We will simple explain from: the flow range of medical grade oxygen, the scope of inhalation oxygen concentration, main applicable people, 4 for non-invasive ventilator compatibility, capacity to bear the work load, pictures of the domestic market, these six aspects.

1.3 Different range of medical-grade oxygen flow in helicopters and helicopters and 5 helicopters

When the oxygen flow rate of the 3-liter oxygen generator is 1~3 liters.

The “oxygen concentration” reaches 90%~96%, that is, the oxygen flow rate of the 3-liter oxygen generator per minute. When the user selects 1 liter per minute, 2 liters per minute, and 3 liters per minute, it can provide oxygen concentration of 90%~96%. It should be noted that although some 3-liter oxygen generator can be adjusted to the volume of 4 or 5 liters, in this case, the oxygen output concentration of the machine is no longer 90%~96%. With the increase of oxygen output flow, the oxygen output concentration will decrease to about 70% at 5 liters. When the oxygen flow rate of the 5-liter oxygen generator is 1~5 liters, the “oxygen concentration” reaches 90%~96%, that is, the 5-liter oxygen generator not only includes: when the oxygen flow rate per minute is 1 liter, 2 liters, and 3 liters, the oxygen concentration is 90%~96%. At the same time, choose 4 litres per minute, 5 litres per minute, it can provide oxygen therapy oxygen concentration of 90% to 96%.

Ii.3 and 5 helicopters have different “aspirated oxygen concentration” FiO2 values

What is the inhaled oxygen concentration FiO2?

The Fraction of oxygen concentration that is inhaled is called FiO2. Often used to represent the percentage of oxygen in the alveoli that is involved in gas exchange.

Because the range of medical oxygen flow provided by a 3-liter oxygen concentrator and a 5-liter oxygen generator is different, when you use the most common device, the nasal oxygen tube (also known as a nasal catheter, or a nasal straw), for oxygen flow, there is a difference in the concentration of FiO2 inhaled.

The “standard nasal oxygen tube”

The “standard nasal oxygen tube” is a low-flow oxygen inhalation device, often used for oxygen therapy of no more than 6 liters/min. It belongs to the open oxygen inhalation. The actual oxygen concentration that reaches the lungs is the oxygen concentration after oxygen from the oxygen generator is mixed with air.

Nasal oxygen tube method.

If the most common nasal oxygen tube is used for oxygen inhalation, the formula for the estimated value of inhaled oxygen concentration FiO2 can be obtained from the oxygen discharge rate and oxygen concentration.

Estimated value of inhaled oxygen concentration FiO2 = 21% + 4 × oxygen output flow per minute (l) × oxygen output concentration of oxygen generator (%).

Oxygen concentration respiratory data.

Based on the above formula,we can get the corresponding data of 3 liters of domestic oxygen generator, oxygen flow rate and estimated FiO2 (oxygen concentration inhaled) : oxygen flow rate (l/min), oxygen concentration (%), estimated FiO2 (with nasal oxygen tube).

  • 1 l/min 90% to 96% 24.6% to 24.84%
  • 2 l/min 90% ~ 96% 28.2% ~ 28.68%
  • 3 l/min 90% to 96% 31.8% to 32.52%

Similarly, we can also obtain the corresponding data of 5 liters of domestic oxygen generator, oxygen flow rate and FiO2 (oxygen concentration inhaled) estimate:

Oxygen flow rate (l/min) Oxygen concentration (%) Estimated value of FiO2 (with nasal oxygen tube)

  • 1 l/min 90% to 96% 24.6% to 24.84%
  • 2 l/min 90% ~ 96% 28.2% ~ 28.68%
  • 3 l/min 90% to 96% 31.8% to 32.52%
  • 4L/min 90% ~ 96% 35.4% ~ 36.36%
  • 5 l/min 90% ~ 96% 39.0% ~ 40.20%

Three, 3 litre oxygen machine and 5 litre oxygen machine applicable people are different.

1 liter and 2 liter oxygen generator.

1 liter, 2 liter oxygen generator is mainly used for health care oxygen intake for people with slight hypoxia, such as pregnant women and white-collar workers with slight hypoxia.

3 liter oxygen generator.

3 liter oxygen generator, mainly used for: mild and moderate respiratory diseases, cardiovascular and cerebrovascular diseases, three higher population.

5-liter oxygen generator.

5-liter oxygen generator is mainly used for patients with severe diseases, people who need to use ventilator, and people who need to take oxygen for a long time every day: copd, pulmonary fiber, pulmonary resection, lung cancer, pneumoconiosis, silicosis and other people.

Heli and Helicopter compatibility with “non-invasive household ventilators” will be different.

The non-invasive ventilator used in homes is different from the non-invasive ventilator used in hospitals. The oxygen source is often provided by an additional oxygen generator, because the mask has a “storage effect” of carbon dioxide, and the pressure in the mask is relatively large, generally less than 5 liters/ At a minute oxygen flow rate, oxygen cannot enter the mask well, so naturally it cannot enter the airway and lungs, nor can it expel the exhaled carbon dioxide out of the mask.

In addition, due to the large air flow in the mask, the incoming oxygen will be severely diluted. Therefore, if the low-flow oxygen output of the 3-liter oxygen generator is connected to a non-invasive domestic ventilator, it often cannot meet the patient’s oxygen demand, which affects the patient’s treatment effect.

Therefore, when patients need to connect a home-use non-invasive ventilator to an oxygen generator, doctors often suggest that they need at least a 5-liter home oxygen generator or a larger flow oxygen generator to be more appropriate.

5. The molecular sieve dosage and compressor performance of the 3-liter and 5-liter machines are different, and the working load they can bear is different. Generally speaking, the amount of molecular sieve filled inside a 5-liter oxygen generator is less than that of the 3-liter oxygen generator. More, at the same time, its power components are also the main cost, and the air compressor in the oxygen generator can withstand more workload. More suitable for people who need long-term oxygen therapy every day. For example, for people with COPD, they should use a 5 liter oxygen generator more than a 3 liter oxygen generator.

In the flow of oxygen inhalation.

In the flow of oxygen inhalation, people with COPD should take a low flow rate: 1.5 to 2.5 liters of oxygen per minute for oxygen therapy, which will make some people think that as long as 3 liters of oxygen generator is enough, however, in oxygen inhalation In terms of time, for people with COPD, the amount of oxygen therapy required per day is relatively long. They are often advised that the daily oxygen therapy should not be less than 15 hours. If allowed, it is best to 24 Oxygen inhalation.

3 liter oxygen generator, only 1.5 to 2.5 liters per minute, the air compressor on the 3 liter machine has carried a certain workload, and then 15 hours or 24 hours of long-term work, which makes the life of the compressor A sharp drop can easily lead to machine failure.

5 liter oxygen generator, many companies have designed the 5 liter oxygen generator as a 24-hour operation mechanism, the displacement of the compressor is greater, the performance is stronger, when choosing 1.5~2.5 liters, because the 5 liter compressor It has a larger displacement and more surplus. Although the displacement of the 5-liter compressor has been attenuated during a long period of operation, it can also meet the minimum requirements of the system and have a longer overall life. This kind of oxygen inhalation mode for people with COPD is more stable and suitable. This is an important reason why many professional physicians recommend that they use a 5-liter oxygen generator.

In particular, for users who turn on the phone for 15 hours or 24 hours, they often also take oxygen during the night rest. Among the 5-liter oxygen generators, there are many high-end silent and high-quality oxygen generators. , To better meet their oxygen needs.

VI. Domestic market situation:

Due to national conditions, prices and other factors, domestic consumers choose 3 liters more

Oxygen generators In the European and American household medical oxygen generator market, well-known European and American household medical oxygen generator companies will produce 5 liter oxygen generators, followed by wearable pulse portable oxygen generators, and then 10 liter oxygen generators. machine. The 3 liter oxygen generator is only launched by a few companies, but no well-known enterprises have launched a 1 liter home oxygen generator. European and American consumers also buy 5 liter home oxygen generators and pulse portable oxygen generators.

In the domestic family medical oxygen generator market.

In the domestic family medical oxygen generator market, many companies produce 1 liter, 3 liter, and 5 liter oxygen generators. This gives consumers more choices. Although the 5-liter oxygen generator is more versatile, because the 3-liter oxygen generator has a more price advantage, there are currently more people choosing the 3-liter oxygen concentrator.

In addition, in order to increase sales, some domestic merchants will package into “European and American” brands, such as: American brands, German brands, etc., to increase prices. It is recommended that consumers treat foreign brands if they encounter European and American brands, produce 1 liter, 3 liters Be careful about the oxygen concentrator.

Cite this article as:
Editorial Staff, "What is the difference between a household oxygen concentrator with 3 litres and 5 litres?," in Medicalopedia, July 18, 2020, [Permalink: https://www.medicalopedia.org/9082/what-is-the-difference-between-a-household-oxygen-concentrator-with-3-litres-and-5-litres/].