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The Laboratory of Internal Dosimetry of the Center for Development of Nuclear Technology (LDI/CDTN) is responsible for routine internal monitoring of occupationally exposed individuals. The determination of photon emitting radionuclides in the human body requires calibration of the detector in specific counting geometries. The calibration process uses physical phantoms containing certified activities of the radionuclides of interest. The objective of this work was to obtain calibration efficiency curves of the Whole Body Counter in operation at the LDI/CDTN using a BOMAB physical phantom and Monte Carlo simulations.

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OBJECTIVE: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. METHODS: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. RESULTS: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly. CONCLUSIONS: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.

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Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM. Methods: This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization. Results: Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly. Conclusions: The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM. .

Objetivo: O desconforto e a falta de adaptação às interfaces de ventilação não invasiva (VNI) são obstáculos ao sucesso da VNI. A máscara facial total (MFT) é uma interface de VNI considerada muito confortável. No entanto, devido a seu grande volume interno e, consequentemente, ao aumento da reinalação de CO2, a MFT tem orifícios que permitem vazamentos proximais para melhorar a eliminação de CO2. É possível que os ventiladores usados na UTI não compensem esse vazamento adequadamente. Neste estudo, buscamos determinar se ventiladores de UTI com módulo de VNI podem ser usados com MFT com grandes vazamentos. Métodos: Estudo em simulador mecânico conduzido em um laboratório universitário de pesquisa. Oito ventiladores de UTI equipados para realizar VNI e um ventilador específico para VNI foram conectados a uma MFT com grandes vazamentos. Todos foram testados com dois níveis de positive end-expiratory pressure (PEEP, pressão expiratória final positiva) e três níveis de pressão de suporte. As variáveis analisadas foram disparo do ventilador, ciclagem, vazamento total e pressurização. Resultados: Dos oito ventiladores de UTI, quatro não funcionaram (autodisparo ou desligamento inapropriado por detecção incorreta de desconexão), três funcionaram com alguns problemas (valores baixos de PEEP ou grande atraso na ciclagem do ventilador) e apenas um funcionou adequadamente. Conclusões: A maioria dos ventiladores de UTI testados mostrou-se inadequada para VNI com MFT com grandes vazamentos. .

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Esta pesquisa objetiva recomendar especificações que os analisadores de desfibriladores e cardioversores devam apresentar, tais como: erro máximo de medição, resolução, condições de operação e recursos desejáveis. As recomendações apresentadas baseiam-se nos quesitos demandados para a realização dos ensaios previstos pelas normas NBR IEC  60601-2-4:2005 e ANSI/AAMI  DF80:2003. Uma avaliação das especificações fornecidas de quatro analisadores importados (Fluke  QED6, Fluke Impulse  7000, MTK-Biomed  Delta 3000  MKII e NETECH Delta  3000) e dois analisadores nacionais (Transmai  JM-01 e Ourox  JAU-100) também foi realizada, tendo encontrado diversas falhas de especificações em todos os analisadores. Estas falhas vão desde o não fornecimento de dados a condições aquém das desejáveis para um analisador de desfibriladores e cardioversores. Os problemas mais graves encontrados estão relacionados à não apresentação de especificações tais como precisão, exatidão de medição, erro máximo de medição ou outra informação que por sua vez auxiliaria na determinação do intervalo de abrangência para a medida, como a de energia pelo analisador Transmai  JM-01, algo inaceitável para um instrumento de medição, incertezas elevadas e condições de operação aquém das necessárias para a realização dos ensaios determinados pelas normas NBR IEC  60601-2-4:2005 e ANSI/AAMI  DF80:2003.

This study aims to recommend specifications for defibrillator and cardioverter analyzers, such as maximum permissible measurement error, resolution, operating conditions and desirable features. The recommendations are based on the test requirements from the ABNT  NBR IEC  60601-2-4:2005 and ANSI/AAMI  DF80:2003 standards. An evaluation of the specifications provided by four imported analyzers (Fluke QED 6, Fluke Impulse  7000, MTK-Biomed  Delta 3000  MKII and NETECH Delta  3000) and two Brazilian analyzers (Transmai  JM-01 and Ourox  JAU-110) has also been performed, and several problems were found with specifications of those analyzers. These problems range from unsupplied data to less than desirable conditions for a defibrillator and cardioverter analyzer. The most serious problems encountered are related to the lack of specifications such as precision, accuracy, maximum permissible measurement error or other specifications that would help determine the coverage interval of the measure, an unacceptable  mistake for a measurement instrument. Other problems were related to measurement error and operating conditions not complying with the requirements of the ABNT  NBR IEC  60601-2-4:2005 and the ANSI/AAMI  DF80:2003 standards.

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Desde los años sesenta se utilizan las señales electromoigráficas (EMG) como señales de control para prótesis actuadas por servomotores, así como en la estimulación de músculos que sufren de parálisis o de atrofia parcial. Mediante el avance tecnológico se ha logrado mejorar el diseño, así como la fabricación de sistemas protésicos, que funcionan como extensiones de algún miembro del cuerpo humano, agregando además con los nuevos diseños, características básicas como: flexibilidad, estética morfológica, incremento de la relación resistencia/peso así como multifuncionalidad. Una prótesis mioeléctrica es una estructura desarrollada con el fin de reemplazar una parte o la totalidad de un miembro del cuerpo humano, lo mismo que suplir las funciones perdidas de este, sin dejar de lado la imagen corporal del paciente. Estas prótesis son accionadas por actuadores que se controlan a través de señales EMG, las cuales se obtiene mediante agujas intramusculares superficiales o por medio de electrodos colocados en el muñón del paciente. Este tipo de prótesis es cada vez más aceptado por personas con amputación de mano, ya que proporciona un mejor desempeño y permite el incremento de funcionalidad para el paciente que la utiliza, debido a que su control es más sencillo.

Since 60’s electromiographical signals (EMG’s) are used like a control signals for prostheses acted by servomotors, as well as stimulation of muscles that are affected due to partial or total paralysis. By means of technological advance, it has been possible to improve the design as well as the production of prosthetic systems that work as extensions of some member of human body, adding with the new designs also basic characteristics as: flexibility, aesthetic morphology, and superior strength/weight relationship, as well as multi-functionality. Mioelectric prosthesis is a structure developed with the purpose of replacing a part or the entirety member of human body, same as to replace the lost functions of this, without leaving aside patient's corporal image. These prostheses are acted by actuators that are controlled through EMG signals, which are obtained by means of intramuscular or superficial needles, or by means of electrodes placed in patient's stump. This class of prostheses is more and more accepted by people with hand amputation since it provides a better acting, that which allows a superior functionality for patient that uses it, because its control is simpler.

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Este trabalho teve por objetivo o desenvolvimento e avaliação da eficácia de um protocolo de controle de qualidade de imagens geradas por equipamentos de ultrassom operando no modo B, que fosse de fácil implementação e que utilizasse um único objeto de testes. O protocolo proposto foi avaliado em 25 equipamentos de ultrassom utilizados em medicina obstétrica, ginecologia e clínica médica, selecionados em várias clínicas e hospitais de Curitiba, Brasil. Somente modelos de equipamentos que suportavam os três tipos padrões de transdutores (convexo, linear e endocavitário) foram incluídos nos testes. No entanto, em alguns dos equipamentos, nem todos os transdutores estavam disponíveis, totalizando 72 transdutores avaliados durante os testes. Um objeto de testes de uso geral foi utilizado para avaliar os seguintes parâmetros: resoluções laterais e axiais, profundidade de visualização e exatidão das distâncias medidas, entre outras. O protocolo foi implementado em duas partes: uma envolvendo a inspeção física do equipamento/monitor e outra para avaliação dos transdutores. Entre os resultados obtidos, pode-se destacar a efetividade e simplicidade do protocolo proposto, o qual é completamente baseado em um único objeto de testes. Considerando as normas e relatórios técnicos utilizados, para aproximadamente 86% dos transdutores avaliados, falhas foram detectadas em um ou mais indicadores de qualidade de imagem. Os resultados obtidos estão de acordo com outros estudos realizados no Brasil, mostrando que um grande número de equipamentos utilizados diariamente em clínicas e hospitais apresenta um ou mais parâmetros fora dos limites estabelecidos em normas técnicas, tornando difícil o diagnóstico médico e, consequentemente, submetendo o paciente a riscos.

This study aims the development of a quality control protocol of images generated by B-mode ultrasound equipment, being of simple implementation and making use of a single phantom, as well as the evaluation of the proposed protocol effectiveness. The proposed protocol was evaluated on 25 ultrasound equipment used in obstetric medicine, gynaecology and medical clinic, selected from several clinics and hospitals of Curitiba, Brazil. Only systems with three standard transducers (convex, linear and endocavitary types) should be selected, however for some units not all of them were available, thus a total of 72 transducers were tested. A general purpose phantom was used to evaluate the following parameters: lateral and axial resolution, deepness of visualization and accuracy between distances, among others. The protocol was implemented in two parts: one involving the physical inspection of the equipment/monitor and another for the transducers evaluation. Among the results obtained, one is highlighted by the effectiveness and simplicity of the proposed protocol, which is completely based on a single phantom. Considering the utilized standards and technical reports, for approximately 86% of the evaluated transducers, some kind of failure or problem was detected in one or more image quality indicators. The results, inaccordance to those obtained by other authors in Brazil, showed that agreat number of equipment used daily in clinics and hospitals present one or more parameters out of the standards, making the medical diagnosis difficult and consequently submitting the patient to risks.

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PURPOSE: To evaluate, in adults, the diagnostic accuracy of the cuff-leak test for the diagnosis of upper airway obstruction secondary to laryngeal edema and for reintubation secondary to upper airway obstruction. METHODS: Systematic review without language restrictions based on electronic databases and manual review of the literature up to December 2008. When appropriate, a random-effects meta-analysis and meta-regression (Moses' method) were performed. RESULTS: Upper airway obstruction was the outcome in nine studies with an overall incidence of 6.9%. There was significant heterogeneity among studies. The pooled sensitivity was 0.56 (95% confidence interval: 0.48-0.63), the specificity was 0.92 (95% CI: 0.90-0.93), the positive likelihood ratio was 5.90 (95% CI: 4.00-8.69), the negative likelihood ratio was 0.48 (95% CI: 0.33-0.72), and the diagnostic odds ratio was 18.78 (95% CI: 7.36-47.92). The area under the curve of the summary receiver-operator characteristic (SROC) was 0.92 (95% CI: 0.89-0.94). Only three studies have evaluated the accuracy of the cuff-leak test for reintubation secondary to upper airway obstruction. Overall incidence was 7%. The pooled sensitivity was 0.63 (95% CI: 0.38-0.84), the specificity was 0.86 (95% CI: 0.81-0.90), the positive likelihood ratio was 4.04 (95% CI: 2.21-7.40), the negative likelihood ratio was 0.46 (95% CI: 0.26-0.82), and the diagnostic odds ratio was 10.37 (95% CI: 3.70-29.13). CONCLUSIONS: A positive cuff-leak test (absence of leak) should alert the clinician of a high risk of upper airway obstruction.

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Aiming at absolute force calibration of optical tweezers, following a critical review of proposed theoretical models, we present and test the results of Mie-Debye-spherical aberration (MDSA) theory, an extension of a previous (MD) model, taking account of spherical aberration at the glass-water interface. This first-principles theory is formulated entirely in terms of experimentally accessible parameters (none adjustable). Careful experimental tests of the MDSA theory, undertaken at two laboratories, with very different setups, are described. A detailed description is given of the procedures employed to measure laser beam waist, local beam power at the transparent microspheres trapped by the tweezers, microsphere radius, and the trap transverse stiffness, as a function of radius and height in the (inverted microscope) sample chamber. We find generally very good agreement with MDSA theory predictions, for a wide size range, from the Rayleigh domain to large radii, including the values most often employed in practice, and at different chamber heights, both with objective overfilling and underfilling. The results asymptotically approach geometrical optics in the mean over size intervals, as they should, and this already happens for size parameters not much larger than unity. MDSA predictions for the trapping threshold, position of stiffness peak, stiffness variation with height, multiple equilibrium points, and "hopping" effects among them are verified. Remaining discrepancies are ascribed to focus degradation, possibly arising from objective aberrations in the infrared, not yet included in MDSA theory.

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In this study, a least squares procedure for calculating the calibration constants of a portable gamma-ray spectrometer using the general inverse matrix method is presented. The procedure weights the model equations fitting to the calibration data, taking into account the variances in the counting rates and in the radioactive standard concentrations. The application of the described procedure is illustrated by calibrating twice the same gamma-ray spectrometer, with two independent data sets collected approximately 18 months apart in the same calibration facility.

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A gamma-gamma coincidence experiment was performed to check the 152Eu 13-year decay scheme and the placement of the observed gamma-ray transitions. The multi-detector array for residual activity measurement of the Linear Accelerator Laboratory was used. The source activity was 1 MBq, and about 10(9) coincidence events were observed. About 30 gamma's were placed in the decay scheme and four 152Sm levels were added to the previously known set of levels fed in 152Eu 13-year decay.

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Since 1998, the National Laboratory for Ionizing Radiation Metrology has lead an intercomparison program for activity measurements of radiopharmaceuticals administered to patients in the Nuclear Medicine Services (NMS) with the purpose of promoting the quality control. In this work, intercomparison results with the radionuclides 67Ga, 123I, 99mTc and 201Tl from the beginning of the program to the present will be presented establishing as a consequence, the radionuclide calibrators' traceability used by the participants. The analysis of the results showed that 68% were within the limits of +/-10% required by the Brazilian Regulatory Authority that demands this accuracy band for the radiopharmaceutical measurements in the NMS. The results also demonstrate an improvement in the measurement quality that this program has provided since its beginning.

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The objective of this paper is to present our experience in the commissioning and quality assurance (QA) for intensity modulated radiotherapy (IMRT) using dynamic multileaf collimator (dMLC), sliding window technique. Using Varian equipment solution, the connectivity and operation between all IMRT chain components was checked. Then the following test were done: stability of leaf positioning and leaf speed, sensitivity to treatment interruptions (acceleration and deceleration), evaluation of standard field patterns, stability of dMLC output, segmental dose accuracy check, average leaf transmission, dosimetric leaf separation, effects of lateral disequilibrium between adjacent leaves in dose profiles and multiple carriage field verification. Standard patterns were generated for verification: uniform field, pyramid, hole, wedge, peaks and chair. Weekly QA Protocol include: sweeping gap output, Garden Fence Test (narrow bands, 2 mm wide, of exposure spaced at 2-cm intervals) and segmental dose accuracy check. Monthly QA include: sweeping gap output at multiple gantry and collimator angle, sweeping gap output off-axis, Picket Fence Test (eight consecutive movements of a 5-cm wide rectangular field spaced at 5-cm intervals), stability of leaf speed and leaf motor current test (PWM test). Patient QA procedure consists of an absolute dose measurement for all treatments fields in the treatment condition, analysis of actual leaf position versus planned leaf position (dynalog files) for each treatment field, film relative dose determination for each field, film relative dose determination for the plan (all treatment fields) in two axial planes and patient positioning verification with orthogonal films. The tests performed showed acceptable result. After more than one year of IMRT treatment the routine QA machine checks confirm the precision and stability of the IMRT system.

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A incubadora neonatal é um equipamento médico-assistencial usado para a manutenção da vida de recém-nascidos prematuros. Sua função é proporcionar um ambiente termoneutro que é obtido através do controle da temperatura e da umidade relativa do ar em níveis adequados. Isto permite que o bebê mantenha a temperatura corporal normal a baixas taxas metabólicas. Este ambiente contibui para um desenvolvimento rápido e com uma menor incidência de doenças. No presente trabalho, descreve-se um aparelho eletrônico constuído para testar incubadoras, que verifica as características do ambiente por elas proporcionado ao recém-nascido. O protótipo desenvolvido mede, no interior da incubadora, a temperatura do ar em cinco pontos diferentes, a umidade relativa, o nível sonoro e verifica o estado da velocidade do fluxo de ar. O equipamento pode funcionar no modo de coleta, onde armazena as grandezas citadas a cada minuto, permitindo uma transferência posterior dos dados para um microcomputador PC, ou no modo de teste, onde realiza testes baseados na norma NBR IEC 601-2-19. Neste último, o aparelho instrui o operador através de mensagens no visor e avisos sonoros quando ajustes devem ser feitos nos controles da incubadora, ou quando algum problema é detectado. Os resultados de testes realizados no modo de coleta, em algumas incubadoras, são apresentados.

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A análise de filmes radiográficos rejeitados serve como parâmetro para justificar um Programa de Garantia de Qualidade (PGQ). Esta análise torna possível identificar os tipos de exames em que ocorra mais frequentemente a rejeição, o tamanho de filme mais rejeitado e a causa. Permite considerar acerca da competência do pessoal técnico envolvido, problemas nos equipamentos, revelação do filme e posicionamento do paciente.

The analisys of rejected radiographic films are used like a justification to do a Quality Control Program. This analisy makes possible to identify wich is the most rejected exam type, what size of film has greater number of rejection and the cause of that. The competence of technical people involved, troubles in the equipments, in processment of the film and how to positioning pacients can be avaluated

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