What is a Pulse Oximeter?

A Pulse Oximeter is a device that is used to quickly and easily monitor a person’s oxygen saturation.

This means that is can measure the level of oxygen within the blood, specifically in arterial blood without using any invasive means.

What Does a Pulse Oximeter Measure?

Pulse Oximeters measure the percentage of arterial oxygen primarily. In more precise terms, this is the amount of oxygen carried on blood hemoglobin.

It’s known as SpO2. Heart rate (HR) is automatically calculated alongside the percentage of oxygen. HR and SpO2 complement one another, and clinicians find this double parameter readout quite informative.


How Does a Pulse Oximeter Work?

Pulse oximeters work on a simple but brilliant principle. Blood absorbs light, and there’s a distinct difference between the wavelengths that go through oxygenated and de-oxygenated blood.

The finger clip of a pulse oximeter consists of a transmitting light source that emits a broad spectrum of light. On the other end, there’s a receiver that measures how much light passes through. The diode on the receiving end is capable of detecting the wavelength of light.

The internal circuits and processing components of the pulse oximeter do some calculations as well. The device has to compensate for the ambient light, finger size, and the absorbance of the rest of the tissues.

There’s a reference curve saved in the memory of the device to calibrate the incoming readings and normalize them. This increases the precision of the results that it provides.