Explainer | How does an oxygen concentrator help?

The device can aid those whose oxygen saturation levels are between 88 and 92 by reducing the burden on the lungs.

VISAKHAPATNAM, 13/09/2008: A constable inhaling enriched oxygen from the oxygen concentrator, requisitioned by the city police for the first time in AP Police for the benefit of constables who are exposed to vehicular emissions, dust and pollution for eight to 10 hours at a stretch, in Visakhapatnam on September 13, 2008. Many of constables, particularly those posted in high pollution zones like the industrial belt and old town are forced to breathe polluted air for long periods and are susceptible to respiratory and other diseases. The oxygen concentrators, manufactured by AirSep Corp, USA, will help the constables to fight the fatigue and stress caused by air pollution. Traffic constables can inhale fresh oxygen after duty for the time recommended by doctors to neutralise the ill-effects of breathing polluted air. Photo: C.V. Subrahmanyam

With the demand for medical oxygen continuing unabated and several States struggling to keep pace with demand, the oxygen concentrator has emerged as a sought after device. Unlike medical oxygen sourced from industrial units, which are supplied via cylinders, concentrators are devices that can be operated at home.

When is an oxygen concentrator needed?

When blood saturation levels drop below 94%, it could be a sign of respiratory distress. Usually this merits hospitalisation, but due to the surge in COVID-19 cases and oxygen beds in short supply, the device could help those whose saturation levels range between 88-92 if they can’t access hospital services. Any lower would require more intensive oxygenation and any higher would mean that an improvement in lung function can obviate the need for such a device.

What does a concentrator do?

An oxygen concentrator takes in air and separates the oxygen and delivers it into a person via a nasal cannula. Air is 79% nitrogen and 21% oxygen and a concentrator that works by plugging into a source of electricity delivers air that is upto 95% oxygen. In respiratory infections that causes oxygen saturation levels to dip below 90%, having an external device supply pure oxygen eases the burden on the lungs. However in cases of severe respiratory distress, it may be necessary to provide oxygen that is almost 99% pure and a oxygen concentrator is not up to that job.

How does it work?

A concentrator consists of a compressor and sieve bed filter. The former squeezes atmospheric air and also adjusts the pressure at which is delivered. The sieve bed is made of a material called Zeolite that separates the nitrogen. There are two sieve beds that work to both release oxygen into a tank that’s connected to the cannula as well as release the separated nitrogen and form a continuous loop that keeps producing fresh oxygen.

Are all concentrators the same?

These products come with a variety of specifications. There are those with varying oxygen outputs. For COVID-19 patients, a device with a 5L-10 L output is recommended. What’s important though is that it delivers air that contains at least 90% pure oxygen. The cost of these devices can range from ₹40,000-₹90,000. There are also pulse and continuous flow concentrators where the latter delivers oxygen at a constant rate and the other uses a sensor to deliver a puff of oxygen when a user is about to inhale.