title: Two-wavelength carbon dioxide laser application for in-vitro blood glucose measurements.
abstract: To develop a fast and easy clinical method for glucose measurements on whole blood samples, changes in glucose spectra are investigated varying temperature, glucose concentration, and solvent using attenuated total reflection Fourier transform infrared (ATR- FTIR) measurements. The results show a stability of the spectra at different temperatures and wavelength shifts of the absorption bands when water is replaced by blood. Because the ATR measurements are influenced by sedimentation of the red blood cells, a two-wavelength CO2 laser is used to determine the glucose concentration in whole blood samples. For this purpose, the first laser wavelength lambda(1) is tuned to the maximum of the glucose absorption band in blood at 1080 cm(-1), and the second laser wavelength lambda 2 is tuned to 950 cm(-1) for background measurements. The transmitted laser power through the optical cell containing the whole blood sample at lambda 1 and lambda 2 is used to determine the ratio. This signal correlates well with the glucose concentration in the whole blood samples. The CO2 laser measurement is too fast to be influenced by the red blood cell sedimentation, and will be a suitable method for glucose determination in whole blood.
authors.affiliation: Charité - Universitätsmedizin Berlin, Institut für Medizinische Physik und Lasermedizin, Berlin, Germany. martina.meinke@charite.de
authors.forename: Martina
authors.initials: M
authors.lastname: Meinke
authors.forename: Gehard
authors.initials: G
authors.lastname: Müller
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Albrecht
authors.forename: Christina
authors.initials: C
authors.lastname: Antoniou
authors.forename: Heike
authors.initials: H
authors.lastname: Richter
authors.forename: Juergen
authors.initials: J
authors.lastname: Lademann
mesh_terms: D001774:Blood Chemical Analysis / Q000295:instrumentation* / Q000379:methods; D001786:Blood Glucose / Q000032:analysis*; D002245:Carbon Dioxide; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007834:Lasers; D010783:Photometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation* / Q000379:methods
chemical_list: D001786:Blood Glucose; D002245:Carbon Dioxide