Pulse Oximeters : Part 1

What is Oximetry?

Oximetry is a simple non invasive medical procedure used to measure the concentration of oxygen in the blood. Oximetry is widely used in the hospital care setting to assess patients who have a variety of lung and heart disorders. The measurement of oxygen is done by an oximeter which is a photoelectric device. The majority of Oximeters are small, portable and reusable. Many home devices can be run on batteries.

Where is a pulse oximeter placed on the body?

The oximeter can be placed on the finger tip, ear lobe or toes. Pulse Oximeters are so called because they react only to pulsations of the blood vessels. If there is no pulse, Oximeters will not pick up the pulsations and oxygen concentration cannot be obtained.

Pulse Oximeters are used in all intensive care units, the neonatal unit, coronary care unit, emergency room and during anesthesia. Portable Oximeters are now widely used on the regular medical floors in hospitals across America. The majority of patients who have emphysema, COPD or congestive heart failure are monitored by pulse Oximetry in the hospital.

How does a pulse oximeter work?

The pulse Oximeters work by transmitting a beam of red and infrared light though a pulsating blood vessel. The ratio of red to infra red blood light transmitted provides a measure of the oxygen saturation of the blood. The oximeter identifies the pulse and then deducts the intensity of color perceived when the pulse is absent. The residual intensity of color corresponds to only the oxygenated red blood. This is shown on the electronic screen as a percentage of oxygen saturation in the blood.