Accuracy and precision assessment of a new blood glucose monitoring system

Author(s):  
Li-Nong Ji ◽  
Li-Xin Guo ◽  
Li-Bin Liu

AbstractBlood glucose self-monitoring by individuals with diabetes is essential in controlling blood glucose levels. The International Organization for Standardization (ISO) introduced new standards for blood glucose monitoring systems (BGMS) in 2013 (ISO 15197: 2013). The CONTOUR PLUSThis study evaluated the accuracy and precision of CONTOUR PLUS BGMS in quantitative glucose testing of capillary and venous whole blood samples obtained from 363 patients at three different hospitals.Results of fingertip and venous blood glucose measurements by the CONTOUR PLUS system were compared with laboratory reference values to determine accuracy. Accuracy was 98.1% (96.06%–99.22%) for fingertip blood tests and 98.1% (96.02%–99.21%) for venous blood tests. Precision was evaluated across a wide range of blood glucose values (5.1–17.2 mmol/L), testing three blood samples repeatedly 15 times with the CONTOUR PLUS blood glucose meter using test strips from three lots. All within-lot results met ISO criteria (i.e., SD<0.42 mmol/L for blood glucose concentration <5.55 mmol/L; CV<7.5% for blood glucose concentration ≥5.55 mmol/L). Between-lot variations were 1.5% for low blood glucose concentration, 2.4% for normal and 3.4% for high.Accuracy of both fingertip and venous blood glucose measurements by the CONTOUR PLUS system was >95%, confirming that the system meets ISO 15197: 2013 requirements.

2021 ◽  
Author(s):  
◽  
G. Silos Chincoya

This researching study aims to report the development of a prototype device that may provide the estimation of the blood glucose concentration levels non-invasively using near-infrared transmission spectroscopy techniques. The system works in three stages: signal acquisition, calibration, and estimation of blood glucose concentration levels. The acquisition of the signal used an optical sensor based on a transimpedance circuit to obtain the different intensity changes of the emitting source in terms of voltage. The calibration of the proposed device was carried out taking as reference, the values of a commercial device that performs invasive blood glucose monitoring, with the aim of obtaining greater precision. In the last stage, the Lambert-Beer Law is mainly used to estimate glucose concentration. The proposed device presents a relationship between optical signals and variations in blood glucose levels with an accuracy of 90% in average which is statistically representative considering the class of non-invasive technology used for developing the proposed device.


Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6871
Author(s):  
Lukas Malena ◽  
Ondrej Fiser ◽  
Paul R. Stauffer ◽  
Tomas Drizdal ◽  
Jan Vrba ◽  
...  

The use of microwave technology is currently under investigation for non-invasive estimation of glycemia in patients with diabetes. Due to their construction, metamaterial (MTM)-based sensors have the potential to provide higher sensitivity of the phase shift of the S21 parameter (∠S21) to changes in glucose concentration compared to standard microstrip transmission line (MSTL)-based sensors. In this study, a MSTL sensor and three MTM sensors with 5, 7, and 9 MTM unit cells are exposed to liquid phantoms with different dielectric properties mimicking a change in blood glucose concentration from 0 to 14 mmol/L. Numerical models were created for the individual experiments, and the calculated S-parameters show good agreement with experimental results, expressed by the maximum relative error of 8.89% and 0.96% at a frequency of 1.99 GHz for MSTL and MTM sensor with nine unit cells, respectively. MTM sensors with an increasing number of cells show higher sensitivity of 0.62° per mmol/L and unit cell to blood glucose concentration as measured by changes in ∠S21. In accordance with the numerical simulations, the MTM sensor with nine unit cells showed the highest sensitivity of the sensors proposed by us, with an average of 3.66° per mmol/L at a frequency of 1.99 GHz, compared to only 0.48° per mmol/L for the MSTL sensor. The multi-cell MTM sensor has the potential to proceed with evaluation of human blood samples.


2020 ◽  
Vol 77 (10) ◽  
pp. 739-744
Author(s):  
Julia D Muzzy Williamson ◽  
Brenda Thurlow ◽  
Mohamed W Mohamed ◽  
Dacotah Yokom ◽  
Luis Casas

Abstract Purpose Successful use of a subcutaneous insulin pump to administer regular insulin to a preterm infant with neonatal hyperglycemia is described. Summary A 520-g female infant born at 23 weeks’ gestational age via caesarian section was noted to have elevated blood glucose concentrations ranging up to 180 mg/dL (in SI units, 10 mmol/L) on day of life (DOL) 3 and peaking on DOL 9 at 250 mg/dL (13.9 mmol/L) despite conservative glucose infusion rates. Continuous infusion of regular insulin was begun on DOL 8 and continued through DOL 44, with an average insulin infusion rate of 0.08 units/kg/h. The patient experienced blood glucose concentration lability due to multiple factors, resulting in the need for frequent and routine blood glucose concentration monitoring to minimize hypoglycemia events. On DOL 44, a subcutaneous insulin pump was placed and used to provide diluted regular insulin (25 units/mL). After 1 week, the patient’s blood glucose concentration normalized, which led to a reduction in the frequency of glucose monitoring. After 3 weeks, insulin pump use was discontinued. The patient remained euglycemic thereafter. Conclusion The use of an insulin pump resulted in decreased blood glucose checks, discontinuation of central line access, and overall better patient care.


2019 ◽  
Vol 10 (12) ◽  
pp. 783-792 ◽  
Author(s):  
Scott Pardo ◽  
Nancy Dunne ◽  
David A Simmons

Aim: The radar plot is a relatively new way of communicating blood glucose monitoring system (BGMS) accuracy and precision: data points positioned within concentric circles represent the magnitude (increasing with distance from center) and direction (relative to horizontal) of BGMS-error (center = equivalency with reference instrument measurement). This manuscript aims to demonstrate the utility of radar plots as visual tools for interpretation of BGMS analytical performance. Results & methodology: Radar plots were constructed for five BGMSs, to compare BGMS blood glucose results with reference instrument measurements. Conclusion: Radar plots are a useful tool for the visualization of BGMS analytical performance, communicating accuracy, precision and the satisfaction of certain regulatory criteria at a glance.


2015 ◽  
Vol 11 (5) ◽  
pp. 20150208 ◽  
Author(s):  
Carsten Schradin ◽  
Neville Pillay ◽  
Anna Kondratyeva ◽  
Chi-Hang Yuen ◽  
Ivana Schoepf ◽  
...  

Vertebrates obtain most of their energy through food, which they store mainly as body fat or glycogen, with glucose being the main energy source circulating in the blood. Basal blood glucose concentration (bBGC) is expected to remain in a narrow homeostatic range. We studied the extent to which bBGC in free-living African striped mice ( Rhabdomys pumilio ) is influenced by ecological factors with a bearing on energy regulation, i.e. food availability, abiotic environmental variation and social tactic. Striped mice typically form extended family groups that huddle together at night, reducing energetic costs of thermoregulation, but solitary individuals also occur in the population. We analysed 2827 blood samples from 1008 individuals of seven different social categories that experienced considerable variation in food supply and abiotic condition. Blood samples were taken from mice in the morning after the overnight fast and before foraging. bBGC increased significantly with food plant abundance and decreased significantly with minimum daily ambient temperature. Solitary striped mice had significantly higher bBGC than group-living striped mice. Our results suggest that adaptive responses of bBGC occur and we found large natural variation, indicating that bBGC spans a far greater homeostatic range than previously thought.


1993 ◽  
Vol 47 (7) ◽  
pp. 875-881 ◽  
Author(s):  
R. Marbach ◽  
Th. Koschinsky ◽  
F. A. Gries ◽  
H. M. Heise

Near-infrared (NIR) spectra of the human inner lip were obtained by using a special optimized accessory for diffuse reflectance measurements. The partial-least squares (PLS) multivariate calibration algorithm was applied for linear regression of the spectral data between 9000 and 5500 cm−1 (Λ = 1.1–1.8 μm) against blood glucose concentrations determined by a standard clinical enzymatic method. Calibration experiments with a single person were carried out under varying conditions, as well as with a population of 133 different patients, with capillary and venous blood glucose concentration values provided. A genuine correlation between the blood glucose concentrations and the NIR-spectra can be proven. A time lag of about 10 min for the glucose concentration in the spectroscopically probed tissue volume vs. the capillary concentration can be estimated. Mean-square prediction errors obtained by cross-validation were in the range of 45 to 55 mg/dL. An analysis of different variance factors showed that the major contribution to the average prediction uncertainty was due to the reduced measurement reproducibility, i.e., variations in lip position and contact pressure. The results demonstrate the feasibility of using diffuse reflectance NIR-spectroscopy for the noninvasive measurement of blood glucose.


Author(s):  
Kanimozhi R ◽  
Saravanakumar S

Diabetes Mellitus is a serious and chronic health disease. It occurs in all age group of people, especially in adults and aged persons. It is important to measure blood glucose level frequently for the diabetes affected persons which in need to determine the appropriate insulin dosage. Along with this, the continuous glucose monitoring is vital to know whether the glucose level is in normal range. The conventional method used to measure the glucose level in blood is invasive which is infectious and a painful process. Nowadays, the non-invasive blood glucose monitoring methods are widely used. In this work, the blood glucose level is measured non-invasively using IR sensor. Besides that, the indication of insulin dosage to be taken is done by determining blood glucose concentration (non- invasively) and comparing it with Body Mass Index (BMI) of the patient. The implementation is based on the variations in the intensity of the IR LED, BMI and blood density. Themethod ismore reliable than the invasive techniques.


2019 ◽  
Vol 104 (11) ◽  
pp. 5217-5224 ◽  
Author(s):  
Saeed Reza Toghi-Eshghi ◽  
Jane E Yardley

Abstract Objective To determine the effect of morning exercise in the fasting condition vs afternoon exercise on blood glucose responses to resistance exercise (RE). Research Design and Methods For this randomized crossover design, 12 participants with type 1 diabetes mellitus [nine females; aged 31 ± 8.9 years; diabetes duration, 19.1 ± 8.3 years; HbA1c, 7.4% ± 0.8% (57.4 ± 8.5 mmol/mol)] performed ∼40 minutes of RE (three sets of eight repetitions, seven exercises, at the individual’s predetermined eight repetition maximum) at either 7 am (fasting) or 5 pm. Sessions were performed at least 48 hours apart. Venous blood samples were collected immediately preexercise, immediately postexercise, and 60 minutes postexercise. Interstitial glucose was monitored overnight postexercise by continuous glucose monitoring (CGM). Results Data are presented as mean ± SD. Blood glucose rose during fasting morning exercise (9.5 ± 3.0 to 10.4 ± 3.0 mmol/L), whereas it declined with afternoon exercise (8.2 ± 2.5 to 7.4 ± 2.6 mmol/L; P = 0.031 for time-by-treatment interaction). Sixty minutes postexercise, blood glucose concentration was significantly higher after fasting morning exercise than after afternoon exercise (10.9 ± 3.2 vs 7.9 ± 2.9 mmol/L; P = 0.019). CGM data indicated more glucose variability (2.7 ± 1.1 vs 2.0 ± 0.7 mmol/L; P = 0.019) and more frequent hyperglycemia (12 events vs five events; P = 0.025) after morning RE than after afternoon RE. Conclusions Compared with afternoon RE, morning (fasting) RE was associated with distinctly different blood glucose responses and postexercise profiles.


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