In required navigation performance（RNP）, total system error（TSE） is estimated to provide a timely warning in the presence of an excessive error. In this paper, by analyzing the underlying formation mechanism, the ...In required navigation performance（RNP）, total system error（TSE） is estimated to provide a timely warning in the presence of an excessive error. In this paper, by analyzing the underlying formation mechanism, the TSE estimation is modeled as the estimation fusion of a fixed bias and a Gaussian random variable. To address the challenge of high computational load induced by the accurate numerical method, two efficient methods are proposed for real-time application, which are called the circle tangent ellipse method（CTEM） and the line tangent ellipse method（LTEM）,respectively. Compared with the accurate numerical method and the traditional scalar quantity summation method（SQSM）, the computational load and accuracy of these four methods are extensively analyzed. The theoretical and experimental results both show that the computing time of the LTEM is approximately equal to that of the SQSM, while it is only about 1/30 and 1/6 of that of the numerical method and the CTEM. Moreover, the estimation result of the LTEM is parallel with that of the numerical method, but is more accurate than those of the SQSM and the CTEM. It is illustrated that the LTEM is quite appropriate for real-time TSE estimation in RNP application.展开更多
Background:In clinical laboratories,reagent depletion can significantly compromise the accuracy of K^(+),Na^(+),and Cl^(-)measurements,posing risks to patient safety.Patient-based real-time quality control(PBRTQC)has ...Background:In clinical laboratories,reagent depletion can significantly compromise the accuracy of K^(+),Na^(+),and Cl^(-)measurements,posing risks to patient safety.Patient-based real-time quality control(PBRTQC)has emerged as a valuable tool for early detection of analytical errors.However,the effectiveness of PBRTQC may be influenced using data processing methods.Among these,truncation,tail-retention,and tail-shrinkage are three commonly used data truncation techniques.Despite their potential,the clinical early-warning performance of PBRTQC with these methods under reagent depletion conditions remains unclear.Therefore,this study aims to evaluate the clinical early-warning efficacy of PBRTQC when integrated with these three data truncation methods(truncation,tail-retention,and tail-shrinkage)for K^(+),Na^(+),and Cl^(-)measurements during reagent depletion scenarios.Methods:A controlled experimental design was used with routine patient test results as the control group and simulated reagent depletion scenarios as experimental groups.PBRTQC was applied to integrated datasets processed by the three trun-cation methods.Alarm timeliness rates for detecting abnormal results were evaluated for K^(+),Na^(+),and Cl^(-).Results:Under internal standard solution depletion,the number of samples required for error detection(NPed)for K^(+)using the truncation,tail-retention,and tail-shrinkage methods was 38,10,and 10,respectively.For Na^(+),the NPed was 55,5,and 10,respectively,while for Cl^(-),it was 0,11 and 16,respectively.During diluent depletion,K^(+)and Na^(+)showed 0 with the truncation method but 10 for both the tail-retention and tail-shrinkage methods;Cl^(-)showed 0 with the truncation method but 11 with the tail-retention method and 16 with the tail-shrinkage method.With reference solution depletion,the NPed for K^(+)using the truncation,tail-retention,tail-shrinkage methods was 42,35,and 39,respectively;the NPed for Na^(+)was 135,25,and 25,respectively;and the NPed for Cl^(-)was 140,31,and 36,respectively.Conclusion:During a shortage of reagents,the effectiveness of early warning of the PBRTQC program was the highest with the tail-retention method,followed by the tail-shrinkage method.The truncation method showed the lowest effectiveness with the risk of missed error detection.Considering data variability,the tail-shrinkage method is recommended as the optimal data processing method.展开更多
基金supported by the National Basic Research Program of China (No. 2010CB731805)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 60921001)the Special Fund for Basic Research on Scientific Instruments of China (No. 2011YQ04008301)
文摘In required navigation performance（RNP）, total system error（TSE） is estimated to provide a timely warning in the presence of an excessive error. In this paper, by analyzing the underlying formation mechanism, the TSE estimation is modeled as the estimation fusion of a fixed bias and a Gaussian random variable. To address the challenge of high computational load induced by the accurate numerical method, two efficient methods are proposed for real-time application, which are called the circle tangent ellipse method（CTEM） and the line tangent ellipse method（LTEM）,respectively. Compared with the accurate numerical method and the traditional scalar quantity summation method（SQSM）, the computational load and accuracy of these four methods are extensively analyzed. The theoretical and experimental results both show that the computing time of the LTEM is approximately equal to that of the SQSM, while it is only about 1/30 and 1/6 of that of the numerical method and the CTEM. Moreover, the estimation result of the LTEM is parallel with that of the numerical method, but is more accurate than those of the SQSM and the CTEM. It is illustrated that the LTEM is quite appropriate for real-time TSE estimation in RNP application.
文摘Background:In clinical laboratories,reagent depletion can significantly compromise the accuracy of K^(+),Na^(+),and Cl^(-)measurements,posing risks to patient safety.Patient-based real-time quality control(PBRTQC)has emerged as a valuable tool for early detection of analytical errors.However,the effectiveness of PBRTQC may be influenced using data processing methods.Among these,truncation,tail-retention,and tail-shrinkage are three commonly used data truncation techniques.Despite their potential,the clinical early-warning performance of PBRTQC with these methods under reagent depletion conditions remains unclear.Therefore,this study aims to evaluate the clinical early-warning efficacy of PBRTQC when integrated with these three data truncation methods(truncation,tail-retention,and tail-shrinkage)for K^(+),Na^(+),and Cl^(-)measurements during reagent depletion scenarios.Methods:A controlled experimental design was used with routine patient test results as the control group and simulated reagent depletion scenarios as experimental groups.PBRTQC was applied to integrated datasets processed by the three trun-cation methods.Alarm timeliness rates for detecting abnormal results were evaluated for K^(+),Na^(+),and Cl^(-).Results:Under internal standard solution depletion,the number of samples required for error detection(NPed)for K^(+)using the truncation,tail-retention,and tail-shrinkage methods was 38,10,and 10,respectively.For Na^(+),the NPed was 55,5,and 10,respectively,while for Cl^(-),it was 0,11 and 16,respectively.During diluent depletion,K^(+)and Na^(+)showed 0 with the truncation method but 10 for both the tail-retention and tail-shrinkage methods;Cl^(-)showed 0 with the truncation method but 11 with the tail-retention method and 16 with the tail-shrinkage method.With reference solution depletion,the NPed for K^(+)using the truncation,tail-retention,tail-shrinkage methods was 42,35,and 39,respectively;the NPed for Na^(+)was 135,25,and 25,respectively;and the NPed for Cl^(-)was 140,31,and 36,respectively.Conclusion:During a shortage of reagents,the effectiveness of early warning of the PBRTQC program was the highest with the tail-retention method,followed by the tail-shrinkage method.The truncation method showed the lowest effectiveness with the risk of missed error detection.Considering data variability,the tail-shrinkage method is recommended as the optimal data processing method.
