The oximeter that includes both Plethysmograph and Perfusion Index (PI) in one device. Determine the optimal time to take a reading. Eliminate second guessing if readings are accurate and reliable.
Each wave corresponds to a heartbeat and the amplitude to the amount of blood detected in your blood vessels. When the wave amplitude is consistent (as shown in the figure), the pulse oximeter is optimized and readings can be taken.
The Perfusion Index (PI) conveniently informs you of the strength of your pulse. If the PI value is less than 0.2%, this means that your hands are either too cold or improperly positioned in the pulse oximeter. Simply warm your finger and reposition it so that it is right between the LED light and sensor. No more second guessing if the readings are reliable or why the pulse oximeter is not giving a reading.