Patients: How should I choose an oxygen machine? Professor Shen Ning: Basically, hospitals do not use oxygen concentrators, which are mainly used by patients at home. In the beginning, the oxygen concentration produced by oxygen concentrators was not high, but in recent years, the process of oxygen concentrators has improved significantly, and the concentration of oxygen produced can basically reach 90% or more. When choosing an oxygen machine, patients should first ensure that the oxygen concentration of the oxygen machine can reach 90%, and most of the oxygen machines on the market can meet this requirement. Secondly, we need to pay attention to the stability of the oxygen machine performance. Because patients with chronic obstructive pulmonary disease have a long oxygen intake time, up to 15 hours a day or more, and have to inhale oxygen for many years. Patient: There are also ventilators on the market, what is the difference between this oxygen machine? Prof. Shen Ning: Most of the ventilators used at home are non-invasive ventilators, which have a different principle than oxygen concentrators. The ventilator is positive pressure ventilation, that is, there is an auxiliary effect to help the patient breathe while inhaling oxygen, while the oxygen therapy applied to the oxygen machine has no auxiliary effect, but only the simple administration of oxygen. For the time being, oxygen therapy has clear indications and a clear effect, while there is no clear consensus on what kind of patients need to use a non-invasive ventilator at home. In Western countries, more and more patients are starting to use non-invasive ventilators, which may improve prognosis and prolong survival, but it is not very clear yet. Patients: Is it also necessary to pay attention to safety when using oxygen concentrators? Prof. Shen Ning: When using oxygen concentrators, you must read the manual carefully, after all, it is not a conventional household appliance. Because oxygen is a flammable gas, when applying the oxygen machine, it must be far away from the stove, heating; at least 20 centimeters away from the wall to prevent overheating; avoid open flames; do not have a huge vibration when moving; and so on. However, patients should not be overly worried and feel like sleeping with a dynamite pack on their backs every day. Oxygen therapy is still very safe as long as patients are clear about all the precautions and reduce the risk of occurrence.