What is the waveform display?

Some more advanced fingertip pulse oximeters boast waveform displays as one of their features – but what is really going on?

Pulse Oximeters differentiate between the light absorbed by the oxygenated arterial blood (what it wants to measure), and other interference (light absorbed by veins, skin and bone, for example).

The difference between arterial blood and other blood is that arterial blood is pumped by the heart, pulsing and fading with each heartbeat.

Oximeters subtract trough from peak levels, and the difference is the light absorbed only by the arterial blood. These troughs and peaks are what are being displayed in graphical format on your fingertip pulse oximeter with waveform display capability.