreased post-operative pain. However this has not been matched by discussion or evaluation of how haemorrhoidal disease and successful outcome should be evaluated. This thesis evaluates different approaches to the measurement of the burden of haemorrhoidal disease to the patient. A patient reported outcome measure was designed, administered and evaluated by the investigator. Reliability, reproducibility, validity, responsiveness and acceptability have been demonstrated. Three-dimensional ultrasound was used to acquire volumetric data and power Doppler angiography from the anal canal, which was shown to be reliable. Measures of power Doppler angiography were shown to be significantly lower in healthy volunteers than in patients. This technique represents promising value as an outcome measure of haemorrhoidal disease. A dual isotope-surgical nuclear probe technique attempted to measure change in volume of haemorrhoids following rubber band ligation, however consistent results were not obtained. Magnetic resonance imaging was able to demonstrate anal cushions and haemorrhoids, and the feasibility of this method has been demonstrated.
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Mutswangwa, Christopher T. "Evaluating the usability of an X-ray imaging system in forensic pathology." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29577.
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Post mortem imaging (PMI) is increasingly being adopted as an alternative to invasive autopsies in forensic pathology. PMI can be used as a sole technique or adjunct to an autopsy. The Lodox Xmplar-dr is an X-ray imaging system that has been adopted for use in PMI. The purpose of this study was to evaluate the perceived usability of this imaging system by focusing on the satisfaction of forensic pathologists in use of the system. Assessment of satisfaction was guided by the subjective satisfaction characteristics of likability, pleasure, comfort and trust. Incorporation of user needs into updated system designs may lead to greater perceived ease of use, acceptance and adoption, resulting in increased device utilisation. The study location was the Lodox Xmplar-dr installation site at the Salt River Forensic Laboratory, Cape Town. Five forensic pathologists were observed using the Xmplar-dr system and four were interviewed on their experience using the system. A qualitative research design which used thematic analysis with the aid of NVIVO11 qualitative data analysis software was used to extract key usability and satisfaction themes emerging from the data, to show the extent of user satisfaction. Two key themes emerged. These were categorised as forensic pathologist-related, which focused on the hedonistic and subjective aspects of their satisfaction with the system, and systemrelated, which centred on the satisfaction users derived from the system’s ability to meet their pragmatic and objective expectations in their use of the system. In general, the forensic pathologists were satisfied with the Xmplar-dr system and it exceeded their expectations. Pleasure was derived from the ability of the system to increase work throughput by reducing the need to perform a dissectional post-mortem unless it was deemed absolutely necessary, i.e. when cause of death could not be determined from the X-ray images generated by the system. Participants felt that the system was an indispensable device when performing post mortems. Likability came from the ease of learning to use the basic functions of the system; the study participants stated that the system aided them in determining cause of death and saved time, in line with the definition of the likability characteristic that is centred on the extent to which a user is satisfied with perceived achievements of pragmatic goals. Trust was derived from participants’ views that the system worked as intended, although there could be improvements in terms of robustness, reliability and the imaging system`s support services. Image manipulation on the human-computer interface (HCI) and image representation were concerns highlighted. Most functions could be performed through the system’s HCI rather than by manipulation of the body being examined; this increased the physical comfort satisfaction characteristic. The need for manual placement of bodies on the system`s table by assistants and the associated health consequences were however raised as a concern that diminished the comfort-in-use characteristic of satisfaction. Understanding the user experience of the forensic pathologists who use the Lodox Xmplar-dr system to perform post mortems enabled the identification of areas for improvement. The improvements may increase user satisfaction resulting in better utilisation of the imaging system. The insights gained may be useful for the design of other imaging systems used in forensic pathology.
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Qiu, Deqiang. "Diffusion tensor imaging in evaluating normal and abnormal white matter development in childhood." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41508324.
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Howes, Stuart C. "Design of a noninvasive system for the evaluation of collagen scaffolds using MRI." Link to electronic thesis, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-052507-131736/.
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Borrelli, Leonard Michael. "A PET system comparison utilizing the American College of Radiology accreditation phantom." Connect to full-text via OhioLINK ETD Center, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=mco1140102086.
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Thesis (M.S.)--Medical University of Ohio, 2005."In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Major advisor: Michael J. Dennis. Includes abstract. Document formatted into pages: iii, 82 p. Title from title page of PDF document. Title at ETD Web site: A positron emission tomography (PET) system comparison utilizing the American College of Radiology accreditation phantom. Bibliography: pages 43-44.
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Khong, Pek-Lan. "Diffusion tensor MR imaging in the evaluation of treatment-induced white matter injury in childhood cancer survivors." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38320666.
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Lee, Paul Chong Chan. "A QUALITATIVE AND QUANTITATIVE ANALYSIS OF SOFT TISSUE CHANGE EVALUATION BY ORTHODONTISTS IN CLASS II NON EXTRACTION ORTHODONTIC TREATMENT USING THE 3dMD SYSTEM." Master's thesis, Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/217032.
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Oral BiologyM.S.
With the advent of cephalometrics in the 1930s, numerous studies have focused on the profile of a face to achieve a more esthetic orthodontic treatment outcome. With such heavy emphasis on facial esthetics, a shift in focus from the profile view to the oblique view has become necessary as the smile in the oblique view is what the general public evaluates. The purpose of this pilot study was to determine whether the current tools for diagnosis and treatment evaluation are sufficient. Currently, 2-dimensional composite photographs are utilized in evaluating the soft tissue. At Temple University, 3-dimensional images, which show all sides of the patient's face, are used adjunctively to 2-dimensional composite photographs. In this study, faculty members at the Temple University Department of Orthodontics were asked to complete surveys after viewing two different image modalities, 2-dimensional images and a 3-dimensional video of the same patient. They were asked to fill out the soft tissue goals for specific facial landmarks. Patient photos were in the smiling view as current literature lacks studies on this view. Faculty members' responses from analyzing the 2-dimensional images and 3-dimensional video for each patient were compared to determine which areas had frequent discrepancies from using two different image modalities. During the survey, a voice recorder captured any comments regarding the images. The ultimate goal of this qualitative pilot study was to identify when 3-dimensional imaging is necessary in treatment planning and evaluation, with an added hope to further advance research in 3-dimensional imaging and its vast possibilities to advance the field of orthodontics. Based on the data collected, the following conclusions were made: 1. The qualitative data highlighted that 3-dimensional imaging would be necessary in cases with skeletal deformities. 2. In the oblique view, 3-dimensional imaging is superior than 2-dimensional imaging by showing more accurate shadow, contour, and depth of the soft tissue. 3. Further improvement is necessary to create a virtual patient with treatment simulation abilities. 4. The comfort level among orthodontists of 2-dimensional imaging was higher than 3-dimensional imaging. With more widespread use of 3-dimensional imaging, more orthodontists may gradually reach a higher comfort level in using this relatively new technology. 5. Faculty members expressed high willingness to use 3-dimensional imaging if improvement in new technology could allow for more manipulation and accurate soft tissue prediction. 6. 3-dimensional imaging is superior in its efficiency, quick capture time, and lack of need for multiple images. Implementation of 3-dimensional imaging could streamline the records process and help with practice efficiency without compromising the image quality. 7. Both patients and orthodontists may benefit from using 3-dimensional imaging. Patients can see an accurate representation of themselves and possibly view their own treatment simulation upon further improvement in current technology. Orthodontists would benefit with much more accurate images that may serve as the virtual patient. 8. Besides the exorbitantly high cost, faculty members thought that more advances were needed and the current benefit was not great enough to justify the investment. The results were consistent with other studies that used the oblique view in that the 2-dimensional oblique view lacks depth and does not provide adequate information. With further improvement in current 3-dimensional imaging, this technology can benefit orthodontists in visualizing their patients. In addition, patients can benefit by hopefully seeing a live and accurate simulation of themselves instantly as a virtual patient. With these benefits of 3-dimensional imaging, it may one day be the new standard in patient records in the field of orthodontics.
Temple University--Theses