The measurement of oxygen saturation in arterial and venous blood

Non-invasive optical measurement techniques are described which are used to assess oxygen saturation in arterial and venous blood. The most important aspect of a certain technique is within its optical measurement of the percentage of oxygenated hemoglobin which is then called the oxygen saturation. Its value in the arteries is related to the adequacy of the respiratory system while its value in the veins is related to the amount of blood flow to the tissue. When measurement techniques uses two wavelengths in the infrared, it enables the use of pulse oximetry without calibration.