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Ruth, Serge van. "Hyperthermic intracavitary chemotherapy in abdomen and chest." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2003. http://dare.uva.nl/document/69072.
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Hutchinson, Erin R. "Intracavitary ultrasound phased arrays for thermal therapies." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43336.
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Khoury, Dirar Shafiq. "Recovery of endocardial potentials from intracavitary potential data." Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1056746257.
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Buchanan, Mark Thomas 1967. "An ultrasound phased array system for intracavitary hyperthermia." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278159.
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Intracavitary ultrasound hyperthermia applicators have the potential to better heat certain tumor sites, especially in the pelvic region, than external techniques. To allow deep, controlled heating, an intracavitary phased array has been developed. The hardware required to drive the array was also developed; including amplifiers, phase shifters, power meters and matching circuits. The entire system is computer controlled and capable of driving up to 64 individual ultrasound transducers. This system was used to conduct acoustic field measurements and in vivo perfused kidney experiments with the phased arrays. These results show that these arrays focus as predicted, and are capable of controlling the heating field by electrically controlling the position of the focus.
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Diederich, Chris John. "The design and development of intracavitary ultrasound arrays for hyperthermia." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185172.
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This study investigated the design concepts and development of two types of intracavitary ultrasound applicators for use in hyperthermia cancer treatment. Acoustic field calculations, thermal simulations, bench experiments, and in vivo and in vitro studies were utilized to determine and then evaluate the final designs. Each of these devices appears to offer a significant improvement over the existing RF and microwave intracavitary hyperthermia methods. The first type of applicator consisted of a multielement array with the power level to each element independently controlled. This is an important feature in that it allows the power deposition along the length of the array to be modified during a treatment to account for changes in blood perfusion or local heating rates. A temperature regulated water bolus provided acoustic coupling and additional control over the depth of the maximum temperature from the cavity wall. These applicators were tested in vivo and in vitro and were able to induce controlled transrectal heating at depths of 2-3 cm in the canine rectum and prostate gland. The second type of applicator to be developed was an electrically focused array. Computer simulations were used to perform a parametric study of the design of such arrays. These results have indicated that cylindrical arrays of a practical size (7.5 cm long, 1.5 cm O.D.), resonating at 0.5 MHz with individual elements that are up to 1.5 mm wide, can preferentially heat regions 2-5 cm from the array surface. In addition, it was shown that the temperature distribution can be further controlled by scanning the focal position within the target volume, producing heated regions up to 4 cm wide. A practical design was developed and a prototype 0.5 MHz array was constructed and tested in degassed water. These results were in good agreement with the corresponding theoretical simulations.
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Leung, To-wai. "High-dose-rate intracavitary brachytherapy in the treatment of nasopharyngeal carcinoma." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39557315.
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梁道偉 and To-wai Leung. "High-dose-rate intracavitary brachytherapy in the treatment of nasopharyngeal carcinoma." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557315.
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Pike, G. Bruce (Gilbert Bruce). "Three dimensional stereotaxic intracavitary and external beam isodose calculation for treatment of brain lesions." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65439.
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Sokka, Shunmugavelu D. (Shunmugavelu Doraivelu) 1975. "Design and evaluation of linear intracavitary ultrasound phased array for MRI-guided prostate ablative therapies." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80207.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 76-82).
by Shunmugavelu D. Sokka.
S.M.
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Jiménez-Pérez, Guillermo. "Deep learning and unsupervised machine learning for the quantification and interpretation of electrocardiographic signals." Doctoral thesis, Universitat Pompeu Fabra, 2022. http://hdl.handle.net/10803/673555.
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Las señales electrocardiográficas, ya sea adquiridas en la piel del paciente (electrocardiogamas
de superficie, ECG) o de forma invasiva mediante cateterismo (electrocardiogramas
intracavitarios, iECG) ayudan a explorar la condición y función
cardíacas del paciente, dada su capacidad para representar la actividad eléctrica del
corazón. Sin embargo, la interpretación de las señales de ECG e iECG es una tarea
difícil que requiere años de experiencia, con criterios diagnósticos complejos para
personal clínico no especialista, que en muchos casos deben ser interpretados durante
situaciones de gran estrés o carga de trabajo como en la unidad de cuidados
intensivos, o durante procedimientos de ablación por radiofrecuencia (ARF) donde
el cardiólogo tiene que interpretar cientos o miles de señales individuales. Desde
el punto de vista computacional, el desarrollo de herramientas de alto rendimiento
mediante técnicas de análisis basadas en datos adolece de la falta de bases de datos
anotadas a gran escala y de la naturaleza de “caja negra” que están asociados con
los algoritmos considerados estado del arte en la actualidad. Esta tesis trata sobre
el entrenamiento de algoritmos de aprendizaje automático que ayuden al personal
clínico en la interpretación automática de ECG e iECG. Esta tesis tiene cuatro
contribuciones principales. En primer lugar, se ha desarrollado una herramienta de
delineación del ECG para la predicción de los inicios y finales de las principales
ondas cardíacas (ondas P, QRS y T) en registros compuestos de cualquier configuración
de derivaciones. En segundo lugar, se ha desarrollado un algoritmo de
generación de datos sintéticos que es capaz de paliar el impacto del reducido tamaño
de las bases de datos existentes para el desarrollo de algoritmos de delineación.
En tercer lugar, la metodología de análisis de datos de ECG se aplicó a datos similares,
en registros electrocardiográficos intracavitarios, con el mismo objetivo de
marcar inicios y finales de activaciones locales y de campo lejano para facilitar la
localización de sitios de ablación adecuados en procedimientos de ARF. Para este
propósito, el algoritmo de delineación del ECG de superficie desarrollado previamente
fue empleado para preprocesar los datos y marcar la detección del complejo
QRS. En cuarto y último lugar, el algoritmo de delineación de ECG de superficie
fue empleado, junto con un algoritmo de reducción de dimensionalidad, Multiple
Kernel Learning, para agregar la información del ECG de 12 derivaciones y lograr
la identificación de marcadores que permitan la estratificación del riesgo de muerte
súbita cardíaca en pacientes con cardiomiopatía hipertrófica.Electrocardiographic signals, either acquired on the patient’s skin (surface electrocardiogam, ECG) or invasively through catheterization (intracavitary electrocardiogram, iECG) offer a rich insight into the patient’s cardiac condition and function given their ability to represent the electrical activity of the heart. However, the interpretation of ECG and iECG signals is a complex task that requires years of experience, difficulting the correct diagnosis for non-specialists, during stress-related situations such as in the intensive care unit, or in radiofrequency ablation (RFA) procedures where the physician has to interpret hundreds or thousands of individual signals. From the computational point of view, the development of high-performing pipelines from data analysis suffer from lack of large-scale annotated databases and from the “black-box” nature of state-of-the-art analysis approaches. This thesis attempts at developing machine learning-based algorithms that aid physicians in the task of automatic ECG and iECG interpretation. The contributions of this thesis are fourfold. Firstly, an ECG delineation tool has been developed for the markup of the onsets and offsets of the main cardiac waves (P, QRS and T waves) in recordings comprising any configuration of leads. Secondly, a novel synthetic data augmentation algorithm has been developed for palliating the impact of small-scale datasets in the development of robust delineation algorithms. Thirdly, this methodology was applied to similar data, intracavitary electrocardiographic recordings, with the objective of marking the onsets and offsets of events for facilitating the localization of suitable ablation sites. For this purpose, the ECG delineation algorithm previously developed was employed to pre-process the data and mark the QRS detection fiducials. Finally, the ECG delineation approach was employed alongside a dimensionality reduction algorithm, Multiple Kernel Learning, for aggregating the information of 12-lead ECGs with the objective of developing a pipeline for risk stratification of sudden cardiac death in patients with hypertrophic cardiomyopathy.
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Segala, James J. "Interface dosimetry for electronic brachytherapy Xoft Axxent intracavitary breast balloon applicators and fluorescence anisotropy imaging of quantum dots /." View online ; access limited to URI, 2009. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3368005.
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Merrilees, N. Katherine (Ngaire Katherine) 1974. "Design of control systems for focused and unfocused intracavitary ultrasound arrays for the thermal treatment of prostate disease." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9623.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (leaf 102).
Heat transfer in tissue during induced hyperthettnia treatments for prostate disease can be modeled as a multi-input multi-output (MIMO) system. For both focused and unfocused ultrasound arrays, the control of this MIMO system can follow either of two paths. First, a method of system identification can be used to derive a system model from which a gain matrix for a controller can be calculated with methods like that of the linear quadratic regulator (LQR). Second, a trial and error controller can be designed and tuned for each new treatment. Although the first option has clear benefits, this work shows that, with MRI thermometry, the ti.me delay in the temperature feedback loop is sufficient to make any method of system identification difficult within the ti.me constraints of a clinical setting. A proportional plus integrator plus derivative (PID) controller was designed to control the system in computer simulations. This single-input, single-output (SISO) controller was weighted to better control the system by providing parameters scaled to compensate for the geometry of the treatment and thermal coupling of tissue. While the controller performed very well under the conditions for which it was tuned, the level of performance decreased when the parameters of the simulation, such as the rate of perfusion in the tissue were altered. For the unfocused array, a program was written in C++ to run the array and implement the controller for a hyperthermia treatment using MRI thermometry for the feedback signal.
by N. Katherine Merrilees.
M.Eng.
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Leroy, Henri-Arthur. "Thérapie photodynamique au 5-ALA appliquée aux glioblastomes." Thesis, Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILS007.
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Les tumeurs cérébrales primitives de haut grade représentent un enjeu de soins depremière importance. En effet, les plus fréquentes d’entre elles ; les glioblastomes (GBM) sont incurables. Leur médiane de survie est d’une quinzaine de mois lorsque les patients ont bénéficié d’une chirurgie d’exérèse optimale suivie des traitements adjuvants recommandés que sont la radiothérapie et la chimiothérapie. Malgré ces traitements, la récidive est la règle,et ce la plupart du temps à proximité de la cavité d’exérèse initiale. De nouvelles techniques ont vu le jour afin d’améliorer le contrôle local de la tumeur, citons l’implantation des pastilles de carmustine au sein de la cavité chirurgicale. Toutefois le bénéfice de ce type de thérapeutique complémentaire reste limité.C’est dans ce contexte que l’idée d’appliquer la thérapie photodynamique (PDT) aux GBM a émergé. Ce traitement repose sur la présence synchrone de trois éléments : une molécule photosensibilisante, de l’oxygène et l’illumination à une longueur d’onde spécifique déclenchant une cascade métabolique favorisant la mort des cellules gliales cancéreuses.Grâce au développement de photosensibilisant plus spécifique des cellules cancéreuses (PpIX 5-ALA), et notamment gliales, la thérapie photodynamique cérébrale apparaît comme une thérapie additionnelle prometteuse, ayant potentiellement un effet synergique avec les traitements adjuvants recommandés.Dans le cadre de GBM opérables, la PDT intracavitaire a pu être évaluée par notre équipe lors d’un essai clinique de phase I (INDYGO), démontrant sa sécurité d’usage et confirmant des résultats oncologiques encourageants. L’évaluation de la dose de lumière optimale permettant de traiter plus en profondeur reste à réaliser. Un essai de phase II(DOSYNDIGO) y est dédié et est en cours de période d’inclusion.Toutefois, certaines lésions de par leur topographie ne peuvent être opérées sans engendrer des déficits neurologiques permanents et péjoratifs pour le pronostic du patient.L’absence de chirurgie d’exérèse initiale grève d’autant plus le pronostic ultérieur de la maladie en réduisant la période de survie sans progression et survie globale. Dans le cas des patients ne pouvant bénéficier d’une chirurgie d’exérèse, la PDT intracavitaire ne pouvait avoir lieu.C’est dans ce contexte que nous avons mené nos travaux de recherche en direction de la PDT interstitielle (iPDT). Ce traitement minimalement invasif consiste en l’introduction d’une ou plusieurs fibres optiques en conditions stéréotaxiques au sein de la tumeur ou à proximité immédiate afin de délivrer l’illumination requise sans réaliser de craniotomie ni de dissection du parenchyme cérébral. L’iPDT pourrait être indiqué pour les patients nouvellement diagnostiqués non opérables, mais aussi à la récidive. L’iPDT viendrait en complément des standards de soins, sans les modifier. Nous avons rapporté les données de la littérature concernant l’iPDT, puis nous avons proposé des données originales décrivant une procédure clinique standardisée basée sur un algorithme dosimétrique dédié, avant d’entrevoir un essai clinique de phase IHigh-grade primary brain tumors represent a major care issue. Indeed, the mostfrequent of these tumors, glioblastoma (GBM), have an appalling prognosis. Their mediansurvival is about 15 months when patients have undergone optimal excision surgery followedby the recommended adjuvant treatments of radiotherapy and chemotherapy. In spite of thesetreatments, recurrence is the rule, and most of the time close to the initial excision cavity. Newtechniques have been developed to improve local control of the tumor, such as the implantationof carmustine wafers in the surgical cavity. However, the benefit of this type of complementarytherapy is limited.It is in this context that the idea of applying photodynamic therapy (PDT) to GBM hasemerged. This treatment is based on the synchronous presence of three elements: aphotosensitizer molecule, oxygen and illumination at a specific wavelength triggering ametabolic cascade promoting the death of cancerous glial cells. Thanks to the development ofphotosensitizers specific to cancer cells (PpIX 5-ALA), especially glial cells, brain PDT appearsto be a promising additional therapy, potentially having a synergistic effect with gold-standardadjuvant treatments.In the context of operable GBM, intracavitary PDT has been evaluated by our team ina phase I clinical trial (INDYGO), demonstrating its safety and confirming encouragingoncological results. The evaluation of the optimal light dose for deeper treatment remains tobe done. A phase II trial (DOSYNDIGO) is dedicated to this and is currently in the inclusionperiod.However, some lesions, because of their topography, cannot be operated on withoutcausing permanent neurological deficits that are disabling for the patient prognosis. Theabsence of initial excisional surgery further compromises the prognosis of the disease byreducing the period of progression-free survival and total survival. In patients who could notbenefit from excisional surgery, this additional intra-cavity treatment could not take place. Thisis why we conducted our research work towards interstitial PDT. This involves introducing oneor more optical fibers under stereotactic conditions into the tumor or in its immediate vicinity inorder to deliver the required illumination without performing a craniotomy or dissecting thebrain parenchyma. This minimally invasive treatment represents a real opportunity for allpatients who cannot be operated on, either at the initial diagnosis of their GBM or at recurrence.This interstitial treatment would complement standard of care without modifying it. We reportedthe current data regarding iPDT available in the literature, then we proposed original data witha standardized clinical procedure based on a dedicated dosimetry algorithm, before lookingforward to a phase I clinical trial
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Walsh, David A. "Intracavity terahertz optical parametric oscillators." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/1713.
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This thesis describes the design and implementation of several novel, nanosecond pulsed, intracavity optical parametric oscillators for the generation of terahertz radiation. The application of the intracavity approach in the context of terahertz optical parametric oscillators has been demonstrated for the first time, and the pump wave energy required was thereby reduced by an order of magnitude. The terahertz wave was tunable from under 1THz up to 3THz with a free running linewidth of ~50GHz and pulse energies up to ~20nJ (pulses were a few nanoseconds in duration). The terahertz beam profile was of Gaussian shape and could be focussed down to 2.3 times the diffraction limited spot size (M² values of 2.3 and 6.7 in the components of the beam parallel and perpendicular to the silicon prism array output coupler respectively). Developments of this intracavity source with regard to the linewidth are also reported. Implementation of etalons in the optical (laser and OPO) cavities was shown to be a promising technique that brings the terahertz linewidth down below 1GHz (close to the transform limit of nanosecond pulses) while retaining the tuning range and beam characteristics of the free running system. Close to Fourier transform limited pulses were obtained (<100MHz linewidth) via an injection seeding technique, although with significantly increased system complexity. A deleterious effect caused by the mode beating of a multimode host laser was also discovered, in that sidebands were induced on the seeded downconverted wave. This has wider implications in the field of intracavity OPOs. Finally, quasi-phasematching techniques implementing periodically poled lithium niobate were investigated as a way to lower the downconversion threshold energy requirement (by collinear propagation of the optical waves), and also to extract the terahertz wave rapidly from the (highly absorbing in the terahertz region) lithium niobate crystal. The existence of two phasematching solutions arising from the bidirectionality of the grating vector was identified as a serious design constraint in the context of an OPO where either solution can build up from noise photons, and so prefers the solution with the lowest walkoff of the downconverted waves - possibly resulting in unextractable terahertz radiation. Quasi-phasematching with an orthogonal grating vector (with identical but opposite phasematching solutions) was demonstrated and cascaded downconversion processes observed and characterised. These cascaded processes are permitted by the collinearality of the optical waves and may allow efficiency improvements through overcoming the quantum defect limit. This research has resulted in four peer reviewed papers in respected journals, and the intracavity terahertz OPO has been licensed to a company who have commercialised the technology (M Squared Lasers, Glasgow).
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Facy, Olivier. "Optimisation des techniques de chimiothérapie intracavitaire." Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOMU07/document.
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Introduction. L’efficacité de la chimiothérapie intracavitaire dépend de la pénétration du produit au sein du péritoine (CHIP) ou de la plèvre. L’hyperthermie et l’hyperpression peuvent augmenter cette pénétration. Ce travail étudie leur effet intrapéritonéal, puis établit la méthode optimale pour les délivrer. L’étude de la faisabilité et de la tolérance d’une hyperpression intrapleurale est essentielle pour transposer ces bénéfices à la cavité thoracique. Méthodes. Quatre groupes de porcs ont reçu une CHIP ouverte avec de l’oxaliplatine à une concentration constante (150 mg/l) pendant 30 minutes en normothermie ou hyperthermie (42-43°C) ; et en pression atmosphérique ou hyperpression (25 cmH2O). Deux groupes ont reçu une procédure fermée en hyperthermie et hyperpression ou forte hyperpression (40 cmH2O). L’absorption systémique et tissulaire d’oxaliplatine a été étudiée. La tolérance d’une perfusion pleurale a été étudiée chez 21 porcs avec ou sans résection associée, avec ou sans chimiothérapie (cisplatine + gemcitabine), à divers niveaux de pression de 15 à 25 cmH2O. Résultats. L’hyperthermie augmente les concentrations de platine dans les surfaces viscérales (p=0.0014), alors que l’hyperpression l’augmente dans les surfaces viscérales et pariétales (respectivement p= 0.0058 et p= 0.0044). L’association des deux facteurs permet d’obtenir les concentrations les plus importantes dans le péritoine viscéral (p= 0.00001) et pariétal (p= 0.0003). Les concentrations obtenues lors des procédures fermées sont inférieures à celles obtenues en ouvert, même lorsque la pression atteint 40 cmH2O. Une chimiothérapie intrapleurale à 20 cmH2O sans résection associée est le niveau maximal toléré durant 60 minutes. Conclusion. Au cours d’une CHIP, l’hyperthermie augmente la pénétration d’oxaliplatine dans le péritoine viscéral, alors que l’hyperpression est efficace dans le péritoine viscéral et pariétal. Leur association est synergique et la procédure ouverte semble la meilleure pour la délivrer. Une chimiothérapie intrapleurale est faisable à 20 cmH2O dans ce modèleIntroduction. In order to achieve a good effect, chemotherapy drugs need to penetrate into the peritoneal (HIPEC) or pleural tissue. Hyperthermia and high-pressure may enhance this penetration. The aim of this study was to evaluate their peritoneal effect and to establish the best technique to it. A feasibility study of an intrapleural high-pressure was an essential step to export these effects to the thoracic space. Methods. Four groups of pigs underwent an open HIPEC with a constant concentration (150 mg/l) of oxaliplatin during 30 minutes either in normothermia, or in hyperthermia (42-43°C); and either with atmospheric pressure or with high-pressure (25 cmH2O). Two more groups underwent a closed procedure with hyperthermia and either high-pressure or very high-pressure (40 cmH2O). The systemic and tissue absorption of oxaliplatin were studied. The haemodynamic and respiratory tolerance of a pleural infusion was also tested in 21 pigs with and without associated resection; with and without chemotherapy infusion (cisplatin + gemcitabin) and at various levels of pressure (from 15 to 25 cmH2O). Results. Hyperthermia enhances the concentrations of platinum in visceral surfaces (p=0.0014), whereas high-pressure enhances it both in visceral and in parietal surfaces (p= 0.0058 and p= 0.0044, respectively). Their association obtains the highest concentrations both in the visceral (p= 0.00001) and the parietal peritoneum (p= 0.0003). The concentrations obtained during closed procedure are lower than those achieved with the open technique, even with 40 cmH2O of pressure. A 60-minutes intrapleural chemotherapy perfusion with 20 cmH2O of pressure without any lung resection was the maximal tolerated level. Conclusion. During HIPEC, hyperthermia improves the penetration of oxaliplatin in the visceral peritoneum, whereas high-pressure is effective in both peritoneal surfaces. Their association is synergic and the open technique seems to be the best one to deliver it. An intrapleural chemotherapy with a 20 cmH2O pressure is feasible in this model
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Hammond, Thomas John. "Intracavity generation of high order harmonics." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/39747.
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The goal of this work is the generation of extreme ultraviolet (EUV) radiation from a laser based source. To this end, we use high harmonic generation (HHG) to convert the near infrared output of a mode-locked Ti:Sapphire laser oscillator to the EUV. The requirement for HHG is a high peak intensity (>10¹³ W/cm²), which can be met by external amplification of the laser output. The method of amplification chosen for this work is a femtosecond enhancement cavity (fsEC), which stores and amplifies the output of a femtosecond mode-locked Ti:Sapphire laser by greater than a factor of 900 while maintaining the original repetition rate of 66 MHz. The design, benefits, and limitations of using a fsEC are discussed. The EUV light is created by the interaction of the amplified light with xenon gas delivered to the fsEC focus. The strong intracavity field leads to xenon plasma generation with detrimental effects on the HHG process, where it is shown that HHG is sensitive to the xenon gas and plasma dynamics. Methods of minimizing the plasma density and maximizing the EUV amplitude are discussed. The EUV is coupled out of the cavity, and up to the thirteenth harmonic (61 nm) of the laser is observed. The relative amplitudes of the different quantum trajectories generating the harmonics are calculated theoretically, and compared to experiment. The generated power of the eleventh harmonic (72 nm) is estimated to be 30μW, with a measured outcoupled power of 1.1μW. The relative intensity noise is also measured, with a cumulative root-mean-square (RMS) noise of <1.2% over 100 Hz - 100 kHz bandwidth. In comparison to other laser based HHG systems, while the EUV flux is similar, the cumulative RMS noise is an order of magnitude lower.
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Robledo, Victor Joel Pinto. "Intracavity frequency modulation of modelocked lasers." Thesis, University of Essex, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386032.
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James, Glenn Edward. "Models of intracavity of frequency doubled lasers." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/30499.
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Wang, Jing-Yi. "Nonlinear processes in intracavity second harmonic generation." Doctoral thesis, Universite Libre de Bruxelles, 1996. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212351.
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Gawali, Sandeep Babu. "Intracavity spatial filtering in broad area semiconductor laser." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/670567.
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Semiconductor lasers in high-power regime typically manifest a poor beam quality due to its asymmetric beam divergence and its large beam quality factor (M2). The emission along one of the transverse directions (slow axis) is typically multimode while being single mode in the perpendicular direction (fast axis). Due to the multimode emission and the absence of any intrinsic mode selection mechanism, the beam quality of broad area semiconductor (BAS) laser is degraded. In this work, we demonstrate that, by means of spatial filtering technique, the beam quality may be improved along the lateral direction (slow axis). For the filtering purpose, we propose the use of photonic crystal (PhC) as the spatial filtering element. The PhC offers an advantage in terms of its compact size, which allows miniaturization of the device. The successful implementation of this scheme could lead to monolithic integration, with the PhC directly integrated between the front facet of the semiconductor material and the laser cavity mirror. The PhCs were fabricated on N-BK7 glass substrate using tightly focused femtosecond Bessel beam. Two different PhC with different parameters were used in the experiment. The filtering of the PhC appears due to the deflection of selected components of the beam out of the propagation direction, using the Laue configuration.
Since the PhC operates only in the near field plane, the access to this plane for the experimental testing of the idea introduces a technological difficulty in such small devices.We followed a simplified approach using an extended cavity configuration, which mimics the action of the compact cavity. The advantage of the extended cavity setup is that it allows testingdifferent filtering geometries in the same setup. The extended cavity was built using AR coated single emitter BAS laser, fast axis collimator, a double 4f lens system, and an external mirror with reflectivity of 4%. This extended cavity allows implementing two different techniques, i.e. an intracavity slit and a photonic crystal in the same setup. The cavity was characterized by measuring the output power, beam quality factor (M2), spectrum, and near/far field laser profiles.
Before testing the action of PhC, we tested the conventional spatial filtering using intracavity slit placed in the far field and acting on the beam in the lateral direction by blocking the higher angular components of the beam. The output beam from the external cavity was characterized by measuring the M2 along the slow axis and calculating the brightness of the beam. We demonstrate an enhancement in the brightness by factor of two compared to the unfiltered beam situation. We further evaluated the effect of the reflectivity of the feedback mirror on the output power and spatial profile of the beam. The filtering action of the PhCs was characterized using the same extended cavity configuration. In this configuration an enhancement of the brightness by a factor between 1.3 and 1.5 was demonstrated for the different crystals. In addition, we used another emitter with longer cavity length and transverse width and with 4 % coating on the front facets.
The experimental results obtained using intracavity slit and PhC were compared with the numerical results obtained froma numerical model of broad area laser created to simulate the action of spatial filtering using either the intracavity slit or the PhC. Both results showed a good agreement between the experiments and the numerical results.The numerical code was used to further optimize the brightness enhancement by simulating different filtering geometries.Los láseres de semiconductor en régimen de alta potencia suelen manifestar una mala calidad del haz debido a su divergencia asimétrica del haz y a su elevado factor de calidad del haz (M2). La emisión a lo largo de una de las direcciones transversales (eje lento) es típicamente multi-modo mientras que es mono-modo en la dirección perpendicular (eje rápido). Debido a la emisión multi-modo y a la ausencia de cualquier mecanismo intrínseco de selección de modo, la calidad del haz del láser semiconductor de área amplia (BAS) se degrada. En este trabajo demostramos que, mediante la técnica de filtrado espacial, la calidad del haz puede mejorarse en la dirección lateral (eje lento). Para filtrar el haz, proponemos el uso de cristal fotónico (PhC) como elemento de filtrado espacial. El PhC ofrece una ventaja en términos de su tamaño compacto, que permite la miniaturización del dispositivo. La demostración de la posibilidad de usar este esquema podría conducir a una integración monolítica, con el PhC directamente integrado entre la cara frontal del material semiconductor y el espejo de la cavidad del láser. Los PhC se fabricaron en un sustrato de vidrio N-BK7 usando un haz de Bessel de femtosegundos fuertemente focalizado. En el experimento se utilizaron dos PhC diferentes con diferentes parámetros. El filtrado de los PhC aparece debido a la desviación de componentes seleccionados del haz fuera de la dirección de propagación, usando la configuración Laue. Dado que el PhC opera sólo en el plano del campo cercano, el acceso a este plano para el ensayo experimental de la idea introduce una dificultad tecnológica en dispositivos tan pequeños. Hemos seguido un enfoque simplificado utilizando una configuración de cavidad extendida, que imita la acción de la cavidad compacta. La ventaja de la configuración de la cavidad extendida es que permite probar diferentes geometrías de filtrado en la misma configuración. La cavidad extendida se construyó utilizando un láser BAS de un solo emisor con recubrimiento anti-reflectante, un colimador de eje rápido, un sistema de lentes dobles 4f y un espejo externo con una reflectividad del 4%. Esta cavidad extendida permite la implementación de dos técnicas diferentes, una rendija intra-cavidad y un cristal fotónico, en la misma configuración. La cavidad se caracterizó midiendo la potencia de salida, el factor de calidad del haz (M2), el espectro y los perfiles del láser de campo cercano y lejano. Antes de probar la acción del PhC, probamos el filtrado espacial convencional utilizando una rendija intra-cavidad situada en el campo lejano y actuando sobre el haz en dirección lateral bloqueando los componentes angulares superiores del haz. El haz de salida de la cavidad externa se caracterizó midiendo el M2 a lo largo del eje lento y calculando el brillo del haz. Demostramos un aumento del brillo por un factor de dos en comparación con la situación del haz sin filtrar. Evaluamos además el efecto de la reflectividad del espejo de retroalimentación en la potencia de salida y el perfil espacial del haz. La acción de filtrado de los PhC se caracterizó utilizando la misma configuración de cavidad extendida. En esta configuración se demostró un aumento del brillo en un factor entre 1,3 y 1,5 para los diferentes cristales. Además, se utilizó otro emisor con una longitud de cavidad más larga y una anchura transversal y con un recubrimiento del 4 % en las caras frontales. Los resultados experimentales obtenidos mediante la rendija intra-cavidad y el PhC se compararon con los resultados numéricos obtenidos a partir de un modelo numérico de láser de área amplia creado para simular la acción del filtrado espacial utilizando la rendija intra-cavidad o el PhC. Ambos resultados mostraron una buena concordancia entre los experimentos y los resultados numéricos. El código numérico se utilizó para optimizar aún más el aumento del brillo simulando diferentes geometrías de filtrado
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Eilers, Gerriet, Anders Persson, Cecilia Gustavsson, Linus Ryderfors, Emad Mukhtar, Göran Possnert, and Mehran Salehpour. "The Radiocarbon Intracavity Optogalvanic Spectroscopy Setup at Uppsala." Uppsala universitet, Tillämpad kärnfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-202651.
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Accelerator mass spectrometry (AMS) is by far the predominant technology deployed for radiocarbon tracer studies. Applications are widespread from archaeology to biological, environmental, and pharmaceutical sciences. In spite of its excellent performance, AMS is expensive and complicated to operate. Consequently, alternative detection techniques for 14C are of great interest, with the vision of a compact, user-friendly, and inexpensive analytical method. Here, we report on the use of intracavity optogalvanic spectroscopy (ICOGS) for measurements of the 14C/12C ratio. This new detection technique was developed by Murnick et al. (2008). In the infrared (IR) region, CO2 molecules have strong absorption coefficients. The IR-absorption lines are narrow in line width and shifted for different carbon isotopes. These properties can potentially be exploited to detect 14CO2, 13CO2, or 12CO2 molecules unambiguously. In ICOGS, the sample is in the form of CO2 gas, eliminating the graphitization step that h is required in most AMS labs. The status of the ICOGS setup in Uppsala is presented. The system is operational but not yet fully developed. Data are presented for initial results that illustrate the dependence of the optogalvanic signal on various parameters, such as background and plasma-induced changes in the sample gas composition.
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Bonner, Gerald Michael. "Thermal and spectral effects in intracavity Raman lasers." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=22403.
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Stimulated Raman scattering is a convenient way to extend the spectral coverage of well-established solid-state laser sources. In an intracavity Raman laser, a Raman crystal is placed inside the cavity of the fundamental laser, and the output frequency is red-shifted by an amount corresponding to a vibrational energy level of the Raman crystal. Despite the physical simplicity of these lasers, the interactions between the various optical fields are complex, and must be understood in order to realise efficient, high power operation. This thesis presents a detailed investigation of thermal and spectral effects in CW intracavity Raman lasers. A disk geometry was used to reduce the thermal lens in the laser gain crystal, thereby permitting more flexible cavity design. This facilitated experiments to probe and control the thermal and spectral effects. Diamond was assessed as a potential Raman crystal with weak thermal lensing. The optical losses in several crystals were measured and while some low loss material was identified, the supply of such material is not yet reliable. The thermal lens in a common Raman crystal, BaWO4, was measured and found to be negative and astigmatic. Using a coupled cavity configuration, experiments were performed to disentangle the effects of the thermal lenses in the laser gain and Raman crystals. This information was used to re ne the cavity design and improve the performance of the laser in a more systematic way than would otherwise have been possible. It was shown that Raman lasers using laser gain disks can provide comparable performance to rod-based systems. The first ever detailed investigation into spectral broadening in CW crystalline intracavity Raman lasers was undertaken using a combination of theory and experiment. The use of etalons to limit the broadening was investigated and it was found that these could improve the spectral brightness of the laser.
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Parrotta, Daniele Carmine. "Raman lasers intracavity-pumped by semiconductor disk lasers." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24895.
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Semiconductor disk lasers (SDLs) are efficient and commercially attractive devices as they can emit several Watts in continuous-wave (cw) operation, with good beam quality, low noise and great wavelength flexibility. SDL fundamental emission ranges from red to mid-infrared, while ultraviolet and other visible wavelength can be obtained via harmonic generation. This research shows that Raman conversion is an efficient way to extend the spectral coverage of well-established SDLs. The first experimental work consisted in the demonstration of a KGW Raman laser intracavity-pumped by a 1055 nm InGaAs SDL for laser emission at ~1.14 µm. This work represents the first Raman conversion of an SDL ever reported. Output power up to 0.8 W, broad wavelength tunability and cascaded Raman conversion (with low output coupling) were observed. The following experiment consisted in using synthetic single-crystal diamond as the Raman medium. In the last few years diamond has become a prominent Raman crystal as it provides high Raman gain, large Stokes shift and unrivalled thermal conductivity. A diamond Raman laser intracavity-pumped by an InGaAs SDL emitted up to 4.4 W at 1228 nm and was tuned from 1209-1256 nm. With an optical conversion efficiency exceeding 14%, this laser rivals the optical efficiencies of other cw Raman lasers and, perhaps more importantly, SDLs with direct emission at ~1.2 µm. Orange emission, with maximum output power of 1.5 W at 614 nm and wavelength tuning from 604.5-619.5 nm, was obtained via intracavity second harmonic generation in the Raman laser cavity. Raman conversion of a red-emitting GaInP SDL using a synthetic diamond crystal is also reported. As GaInP SDLs are less efficient than InGaAs SDLs, Raman threshold was more difficult to achieve, despite the Raman gain increasing for decreasing wavelengths. Nonetheless, Raman conversion in the deep red was observed, with output power of few tens of ~W, due to the low output coupling for the Raman laser, and tunable emission from 738-748 nm. This work is still at an early stage, so higher output power and enhanced laser efficiency may be achieved in future experiments.
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Leal, Luis Carlos Avila. "Intracavity absorption spectroscopy with Er3+-doped fiber lasers." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7371.
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Mestrado em Engenharia FísicaEspectroscopia de absorção de intracavidade com um laser de banda larga de fibra dopada com Er3+ é aplicada para medidas resolvidas no tempo de moléculas de CO2 revelando informações quantitativas sobre a concentração do gás exalado na respiração humana. A gama espectral das medições estende-se de 1.52 μm – 1.61 μm através da deslocação da lente de intracavidade. Com um laser pulsado aplicado nesta experiência, a sensibilidade à absorção corresponde a um comprimento do percurso de absorção efectiva de 6 km assumindo que a cavidade está completamente preenchida com a amostra. O aumento da sensibilidade é alcançada através da construção de um laser de configuração em anel unidirecional. O comprimento do percurso de absorção efectiva é aumentado por um factor de três comparando com uma configuração linear com o mesmo comprimento da cavidade.
Intracavity absorption spectroscopy with a broadband Er3+-doped fiber laser is applied for time-resolved measurements of CO2 molecules revealing quantitative information about the gas concentration in exhaled human breath. The spectral range of measurements extends from 1.52 to 1.61 μm by moving an intracavity lens. With a pulsed laser applied in this experiment, the sensitivity to absorption corresponds to an effective absorption path length of 6 km assuming the cavity is completely filled with the sample. Sensitivity enhancement is achieved by employing an unidirectional ring laser. The effective absorption path length is enhanced by a factor of three compared to a linear configuration with the same cavity length.
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Goodell, Brian Carpenter, and Brian Carpenter Goodell. "Probing Intracavity Plasma Dynamics with Higher-Order Transverse Modes." Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/625686.
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Extreme ultraviolet (XUV) frequency combs exhibit promise for enabling high-precision spectroscopic measurements of myriad chemical species for the first time. Coherent XUV radiation can be generated through high harmonic generation (HHG) in femtosecond enhancement cavities. HHG efficiency is limited by nonlinear phase shifts induced by residual intracavity plasma. The goal of this work is to gain insight regarding plasma dynamics in order to allay the detrimental effects of plasma interactions. Our approach is to conduct simulations of cavity pump-probe experiments by probing with higher-order transverse modes. We propose methods for estimating spatial plasma profiles, gas jet velocities, and the plasma recombination coefficient based on measurements of plasma-induced phase shifts. Beam distortion due to plasma interaction is analyzed and used as another reference for plasma dynamics.
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Witonsky, Scott Kenneth 1975. "Kinetics and dynamics measured using IntraCavity Laser Absorption Spectroscopy." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8045.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2002.Vita.
Includes bibliographical references (p. 133-138).
IntraCavity Laser Absorption Spectroscopy (ICLAS) is a high-resolution, high sensitivity spectroscopic method capable of measuring line positions, linewidths, lineshapes, and absolute line intensities with a sensitivity that far exceeds that of a traditional multiple pass absorption cell or Fourier Transform spectrometer. From the fundamental knowledge obtained through these measurements, information about the underlying spectroscopy, dynamics, and kinetics of the species interrogated can be derived. The construction of an ICLA Spectrometer will be detailed, and the measurements utilizing ICLAS will be discussed, as well as the theory of operation and modifications of the experimental apparatus. Results include: i) Line intensities and collision-broadening coefficients of the A band of oxygen and previously unobserved, high J, rotational transitions of the A band, hot-band transitions, and transitions of isotopically substituted species. ii) High-resolution (0.013 cm-1) spectra of the second overtone of the OH stretch of trans-nitrous acid recorded between 10,230 and 10,350 cm-1. The spectra were analyzed to yield a complete set of rotational parameters and an absolute band intensity, and two groups of anharmonic perturbations were observed and analyzed. These findings are discussed in the context of the contribution of overtone-mediated processes to OH radical production in the lower atmosphere.
(cont.) iii) The implementation of Correlated Double Sampling (CDS) for time-resolved studies of CN fragments generated by the excimer laser photolysis of acrylonitrile. iv) The extension of ICLAS to study the kinetics of a test system. Nitrosyl hydride, HNO, was reacted with oxygen in a flow cell, and the subsequent chemistry was monitored using an electronic transition of HNO. Analysis of the rate equations and time integrated measured signal yielded a preliminary value for the rate constant of the reaction, HNO + 02 [right arrow] products.
by Scott Kenneth Witonsky.
Ph.D.
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Severo, Luiz Carlos. "Colonizacao intracavitaria pulmonar por aspergillus niger : analise de suas peculiaridades." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 1987. http://hdl.handle.net/10183/1422.
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Trezentos pacientes portadores de colonização intracavitária pulmonar (pelos exames soro lógico e/ou tecidual) foram investigados num período de 10 anos. Os casos foram classificados como: Aspergillus fumigatus (246 casos); Ao niger (21 casos); A. flavus (7 casos); Pseudallescheria boydii (1 caso); colonização fúngica não especificada (21 casos) e colonização actinomicética (4 casos). os grupos A. niger (çasos)e A. fumigatus (controles) foram comparados a respeito de variáveis clínicas e laboratoriais, por serem os mais freqUentes e pela pobreza da literatura sobre A. niger. Esta análise mostrou associações estatisticamente significativas com o A. niger para;sexo masculino (Razão de Chances = 3,28; p <0,05); infecção nosocomial, ocorrendo em hospitais de conservação precária (RC = 150,8; p< 0,001); tuberculose ativa (RC = 8,03; P <0,001); diabete mélito tipo 11 (RC = 10,67; p
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Kane, Daniel John. "Intracavity optical parametric oscillators based on orientation-patterned gallium arsenide." Thesis, University of Strathclyde, 2016. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27499.
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Elejalde, Untzizu. "Intracavity detection of chemicals in the liquid phase with semiconductor lasers." Thesis, University of Strathclyde, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487865.
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Near infrared spectroscopic techniques have always played an important role in the monitoring of chemical processes. In particular the use of near infrared absorption spectroscopy is used as a standard laboratory method of determining the chemicals present within a given sample. Conventional near IR spectroscopy generally does not have a high sensitivity for trace chemical detection, or are not well suited for on-line, real-time, reaction monitoring of liquid species at very low concentrations and for bio-molecule detection. With the advent of lab-on-a-chip systems and micro-fluidic chemistry there is an increasing requirement for detection methods in which the sample is not removed from the system.
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Rizzuto, Cristiana. "Identificazione dell'attivazione del fascio di HIS nei segnali intracavitari in tachicardia sopraventricolare da rientro nodale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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La tachicardia sopraventricolare da rientro nel nodo atrioventricolare (AVNRT) è la forma più comune di tachicardia parossistica sopraventricolare riscontrata nella pratica clinica, costituendone circa i due terzi dei casi, con incidenza maggiore nei giovani adulti e nel sesso femminile. Il trattamento d’elezione per la risoluzione definitiva dell’AVNRT attualmente è rappresentato dall’ablazione transcatetere a radiofrequenza della via lenta. La via lenta è situata tra l'ostio del seno coronarico e l'anulus tricuspidale, posizione che garantisce un maggiore margine di sicurezza, con riduzione dei casi di blocco atrioventricolare completo inferiori all’ 1 %, poiché più distante dal nodo atrio-ventricolare (AV) compatto e dal fascio di His rispetto alla via rapida, che in passato costituiva il target dell’ablazione con complicazioni nel 20% dei casi. Sebbene il rischio di sviluppare un blocco AV completo si sia notevolmente ridotto con il cambio del target di ablazione, nei rari casi in cui ancora oggi si verifica può essere necessario l’impianto di un pacemaker. Nel seguente progetto di tesi è stato sviluppato un algoritmo di elaborazione dei segnali intracavitari, registrati durante lo studio elettrofisiologico, in grado di identificare con chiarezza l’attivazione del fascio di His nel segnale intracavitario registrato dal catetere posto in prossimità del fascio, anche in situazioni che non lo consentono a causa dell’influenza delle attivazioni atriali e ventricolari. Ciò consente di individuare con maggiore stabilità un punto di protezione della struttura sensibile dal quale occorre mantenere una certa distanza durante l’erogazione dell’energia a radiofrequenza. Il risultato ottenuto rappresenta il primo passo di un approccio, che potrebbe essere ulteriormente ottimizzato in sviluppi futuri, contribuendo ad una significativa riduzione del rischio in termini di sviluppo di blocco atrioventricolare completo durante la procedura.
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Awada, Mouhamad. "Matériaux calixaréniques pour la catalyse." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAF021.
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La réalisation d'une transformation chimique dans un espace confiné constitue pour les chimistes molécularistes un véritable défi. Des recherches récentes ont montré que des réactions se déroulant dans une poche ou une cavité moléculaire étaient de nature à engendrer des sélectivités nouvelles et faciliter des réactions thermodynamiquement défavorables. L'association métal-cavité permet également le déroulement de processus catalytiques en milieu aqueux, dès lors que la cavité a été rendue hydrosoluble.L’objectif de cette thèse était de préparer des ligands originaux intégrant une ou plusieurs cavités moléculaires de type calix[4]arène et d’en étudier les propriétés complexantes. L’ensemble des calixarènes synthétisés sont porteurs d’un ou plusieurs groupes PPh2 directement liés au bord supérieur du macrocycle. Plusieurs types de molécules ont été préparées : (i) des bis-calixarènes formant, après complexation, des métallo-capsules; (ii) des calixar!ène-diphosphines adaptées à la formation de complexes bimétalliques dans lesquels les centres métalliques sont placés entre deux coquilles se faisant face. L’activité catalytique de certains de ces métallo-capsules est jusqu’à 40 fois supérieurs à celle observé pour un catalyseur classique.La dernière partie de cette thèse a pour objectif de mettre à la disposition des spécialistes de la chimie des surfaces des phosphacalixarènes originaux destinés à la confection de supports solides P(III)-fonctionnalisés et donc de nouveaux catalyseurs supportésThe realization of a chemical transformation in a confined space is for molecularist chemists a challenge. Recent research has shown that reactions occurring in a pocket or a molecular cavity were such as to generate selectivities and facilitate new thermodynamically unfavorable reactions.The metal-cavity association allows also the course of catalytic processes in aqueous medium, when the cavity has been made water soluble.The objective of this thesis was to prepare original ligands incorporating one or more cavities of molecular type calix[4]arene and to study their complexing properties. All the synthesized calixarenes are carriers of one or more groups PPh2 directly related to the upper rim of the macrocycle.Several types of molecules were prepared: (i) bis-calixarenes forming, after complexation, metallocapsules, (ii) calixarene-diphosphines suitable for the formation of bimetallic complexes in which the metal centers between two shells are placed facing each other. The catalytic activity of some of these metallo-capsules is 40 times higher than that observed for a conventional catalyst.The last part of this thesis aims to make available experts in surface chemistry of the original phosphacalixarenes for making solid supports P (III)-functionalized and thus new supported catalysts
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Astoul, Philippe. "Immunotherapie intracavitaire : administration intrapleurale d'interleukine-2 recombinante dans la traitement des cancers pleuraux." Aix-Marseille 2, 1994. http://www.theses.fr/1994AIX22961.
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Shrestha, Jyoti Chandra [Verfasser]. "Theoretical and experimental study of intracavity laser absorption spectroscopy / Jyoti Chandra Shrestha." Kassel : Universitätsbibliothek Kassel, 2015. http://d-nb.info/1069569550/34.
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Townshend, Nichola. "Developments in Raman spectrometry and intracavity laser absorption spectrometry for quantitative analysis." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25752.
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Medhi, Gautam. "Intracavity laser absorption spectroscopy using quantum cascade laser and Fabry-Perot interferometer." Doctoral diss., University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4800.
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Intracavity Laser Absorption Spectroscopy (ICLAS) at IR wavelengths offers an opportunity for spectral sensing of low vapor pressure compounds. We report here an ICLAS system design based on a quantum cascade laser (QCL) at THz (69.9 micrometers]) and IR wavelengths (9.38 and 8.1 micrometers]) with an open external cavity. The sensitivity of such a system is potentially very high due to extraordinarily long effective optical paths that can be achieved in an active cavity. Sensitivity estimation by numerical solution of the laser rate equations for the THz QCL ICLAS system is determined. Experimental development of the external cavity QCL is demonstrated for the two IR wavelengths, as supported by appearance of fine mode structure in the laser spectrum. The 8.1 micrometers] wavelength exhibits a dramatic change in the output spectrum caused by the weak intracavity absorption of acetone. Numerical solution of the laser rate equations yields a sensitivity estimation of acetone partial pressure of 165 mTorr corresponding to ~ 200 ppm. The system is also found sensitive to the humidity in the laboratory air with an absorption coefficient of just 3 x 10[super -7] cm[super -1] indicating a sensitivity of 111 ppm. Reported also is the design of a compact integrated data acquisition and control system. Potential applications include military and commercial sensing for threat compounds such as explosives, chemical gases, biological aerosols, drugs, banned or invasive organisms, bio-medical breath analysis, and terrestrial or planetary atmospheric science.ID: 030646266; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2011.; Includes bibliographical references (p. 87-95).
Ph.D.
Doctorate
Physics
Sciences
Physics
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Chitnalah, Ahmed. "Dispositif ultrasonore pour hyperthermie intracavitaire : Applications envisagées aux traitements des tumeurs cancereuses prostatiques ou vaginales." Nancy 1, 1990. http://docnum.univ-lorraine.fr/public/SCD_T_1990_0422_CHITNALAH.pdf.
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Le travail présenté dans cette thèse concerne l'étude, la réalisation et la caractérisation des sondes ultrasonores pour le traitement des tumeurs cancéreuses vaginales, prostatiques ou du rectum; par hyperthermie intra cavitaire. La première partie présente l'approche théorique des caractéristiques des différentes céramiques utilisées. Nous avons étudié le rendement, l'impédance électrique et le circuit électrique équivalent. Un algorithme, utilisant la méthode d'intégration de Simpson, permet le calcul numérique du diagramme de rayonnement. La deuxième partie présente la méthodologie et les résultats expérimentaux. La distribution spatiale de l'intensité acoustique dans l'eau et le glycérol a été mesurée par un détecteur piézo-électrique de petite taille. Ainsi la directivité et la profondeur de pénétration des faisceaux ultrasonores ont été déterminées. Il est montré qu'une vobulation permet d'améliorer l'homogénéité du faisceau sur toute son ouverture. Ainsi ont été étudiées les variations des gradients thermiques dans l'espace, en fonction du temps et de la puissance d'émission. Le refroidissement des applicateurs en surface permet de produire un échauffement en profondeur.
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Schaar, Joseph Eden. "Terahertz sources based on intracavity parametric frequency down-conversion using quasi-phase-matched gallium arsenide /." May be available electronically:, 2009. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Spasic, Estelle. "Dosimétrie in vivo intracavitaire basée sur la luminescence stimulée optiquement de l'Al2O3 : C dédiée à la curiethérapie." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0270/document.
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La curiethérapie est une technique ancienne utilisant des sources scellées de faible ou moyenne énergie, toujours pertinente aux plans thérapeutique et économique et toujours en évolution (e.g. curiethérapie à Haut Débit de Dose (HDD)). Cette modalité de traitement permet de délivrer une forte dose d'irradiation dans un volume-cible limité, et permet de minimiser le risque de cancer radio-induit en préservant les Organes à Risques (OAR). Cependant, elle génère des gradients de dose élevés rendant la dosimétrie in vivo délicate à mettre en oeuvre. Les écarts constatés entre doses délivrées et prescrites sont ainsi fréquemment supérieurs à l'écart maximal toléré par la réglementation (± 5%) en usage pour la radiothérapie externe conventionnelle et rendue obligatoire en France par décret depuis 2011. Ce travail de thèse s'est déroulé dans le cadre du projet ANR-TECSAN INTRADOSE et exploite les acquis technologiques antérieurs démontrés à l'issue du projet Européen MAESTRO et du projet ANR-TECSAN CODOFER, en particulier une instrumentation RL/OSL (Radioluminescence - Optically Stimulated Luminescence) multivoies réalisée et validée au plan préclinique dans le cadre du projet MAESTRO. Le projet INTRADOSE a pour objectif de démontrer la faisabilité d'une Dosimétrie In Vivo (DIV) intracavitaire par cathéter dosimétriques à fibres optiques et cristaux d'alumine Al2O3:C dans le but d'améliorer la sécurité des patients traités par Curiethérapie HDD. Ce nouveau type de détecteur permet de mesurer une distribution de doses (mulitpoints) proche des OAR, il présente un petit diamètre (The brachytherapy is an old technique using sealed radioactive sources of low or average energy. This technique is still therapeutically and economically relevant today and always evolving (e.g. High Dose Rate (HDR) brachytherapy). This treatment enables to deliver a high dose of irradiation in a limited tumoral volume and enables to minimize the risk of radiation-induced cancer as preserving the Organs at Risks (OAR). However, this technique generates high dose gradients, which makes in vivo dosimetry difficult to implement. Hence, the deviations observed between doses delivered and prescribed are often up to the maximal deviation tolerated by the nuclear safety regulations (± 5%) in conformational radiotherapy. Those regulations have been made mandatory in France since 2011. This thesis has been done within the framework of the ANR-TECSAN INTRADOSE project and is based on the past technological benefits demonstrated during the MAESTRO European project and the ANR-TECSAN CODOFER project, in particular a RL/OSL multichannel instrumentation (Radioluminescence - Optically Stimulated Luminescence) made and validated in preclinical evaluation during the MAESTRO project. The purpose of the INTRADOSE project is to demonstrate the feasibility of the intracavitary In Vivo Dosimetry (IVD) by dosimetric catheter using optical fibers and alumina crystals Al2O3:C with the aim of improving the safety of patients treated by HDR brachytherapy. This new probe enables to measure a dose distribution (several points) close to the OAR, it offers a little diameter (
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Deppe, Bastian [Verfasser], and Christian [Akademischer Betreuer] Kränkel. "High-intracavity-power thin-disk laser for the alignment of molecules / Bastian Deppe ; Betreuer: Christian Kränkel." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1186891238/34.
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Leo, Qiyuan Hu, and Pontus Jäderholm. "Transmission characterization of fiber Bragg gratings arrays for intracavity spectral control of a 1.5 micrometer fiber laser." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297813.
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This thesis aims to investigate whether a fiber Bragg grating array (FBGA) can be designed to reduce the bandwidth of light from a 1.5 µm fiber laser while the distances between the fiber Bragg gratings are in the 10-20 cm range. The results from simulations show that for FBGA with multiple cavities, small changes in cavity length impact transmission drastically. For FBGA consisting of only two fiber Bragg gratings, the quality of the laser cavity's spectrum is improved, as the peak width is reduced and stability is increased. The conclusions of the experiments and the simulations are that FBGA with a single cavity gives best performance. For future studies, if higher computational power and production capabilities are available, an in depth analysis of a multi cavity FBGA could be conducted.
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Fan, Li. "Tunable High-Power High-Brightness Vertical-External-Cavity Surface-Emitting Lasers and Their Applications." Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/195755.
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The extraction of high power with high beam quality from semiconductor lasers has long been a goal of semiconductor laser research. Optically pumped vertical-external-cavity surface-emitting lasers (VECSELs) have already shown the potential for their high power high brightness operation. In addition, the macroscopic nature of the external cavity in these lasers makes intracavity nonlinear frequency conversion quite convenient. High-power high-brightness VECSELs with wavelength flexibility enlarge their applica-tions. The drawbacks of the VECSELs are their poor spectral characteristics, thermal-induced wavelength shift and a few-nm-wide linewidth.The objective of this dissertation is to investigate tunable high-power high-brightness VECSELs with spectral and polarization control. The low gain and microcavity reson-ance of the VECSEL are the major challenges for developing tunable high-power VECSELs with large tunability. To overcome these challenges, the V-shaped cavity, where the anti-reflection coated VECSEL chip serves as a folding mirror, and an extremely low-loss (at tuned wavelength) intracavity birefringent filter at Brewster's angle are employed to achieved the high gain, low-loss wavelength selectivity and the elimination of microcavity. This cavity results in multi-watt TEM00 VECSELs with a wavelength tuning range of 20~30 nm about 975 nm. Also the longitudinal mode discrimination introduced by birefringent filter makes the linewidth narrow down to 0.5 nm. After the tunable linearly polarized fundamental beam is achieved, the tunable blue-green VECSELs are demonstrated by using type I intracavity second-harmonic generation. The spectral control of VECSELs makes it possible to apply them as an efficient pump source for Er/Yb codoped single-mode fiber laser and to realize the spectral beam combining for multi-wavelength high- brightness power scaling.In this dissertation, theory, design, fabrication and characterization are presented. Rigorous microscopic many-body theory of the quantum well gain, based on semiconductor Bloch equations and k.p theory, is introduced. The closed loop design tool based on this theory is not only used to design the VECSEL structure, but also used as a precise on-wafer diagnostics tool by the experiment/theory comparison of the photo-luminescence. The characterization of the wafer shows that the modeling is in good agreement with the measured results.The VECSEL high power high brightness performance relies on the fabrication of the chip. The fabrication method of the VECSEL chip, which provides the optically smooth surface and good heat dissipation, is presented. The anti-reflection coating on the chip surface can significantly improve the slope efficiency of VECSEL when high reflectivity output coupler is used. Over 12-W VECSEL cw output power with 43 % slope efficiency is demonstrated at 0 oC. A beam quality factor (M^2 factor) of 1.75 is obtained at 11 W output power.
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Ahmad, Mahmoud Mohamed Mahmoud [Verfasser]. "Highly Sensitive Sensor Based On Intracavity Laser Absorption Spectroscopy By Means of Relative Intensity Noise / Mahmoud Mohamed Mahmoud Ahmad." Kassel : Universitätsbibliothek Kassel, 2011. http://d-nb.info/1009650874/34.
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Souza, Fernando Sergio Oliva de. "Aspectos tecnicos da cateterização do seio coronariano baseado no componente atrial do eletrograma intracavitario durante o procedimento de implante de marcapasso biventricular." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311523.
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Orientador: Orlando Petrucci JuniorTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: A estimulação elétrica biventricular apresenta bons resultados no tratamento da insuficiência cardíaca congestiva refratária em portadores de cardiomiopatia dilatada com distúrbios de condução interventricular. OBJETIVO: Apresentar proposição utilizando técnica original simplificada para o implante de eletrodo de estimulação ventricular esquerda epicárdica, baseado na anatomia radiológica e no eletrograma intracavitário,enfatizando o componente atrial, demonstrando o resultado, complicações, ressaltando tempo total de utilização de fluoroscópio. CASUÍSTICA E MÉTODO: De Outubro de 2001 a Março de 2007 foram realizados 234 implantes de marca-passo biventricular em pacientes previamente selecionados, utilizando-se anatomia radiológica e observação de eletrograma intracavitário, dando-se prioridade ao componente atrial, demonstrando a taxa de sucesso, complicações e tempo total de utilização de radioscopia. RESULTADOS: O implante do sistema, utilizando-se a estimulação do ventrículo esquerdo via seio coronariano não foi possível em 19(8,1%) pacientes. Em 30(12,8%) pacientes foram observadas dificuldades na canulação do óstio coronário e em 52(22%) pacientes observaram-se dificuldades de progressão do eletrodo através do seio coronário. O tempo médio de utilização de radioscopia foi 18,69(±15,2) min. CONCLUSÃO: A utilização da técnica simplificada para cateterização do seio coronário sem utilização de bainha, baseada na anatomia radiológica e no eletrograma intracavitário, enfatizando o componente atrial, no tratamento de portadores de cardiomiopatia dilatada avançada, pela terapia de ressincronização cardíaca, demonstrou resultado satisfatório, índice de complicações pequeno, e baixa exposição do operador a radiação ionizante
Abstract: Biventricular pacing has present good results in treatment of congestive cardiac heart failure in patients with dilated miocardyopathy and interventricular conduction disturbance. PURPOSE: to present a proposal of using a original simplified technique for left epicardial ventricular lead stimulation, based on the radiological imaging of the anatomy and intracavitary electrogram, emphasizing the atrial component, showing the results, complications, highlighting the total fluoro time. METHODS: From October, 2001 up to March, 2007, 234 biventricular pacemaker implantations were performed in previously selected patients, using radiological anatomy and observation of the intracavitary electrogram, focusing on the atrial component, and showing the success rate, complications and total time of radioscopy utilization. RESULTS: The implantation of the system using left ventricular pacing via coronary sinus was not possible in 19(8,1%) patients. Difficulties on the cannulation of the coronary ostium were felt in 30(12,8%) patients and difficulties of lead advancement through the coronary sinus were felt in 52(22%) patients. The mean time of radioscopy utilization was 18.69(±15,2) min. CONCLUSION: the use of a simplified technique for coronary sinus cannulation without the aid of a sheath, based on the radiological imaging of the anatomy and intracavitary electrogram, emphasizing the atrial component, for the treatment of advanced dilated cardiomyopathy patients with cardiac resynchronization therapy, has shown satisfactory results, low incidence of complications, and low exposure of the operator to ionizing radiation
Doutorado
Cirurgia
Doutor em Cirurgia
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Thomson, Caroline L. "Study of phase-matching geometries in bulk and periodically-poled lithium niobate and their use in intracavity terahertz optical parametric oscillators." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3024.
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This thesis describes the experimental implementation of novel intersecting cavity terahertz optical parametric oscillators based on bulk and periodically-poled magnesium oxide-doped lithium niobate. Both collinear and non-collinear phase-matching geometries have been demonstrated and injection-seeding has been implemented in devices using periodically-poled material to reduce threshold and increase the down-conversion efficiency. A comprehensive characterisation of the original intracavity terahertz OPO was undertaken, which revealed the parameters having the greatest impact on OPO efficiency (idler mirror reflectivity and cavity length) and led to a better understanding of the losses in the system. During the characterisation process, generation of further terahertz radiation at the same frequency as that generated by the parametric process was observed and identified as being a result of difference frequency generation (DFG) between the parametrically-generated idler and terahertz waves. This phenomenon had previously only been observed when periodically-poled materials were employed in the system. The effect of this additional DFG process has been analysed in terms of the enhancement of the terahertz field on the basis of the coupled wave equations and physically measured quantities. The use of periodically-poled lithium niobate has been a major part of the research presented in this thesis. A comprehensive study of the modified phase-matching conditions was carried out and both collinear and novel hybrid non-collinear phase-matching geometries were identified. Several computer models were developed to assess the performance of any given grating design in these different geometries and the effects of temperature tuning and pump wavelength variation were also investigated using the models. Experimental studies confirmed the viability of the modelling approach but material limitations (particularly the early onset of crystal damage) limited the outcomes of the experiments. A detailed comparison of the poled and bulk materials was made to highlight the present drawbacks of the poled material. Finally, injection seeding was used to improve the efficiency of the collinear phase-matched PPLN OPOs. When seeding was used the depletion of the pump pulse was increased to the point of being measurable, reaching an upper level of 10%. Coupling constraints placed on the seed laser limited the amount of depletion attained. The potential for injection seeding to be used in the hybrid non-collinear phase-matching scheme was also identified but not realised during the course of this work. Were this technique successful, the tuning range of the intersecting cavity terahertz OPO could be extended to encompass the sub-1THz region, something that has previously been limited by the available idler cavity angles.
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Zhang, Kuanshou. "Intracavity optical nonlinear devices using X(2) quasi-phase-matched material : classical and quantum properties and application to all-optical regeneration." Paris 6, 2002. http://www.theses.fr/2002PA066553.
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Pané, Alemany Regina. "Eficacia de la electroestimulación perineal de superficie versus la electroestimulación intracavitaria en el tratamiento de la incontinencia urinaria secundaria a prostatectomía radical: ensayo clínico aleatorizado." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/671973.
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Introducció: En l'actualitat, la prostatectomia radical és el tractament d'elecció pels homes amb càncer de pròstata localitzat, però, alguns pacients pateixen d'incontinència urinària (IU) després de la cirurgia. Aquesta pèrdua d'orina es converteix en un problema físic, emocional, psicosocial i econòmic. La fisioteràpia del sòl pelvià és un tractament conservador, indolor i econòmic per a aquesta situació en concret, i dins de la mateixa trobem com a tècniques habituals l'entrenament de la musculatura del sòl pelvià i l'electroestimulació muscular perineal. Com a objectiu principal es pretén comparar l'eficàcia del tractament amb electroestimulació perineal de superfície versus el mateix tractament aplicat de manera intra-cavitària, en la reducció de la IU secundària a prostatectomia radical, i la seva repercussió sobre la qualitat de vida.
Material i mètodes: Es va realitzar un assaig clínic controlat i aleatoritzat d'equivalència a simple cec. Es va generar una seqüència d'assignació aleatòria a raó 1: 1 i es va realitzar una inclusió consecutiva fins arribar a un total de 70 pacients. Els grups van rebre 1 sessió setmanal durant 10 setmanes consecutives. El grup intervenció (GI) va realitzar la tècnica amb elèctrodes de superfície i el grup control (GC) amb sonda intraanal. Es van recollir les dades basals, en les setmanes 5 i 10, i als 6 mesos posteriors a la finalització del tractament. Els grams d'orina perduts mesurats amb el Pad Test 24h va ser considerada la variable principal. Altres variables d'estudi van ser la qualitat de vida relacionada amb la salut (QVRS) mesura amb els qüestionaris ICIQ-SF, I-QOL i SF-12, l'estat de la musculatura del sòl pelvià, la continuïtat i adherència a el tractament, els efectes adversos i la satisfacció amb el tractament.
Resultats: Es van incloure un total de 70 homes amb una mitjana d'edat de 62,8 (DE 9,4) anys. Tots havien estat intervinguts quirúrgicament de prostatectomia radical i posteriorment van presentar IU derivada d'aquesta cirurgia.
Els participants van presentar un Pad Test 24h basal mitjà de 328,3 (DE 426,1) grams. El Pad Test mostrar una disminució significativa dels grams d'orina perduts a les 5 setmanes (121,7 gr en el GC i 159,1 al GI) i 10 setmanes (235,8 gr en el GC i 248,5 al GI) de tractament en ambdós grups (GC p <0,001 i GI p <0,001). La diferència va deixar de ser significativa un cop finalitzat el tractament durant els 6 mesos posteriors (17,3 gr en el GC, p = 0,230 i 11,7 gr en el GI, p = 0,438). Els qüestionaris ICIQ-SF, I-QOL i SF-12 també van mostrar una millora significativa en la QVRS en els diferents períodes d'avaluació. En l'anàlisi de les diferències entre els dos tractaments, en relació a la variable principal (Pad Test 24h) i en relació a la resta de variables recollides mitjançant els qüestionaris de QVRS, s'observa l'absència de significació estadística.
Conclusions: Els resultats sobre l'equivalència terapèutica de la EEM aplicada amb elèctrodes de superfície i la EEM aplicada amb sonda intraanal no són concloents i, per tant, no permeten establir l'equivalència terapèutica entre les dues modalitats de tractament. No obstant això, la disminució en els grams d'orina perduts al llarg de la teràpia és clínica i estadísticament significativa en ambdós grups; a més, les diferències en les pèrdues d'orina entre el grup intraanal i el grup de superfície no són significatives, és a dir, la EEM sembla ser eficaç i l'eficàcia de les dues formes d'administració no son diferent des del punt de vista estadístic.
La utilització de la EEM millora significativament la QVRS dels participants des de l'inici al final del tractament en les dues modalitats.Introducción: En la actualidad, la prostatectomía radical es el tratamiento de elección para los hombres con cáncer de próstata localizado,sin embargo, algunos pacientes sufren de incontinencia urinaria (IU) después de la cirugía. Esta pérdida de orina se convierte en un problema físico, emocional, psicosocial y económico. La fisioterapia del suelo pelviano es un tratamiento conservador, indoloro y económico para esta situación en concreto, y dentro de la misma encontramos como técnicas habituales el entrenamiento de la musculatura del suelo pelviano y la electroestimulación muscular perineal. Como objetivo principal se pretende comparar la eficacia del tratamiento con electroestimulación perineal de superficie versus el mismo tratamiento aplicado de manera intra-cavitaria, en la reducción de la IU secundaria a prostatectomía radical, y su repercusión sobre la calidad de vida. Material y métodos: Se realizó un ensayo clínico controlado y aleatorizado de equivalencia a simple ciego. Se generó una secuencia de asignación aleatoria a razón 1:1 y se realizó una inclusión consecutiva hasta alcanzar un total de 70 pacientes. Los grupos recibieron 1 sesión semanal durante 10 semanas consecutivas. El grupo intervención (GI) realizó la técnica con electrodos de superficie y el grupo control (GC) con sonda intraanal. Se recogieron los datos basales, en las semanas 5 y 10, y a los 6 meses posteriores a la finalización del tratamiento. Los gramos de orina perdidos medidos con el Pad Test 24h fue considerada la variable principal. Otras variables de estudio fueron la calidad de vida relacionada con la salud (CVRS) medida con los cuestionarios ICIQ-SF, I-QOL y SF-12, el estado de la musculatura del suelo pelviano, la continuidad y adherencia al tratamiento, los efectos adversos y la satisfacción con la terapia. Resultados: Se incluyeron un total de 70 hombres con una media de edad de 62,8 (DE 9,4) años. Todos habían sido intervenidos quirúrgicamente de prostatectomía radical y posteriormente presentaron IU derivada de esta cirugía. Los participantes presentaron un Pad Test 24h basal medio de 328,3 (DE 426,1) gramos. El Pad Test mostró una disminución significativa de los gramos de orina perdidos a las 5 semanas (121,7 gr en el GC y 159,1 en el GI) y 10 semanas (235,8 gr en el GC y 248,5 en el GI) de tratamiento en ambos grupos (GC p<0,001 y GI p<0,001). La diferencia dejó de ser significativa una vez finalizado el tratamiento durante los 6 meses posteriores (17,3 gr en el GC, p=0,230 y 11,7 gr en el GI, p=0,438). Los cuestionarios ICIQ-SF, I-QOL y SF-12 también mostraron una mejora significativa en la CVRS en los diferentes periodos de evaluación. En el análisis de las diferencias entre los dos tratamientos, en relación a la variable principal (Pad Test 24h) y en relación al resto de variables con valores recogidos mediante los cuestionarios de CVRS, se observa la ausencia de significación estadística. Conclusiones: Los resultados sobre la equivalencia terapéutica de la EEM aplicada con electrodos de superficie y la EEM aplicada con sonda intraanal no son concluyentes y, por tanto, no permiten establecer la equivalencia terapéutica entre ambas modalidades de tratamiento. Sin embargo, la disminución en los gramos de orina perdidos a lo largo de la terapia es clínica y estadísticamente significativa en ambos grupos; además, las diferencias en las pérdidas de orina entre el grupo intraanal y el grupo de superficie no son significativas, es decir, la EEM parece ser eficaz y la eficacia de las dos formas de administración no ser diferente desde el punto de vista estadístico. La utilización de la EEM mejora significativamente la CVRS de los participantes desde el inicio al final del tratamiento con los dos modos de aplicación.
Introduction: Radical prostatectomy is the gold standard treatment for men with localized prostate cancer. This technique is associated with post-operative urinary incontinence. Pelvic floor physiotherapy is a conservative, painless and economical treatment for this specific situation. Kegel exercises and perineal electrostimulation are common techniques to train pelvic floor muscles. The perineal electrostimulation can be applied to the patient with surface electrodes or by an intra-cavitary anal probe. The main objective is to compare the efficacy of the treatment with transcutaneous perineal electrostimulation versus the same intra-cavitary treatment to reduce the magnitude of urinary incontinence after radical prostatectomy, and the impact on the quality of life. Material and method: An equivalence, single-blind, randomized controlled trial was conducted. The groups received 1 weekly therapy session for 10 consecutive weeks. The intervention group (IG) performed the technique with surface electrodes and the control group (CG) with intraanal probe. Data were collected at baseline, at weeks 5 and 10, and 6 months after the end of treatment. Grams of urine lost, measured with the 24h Pad Test, was considered the main variable. Other study variables were health-related quality of life (HRQoL) measured with the ICIQ-SF, I-QOL and SF-12 questionnaires, pelvic floor musculature condition, continuity, adherence to treatment, adverse effects, and satisfaction with treatment. Results: A total of 70 men were included with a mean age of 62.8 (SD 9.4) years. All had undergone radical prostatectomy surgery and subsequently presented UI derived from this surgery. The participants presented a mean baseline 24h Pad Test of 328.3 (SD 426.1) grams. The Pad Test showed a significant decrease in the urine lost grams at 5 weeks (121.7 g in the CG and 159.1 g in the IG; p<0.001) and 10 weeks (235.8 g in the CG and 248.5 g in the IG; p<0.001) of treatment. The difference was no longer significant once the treatment was finished during the subsequent 6 months (17.3 g in the CG, p=0.230 and 11.7 g in the IG, p=0.438). The ICIQ-SF, I-QOL and SF-12 questionnaires also showed a significant improvement in HRQoL in the different evaluation periods. In the CG, an increase of 4.1 points in the ICIQ-SF, an increase of 21.1 points in the I-QOL, a decrease of 1.6 points in the mental and a decrease of 2.7 points in the physical dimensions of SF-12 were observed. In the IG, an increase of 3.8 points in the ICIQ-SF, an increase of 25.1 points in the I-QOL, a decrease of 1.6 points in the mental and a decrease of 2 points in the physical dimensions of SF-12 were also noted. In the analysis of the differences between the two treatments, in relation to the main variable (Pad Test 24h) and to the rest of variables collected through the HRQoL questionnaires, absence of statistical significance was found. Conclusions: The results on the therapeutic equivalence of perineal MES applied with surface electrodes and that applied with an intraanal probe are not conclusive and, therefore, do not allow establishing the therapeutic equivalence between both treatment modalities. However, the decrease in the grams of urine lost throughout the therapy is clinically and statistically significant in both groups (after 5 weeks of treatment and after 10 weeks of treatment); furthermore, the differences in urine losses between the intraanal group and the surface group are not significant, that is, MES seems to be effective and the efficacy of the two forms of administration not to be different from a statistical point of view. The use of electrostimulation improves significantly the HRQoL of the participants from the beginning to the end of the treatment with both modes of application.
Universitat Autònoma de Barcelona. Programa de Doctorat en Metodologia de la Recerca Biomèdica i Salut Pública
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Hiebeler, Miriam [Verfasser], and Oliver [Akademischer Betreuer] Reich. "Kombinierte intravesikale Chemotherapie und intracavitäre Hyperthermie zur Behandlung nicht-muskelinvasiver Blasentumore – Retrospektive Ergebnisanalyse des Patientenkollektivs der Urologie des Klinikum Harlachings (2009-2015) / Miriam Hiebeler ; Betreuer: Oliver Reich." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/1208150510/34.
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Grishina, Vera. "Blue laser for precision spectroscopy : toward optical frequency standard referenced to laser cooled calcium atoms." University of Western Australia. School of Physics, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0046.
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Optical frequency standards with the reference to a narrow electronic transition of a laser-cooled collection of neutral atomic particles are becoming essential tools of research in modern precision physics experiments. In the core of a building block of an optical frequency standard is the optical continuous wave laser that has a good spectral purity of the emitted light. Such a stable optical oscillator is highly desirable in high resolution spectroscopy, if it emits in a good quality beam at a short visible wavelength. This Master thesis explores efficient techniques for building such an optical frequency source intended for use in the cooling and trapping of Calcium atoms scheme. The strong dipole transition at the blue wavelength in the atomic Calcium is needed to reduce the kinetic energy of atoms by nearly six orders of magnitude. A further reduction in the thermal energy of the laser cooled atoms is required to locate with ultra-high precision the 400 Hz narrow clock transition of the stable 40Ca isotope. The experimental methods that achieve this and approach sub-microkelvin temperature of the laser cooled bosonic isotopes of alkaline earths are inspected. The blue laser with a uniform intensity distribution in the beam is useful to maintain the trapped number of cold atoms during these experiments. The spectroscopic properties of the relative transitions in Calcium atom are also reviewed following relevant publications in the area. The constructed blue laser can be used as a primary wavelength source in the lasers network for cooling and trapping of Calcium atoms. These experiments will constitute part of the project to build an optical atom clock referenced to 40Ca narrow linewidth transition. The blue laser is constructed by generating second harmonic in a Potassium Niobate crystal, which is temperature controlled to use a type-I noncritical phase-matching of the optical nonlinear process. The power of the intracavity-generated second harmonic depends on the resonance properties of the optical resonator where this nonlinear crystal is placed. The study is aimed at characterising the designed optical resonator and the experimental parameters that describe it. The formula is derived that relates the resonance power enhancement coefficient with finesse and the power coupling contrast of a passive optical cavity. The obtained relationship is verfied during the experiments. The produced efficiency of the intracavity second harmonic generation is approx. 0.0023 mWblue/(mWred)2. The research work also examines the noise characteristics of the infrared diode laser that is used as a pump source for the intracavity generated second harmonic and determines the spectroscopic precision of the produced blue light. The frequency locking experiment is analysed using the unbalanced scheme of the polarisation stabilisation technique. The designed optical buildup cavity became a part of the unbalanced frequency discriminator in such a scheme. The results demonstrate high gain of frequency noise suppression of the stabilised laser. The unbalanced arrangement of the H}ansch-Couillaud technique has been possible due to a very low amplitude noise of semiconductor lasers.
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Bizet, Laurent. "Spectrométrie laser avec sources moyen infrarouge largement accordables et application à la détection de gaz." Thesis, Reims, 2019. http://www.theses.fr/2019REIMS010/document.
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La détection de gaz est un domaine d’intérêt pour de nombreuses applications telles que la surveillance de la pollution atmosphérique, la détection d’explosifs, l’analyse des émissions respiratoire de patients, etc... La spectrométrie par lasers accordables permet la réalisation d’instruments compacts et bénéficiant de performances élevées (sélectivité, résolvance et résolution temporelle). Par ailleurs, l’utilisation de lasers à cascade quantique (QCL) permet d’accéder au moyen infrarouge (Mid-IR), où les raies d’absorption des molécules d’intérêt sont plus intenses, ce qui améliore la sensibilité des dispositifs. Les travaux de cette thèse ont porté sur le développement de dispositifs basés sur des QCL pour la détection de gaz. La première partie des travaux porte sur l’exploitation de nouvelles sources Mid-IR telles que les barrettes de QCL multiplexées et les barrettes de QCL cohérents. La seconde partie concerne le développement d’un dispositif intracavité sur lequel une technique de détection par mesure de la tension du laser a été validée. Cette technique possède l’avantage de ne pas nécessiter de détecteur optique et de fonctionner quelle que soit la longueur d’onde du laserThe field of gas detection is interesting for many applications such as monitoring of air pollution, explosives detection, breath analysis, etc. Tunable laser spectrometry allows to create compact instruments with high performances (selectivity, spectral and temporal resolution). Mid-Infrared (Mid-IR) region can be accessed with the use of Quantum Cascade Laser (QCL). In this region, absorption lines of the molecules of interest are more intense, which improves the devices sensitivity. The work presented in this thesis is focused on the development of QCL-based gas detection devices. First part presents the use of new Mid-IR sources such as multiplexed QCL array and coherent QCL array. Second part is focused on the development of an intracavity setup and a detection technique based on the QCL voltage measurement. This technique does not need the use of an optical detector and can be performed whatever the laser wavelength
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Charvat, Ales. "Etude, réalisation et caractérisation d'un spectromètre d'absorption intracavité à l'aide d'un laser Ti:Saphir." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10223.
Full textAbstract:
Les mesures precises de faibles absorptions dues a des molecules en phase gazeuse requierent une technique qui soit a la fois de haute sensibilite et quantitative. La technique de l'absorption intracavite laser (iclas) repond bien a ce double besoin. Notre travail a ete consacree a l'etude, la realisation et la caracterisation d'un spectrometre iclas a l'aide d'un laser ti:saphir pompe par un laser a argon. Pour cela nous avons modelise et compare des structures de cavites en z a astigmatisme compense, lineaire et en anneau a l'aide des matrices abcd. Nous avons entrepris ensuite l'etude de la dynamique spectro-temporelle de tels lasers et etudie les limitations de la sensibilite. Ces etudes ont montre que la longueur equivalente d'absorption de notre spectrometre est de l'ordre de 30 000 km ce qui est proche de la sensibilite limite due a l'emission spontanee. D'autre part les etudes theoriques et experimentales du regime transitoire des oscillations de relaxation ont confirme que l'absorption intracavite evolue lineairement en fonction du temps de generation durant cette periode. Du fait d'un temps d'etablissement important, la notion de temps de generation effectif a du etre introduite. Nous avons egalement evalue l'influence sur le fonctionnement du laser des gradients d'indice dans le cristal, gradients qui sont dus soit au pompage longitudinal (lentille thermique), soit a l'effet kerr (blocage des modes). L'etude des etats de polarisation de la lumiere nous a permis de degager une conclusion importante: la birefringence du cristal reduit la sensibilite du spectrometre iclas en provoquant d'importantes modulations spectrales et en empechant le fonctionnement unidirectionnel dans un laser en anneau. Pour s'en affranchir nous avons utilise un cristal dont l'axe optique est parallele au faisceau laser. Notre spectrometre a deja permis d'obtenir de nombreux spectres moleculaires en cellule (chd#3, n#2o, co#2) et en jet supersonique (ch#4, no#2)