A system for vessel characterization aimed at detecting deep vein thrombosis (DVT) in the lower limbs has been developed and evaluated using ultrasound image processing, location and force sensors measurements, blood flow information and a protocol based on the current clinical standard, compression ultrasound. The goal is to provide an objective and repeatable system to measure DVT in a rapid and standardized manner, as this has been suggested in the literature as an approach to improve overall detection of the disease. The system uses a spatial Kalman filter-based algorithm with an elliptical model in the measurement equation to detect vessel contours in transverse ultrasound images and estimate ellipse parameters, and temporal constant velocity Kalman filters for tracking vessel location in real-time. The vessel characterization also comprises building a 3-D vessel model and performing compression and blood flow assessments to calculate measures that indicate the possibility of DVT in a vessel. A user interface designed for assessing a vessel for DVT was also developed. The system and components were implemented and tested in simulations, laboratory settings, and clinical settings. Contour detection results are good, with mean and rms errors ranging from 1.47-3.64 and 3.69-9.67 pixels, respectively, in simulated and patient images, and parameter estimation errors of 5%. Experiments showed errors of 3-5 pixels for the tracking approaches. The measures for DVT were evaluated, independently and integrated in the system. The complete system was evaluated, with sensitivity of 67-100% and specificity of 50-89.5%. System learnability and memorability were evaluated in a separate user study, with good results. Contributions include a segmentation approach using a full parameter ellipse model in an extended Kalman filter, incorporating multiple measurements, an alternate sampling method for faster parameter convergence and application-specific initialization, and a tracking approach that includes a sub-sampled sum of absolutes similarity calculation and a method to detect vessel bifurcations using flow data. Further contributions include an integrated system for DVT detection that can combine ultrasound B-mode, colour flow and elastography images for vessel characterization, a system interface design focusing on usability that was evaluated with medical professionals, and system evaluations through multiple patient studies.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 6 uppsatser.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2007. / Committee Chair: David N. Ku; Committee Member: Cyrus Aidun; Committee Member: Don P. Giddens.

Thesis (MSc.(Anatomy)--Faculty of Health Sciences)-University of Pretoria, 2008. / Includes bibliographical references.

L'objectif de notre première étude était d'identifier les déterminants génétiques et environnementaux du risque de maladie thromboembolique veineuse (MTEV) chez les femmes sous contraceptifs oraux combinés (COC). Après ajustement pour les facteurs confondants, les principaux déterminants environnementaux de la MTEV étaient le tabagisme (OR = 1,65) et un indice de masse corporelle supérieur à 35 kg.m2 (OR = 3,46). En outre, la thrombophilie héréditaire sévère (OR = 2,13) et les groupes sanguins non-O (OR = 1,98). Nous avons confirmé que l’histoire familiale au premier degré de MTEV prédit mal la thrombophilie. En conclusion, cette étude confirme l'influence du tabagisme et de l'obésité et pour la première fois l'impact du groupe sanguin ABO sur le risque de MTEV chez les femmes sous COC. Elle confirme également la faible sensibilité de l'histoire familiale de MTEV pour dépister les thrombophilies héréditaires.Le but de la deuxième étude était d'étudier, chez les utilisatrices de COC, l'impact des polymorphismes génétiques nouvellement identifiés par les études pangénomiques associés au risque de MTEV dans la population générale. Neuf polymorphismes situés sur les gènes KNG1, F11, F5, F2, PROCR, FGG, TSPAN15 et SLC44A2 ont été génotypés dans un échantillon de 766 cas et 464 témoins dans le cadre de l’étude PILGRIM. Seul le polymorphisme rs2289252 situé sur le F11 était significativement associé au risque de MTEV. La présence de l’allèle rs2289252-A du F11 était associée à un risque accru de MTEV (OR =1,6). En outre, la combinaison de l’allèle rs2289252-A et du groupe sanguin non-O, était associée à un risque d’OR de 4. / The aim of our first study was to identify the genetic and environmental determinants of venous thromboembolism (VTE) risk in a large sample of women using combined oral contraceptives (COC). A total of 968 women with a personal history of VTE during COC use were compared with 874 women under COC, but no personal history of VTE. After adjustment for confounding factors, the main environmental determinants of VTE were smoking odds ratio (OR = 1.65) and a body mass index greater than 35 kg.m-2 (OR = 3.46). In addition, severe hereditary thrombophilia (OR = 2.13) and non-O blood groups (OR = 1.98) have been shown to be important genetic risk factors for VTE under COC. First-degree family history of VTE predicts thrombophilia poorly. In conclusion, this study confirms the influence of smoking and obesity and for the first time the impact of ABO blood group on the risk of VTE in women under COC It also confirms the low sensitivity of the family history of VTE to detect hereditary thrombophilia. The purpose of the second study was to study, in COC users, the impact of newly identified genetic polymorphisms by genome-wide as associated with the risk of VTE in the general population. Nine polymorphisms on the KNG1, F11, F5, F2, PROCR, FGG, TSPAN15 and SLC44A2 genes were genotyped in a sample of 766 patients and 464 controls in the PILGRIM study. Only the rs2289252 polymorphism on the F11 was significantly associated with the risk of VTE. The presence of the F11 rs2289252-A allele was associated with an increased risk of VTE (OR = 1.6). In addition, the combination of the rs2289252-A allele and the non-O blood group was associated with an OR risk of 4.

Made available in DSpace on 2014-06-11T19:32:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-11-14Bitstream added on 2014-06-13T21:04:42Z : No. of bitstreams: 1 tofano_vac_dr_botfm.pdf: 984641 bytes, checksum: d4fcddf13acc4d52c783e4c30966c9b0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A trombose venosa profunda (TVP) caracteriza-se pela formação aguda de um trombo no interior das veias profundas. É uma doença de alta incidência e de grande importância clínica e epidemiológica devido à sua morbimortalidade, sendo atualmente, considerada multifatorial. São vários os fatores de risco genéticos e/ou adquiridos relacionados à TVP e a compreensão da interação destes, permite melhor entender esta doença, não só devido aos seus sintomas de fase aguda mas, principalmente, por sua complicação mais temida, a embolia pulmonar e, a longo prazo, a síndrome pós-trombótica (SPT), que apresenta importante morbidade, inclusive com repercussões sócio-econômicas. A avaliação a longo prazo, clínica e ultrassonográfica, de pacientes com diagnóstico de TVP, visando verificar a incidência e gravidade da SPT é necessária para a compreensão da evolução destes pacientes. Desconhecemos a existência de trabalhos em nosso meio, que avaliem a evolução tardia da TVP. Objetivo: Determinar a evolução a longo prazo de pacientes com TVP de membros, portadores de trombofilia e verificar se existem diferenças na evolução de pacientes trombofílicos e não trombofílicos. Método: Num estudo coorte retrospectivo foram avaliados os prontuários de 275 pacientes atendidos no Hospital das Clínicas da Faculdade de Medicina de Botucatu-Unesp, dos quais foram identificados 60 pacientes trombofílicos, sendo possível contactar 40 deles para consulta, dos quais 39 pacientes aceitaram participar do estudo. Foram selecionados 25 pacientes com diagnóstico de TVP, não trombofílicos, pareados para sexo e idade, para comparação com o grupo trombofílico. Durante a consulta foi preenchido um protocolo que continha as seguintes variáveis: dados demográficos, profissão, antecedentes pessoais e antecedentes obstétricos (se mulher), antecedentes familiares com relação... / Deep vein thrombosis (DVT) is characterized by the acute formation of a thrombus in the interior of the deep veins. It is a disease of high incidence and great clinical and epidemiological importance due to its morbimortality, being presently considered multifactorial. The genetic and/or acquired risk factors related to DVT are various and understanding their interaction allows a better comprehension of this illness, due to both symptoms of the acute stage and, mainly, its most feared complication, the pulmonary embolism and, in long term, the post-thrombotic syndrome (PTS), which presents important morbidity, inclusively with social and economical repercussions. The long-term clinical and ultrasound evaluation of patients with DVT diagnosis, aiming to verify the incidence and seriousness of PTS, is necessary to understand the evolution of these patients. We are not aware of the existence of works in our area which evaluate the late evolution of DVT. Objective: To determine the long-term evolution of patients with DVT of limbs, carriers of thrombophilia, and verify the existence of differences in the evolution of thrombophilic and non-thrombophilic patients. Method: In a retrospective cohort study, the medical registers of 275 patients attended at the Clinics Hospital of the School of Medicine of the Paulista State University, in Botucatu, São Paulo, Brazil, were evaluated, from which 60 thrombophilic patients were identified. It was possible to contact 40 of them for appointment, from which 39 patients accepted to participate in the study. 25 non-thrombophilic patients, paired for sex and age, were selected with DVT diagnosis, for comparison with the thrombophilic group. During the appointment, a protocol was filled in, containing the following variables: demographic data, occupation, personal antecedents and obstetric antecedents (if woman), familiar antecedents concerning thrombosis... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:35:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-19Bitstream added on 2014-06-13T21:07:34Z : No. of bitstreams: 1 machado_abc_dr_botfm.pdf: 2908111 bytes, checksum: 943cbe30c7037e83e7c7884f353a992a (MD5) / Not available

Made available in DSpace on 2016-07-01T13:10:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-30. Added 1 bitstream(s) on 2016-07-01T13:14:19Z : No. of bitstreams: 1 000866836.pdf: 2053587 bytes, checksum: 2f5cfc3b1ae4c8dc9398d66ec7878478 (MD5) / Espera-se que trombose do enxerto renal ocorra em 1-6% dos transplantes de rim, e que a perda definitiva do enxerto geralmente decorra desse evento. Anticoagulantes e antiagregantes plaquetários poderiam servir como medidas farmacológicas para prevení-la, mas evidências de alta qualidade para seus benefícios até o momento inexistem. Desta forma, avaliamos a efetividade e segurança destes agentes na redução da taxa de trombose do enxerto renal, através da análise de dados obtidos a partir de estudos de séries de casos. Métodos: Foi realizada uma revisão de literatura, nas principais bases de dados eletrônicas da área da saúde (MEDLINE, EMBASE e LILACS), para identificar todos os estudos de séries de casos disponíveis sobre o uso de anticoagulantes e/ou antiplaquetários na prevenção trombose do enxerto, no transplante renal. Os dados sobre os eventos de interesse foram agrupados e analisados em uma meta-análise proporcional. A presença de significância estatística nas comparações foi estabelecida quando os intervalos de confiança de 95% (IC 95%) obtidos para cada intervenção testada não apresentassem sobreposição. Resultados: 21 séries de casos foram incluídas, a partir de 7.160 títulos identificados inicialmente nas bases de dados. Um total de 3.246 pacientes foram analisados (1.718 tratados com antiplaquetários e/ou agentes anticoagulantes e 1.528 indivíduos não tratados, como controle). Trombose do aloenxerto ocorreu em 7,24% (IC 95% 3,45 - 12,27%) dos pacientes que receberam nenhuma intervenção, em comparação com 3,38% (IC 95% 1,45 - 6,08%) dos que usaram apenas anticoagulantes, 1,20% (IC 95% 0,60 - 2,10%) daqueles em uso apenas de aspirina e 0,47% (IC 95% 0,001 - 1,79%) dos que receberam aspirina + anticoagulantes. Houve assim diferença estatisticamente significante, mostrando uma redução na ocorrência de trombose, somente nos pacientes que receberam... / It is expected that renal graft thrombosis occurs in 1-6% of kidney transplants, and that graft loss usually arises from that event. Anticoagulants and antiplatelet agents could serve as pharmacological measures to prevent it, but high-quality evidence for its benefits are lacking at this moment. Thus, we evaluated the efficacy and safety of these agents in reducing the rate of thrombosis in renal grafts through analysis of data obtained from case series studies. Methods: A literature review was conducted, in the main electronic health-related databases (MEDLINE, EMBASE and LILACS), to identify all available case series studies on the use of anticoagulants and/or antiplatelet agents in preventing graft thrombosis in renal transplantation. Data on events of interest were pooled and analyzed on a proportional meta-analysis. The presence of statistical significance in the comparisons was established when the 95% confidence intervals (95% CI) obtained for each tested intervention did not present overlapping. Results: 21 case series were included, from 7,160 titles originally identified in the databases. A total of 3,246 patients were analyzed (1,718 treated with antiplatelet and/or anticoagulant agents and 1,528 individuals as untreated controls). Allograft thrombosis occurred in 7.24% (95% CI 3.45 to 12.27%) of patients that received no intervention, compared with 3.38% (95% CI 1.45 to 6.08%) of who used only anticoagulant, 1.20% (95% CI 0.60 to 2.10%) of those in use only of aspirin and 0.47% (95% CI 0.001 to 1.79%) of those who received aspirin + anticoagulants. As such, there was a statistically significant difference showing a reduction in the occurrence of thrombosis, only in patients receiving aspirin or aspirin + anticoagulants, compared to untreated controls. The rate of complications related to bleeding was statistically higher with use of anticoagulants (28.00%; 95% CI 15.40 to 42.70%)...

Orientador: José Eduardo Corrente / Banca: Paulo José Fortes Villas Boas / Banca: Francisco Humberto de Abreu Maffei / Banca: Marcelo M. Pinheiro / Banca: Luiz Eugênio G. Leme / Resumo: Não disponível / Abstract: Not available / Doutor

Orientador: Regina Paolucci El Dib / Coorientador: Paulo Roberto Kawano / Coorientador: João Luiz Amaro / Banca: Pasqual Barretti / Banca: Luís Gustavo Modelli de Andrade / Banca: Sílvio Tucci Júnior / Banca: Eduardo Hidetoshi Fugita / Resumo: Espera-se que trombose do enxerto renal ocorra em 1-6% dos transplantes de rim, e que a perda definitiva do enxerto geralmente decorra desse evento. Anticoagulantes e antiagregantes plaquetários poderiam servir como medidas farmacológicas para prevení-la, mas evidências de alta qualidade para seus benefícios até o momento inexistem. Desta forma, avaliamos a efetividade e segurança destes agentes na redução da taxa de trombose do enxerto renal, através da análise de dados obtidos a partir de estudos de séries de casos. Métodos: Foi realizada uma revisão de literatura, nas principais bases de dados eletrônicas da área da saúde (MEDLINE, EMBASE e LILACS), para identificar todos os estudos de séries de casos disponíveis sobre o uso de anticoagulantes e/ou antiplaquetários na prevenção trombose do enxerto, no transplante renal. Os dados sobre os eventos de interesse foram agrupados e analisados em uma meta-análise proporcional. A presença de significância estatística nas comparações foi estabelecida quando os intervalos de confiança de 95% (IC 95%) obtidos para cada intervenção testada não apresentassem sobreposição. Resultados: 21 séries de casos foram incluídas, a partir de 7.160 títulos identificados inicialmente nas bases de dados. Um total de 3.246 pacientes foram analisados (1.718 tratados com antiplaquetários e/ou agentes anticoagulantes e 1.528 indivíduos não tratados, como controle). Trombose do aloenxerto ocorreu em 7,24% (IC 95% 3,45 - 12,27%) dos pacientes que receberam nenhuma intervenção, em comparação com 3,38% (IC 95% 1,45 - 6,08%) dos que usaram apenas anticoagulantes, 1,20% (IC 95% 0,60 - 2,10%) daqueles em uso apenas de aspirina e 0,47% (IC 95% 0,001 - 1,79%) dos que receberam aspirina + anticoagulantes. Houve assim diferença estatisticamente significante, mostrando uma redução na ocorrência de trombose, somente nos pacientes que receberam... / Abstract: It is expected that renal graft thrombosis occurs in 1-6% of kidney transplants, and that graft loss usually arises from that event. Anticoagulants and antiplatelet agents could serve as pharmacological measures to prevent it, but high-quality evidence for its benefits are lacking at this moment. Thus, we evaluated the efficacy and safety of these agents in reducing the rate of thrombosis in renal grafts through analysis of data obtained from case series studies. Methods: A literature review was conducted, in the main electronic health-related databases (MEDLINE, EMBASE and LILACS), to identify all available case series studies on the use of anticoagulants and/or antiplatelet agents in preventing graft thrombosis in renal transplantation. Data on events of interest were pooled and analyzed on a proportional meta-analysis. The presence of statistical significance in the comparisons was established when the 95% confidence intervals (95% CI) obtained for each tested intervention did not present overlapping. Results: 21 case series were included, from 7,160 titles originally identified in the databases. A total of 3,246 patients were analyzed (1,718 treated with antiplatelet and/or anticoagulant agents and 1,528 individuals as untreated controls). Allograft thrombosis occurred in 7.24% (95% CI 3.45 to 12.27%) of patients that received no intervention, compared with 3.38% (95% CI 1.45 to 6.08%) of who used only anticoagulant, 1.20% (95% CI 0.60 to 2.10%) of those in use only of aspirin and 0.47% (95% CI 0.001 to 1.79%) of those who received aspirin + anticoagulants. As such, there was a statistically significant difference showing a reduction in the occurrence of thrombosis, only in patients receiving aspirin or aspirin + anticoagulants, compared to untreated controls. The rate of complications related to bleeding was statistically higher with use of anticoagulants (28.00%; 95% CI 15.40 to 42.70%)... / Doutor