RESUMO

Modern sensors deployed in most Industry 4.0 applications are intelligent, meaning that they present sophisticated behavior, usually due to embedded software, and network connectivity capabilities. For that reason, the task of calibrating an intelligent sensor currently involves more than measuring physical quantities. As the behavior of modern sensors depends on embedded software, comprehensive assessments of such sensors necessarily demands the analysis of their embedded software. On the other hand, interlaboratory comparisons are comparative analyses of a body of labs involved in such assessments. While interlaboratory comparison is a well-established practice in fields related to physical, chemical and biological sciences, it is a recent challenge for software assessment. Establishing quantitative metrics to compare the performance of software analysis and testing accredited labs is no trivial task. Software is intangible and its requirements accommodate some ambiguity, inconsistency or information loss. Besides, software testing and analysis are highly human-dependent activities. In the present work, we investigate whether performing interlaboratory comparisons for software assessment by using quantitative performance measurement is feasible. The proposal was to evaluate the competence in software code analysis activities of each lab by using two quantitative metrics (code coverage and mutation score). Our results demonstrate the feasibility of establishing quantitative comparisons among software analysis and testing accredited laboratories. One of these rounds was registered as formal proficiency testing in the database-the first registered proficiency testing focused on code analysis.

RESUMO

Quantitative real-time PCR (qPCR) is increasingly being used for the detection of bovine leukemia virus (BLV) proviral DNA. Nevertheless, quality control for the validation and standardization of such tests is currently lacking. Therefore, the present study was initiated by three Office International des Epizooties (OIE) reference laboratories and three collaborating laboratories to measure the interlaboratory variability of six already developed and available BLV qPCR assays. For that purpose, an international panel of 58 DNA samples reflecting the dynamic range of the majority of the assays was distributed to six testing centers. Based on qualitative results, the overall agreement among all six laboratories was moderate. However, significant variability in the measurement of the BLV proviral DNA copy number was observed among different laboratories. Quantitative PCR assays, even when performed by experienced staff, can yield large variability in BLV proviral DNA copy numbers without harmonization. Further standardization of different factors (i.e., utilization of unified protocols and unique calibrators) should increase interlaboratory agreement.

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Los Programas de Evaluación Externa de la Calidad (PEEC) de los laboratorios clínicos (LC) son indispensables para la comparación del desempeño en una o varias determinaciones de analitos entre diferentes laboratorios. Se evaluó el desempeño de los LC del estado Carabobo en la determinación de las concentraciones séricas de glucosa y creatinina. El estudio fue no experimental, descriptivo, de campo y de corte transversal. Se evaluaron 22 laboratorios entre públicos y privados del estado Carabobo. Se distribuyeron a cada LC 5 sueros controles (SC) nivel I (NI) y 5 nivel II (NII) para glucosa y creatinina. Se evaluó la imprecisión intra- e interlaboratorios, el sesgo y el error total de los resultados. No hubo LC con competencia para la determinación de glucosa y creatinina en ambos niveles ensayados. Solo 3 (13,3%) LC fueron competentes en la determinación de creatinina en el NI y NII. Se concluye que los resultados obtenidos en los SC de glucosa y creatinina no pueden ser transferibles entre los diferentes LC, por lo que es importante poner en marcha programas de control de calidad intralaboratorios o mejorar los existentes para eliminar los errores sistemáticos y disminuir los aleatorios, así como también se hace necesaria la participación en PEEC para determinar la universalización de los resultados emitidos por los LC.

External Quality Assessment Schemes (EQAS) of clinical laboratories (CL) are indispensable to compare performance in one or more analyte determinations among different laboratories. Performance of CL in Carabobo state for the determination of serum glucose and creatinine was evaluated. The study was not experimental, descriptive and cross-sectional field. A total of 22 public and private laboratories in Carabobo state were evaluated. Each CL was distributed 5 control sera (CS) level I (LI) and 5 level II (LII) for glucose and creatinine. Intra- and inter-laboratory precision, bias and total error of the results were evaluated. There was no CL competition for determining glucose and creatinine both levels tested. Only 3 (13.3%) CL were proficient in the determination of creatinine in the LI and LII. It can be concluded that the results obtained in CS glucose and creatinine may not be transferable between different CL, so it is important to implement quality control programs within laboratories or improve the existing ones to eliminate systematic errors and reduce randomization; besides, participation in EQAS is also necessary to determine the universalization of the CL results.

Os Programas de Avaliação Externa da Qualidade (PAEQ) dos laboratórios clínicos (LC) são essenciais para comparar o desempenho numa ou varias determinações de analitos entre diferentes laboratórios. Avaliou--se o desempenho dos LC do estado Carabobo na determinação das concentrações séricas de glicose e creatinina. O estudo foi não experimental, descritivo, de campo e seção transversal. Avaliaram-se 22 laboratórios entre públicos e privados do estado Carabobo. Foram distribuídos a cada laboratórios 5 soros controle (SC) nível I (NI) y 5 soros controle nível II (NII) para a glicose e creatinina. Foi avaliada a imprecisão intra e inter-laboratórios, o desvio percentual relativo e o erro total dos resultados. Não houve LC com competência para a determinação de glicose e creatinina em ambos os níveis testados. Apenas 3 (13,3%) LC foram competentes na determinação de creatinina no NI e NII. Conclui-se que os resultados obtidos nos SC de glicose e creatinina não podem ser transferíveis entre os diferentes LC, por isso é importante implementar programas de controle de qualidade intralaboratórios ou melhorar os já existentes para eliminar erros sistemáticos e reduzir os aleatórios; bem como se torna necessária a participação em PAEQ, para determinar a universalização dos resultados emitidos pelos LC.

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The Secondary Standard Dosimetry Laboratory of Cuba has implemented the calibration methodology of well-type chambers using the high dose rate sources. The use of different source types, at the hospital site as a modification of the procedure using other source types in a permanent facility of the primary laboratory leads to the need to evaluate the performance of the secondary procedure for calibration. The present paper describes the proficiency test to Cuban laboratory by making a comparison of dosimetry standards used in Germany and Cuba.

El Laboratorio Secundario de Calibración Dosimétrica de Cuba ha implementado una metodología para calibrar cámaras de pozo utilizando fuentes de de altas tasas de dosis. El uso de diferentes tipos de fuentes, como parte de una modificación del procedimiento con otro tipo de fuente usada en una instalación permanente del laboratorio primario, provocó la necesidad de evaluar el desempeño del procedimiento secundario de calibración. El trabajo describe el ensayo de aptitud al laboratorio cubano mediante un ejercicio de comparación entre los patrones dosimétricos de Alemania y Cuba.

RESUMO

Five statistical approaches were applied for assessing the performance of participants in 19 rounds (2007-2011) of the Proficiency Testing Program for lead in blood determination (PEP-Pbs), conducted by Instituto Adolfo Lutz. The performance evaluation was provided by using the z-score. The following statistical approaches were tested: 1 mean and standard deviation, after rejecting outliers; 2 median and normalized inter-quartile range; 3 robust mean and robust standard deviation; 4 robust mean and standard deviation for proficiency assessment of 3 µg/100 mL (for concentrations up to 40 µg/100 mL and a standard deviation for proficiency assessment of 7.5 % of the assigned value (for concentrations above 40 µg/100 mL); 5 robust mean and standard deviation for proficiency assessment of 2 µg/100 mL (for concentration up to 40 µg/100 mL) or 5 % of the assigned value (for concentrations above 40 µg/100 mL). The approach 4 showed to be the most adequate statistical methodology to assess the performance of participating laboratories in the PEP-Pbs.(AU)

Cinco abordagens estatísticas foram aplicadas para avaliar o desempenho dos participantes em 19 rodadas (2007-2011) do Programa de Ensaio de Proficiência para determinação de chumbo em sangue (PEP-Pbs), organizado pelo Instituto Adolfo Lutz. A avaliação de desempenho foi realizada utilizando-se o índice-z, e as seguintes abordagens estatísticas foram testadas: 1 - média e desvio padrão, após a exclusão dos valores dispersos; 2 - mediana e intervalo interquartil normalizado; 3 - média robusta e desvio padrão robusto; 4 - média robusta e desvio padrão de proficiência de 3 µg/100 mL (para concentrações de até 40 µg/100 mL) e desvio padrão de proficiência de 7,5 % do valor designado (para concentrações superiores a 40 µg/100 mL); 5 - média robusta, desvio padrão de proficiência de 2 µg/100 mL (para concentrações de até 40 µg/100 mL) e desvio padrão de proficiência de 5 % do valor designado (para concentrações acima de 40 µg/100 mL). A abordagem 4 mostrouser mais adequada para avaliar o desempenho dos laboratórios participantes do PEP-Pbs.(AU)

Assuntos

RESUMO

Five statistical approaches were applied for assessing the performance of participants in 19 rounds(2007-2011) of the Proficiency Testing Program for lead in blood determination (PEP-Pbs), conducted by Instituto Adolfo Lutz. The performance evaluation was provided by using the z-score. The following statistical approaches were tested: 1 – mean and standard deviation, after rejecting outliers; 2 – median and normalized inter-quartile range; 3 – robust mean and robust standard deviation; 4 – robust meanand standard deviation for proficiency assessment of 3 μg/100 mL (for concentrations up to 40 μg/100mL and a standard deviation for proficiency assessment of 7.5 % of the assigned value (for concentrations above 40 μg/100 mL); 5 – robust mean and standard deviation for proficiency assessment of 2 μg/100 mL(for concentration up to 40 μg/100 mL) or 5 % of the assigned value (for concentrations above 40 μg/100mL). The approach 4 showed to be the most adequate statistical methodology to assess the performance of participating laboratories in the PEP-Pbs...

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En el trabajo se presentan los principales resultados obtenidos por el Departamento de Metrología de Radionúclidos del Centro de Isótopos, concernientes al establecimiento de patrones de medición de la actividad (becquerel) de los radionúclidos emisores gamma y beta, así como la diseminación de la unidad hasta los usuarios finales. Se resume la participación del Departamento en los últimos 5 años en comparaciones claves y suplementarias del Órgano de Cooperación Euroasiática de Institutos Metrológicos Nacionales, en comparaciones bilaterales realizadas con laboratorios metrológicos de otros países, así como ejercicios de aptitud organizados por el Organismo Internacional de Energía Atómica. Se ofrece información acerca de la importancia del reconocimiento internacional alcanzado de las capacidades de medición y calibración del Departamento mediante su inclusión en el Anexo C de la base datos de comparaciones claves del Buró Internacional de Pesos y Medidas. Se señalan los proyectos actuales que se ejecutan como elementos fundamentales para garantizar el aseguramiento metrológico indispensable a los desarrollos previsibles en la medicina nuclear y la radioterapia con fuentes no encerradas.

The paper presents the main achievements of the Department of Radionuclide Metrology at the Isotope Centre, concerning the establishment of measurement standards of the activity (Bq) of gamma and beta emitting radionuclides, as well as the dissemination of the unit to end users. It highlights the participation of the department in the last five years in key and supplementary comparisons organized in the frame of the regional Euro-Asian Cooperation of National Metrological Institutes and bilateral inter-laboratory comparisons, as well as in proficiency tests organized by International Atomic Energy Agency. It provides information about the importance of international recognition achieved, and the calibration and measurement capabilities of the department through its inclusion in Annex C of the database of key comparisons of the International Bureau of Weights and Measures. Current projects that are being implemented as basic elements for metrological assurance essential to foreseeable developments in nuclear medicine and radiation therapy with unsealed sources are identified.

RESUMO

O aumento de florações de cianobactérias em mananciais utilizados para abastecimento é uma preocupação global. Seguindo as diretrizes da Organização Mundial da Saúde, a portaria nº 518/2004 do Ministério da Saúde, determina o monitoramento de cianobactérias nos mananciais superficiais e, quando for o caso, na água tratada. No Brasil, não há padronização de métodos de análise; assim, os métodos utilizados devem fornecer resultados confiáveis. Por meio da participação voluntária, um programa de ensaios de proficiência em cianobactérias foi realizado em 2010. Este trabalho apresenta o diagnóstico do desempenho dos laboratórios na identificação e contagem de cianobactérias. Os resultados das contagens foram submetidos ao cálculo do escore z, obtendo-se 80 por cento de laboratórios com desempenho satisfatório. Divergências foram observadas na identificação dos gêneros de cianobactérias.

The increase of cyanobacterial blooms in water sources used for supply is a global concern. Following the guidelines of the World Health Organization, ordinance nº 518/2004, the of the Ministry of Health, provides the monitoring of cyanobacteria in superficial water sources and, when appropriate, in treated water. In Brazil, there is no standardization of analysis methods; thus, the applied methods should provide reliable results. Through voluntary participation, a proficiency testing program in cyanobacteria was conducted in 2010. This paper presents the diagnostic performance of laboratories in identification and counting of cyanobacteria. Results of counts were subjected to the calculation of z-score, and 80 percent of laboratories presented satisfactory performance. Differences were observed in the identification of cyanobacterial genera.

RESUMO

RESUMEN En medicina nuclear, las dosis del radiofármaco administradas se expresan mediante la actividad del radionucleido en el preparado. La medición de esa actividad se realiza en el activímetro y resulta primordial para garantizar la comparabilidad nacional e internacional de los resultados clínicos relacionados y la seguridad radiológica del paciente. En este trabajo se detalla la transferencia de la unidad becquerel a los activímetros empleados en medicina nuclear en Cuba. Se presentan los resultados de la implantación de un servicio de calibración in situ, basado en la comparación directa con muestras de referencia de los radionucleidos específicos sujetos a medición. Los resultados de las comparaciones de medición internacionales y nacionales que se muestran, validan los estimados de incertidumbre de los coeficientes de calibración, determinados para la medida en estos instrumentos de la actividad de los principales emisores gamma que se han utilizado en la medicina nuclear cubana: technetium 99,iodine 131, radiopharmaceuticals thallium 201.

ABSTRACT In nuclear medicine, the administered doses of the radiopharmaceutical are expressed through the amount of radioactivity contained in the drug. The measurement of this activity, performed using a radionuclide calibrator, is of the utmost importance to guarantee the national and international comparability of clinic results and the radiological safety of the patient. In this paper, the transferring of the becquerel unit to the radionuclide calibrators employed in the nuclear medicine practice in Cuba is detailed. The obtained results with an in situ calibration service, which is based on the direct comparison with standards of the specific measured radionuclides, are presented. Outcomes of international and national measurement comparisons are shown. They validate the uncertainty estimates of the calibration coefficients installed in the instruments for measurements of technetium 99,iodine 131, radiopharmaceuticals thallium 201, the main gamma emitters that have been used in Cuban nuclear medicine.

RESUMO

Se presentan los resultados de la comparación nacional de la medición de actividad de 131I con activímetros, organizada en Cuba en el 2007. Estos resultados contribuyen a establecer la incertidumbre y la trazabilidad de los valores de actividad de 131I, determinados en los activímetros de las diferentes instituciones participantes: 9 hospitales y dos laboratorios del Centro de Isótopos que participaron directamente en la producción de los radiofármacos. Si consideramos solamente la proporción de resultados satisfactorios, el desempeño evidenciado por los participantes es igual al alcanzado en las comparaciones de este tipo, organizadas del 2002 al 2004 en el país. No obstante, la estimación razonable de la incertidumbre de la actividad de 131I medida en el activímetro, realizada por la mayoría de los participantes en el 2007, muestra un resultado cualitativamente superior con respecto al obtenido en el 2002-2004. Se reportaron los resultados del ejercicio bilateral de medición de 131I entre el Departamento de Metrología de Radionúclidos del Centro de Isótopos y el Laboratorio Nacional de Metrología de las Radiaciones Ionizantes del Instituto de Protección Radiológica y Dosimetría de Brasil. Concebido como complemento de la comparación nacional, este ejercicio bilateral proporciona evidencias adicionales de la comparabilidad de los patrones de medición utilizados para calibrar las disoluciones y muestras de referencia de 131I en el Departamento de Metrología de Radionúclidos del Centro de Isótopos.

Results from the national comparison of 131I activity measurements with radionuclide calibrators in Nuclear Medicine, organized in Cuba in 2007, are shown. These results contribute to establish the uncertainty and traceability of the 131I activity values measured with radionuclide calibrators of the participating institutions: 9 hospitals and two laboratories of the Isotope Centre directly involved in radiopharmaceuticals’ production. Concerning the proportion of acceptable results, no improvement was observed in the participants’ performance compared to results shown in such kind of exercises organized in the country during 2002-2004. On the other hand, the reasonable uncertainty estimate of the 131I measurements reported by most of the participants show a qualitatively superior outcome in 2007 compared to the result obtained in the previously organized exercises. Moreover, the outcome of the bilateral comparison for 131I activity measurements between the Radionuclide Metrology Department of the Isotope Centre (CENTIS-DMR) and the National Metrology Laboratory for Ionizing Radiation of the Brazilian Institute of Radiation Protection and Dosimetry (LNMRI-IRD) is also shown. This bilateral exercise provides additional evidences on comparability of the CENTIS-DMR measurement standards used to calibrate 131I reference solutions and samples.