Tesis sobre el tema "Thérapie ultrasonore"
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Pernot, Mathieu. "Nouvelles techniques de thérapie ultrasonore et de monitoring". Phd thesis, Université Paris-Diderot - Paris VII, 2004. http://pastel.archives-ouvertes.fr/pastel-00000992.
Texto completoCao, Elodie. "Développement d’une sonde ultrasonore oesophagienne pour la thérapie cardiaque". Electronic Thesis or Diss., Lyon, 2022. http://www.theses.fr/2022LYSE1013.
Texto completoVentricular arrhythmias are a major public health issue. Sudden cardiac death is responsible for 200,000 to 350,000 deaths in Europe, each year. Radiofrequency ablation is the gold standard to treat these pathologies. The procedure consists in ablating or isolating electrically arrhythmogenic regions. However, its efficiency is limited. High intensity focused ultrasound is a promising alternative through its ability to create precise thermal lesions deeply, at distance from the transducer, without damaging intervening tissues. Esophageal approach offers a good acoustic window on the heart. Thus, transesophageal ultrasonic probe could create transmural thermal lesions on ventricular walls. A transesophageal 2.6-MHz plane ultrasound probe, composed of 32 therapy rings and two perpendicular bimodal imaging transducers was developed to guide procedures and to treat targeted regions located at a maximum distance of 10 cm. It was characterized acoustically. Then, in vitro experiments on cardiac tissues and ex vivo experiments on isolated perfused porcine hearts were conducted to confirm the probe ability to create lesions. The aim was achieved in vitro but the technical limits and the complex heart model prevent the probe from creating lesions ex vivo. A numerical model to simulate HIFU thermal ablations in mobile and deformable heart was also developed to predict how motion affects HIFU treatment efficiency. Experiments on thermosensitive gels validated the model ability to determine lesion volume in gel. However, experiments conducted on Langendorff hearts demonstrated that there was a difference between numerical and experimental results. Thus, the model is not accurate enough to compute precise temperature measurements in mobile and perfused heart during HIFU treatment, but it can provide relative results on heating variation
Berti, Romain. "Caractérisation d'agents de contraste ultrasonore pour l'imagerie et la thérapie". Paris 6, 2010. http://www.theses.fr/2010PA066711.
Texto completoAubry, Jean-François. "Focalisation ultrasonore adaptative : application à l'imagerie et à la thérapie du cerveau". Paris 7, 2002. http://www.theses.fr/2002PA077012.
Texto completoGateau, Jérôme. "Imagerie ultrasonore ultrarapide d'évènements de cavitation : application en thérapie par ultrasons et imagerie de détection". Phd thesis, Université Paris-Diderot - Paris VII, 2011. http://pastel.archives-ouvertes.fr/pastel-00863591.
Texto completoGross, Dominique. "Conception et évaluation d'une sonde CMUT mixte dédiée à la thérapie ciblée à guidage ultrasonore". Thesis, Tours, 2015. http://www.theses.fr/2015TOUR3313/document.
Texto completoPresented for the first time in 1994, capacitive micromachined ultrasonic transducers (CMUT) are a promising alternative to the piezoelectric technology for electroacoustic transduction. Particularly, their intrinsic design flexibility and miniaturization capability are strong advantages for the manufacturing of high-end Ultrasound-guided Focused Ultrasound (USgFUS) probes. The work presented in this Ph.D. dissertation is devoted to the f irst development of a USgFUS CMUT probe. After a general introduction of the CMUT technology and the context of this research project, the development is reported starting from the preliminary numerical studies to the most advanced characterizations of the fabricated device. The first results demonstrate the benefits of this technology for the targeted applications
Gâteau, Jérôme. "Imagerie ultrasonore ultrarapide d'événements de cavitation : application en thérapie par ultrasons et imagerie de détection". Paris 7, 2011. http://www.theses.fr/2011PA077013.
Texto completoThe onset of cavitation activity in an aqueous medium is linked to the formation of gas/vapour-filled cavities of micrometric size. This formation can be acoustically mediated and is then called acoustic bubble nucleation. We focus here in the activation of seed nucléi by short (a few cycles) and high amplitude ultrasonic excitation (order of magnitude MPa). Bubbles are generated during the rarefaction phase of the wave and are transient (they dissolve). The nucleation properties of biological tissues are little known. However, they can be assessed using ultrasound: the formation of a bubble results in the appearance of a new scatterer (which can be detected with a pulse-écho detection), and each cavitation event generates an acoustic emission (detected with passive reception). In n this PhD manuscript, we use ultrafast ultrasound imaging (simultaneous acquisition on an array of transducers with a high frame rate) to detect cavitation events. Two in vitro applications were first validated. On one hand, bubble nucleation was performed through a human skull, and transcranial passive detection of a single cavitation event was used in a time reversal process to optimize adaptive focusing for thermal therapy of brain tissue. On the other hand, the formation and dissolution of bubbles in scattering biological tissues (muscle) were detected with a high sensitivity by combining passive detection and ultrafast active imaging. Finally, in vivo experiments on sheep's brain, and others in vitro on animal blood showed that nucleation in biological tissue is a random phenomenon, and high negative pressure are mandatory to initiate nucleation in vivo (< -12MPa)
Daunizeau, Loïc. "Développement de la thérapie ultrasonore conformationnelle par voie interstitielle pour le traitement du carcinome hépatocellulaire". Electronic Thesis or Diss., Lyon, 2020. http://www.theses.fr/2020LYSE1326.
Texto completoHepatocellular carcinoma is the most common primary cancer of the liver. Interstitial thermal ablation procedures constitute a type of curative treatments for this cancer. Given the physical nature of the phenomenon used to modify temperature (radio frequency, micro wave, laser, cryotherapy), those methods may not be able to generate a conformal treatment for a given tumor shape. In some cases, this limitation may induce the thermal ablation of a large volume of non-tumor tissues. The use of an ultrasound interstitial probe mounted with a multi-element transducer capable of generating high intensity focused ultrasound (HIFU) may theoretically help to overcome this limitation. Also a transducer with an important number of elements may also provide in situ imaging. As a first step, the design of a transducer for interstitial ultrasound probe was studied. A specific configuration has been proposed for the treatment of tumors with a diameter of 4 cm. The question of the treatment planning method to adopt to reach an optimal conformal treatment has been then addressed by comparing numerical simulations of different strategies. All strategies were sufficiently conformal and none presented real assets compared to the others. Ultrasound focusing in itself provided the desired conformal thermal ablation. Finally, a robotic platform was developed for driving interstitial dual mode ultrasound probes, both in imaging and in therapy mode. This platform allowed the automatic treatment planning of in vitro tumor mimic phantoms, based on 3D ultrasound reconstruction from the B mode images obtained in situ by the interstitial probe. However, in therapy mode, the probes did not reach their specifications and did not manage to create thermal lesions in in vitro liver tissue sample. The modularity of the robotic platform allowed driving a different HIFU system, which was more robust. With this system, the platform managed to perform with success an automatic treatment planning and then the associated HIFU treatment in in vitro tissue sample
Tanter, Mickael. "Application du retournement temporel à l'hyperthermie ultrasonore du cerveau". Paris 7, 1999. https://pastel.archives-ouvertes.fr/pastel-00650031.
Texto completoProst, Amaury. "Imagerie photoacoustique : application au contrôle de la thérapie ultrasonore et étude de la génération par des nanoparticules d'or". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-01068272.
Texto completoDupenloup, Florence. "Utilisation de signaux codés en thérapie ultrasonore par ultrasons focalisés de haute intensité : application à la focalisation dynamique". Lyon 1, 1996. http://www.theses.fr/1996LYO1T196.
Texto completoSouchon, Rémi. "Application de l'élastographie à l'imagerie du cancer de la prostate et à sa thérapie par ultrasons focalisés". Lyon, INSA, 2004. http://theses.insa-lyon.fr/publication/2004ISAL0018/these.pdf.
Texto completoAn ultrasonic imaging device for prostate elastography was developed. A balloon filled with a coupling liquid served as a compressor. In vitro, the system was capable of imaging the anatomy of the prostate as well as benign and malignant tumors. Then the major influence of the acquisition frame on the image quality in vivo was demonstrated. The system was shown to be able to detect prostate cancer and to visualize the effects of high intensity focused ultrasound (HIFU) therapy in vivo. It was finally shown in vitro that the formation of an elementary HIFU lesion could be observed by passive elastography, using only temperature elevation to create the elastogram
Gerber, Frédéric. "Potentiel des molécules perfluoroalkylées dans la composition de surfactants pulmonaires synthétiques et de microbulles destinées au diagnostic et à la thérapie / Frédéric Gerber". Strasbourg 1, 2006. https://publication-theses.unistra.fr/restreint/theses_doctorat/2006/GERBER_Frederic_2006.pdf.
Texto completoBoulos, Paul. "Ultrasound imaging of the ultrasound thrombolysis". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1251/document.
Texto completoUltrasound 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
Meunier, Anne. "Évaluation in vitro de la thérapie sonodynamique sur cellules cancéreuses : automatisation d'un banc de tests, métrologie et dosimétrie associées". Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL065N.
Texto completoGoudot, Guillaume. "Applications innovantes des ultrasons en pathologie vasculaire : utilisation de l'imagerie ultrarapide dans l'analyse de la rigidité artérielle et des ultrasons pulsés en thérapie Arterial stiffening assessed by ultrafast ultrasound imaging gives new insight into arterial phenotype of vascular Ehlers–Danlos mouse models Aortic wall elastic properties in case of bicuspid aortic valve Segmental aortic stiffness in bicuspid aortic valve patients compared to first-degree relatives Wall shear stress measurement by ultrafast vector flow imaging for atherosclerotic carotid stenosis Pulsed cavitational therapy using high-frequency ultrasound for the treatment of deep vein thrombosis in an in vitro model of human blood clot". Thesis, Sorbonne Paris Cité, 2018. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2215&f=13951.
Texto completoAngla, Célestine. "Fast transcranial acoustic simulations for personalized dosimetry in ultrasound brain therapy". Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPAST207.
Texto completoUltrasound brain therapy is a promising method, as it is non-invasive when ultrasonic waves are sent through the skull. However, the skull bone complex structure strongly attenuates and aberrates the ultrasound beam, altering the dimensions, position and intensity of the focal spot. These focal parameters must be perfectly controlled to ensure both treatment efficacy and safety. Due to the high inter/intra-individual variability of skull geometry and acoustic properties, personalized simulations are required to predict focal characteristics depending on the patient skull and the ultrasonic probe position. Most simulation methods currently in use, such as k-Wave, are very time- and memory-intensive, limiting them to pre-intervention planning tools. The aim of this thesis was to develop a fast and realistic semi-analytical method for ultrasound field computation through the skull. As a first step, we developed a smooth and homogeneous model of the skull, realistic and suited to fast field computation algorithms. To this end, we modeled the skull inner and outer surfaces using a method called "Multi-level Bspline Approximation", and we developed a skull acoustic property homogenization method, which was numerically validated. This smooth and homogeneous skull model was then used as input to the field computation algorithm developed. This algorithm, named SplineBeam, is based on an ultrasonic path computation method that minimizes the time-of-flight function, which is fast and accurate, and which, combined with the pencil method, enables a regular sampling of the ultrasound probe. SplineBeam was validated numerically, by comparison with the pencil method, embedded in the CIVA HealthCare simulation platform, developed at the CEA, and with other numerical solvers (including k-Wave) on a series of configurations, and experimentally, by comparison with hydrophone measured pressure fields through an ex vivo skull sample. SplineBeam simulated fields were found to be closer to the experimentally measured ones than those simulated with k-Wave. This validates both the skull model and the field computation method. Furthermore, SplineBeam can restrict its computation to the focal spot, which allows it to drastically reduce the number of computation points, making it faster than k-Wave by two orders of magnitude, for a large probe
Mondou, Paul. "Contrôle intelligent de la cavitation des microbulles à travers le crâne pour l'optimisation des thérapies ultrasonores". Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPAST188.
Texto completoThe blood-brain barrier (BBB) is the primary interface for exchanges between blood and brain tissue. It remains a major obstacle in the therapeutic management of neurological or cancerous pathologies of the central nervous system (CNS), as over 95% of drugs struggle to reach targeted brain tissues due to the BBB. Approaches optimizing the cerebral delivery of active compounds are crucial to enrich the therapeutic arsenal against CNS pathologies. Since 2001, the use of ultrasound, combined with microbubble injection, has provided a non-invasive method for transient, local, and repeated opening of the BBB without tissue damage. This technique requires rigorous control of in-situ ultrasonic dosimetry: microbubbles need sufficient intensity for effective action (stable cavitation) without oscillating too strongly (inertial cavitation) to avoid the risk of implosion and local adverse effects. Dosimetry is challenging due to the presence of the cranial bone, which is highly heterogeneous and varies among individuals. It has been demonstrated that measuring the oscillation state of microbubbles (cavitation) is possible with the ultrasonic signals backscattered by them. Thus, stable microbubbles reflect only harmonics of the emission frequency, while imploding microbubbles reflect a broaddeband signal characterized by emission at all frequencies. Algorithms have been developed to adjust the ultrasound emission pressure in real-time based on the signals backscattered by microbubbles. This thesis focuses on cavitation control through algorithms using different indices calculated from cavitation signal spectra. The work benefited from ultra-fast electronics, Field Programmable Gate Array, (FPGA) that drastically accelerated the implemented control. An experimental setup was initially constructed to place a stream of microbubbles at the focus of a therapeutic ultrasound transducer. This in vitro device recorded ultrasonic signals backscattered by oscillating microbubbles under various acoustic pressures. The measurements optimized the calculation of indices characterizing different cavitation states. Following these tank measurements, cavitation measurements were conducted during BBB permeabilization experiments in vivo. These results were compared to in vitro results to correlate different cavitation states with biological observations: presence or absence of BBB permeabilization or vascular damage. Based on these results, a cavitation regulation algorithm exploiting the speed provided by the FPGA was constructed. It operates by progressively increasing the acoustic pressure during each ultrasound pulse while maintaining the pressure just below the inertial cavitation threshold. This algorithm was tested in vitro and in vivo. Finally, in a translational approach towards clinical application, cavitation measurements were performed ex vivo using a human half-skull. These measurements demonstrate our ability to capture the necessary indices for the proper functioning of cavitation control algorithms in humans under conditions where the signal is degraded by the substantial thickness of bone to penetrate
Dizeux, Alexandre. "Caractérisation ultrasonore de l'angiogenèse, de l'élasticité et de la microstructure tumorale sous l'effet de thérapies conventionnelles et innovantes". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066113/document.
Texto completoTumor development is complex process made possible thanks to the microenvironment surrounding tumor cell. Modifications induced by tumor cells on their environment enable their own development by remodeling tissues sustaining them and by creating a new vascular network (angiogenesis). The use of several antiangiogenic therapies, inhibiting the sprout of a new vascular network, has been authorized in clinic. These therapies induce strong modifications in tumors at the functional level and following tumor size changes are is not sufficient to fully characterize tumor modifications. The main goal of this thesis was to use different ultrasound-based imaging modalities in order to assess their sensitivity to modifications induced in murine tumor model (colorectal and lung carcinomas) during different type of therapy (chemical: cytotoxic, antiangiogenic / physical: cold plasma, sonosensitization). Modifications of the spatial distribution of microvessels and their functionality were characterized using contrast-enhanced ultrasound (CEUS), alteration of tumor microstructure was assessed using spectral analysis of radiofrequency signal, known as quantitative ultrasound (QUS) and finally variations of mechanical properties in tumor tissues were measured in shear wave elastography (SWE). In order to better understand the origin of the modifications observed in vivo, standard parameters such as level of fibrosis and necrosis were characterize ex vivo in tumor tissue using immunochemistry as gold standard
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.
Texto completoHigh 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
Bing, Fabrice. "Traitement des lésions osseuses par Ultrasons Focalisés de Haute Intensité : de la simulation aux applications cliniques". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD045/document.
Texto completoAfter a “state of art” on bone lesions ablation techniques, bone experimentations presented showed that deep focalisation allows the best lateral periosteal heating. On cement, from which the coefficient α was measured, the same thermic curves were observed. A simulation was done with two values of α (4.7 et 9.9 dB/cm). A higher heating at the periosteal focal point with superficial focalisation and a higher periosteal lateral heating with deep focalisation with a thermic inertia, were confirmed with simulation. Heating was higher with the high α value. A retrospective analysis of the bone lesions treated with minimally invasive treatment showed that 50% of osteoid osteomas and 35.7% of metastases were classified as suitable with MRgHIFU alone. 35.9% additional cases may have been treated with dissection or consolidation. At 1 MHz, US distortion due to the presence of needles in the US cone was observed only with the 13-gauge needle. However, if 18 to 22G needles may induce few distortion, an acoustic barrier may appear if the liquid injected flows in front of the US
Gauthier, Marianne. "Etude de l’influence de l’entrée artérielle tumorale par modélisation numérique et in vitro en imagerie de contraste ultrasonore. : application clinique pour l’évaluation des thérapies ciblées en cancérologie". Thesis, Paris 11, 2011. http://www.theses.fr/2011PA11T088.
Texto completoDynamic contrast-enhanced ultrasonography (DCE-US) is currently used as a functional imaging technique for evaluating anti-angiogenic therapies. A mathematical model has been developed by the UPRES EA 4040, Paris-Sud university and the Gustave Roussy Institute to evaluate semi-quantitative microvascularization parameters directly from time-intensity curves. But DCE-US evaluation of such parameters does not yet take into account physiological variations of the patient or even the way the contrast agent is injected as opposed to other functional modalities (dynamic magnetic resonance imaging or perfusion scintigraphy). The aim of my PhD was to develop a deconvolution process dedicated to the DCE-US imaging, which is currently used as a routine method in other imaging modalities. Such a process would allow access to quantitatively-defined microvascularization parameters since it would provide absolute evaluation of the tumor blood flow, the tumor blood volume and the mean transit time. This PhD has been led according to three main goals. First, we developed a deconvolution method involving the creation of a quantification tool and validation through studies of the microvascularization parameter variability. Evaluation and comparison of intra-operator variabilities demonstrated a decrease in the coefficients of variation from 30% to 13% when microvascularization parameters were extracted using the deconvolution process. Secondly, we evaluated sources of variation that influence microvascularization parameters concerning both the experimental conditions and the physiological conditions of the tumor. Finally, we performed a retrospective study involving 12 patients for whom we evaluated the benefit of the deconvolution process: we compared the evolution of the quantitative and semi-quantitative microvascularization parameters based on tumor responses evaluated by the RECIST criteria obtained through a scan performed after 2 months. Deconvolution is a promising process that may allow an earlier, more robust evaluation of anti-angiogenic treatments than the DCE-US method in current clinical use
Kwiecinski, Wojciech. "Ultrasound cardiac therapy guided by elastography and ultrafast imaging". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066131/document.
Texto completoAtrial fibrillation (AF) affects 2-3% of the European and North-American population, whereas ventricular tachyarrhythmia (VT) is related to an important risk of sudden death. AF and VT originate from dysfunctional electrical activity in cardiac tissues. Minimally-invasive approaches such as Radio-Frequency Catheter Ablation (RFCA) have revolutionized the treatment of these diseases; however the success rate of RFCA is currently limited by the lack of monitoring techniques to precisely control the extent of thermally ablated tissue.The aim of this thesis is to propose novel ultrasound-based approaches for minimally invasive cardiac ablation under guidance of ultrasound imaging. For this, first, we validated the accuracy and clinical viability of Shear-Wave Elastography (SWE) as a real-time quantitative imaging modality for thermal ablation monitoring in vivo. Second we implemented SWE on an intracardiac transducer and validated the feasibility of evaluating thermal ablation in vitro and in vivo on beating hearts of a large animal model. Third, a dual-mode intracardiac transducer was developed to perform both ultrasound therapy and imaging with the same elements, on the same device. SWE-controlled High-Intensity-Focused-Ultrasound thermal lesions were successfully performed in vivo in the atria and the ventricles of a large animal model. At last, SWE was implemented on a transesophageal ultrasound imaging and therapy device and the feasibility of transesophageal approach was demonstrated in vitro and in vivo. These novel approaches may lead to new clinical devices for a safer and controlled treatment of a wide variety of cardiac arrhythmias and diseases