Rozprawy doktorskie na temat „Ultrasons en médecine – Innovation”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Ultrasons en médecine – Innovation”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
Cilleros, Celia. "Développement d’un traitement par ultrasons focalisés de haute intensité par voie peropératoire pour les tumeurs pancréatiques". Electronic Thesis or Diss., Lyon, 2021. http://www.theses.fr/2021LYSE1089.
Pełny tekst źródłaCurrently, management options for locally advanced pancreatic tumors are extremely limited. Surgical resection cannot be considered due to the non-reconstructible vascular involvement of the tumor. High intensity focused ultrasound (HIFU) treatments have demonstrated their potential in the palliative treatment of pancreatic cancers. The thesis project focuses on the definition of HIFU treatment parameters that induce necrosis of the targeted pancreatic parenchyma while preserving the vascular permeability of an artery included in the destroyed area, using an intraoperative therapy probe with a toroidal transducer and an integrated ultrasound imaging probe. For the assessment of arterial flow, real-time Doppler imaging monitoring was developed during the HIFU procedure. Treatment parameters were chosen to allow acquisition of the Doppler signal between HIFU emission phases with a duty cycle of 40% therapy time and 60% imaging time, for a total duration of 900 seconds. A perfused model was used to evaluate the impact of in vitro treatment parameters on the lesion induced. The lesions obtained with the application of the duty cycle were on average 20% smaller than the lesions without duty cycle, but this reduction was considered acceptable regarding to the safety benefit of treatment with Doppler imaging. A first preclinical study demonstrated the occurrence of reversible arterial spasm following repeated HIFU treatments on the targeted artery. Thermal ablations of approximately 20 mm in diameter were generated around the targeted artery without causing definitive vascular occlusion or thrombosis in the short and medium term. Nevertheless, with a perspective of using this HIFU treatment in humans and thus with the objective of ensuring the safety of the treatment, a predictive tool for arterial spasm has been developed. New studies have identified alterations in the arterial signal during HIFU treatment, reflected by the appearance of a turbulent component upstream of the treated area before the arterial spasm occurs. A tool based on signal dissimilarity was developed and patented based on these signal changes. The acceleration of these modifications allowed to anticipate the arterial spasm in real time and thus a feedback on the HIFU treatment. Preclinical studies allowed to define a threshold on this acceleration beyond which the appearance of stenosis seemed systematic if the treatment was carried out. Depending on the parameters applied, tissue necrosis up to 17 mm in diameter was induced in the pancreatic tissue and around the target vessel without induction of arterial spasm and while maintaining vascular patency. Doppler imaging associated with the real-time tool confirmed the persistence of arterial flow during HIFU treatments. These safe and effective preclinical treatments allow us to consider a Phase I-II clinical trial evaluating HIFU destruction of locally advanced tumors of 10 to 15 mm in diameter in humans
Helbert, Alexandre. "L'imagerie moléculaire de contraste ultrasonore en oncologie : Utilisation des microbulles BR55 ciblant le VEGFR2 dans la détection de l’angiogenèse tumorale, le guidage thérapeutique et l'évaluation de l'efficacité de traitements antiangiogéniques et cytotoxiques". Electronic Thesis or Diss., Lyon, 2022. http://www.theses.fr/2022LYSE1076.
Pełny tekst źródłaUltrasound contrast imaging has grown considerably in recent decades. Several intravascular ultrasound contrast agents, encapsulated gas microbubbles, have been marketed for applications such as cardiovascular imaging and radiology. Following the demonstration of their effectiveness, further research was conducted. A new generation of microbubbles has been developed : targeted microbubbles. Their particularity is to contain, on their shell, a ligand that can bind to specific vascular markers of a pathology such as markers of tumor angiogenesis. To date, only one molecular ultrasound contrast agent, the so-called BR55, has been tested in humans for the detection of tumors of the prostate, breast and ovary. The objective of this work was to explore the possibilities of BR55, beyond diagnosis. The experimental work was performed on rodent models. In the first part of this work, it was necessary to master the use of ultrasound molecular contrast imaging in order to guarantee the robustness of the experiments performed and of the results obtained. BR55 has the particularity of being able to bind to a receptor, VEGFR2, overexpressed in the process of tumor angiogenesis. The BR55 microbubbles attached to this receptor allow visualization of the lesion by contrast imaging. The second part of this work was to follow the evolution of VEGFR2 expression during an antiangiogenic treatment targeting this receptor. We were able to demonstrate the precocity with which the monitoring of VEGFR2 expression by BR55 can objectify the tumor response to treatment. Finally, we used BR55 microbubbles to guide a focused ultrasound therapy to target the localization of doxorubicin release from sonosensitive liposomes. Not only was it possible to perform the treatment guidance by ultrasound molecular contrast imaging, but again the use of BR55 allowed to follow the response to the treatment. The results presented in this thesis pave the way for potential new uses of BR55 for therapeutic monitoring and guidance of treatments by ultrasound molecular contrast imaging
Férin, Guillaume. "Optimisation de Réseaux Ultrasonores Haute Densité". Tours, 2006. http://www.theses.fr/2006TOUR3313.
Pełny tekst źródłaDu, Burck Frédéric. "Atténuation acoustique dans un milieu poroélastique fibreux : application à la caractérisation tissulaire ultrasonore du myocarde". Paris 12, 1988. http://www.theses.fr/1988PA120037.
Pełny tekst źródłaMachet, Laurent. "Utilisation des ultrasons pour augmenter l'absorption percutanée : la phonophorèse". Tours, 1997. http://www.theses.fr/1997TOUR3308.
Pełny tekst źródłaGleizal, Arnaud. "Applications des ultrasons en chirurgie maxillofaciale : stimulation de la régénération osseuse-piézochirurgie". Lyon 1, 2009. http://www.theses.fr/2009LYO10026.
Pełny tekst źródłaThe maxillo-facial surgeon deals, in his daily work, with two problematic situations: - to cut bone in the facial bones with important soft tissues injury risk. - to take care of patients with bone deficit that could have originated either in trauma or in a congenital malformation, or be iatrogenic. The purpose of this work was: - to develop new surgical techniques safer by using ultrasonic instruments which have the ability to cut bone without damaging soft tissues - to understand and optimize the mechanisms of bone regeneration of a certain type of ultrasound, the LIPUS (low intensity pulsed ultrasound) on the cranial and facial bones both in vitro and in vivo. Results: - According to preliminary studies in animals, we described in humans new techniques for mandibular sagittal splitting, palatal expansion, and cranial surgery, using a piezoelectric scalpel which allows decreasing morbidity from these surgeries. - We have made progress in the understanding of gene stimulation of osteoblasts by LIPUS showing stimulation of genes involved in transcription cell and also in optimizing treatment protocols in vivo highlighting reconstruction predominant bone to 300mW / cm2
Belamari, Mohamed El Yazid. "Estimation de l'atténuation des ultrasons dans les tissus biologiques de faible épaisseur : application à la caractérisation tissulaire du myocarde in vivo". Paris 12, 1991. http://www.theses.fr/1991PA120024.
Pełny tekst źródłaBaldeweck, Thérèse. "Mesure de l'atténuation ultrasonore dans les milieux biologiques fortement atténuants : application à la caractérisation de la peau". Paris 12, 1995. http://www.theses.fr/1995PA120011.
Pełny tekst źródłaDautraix, Isabelle. "LaStéréo échographie. : Une nouvelle technique de visualisation volumique de données ultrasonores". Lyon, INSA, 1993. http://www.theses.fr/1993ISAL0012.
Pełny tekst źródłaThis work concerns the presentation in relief of medical ultrasonic data obtained by echography B. The originality of this study consists in transposing the classical stereoscopic technicals in the field of ultrasonic imaging. By analogy with the stereo-radiography by X rays, the principle of the stereo-echographis drawn up. An homogeneous volume of data, in Cartesian coordinates, is obtained by interpolation of the ultrasonic cross-sectional images acquired by translation or rotation of an echographic probe. Thanks to the collinear equations of the photogrammetry, two stereo-echograms of the ultrasonic volume are computerized. The value of the parameters of simulated systems of shot is chosen so that the visual restitution of the relief is optimized. Moreover, in order to make the restitution of the relief easier, the ultrasonic data can be pre-treated before the calculation of the stereo-echograms and some synthetic data (simple geometrical volumes) can be added to the data. The algorithms of the computation of the stereo-echograms have been first validated on physical phantoms and then applied on actual ultrasonic data (liver, foetus,. . . ). Contrary to the technicals of surface or volume rendering, which are difficult to apply to ultrasonic data which are very noisy by nature, the stereo-echography provides a presentation in true relief which makes the interpretation and the understanding of 3D complicated structures easier
Mühlen, Sérgio Santos. "Étude et optimisation d'un lithotriteur urinaire percutané : association des ultrasons de puissance et des ondes de choc électro-hydrauliques". Vandoeuvre-les-Nancy, INPL, 1989. http://www.theses.fr/1989NAN10352.
Pełny tekst źródłaDenis, Florence. "Tomographie acoustique d'objets faiblement réfringents". Lyon, INSA, 1990. http://www.theses.fr/1990ISAL0015.
Pełny tekst źródłaRibault, Mathieu. "Caractérisation ultrasonore de lésions induites par ultrasons focalisés de haute intensité". Lyon 1, 1999. http://u556.lyon.inserm.fr/theses/pdf/ribault.pdf.
Pełny tekst źródłaVeillet, Sébastien. "Enrichissement nutritionnel de l'huile d'olive : entre tradition et innovation". Phd thesis, Université d'Avignon, 2010. http://tel.archives-ouvertes.fr/tel-00518042.
Pełny tekst źródłaHans, Didier. "Validation des mesures ultrasoniques sur le calcanéum : application à la physiopathologie des ostéoporoses". Lyon 1, 1993. http://www.theses.fr/1993LYO1T299.
Pełny tekst źródłaLucidarme, Olivier. "Quantification non invasive de la microcirculation par imagerie ultrasonore fonctionnelle de contraste avec les techniques de destruction reperfusion". Paris 12, 2003. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990002118320204611&vid=upec.
Pełny tekst źródłaOur aim was to study the potential for quantitative contrast enhanced functional ultrasound imaging (fUSI) to assess microcirculation. We described in vitro and in vivo the "entrance in the section phenomenon" that introduces a distortion of the refilling curves when the vessels that feed the region or interest have previouslv traveled across the ultrasound tield. We validated in vitro a b model based on the destruction phase of microhuhbles during ultrasound emission. This model allows the estimation of quantitative flow data during acquisitions of only 1 or 2 seconds. We finally studied a non tumor angiogenesis model in 36 mice. Ultrasound measurement (during the destruction phase) ot' the Uractional blood volume in a gel impregnated with growth exhihited a higher correlation vith the fractional vascularized area of gel than with the microvascular density. Microbubble velocity assessed on fUSI did not change as mi crocirculation increased
Saliba, Youakim. "Identification des partenaires de STIM1 dans le cœur normal et hypertrophié". Paris 6, 2012. http://www.theses.fr/2012PA066541.
Pełny tekst źródłaWe previously showed an important role of STIM1 in cardiac hypertrophy; however, the identity of the channels responsible for the STIM1 dependent pro-hypertrophic Ca2+ entry in the rat ventricular myocytes remains to be elucidated. In this study we developed a new method of myocardial non viral gene delivery, by using the combination of ultrasound energy (USE), liposomes and high pressure injections to the rat heart. Due to its simplicity, low toxicity and low immunogenicity, this method produced sufficient number of transfected cells to perform biochemical experiments and single cell physiological measurements. We then characterized the expression profile of TRPCs and ORAIs proteins in both normal and hypertrophied ventricular myocytes, and found an upregulation of TRPC1 in hypertrophied cells. We further used the new gene delivery method to identify and screen for the STIM1 associated channel candidates via RNA interference. We identified TRPC5 as a non-selective Ca2+ channel that operates constitutively in basal conditions with increased activity in cardiac hypertrophy, as well as ORAI3 that functions in both modes: SOCE and constitutive basal Ca2+ entry in concordance with TRPC5. We developed an efficient non-viral cardiac gene delivery which we used to elucidate TRPC5 and ORAI3 as new voltage independent STIM1 regulated Ca2+ channels in the ventricular rat myocytes
Saïd, Ghada. "Elastographie ultrasonore tridimensionnelle : de l'estimation des déformations au module d'Young des tissus biologiques". Lyon, INSA, 2006. http://theses.insa-lyon.fr/publication/2006ISAL0070/these.pdf.
Pełny tekst źródłaMost of studies concerning elastography are focused on the estimation of the axial component of the strain. However when subjected to any load, soft biological media deform in three dimensions. More, in clinical routine, a quantitative reconstruction of soft tissue elasticity (Young’s modulus) might be useful for lateral detection and classification of certain types of tumour. The aim of this work is to estimate a deformation in three dimensions and to build a Young’s modulus mapping. The estimation of the axial deformation is based on the estimation of the local scaling factor. A method based on the interpolation and correlation of RF signals, for lateral displacement estimation has been implemented. Feasibility to reconstruct tissue elastic modulus distribution using axial, lateral and azimutal displacement field has been shown. The methods have been validated with computer simulations and experimentally with a cryogel phantom
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.
Pełny tekst źródłaGreillier, Paul. "Évaluation d’une sonde HIFU transoesophagienne sur coeur battant". Electronic Thesis or Diss., Lyon, 2017. http://www.theses.fr/2017LYSE1342.
Pełny tekst źródłaTransesophageal HIFU was proposed as an alternative to the current atrial fibrillation treatments. The present work described a feasibility study of transesophageal thermal ablation in the heart on beating hearts in vivo non-human primates and ex vivo on isolated heart
Kabongo, Luis. "Simulation et optimisation de trajectoires pour les ultrasons focalisés en thermothérapie". Bordeaux 1, 2007. http://www.theses.fr/2007BOR13526.
Pełny tekst źródłaAbdel, Wahab Abdel Wahab Abdel Hakim. "Caractérisation ultrasonore multiparamétrique du foie humain : corrélation microscopique". Paris 12, 2004. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990002146200204611&vid=upec.
Pełny tekst źródłaTo date, liver imaging remains qualitative and biopsy is the only recourse for liver tissue characterization. The aim of this work is to develop techniques for liver characterization by speed of sound, attenuation and backscattering coefficient measurement. Techniques necessary for the measurement of these ultrasonic parameters in vitro at 20 MHz were first developed. The speed of sound, attenuation and backscatter coefficients were then measured in vitro in the livers of 39 subjects. The measurements' variability and their reproducibility were evaluated. Ultrasonic parameters were found to be sensitive to experimental factors such as temperature, degassing and freezing applied to liver. Finally, the ultrasonic quantitative parameters were compared to the histopathological diagnosis assessed by histology. Our results demonstrate that US parameters are capable to differentiate normal end pathological liver tissue (fibrosis, carcinoma) as well as the sub-groups of liver fibrosis. Our study seems to be the first tissue characterization of the human liver using a multiparametric approach. Such technique is thus promising for pathology diagnosis, the screening for hepatoma in patients suffering from cirrhosis and the evaluation of liver response to therapeutics
POULIN, DIANE. "L'introduction et la diffusion d'une innovation technologique medicale en milieu hospitalier en france : le processus decisionnel". Palaiseau, Ecole polytechnique, 1988. http://www.theses.fr/1989EPXX0011.
Pełny tekst źródłaThrough a case study on the introduction and the diffusion, in france, of the lithotripter (a device apt to break urinary calculi withouth surgical intervention), we try to develop possible answers to a fundamental question facing the public administrator : how to manage innovation? in other words, thanks to a better knowledge of the causes and nature of uncertainties inherent in the decisional process at work in the case of innovations in medical technology, is it possible to conceive a rational and realistic approach that would lead, in situations similar to the one studied here, to a better management of that type of uncertainty? could, then, the public decision-makers achieve a greater efficiency in the realization of their objectives?
Buyck, Dominique. "Influence de la graisse sur les mesures de vélocité et d'atténuation des ultrasons par le calcaneum". Montpellier 1, 1993. http://www.theses.fr/1993MON11041.
Pełny tekst źródłaRouviere, Olivier. "Apport de l'imagerie au traitement du cancer de prostate par ultrasons focalises de haute intensité". Lyon 1, 2003. http://www.theses.fr/2003LYO10121.
Pełny tekst źródłaPham, Thiên-Ly. "Evaluation ultrasonore de l'os cortical par transmission axiale : une approche multiparamétrique". Paris 6, 2010. http://www.theses.fr/2010PA066505.
Pełny tekst źródłaProvent, Pierre. "Segmentation d'images par analyse statistique de textures : application aux images échocardiographiques". Paris 12, 1991. http://www.theses.fr/1991PA120049.
Pełny tekst źródłaVillemain, Olivier. "Nouvelles applications des ultrasons en cardiologie : quantifier la rigidité des structures cardiaques et la modifier". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB056/document.
Pełny tekst źródłaNo abstract
Cambronero, Sophie. "Développement d’un traitement non invasif des tumeurs hépatiques par ultrasons focalisés". Electronic Thesis or Diss., Lyon 1, 2022. http://www.theses.fr/2022LYO10234.
Pełny tekst źródłaHigh-intensity focused ultrasound (HIFU) is a non-invasive treatment modality for solid tumors that provides a localized destruction of deep tissues. The work in this manuscript describes the development of treatment strategies and the design of a toroidal HIFU transducer dedicated to the non-invasive treatment of liver tumors. First, an existing toroidal HIFU device designed for an intraoperative treatment of liver tumors was used to expand the prospects for intraoperative treatment of tumors localized at the hepato-caval confluence. This treatment approach was evaluated in a preclinical study and showed the feasibility of the procedure and the tolerance of the treatment. This same device was then used to evaluate the feasibility of a completely non-invasive HIFU treatment with a toroidal transducer. The feasibility and safety of this non-invasive treatment was demonstrated in a preclinical study in the porcine model. This work highlighted the need for personalized non-invasive HIFU treatments to spare healthy intermediate tissues. Based on these experiences, a new targeting system was developed to ensure an accurate targeting of non-invasive HIFU treatments performed near risky structures. The performance of the new system has been demonstrated on two in vivo protocols for the treatment of the TTTS (Twin to Twin Transfusion Syndrome) and bladder trigone tumors. A new HIFU treatment device was then designed and developed for the non-invasive treatment of liver tumors. The specific cut of this truncated toroidal transducer allows an enlargement of the treated volume without mechanical displacement of the transducer. The therapeutic performance of this device has been evaluated on in vitro and in vivo experiments in the porcine model. This work represents the first step of a non-invasive treatment of hepatic tumors with a toroidal HIFU transducer
Girault, Jean-Marc. "Apport des techniques du traitement du signal à l'analyse et détection de signaux emboliques". Tours, 1999. http://www.theses.fr/1999TOUR4024.
Pełny tekst źródłaSalomir, Rares. "Local hyperthermia by MRI-guided focused ultrasound : fast MR-thermometry and on-line temperature control : feasibility studies of tumor thermal ablation". Bordeaux 1, 2001. http://www.theses.fr/2001BOR12418.
Pełny tekst źródłaGiraud, Jean Yves. "Etude et mise en oeuvre d'un ostéotome assisté par ultrasons". Toulouse 3, 1991. http://www.theses.fr/1991TOU30264.
Pełny tekst źródłaFrançois, Quentin. "Microrobot guidance through neuronavigation for microrobotic neurosurgery". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS314.
Pełny tekst źródłaWhile neurosurgical tools, whose diameter are above 1.2 mm, allow neurosurgeons to move only in a straight line, the microrobotic field has seen huge advances [...]
Greillier, Paul. "Évaluation d’une sonde HIFU transoesophagienne sur coeur battant". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1342/document.
Pełny tekst źródłaTransesophageal HIFU was proposed as an alternative to the current atrial fibrillation treatments. The present work described a feasibility study of transesophageal thermal ablation in the heart on beating hearts in vivo non-human primates and ex vivo on isolated heart
Chenot, Jérémy. "Guidage par l'imagerie ultrasonore des traitements par ultrasons focalisés de haute intensité". Electronic Thesis or Diss., Lyon 1, 2011. http://www.theses.fr/2011LYO10162.
Pełny tekst źródłaThis study takes place under the guidance of high intensity focused ultrasound therapies (HIFU). The use of ultrasound for guidance allows real time monitoring, but low contrast. To compensate this lack of vision, two studies were set up. The first set up was used to evaluated usefulness of hand-held elastography in real time (23 to 60 frames per second) performed and validated by two in vivo protocols. One was performed to visualize VX2 tumors in the rabbit liver so extracorporeal and intraoperative using a diagnostic linear probe (12MHz). The other was carried out on pigs with the same probe but also with a sectorial imaging probe (7.5 MHz) placed in the center of the HIFU transducer. A comparison was conducted with MRI images of the same lesions performed after removal of the treated organ. In both cases, elastograms provide better visualization of the lesion size (R = 0.70) and higher contrast (23dB) compared to ultrasound (R = 0.65, contrast = 3dB). The last part of this work demonstrated that the ultrasound backscattered signal of the liver tissue changed with the temperature. In experiments on in vitro and in vivo pig livers, this changed of signal is linear and correlated (R = 0.85) with a rise in temperature measured by a thermocouple positioned in the focal zone of the transducer. The relation between backscattered signal and temperature is positive in vitro and negative in vivo. This relationship is linear and used to calculate temperature images with a range of 20 to 100 ° C and an accuracy of 5 ° C
Sarafian, Annie. "La lithotripsie : appareils et méthodes actuels". Paris 5, 1988. http://www.theses.fr/1988PA05P176.
Pełny tekst źródłaDurosier, Claire. "Élaboration et comparaison de modèles de prédiction de la fracture ostéoporotique de la hanche, chez la femme agée, à partir des ultrasons et des facteurs de risques cliniques". Lyon 1, 2008. http://www.theses.fr/2008LYO10011.
Pełny tekst źródłaGrondin, Julien. "Evaluation ultrasonore de l'os cortical en transmission transverse : études numérique et expérimentale de la propagation d’ondes circonférentielles pour la caractérisation de la résistance mécanique du col fémoral". Paris 6, 2010. http://www.theses.fr/2010PA066434.
Pełny tekst źródłaLaurent, Christophe. "Développement des traitements HIFU guidés par IRM de température en temps réel : étude sur le foie et le rein". Bordeaux 2, 2008. http://www.theses.fr/2008BOR21583.
Pełny tekst źródłaThe aim of this work was to propose an improvement of HIFU efficacy and safety in highly perfused and mobile organs, using rapid and volumetric MRI thermometry. A first study proposed a quantitative estimation of thermal parameters in pig kidney ex vivo, treated by HIFU, under different arterial flow condition. The excellent correspondence between rapid thermo-MRI and the BHT showed that this model is applicable for describing the spatio-temporal evolution of temperature in highly perfused organ. Secondarily, the possibility to perform rapid and volumetric temperature monitoring, in real time, of HIFU ablations in the kidney and liver was tested. This monitoring was feasible with an excellent spatio-temporal resolution and calculation of thermal dose confirmed that the letal value could be reached in highly perfused and mobile organs. Moreover, it was possible to create necrotic area in kidney and liver without skin bun. Finally, continue volumetric sonication, using thermal diffusivity, allowed an increasing of ablated tissue volume in a limited time. Recent improvements in rapid imaging techniques and optimization of the motion correction might significantly improve the performances of HIFU ablation and allow its use soon in clinical practice
Boulos, Paul. "Ultrasound imaging of the ultrasound thrombolysis". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1251/document.
Pełny tekst źródłaUltrasound therapy techniques emerged very recently with the discovery of high intensity focused ultrasound (HIFU) technology. Extracorporeal ultrasound thrombolysis is one of these promising innovative low-invasive treatment based on the mechanical destruction of thrombus caused by acoustic cavitation mechanisms. Yet, it is a poorly controlled phenomenon and therefore raises problems of reproducibility that could damage vessel walls. Thus, better control of cavitation activity during the ultrasonic treatment and especially its localization during the therapy is an essential approach to consider the development of a therapeutic device. A prototype has already been designed and improved with a real-time feedback loop in order to control the cavitation power activity. However, to monitor the treatment in real-time, an ultrasound imaging system needs to be incorporated into the therapeutic device. It should be able to first spot the blood clot, to position the focal point of the therapy transducer, control the proper destruction of the thrombus, and evaluate in real-time the cavitation activity. Present work focusses mainly on the development of passive ultrasound techniques used to reconstruct cavitation activity maps. Different beamforming algorithms were investigated and validated through point source simulations, in vitro experiments on a wire, and cavitation experiments in a water tank. It was demonstrated that an accurate beamforming algorithm for focal cavitation point localization is the passive acoustic mapping weighted with the phase coherence factor (PAM-PCF). Additionally, in vivo testing on an animal model of acute limb ischemia was assessed. Finally, some optimizations of the previous developed imaging system were carried out as 3D imaging, real-time implementation, and hybrid imaging combining active anatomical imaging with passive cavitation mapping
Abou, Younes Fayez. "Détection des changements des propriétés mécaniques des tissus au contact d'un biomatériau : développement d'une nouvelle méthode basée sur les ultrasons". Compiègne, 2001. http://www.theses.fr/2001COMP1367.
Pełny tekst źródłaVeillet, Sébastien. "Enrichissement nutritionnel de l’huile d’olive : entre tradition et innovation". Thesis, Avignon, 2010. http://www.theses.fr/2010AVIG0237/document.
Pełny tekst źródłaOlive oil is an ancestral product widely known for its benefic effects on human health. Its processing has changed a lot through centuries, especially these past few years with the increasing automation of the production lines. The first part of this manuscript describes these evolutions while the second part gives details on the influence of each processing step on the nutritional composition of the olive oil. We have studied the influence of the crushing systems, liquid-liquid and solid-liquid separations. The optimization of each of these steps allows the endogenous enrichment of the oil with nutrients extracted from the olive fruit. Then, we have also developed exogenous olive oil enrichment methods by bioactive compounds issued from plants and vegetables. In order to restrain the number of extraction steps and avoid the use of petroleum solvents, the olive oil is used as the extraction solvent so the enrichment is directly performed in the oil. To accelerate extraction kinetics that could be very long we developed ultrasound accelerated extraction techniques. The results obtained in this work are very promising and extensions of olive oil available product ranges are possible
Jafari, Sara. "Détection ultrasonore haute fréquence des microbulles et des nanoparticules expérimentales à cœur liquide". Paris 6, 2012. http://www.theses.fr/2012PA066089.
Pełny tekst źródłaThe objective of this work is high frequency (20-40MHz) characterization of the linear and non linear acoustic response of microbubble and experimental liquid-core nanoparticle contrast agents. Linear and non linear ultrasonic sequences were implemented and validated using a single-channel, broad bandwidth high frequency ultrasound prototype. The variation of the high frequency response of Sonovue contrast microbubbles and experimental nanoparticles was evaluated as a function of pressure, tone burst duration and solution concentration. Experimental nanoparticles consisted of perfluorooctyl bromide (PFOB) liquid cores with poly(lactide-coglycolide) (PLGA) shells. The acoustic response was compared for three different shell-thicknesses to radius ratios (0. 25, 0. 35 and 1). Results demonstrate increased second harmonic to fundamental ratio for the 20-MHz pulse inversion, PI, tone burst sequences as compared to the conventional sequence. The experimental liquid-core nanoparticles studied under flow in vitro present detectable linear and nonlinear response at 20 MHz. In vivo measurements are made to investigate the feasibility of high frequency acoustic detection of the liquid-core nanoparticles in an ectopic murine model after intraveneous injection of these nanoparticles. Bolus arrival of liquid core nanoparticles is detected at 20 MHz whereas, under matched conditions, detection was not achieved using a 7-14 MHz clinical ultrasound system. This work demonstrated high frequency detection and nonlinear response from experimental nanoparticles designed for therapy and contrast imaging and investigated the effect of shell type and thickness on this acoustic response
Fournier, Céline. "Caractérisation ultrasonore de la peau in vivo par mesure des coefficients d'atténuation et de rétrodiffusion". Paris 12, 2002. http://www.theses.fr/2002PA120007.
Pełny tekst źródłaTo date, skin imaging with high frequency (20 MHz) ultrasonic systems remains qualitative and biopsy is the only recourse for skin tissue characterization. The aim of this work is to develop techniques for in vivo skin characterization by attenuation and backscattering coefficient measurement. Techniques necessary for the measurement of these ultrasonic parameters in vivo at 20 MHz were first developed: acquisition system calibration, beam diffraction compensation, acquisition gain choice, selection of the region of interest, signal-processing parameters. The attenuation and backscatter coefficients were then measured in vivo in the dernis of 29 subjects. The measurements' variability in a plane parallel te the skin-surface and their reproducibility were evaluated. Ultrasonic parameters were found to be sensitive to experimental factors such as room and skin-surface temperatures and pressure applied to skin during acquisition, to subject-dependent factors such as age and gender, as well as to measurement site. Moreover, attenuation measurements are demonstrated te be sensitive both to dermis attenuation and variation ofbackscattering properties with depth. Finally, an in vitro study was conducted te compare the ultrasonic parameter variations with those of the dermis structure assessed by histology. A protocol was developed to measure the morphometrical parameters of collagen which is the main dermis constituent. The frequency dependence of backscatter was significantly related to the collagen bundle thickness and the integrated backscatter coefficient was related to the fractional area occupied by collagen. Such techniques are thus promising for pathology diagnosis and the evaluation of dermal response to therapeutics and cosmetics
Teyssier, Georges. "Étude du système cardiovasculaire par les ultrasons chez l'ovin foetus et nouveau-né : validation des données morphologiques et doppler : application à l'étude de la circulation transitionnelle et à un modèle d'hypoxie ftale". Saint-Etienne, 1990. http://www.theses.fr/1990STET4015.
Pełny tekst źródłaChenot, Jérémy. "Guidage par l'imagerie ultrasonore des traitements par ultrasons focalisés de haute intensité". Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00661021.
Pełny tekst źródłaZanetti, François. "L’Électricité médicale dans la France des Lumières : histoire culturelle d’un nouveau remède". Thesis, Paris 10, 2011. http://www.theses.fr/2011PA100152.
Pełny tekst źródłaFrom the 1750s, Electricity was the object of widespread scientific and popular curiosity across Europe. Its first use was therapeutic and electric sparks have immediately been applied to paralytics. In France, medically-trained physicians did not become interested on the new treatment until the 1770s. The role of the newborn Société royale de médecine and of Pierre Mauduyt de la Varenne was pre-eminent in fashioning electricity as a properly medical tool, thus excluding natural philosophers and amateurs from its legitimate practice. Not only does this process have institutional and professional dimensions but it also deals with cultural representations in the scientific and medical fields of knowledge and with the behaviour and practices of both the patients and practitioners. We underline the authority of the patients in ther organisation of their own treatment and their being active in the medicalisation process. During the 1780s, there is a sharp social shift in the use of medical electricity, which is thereafter targeted towards the urban poor, in order to regenerate the Nation and put them back to work. Focusing on a single therapeutical means allows us to cross traditional boundaries between the history of medical ideas, social history of the patients and practitioners and cultural history of representations thus integrating the history of medicine to the wider field of Enlightenment history
Libgot, Rachel. "Caractérisation ultrasonore des transformations mécaniques du sang au cours de la coagulation". Tours, 2007. http://www.theses.fr/2007TOUR3313.
Pełny tekst źródłaThe last past decades have been marked by major improvements in high resolution ultrasound imaging. Great advances in transducer technologies allowed to develop ultrasonic probes over 20 MHz and multiple applications on ultrasonic tissue characterization. Whole blood coagulation involves not only biochemical but also mechanical complex transformations. Despite the potentially numerous applications, ultrasonic techniques are not commonly applied to study whole blood clotting process. Actually, the need in terms of standard global test of coagulation, using whole blood sample, is increasing. The study of acoustical parameters during whole blood coagulation in-vitro could provide relevant information about the mechanics of this process. Then this work attempted to respond to the question : Is it possible to describe mechanical changes of a biological medium as complex as blood? The original approach consists in monitoring acoustical parameters assessed simultaneously in backscattering and in double-transmission modes during blood coagulation. The results obtained clearly showed that simultaneous measurement of parameters in double-transmission and backscattering modes are able to identify several stages during the in-vitro blood clotting process. During the very first minutes, red blood cell and plateled aggregations can be described from the backscattering parameters, and liquid-gel transition phase of blood from the double-transmission parameters. In particular, the attenuation coefficient could describe fibrin polymerization which is an important element of the process
Chanel, Laure-Anaïs. "Assistance à la thérapie par ultrasons focalisés de haute intensité (HIFU) : compensation des mouvements physiologiques par asservissement sur images ultrasonores". Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAD003/document.
Pełny tekst źródłaHigh Intensity Focused Ultrasound (HIFU) therapy is a non-invasive and non-ionizing method for ablation of solid tumors. However, intra-abdominal organ motion, mainly due to breathing, is a major hurdle for proper targeting of the tumor. In this context, an all-in-one HIFU robotized system with motion compensation in real-time during HIFU treatment was developed. To this aim, an ultrasound visual servoing working at a frequency of 20 Hz, relying on a fast ultrasonic speckle tracking method for motion estimation, was designed. It uses an interleaved imaging/HIFU sonication sequence, with duty cycle of 80 %, in order to avoid wave interferences. The robotized HIFU system was tested on a tissue mimicking phantom undergoing a 1D and a 2D sinusoidal motion. As a result, motion reduction of more than 80 % in 1D for a frequency of 0.25 Hz and more than 90 % in 2D for a frequency of 0.1 Hz was obtained. However, it couldn't be observed a significant effect of motion compensation on the lesions induced by HIFU
Esnault, Olivier. "Thérapeutique par ultrasons focalisés de haute intensité (HIFU) appliquée à la thyroïde : de l’expérimentation animale à l’essai humain". Electronic Thesis or Diss., Lyon 1, 2009. http://www.theses.fr/2009LYO10340.
Pełny tekst źródła-
Lourenco, de Oliveira Philippe. "Conception de solutions technologiques et d’outils pour le traitement d’organes par ultrasons focalisés guidés par IRM". Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13963/document.
Pełny tekst źródłaTreatment with Focused Ultrasound (HIFU) combined with Magnetic Resonance Imaging (MRI) control is a promising method for xxx thermotherapy on patient free breathing. A technological solution for improving the transfer of electrical power to the ultrasonic transducer around a adjustable impedance matching system has been achieved. A chapter was devoted to the characterization of transducers acoustic field by measure and simulation. The last two chapters concern the development of software tools around the MRI. A method to determinate the thermal parameters of tissues heated, useful to compute an optimal temperature control was developed. Finally, a feasibility study has been conducted on the combination of fast ultrasound motion estimation with robust MRI motion estimation, this to improve the quality of the motion tracking