No description available.

Ahlberg Cameras is a company that manufactures advanced camera systems and inspection equipment for the nuclear industry. Every nuclear plant shuts down their reactors approximately every 18 months to perform visual inspections of the vessels to find cracks and other damage. The company has received a request from Electric Power Research Institute (EPRI) to develop a distance meter that will operate in the reactor vessel, placed in an inspection camera. The device should measure the distance between the camera and an object, and the angle between them. The measurement is performed in air and underwater and the device has therefore a requirement to be waterproof and radiation tolerant.   This thesis work has studied different possible technologies and technically excluded the ones that are not suitable for the intended application. A large part of the study has been about whether sound or light is a good enough source to use in the different technologies. The study has excluded to use sound mainly because the reflection back to the receiver at large angles becomes too weak. The choice of technology stands between structured light and a self-designed trigonometry technology, both using lasers. Tests have been made to determine if laser light underwater can be observed by the camera and the results indicates that lasers work well enough for this kind of application. Further in-depth studies into the sources of errors and measurement accuracy are needed for determining which of the two technologies is the most suitable.

Ce travail avait pour ambition de réaliser un tour d'horizon des nouvelles applications des produits de contraste échographiques en oncologie. Dans un premier temps, après quelques rappels sur les différents anti-angiogéniques disponibles en pratique clinique, nous avons défini la notion de biomarqueur et replacé les différentes modalités d'imagerie parmi les différents biomarqueurs disponibles. Ensuite, après avoir rappelé brièvement les principes de détection du contraste en échographie, nous avons rapporté plusieurs travaux utilisant l'imagerie fonctionnelle chez la souris et chez l'homme. Ces travaux ont permis de souligner les performances de cette technique, notamment lorsqu'on utilise un protocole de destruction-reperfusion pour estimer les paramètres de perfusion tumoraux. En effet, nous avons réussi à mettre en évidence, dans un travail pré-clinique chez la souris, un effet de rebond de la vascularisation tumorale après l'arrêt d'un anti-angiogénique (l'Avastin®) que les paramètres d'imagerie morphologique habituels, basés sur les dimensions tumorales, étaient incapables de dépister durant l'étude. Par ailleurs, nous avons proposé un paramètre estimant la vitalité tumorale, mixte, fondé sur des données morphologiques et fonctionnelles. Dans une seconde étude, et pour la première fois dans la littérature, ce mode d'imagerie fonctionnelle a été choisi pour évaluer la vascularisation tumorale chez l'homme. Nous avons démontré une corrélation et une concordance des paramètres de perfusion relatifs avec ceux obtenus en scanner de perfusion. Ces données sont d'autant plus intéressantes que ces deux modes d'imagerie utilisent des produits de contraste aux propriétés physico-chimiques très différentes. On notera que le MTT estimé en scanner est supérieur à celui estimé en US, probablement en raison des phénomènes de diffusion extra-vasculaire du produit de contraste scannographique. Dans un troisième travail, nous avons utilisé le Sonovue® pour étudier l'effet au cours du temps d'une embolisation intra-artérielle aux micro-particules chargées d'Adriamycine (DC-beads®), comparativement à des micro-particules non chargées (bead block®). Cette étude a démontré les faiblesses d'une exploration radiologique reposant sur les seuls critères de taille, que ce soit le grand axe des tumeurs (critères RECIST) ou même l'estimation du grand axe de tumeur viable (critères EASL, habituellement utilisés en cas de CHC). Cette étude a également démontré les performances d'un paramètre d'évaluation tumorale mixte, fondé sur des données morphologiques et fonctionnelles, qui permet de différencier de façon significative les deux groupes de traitement. Concernant l'imagerie moléculaire, nous avons suivi un protocole permettant de séparer plusieurs étapes préliminaires qui ont été validées : Nous avons expérimenté sur deux souris en échographie de contraste, au cours de cinq injections de contraste successives, la reproductibilité d'injections rétro-orbitaires. Cette reproductibilité apparaissait suffisante pour envisager d'administrer les microbulles ciblées par cette voie, avec un cœfficient de variabilité inférieur à 20% par quantification du pic de rehaussement sur les injections successives en regard des tumeurs des deux souris. Nous avons montré que l'imagerie moléculaire n'est pas adaptée à l'étude de tous les modèles tumoraux et elle est réservée à l'étude de lésions tumorales située en dehors d'organes accumulant les microbulles même en l'absence de ciblage comme la rate, le foie ou même le rein. En dehors de ces réserves, l'imagerie moléculaire semble pouvoir trouver sa place pour la détection et la caractérisation des lésions tumorales d'organes superficiels comme la thyroïde, le sein, ou accessibles par voie endo luminale comme la prostate ou le pancréas / This work aimed to achieve an overview of new applications of ultrasound contrast agents in oncology. Initially, after a few reminders on various anti-angiogenic therapies available in clinical practice, we defined the concept of biomarker and placed the various imaging modalities among the different biomarkers available. Then, after recalling briefly the principles of contrast detection in ultrasound, we have reported several studies using functional imaging in mice and humans. This work has highlighted the performance of this technique, especially when using a protocol of destruction-reperfusion to estimate tumor perfusion parameters. Indeed, we were able to demonstrate, in a pre-clinical work in mice, a rebound effect of tumor vasculature after stop of anti-angiogenic (Avastin ®), that parameters of conventional morphological imaging based on tumor size, were unable to detect during the study. Furthermore, we proposed a parameter able to estimate the tumor vitality, based on morphological and functional data. In a second study, and for the first time in litterature, functional imaging mode by contrast enhanced ultrasound, using destruction-replenishment sequence, was chosen to evaluate the tumor vasculature in humans. We have demonstrated a high correlation and a good concordance of perfusion parameters with those obtained on perfusion CT. These data are particularly interesting because these two modes of imaging contrast agents have very differents physico-chemical properties. We note that the MTT estimated scanner is higher than the MTT estimated in Ultrasound, probably because of the phenomena of extravascular diffusion of the iodinated contrast used in CT scan. In a third study, we used the Sonovue ® to study the effect over time of intra-arterial embolization with micro-particles loaded with Adriamycin (DC-beads ®), compared to uncharged micro-particles (Bead Block ®). This study demonstrated the weaknesses of a radiological investigation based solely on size criteria, whatever major axis of tumors (RECIST) or estimating of the size of viable tumor (EASL criteria, usually used in cases CHC). This study also demonstrated the performance of a mixed evaluation, based on morphological and functional data, which is able to significantly differentiate the two treatment groups. On molecular imaging, we followed a protocol to separate several preliminary steps that have been validated: We experimented on two mice in contrast ultrasonography, in five successive injections of contrast, the reproducibility of retro-orbital injection. This reproducibility appeared sufficient to consider administering microbubbles targeted in this way, with a coefficient of variability below 20% on successive injections by quantification of the peak enhancement value on tumors of two mice. Fonctionnal imaging is therefore essential in evaluating therapies acting on angiogenesis, in case of anti-angiogenic treatment or endovascular arterial thérapie. We have shown that molecular imaging is not suited to the study of all tumor models: indeed it requires a strong expression of the molecular target inside the tumor endothelium so that the marking is detectable by the usual ultrasound imaging. Moreover, it is restricted to the study of tumor lesions located outside parenchymas accumulating microbubbles even in the absence of targeting, such as the spleen, liver and even kidney.Apart from these reserves, molecular imaging seems able to find a place for detection, or characterization of tumor of superficial organs such as thyroid, breast, or accessible by endo luminal way as prostate or pancreas

No description available.

The rising incidence of small, asymptomatic renal tumours discovered usmg abdominal imaging during the investigation of unrelated symptoms has fuelled the desire for new therapies which avoid surgical excision. Extracorporeal High Intensity Focused Ultrasound (HIFU) was proposed as one of these modalities but so far clinical research has been ,~." inconclusive. The present work was designed to improve these clii teal outcomes through the conduct of further clinical trials, laboratory based research and the translation of new technology into existing HIFU devices. A Phase II clinical trial of patients (n=13) with newly diagnosed <4cm renal tumours (clinical stage T1a) was designed, peer reviewed and received ethical approval (Ox REC 09/H0606104). Ten of 13 patients underwent renal HIFU using a clinical HIFU device (Model JCIJC200, HAIFU, China). One patient could not be treated due to poor tumour visualisation after anaesthesia and two patients could not be treated as they became unwell before or during anaesthesia. Histological evidence of HIFU ablation in either tumour or normal renal parenchyma was seen in all ten patients. Evidence of sub-total tumour ablation was seen in 8/10 of patients. Grade 1 «50%), 2 (50-90%) & 3 (90-99%) ablation was achieved in 4/10, 3/1 0 & 3/1 0 patients respectively but complete (100%) tumour ablation was not possible. HIFU treatment caused minimal morbidity - no Grade III- V (Clavien-Dindo) complications related to HIFU treatment occurred. Grade I skin pain and induration was seen in 9/1 0 patients; Grade II skin pain occurred in a single patient. Patient demographics, imaging and tumour characteristics were used to design parameters to improve patient selection for renal HIFU. The tumour location, thickness of peri-nephric fat and renal nephrometry score were useful predictors of successful screening for treatment. Page /ii Dr R. W Ritchie Nutiield Department of Surgical Sciences - TT 2012 Abstract Diligent use of these factors could limit unnecessary treatments and Improve ablation outcomes. , It is well known that ultrasound imaging of small renal masses can be challenging. Ultrasound imaging often deteriorates further during HIFU as the abdominal wall and fat tissues swell and cause increased attenuation. This loss of imaging quality was clearly demonstrated in this clinical trial and resulted in the early termination of treatment, before ,#,J' ... ~ .•.. endpoints were reached, in a number of cases. The current clinical method for monitoring the success of HIFU ablation using hyperecho analysis of B-mode ultrasound images is also questionable. Laboratory based studies using ex-vivo bovine liver subjected to HIFU confirmed that hyperecho monitoring had low sensitivity, predictive values and overall accuracy. A novel method of HIFU monitoring - passive mapping of the emissions received from acoustic cavitation activity and other sources of non-linearity during HIFU treatment - is believed to represent a significant opportunity to improve feedback. This technique uses the passively received signature of cavity activity which, when time-reversed, gives high- resolution images of the precise location of the activity. Laboratory-based ex-vivo work, using a commercially available ultrasound system (z.one, Zonare, USA), demonstrates its superiority over hyperecho monitoring. Indeed, thresholds could be applied to successfully predict HIFU ablation with high sensitivity and specificity. This technique was successfully translated into the clinical setting through the design of a Passive Acoustic Mapping (P AM) device. Custom-built receiving elements were applied without limiting the function of the existing HIFU devices. Both pre-clinical and ethically- Page [iii Dr R. W Ritchie Nuffield Department of Surgical Sciences - TT 2012 Abstract approved clinical studies demonstrated its safe integration without significant impact on the device energy output or treatment accuracy. Using similar passive beamfonning algorithms, acoustic cavitation activity was successfully mapped and corresponded with the location of thermal ablation in both ex-vivo tissue phantoms and during clinical HIFU therapy. ,~-' It is believed that the development of new patient selection paral~~tel's will elimil?ate target those patients who are most suitable for renal HIFU - small tumours, minimal peri-nephric fat & low nephrometry score .. The use of P AM will lead to a significant improvement in the efficacy of treatment. It can be successfully applied to existing devices and predicts the location and extent ofHIFU ablation with greater accuracy that existing techniques.

Wave transport in strongly scattering, disordered media is investigated experimentally using ultrasonic techniques. Several cases of anomalous wave transport (deviations from conventional diffusion) are studied through experiments on aluminum mesoglass samples, which were designed and created for this purpose. The anomalous wave behaviour is contrasted with conventional diffusion, observed at some frequencies via both transmission and backscattering measurements on wide, thick, slab-shaped samples. The coherent backscattering (CBS) effect is measured experimentally for strongly scattered acoustic waves in three dimensions (3D), and is compared for the first time with theory for diffusive elastic waves in 3D to give an estimate of the diffusion coefficient. At other frequencies, an Anderson localization regime is observed, and is studied in detail. The first experimental study of CBS for localized elastic waves in 3D is presented. By comparing both backscattering and transmission measurements with predictions from a ‘local’ self-consistent theory of localization, the first experimental observation of a complete Anderson mobility gap for elastic waves in 3D is reported. In this mobility gap, large contributions to backscattered intensity from recurrent scattering were observed, enabling the first experimental study of recurrent scattering on its own. The time-dependence of the recurrent scattering, R(t), is shown to agree with theoretical predictions in the diffuse and localized regimes. At the mobility edge, R(t) shows a surprisingly slow decay, prompting further theoretical work. Localization and criticality are also investigated via statistical measurements of ultrasound from cubic mesoglasses of different sizes. Finite-size scaling of multifractal quantities is observed in these cubic samples, and a preliminary fit with theory to determine critical parameters of the Anderson transition is demonstrated. Finally, a sample is which is a candidate to exhibit superdiffusion of ultrasound is studied via a range of experimental techniques, showing subtle deviations from diffusion and opening doors for the next steps in this study. / May 2016

Para o aperfeiçoamento das técnicas existentes e para o desenvolvimento de novas técnicas de diagnóstico por ultrassom equipamentos dedicados à pesquisa são necessários. Esses equipamentos devem possibilitar controle total da forma de excitação dos elementos piezoelétricos e acesso aos dados recebidos na sua forma pré-processada. Apesar de existirem equipamentos com essa finalidade, alguns deles ainda são limitados em relação aos controles de emissão e acesso aos dados raw por permitirem acesso apenas após a realização de um beamforming de recepção, como a aplicação de soma e atraso e apodização. Outro fator relevante sobre as máquinas voltadas para a pesquisa é o seu alto custo. Nesse projeto foi proposto um sistema de ultrassom de 8 canais, open source voltado à pesquisa, permitindo assim que seja reduzido o custo relacionado a propriedade intelectual do equipamento, e que permita controle completo dos parâmetros de emissão e recepção das ondas acústicas. Esse sistema de ultrassom foi construído utilizando kits de desenvolvimento comerciais. Os resultados adquiridos mostram que foram alcançadas variações de frequência de emissão de 1,79 MHz a 50 MHz, controles dos atrasos de emissão para controle de focalização dinâmica com resolução de 10 ns, controle de codificação do pulso, amplitude de excitação entre 10 e 140 V e acesso aos mapas RF na forma pré-processada, amostrados à uma frequência de 40 MHz. Os mapas de pressão acústica máxima foram adquiridos para diferentes profundidades de foco utilizando um hidrofone agulha e as imagens obtidas foram similares às simuladas anteriormente no software K-Wave. A etapa de recepção permitiu o acesso aos dados pré-beamforming de recepção, possibilitando o uso em técnicas que utilizam reconstrução por reversão no tempo, por exemplo. O sinal recebido utilizando o código desenvolvido permaneceu com aquisição incorreta de algumas amostras devido à problemas de timings internos do controlador do sistema que precisam ser corrigidos. Ao final do projeto foi demonstrada a utilização da plataforma construída na modalidade de imagem de fotoacústica. / In order to improve existed techniques and to help the development of new diagnostic techniques for ultrasound, research ultrasound equipment is needed. This equipment is focused on providing flexibility for those who involved in improvement of existing and new diagnostic techniques for ultrasound imaging. However, most of the equipment dedicated to research are expensive and sometimes do not provide unrestricted access to the very basic level. For instance, the full control of the form of excitation of piezoelectric elements and accessing to pre-beamformed data are two examples. For this purpose, we developed an 8-channel, open source ultrasound system to overcome beamforming limitations, providing access to raw data before sum-and-delay and apodization. Our purpose was focused on providing an open source ultrasound research system in which we reduced the high-cost related to intellectual property of the commercial available equipment. The system developed allows complete control of emission parameters and reception of acoustic waves, which permitted variations in transmission frequency of 1.79 MHz to 50 MHz, dynamic focusing with 10 ns resolution, pulse coding control, amplitude excitation with range 10 V to 140 V and access to pre-processed signals sampled with 40 MHz frequency. The effects of different configurations were evaluated acquiring sound pressure maps. The maps obtained were in agreement with simulated pressure maps, which were generated using K-Wave software. One example is presented in the project from the evaluation of the system in photoacoustic application. The data acquired were used for reconstruction of photoacoustic imaging, using time-reversal reconstruction. Nevertheless, due to internal system timing, a sampling problem during acquisition needs to be corrected. Although, at the end of the project, a photoacoustic imaging was provided to demonstrate the systems functionality.

Acoustic levitation is a method which uses sound radiation to suspend matter in a medium. The main use of this phenomenon is for the contactless processing of matter, allowing to manipulate small objects without any solid contact. Contactless processing of matter presents many advantages in, for example, the fabrication of MEMS (microelectromechanical systems) where handling the components is challenging because of their fragile and surface-sensitive characteristics or in the chemical/biological industry when handling high-purity or hazardous materials. Thus, a new device for noncontact linear transportation of small solid objects is presented here. In this device, ultrasonic flexural vibrations are generated along the ring shaped vibrator using two Langevin transducers and by using a reflector parallel to the vibrator, small particles are trapped at the nodal points of the resulting acoustic standing wave. The particles are then moved by generating a traveling wave along the vibrator, which can be done by modulating the vibration amplitude of the transducers. The working principle of the traveling wave along the vibrator has been modeled by the superposition of two orthogonal standing waves, and the position of the particles can be predicted by using finite element analysis of the vibrator and the resulting acoustic field. A prototype consisting of a 3 mm thick, 220 mm long, 50 mm wide and 52 mm radius aluminum ring-type vibrator and a reflector of the same length and width was built and small polystyrene spheres have been successfully transported along the straight parts of the vibrator. / Levitação acústica é um método para suspender matéria em um meio através de pressão de radiação acústica gerada por intensas ondas de som. O principal uso desse fenômeno é na manipulação de partículas sem contato solido. Esse fenômeno tem várias aplicações para pesquisas onde deve ser evitado todo o contato como, por exemplo, na área de biologia, química, e na fabricação de MEMS. Assim, um novo sistema de transporte linear de partículas por levitação acústica está apresentado aqui. Nesse sistema, vibrações flexurais estão geradas em uma placa tipo anel com dois transdutores tipo Langevin, e colocando um refletor paralelo ao oscilador, partículas estão presas no pontos nodais da onda acústica gerada. As partículas estão deslocadas modulando a amplitude dos transdutores. Assim, este trabalho tem como objetivos a modelagem do fenômeno de levitação acústica, o dimensionamento de um protótipo de sistema de transporte linear de partículas por levitação acústica, bem como a fabricação e o controle desse protótipo. Um protótipo consistindo de uma estrutura tipo anel de alumínio de 3 mm de espessura, 220 mm de comprimento e um raio de 52 mm foi fabricado e o transporte de pequenas esferas de isopor foi realizado com êxito nas parte retas do vibrador.

Nesta pesquisa estudou-se a soldagem de materiais poliméricos por ultra-som, sendo estes, policarbonato (PC) e poli(metacrilato de metila, PMMA. As soldagens foram obtidas através do equipamento especifico para soldagem Soldadoras Integradas, série 900IW, empresa BRANSON Ultrasonics Corporation. Onde detalhamos alguns aspectos do equipamento: mecanismo de soldagem, conversores, transformador e sonotrodo. Para o sonotrodo especificamos a relação de área em função da geometria do mesmo. Ressaltamos também os tipos de métodos de soldagem: direto e indireto, de forma que concluímos que os materiais semicristalinos devem ser soldados apenas pelo método direto em conseqüência destes apresentarem grande perda de amplitude durante a soldagem. Em função destes possuírem uma acentuada queda do módulo de cisalhamento (G) e um aumento no fator de perda mecânica Tang &#948; acima da temperatura de transição vítrea (Tg), o que prejudica a soldagem. Foram analisados outros fatores que influem no processo de soldagem da junta como: tipos de juntas para uma melhor transmissão de energia, onde verificamos que juntas que possuem um D.R (diretor de energia) apresentam uma boa soldagem, diferente o que acontece com superfícies planas que apresentaram uma soldagem inadequada. Pesquisou-se também a propagação da onda no diretor de energia onde verificamos variações da amplitude através do mesmo. Estudou-se o método para estimar a capacidade de soldagem por ultra-som dos matérias através de fórmulas, onde verificou-se resultados coerentes com os valores reais. Experimentalmente variou-se os parâmetros de soldagem tais como: tempo de soldagem, pressão, e o tempo de recalque, com o intuito de obter-se variações na área soldada e na resistência ao cisalhamento das juntas. Os resultados apresentados pela variação dos parâmetros foram significativos, de modo, que o aumento do tempo de soldagem influenciou em um aumento da área das amostras em 90% das soldagens realizadas, tanto para soldagens similar (de mesmo material) e dissimilar (de materiais diferentes). Com aumento da pressão de soldagem obtivemos resultados menos significativos, ou seja, verificamos que 86,52% das amostras com junção similar, aumentaram a área em função do aumento da pressão. Os outros 13,48% diminuíram a área soldada em função do aumento da pressão, fenômeno causado pela diferença de rechupe encontrado nas amostras injetadas. O aumento do tempo de recalque não apresentou variações de área e de resistência ao cisalhamento significativas. As amostras soldadas apresentam o fenômeno de esbranqueceamento da região unida, onde concluímos que a umidade presente no material e as microrugosidades presentes na superfície do mesmo, causam este fenômeno. O qual pode ser minimizado através de secagem do material antes da injeção. Mediu-se a área soldada, e a resistência ao cisalhamento de todos os tipos de juntas, de forma que obtivemos diferentes valores para cada tipo de material analisado (PMMA e PC) com junções similares (PMMA/PMMA e PC/PC), dissimilares (PMMA/PC) e com direções de injeção similares (HH, VV) e direção de injeção dissimilar (HV). Com estes resultados podemos aplicar o método estatístico de análise de variância em função da variação de área e da variação de resistência. Os resultados da análise de variância foram mais coerentes com os resultados experimentais em função do parâmetro tempo de soldagem. A análise de variância em função da pressão apresentou resultados menos significativos, comparado aos resultados experimentais. As juntas soldadas foram adaptadas da norma ASTM D638M, e para realização do teste de cisalhamento projetou-se um dispositivo especial para esta aplicação. / In this research it was studied welding of polymerics materials by ultrasound, being these, polycarbonate (PC) and poli(metacrilate of metila, PMMA). The weldings had been gotten through the equipment specify for welding (Integrated Soldering, series 900IW, company BRANSON Ultrasonics Corporation). Detail some aspects of the equipment: mechanism of welding, converters, transforming and sonotrode. For sonotrode we specify the relation of area in function of the geometry. Empathized also two types of welding methods: direct and indirect, then we conclude that the semi crystalline materials must be welded only by the direct method, in consequence of these materials to present great loss of amplitude during the welding. In function of these to possess one accented fall of the module of shear (G) and an increase in the mechanics loss factor (Tang &#948;), above of the glass transition temperature (Tg), these factors it harms the welding. Other factors had been analyzed that influence in the process of welding of the joining, as: geometric of joining for one better transmission of energy, where we verify that joining that possess a D.R (director of energy) these present a good welding, different of others joining with plain surfaces that had presented an inadequate welding. The propagation of the wave in the energy director was also searched where we verify variations of the amplitude through D.R. The method was studied for estimate of the capacity of welding for ultrasound of the materials through formulas, where it was verified coherent resulted with the real results. Experimentally varied the welding parameters such as: welding time, pressure, and the time pressure after welding, with intention to get variations in the welded area and the shear strength of the joining. The results presented for the variation of the parameters had significant, in way, that the increase of the welding time influenced in an increase of the area of the samples in 90% of the carried through weldings, as much for weldings similar (of same material) and dissimilar (of different materials). With increase of the welding pressure we got resulted less significant, or either, we verify that 86.52% of the samples with similar junction, had increased the area in function of the increase of the pressure. The others 13.48% had diminished the area welded in function of the increase of the pressure, phenomenon caused for the difference of contraction found in the injected samples. The increase of the time of the time pressure after welding did not present variations of area and significant shear strength. The welded samples present the phenomenon of change of color of the joined region, where we conclude that the present humidity in the material and the microrugosidades of the surface causes this phenomenon. The change color can be minimized through drying of the material before the injection. It measured welded area, and the shear strength of all the types of joining, and this form we got different values of area and of shear strength for each type of material analyzed (PMMA and PC) with similar junctions (PMMA/PMMA and PC/PC) and dissimilar (PMMA/PC) with similar directions of injection (HH, VV) and direction of dissimilar injection (HV). With these results we can apply the statistical method of analysis of variance in function of the variation of area and in function of the variation of resistance. The results of the variance analysis had been more coherent with the experimental results in function of the parameter welding time. The analysis of variance in function of the pressure presented resulted less significant, comparative to the experimental results. The welded joining had been adapted according to norm ASTM D638M, and for development of the shear test a special device for this application was projected.

A finalidade deste trabalho foi obter suspensões aquosas estáveis de beta-quitina (GA = 79%) explorando o uso de ultrassom de alta intensidade, e preparar filmes autossuportados por casting a partir de suspensões de beta-quitina, soluções aquosas de quitosana (GA = 4,9%) e da combinação de ambas em diferentes proporções. Assim, foram preparados os filmes BQF (100% beta-quitina) e QF (100% quitosana), e os filmes compostos BQ80/Q20, BQ50/Q50, BQ20/Q80, sendo que as porcentagens de beta-quitina e quitosana são indicadas pelos sub-índices empregados na identificação dos referidos filmes. Foi constatado por análises de espectroscopia na região do infravermelho e espectroscopia de ressonância magnética nuclear de hidrogênio que o tratamento de ultrassom não alterou a estrutura de beta-quitina, enquanto a viscosimetria capilar em solução diluída mostrou ligeiro decréscimo (16%) da viscosidade intrínseca, indicando a ocorrência de despolimerização em baixa extensão. As análises de microscopia eletrônica de varredura e microscopia de força atômica mostraram que os filmes com maiores teores de beta-quitina exibiram superfícies mais heterogêneas, granulares e rugosas, enquanto a presença de quitosana resultou em filmes mais homogêneos e significativamente menos rugosos. Assim, os filmes BQF e QF apresentaram valores de rugosidade média quadrática (RMS) 225,0 nm e 21,6 nm , respectivamente. As medidas de ângulo de contato revelaram que o filme QF é o mais hidrofílico (&theta; &asymp; 75,40), enquanto os filmes compostos BQ20/Q80, BQ50/Q50 e BQ80/Q20, que têm teores crescentes de beta-quitina, foram mais hidrofóbicos, apresentando ângulos de contato 87,50, 95,60 e 95,20, respectivamente. As análises termogravimétricas revelaram que o tratamento de ultrassom favorece o intumescimento das partículas de beta-quitina e que o baixo grau de ordem dos filmes contribui para diminuir a estabilidade térmica quando comparada à beta-quitina na forma de pó. As análises de calorimetria exploratória diferencial dos filmes compostos mostraram que a eliminação de água demanda maior energia quanto maior o teor de beta- quitina, evidenciando a ocorrência de fortes interações entre as cadeias de beta-quitina e moléculas de água. Assim, os resultados mostraram que o tratamento de ultrassom permitiu o processamento de beta-quitina/quitosana para a formação de filmes autossustentados sem a utilização de solventes orgânicos, e que os filmes exibem características e propriedades que dependem fortemente de sua composição, i. e. dos teores de beta-quitina e quitosana. / The purpose of this study was to obtain stable aqueous suspensions of beta-chitin (GA = 79%) exploring the use of high intensity ultrasound, and to prepare self-sustained films by casting from suspensions of beta-chitin, chitosan aqueous solutions (GA = 4.9%) and from the combination of both, in different proportions. Thus, the films BQF (100% of beta-chitin) and QF (100% of chitosan) and compound films BQ80/Q20, BQ50/Q50, BQ20/Q80 were prepared, the percentages of beta-chitin and chitosan being indicated by the sub-indices used in the identification of those films. It has been found by infrared spectroscopy and proton nuclear magnetic resonance spectroscopy that the ultrasound treatment did not alter the structure of beta-chitin, while the capillary viscometry in dilute solution showed a slight decrease (16%) of intrinsic viscosity indicating the occurrence of depolymerization at low extension. Atomic force microscopy and scanning electron microscopy showed that the films with higher content of beta-chitin exhibited more heterogeneous, granular and rough surfaces, while the presence of chitosan resulted in significantly more homogeneous and less rough films. Thus, QF and BQF films showed values of mean square roughness (RMS) 225.0 nm and 21.6 nm, respectively. The contact angle measurements showed that QF (&theta; &asymp; 75.40) is the more hydrophilic film, while the composite films BQ20/Q80, and BQ50/Q50, BQ80/Q20, which have increasing contents of beta-chitin were more hydrophobic, exhibiting contact angles 87.50, 95.60 and 95.20, respectively. Thermogravimetric analysis showed that the ultrasound treatment favored the swelling of the particles of chitin and that the low degree of order of the films contributed to decrease the thermal stability when compared to beta-chitin in powder form. The differential scanning calorimetry of the compound films showed that the elimination of water requires more energy the higher the content of beta-chitin, indicating the occurrence of strong interactions between the chains of beta- chitin and water molecules. Thus, the results showed that the ultrasoud treatment allowed the processing beta- chitin/chitosan for the formation of self-sustained films without the use of organic solvents, and that the films exhibited characteristics and properties strongly dependent on their composition, i. e. the content of beta-chitin and chitosan.