Retinal pulse oximetry: Towards a method for measuring cerebral oxygen saturation
Scott VA., Tarassenko L., Glynn CJ., Hill AR.
An instrument to make reflectance pulse oximetry measurements on the blood in the retinal fundus has been developed. Conventional pulse oximeters measure the oxygen saturation of arterial blood in the peripheral circulation, whereas using the retina provides the opportunity to monitor cerebral oxygenation. Cardiac-synchronous pulsations have been observed in the red and IR signals during preliminary in vivo trials, however it is unclear whether these pulsations are entirely due to the pulsating volume of arterial blood. Analysis of a series of retinal images has revealed that pulsations can be detected from the veins and choroidal background as well as from the arteries.