The Measurement Principle of Normal Pulse Oximeter
Dec 20, 2023
Blood Pressure Watch
➤The oximeter has a light source that emits two wavelengths of light, and HbO2 and Hb have different light absorptions for these two wavelengths.
➤ When the arterial pulses, the blood volume at the measurement site will change, forming a certain waveform. The SpO2 is calculated by the oximeter according to the waveform and absorption rate.
➤ In addition to arteries, veins and surrounding soft tissues also absorb light waves from the illuminator, which is "background noise" for arterial oxygen.
➤ However, the pulsatility of the vein is very weak, and the absorption of light intensity by the vein and surrounding soft tissue can be regarded as a constant value.
➤The arteries have obvious pulsatility, the light intensity received by the opposite receiver will change periodically with the pulsation of the arteries, and the oximeter can determine which light intensities are absorbed by Hb and HbO2 in the arteries , so as to calculate SpO2 through the formula.
➤ When measuring, try to choose parts with thinner soft tissue and richer arterial blood flow, such as hands, toes, and earlobes.
There you can have a look of BP doctor watch to measure and monitor your blood pressure.