• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design of Ultra Wideband RF IC for Medical Imaging Applications

Bidhendi , Hossein Kassiri 08 1900 (has links)
<p> Being the second most important cause of death in women, breast cancer attracted great interest from many research groups in different fields developing techniques to prevent, detect or cure it. Due to the fact that this disease can be treated if it is detected in early stages, many projects in this field have focused on early breast cancer detection. Modern imaging technologies have helped in the detection of this cancer but they still have high false positive or negative rates indicating a great need for more research in early breast cancer detection.</p> <p> In 2002 the Federal Communication Commission allowed usage of 3.1 - 10.6 GHz frequency range for short-range medical and personal applications, and this has stimulated much research on one of the most interesting technologies for medical imaging. With the aid of advances in complementary metal-oxide-semiconductor technology as well as wireless communications, this imaging technology has steadily grow, and now, it has it has many attractive characteristics that makes it a perfect substitute for conventional imaging systems.</p> <p> This thesis reports on the design of some key circuits for an ultra-wideband transceiver architecture that can be used for medical imaging and especially for breast cancer detection. In this work, we concentrated on the receiver and two of its major blocks, namely, a low noise amplifier and a mixer are designed, simulated, fabricated and tested. Both of these circuits are designed in 0 .13 μm technology and Cadence tools are used for simulation and layout. </p> <p> First, a low noise amplifier is designed based on a common-source configuration with inductive degeneration and a third order Chebyshev input matching network. Using precise zero-pole analysis, two inductors have been added to the main architecture of amplifier to improve its gain bandwidth product. The designed circuit shows a very good performance in terms of all of design parameters. Voltage gain with a peak value of 18.6 dB and very acceptable flatness is achieved. Also the noise figure of this circuit had an average of 4.7dB and a minimum value of 3.3dB. Input and output impedance matching shows very satisfying performance for the whole range of 3.1 to 10.6 GHz. Moreover, linearity of the circuit shows a very good performance compared with other works with IIP3 of -0.996 dBm. Finally, all of these specifications are achieved while consuming only 4.01 mW and occupying 1.3 mm2 of chip area.</p> <p> Second, an ultra-wideband mixer is designed to work as a multiplier in this configuration, and to perform a critical function in correlation block. The mixer is designed for both super- and sub-threshold modes of MOSFET operation, and in both modes, it shows very acceptable performance. While super-threshold mixer shows much better characteristics in terms of gain, noise and linearity, the very low power consumption of sub-threshold circuit along with its reasonable performance in terms of gain, noise and linearity makes both circuits excellent designs for niche applications. Excellent conversion gain of 22.54dB is achieved for super-threshold circuit together with minimum noise figure of 7.4 dB and IIP3 of 2.67 dBm, while consuming 6.67 mW and having excellent input impedance matching all over the bandwidth. On the other hand, the sub-threshold circuit dissipates only 623 μW, with 13.44 dB of conversion gain and minimum noise figure of 7.67 and IIP3 of -7.47 dBm. This circuit has excellent input matching all over the UWB frequency range.</p> / Thesis / Master of Applied Science (MASc)
2

Diagnostic du cancer de la prostate par imagerie moderne : place de l’IRM dans la sélection des candidats à une surveillance active et dans la caractérisation des zones tumorales intra-prostatiques / Modern imaging in prostate cancer diagnosis : role of MRI in patient selection for active surveillance and for tumor characterization

Ouzzane, Adil 11 December 2014 (has links)
L’IRM représente une modalité d’imagerie du cancer de la prostate qui occupe une place de plus en plus importante pour le diagnostic positif. D’autres indications sont en cours de validation pour établir le pronostique, pour guider le traitement et pour assurer le suivi après traitement notamment partiel. La première partie de ce travail a porté sur les études cliniques de l’IRM dans la sélection des candidats à une surveillance active. Les performances de l’IRM particulièrement dans la détection des cancers antérieurs permettront de réduire le risque de sous-estimation initiale des tumeurs et par conséquent le risque de la reclassification au cours des protocoles de surveillance active. La seconde partie de ce travail a porté sur la corrélation entre les anomalies de signal à l’IRM et les zones tumorales et non tumorales intra-prostatiques. La validation d’une technique simple et reproductible de recalage a permis ensuite une corrélation des anomalies de signal enregistrées sur l’IRM et des paramètres histo-pathologiques quantitatifs des pièces opératoires de prostatectomie. / MRI is an increasingly important imaging modality for prostate cancer diagnosis. Further indications are being validated in prostate cancer to establish the prognostic, to guide treatment and to follow up patients especially after partial treatment. The first part of this work has focused on clinical studies of MRI in patient selection for active surveillance. The performance of MRI particularly in the detection of anterior cancers would reduce the risk of initial underestimation of tumor burden and therefore reduce the risk of reclassification during active surveillance protocols. The second part of this work has focused on the correlation between the signal abnormalities on MRI and intra-prostatic areas. We used a simple and reproducible technique for MRI and histopathology registration and we correlated signal abnormalities recorded on MRI with quantitative histopathological parameters at prostatectomy surgical specimens.

Page generated in 0.0574 seconds