scholarly journals Computer Aided Quality Control in Clinical Chemistry

2017 ◽  
Author(s):  
Aristeidis T. Chatzimichail
Keyword(s):  
Quality Control ◽  
Clinical Chemistry ◽  
Chemistry Laboratory ◽  
Design Evaluation ◽  
Control Procedure ◽  
Quality Control Procedure ◽  
Control Procedures ◽  
Definition Of ◽  
Optimal Quality ◽  
Selection Of

This doctoral thesis describes a series of tools that have been developed for the design, evaluation, and selection of optimal quality control procedures, in a clinical chemistry laboratory setting. These tools include: 1) A simulation program for the design, evaluation, and comparison of alternative quality control procedures. The program allows (a) the definition of a very large number of quality control rules, and (b) the definition of the quality control procedures as boolean propositions of any degree of complexity. The program elucidates the ways the error is introduced into the measurements and describes the respective methods of simulation. Therefore, it allows the study of the performance of the quality control procedures when (a) there is error in all the measurements, (b) the error is introduced between two consecutive analytical runs, and (c) the error is introduced within an analytical run, between two consecutive control samples. 2) A library of fifty alternative quality control procedures. 3) A library of the power function graphs of these procedures. 4) A program for the selection of the optimal quality control procedure of the library, given an analytical process. As optimal quality control procedure is considered the procedure that detects the critical errors with stated probabilities and the minimum probability for false rejection. A new general system of equations is proposed for the calculation of the critical errors.

scholarly journals A novel quality control procedure for the evaluation of laser scanning data segmentation

2014 ◽  
Vol XL-1 ◽  
pp. 207-210 ◽  
Author(s):  
Z. Lari ◽  
K. Al-Durgham ◽  
A. Habib
Keyword(s):  
Quality Control ◽  
Laser Scanning ◽  
Control Procedure ◽  
Quality Control Procedure ◽  
Data Segmentation ◽  
Control Procedures ◽  
Scanning Systems ◽  
Quality Control Techniques ◽  
User Intervention ◽  
Selection Of

Over the past few years, laser scanning systems have been acknowledged as the leading tools for the collection of high density 3D point cloud over physical surfaces for many different applications. However, no interpretation and scene classification is performed during the acquisition of these datasets. Consequently, the collected data must be processed to extract the required information. The segmentation procedure is usually considered as the fundamental step in information extraction from laser scanning data. So far, various approaches have been developed for the segmentation of 3D laser scanning data. However, none of them is exempted from possible anomalies due to disregarding the internal characteristics of laser scanning data, improper selection of the segmentation thresholds, or other problems during the segmentation procedure. Therefore, quality control procedures are required to evaluate the segmentation outcome and report the frequency of instances of expected problems. A few quality control techniques have been proposed for the evaluation of laser scanning segmentation. These approaches usually require reference data and user intervention for the assessment of segmentation results. In order to resolve these problems, a new quality control procedure is introduced in this paper. This procedure makes hypotheses regarding potential problems that might take place in the segmentation process, detects instances of such problems, quantifies the frequency of these problems, and suggests possible actions to remedy them. The feasibility of the proposed approach is verified through quantitative evaluation of planar and linear/cylindrical segmentation outcome from two recently-developed parameter-domain and spatial-domain segmentation techniques.

scholarly journals Expanding HadISD: quality-controlled, sub-daily station data from 1931

2016 ◽  
Author(s):  
Robert J. H. Dunn ◽  
Kate M. Willett ◽  
David E. Parker ◽  
Lorna Mitchell
Keyword(s):  
Quality Control ◽  
Wind Speed ◽  
Time Range ◽  
Underlying Structure ◽  
Control Procedure ◽  
Future Projections ◽  
Quality Control Procedure ◽  
Temporal Coverage ◽  
Extremes Of Temperature ◽  
Selection Of

Abstract. HadISD is a sub-daily, station-based, quality-controlled dataset designed to study past extremes of temperature, pressure and humidity and allow comparisons to future projections. Herein we describe the first major update to the HadISD dataset. The temporal coverage of the dataset has been extended to 1931 to present, doubling the time range over which data are provided. Improvements made to the station selection and merging procedures result in 7677 stations being provided in version 2.0.0.2015p of this dataset. The selection of stations to merge together making composites has also been improved and made more robust. The underlying structure of the quality control procedure is the same as for HadISD.1.0.x, but a number of improvements have been implemented in individual tests. Also, more detailed quality control tests for wind speed and direction have been added. The data will be made available as netCDF files at www.metoffice.gov.uk/hadobs/hadisd and updated annually.

scholarly journals Expanding HadISD: quality-controlled, sub-daily station data from 1931

2016 ◽  
Vol 5 (2) ◽  
pp. 473-491 ◽  
Author(s):  
Robert J. H. Dunn ◽  
Kate M. Willett ◽  
David E. Parker ◽  
Lorna Mitchell
Keyword(s):  
Quality Control ◽  
Wind Speed ◽  
Time Range ◽  
Underlying Structure ◽  
Control Procedure ◽  
Future Projections ◽  
Quality Control Procedure ◽  
Temporal Coverage ◽  
Extremes Of Temperature ◽  
Selection Of

Abstract. HadISD is a sub-daily, station-based, quality-controlled dataset designed to study past extremes of temperature, pressure and humidity and allow comparisons to future projections. Herein we describe the first major update to the HadISD dataset. The temporal coverage of the dataset has been extended to 1931 to present, doubling the time range over which data are provided. Improvements made to the station selection and merging procedures result in 7677 stations being provided in version 2.0.0.2015p of this dataset. The selection of stations to merge together making composites has also been improved and made more robust. The underlying structure of the quality control procedure is the same as for HadISD.1.0.x, but a number of improvements have been implemented in individual tests. Also, more detailed quality control tests for wind speed and direction have been added. The data will be made available as NetCDF files at http://www.metoffice.gov.uk/hadobs/hadisd and updated annually.

scholarly journals Expanding HadISD: quality-controlled, sub-daily station data from 1931

2015 ◽  
Vol 11 (5) ◽  
pp. 4569-4600 ◽  
Author(s):  
R. J. H. Dunn ◽  
K. M. Willett ◽  
D. E. Parker ◽  
L. Mitchell
Keyword(s):  
Quality Control ◽  
Wind Speed ◽  
Time Range ◽  
Underlying Structure ◽  
Control Procedure ◽  
Quality Control Procedure ◽  
Station Data ◽  
Temporal Coverage ◽  
Over Time ◽  
Selection Of

Abstract. We describe the first major update to the sub-daily station-based HadISD dataset. The temporal coverage of the dataset has been extended to 1931 to present, doubling the time range over which data are provided. Improvements made to the station selection and merging procedures result in 8113 stations being provided in version 2.0.0.2014f of this dataset. This station selection will be reassessed at every annual update, which is likely to result in increasing station numbers over time. The selection of stations to merge together making composites has also been improved and made more robust. The underlying structure of the quality control procedure is the same as for HadISD.1.0.x, but a number of improvements have been implemented in individual tests. Also, more detailed quality control tests for wind speed and direction have been added. The data will be made available as netCDF files at www.metoffice.gov.uk/hadobs/hadisd and updated annually.

Practice of patient based quality assessment procedure in clinical chemistry unit at diagnostic laboratories in Nepal

2013 ◽  
Vol 1 (1) ◽  
pp. 9-17
Author(s):  
P Gyawali ◽  
S Tamrakar ◽  
N Lamsal ◽  
RK Shresta
Keyword(s):  
Quality Control ◽  
Clinical Laboratory ◽  
Clinical Chemistry ◽  
Vital Role ◽  
Control Procedure ◽  
Assessment Procedure ◽  
Random Errors ◽  
Quality Control Procedure ◽  
Total Testing Process ◽  
Analytical Errors

Background: The clinical laboratory is the major producer of information used to diagnose, treat, and monitor patients. Errors in laboratory testing may occur at many different points in the total testing process (TTP). Application of quality control plays a vital role in recognizing probable errors. The current dominant technique for error identification uses quality control materials has several inherent drawbacks; otherwise, patient based quality control procedure ensures the detection of pre-analytical errors, analytical, post-analytical errors, clerical errors, and random errors that cannot be detected using commonly used quality control methods, thereby improving the reliability of clinical tests. Objective: Thus the objective of this study was to evaluate the practice of patient based quality control procedure in clinical chemistry unit at diagnostic laboratories in Nepal. Materials and Methods: The questionnaire based study was conducted in clinical chemistry unit of diagnostic laboratories across the country. Questionnaires were personally dropped in 217 clinical biochemistry laboratories and were asked to complete a practice based questionnaire. The responses of 169 laboratories were analyzed using Microsoft Excel 2007 and expressed in terms of percentage. Results: In foremost study undertaken, a total of 169 laboratories responded to the questionnaire. A total 65.9 % of the laboratories monitored errors using patient based quality control procedure but not as a part of quality control. Very few of participant.s laboratories responded accurately regarding utility and practical aspects of patient based quality control included in the checklist. Conclusion: Practice of patient based quality control procedure was not well established to identify possible errors. Hence, the study extent the existing information and explored that the current classical approaches were not adequate to assure accurate patients test results for specific analytes. DOI: http://dx.doi.org/10.3126/stcj.v1i1.7983 Sunsari Technical College Journal Vol.1(1) 2012 9-17

scholarly journals Аnalysis of the technical and dosimetric characteristics of the brachytherapy afterloaders. Ring applicator

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 13-20
Author(s):  
D. I. Kazlouski ◽  
Y. V. Titovich ◽  
Y. I. Kazlouskaya
Keyword(s):  
Quality Control ◽  
Treatment Plan ◽  
The Body ◽  
Control Procedure ◽  
Reconstruction Method ◽  
X Ray ◽  
Quality Control Procedure ◽  
Treatment Plans ◽  
Control Procedures

A study of the technical and dosimetry characteristics of brachytherapy afterloaders and applicators was carried out. Ring applicator has been taken as an example, the correctness of positioning of a radiation source (RS) inside the applicators was tested as part of the comissioning and quality control procedure of the brachytherapy applicators. The magnitudes of inconsistencies in the position of RS were established when planning and implementing treatment plans for radiation therapy. The identification of the values of the discrepancy was carried out using the obtained X-ray images of the applicator at the time of the implementation of the irradiation plans. The treatment plan was a sequential positioning of RS in the body of the applicator in each active position with a minimum step from the tip to the vaginal part of the applicator. The X-ray image was obtained by locating the source sequentially at each active position of the applicator. When carrying out dosimetric planning, 3 methods of applicator reconstruction were used. The analysis revealed that the applicator reconstruction method affects the magnitude of the discrepancy in determining the position of the source in the lumen of the applicator ring. Using the methods of statistical analysis, the mean, median, maximum and minimum values of the detected deviations were calculated. The results are presented in the form of tables and graphs for all investigated stop positions of IRS. Based on the results of the study, we consider it expedient to carry out quality control procedures when putting applicators into clinical operation. Based on the results obtained, we consider it acceptable to conduct a quality control procedure for the positioning accuracy of radiation sources in the applicators at least 1 time per month. Taking into account the results of the study when carrying out dosimetric planning will improve the quality of the irradiation sessions using the brachytherapy method, thereby improving the quality of oncological care for the population.

scholarly journals Migration from NetWISP to Nutritics – a quality control procedure

2018 ◽  
Vol 77 (OCE3) ◽  
Author(s):  
S. Cassidy ◽  
B. Phillips ◽  
J. Caldeira Fernandes da Silva ◽  
A. Parle
Keyword(s):  
Quality Control ◽  
Control Procedure ◽  
Quality Control Procedure

scholarly journals Automated Quality Control of In Situ Soil Moisture from the North American Soil Moisture Database Using NLDAS-2 Products

2015 ◽  
Vol 54 (6) ◽  
pp. 1267-1282 ◽  
Author(s):  
Youlong Xia ◽  
Trent W. Ford ◽  
Yihua Wu ◽  
Steven M. Quiring ◽  
Michael B. Ek
Keyword(s):  
Quality Control ◽  
Soil Moisture ◽  
North American ◽  
Soil Layer ◽  
Control Procedure ◽  
Multiple Model ◽  
Quality Control Procedure ◽  
The North ◽  
Automated Quality Control

AbstractThe North American Soil Moisture Database (NASMD) was initiated in 2011 to provide support for developing climate forecasting tools, calibrating land surface models, and validating satellite-derived soil moisture algorithms. The NASMD has collected data from over 30 soil moisture observation networks providing millions of in situ soil moisture observations in all 50 states, as well as Canada and Mexico. It is recognized that the quality of measured soil moisture in NASMD is highly variable because of the diversity of climatological conditions, land cover, soil texture, and topographies of the stations, and differences in measurement devices (e.g., sensors) and installation. It is also recognized that error, inaccuracy, and imprecision in the data can have significant impacts on practical operations and scientific studies. Therefore, developing an appropriate quality control procedure is essential to ensure that the data are of the best quality. In this study, an automated quality control approach is developed using the North American Land Data Assimilation System, phase 2 (NLDAS-2), Noah soil porosity, soil temperature, and fraction of liquid and total soil moisture to flag erroneous and/or spurious measurements. Overall results show that this approach is able to flag unreasonable values when the soil is partially frozen. A validation example using NLDAS-2 multiple model soil moisture products at the 20-cm soil layer showed that the quality control procedure had a significant positive impact in Alabama, North Carolina, and west Texas. It had a greater impact in colder regions, particularly during spring and autumn. Over 433 NASMD stations have been quality controlled using the methodology proposed in this study, and the algorithm will be implemented to control data quality from the other ~1200 NASMD stations in the near future.

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