Published on : 23 May 20194 min reading time

This is one of the most common questions among those asked by patients. The answer is not simple, but you will discover it at the end of the article.

Oxygen emission modalities

The main difference between the portable oxygen concentrator and the liquid oxygen cylinder is the type of emission. The concentrator emits oxygen only when the patient is in inspiration phase, while nothing is emitted when the patient is in the exhalation phase. This type of discontinuous emission is called “pulsed wave” or “on demand” ..

On the contrary, the oxygen cylinder emits oxygen in a continuous flow: both in the inspiration phase and in the expiration phase, it emits oxygen. This is why most of the oxygen in the bottle (indicative 3/4 of the content) is issued without any use, which is certainly a great waste in times of crisis.

Rehabilitation function of portable oxygen concentrators

It is precisely thanks to their type of emission that the portable concentrators allow a greater reeducation – and therefore a general improvement – of the respiratory system. Oxygen is only emitted through a nasal cannula and only in inspiration phase, the patient will not be able to use the mouth in compensation to oxygenate the lungs. On the contrary, with liquid oxygen in the bottle, it is possible to breathe the open mouth, thanks to the flow of excess oxygen that leaves on the face, both with the nasal cannula and the facial mask.

Although it may seem strange, forcing oneself to breathe as much as possible only with the nose makes it possible to obtain a more efficient breathing and therefore a better saturation of oxygen in the blood: it is not uncommon for some patients from liquid oxygen to a portable oxygen concentrator can reduce oxygen input by at least 1 or 2 liters / min.

The fear of staying without oxygen

One of the biggest fears of those who use oxygen therapy is to stay without oxygen: the bottle empties regularly and needs a continuous refill / replacement service to guarantee the patient’s treatment. Often, the service of those who bring home oxygen is not so effective and so patients live in perpetual anxiety of not getting their oxygen on time and staying short. In addition, the fear of remaining oxygen-free when walking with the stroller (the portable bottle) is even greater: its autonomy is limited in time and is often below expectations. This is why many patients prefer not to leave their home, or leave very little time to avoid this problem.

With the oxygen concentrator, this fear does not exist: thanks to the possibility of producing oxygen wherever you are and thanks especially to the possibility of using the oxygen concentrator or recharging it. Wherever (at home, in a restaurant, in a car, etc.), autonomy is virtually unlimited and the psychological prison is no longer necessary.

Hubs, on the other hand, are power tools and as such, they may have potential failures or blockages (just like mobile phones), so they can stop working without notice; the latest generations of medical devices (such as Inogen One) are particularly safe and have difficulty with electrical or electronic problems.

The weight

Another fundamental aspect to consider in choosing between oxygen concentrators and portable bottles is the weight: on average, a stroller weighs 3-4 kg or even more when it is totally full of oxygen. Modern portable oxygen concentrators are real featherweight: just think of the Inogen One G3 concentrator which, with the battery inserted, weighs just 2.2 kg (indeed, it is currently the lightest concentrator in the world). ). The battery itself often determines the weight: with a battery of greater duration, the autonomy will be higher but the weight to be carried with oneself will also be higher.

For example, the Inogen One G2 concentrator with 12-cell battery has a battery life of about 4 hours and weighs 3.1 Kg; if you want to double the autonomy, ie 8 hours, you have to use a 24-cell battery, but the total weight of the device is 3.9 Kg.


For patients who feel very limited in their daily lives, the portable oxygen concentrator is the only way to enjoy an absolutely normal life. In both clinical and psychological terms, the concentrator represents the solution that allows a radical change in life: to try it is to adopt it. However, even for patients who do not require special mobility, the portable or fixed oxygen concentrator is an optimal solution: with this device, it is certain to never remain without oxygen.