Abnormal arterial physiology Inaccurate finger pulse oximetry oxygen saturation measurement 2025-03-09T11:22:14Z Pulse oximetry is an useful, readily available and non-invasive tool of measuring oxygen saturation. It uses light sensors containing two light sources of different wavelengths, that are absorbed by haemoglobin (both oxy and deoxy forms) and transmitted through tissues to a photodetector. Any discrepancy in the light transmission caused either by vascular abnormality of the fingers or anatomical change may lead to inaccurate or absence of reading in the pulse oximeter. Any substantial discrepancy between the measurement of oxygen saturation with finger probe pulse oximetry as compared to an arterial blood gas, which is considered the gold standard.