Mindray iPM-9800, Operator'S Manual

Page: 111 / 300

11-1
11
Monitoring SpO
2
11.1 Introduction
SpO
2
monitoring is a non-invasive technique used to measure the amount of oxygenated
haemoglobin and pulse rate by measuring the absorption of selected wavelengths of light.
The light generated in the probe passes through the tissue and is converted into electrical
signals by the photodetector in the probe. The SpO
2
module processes the electrical signal
and displays a waveform and digital values for SpO
2
and pulse rate. This device is calibrated
to display functional oxygen saturation. It provides four measurements:
1. Pleth waveform (Pleth): visual indication of patient’s pulse. The waveform is
normalized.
2. Oxygen saturation of arterial blood (SpO
2
): percentage of oxygenated hemoglobin in
relation to the sum of oxyhemoglobin and deoxyhemoglobin.
3. Perfusion indicator: the pulsatile portion of the measured signal caused by arterial
pulsation.
4. Pulse rate (derived from pleth wave): detected pulsations per minute.
4 2
1
3