International Organization For Standardization Research Articles

Digital twin supporting environmental performance evaluation according to ISO certification: an application case in the tire industry

ABSTRACT The link between digital evolution and environmental sustainability is reshaping how companies enhance their processes, contributing to address circular manufacturing (CM). The extant literature does not explain how to improve the tire production process to limit environmental negative impacts, which are its most critical phases, which Industry 4.0 technologies could be exploited and how they could intervene in the process to facilitate effective data management. This research proposes a framework indicating how digital technologies could support tire producers in reducing the ecological footprint of their operations. The proposed framework addresses ISO 14,046 and 14,067 International Organization for Standardization (ISO) certifications. Digital twin (DT) was chosen as the most suitable technology. The related framework was further detailed according to data-driven CM principles, providing the set of sensors to be embedded on the production process and defining the data and information to be gathered through them to address the requested ISO certifications.

Industrial sustainable Fabrication, SEM Characterization, mechanical Testing, ANOVA analysis of PP-PETF recycled Composites: Artificial intelligence and deep learning studies for nuclear shielding applications

The sustainable processing of polymeric waste is required innovation. In this article, polypropylene (PP)- polyethylene terephthalate fiber (PETF) composite materials were fabricated according to the International Organization for Standardization (ISO 9001–2 and 2008) for commercial manufacturing using extrusion and injection molding. The variations of 0, 10, 30, and 40 % of PETF loadings were utilized for mechanical properties’ optimization. The results indicate that tensile strength, strain, and young’s modulus of elasticity were in the range of 22–25 MPa, 3–5 % and 870–1167 MPa. Correspondingly, the values of flexural strength, strain and modulus constant were in the range of 39–40 MPa, 9–12 % and 1909–2140 MPa, respectively. The impact energies were in the range of 2.6–3.4 kJ/m2. Thermally, the PP-PETF composites were found stable. The scanning electron microscope characterization, presence of induced micro defects, optimum flake structure, analysis of variance, deep learning, and artificial intelligence studies predict the utilization of PP-PETF composites for manufacturing of panels and sheets regarding static loading bearing applications. The reported technical strategies can be utilized as a reference processing technique for industrial manufacturing of PP-PETF based recycled composite products.

Comparison of colorimetric methods for the analysis of total polyphenols in green tea extracts.

Two colorimetric methods are used to determine the total polyphenol contents of tea, namely, "the Folin-Ciocalteu method" defined by the International Organization for Standardization (ISO) and the "iron tartrate method" specified in the Standard Tables of Food Composition in Japan. In this study, we compared the Folin-Ciocalteu and iron tartrate methods using green tea extracts. When comparing the two methods, the sum of the four major catechins measured using high-performance liquid chromatography (HPLC) was regarded as the standard value. The total polyphenol contents obtained using the Folin-Ciocalteu method were closer to the HPLC value than those obtained using iron tartrate method. However, iron tartrate method is adequate if the current official method is improved, that is, our results suggest that the coefficients appropriate for common green tea varieties, as well as the degree and duration of cover cultivation, in the official iron tartrate method must be considered.

Effect of non-contact induction heating on HA coatings and bone cement, an ex vivo study

Background Prosthetic joint infection is a serious complication that can arise after total joint replacement surgery. When bacteria colonise an orthopaedic implant, they form biofilms that protect them from their environment, making them difficult to remove. Treatment is further complicated by a global rise of antimicrobial resistance. These protective mechanisms make treatment of prosthetic joint infection increasingly complex. Non-contact induction heating is an upcoming technology that uses heat to eradicate bacteria that are present on the surface of metallic implants. This study aims to provide insight into the feasibility of using non-contact induction heating on metallic implants that are in direct contact with other biomaterials, such as coatings composed of hydroxyapatite and bone cement composed of poly (methyl methacrylate) (PMMA). Methods Characterisation of hydroxyapatite coatings and adhesion strength tests were conducted according to standards set by the International Organisation for Standardisation (ISO 13779-2). The fixation strength of acrylic bone cement was tested according to an adapted method from ISO. Results It was found that non-contact induction heating did not significantly affect the adhesion strength of hydroxyapatite coatings (p=0.697). In contrast to hydroxyapatite coatings, acrylic bone cement softened temporarily as the temperature exceeded the glass transition temperature (83.38 ± 10.88°C). However, the induction heating temperature had no significant effect on the fixation strength after the cement was allowed to cool down (p=0.535). Conclusion This study shows the feasibility of using non-contact induction heating up to 80°C when bone cement or ceramic coatings are present in contact with infected metallic implants.

Nutritional Evaluation of Fish Scale of Selected Saline and Fresh Water Fish Species

Fish scale is the major waste materials of fish having different vital nutrients, proteins, and fatty acids. But unfortunately, it has not been drawn much attention due to want of available researches and information. So, the present research has been emphasized on the exploration of proximate compositions and fatty acid profile in two fresh water fish L. rohita and C. idella as well as saline water fish L. calcarifer and T. ilisha. All the experiments were carried out according to International Organization for Standardization (ISO) and Association of Official Analytical Chemists (AOAC). The individual percentage of fatty acid was identified and quantified, using Gas Chromatography-Flame Ionization Detector (GC-FID) and the prominent percentage of docosanoic acid was found as 25.96±0.05 %, 51.74±0.04 %, 56.58±0.01 %, and 32.88±0.04 % in L. rohita, C. idella, L. calcarifer, and T. ilisha, respectively. Besides, among the mono and poly unsaturated fatty acids, palmitoleic acid and linolenic acid were traced in higher amount respectively, in all fish species. The quality of fish scale oil was evaluated using saponification value, iodine value, ester value, acid value, percentage of free fatty acid, and percentage of glycerin that was found as 183.78±0.34 mg KOH/g, 29.93±0.21 mg I2/g, 175.31±0.31 mg KOH/g, and 17.53±0.24 mg KOH/g, in L. rohita, T. ilisha, L. rohita, and L. rohita, respectively. The proximate analyses showed that the maximum percentage of moisture (53.20±0.23 %) and lipid (1.42±0.11 %) was noticed in L. rohita whistle, the maximum percentage of ash (18.70±0.27 %) and protein (32.37±0.26 %) was found in T. ilisha. Furthermore, among the different minerals, calcium was found as higher amount than others minerals in all four species.

An improved implementation of metrological traceability concepts is needed to benefit from standardization of laboratory results.

Non-harmonization of laboratory results represents a concrete risk for patient safety. To avoid harms, it is agreed that measurements by in vitro diagnostic medical devices (IVD-MD) on clinical samples should be traceable to higher-order references and adjusted to give the same result. However, metrological traceability is not a formal claim and has to be correctly implemented, which in practice does not happen for a non-negligible number of measurands. Stakeholders, such as higher-order reference providers, IVD manufacturers, and External Quality Assessment organizers, have major responsibilities and should improve their contribution by unambiguously and rigorously applying what is described in the International Organization for Standardization 17511:2020 standard and other documents provided by the international scientific bodies, such as Joint Committee on Traceability in Laboratory Medicine and IFCC. For their part, laboratory professionals should take responsibility to abandon non-selective methods and move to IVD-MDs displaying proper selectivity, which is one of the indispensable prerequisites for the correct implementation of metrological traceability. The practicality of metrological traceability concepts is not impossible but relevant education and appropriate training of all involved stakeholders are essential to obtain the expected benefits in terms of standardization.

Verification of analytical performance of Unsaturated iron binding capacity (UIBC) assay on the Abbott Alinity ci®: Experience of the central laboratory of Mohammed VI University Hospital of Oujda

The verification of analytical methods is a requirement outlined by the International Organization for Standardization (ISO). This process involves evaluating the performance of an analytical method according to a well-defined protocol and subsequently comparing it with pre-established analytical objectives. In our study, we conducted an evaluation of the analytical performance of the unsaturated iron binding capacity assay using the Abbott kit on the Alinity CI analyzer in the biochemistry laboratory of Mohammed VI University Hospital in Oujda. The methodology employed adheres to the recommendations of the French accreditation committee (COFRAC) accreditation technical guide SH GTA 04, focusing on the assessment of reproducibility and repeatability. Overall, the results obtained from the study are considered satisfactory and align with the acceptability criteria recommended by the supplier. It's important to note that the accuracy and reliability of examination results are influenced not only by laboratory personnel, equipment, and environmental conditions, but also by the methods utilized and their eventual validation or verification.

TOXICITY OF LITHIUM BATTERY WASTE ON SELECTED INVERTEBRATES

Electronic waste poses a major menace to ecosystems owing to the toxic properties of materials used for the manufacture of electronic goods. In this present study, the toxicity of lithium battery waste on invertebrates, snails (Archachatina marginata) and earthworms (Apporrectodeal longa) were evaluated using appropriate concentrations of toxicant. The physicochemical and heavy metal analysis of the toxicant was carried out according to the method of APHA (2008). The standard protocol obtained from the Organization for Economic Cooperation and Development (OECD) and the protocol obtained from the International Organization for Standardization (ISO) were adopted for the 14-day exposure to varying concentrations of the toxicant (0.3125, 0.625, 1.25, 2.5 and 5.0 mg/kg) for earthworm and (3.125,6.25, 12.5, 25 and 50 mg/kg) for snail respectively. The pH, Electrical conductivity. Total dissolved solids, Lithium, cadmium and mercury results of the toxicant were (2.6, 13500, 8640, 36.60, 2.03 and 10.48mg/L) respectively. The result also shows an increased in the  mortality of test organisms with increase in toxicant concentration. LC50, LOEC, NOEC, TUc and TUa with exposure time for snails and earthworms were (1.05, 0.86,0.77,94.88, 129.87 mg/kg) and (0.68, 0.41,0.31, 147.06, 322.58.mg/kg), respectively. The study established that the toxicant (lithium battery) is considered a high risk to animals, plants and the environment as it adversely affects soil invertebrates which bring about soil fertility if not properly disposed of.

ISO 14001 Environmental Standard: Process Approach and Identification of Environmental Aspects and Impacts

Environmental management is the management of activities that may have an impact on the environment. It aims to limit polluting emissions and risks to the environment and to save natural resources. Often unsuspected and therefore without us always realizing it, all economic activities can have a considerable impact on the environment. Indeed, the manufacture of products requires the extraction of raw materials and the use of water and energy. Similarly, activities associated with the manufacturing process, such as maintenance, transportation; all have environmental impacts. The environmental management system is a progress tool that integrates the environmental dimension into an organization’s strategy, leading it to set objectives, achieve and maintain performance through effective management and promotes anticipation (the forecast). There is a multitude of guides allowing self-diagnosis by the organization and which make it possible to make an environmental assessment. ISO 14001 is the environmental management standard (EMS) created by the international organization for standardization. It defines the requirements of a global environmental management system for self-reporting or certification purposes. It is organized in 17 points modeled on quality management, well known for 34 years in the industry. The standard does not establish any absolute requirement for environmental performance, other than a commitment to environmental policy, to comply with legislation and the principle of continuous improvement. Pollution prevention through the identification of the various significant environmental aspects and impacts, which accounted for 70% of the requirements of ISO 14001, is the main environmental improvement point. In addition, since these environmental aspects and impacts can only be identified from the activities, products and services associated with them, this article represents a working method that allows expressing good environmental practices, present in the form of environmental performance indicators that inform in a concentrated and precise manner on the different activities with environmental relevance.

Evaluation of quality indicators in microbiology and infectious disease serology laboratory: A study from a tertiary cancer care centre in Gujarat, India

Introduction: Quality indicators (QIs) are important for the monitoring and evaluation of laboratory performance at pre-analytical, analytical, and post-analytical phases. Errors in the laboratory arise more frequently before and after the analysis of samples. The total testing process (TTP) therefore needs to be evaluated for good laboratory performance. A good quality indicator should give information about the performance of a process, thereby governing the quality of services.Objective: To analyse TTP and QIs for a period of six years of screening of laboratory performance.Methods: This retrospective analysis was conducted for the period 2017 to 2022. QIs at pre-analytical (12), analytical (04) and post-analytical (03) phases were defined and analysed on a monthly basis. The laboratory followed the guidelines of the International Organization for Standardization (ISO) 15189:2012 to identify errors in all sections.Results: A total of 259,694 samples were received during the study period. A total of 628,817 tests were performed. The overall error rate was 1.25/1000 tests. Error in the pre-analytic phase was 0.96/1000 tests, the commonest being haemolysed samples. Error in the analytical phase was 0.33/1000 tests. The error of postanalytical phase was 0.48/1000 tests with turn round time (TAT) outliers being the commonest.Conclusion: Amongst all phases of QIs, errors were minimum in the analytical phase. Continuous monitoring and analysis of QIs helps in identification of common errors in the laboratory. Corrective measures will help to improve quality of the laboratory services, and hence the patient outcome. Regular training, evaluation of technical staff, regular preventive maintenance and calibration of all analytical instruments helps in reducing the errors.

ISO 59000 Standards for the Circular Economy: a Call for Accuracy

AbstractWith the expressed aim of reducing uncertainty and lack of precision about the Circular Economy paradigm, several standards are being proposed by standard-setting bodies. The world’s most prominent body — the International Organization for Standardization — is developing the ISO 59000 family of standards to establish a common language and conceptual framework for the Circular Economy. In the light of the vigorous debate in the scientific literature about the Circular Economy, as well as criticism of the concepts involved, this perspective article calls for more precision in the definition of this type of standard.

Integrating management systems in the energy sector: the case of the electricity industry in New Zealand

The New Zealand Electricity Engineers Association (EEA) asked for advice about development of a guide for a public safety management system (PSMS) for electricity distribution networks based on ISO45001 Occupational health and safety management systems. This would help eliminate overlap between legislation and standards while maintaining compliance with legal requirements. At Victoria University of Wellington we have been working on such an integrated approach and this article reports on the project and suggests how the results can be extended to include other areas of management while retaining the ability for appropriate elements to be audited and certified in accordance with systems required by legislation. The project reviewed an earlier report and literature review on PSMS for the Electricity Networks Association. Development of the legal requirements for a PSMS were reviewed and use of the International Standards Organization (ISO) framework for all management system standards proposed to encompass ISO45001 and similar standards. Relevant management content was incorporated in the high-level structure and key stakeholders contributed technical content. Use of the ISO Annex SL as a template enabled development of an integrated management system incorporating other management system standards, that would still support legal compliance while enabling elimination of duplication and clutter, and waste of resources at a time of technology change. The work was carried out in New Zealand (NZ) and may not apply in other countries with different legal requirements. Auditors may resist integrated management systems although this may not be a limitation if documentation is appropriately written. The electricity networks businesses in NZ may move to implementation of the PSMS guide but this will be an internal decision and results may take some years to declutter documentation and reduce overlapping audits under management system standards. Over the next decade the context of the New Zealand electricity industry will undergo major shifts with the need to adapt to increasing expectations for occupational health and safety and public safety, adaptation to climate change and accelerated implementation of new technologies. The electricity industry will need to apply its resources to those changes while avoiding duplicated efforts to implement multiple management systems. Developing an integrated management system that incorporates several management systems and public safety may aid protection of non-workers who cannot otherwise be “controlled” by a business.

Evaluation of the standard test methods for optical coherence tomograph for the posterior segment of the human eye

Optical Coherence Tomography (OCT) has revolutionized retinal imaging by offering non-invasive high-resolution three-dimensional visualization capabilities. OCT has become the standard of care in routine ophthalmological practice, especially for the posterior segment. Given its widespread clinical applications, establishing standardized test devices and methods for key OCT parameters is imperative to ensure both optimal imaging performance and diagnostic accuracy and treatment effectiveness. As a widely applied standard, ISO 16971:2015 published by the International Organization for Standardization specifies the minimum requirements, test device, and methods for OCT for the posterior segment of the human eye. Notably, these standards lacked experimental validation. In the present study, we implement the test device according to ISO 16971:2015, and assess a commercially available ophthalmic OCT instrument with the suggested test device and methods. Results show that the test device and methods could facilitate a rudimentary evaluation of OCT key parameters. Nevertheless, refinements of the test device and methods are requisite to enhance measurement accuracy, reliability, traceability, and practicability, catering to the diverse needs of manufacturers, end-users, and regulatory entities.

Predicting the ultimate bearing capacity of spudcan in stiff-over-soft clay based on a failure model varying with soil parameter

A jack-up platform is prone to a ‘punch-through’ accident when working on the stiff-over-soft clay foundation. To assess the risk of punch-through, it is necessary to plot the bearing capacity-penetration curve for evaluating the penetration depth of the pile leg or to calculate the ultimate bearing capacity of the spudcan and compare it with the preload. However, accurate prediction of spudcan bearing capacity is not easy. In this paper, the failure mode about the stiff-over-soft clay under different geological conditions when punch-through occurs is discussed using coupled Eulerian lagrangian (CEL) method, varying the strength ratio between soft and stiff soil layers, the thickness of stiff soil relative to the spudcan diameter, and the non-homogeneity factor of soil strength. Based on the soil failure model with varying soil parameters, a new calculation method for ultimate bearing capacity of spudcan is proposed and then verified against existing centrifuge test results. The results show that the shape of soil shear plane in stiff clay is significantly affected by the strength ratio of soil layer and the non-homogeneity factor of soil strength. And the presented new method whose prediction errors compared with centrifuge test results are less than 5%, has better calculation accuracy than the ISO (International Organization for Standardization) method, which is valuable in guiding the calculation of the ultimate bearing capacity of the spudcan and ensuring the safe operation of the jack-up drilling units on stiff-over-soft clay.

Gross alpha/beta activity concentrations in imported bottled drinking water in Saudi Arabia

This research assessed the gross alpha and beta activity levels in bottled drinking water imported to Saudi Arabia, applying the evaluation process recommended by the World Health Organization (WHO). The WHO's approach for examining alpha and beta activity in drinking water consists of an initial phase of screening for gross alpha and beta levels to determine the need for further analysis. This is followed by a detailed assessment of specific radionuclide concentrations if initial screening levels are surpassed. The study utilized the evaporation method as a standard procedure to quantify the gross alpha and beta activity levels. Each water sample underwent evaporation, after which the activity levels of the residual matter were measured. Gross alpha activity was analyzed using a ZnS (Ag) scintillator detector system, while gross beta activity levels were gauged using a proportional counting system. The methodologies for determining gross alpha and beta activities align with the International Organization for Standardization (ISO) standards ISO 9696 and ISO 9697, respectively. The research identified the maximum alpha and beta activity levels to be 0.18 Bq/L and 0.34 Bq/L, respectively. These values were evaluated against the WHO guidance threshold values of 0.5 Bq/L for gross alpha and 1.0 Bq/L for gross beta activities, confirming that the exposure remains below the individual dose criterion of 0.1mSv/year. The estimated committed effective doses fell under the WHO's advised cap of 0.1 mSv annually, indicating the safety of the water samples for consumption. The study recommends the analysis of a larger set of samples over extended periods for increased assurance.

Pdf to Voice by Using Deep Learning

Audio books are extraordinary for people who, like most people, want to listen to themselves read. These can't be bought and stored within the library at domestic. Audiobooks are a notable manner to rest your eyes and take a damage from the steady stimulation of virtual gadgets. Others as a time shop. For instance, hold studying books even as doing exceptional responsibilities on the equal time. Not only will this lessen the issues of millennials, but it's going to also be a valuable tool for lowering human being’s visibility. The ability to transform any content material into an audiobook is a true present of humanity. Our technology may be used to develop such gadgets. Text-to-speech and other recitation applications are extensively used to assist college students broaden studying comprehension abilities. The PDF to Audio System is a screen reader designed and developed for powerful audio verbal exchange. The International Organization for Standardization (ISO) has unique PDF documents as an open file format. Document layout is one of the handiest formats for digital conversation and facts change. This is very essential if we want to improve the accessibility of our readers' display screen by adding audio to our content material. Features from PDF files encompass hyperlinks and buttons, as well as audio and video documents. Multiple languages may be supported the use of PDF-to- audio generation, which lets in customers to hear text definitely (spoken).

Debulking of the Femoral Stem in a Primary Total Hip Joint Replacement: A Novel Method to Reduce Stress Shielding.

In current-generation designs of total primary hip joint replacement, the prostheses are fabricated from alloys. The modulus of elasticity of the alloy is substantially higher than that of the surrounding bone. This discrepancy plays a role in a phenomenon known as stress shielding, in which the bone bears a reduced proportion of the applied load. Stress shielding has been implicated in aseptic loosening of the implant which, in turn, results in reduction in the in vivo life of the implant. Rigid implants shield surrounding bone from mechanical loading, and the reduction in skeletal stress necessary to maintain bone mass and density results in accelerated bone loss, the forerunner to implant loosening. Femoral stems of various geometries and surface modifications, materials and material distributions, and porous structures have been investigated to achieve mechanical properties of stems closer to those of bone to mitigate stress shielding. For improved load transfer from implant to femur, the proposed study investigated a strategic debulking effort to impart controlled flexibility while retaining sufficient strength and endurance properties. Using an iterative design process, debulked configurations based on an internal skeletal truss framework were evaluated using finite element analysis. The implant models analyzed were solid; hollow, with a proximal hollowed stem; FB-2A, with thin, curved trusses extending from the central spine; and FB-3B and FB-3C, with thick, flat trusses extending from the central spine in a balanced-truss and a hemi-truss configuration, respectively. As outlined in the International Organization for Standardization (ISO) 7206 standards, implants were offset in natural femur for evaluation of load distribution or potted in testing cylinders for fatigue testing. The commonality across all debulked designs was the minimization of proximal stress shielding compared to conventional solid implants. Stem topography can influence performance, and the truss implants with or without the calcar collar were evaluated. Load sharing was equally effective irrespective of the collar; however, the collar was critical to reducing the stresses in the implant. Whether bonded directly to bone or cemented in the femur, the truss stem was effective at limiting stress shielding. However, a localized increase in maximum principal stress at the proximal lateral junction could adversely affect cement integrity. The controlled accommodation of deformation of the implant wall contributes to the load sharing capability of the truss implant, and for a superior biomechanical performance, the collared stem should be implanted in interference fit. Considering the results of all implant designs, the truss implant model FB-3C was the best model.

Validation of Polar ElixirTM Pulse Oximeter against Arterial Blood Gases during Stepwise Steady State Inspired Hypoxia.

The purpose of this study was to evaluate the accuracy of peripheral oxygen saturation (SpO2) measurements from Polar ElixirTM pulse oximetry technology compared to arterial oxygen saturation (SaO2) measurements during acute stepwise steady state inspired hypoxia at rest. A post hoc objective was to determine if SpO2 measurements could be improved by recalibrating the Polar ElixirTM algorithm with SaO2 values from a random subset of participants. The International Organization for Standardization (ISO) protocol (ISO 80601-2-61:2017) for evaluating the SpO2 accuracy of pulse oximeter equipment was followed whereby five plateaus of SaO2 between 70-100% were achieved using stepwise reductions in inspired O2 during supine rest. Blood samples drawn through a radial arterial catheter from 25 participants were first used to compare SaO2 to SpO2 measurements from Polar ElixirTM. Then the Polar ElixirTM algorithm was recalibrated using SaO2 data from 13 random participants and SpO2 estimates were recalculated for the other 12 participants. For SaO2 values between 70-100%, root mean square error (RMSE), intraclass correlations (ICC), Pearson correlations, and Bland-Altman plots were used to assess the accuracy, agreement, and strength of relationship between SaO2 values and SpO2 values from Polar ElixirTM. The initial RMSE for Polar ElixirTM was 4.13%. After recalibrating the algorithm, the RMSE was improved to 2.67%. The ICC revealed excellent levels of agreement between SaO2 and Polar ElixirTM SpO2 values both before (ICC(3,1) = 0.837, df = 574, p < 0.001) and after (ICC(3,1) = 0.942, df = 287, p < 0.001) recalibration. Relative to ISO standards, Polar ElixirTM yielded accurate SpO2 measurements during stepwise inspired hypoxia at rest when compared to SaO2 values, which were improved by recalibrating the algorithm using a subset of the SaO2 data.

Evaluation of analytical performance of AQUIOS CL flow cytometer and method comparison with bead-based flow cytometry methods.

Given that method validation is mandatory for compliance with the International Organization for Standardization (ISO) 15,189 standard requirements, we evaluated the analytical performance of the AQUIOS CL system (Beckman Coulter) and compared it with two bead-based flow cytometry (FCM) protocols (BD FACSCAntoTM-II and Beckman Coulter DxFLEX). There are no comparative literature data on standardized protocols for counting lymphocyte subsets on the new-generation cytometer DxFLEX. We evaluated the AQUIOS CL's performance with regard to accuracy, linearity and stability by using dedicated control cell samples and patient samples. We also compared the lymphocyte counts measured on the AQUIOS CL (n=69 samples) with those measured on the BD FACSCAntoTM-II and DxFLEX FCM systems. For 61 samples, FCM results were compared with those measured on the XN-3000 Sysmex hematology analyzer. AQUIOS CL showed acceptable performance- even outside the manufacturer's quantification ranges- and strong correlations with bead-based FCM methods. The FCM techniques and the XN-3000 gave similar absolute lymphocyte counts, although values in samples with intense lymphocytosis (Bcell lymphoma/leukemia) were underestimated. The AQUIOS CL flow cytometer is a time-saving, single-platform system with good performance, especially when the manufacturer's instructions for use are followed. However, AQUIOS CL's possible limitations and pitfalls impose validation of a bead-based FCM method for immunophenotyping verification or as a back-up system. Although the DxFLEX flow cytometer is more time-consuming to use, it can provide standardized lymphocyte subset counts in case of aberrant results on AQUIOS CL or in the event of equipment failure.

The role of analytical performance specifications in international guidelines and standards dealing with metrological traceability in laboratory medicine.

The goal of metrological traceability is to have equivalent results for a measurand in clinical samples (CSs) irrespective of the in-vitro diagnostic medical device (IVD-MD) used for measurements. The International Standards Organization standard 17511 defines requirements for establishing metrological traceability of values assigned to calibrators, trueness control materials and human samples used with IVD-MDs. Each step in metrological traceability has an uncertainty associated with the value assigned to a material. The uncertainty at each step adds to the uncertainty from preceding steps such that the combined uncertainty gets larger at each step. The combined uncertainty fora CS result must fulfil an analytical performance specification (APS) for the maximum allowable uncertainty (umax CS). The umax CS can be partitioned among the steps in a metrological traceability calibration hierarachy to derive the APS for maximum allowable uncertainty at each step. Similarly, the criterion for maximum acceptable noncommutability bias can be derived from the umax CS. One of the challenges in determining if umax CS is fulfilled is determining the repeatability uncertainty (u Rw) from operating an IVD-MD within a clinical laboratory. Most of the current recommendations for estimating u Rw from internal quality control data do not use a sufficiently representative time interval to capture all relevant sources of variability in measurement results. Consequently, underestimation of u Rw is common and may compromise assessment of how well current IVD-MDs and their supporting calibration hierarchies meet the needs of clinical care providers.