Oxygen saturation of arterial blood flow

The BBC News published an article which discusses the benefits of new technology which will allow doctors to measure blood pressure from arterial blood flow through the aorta. Arterial blood flow is more important than other types of blood flow (such as deoxygenated vascular blood returning back to the heart) because it has been freshly pumped straight from the heart; this means that it gives a much more accurate picture of blood pressure actually at the heart (and therefore a more accurate picture of your risk of heart disease). This also means, in the case of sp02 measurement, that this recently oxygenated arterial blood can be an accurate indicator of lung function.

All the fingertip pulse oximeters and handheld pulse oximeters at FingerOnPulse.Com measure the pulse rate and sp02 from arterial blood only. The oximeters can cleverly distinguish between arterial blood and other interference (venous blood, bone, muscle, fat and even fingernail polish) by looking out for the tell-tale pulsing rhythm of the arterial blood, as it is pumped straight out from the heart.

When it comes to sp02 measurement, high-quality oximeters look for the differences in absorbance of red and infrared light, caused by the difference in colour between oxygen-bound (bright red) and oxygen-unbound (dark red or even blue) haemoglobin. The percent of haemoglobin molecules bound with oxygen molecules is your oxygenation reading.