Measurements of cerebral arterial oxygen saturation using a fiber-optic pulse oximeter

This pilot investigation was undertaken to assess the performance of a novel fiber-optic cerebral pulse oximetry system. A fiber-optic probe designed to pass through the lumen of a cranial bolt of the type used to make intracranial pressure measurements was used to obtain optical reflectance signals directly from the brain tissue. Preliminary results from seven patients measured in the operating theatre and ITU are presented. Estimations of cerebral arterial oxygen saturation derived from a frequency domain-based algorithm are compared with pulse oximetry (SpO₂) and hemoximeter (SaO₂) blood samples. The mean (plusmnSD) difference between cerebral oxygen saturation (ScaO₂) and finger SpO₂ (in saturation units) was -7.47(plusmn3 .4)%. The mean (plusmnSD) difference between ScaO₂ and blood SaO₂ was -7.37(plusmn2.8)%.