A first embodiment of an oximetry probe is attached around a blood vessel near the site of a likely stroke. That will be useful to monitor large and medium size cerebral arteries. Another type of pulse oximeter can be passed within cerebral blood vessels to monitor the oxygenation status of the surrounding cerebral tissues. In that version, the emitter and detector are coplanar and contained in a small area, e.g., 50-12 μm.
