title: Automated near-continuous glucose monitoring measured in plasma using mid-infrared spectroscopy.
abstract: OBJECTIVE
  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.
  
  
  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 OptiScanner venous blood samples were automatically withdrawn every 15 minutes.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.
authors.affiliation: Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jax
authors.forename: Tim
authors.initials: T
authors.lastname: Heise
authors.forename: Leszek
authors.initials: L
authors.lastname: Nosek
authors.forename: Jennifer
authors.initials: J
authors.lastname: Gable
authors.forename: Gene
authors.initials: G
authors.lastname: Lim
authors.forename: Christopher
authors.initials: C
authors.lastname: Calentine
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001331:Automation; D001786:Blood Glucose / Q000378:metabolism; D015190:Blood Glucose Self-Monitoring / Q000379:methods*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004867:Equipment Design; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000175:diagnosis; D007003:Hypoglycemia / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D012107:Research Design; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D001786:Blood Glucose