A. BRADU*, CECILLE JULIEN**, EMANUELLE GRILLON**, J.F. PAYEN**, J. DEROUARD***

*Physics Faculty, “Alexandru Ioan Cuza” University, 11A, Carol I Blvd, 700506-Iaşi, Romania
**Unite Mixte INSERM/UJF 594, LRC CEA 30V, Hopital Michalon, Grenoble, France
***Laboratoire de Spectrométrie Physique, UMR CNRS 5588, “Joseph Fourier” University, Grenoble, France

Abstract. In this work, the overall results on the feasibility of realizing in vivo local oxygenation measurements using a spectroscopic technique are reported. In order to achieve in vivo, local monitoring of hemoglobin oxygen saturation, optical fiber probes were inserted into the rat striatum. The probes consisted of two optical multimode fibers stack together. One fiber was used to illuminate the medium by means of a halogen stabilized white lamp while the other one was used to collect the reflected light and direct it to a grating spectrometer equipped with a cooled CCD camera. By measuring the reflectance spectra the chromophores concentrations and hemoglobin oxygen saturation were calculated during different experimental protocols while progressive hypoxia episodes were performed by artificial ventilation with different mixtures of oxygen and nitrogen. Our results proved that our technique provides feasible results on the temporal variations of some physiological parameters such as hemoglobin and sufficiently sensitive to distinguish various hemodynamic effects such as tracking an optical bolus, to detect a cerebral ischemia and to observe effects such as variations in the redox state of the respiratory enzymes.

Corresponding author’s e-mail: a.bradu@kent.ac.uk

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