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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Contribuição para informatização de programas de proteção radiológica para instalações radiativas / Contribution to the informatization of radiation protection programs for nuclear facilities other than nuclear fuel cycle

Denise Sahyun Levy 01 October 2012 (has links)
Para elaborar um programa de proteção radiológica, as instalações radiativas brasileiras devem considerar normas, diretrizes e recomendações nacionais e internacionais que encontram-se em documentos de diferentes organizações publicados nas últimas décadas: Comissão Internacional de Proteção Radiológica (CIPR), Organismo Internacional de Energia Atômica (OIEA) e Comissão Nacional de Energia Nuclear (CNEN). Visando a proporcionar a essas instalações o acesso às informações pertinentes de forma rápida, integrada e eficiente, este projeto propõe informatizar e disponibilizar em um só documento os programas de otimização da proteção radiológica unificados, inter-relacionados e em português, fornecendo ao público usuário um veículo completo para fins de pesquisa, consulta e informação. A partir do discernimento do que deve conter cada programa e seu real dimensionamento, foi trabalhado o inter-relacionamento das informações de maneira a satisfazer as normas e recomendações nacionais e internacionais. O projeto inclui conceitos, definições e teoria necessários, além da pesquisa detalhada do conteúdo do programa de otimização, das técnicas de ajuda para tomada de decisão, das doses de radiação e detrimento e das informações relacionadas aos custos de proteção. O conteúdo permite responder a todas as questões que devem ser colocadas na elaboração de um programa de otimização de forma a possibilitar montagem do plano de Proteção Radiológica conforme a situação específica do usuário. Para a informatização dos programas de otimização foram estudadas as possibilidades de acesso à Tecnologia da Informação e Comunicação nas empresas brasileiras, possibilitando identificar o perfil de utilização do sistema e definir a estrutura funcional adequada para a criação das melhores interfaces de ferramentas e recursos, bem como de um projeto de navegabilidade eficaz facilitando a busca de informações. O poder de processamento dos servidores aliado à tecnologia dos bancos de dados relacionais permite correlacionar informações advindas de diferentes fontes, possibilitando consultas complexas com tempo de resposta reduzido. O sistema segue o padrão WEB 2.0, que possibilita a estrutura organizacional necessária para a adequada informatização da proteção radiológica e considera os corretos critérios de indexação da informação para garantir seu reconhecimento pelos motores de busca da internet. O projeto conta com a combinação de várias tecnologias, potencializando os recursos disponíveis em cada uma delas para alcançar os objetivos propostos. Este trabalho experimental lança um cerne inicial para a informatização dos programas de proteção radiológica, informatizando inicialmente os programas de otimização. A investigação do perfil de utilização durante um período de cinco meses possibilitou o levantamento de dados importantes que apontam novas possibilidades para o desenvolvimento da informatização dos programas de proteção radiológica. Pretende-se, a partir dos resultados deste projeto, aprofundar o trabalho de investigação e completar a execução do sistema de informatização. / In order to establish a Radiation Protection Plan or a Radiation Emergency Plan, Brazilian facilities should take into account all procedures based on both national and international standards, guidelines and recommendations. This information can be found in several documents published by different organizations over the past decades, namely: the International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA) and Comissão Nacional de Energia Nuclear (CNEN). This project aims the informatization of the radiological protection optimization programs in a single system in order to offer unified programs and inter-related information in Portuguese, providing Brazilian radioactive facilities a complete repository for research, consultation and information. In order to meet both national and international recommendations within the scope of this work, we conducted a comprehensive job of perception about each program contents as well as its real dimension, identifying and detailing the vital parts of programs. The content includes concepts, definitions and theory in addition to the optimization programs, help decision making techniques, information related to protection costs, radiation doses and detriment. The content allows to answer to every question when an optimization program is elaborated, according to decision maker´s specific situation. For dimensioning the work of informatization and developing the WEB platform according to the needs of the target public profile, we have conducted an extensive research regarding the possibilities of Information and Communication Technology access in companies throughout the country. That allowed us to define the best interfaces tools and resources. The servers processing power added to the technology of relational databases allow to integrate information from different sources, enabling complex queries with reduced response time. The project was implemented in a web environment, using the Web 2.0 tools and resources that allow the entire organizational structure, that would enable the inter-relationships and joints needed for proper use of information technology in radiological protection. The correct indexing of contents guarantees that search engines will find the desired information in the shortest time possible. This project uses the combination of multiple technologies, maximizing the resources available in each one of them in order to achieve our goals. For now we intend to begin an initial core working only the optimization program, which in the near future could be extended to other fields of radiological protection. The investigation of the usage profile for five months enabled important data that suggest new possibilities for the development of computerization of radiation protection programs. According to the results of this project, we intend to lead a further research work and complete the informatization system.
62

Contribuição para informatização de programas de proteção radiológica para instalações radiativas / Contribution to the informatization of radiation protection programs for nuclear facilities other than nuclear fuel cycle

Levy, Denise Sahyun 01 October 2012 (has links)
Para elaborar um programa de proteção radiológica, as instalações radiativas brasileiras devem considerar normas, diretrizes e recomendações nacionais e internacionais que encontram-se em documentos de diferentes organizações publicados nas últimas décadas: Comissão Internacional de Proteção Radiológica (CIPR), Organismo Internacional de Energia Atômica (OIEA) e Comissão Nacional de Energia Nuclear (CNEN). Visando a proporcionar a essas instalações o acesso às informações pertinentes de forma rápida, integrada e eficiente, este projeto propõe informatizar e disponibilizar em um só documento os programas de otimização da proteção radiológica unificados, inter-relacionados e em português, fornecendo ao público usuário um veículo completo para fins de pesquisa, consulta e informação. A partir do discernimento do que deve conter cada programa e seu real dimensionamento, foi trabalhado o inter-relacionamento das informações de maneira a satisfazer as normas e recomendações nacionais e internacionais. O projeto inclui conceitos, definições e teoria necessários, além da pesquisa detalhada do conteúdo do programa de otimização, das técnicas de ajuda para tomada de decisão, das doses de radiação e detrimento e das informações relacionadas aos custos de proteção. O conteúdo permite responder a todas as questões que devem ser colocadas na elaboração de um programa de otimização de forma a possibilitar montagem do plano de Proteção Radiológica conforme a situação específica do usuário. Para a informatização dos programas de otimização foram estudadas as possibilidades de acesso à Tecnologia da Informação e Comunicação nas empresas brasileiras, possibilitando identificar o perfil de utilização do sistema e definir a estrutura funcional adequada para a criação das melhores interfaces de ferramentas e recursos, bem como de um projeto de navegabilidade eficaz facilitando a busca de informações. O poder de processamento dos servidores aliado à tecnologia dos bancos de dados relacionais permite correlacionar informações advindas de diferentes fontes, possibilitando consultas complexas com tempo de resposta reduzido. O sistema segue o padrão WEB 2.0, que possibilita a estrutura organizacional necessária para a adequada informatização da proteção radiológica e considera os corretos critérios de indexação da informação para garantir seu reconhecimento pelos motores de busca da internet. O projeto conta com a combinação de várias tecnologias, potencializando os recursos disponíveis em cada uma delas para alcançar os objetivos propostos. Este trabalho experimental lança um cerne inicial para a informatização dos programas de proteção radiológica, informatizando inicialmente os programas de otimização. A investigação do perfil de utilização durante um período de cinco meses possibilitou o levantamento de dados importantes que apontam novas possibilidades para o desenvolvimento da informatização dos programas de proteção radiológica. Pretende-se, a partir dos resultados deste projeto, aprofundar o trabalho de investigação e completar a execução do sistema de informatização. / In order to establish a Radiation Protection Plan or a Radiation Emergency Plan, Brazilian facilities should take into account all procedures based on both national and international standards, guidelines and recommendations. This information can be found in several documents published by different organizations over the past decades, namely: the International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA) and Comissão Nacional de Energia Nuclear (CNEN). This project aims the informatization of the radiological protection optimization programs in a single system in order to offer unified programs and inter-related information in Portuguese, providing Brazilian radioactive facilities a complete repository for research, consultation and information. In order to meet both national and international recommendations within the scope of this work, we conducted a comprehensive job of perception about each program contents as well as its real dimension, identifying and detailing the vital parts of programs. The content includes concepts, definitions and theory in addition to the optimization programs, help decision making techniques, information related to protection costs, radiation doses and detriment. The content allows to answer to every question when an optimization program is elaborated, according to decision maker´s specific situation. For dimensioning the work of informatization and developing the WEB platform according to the needs of the target public profile, we have conducted an extensive research regarding the possibilities of Information and Communication Technology access in companies throughout the country. That allowed us to define the best interfaces tools and resources. The servers processing power added to the technology of relational databases allow to integrate information from different sources, enabling complex queries with reduced response time. The project was implemented in a web environment, using the Web 2.0 tools and resources that allow the entire organizational structure, that would enable the inter-relationships and joints needed for proper use of information technology in radiological protection. The correct indexing of contents guarantees that search engines will find the desired information in the shortest time possible. This project uses the combination of multiple technologies, maximizing the resources available in each one of them in order to achieve our goals. For now we intend to begin an initial core working only the optimization program, which in the near future could be extended to other fields of radiological protection. The investigation of the usage profile for five months enabled important data that suggest new possibilities for the development of computerization of radiation protection programs. According to the results of this project, we intend to lead a further research work and complete the informatization system.
63

Distal Radius Fractures : aspects on radiological and clinical outcome and evaluation of a new classification system

Wadsten, Mats January 2016 (has links)
Distal radius fracture (DRF) is the most common fracture encountered in clinical practice. Every year, more than 20000 people in Sweden suffer from this injury. It has been shown that there is a correlation between malalignment and function following distal radial fractures and malunion may cause persistent pain and disability. A problem has been in making a correct initial assessment of the fracture. Many fractures are unstable despite an acceptable position on the initial radiographic examination or following a successful closed fracture reduction. Numerous classification systems have been developed for evaluation of DRF in order to predict the outcome. However, the values of these are limited since they have not shown satisfactory reliability. Furthermore, the utility of these systems to predict radiographic or clinical outcome is not yet proven. These shortcomings may be one reason why optimal DRF management is still controversial. Requests for a new classification system of DRF, predictive of outcome and easy to use, have been made. Improvement in initial assessment of DRF will benefit a large group of patients, as well as the society, by reducing persistent symptoms and disability. Study I: In this study we evaluated the interobserver and intraobserver reliability of a new classification system (the Buttazzoni classification). Two hundred and thirty-two patients with acute DRF were blindly evaluated using the new classification by three orthopaedic surgeons twice with a 1-year interval. The new classification showed fair to substantial interobserver and intraobserver reliability, i.e., results comparable with other commonly used classification systems. Study II: This was a prospective multicenter study of fracture stability in 428 DRF. The study investigated whether cortical comminution and intra-articular involvement, as well as the new classification system, could predict displacement in DRF. Logistic regression analysis showed that initial position of the fracture and volar or dorsal comminution predicted later displacement, while intra-articular involvement did not. Volar comminution was the strongest predictor of displacement. The new classification system, which is the first to include volar comminution as a separate parameter, was highly predictive of fracture instability. Furthermore we found that it is quite common for non-operatively treated fractures to displace at a later stage than two weeks. Study IV: In study II it was found that late displacement of DRF, still in acceptable radiologic position after 10-14 days, occurred in approximately 1/3 of cases. Despite this, we have not been able to find any study focusing on evaluating the clinical outcome in patients with late displacement. Two hundred and nine unilateral DRF from study II were still in good position after 10-14 days and were included in the study. One hundred and seventy five patients had radiographs taken at a minimum of 3 months and a clinical examination 1 year after the fracture. Late displaced distal radius fractures had significantly higher loss of ROM and grip strength compared to fractures that didn’t displace. No significant differences were seen in subjective outcome. In conclusion, initial position of the fracture predicted later displacement and was the most important parameter in predicting clinical outcome. Comminution of the fracture also affected radiological stability and clinical outcome. Volar comminuted fractures are highly unstable and need surgical intervention if displacement is to be avoided. Intra-articular involvement affected clinical outcome. Late displacement is common in DRF and may result in loss of range of motion and grip strength. To detect late displacement, DRF should be followed for more than 2 weeks. The new classification system had a moderate reliability and reproducibility. The classification was found predictive of radiologic and objective clinical outcome. However, it was not predictive of subjective outcome. The classification system was also predictive of fractures at risk for late displacement.
64

The association of demographics and occupational factors with latent tuberculosis infection in radiology staff at public sector hospitals in the eThekwini health district

Ackah, Shiroma 03 1900 (has links)
Submitted in fulfillment of the requirements for the degree of Master’s of Technology: Radiography, Durban University of Technology, Durban, South Africa, 2015. / Introduction Tuberculosis remains a leading cause of death, second to the Human Immunodeficiency Virus. The risk of latent tuberculosis infection and active tuberculosis disease is a known occupational hazard. In South Africa, a high tuberculosis burden country, the potential of Mycobacterium tuberculosis transmission to health care workers is high. This includes diagnostic radiographers and other radiology staff working in radiology departments. Purpose of the Study This study aimed to investigate the association of demographic and occupational factors with latent tuberculosis infection in radiology staff in public sector hospitals of the eThekwini Health District. Methodology This cross-sectional study was conducted from 26 February 2013 to 07 June 2013. Quantitative methods were used to test for associations of demographic and occupational factors with latent tuberculosis infection in participants. A sample size of 181 participants for an estimated population of 340 radiology staff was recommended at the proposal stage. The study consisted of two phases; the questionnaire survey (phase one) and the administration of a two-step tuberculin skin test (phase two). Data was obtained with regard to demographics, occupational history, social behaviours, medical history; and family and home histories. Demographic and occupational associations with latent tuberculosis infection were made in relation to the size of the first tuberculin skin test induration. Frequency distributions were developed to describe data categories. Pearson’s and Spearman rho’ correlation coefficients were used to test for correlations between the independent variables. The chi-square test was used to determine associations between the categorical independent variables and the dependent variable. Bivariate analyses were performed using these tests. The multivariate analysis was performed using logistic and linear regression on the dependent variable. Results A total of 182 questionnaires were returned from approximately 280 radiology staff. At the outset, all doctors working in the radiology department had to be excluded due to numerous failed attempts to enlist their participation. Fifty-three (29.12 percent) participants were excluded from phase one of the study and a further thirteen participants were excluded from phase two. The total sample was 116 participants. Of the 116 participants, 86.2 percent tested positive for latent tuberculosis infection at the first step of the two-step testing method used. One (0.86 percent) participant went on to convert at the second step, testing positive at this level. Demographic associations with latent tuberculosis infection included age (older) as an associated factor. A significant demographic association with latent tuberculosis infection was the use of alcohol (p-value 0.033 on the multivariate analysis). Occupational associations with latent tuberculosis infection included longer durations of employment. The annual income (higher income earners) displayed significant associations with latent tuberculosis infection (p-value 0.048 on the multivariate analysis). It is necessary in this study to note that participants include support personnel (lower income earners) making up 37.8 percent of the study, diagnostic radiographers making up 48.3 percent; and radiography managers/assistant managers (highest income earners) making up 13.8 percent of the study. Conclusion and recommendations The risk of transmission of Mycobacterium Tuberculosis to health care workers is a known occupational hazard. This study has described the prevalence of latent tuberculosis infection in radiology staff, at district and regional hospitals within the eThekwini Health District. With 23.62 percent of all participants already having active TB disease and 86.2 percent of the tested group displaying positive results for latent tuberculosis infection, using the tuberculin skin tests, the need for tuberculosis screening is essential. The findings of this study will be used as a health improvement mechanism for stakeholders, having identified potential gaps in medical screening in healthcare in Kwa-Zulu Natal. This study makes recommendations for the early detection of active tuberculosis infection and the monitoring of health care workers that are latently infected, thus assisting in reducing the rate of conversion of latent tuberculosis infection to active tuberculosis disease in radiology staff. This reduces long-term exorbitant costs related to health care associated infections, such as tuberculosis. It also reduces rates of transmission and cross infection to both co-workers and already immunocompromised patients, helping to curb the overall epidemic in South Africa.
65

Den korta mötet i vården : Litteraturstudie med tonvikt på mötet med röntgensjuksköterskan

Jovicic, Senka January 2010 (has links)
<p>Bakgrund: Tidigare forskning visar att röntgensjuksköterskor som gör patienterna delaktiga genom att tillhandahålla information gör det möjligt för patienterna att förstå och själv ta aktiv roll i sin undersökning vilket leder till mindre oro. Med kunskaper och erfarenheter kunde röntgensjuksköterskorna stödja patienterna i samband med undersökningen vilket skapade förtroende och säkerställde trygg atmosfär. Dock kunde sjuksköterskorna även visa brist på känslomässigt engagemang samt bristande förmåga att kommunicera när de var upptagen med praktiska arbetsuppgifter.</p><p>Syfte: Syftet med studien var att beskriva patientens upplevelse av det korta mötet inom vården, med tanken att finna överförbarhet till möte med en röntgensjuksköterska.</p><p>Metod: Litteraturstudie med en kvalitativ ansats och med en kvalitativ innehållsanalys. Studien inkluderade tio vetenskapliga artiklar, som beskriver möten med vården på röntgen, akut- och operationsavdelning.</p><p>Resultat: Resultatet speglar patienternas upplevelser av korta möten, med tonvikten lagd på möten med röntgensjuksköterskor. I resultatet kan referens till källmaterial och dess kontext, såsom röntgen-, akut- och operationsavdelning, utläsas. Dataanalysen resulterade tre huvudkategorier: <em>att bli bekräftad</em>, <em>att uppleva</em> <em>trygghet</em> och <em>att känna</em> <em>maktlöshet</em>. I kategorierna finns totalt sju subkategorier inkluderade. Patienterna kände sig respekterade och bekräftade som individer när sjuksköterskan lyssnade på dem samt tog deras klagomål och önskemål på allvar. Patienterna upplevde trygghet när sjuksköterskan uttryckte intresse och gav dem relevant information. Patienterna upplevde däremot maktlöshet när det var svårt att få kontakt med sjuksköterskan samt göra sina åsikter hörda.</p><p>Slutsats: Studiens resultat visar att patienternas upplevelser av korta möten med röntgensjuksköterskor är allmängiltiga i den bemärkelsen att de kan sägas gälla för verksamheter såsom röntgen-, akut- och operationsavdelning. Dock är det viktigt att poängtera att varje möte med en patient är unikt, vilket innebär att varje patient ska bemötas på ett sätt som skapar förutsättningar för ett välbefinnande.</p>
66

Computer assisted tutoring in radiology

Jeffery, Nathan January 1997 (has links)
No description available.
67

Impact of Tissue Characteristics on Radio-Frequency Lesioning and Navigation in the Brain : Simulation, experimental and clinical studies

Johansson, Johannes January 2009 (has links)
Radio-Frequency (RF) lesioning, or RF ablation, is a method that uses high frequency currents for thermal coagulation of pathological tissue or signal pathways. The current is delivered from an electrode, which also contains a temperature sensor permitting control of the current at a desired target temperature. In the brain, RF lesioning can e.g. be used for treatment of severe chronic pain and movement disorders such as Parkinson’s disease. This thesis focuses on modelling and simulation with the aim of gaining better understanding and predictability of the lesioning process in the central brain.   The finite element method (FEM), together with experimental comparisons, was used to study the effects of electric and thermal conductivity, blood perfusion (Paper I), and cerebrospinal fluid (CSF) filled cysts (Paper II) on resulting lesion volume and shape in brain tissue. The influence of blood perfusion was modelled as an increase in thermal conductivity in non-coagulated tissue. This model gave smaller simulated lesions with increasing blood perfusion as heat was more efficiently conducted from the rim of the lesion. If the coagulation was not taken into consideration, the lesion became larger with increasing thermal conductivity instead, as the increase in conducted heat was compensated for through an increased power output in order to maintain the target temperature. Simulated lesions corresponded well to experimental in-vivo lesions. The electric conductivity in a homogeneous surrounding had little impact but this was not true for a heterogeneous surrounding. CSF has a much higher electric conductivity than brain tissue, which focused the current to the cyst if the electrode tip was in contact with both a cyst and brain tissue. Heating of CSF could also cause considerable convective flow and as a result a very efficient heat transfer. This affected both simulated and experimental lesion sizes and shapes. As a result both very large and very small lesions could be obtained depending on whether sufficient power was supplied or if the heating was mitigated over a large volume.   Clinical (Paper IV) and experimental (Paper III) measurements were used for investigation of changes in reflected light intensity from undamaged and coagulating brain tissue respectively. Monte Carlo (MC) simulations for light transport were made for comparison (Paper V). For the optical measurements, an RF electrode with adjacent optical fibres was used and this electrode was also modelled for the optical simulations. According to the MC simulations, coagulation should make grey matter lighter and white matter darker, while thalamic light grey should remain approximately the same. Experiments in ex-vivo porcine tissue gave an increase in reflected light intensity from grey matter at approximately 50 °C but the signal was very variable and the isotherm 60 °C gave better agreement between simulated and experimental lesions. No consistent decrease in reflected light intensity could be seen during coagulation of white matter. Clinical measurements were performed during the creation of 21 trajectories for deep brain stimulation electrodes. In agreement with the simulations, reflected light intensity was found to differentiate well between undamaged grey, light grey and white matter.   In conclusion, blood perfusion and CSF in particular may greatly affect the lesioning process and can be important to consider when planning surgery. Reflected light intensity seems unreliable for the detection of coagulation in light grey brain matter such as the thalamus. However, it seems very promising for navigation in the brain and for detection of coagulation in other tissue types such as muscle.
68

"Modelagem computacional do manequim matemático da mulher brasileira para cálculos de dosimetria interna e para fins de comparação das frações absorvidas específicas com a mulher referência" / "Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetria and ends of comparison of the fractions absorbed specific with the woman reference"

Ximenes, Edmir 28 August 2006 (has links)
Tanto em Medicina Nuclear como em outras aplicações científicas as ferramentas para cálculos dosimétricos são de suma importância para atender os princípios básicos de proteção radiológica. Este trabalho desenvolve o manequim matemático da mulher brasileira, para ser usado como base em cálculos das Frações Absorvidas Específicas (FAEs) nos órgãos do corpo e no esqueleto, em virtude dos objetivos com relação à diagnose ou à terapia em Medicina Nuclear. O manequim ora desenvolvido é similar, na forma, ao manequim de Snyder tornando-o mais realístico para as condições antropomórficas da mulher brasileira. Para isso, utilizou-se o formalismo do método Monte Carlo, através do código computacional ALGAM-97®. Como contribuição aos objetivos deste trabalho, foi desenvolvido e implementado o sistema computacional cFAE – consulta Fração Absorvida Específica, que se torna mais versátil para a consulta do usuário pesquisador. A interface de diálogo com o operador foi projetada seguindo a atual tendência de utilização de uma linguagem orientada para o evento. Essa interface permite que o usuário navegue através dos manequins referência, escolha o órgão fonte, a energia desejada e receba as respostas num diálogo eficiente e intuitivo. O sistema fornece, além dos dados referentes à mulher brasileira, também aqueles referentes ao modelo de Snyder e ao modelo do homem brasileiro. O sistema possibilita não apenas introduzir os dados individuais para as FAEs dos três manequins, mas também a comparação entre eles. / Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97® computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF – consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several “look-up" facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them.
69

"Modelagem computacional do manequim matemático da mulher brasileira para cálculos de dosimetria interna e para fins de comparação das frações absorvidas específicas com a mulher referência" / "Computational modeling of the mathematical dummy of the Brazilian woman for calculations of internal dosimetria and ends of comparison of the fractions absorbed specific with the woman reference"

Edmir Ximenes 28 August 2006 (has links)
Tanto em Medicina Nuclear como em outras aplicações científicas as ferramentas para cálculos dosimétricos são de suma importância para atender os princípios básicos de proteção radiológica. Este trabalho desenvolve o manequim matemático da mulher brasileira, para ser usado como base em cálculos das Frações Absorvidas Específicas (FAEs) nos órgãos do corpo e no esqueleto, em virtude dos objetivos com relação à diagnose ou à terapia em Medicina Nuclear. O manequim ora desenvolvido é similar, na forma, ao manequim de Snyder tornando-o mais realístico para as condições antropomórficas da mulher brasileira. Para isso, utilizou-se o formalismo do método Monte Carlo, através do código computacional ALGAM-97®. Como contribuição aos objetivos deste trabalho, foi desenvolvido e implementado o sistema computacional cFAE – consulta Fração Absorvida Específica, que se torna mais versátil para a consulta do usuário pesquisador. A interface de diálogo com o operador foi projetada seguindo a atual tendência de utilização de uma linguagem orientada para o evento. Essa interface permite que o usuário navegue através dos manequins referência, escolha o órgão fonte, a energia desejada e receba as respostas num diálogo eficiente e intuitivo. O sistema fornece, além dos dados referentes à mulher brasileira, também aqueles referentes ao modelo de Snyder e ao modelo do homem brasileiro. O sistema possibilita não apenas introduzir os dados individuais para as FAEs dos três manequins, mas também a comparação entre eles. / Tools for dosimetric calculations are of the utmost importance for the basic principles of radiological protection, not only in nuclear medicine, but also in other scientific calculations. In this work a mathematical model of the Brazilian woman is developed in order to be used as a basis for calculations of Specific Absorbed Fractions (SAFs) in internal organs and in the skeleton, in accord with the objectives of diagnosis or therapy in nuclear medicine. The model developed here is similar in form to that of Snyder, but modified to be more relevant to the case of the Brazilian woman. To do this, the formalism of the Monte Carlo method was used by means of the ALGAM- 97® computational code. As a contribution to the objectives of this thesis, we developed the computational system cSAF – consultation for Specific Absorbed Fractions (cFAE from Portuguese acronym) - which furnishes several “look-up” facilities for the research user. The dialogue interface with the operator was planned following current practices in the utilization of event-oriented languages. This interface permits the user to navigate by means of the reference models, choose the source organ, the energy desired, and receive an answer through an efficient and intuitive dialogue. The system furnishes, in addition to the data referring to the Brazilian woman, data referring to the model of Snyder and to the model of the Brazilian man. The system makes available not only individual data to the SAFs of the three models, but also a comparison among them.
70

Metodologia para estruturação de informações de laudos radiológicos / Methodology for structuring information from radiological reports

Barbosa, Flavio 25 October 2013 (has links)
Introdução: O laudo radiológico com entrada de dados estruturada proporciona precisão na recuperação de informações, todavia, é menos abrangente que o texto-livre e pode impedir o especialista de descrever um achado importante, não contemplado pela estrutura pré-definida. Portanto, a solução está em interpretar o texto escrito pelo especialista e os transportar para uma estrutura computacional ontológica formalizando o conhecimento. Objetivos: Elaborar e avaliar uma metodologia para estruturação de informações de laudos radiológicos em texto livre que contemple as especificidades brasileiras, incluindo a terminologia empregada. Métodos: Coleta de 1701 laudos radiológicos de ressonância magnética da coluna lombossacra em três instituições distintas. Para estruturar a informação, foram utilizadas técnicas de mineração de texto e conceituação ontológica das unidades lexicais. Dez radiologistas especialistas avaliaram a superestrutura textual e a terminologia extraída e conceituada, por meio de questionário eletrônico onde foram sugeridas 3 superestruturas textuais e 30 termos com a descrição do respectivo conceito. Resultados: A metodologia criada é constituída por 6 passos: 1) coleta dos laudos radiológicos de determinado tipo de exame; 2) decomposição textual; 3) normalização das unidades lexicais; 4) identificação das superestruturas textuais; 5) conceituação dos termos candidatos; 6) avaliação das superestruturas identificadas e da terminologia extraída e conceituada pelos especialistas na linguagem de especialidade estudada. Foram identificadas três superestruturas textuais diferentes. Após processamento automático inicial, 6129 unidades lexicais foram normalizadas obtendo 4568 termos candidatos dos quais 4183 foram conceituados e originaram 727 conceitos. Foram estabelecidas 13963 relações entre termos candidatos e conceitos, e 789 relações entre conceitos. Quanto a adequada descrição dos termos, 40% dos avaliadores concordam plenamente que estão adequados, 60% concordam parcialmente que estão adequados e nenhum avaliador discordou que os termos são adequados. Em relação a quantidade de termos utilizados pelos avaliadores, em sua respectiva instituição, 70% utilizam de 24 a 30 termos e 30% de 16 a 23 termos. A conceituação de um termo foi considerada inadequada por dois avaliadores. Conclusão: A metodologia proposta foi avaliada por radiologistas especialistas que identificaram as diferenças das superestruturas textuais entre as instituições e os termos com a descrição do respectivo conceito. Portanto, foi possível estruturar a informação de laudos radiológicos da coluna lombossacra a partir do texto livre identificando as superestruturas textuais, extraindo as unidades lexicais, normalizando as unidades lexicais e conceituando ontologicamente os termos candidatos preservando a referência com as respectivas partes constituintes dos laudos radiológicos produzidos no contexto brasileiro. / Introduction: The radiological report with structured data entry provides precision in information retrieval, however, is less comprehensive than the text-free and may prevent the expert to describe an important finding, not covered by the pre-defined structure. So the solution is to interpret the text written by expert and carry for a computational framework formalizing the ontological knowledge. Objectives: Develop and evaluate a methodology for structuring information in free text radiology reports that contemplates the Brazilian specifications, including terminology. Methods: 1701 radiological reports of lumbosacral MRI were collected in three different institutions. To structure the information we used techniques of text mining and ontological conceptualization of lexical units extracted. Ten dedicated radiologists evaluated the textual superstructure and terminology extracted by the electronic questionnaire which were suggested textual 3 superstructures and 30 terms with the description of its concept. Results: The established methodology consisted of six steps: 1) collection of radiology reports of certain type of examination; 2) textual decomposition; 3) lexical units normalization; 4) textual superstructures identification ; 5) conceptualization of candidate terms; 6) evaluation of identified superstructures and terminology extracted by experts in the specialized language study. We identified three different textual superstructures. After automatic processing initial 6129 lexical units were normalized getting 4568 candidate terms of which 4183 were conceptualized and originated 727 concepts. 13963 were established relations between candidate terms and concepts and 789 relations between concepts. As for adequate description of the terms, 40% of the evaluators agree fully that are appropriate, 60% somewhat agree that they are adequate and no evaluator disagreed that the terms are adequate. Regarding the number of words used by evaluators in their respective institution using 70% between 24 and 30 terms and 30% from 16 to 23 terms. The conceptualization of a term was considered inadequate by two evaluators. The established methodology consisted of six steps: 1) collection of radiology reports of certain type of examination; 2) textual decomposition; 3) lexical units normalization; 4) textual superstructures identification ; 5) conceptualization of candidate terms; 6) evaluation of identified superstructures and terminology extracted by experts in the specialized language study. Conclusions: The proposed methodology was evaluated by radiologists who identified the differences between the textual superstructures institutions and the terms describing the relevant concept. Therefore, it was possible to structure the information of the lumbosacral spine radiology reports from free text by identifying textual superstructures, extracting lexical units, normalizing the lexical units and conceptualizing the terms ontologically candidates preserving the reference to the respective constituent parts of radiology reports produced in the Brazilian context.

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