How do POCs work?

How do Portable Oxygen Concentrators work?

Have you ever asked yourself ‘how does a portable oxygen concentrator work?’ Over the last 15 years these small and lightweight devices have replaced the once cumbersome task of relying on tank oxygen for a patients reliant on O2. Today portable oxygen concentrators weigh around 2kg, can be easily carried onto commercial flights and have opened up a whole new world of opportunities for sufferers of COPD.

An glimpse at Oxygen Therapy in 1903.

Oxygen Therapy in 1903.

Before we break down the process of how a portable oxygen concentrator works it’s a good idea to have an appreciation for the history of oxygen therapy. Oxygen Therapy has its roots in the great leaps made within the field of chemistry during the 18th century. When Oxygen was first discovered it quickly became evident that it could have a positive medical use. During the 19th century therapeutic oxygen use entered the mainstream, however this was more experimental and not something accessible to the average person.

Fast forward to the 20th century and oxygen therapy had become an effective and accessible treatment for many medical conditions. Trials and tests were being conducted to determine optimum dosage and delivery techniques. During this period home administration of Oxygen begins to become economical and within the reach of most people. Firstly through the use of oxygen filled tanks, which needed constant refilling and replacement, and eventually to floor-standing oxygen concentrators. These new devices removed the requirement for a constant oxygen tank deliveries, a great improvement, however the units were large and needed to be plugged into mains power to function.

Enter the new millennium and companies like Inogen began releasing portable oxygen concentrators. These new devices were powered by batteries and light enough that they could be carried easily by a user. Today these devices have become affordable, portable and reliable.


How a portable oxygen concentrator works.

While it might sound technical an oxygen concentrator is really quite a simple device. They operate on the principle of ‘rapid pressure swing adsorption’ of atmospheric nitrogen onto specific minerals and then venting the nitrogen. As air is made up of 77% Nitrogen and 20% Oxygen what this process does is separate Nitrogen from regular air and pump the remaining mixture of gas to the user. This gas mixture is primarily oxygen, however other gasses are also present such as argon and CO2.

Pictured at the start of this post is a photo of the inside of an Inogen One G3 Oxygen concentrator. To the left of the image you will notice a pair of tall cylinders (one of them is slightly hidden behind the other). These two cylinders are filled with ‘zeolite pellets’, atmospheric air is pumped into the first of these chambers where the process of separating Nitrogen is undertaken. This first chamber then pumps its contents into the second cylinder for further refinement. The pressure in the hose delivering oxygen from the second cylinder (also called a tank) is kept steady by a pressure reducing valve. Other components include an air compressor, air filter and control board.


The future is bright for oxygen therapy.

A bright future for oxygen therapy.

The future of portable oxygen therapy.

The next decade promises to be an exciting period for oxygen therapy. We can expect to see the size and portability of oxygen devices improve as well as having them come down in cost. As new battery technologies are adopted you will be able to travel for longer periods between charges.

We still believe that prevention is better then treatment, as most cases of COPD are caused by environmental or lifestyle factors identifying and addressing these first should be the priority for those in high risk.