Automated Near-Continuous Glucose Monitoring Measured in Plasma Using Mid-Infrared Spectroscopy

Abstract

There are increasing calls for a precise, automated system to enable tight glycemic control and to avoid hypoglycemia in an intensive care unit setting. OptiScan Biomedical has developed a glucose monitor based on mid-infrared spectroscopy that withdraws blood samples (120 µl) and measures plasma glucose. The goal of this study was to validate the performance of the OptiScan Model 5000 over a wide range of glycemic levels in patients. Research Design and Methods: Sixty people with type 1 (n = 18) or type 2 (n = 42) diabetes who were otherwise healthy were connected to OptiScanners. Their blood glucose concentrations were kept in a euglycemic, hypoglycemic (<75 mg/dl), and hyperglycemic (>180 mg/dl) range by intravenous administrations of insulin and glucose. OptiScanner venous blood samples were automatically withdrawn every 15 minutes. Reference measurements were done using the YSI 2300 glucose analyzer. Results: The aggregate data points (1155 paired readings) were within International Organization for Standardization standards, with 98.6% of the glucose values within ±20% above 75 mg/dl and ±15 mg/dl below this value. A Clarke error grid analysis showed a total of 1139 points (98.6%) in zone A. Points outside of A exceeded the A zone boundary by an average of 4.3%. The r 2 was 0.99. The total coefficient for variance was 6.4%. Conclusions: These results show that the OptiScanner is highly accurate in healthy patients with diabetes across a wide range of glucose values. Mid-infrared spectroscopy may become the method of choice for highly accurate, high frequency, automated glucose measurements and may thus enable better glycemic control in critically ill patients.

Manual versus Automated moNitoring Accuracy of GlucosE II (MANAGE II)

“…These findings are consistent with results published in a former validation study performed with the same device over shorter periods in 71 patients [19], and with the legal requirements of regulatory agencies (CEG zones A + B > 99%). Good correlation between blood glucose values obtained from the OptiScanner® and those obtained using a reference method has also been reported in vivo in an animal study [20], in patients with diabetes [21] and in critically ill patients [19, 22, 23]. CEG analysis and other techniques, such as the Bland–Altman method, have been used to assess discrete point-of-care measurement technologies for a considerable period of time.…”

U-shaped fiber-optic ATR sensor enhanced by silver nanoparticles for continuous glucose monitoring

“…However, the absorption spectrum of urea, urea acid, creatinine, phosphate and other materials in blood or interstitial fluid overlapped with the glucose absorption spectrum (Jax et al, 2011;Martin et al, 2005), which is the biggest challenge for glucose monitoring using spectral method, especially for single or two wavelengths spectrometer. Therefore, at least 3-5 working wavelengths were needed to overcome the spectral interference presented by other substances and achieve high-precision glucose monitoring from ISF using spectral analysis (Pleitez et al, 2012;Vrančić et al, 2011).…”

Real-Time Monitoring of Critical Care Analytes in the Bloodstream with Chemical Sensors: Progress and Challenges

“…Several companies have pursued developing clinical products that utilize these ex vivo patient attached sensor or sensor array approaches (86) such as Via R Blood (Via Medical Corporation, Austin, TX) (87), STG-22 TM (Nikkiso, Tokyo, Japan) (88), OPTImus (IntelliDx Corporation, Santa Clara, CA) (89), OptiScanner 5000 (Optiscan Biomedical Corporation, Hayward, CA) (90,91), and GlucoScout (International Biomedical, Corporation, Austin, TX) (http://www.intbio.com/continuous-blood-monitoring.php?productsubcategory=blood-glucose) for detecting blood gases, electrolytes, and glucose. Although the potential for achieving more accurate results using this approach is clear cut, given these systems operate more akin to sensor-based in vitro whole blood analyzers, there are some key regulatory hurdles to overcome.…”