No description available.

Around 40 million people around the world have amputated parts of their bodies. Prostheses are widely used to support their daily behavior. However, about 35% of amputees refuse to use the prostheses due to comfort problems. SocketSense is an EU research project that aims to improve the situation. The Stewart platform (SP) is used as the model of the prototype. The SP could reproduce the comparing forces and torques interior the socket-to-stump interface, given prerecorded movement information of an amputee’s walk cycle. However, previous work controls SP based on inputting some simple reference trajectories ,or for radar, satellite and vehicle use-cases. This  thesis is committed to designing and implementing a control algorithm for the SP to control the socket. The task is divided into two main parts: simulation on Matlab/Simulink and implementation on Linux/ROS, and each part is split into several steps. Firstly, the PID control algorithm is selected and developed for the SP. Secondly, the simulation model is designed and built on Matlab/Simulink. Based on the simulation model, the control algorithm is implemented into the model. Then, the results of simulation are obtained. After that, the SP model is built on Linux/ROS. Then, the model is connected and communicated with the real platform. Finally, the output data and system performance are analysed in terms of control performance, real-time performance, anti-noise performance, etc. The results show that both the simulation and the actual platform system can follow the reference trajectory well. Although there is noise in the results of the actual platform, the noise is suppressed to a great extent by Kalman filter. / Runt 40 miljoner människor runtom i världen har amputerat delar av sina kroppar. Proteser används ofta för att stödja deras dagliga beteende. Emellertid vägrar cirka 35% av amputerade att använda proteserna på grund av komfort problem. SocketSense är ett EU-forsknings projekt som syftar till att förbättra situationen. SP används som modell för prototypen. SP skulle kunna återskapa de jämförande krafterna och vridmomenten inuti gränssnittet uttag-till-stump, givet förinspelad rörelseinformation om en amputerads gångcykel. Tidigare arbete styr dock SP baserat på att ange några enkla referensbanor, eller för radar-, satellit-och fordonsanvändningsfall. Detta examensarbete syftar till att designa och implementera en kontroll algoritmför SP för att styra socket. Uppgiften är uppdelad i två huvuddelar: simulering på Matlab/ Simulink och implementering på Linux/ROS, och varje del är uppdelad i flera steg. Först väljs och utvecklas PID-kontrollalgoritmen för SP. För det andra är simuleringsmodellen designad och byggd på Matlab/ Simulink. Baserat på simuleringsmodellen implementeras styralgoritmen i modellen. Därefter erhålls resultaten av simuleringen. Därefter är SP-modellen byggd på Linux/ROS. Sedan kopplas modellen ihop och kommuniceras med den verkliga plattformen. Slutligen analyseras utdata och systemprestanda i termer av kontrollprestanda, realtidsprestanda, anti-brusprestanda, etc. Result visar att både simuleringen och det faktiska plattformssystemet kan följa referensbanan väl. Även om det finns brus i resultaten av själva plattformen, dämpas bruset i hög grad av Kalman-filter.

(1) Background: Hemodynamic assessment of prosthetic heart valves using conventional 2D transthoracic Echocardiography-Doppler (2D-TTE) has limitations. Of those, left ventricular outflow tract (LVOT) area measurement is one of the major limitations of the continuity equation, which assumes a circular LVOT. (2) Methods: This study comprised 258 patients with severe aortic stenosis (AS), who were treated with the ACURATE neo2. The LVOT area and its dependent Dopplerderived parameters, including effective orifice area (EOA) and stroke volume (SV), in addition to their indexed values, were calculated from post-TAVI 2D-TTE. In addition, the 3D-LVOT area from pre-procedural MDCT scans was obtained and used to calculate corrected Doppler-derived parameters. The incidence rates of prosthesis patient mismatch (PPM) were compared between the 2D-TTE and MDCT-based methods (3) Results: The main results show that the 2D-TTE measured LVOT is significantly smaller than 3D-MDCT (350.4 62.04 mm2 vs. 405.22 81.32 mm2) (95% Credible interval (CrI) of differences: 55.15, 36.09), which resulted in smaller EOA (2.25 0.59 vs. 2.58 0.63 cm2) (Beta = 0.642 (95%CrI of differences: 0.85, 0.43), and lower SV (73.88 21.41 vs. 84.47 22.66 mL), (Beta = 7.29 (95% CrI: 14.45, 0.14)), respectively. PPM incidence appears more frequent with 2D-TTE- than 3D-MDCT-corrected measurements (based on the EOAi) 8.52% vs. 2.32%, respectively. In addition, significant differences regarding the EOA among the three valve sizes (S, M and L) were seen only with the MDCT, but not on 2D-TTE. (4) Conclusions: The corrected continuity equation by combining the 3D-LVOT area from MDCT with the TTE Doppler parameters might provide a more accurate assessment of hemodynamic parameters and PPM diagnosis in patients treated with TAVI. The ACURATE neo2 THV has a large EOA and low incidence of PPM using the 3D-corrected LVOT area than on 2D-TTE. These findings need further confirmation on long-term follow-up and in other studies.

No / Epidemiologic research has shown that multifocal spectacle wearers (bifocal and progressive addition lenses [PALs]) are more than twice as likely to fall than are nonmultifocal spectacle wearers, with this risk further increasing when negotiating stairs. The present study investigated whether step and stair descent safety is improved by using single-vision distance lenses. METHODS: From a stationary standing position on top of a block, 20 long-term multifocal wearers stepped down (from different block heights) onto a lower level wearing bifocal, progressive addition, or single-vision distance lenses. RESULTS: Use of single-vision distance spectacles led to an increased single-limb support time, a reduced ankle and knee angle and vertical center-of-mass velocity at contact with the lower level, and a reduced ankle angular velocity and vertical center-of-mass velocity during initial landing (P < 0.03). These findings indicate that landing occurred in a more controlled manner when the subjects wore single-vision distance spectacles, rather than tending to "drop" onto the lower level as occurred when wearing bifocals or PALs. CONCLUSIONS: Use of single-vision distance spectacles led to improvements in landing control, consistent with individuals' being more certain regarding the precise height of the lower floor level. This enhanced control was attributed to having a view of the foot, step edge, and immediate floor area that was not blurred, magnified, or doubled and that did not suffer from image jump or peripheral distortions. These findings provide further evidence that use of single-vision distance lenses in everyday locomotion may be advantageous for elderly multifocal wearers who have a high risk of falling.

Einen Orbitadefekt mit Verlust des Auges und der filigranen Lidstrukturen kann eine implantatverankerte Silikonepithese im Halt sicher und bei geöffnetem Auge ästhetisch mit gutem Ergebnis abdecken. Bei Lidschluß fällt allerdings die Starrheit der Lider in der Epithese auf. Ziel der Entwicklung war es, das künstliche Oberlid in der Orbitaepithese beweglich zu gestalten und so durch die gewonnene Dynamik ein natürlicheres Aussehen beim Patienten zu erreichen. In der Epithese sollten alle Komponenten integriert sein, um das künstliche Oberlid synchron zum gesunden Auge zu bewegen. Als bewegliches Oberlid erwies sich gegossene Latexmilch als Material am geeignetsten. Dieses Material war elastisch, einfärbbar und konnte den Belastungen der ungefähr 30 unwillkürlichen Lidschlagbewegungen pro Minute standhalten. Das künstliche Oberlid wurde analog dem natürlichen Vorbild des Lidöffners nach dem Prinzip der Zuggurtung über die Augenprothese nach oben hinten gezogen. Als Antrieb wurde ein DC-Mikromotor eingesetzt, der das Oberlid mit Hilfe eines kleinen Polyamidfadens, welcher an der inneren verstärkten Lidkante befestigt war, nach kranial bewegte. Der Faden wurde über eine Kanülenführung auf eine Seilrolle gewickelt. Nachdem sich ein aufgebautes Tischmodell im Test bewährt hatte, wurde eine einbaufähige elektronische Schaltung in SMD-(Surface Mounted Device) Technik entwickelt, die einerseits den Antrieb steuerte und andererseits die zur Synchronisation erforderlichen Muskelpotentiale verarbeitete. Diese zwei doppelseitig bestückten Platinen wurden direkt hinter die individuell aus Glas vom Okularisten hergestellte Augenprothese positioniert. Über fünf integrierte einstellbare Potentiometer konnten die abgeleiteten Muskelsignale für eine verzögerungsfreie Lidbewegnung beim Patienten individuell verändert werden. Die Energiebereitstellung für die Elektronik und den Motor konnte aufgrund der zu niedrigen Nennkapazitäten nicht durch Akkumulatoren erfolgen, sondern wurde durch eine kleine leicht auswechselbare Batterie erreicht, die hochgerechnet Strom für 7 bis 14 Tage lieferte. Da die einzelnen Komponenten nicht frei in der Epithese liegen konnten, wurde als Schutz ein Gehäuse in hartem Acrylatkunststoff konzipiert. Da die Anordnung der Batterie unter oder hinter dem Motor möglich war und auch die Elektronik versetzt zu Batterie und Motor angebracht werden konnte, konnte so die Geometrie des Gehäuses in Grenzen dem individuellen Orbitadefekt angepaßt werden. In klinischen Versuchen an gesunden Probanden und Patienten mit implantatverankerten Orbitaepithesen zeigte sich, daß Muskelpotentiale vom M. orbicularis oculi aus dem gesunden Oberlid oder teilweise der exenterierten Orbita mit Restaktivität des Lidschließers mit Nadelelektroden bipolar abgeleitet zur Ansteuerung des Motors geeignet waren. Mit diesen Biopotentialen wurde das reibungslose Funktionieren der synchronen Lidbewegung des Prototypen an einer freiwilligen gesunden Versuchsperson getestet. Nach umfangreichen Labortestungen wurden zwei Patienten mit dieser neuartigen Orbitaepithese rehabilitiert. Bei den Patienten wurde das passende Gehäuse mit den gekapselten Funktionseinheiten individuell hergestellt und dieses in eine Silikonepithese eingearbeitet. Gehalten wurde die Silikonepithese über implantatfixierte Magnetabutments. Die Muskelpotentialableitung zur Triggerung der synchronen Lidbewegung erfolgte durch eine intramuskuläre EMG - Ableitung des M. orbicularis oculi. Beim ersten Patienten gelang dieses über eine sterile Nadelelektrode, die allerdings beim Tragen der neuen Orbitaepithese jedes Mal neu in den Muskel eingestochen werden mußte. Beim zweiten Patienten wurden die Muskelpotentiale über eine subcutan implantierte dünne EMG - Elektrode aufgenommen. Die Myosignale wurden bei beiden Patienten bipolar abgeleitet. Die zweite differente Elektrode kontaktierte einen implantatfixierten Magneten. Die Neutralelektrode war mit einem weiteren implantatverankerten Magneten verbunden. Die abgeleiteten Muskelimpulse beim Lidschlag konnten so bei den Patienten eine zum gesunden Oberlid synchrone künstliche Lidbewegung initiieren. Da die Bauteile zur künstlichen Lidbewegung noch nicht beliebig klein zu gestalten sind, können zur Zeit noch nicht alle Orbitaepithesenträger mit der neuartigen Epithese rehabilitiert werden. Um bei Patienten mit kleineren Orbitadefekten die Epithese eingliedern zu können, muß sich die zukünftige Forschung auf eine noch weitere Größenreduktion der einzelnen Komponenten konzentrieren. Durch die Entwicklung von telemetrischen Verfahren wird es möglich sein, die von einer intramuskuären implantierten, für diese Anwendung optimierten EMG - Elektrode emfangenen Signale ohne infektionsgefährdete Hautdurchleitung zur Epithese zu übertragen. / An orbit defect with loss of the eye and its delicate lid structures can be concealed with an implant anchored silicon facial prosthesis. This method assures secure retention and good esthetic results as long as the eye remains open. However, when the healthy lid closes, the immobility of the prosthesis becomes conspicuous. The aim of this development was to animate the artificial lid in the orbita prosthesis to give the patient a much more natural appearance. All components in the prosthesis were integrated to create an artificial lid that would blink in synchrony with that of the healthy eye. The material which proved to be most suited for the moveable eyelid was cast latex milk. It was elastic, would take dyes and was robust enough to withstand approximately 30 involuntary lid movements per minute. The artificial upper lid was pulled up behind the eye prosthesis by means of a fine thread, analogous to the natural lid opener. This is driven by a DC micromotor which lifts the upper lid in a cranial direction with a polyamid thread attached to the reinforced rim of the lid. The thread was wound onto a minute pulley. After a successful model had been constructed, an electronic circuit was developed in SMD (Surface Mounted Device) technique which drove the motor and processed the muscle potential necessary for the synchronization. These two double-sided circuit boards were positioned directly behind the artificial eye, which had been created specially by an ophthalmologist. By means of five integrated potentiometers, the muscle signals picked up were individually modified and adjusted to eliminate any delays in the lid movement. The low nominal capacity provided by accumulators ruled them out as a possible power supply for the electronics and motor, and instead, a small, light replaceable battery, capable of powering the motor for 7 to 14 days, was chosen. The individual components were then assembled and housed in a case of rigid acrylate plastic. It was possible to position the battery either under or behind the motor and to and stagger the electronics parts to the position of the battery and motor. This enhanced the adaptability of the case's geometric form to the individual orbit defect. Clinical tests with healthy test persons and patients with implant-anchored orbital prostheses demonstrated that muscle potentials from the orbicularis oculi muscle could be picked up from the healthy upper lid with bipolar needle electrodes. This was also possible in some cases when after exenteration the orbicularis oculi muscle remained partially active and continued to emit muscle potentials. With these biopotentials, the synchronic lid movement of the prototype was tested on a voluntary healthy test person. It functioned flawlessly. After extensive laboratory tests, two patients were rehabilitated with the new orbita prosthesis. For each patient a case for the components was designed and fitted into a silicone prosthesis retained with implant-anchored magnet abutments. The muscle potentials were conducted by an intramuscular electromyography (EMG) to trigger synchronous lid movement. With the first patient, a sterile needle electrode was used, but this had to be reinserted into the muscle each time the prosthesis was fitted. In the second patient the muscle potentials were picked up via a thin EMG-electrode implanted subcutaneously. In both cases bipolar conduction was taken. The second different electrode was attached to one implant-anchored magnet; the neutral electrode to another. In both patients, the muscle impulses emitted during lid closure initiated an artificial lid movement in synchrony with the healthy eyelid. Since the component parts cannot be reduced beyond a certain minimum size, not all orbit prosthesis wearers can be rehabilitated with the new prosthesis. In order to fit patients with smaller defects, future research will have to concentrate on a further reduction in component size. With further developments in telemetric procedures it will become possible to transmit signals received from a EMG electrode implanted in the muscle to the prosthesis without the dangers of infection inherent in conducting them through the skin.

A revascularização da oclusão arterial ilíaca crônica com implante de endoprótese vascular é uma nova modalidade terapêutica para os pacientes com aterosclerose obliterante das extremidades. Os objetivos deste trabalho são verificar: os resultados clínico e radiológico do tratamento percutâneo com implante de endoprótese vascular nas oclusões arteriais crônicas do território ilíaco; a influência da aterosclerose e seus principais fatores de risco; os principais sintomas clínicos segundo os estágios de Fontaine e o comportamento das endopróteses vasculares, avaliando as permeabilidades primária e secundária. Foram estudados 67 pacientes, com 69 oclusões arteriais ilíacas crônicas, submetidos a intervenção de janeiro de 1992 a dezembro de 1998, por meio de avaliação clínica, Doppler com medida do índice tornozelo/braço e arteriografia dos membros inferiores. As revascularizações arteriais ilíacas foram realizadas sob anestesia local, utilizando-se as endopróteses tipos Wallstent® e Cragg®. O índice de sucesso técnico foi de 97,10%. A mediana do período de internação foi de dois dias e as complicações mais importantes foram tromboses arteriais (2,99%), roturas arteriais (2,99%) e embolia poplítea (1,49%). O índice tornozelo/braço pré e pós-procedimento demonstrou um incremento, estatisticamente significante, após a intervenção (P = 0,0001), e os eventos durante o seguimento foram as estenoses (5,97%) e tromboses (8,96%) das endopróteses. Houve algum grau de melhora clínica em 92,5% dos pacientes. Os casos que não apresentaram melhora tiveram associação, estatisticamente significante, com cardiopatia associada (P = 0,003) e estágios III e IV de Fontaine (P = 0,022). Não houve associação, estatisticamente significante, entre os fatores analisados e permeabilidade das endopróteses vasculares. A revascularização percutânea com implante de endopróteses vasculares nas oclusões arteriais ilíacas crônicas, demonstrou apresentar bons índices de permeabilidades primária (75%) e secundária (95%) durante o período médio de 30 meses de acompanhamento. / Arterial recanalization with percutaneous transluminal angioplasty and implantation of a vascular endoprosthesis in an occluded iliac artery is a ew therapeutic modality for those patients with obliterative atherosclerosis of the extremities. The objectives of this work are to demonstrate the clinical and radiological results of treatment of chronic occlusions of the iliac arteries; to demonstrate the effects of atherosclerosis as well as primary risk factors; to evaluate the primary clinical symptoms using the Fontaine classification and to study the effectiveness of the vascular endoprostheses with primary and secondary patency rates. Sixty-seven patients with 69 chronically occluded iliac arteries underwent percutaneous intervention from January 1992 throught December 1998. Evaluations included clinical assessment, Doppler examinations with ankle/brachial indexes and bilateral lower extremity arteriograms. The iliac artery recanalizations were performed under local anesthesia and using Wallstent® and Cragg® vascular endoprostheses. Technical success rate was 97.10%. The mean hospitalization time was two days and major complications included arterial thrombosis (2.99%), arterial rupture (2.99%) and popliteal embolization (1.49%). The prior and post procedure ankle/brachial indexes demonstrated a statistically significant increase following intervention (P = 0.0001). During follow-up there was 5.97% of stenosis and 8.96% thrombosis of the endoprostheses. There was clinical improvement in 92.42% of patients. Patients that did not show clinical improvement had association with coronary disease (P = 0.003), Fontaine stages III and IV (P = 0.022) and arterial hypertension (P = 0.087). There was no statistically significant factor associated with lower patency of the endoprostheses. Percutaneous revascularization of chronically occluded iliac arteries with utilization of vascular endoprostheses has shown good primary (75%) and secondary (95%) patency rates during 30 months of mean follow-up period.

A revascularização da oclusão arterial ilíaca crônica com implante de endoprótese vascular é uma nova modalidade terapêutica para os pacientes com aterosclerose obliterante das extremidades. Os objetivos deste trabalho são verificar: os resultados clínico e radiológico do tratamento percutâneo com implante de endoprótese vascular nas oclusões arteriais crônicas do território ilíaco; a influência da aterosclerose e seus principais fatores de risco; os principais sintomas clínicos segundo os estágios de Fontaine e o comportamento das endopróteses vasculares, avaliando as permeabilidades primária e secundária. Foram estudados 67 pacientes, com 69 oclusões arteriais ilíacas crônicas, submetidos a intervenção de janeiro de 1992 a dezembro de 1998, por meio de avaliação clínica, Doppler com medida do índice tornozelo/braço e arteriografia dos membros inferiores. As revascularizações arteriais ilíacas foram realizadas sob anestesia local, utilizando-se as endopróteses tipos Wallstent® e Cragg®. O índice de sucesso técnico foi de 97,10%. A mediana do período de internação foi de dois dias e as complicações mais importantes foram tromboses arteriais (2,99%), roturas arteriais (2,99%) e embolia poplítea (1,49%). O índice tornozelo/braço pré e pós-procedimento demonstrou um incremento, estatisticamente significante, após a intervenção (P = 0,0001), e os eventos durante o seguimento foram as estenoses (5,97%) e tromboses (8,96%) das endopróteses. Houve algum grau de melhora clínica em 92,5% dos pacientes. Os casos que não apresentaram melhora tiveram associação, estatisticamente significante, com cardiopatia associada (P = 0,003) e estágios III e IV de Fontaine (P = 0,022). Não houve associação, estatisticamente significante, entre os fatores analisados e permeabilidade das endopróteses vasculares. A revascularização percutânea com implante de endopróteses vasculares nas oclusões arteriais ilíacas crônicas, demonstrou apresentar bons índices de permeabilidades primária (75%) e secundária (95%) durante o período médio de 30 meses de acompanhamento. / Arterial recanalization with percutaneous transluminal angioplasty and implantation of a vascular endoprosthesis in an occluded iliac artery is a ew therapeutic modality for those patients with obliterative atherosclerosis of the extremities. The objectives of this work are to demonstrate the clinical and radiological results of treatment of chronic occlusions of the iliac arteries; to demonstrate the effects of atherosclerosis as well as primary risk factors; to evaluate the primary clinical symptoms using the Fontaine classification and to study the effectiveness of the vascular endoprostheses with primary and secondary patency rates. Sixty-seven patients with 69 chronically occluded iliac arteries underwent percutaneous intervention from January 1992 throught December 1998. Evaluations included clinical assessment, Doppler examinations with ankle/brachial indexes and bilateral lower extremity arteriograms. The iliac artery recanalizations were performed under local anesthesia and using Wallstent® and Cragg® vascular endoprostheses. Technical success rate was 97.10%. The mean hospitalization time was two days and major complications included arterial thrombosis (2.99%), arterial rupture (2.99%) and popliteal embolization (1.49%). The prior and post procedure ankle/brachial indexes demonstrated a statistically significant increase following intervention (P = 0.0001). During follow-up there was 5.97% of stenosis and 8.96% thrombosis of the endoprostheses. There was clinical improvement in 92.42% of patients. Patients that did not show clinical improvement had association with coronary disease (P = 0.003), Fontaine stages III and IV (P = 0.022) and arterial hypertension (P = 0.087). There was no statistically significant factor associated with lower patency of the endoprostheses. Percutaneous revascularization of chronically occluded iliac arteries with utilization of vascular endoprostheses has shown good primary (75%) and secondary (95%) patency rates during 30 months of mean follow-up period.

Introdução: Apesar de bons resultados descritos na literatura, o substituto ideal para a utilização como remendo no fechamento arterial ainda não existe. Por este motivo, ainda há espaço para a busca por remendo que seja biocompatível, e que apresente facilidade de manuseio e resultados satisfatórios. Avaliamos remendos arteriais de silicone (polidimetilsiloxano com reforço em poliéster - PDMSr) em comparação com remendos arteriais de PTFEe. Objetivo: O objetivo deste trabalho é comparar, em modelo experimental, em coelhos, os resultados de remendos arteriais feitos em PDMSr com remendos de PTFEe. Materiais e Método: A amostra foi definida em 10 animais que completassem todas as etapas da pesquisa em cada grupo. Os animais foram submetidos à laparotomia mediana e abertura longitudinal da aorta de aproximadamente 8mm, realizando-se o seu fechamento com remendo do grupo selecionado, seguido do fechamento por planos. Os animais foram mantidos em biotério até o 60º PO, quando, então, realizou-se arteriografia de controle, e análise macro e microscópica de peça. Resultados: Para se atingir a amostra desejada, foram necessários 12 procedimentos no grupo PDMSr e 16 no grupo PTFEe. Ocorreram 2 óbitos no grupo PDMSr e 6 no grupo PTFEe. Apesar do número maior de óbitos no grupo PTFEe não houve diferença estatística na sobrevida entre os grupos. Um animal do grupo PDMSr apresentou monoparesia em pata posterior direita e um animal do grupo PTFEe apresentou hérnia incisional. Não houve diferença estatística nas complicações entre os grupos. O tempo operatório foi estatisticamente maior no grupo PTFEe quando comparamos todos os animais, fato que não se repetiu quando excluímos os animais que faleceram. O peso e o tempo operatório foram estatisticamente maiores nos animais que morreram. Todos os animais que chegaram ao final do tempo de estudo apresentavam aorta patente. Na análise macroscópica da peça, houve, estatisticamente, maior reação tecidual periprótese no grupo PTFEe. A microscopia eletrônica de varredura evidenciou cobertura de todo o remendo de PDMSr por tecido similar ao endotélio, enquanto, nos remendos de PTFEe, o crescimento limitou-se às bordas da linha de sutura e ilhas isoladas no seu centro. Conclusão: O material estudado apresentou resultados comparáveis ao do PTFEe, porém com menor reação tecidual local e maior proliferação celular para a luz do vaso. Apesar de novos estudos serem necessários, inclusive para avaliação de uso em humanos, o presente estudo apresenta resultados promissores que encorajam a continuidade de sua pesquisa / Introduction: Although good results are reported for various materials for use as patches for arterial closure, as yet none of these is ideal. Therefore, research is continuing into development of a patch that is biocompatible and provides ease of handling, while having satisfactory outcomes. A new silicone arterial patch (polydimethylsiloxane reinforced with polyester fabric, PDMSr) was compared with patches made of expanded polytetrafluoroethylene (ePTFE). Objective: To compare the outcomes between arterial patches made of PDMSr with those made of ePTFE, in an experimental rabbit model. Materials and Method: Rabbits were placed in two groups, and received either PDMSr or ePTFE arterial patches (PDMSr group and ePTFE group, respectively). The animals underwent laparotomy and longitudinal opening of the aorta, which was then closed with the selected patch, followed by suture of all layers. The animals were kept in their cages until the 60th postoperative day, when arteriography, removal of the aorta, and macroscopic and optic and scanning electron microscopic analyzes of the aorta were performed. Ten rabbits from each group that had completed all stages of the research were included in analyses. Results: Twelve procedures were performed in the PDMSr group and 16 in the ePTFE group. There were 2 deaths in the PDMSr group and 6 in the ePTFE group. Despite the higher number of deaths in the ePTFE group, there was no statistical difference in survival rate between the groups. One animal in the PDMSr group developed monoparesis in its right hind paw and 1 animal in the ePTFE group had an incisional hernia. There was no statistical difference in complications between the groups. The operative time was significantly longer in the ePTFE group when all animals were included in analysis, but not when animals that died were excluded. Body weight was significantly greater and operative time was significantly longer in animals that died. Postsurgical aortic patency in the survival animals was 100% in both groups by arteriography. Macroscopically, tissue reaction around the prosthesis was greater in the ePTFE group (statistically significant). Microscopically, the PDMSr patches were entirely covered with a cellular endothelium-like tissue, while tissue growth on the ePTFE patches was limited to the edges of the suture line and to isolated central islands. Conclusion: The two materials showed comparable outcomes; however, PDMSr showed cellular proliferation to the entire graft, and less local inflammatory reaction compared with ePTFE. Although further studies are required, including assessment in humans, the results of the present study indicate that PDMSr shows promise as an arterial patch material

Em um estudo prospectivo sobre o tratamento das artroplastias de quadril infectadas, com perdas ósseas e fístulas ativas, 25 pacientes foram tratados em dois tempos e 36 pacientes foram tratados em dois tempos com espaçador de cimento impregnado com vancomicina. O acompanhamento médio foi de dois anos e onze meses. A taxa de recidiva infecciosa foi de 29,2% nos tratados em dois tempos e de 8,8% nos tratados com espaçador. O Escore de Harris para Quadril médio passou de 19,3 para 69,0 pontos nos casos tratados em dois tempos e de 19,7 para 72,2 pontos nos pacientes tratados com espaçador. Ao final do estudo, 86,1% dos tratados com espaçador e em 33,3% dos tratados em dois tempos tinham próteses em bom funcionamento e sem infecção. O espaçador de cimento com antibiótico é o tratamento de escolha nas próteses infectadas de quadril / We report a prospective study of 61 patients with chronically deep infected hip replacements with actively discharging sinuses, treated with a two-stage revision protocol, with and without a cement spacer impregnated with vancomycin. The average follow-up was two years and eleven months. Twenty-five patients were treated without a spacer and seven had recurrence of infection. Thirty-three patients were treated with a spacer and three had recurrence of infection. The average Harris Hip score increased from 19,3 to 69,0 on the non-spacer patients and from 19,7 to 75,2 on the spacer group. At the end of the study, the success rate was 86,1% for the spacer group and 33,3% for the non-spacer group. The use of the spacer increased the results of the two-stage chronic infected hip replacements

Made available in DSpace on 2014-12-17T15:42:01Z (GMT). No. of bitstreams: 1 IedaNSM.pdf: 5948604 bytes, checksum: dbf245a349dd04cff535e8ba2e89601d (MD5) Previous issue date: 2007-07-06 / The aim of this work was to study a series of 11 different compositions of Ti-Zr binary alloys resistance to aggressive environment, i. e., their ability to keep their surface properties and mass when exposed to them as a way to evaluate their performance as biomaterials. The first stage was devoted to the fabrication of tablets from these alloys by Plasma-Skull casting method using a Discovery Plasma machine from EDG Equipamentos, Brazil. In a second stage, the chemical composition of each produced tablet was verified. In a third stage, the specimen were submitted to: as-cast microstructure analysis via optical and scanning electron microscopy (OM and SEM), x-ray dispersive system (EDS) chemical analysis via SEM, Vickers hardness tests for mechanical evaluation and corrosion resistence tests in a 0.9% NaCl solution to simulate exposition to human saliva monitored by open circuit potential and polarization curves. From the obtained results, it was possible to infer that specimens A1 (94,07 wt% Ti and 5,93% wt% Zr), A4 (77,81 wt % Ti and 22,19 wt % Zr) and A8 (27,83 wt% Ti and 72,17 wt% Zr), presented best performance regarding to corrosion resistance, homogeneity and hardness which are necessary issues for biomaterials to be applied as orthopedic and odontological prosthesis / Este trabalho teve como finalidade estudar uma s?rie de onze ligas met?licas bin?rias, tit?nio zirc?nio, quanto ? capacidade de resistirem ?s deteriora??es sem sofrerem modifica??es de suas propriedades iniciais de massa e superf?cie quando expostas a meios agressivos, como condi??o fundamental para que as mesmas sejam aplicadas como biomateriais. A primeira etapa tratou da confec??o das amostras das ligas em forma de pastilhas, empregando-se o processo de fundi??o Plasma Skull realizado na m?quina Discovery Plasma, produzida no Brasil pela EDG Equipamentos. Na segunda etapa, as amostras confeccionadas foram submetidas aos ensaios para a determina??o da composi??o qu?mica resultante de cada liga da s?rie ap?s a fus?o. E durante a terceira etapa foram feitos os procedimentos de avalia??es das amostras quanto ? homogeneidade e apresenta??o da microestrutura de cada uma das ligas no estado bruto de fus?o, como resultados dos ensaios metalogr?ficos por microscopia ?ptica e microscopia eletr?nica de varredura acoplada a espectroscopia por energia dispersiva de raios-x; quanto ? propriedade mec?nica de dureza medida em escala Vickers (HV); e quanto ?s propriedades qu?micas de resist?ncia ? corros?o, quando expostas em solu??o de cloreto de s?dio 0,9 %, para simular a saliva, empregando-se o monitoramento do potencial de circuito aberto e as curvas de polariza??o. A partir dos resultados obtidos foi poss?vel identificar as pastilhas de composi??es qu?micas A1 (94,07% de Ti e 5,93% de Zr), A4 (77,81% de Ti e 22,19% de Zr) e A8 (27,83% de Ti e 72,17% de Zr) que resultaram como maiores detentoras do conjunto de propriedades de resist?ncia ? corros?o, homogeneidade e dureza, as quais s?o mais necess?rias em biomateriais tipo pr?teses ortop?dicas ou odontol?gicas