TRANSCRANIAL OPTICAL SPECTROSCOPY - A COMPARISON OF THE TOS-96 AND INVOS-3100 CEREBRAL OXIMETERS

We evaluated two user-friendly, commercially available transcranial ce rebral oximeters (TOS 96, Tostec, Tokyo, Japan and INVOS 3100, Somanet ics, Troy, USA) for use in adults. We compared the absolute values (%) of regional cerebral oxygen saturation (rSO(2)) from 108 measurements in 54 healthy volunteers (31 women, mean age 35.8 +/- 16.3 years and 23 men, mean age 35.4 +/- 9.2 years). The mean rSO(2) values obtained by the TOS 96 and INVOS 3100 systems were 72.3 +/- 8.4 % and 72.6 +/- 7.2 % respectively. Significant differences (p < 0.01) were found betw een females and males with the INVOS equipment. The study shows that a natomical (thickness of the skull) and technical (calibration) aspects have to be taken into consideration when interpreting absolute rSO(2) values.