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Journal of diabetes science and technology, Jan 9, 2015
Results from accuracy assessments of systems for self-monitoring of blood glucose (SMBG) are ofte... more Results from accuracy assessments of systems for self-monitoring of blood glucose (SMBG) are often visualized in difference or regression plots. These approaches become more difficult to read as the number of data points displayed increases, thus limiting their use. In the recently presented rectangle target plot (RTP) approach, data from each reagent system lot or product are displayed graphically as a single rectangle, thus allowing the plot to remain comprehensible even when displaying system accuracy data from multiple reagent system lots or products. The RTP illustrates the accuracy of SMBG systems. Each rectangle shows the mean bias and the variability of a system. By use of statistical tolerance intervals, each rectangle most closely approximates the total error for lower (<100 mg/dL) and upper (≥100 mg/dL) glucose concentrations. RTPs were created for data from 8 different manufacturers of systems for SMBG. In total, the accuracy data of 87 different reagent system lots o...
Journal of diabetes science and technology, Jan 9, 2015
The measurement accuracy of systems for self-monitoring of blood glucose (SMBG) is usually analyz... more The measurement accuracy of systems for self-monitoring of blood glucose (SMBG) is usually analyzed by a method comparison in which the analysis results are displayed using difference plots or similar graphs. However, such plots become difficult to comprehend as the number of data points displayed increases. This article introduces a new approach, the rectangle target plot (RTP), which aims to provide a simplified and comprehensible visualization of accuracy data. The RTP is based on ISO 15197 accuracy evaluations of SMBG systems. Two-sided tolerance intervals for normally distributed data are calculated for absolute and relative differences at glucose concentrations <100 mg/dL and ≥100 mg/dL. These tolerance intervals provide an estimator of where a 90% proportion of results is found with a confidence level of 95%. Plotting these tolerance intervals generates a rectangle whose center indicates the systematic measurement difference of the investigated system relative to the compa...
Diabetes technology & therapeutics, 2003
The SCGM1 System is designed to allow continuous glucose monitoring in the subcutaneous interstit... more The SCGM1 System is designed to allow continuous glucose monitoring in the subcutaneous interstitial fluid for up to 120 h. The system is based on the microdialysis technique and is composed of three components: (1) a disposable Cassette, which contains the microdialysis catheter (with the necessary tubes), an electrochemical flow-through sensor for glucose measurement, and the fluid reservoirs for both the microdialysis perfusate and a reagent solution containing glucose oxidase; (2) the Sensor Unit, which houses the Cassette and is worn by the patient using a belt pack; and (3) the Data Manager, with an integrated blood glucose meter for the calibration of the glucose signal. The Data Manager also has the option of displaying the continuous glucose signal. The Sensor Unit and Data Manager exchange glucose data and calibration data by radio transmission. In vitro precision was assessed by measurements of two standard glucose solutions (90 mg/dL, 3.4%; 360 mg/dL, 2.4%) over a time c...
Journal of diabetes science and technology, Jan 9, 2015
Results from accuracy assessments of systems for self-monitoring of blood glucose (SMBG) are ofte... more Results from accuracy assessments of systems for self-monitoring of blood glucose (SMBG) are often visualized in difference or regression plots. These approaches become more difficult to read as the number of data points displayed increases, thus limiting their use. In the recently presented rectangle target plot (RTP) approach, data from each reagent system lot or product are displayed graphically as a single rectangle, thus allowing the plot to remain comprehensible even when displaying system accuracy data from multiple reagent system lots or products. The RTP illustrates the accuracy of SMBG systems. Each rectangle shows the mean bias and the variability of a system. By use of statistical tolerance intervals, each rectangle most closely approximates the total error for lower (<100 mg/dL) and upper (≥100 mg/dL) glucose concentrations. RTPs were created for data from 8 different manufacturers of systems for SMBG. In total, the accuracy data of 87 different reagent system lots o...
Journal of diabetes science and technology, Jan 9, 2015
The measurement accuracy of systems for self-monitoring of blood glucose (SMBG) is usually analyz... more The measurement accuracy of systems for self-monitoring of blood glucose (SMBG) is usually analyzed by a method comparison in which the analysis results are displayed using difference plots or similar graphs. However, such plots become difficult to comprehend as the number of data points displayed increases. This article introduces a new approach, the rectangle target plot (RTP), which aims to provide a simplified and comprehensible visualization of accuracy data. The RTP is based on ISO 15197 accuracy evaluations of SMBG systems. Two-sided tolerance intervals for normally distributed data are calculated for absolute and relative differences at glucose concentrations <100 mg/dL and ≥100 mg/dL. These tolerance intervals provide an estimator of where a 90% proportion of results is found with a confidence level of 95%. Plotting these tolerance intervals generates a rectangle whose center indicates the systematic measurement difference of the investigated system relative to the compa...
Diabetes technology & therapeutics, 2003
The SCGM1 System is designed to allow continuous glucose monitoring in the subcutaneous interstit... more The SCGM1 System is designed to allow continuous glucose monitoring in the subcutaneous interstitial fluid for up to 120 h. The system is based on the microdialysis technique and is composed of three components: (1) a disposable Cassette, which contains the microdialysis catheter (with the necessary tubes), an electrochemical flow-through sensor for glucose measurement, and the fluid reservoirs for both the microdialysis perfusate and a reagent solution containing glucose oxidase; (2) the Sensor Unit, which houses the Cassette and is worn by the patient using a belt pack; and (3) the Data Manager, with an integrated blood glucose meter for the calibration of the glucose signal. The Data Manager also has the option of displaying the continuous glucose signal. The Sensor Unit and Data Manager exchange glucose data and calibration data by radio transmission. In vitro precision was assessed by measurements of two standard glucose solutions (90 mg/dL, 3.4%; 360 mg/dL, 2.4%) over a time c...