Contact lens oximetry: a valid concept?

Although it has been shown that the technique of contact lens pulse oximetry has severe limitations, the authors' imaging study showed that the technology now exists with which to develop a compact imaging system which could perform oximetry on the blood in the retinal fundus. Individual vessels could be segmented from the images in order to determine blood oxygen saturation in either arteries or veins. This would provide valuable information for an anaesthetist during surgery and would neatly circumvent one of the main limitations of pulse oximetry, namely the need to detect a pulse before analysis can begin. Perhaps most importantly, this instrument could be used with cardiac patients in the hope that it would significantly improve their level of care in the operating theatre.