A SENSOR FOR MEASURING THE OXYGEN SATURATION OF EPIDURAL AND METHOD FOR SENSING THE OXYGEN SATURATION OF EPIDURAL

摘要

A sensor for measuring oxygen saturation of blood in a skull is disclosed. The sensor of the first embodiment includes a photo detector and a pair of light emitting diodes mounted at the ends of an integrated fusible print wire. The sensor is sealed by a rubber or polymer material having a light window on the light detector and the light emitting diode. The sensor is inserted through a drilled hole in the skull and slides between the skull and the dura of the cerebrum. The light emitting diode is pulsed to illuminate the blood in the dura mater and cerebrum with light, and the light reflected by the blood is received by the photo detector and converted into an electrical signal. The signal is processed by a pulse densitometer to indicate blood saturation. In a second embodiment, the photodetector and light emitting diode are mounted to the bottom of a core of compressible foam material extending from the end of a hollow bone screw. When the screw is clamped into the skull, the photodetector and light emitting diode are in contact with the dura mater, and the foam material is compressed to maintain the optical contact between the electrical element and the dura mater. Light from the diode is reflected from the blood in the dura mater and cerebrum and received by a light detector, so that the resulting electrical signal is processed by a pulse densitometer.