11. REFERENCE
Measurement Principle
Oxygen Saturation Monitor PULSOX-2 is a photometric instrument that non-invasively and continuously measures the oxyhemoglobin saturation of arterial blood (SpO2) and the pulse rate. SpO2 is described by the equation:
| SpO2 = | C (HbO2) | ⋅ 100 (% SpO2) |
| C (HbO2) + C (Hb) |
| | |
| where | | |
| C (Hb): | Concentration of reduced hemoglobin |
C (HbO2): Concentration of oxyhemoglobin
The light-absorption characteristics of reduced hemoglobin (Hb) are very different from those of oxyhemoglobin. The PULSOX-2 measures the changes in the absorption of red and infrared lights passing through the tissue to determine the SpO2 of the blood. Thus, this method is free from the effects of skin color, muscles, bones, and veins.
Spectral Absorption of Hb and HbO2
⋅10 -6cm2 mole
1.0
coefficient | |
Absorption | 0.5 |
