title: In vivo evaluation of a chip based near infrared sensor for continuous glucose monitoring.
abstract: In this paper we describe the concept and in vivo results of a minimally invasive, chip-based near infrared (NIR) sensor, combined with microdialysis, for continuous glucose monitoring. The sensor principle is based on difference absorption spectroscopy in selected wavelength bands of the near infrared spectrum (1300 nm, 1450 nm, and 1550 nm) in the 1st overtone band. In vitro measurements revealed a linear relationship between glucose concentration and the integrated difference spectroscopy signal with a coefficient of determination of 99% in the concentration range of 0-400mg/dl. The absolute error in this case is about 5mg/dl, corresponding to a relative error of about 5% for glucose concentrations larger than 50mg/dl and about 12% in the hypoglycemic range (<50mg/dl). In vivo measurements on 10 patients showed that the NIR-CGM sensor data reflects the blood reference values adequately, if a proper calibration and a signal drift correction is applied. The mean MARE (mean absolute relative error) value taken over all patient data is 13.8%. The best achieved MARE value is at 4.8%, whereas the worst lies at 25.8%, leading to a standard deviation of 5.5%.
authors.affiliation: Institut fuer Mikrotechnik Mainz GmbH, Microstructuring and Sensors Department, Carl-Zeiss-Strasse 18-20, D-55129 Mainz, Germany. Electronic address: benmohammadi@imm-mainz.de.
authors.forename: Lhoucine
authors.initials: L
authors.lastname: Ben Mohammadi
authors.forename: Thomas
authors.initials: T
authors.lastname: Klotzbuecher
authors.forename: Susanne
authors.initials: S
authors.lastname: Sigloch
authors.forename: Knut
authors.initials: K
authors.lastname: Welzel
authors.forename: Michael
authors.initials: M
authors.lastname: Göddel
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Pieber
authors.forename: Lukas
authors.initials: L
authors.lastname: Schaupp
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001786:Blood Glucose / Q000737:chemistry / Q000302:isolation & purification*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D006801:Humans; D017551:Microdialysis; D018670:Monitoring, Ambulatory; D019265:Spectroscopy, Near-Infrared
chemical_list: D001786:Blood Glucose
keywords: Continuous glucose monitoring; Diabetes; Microdialysis; Near infrared difference spectroscopy