The machine works to produce oxygen with a concentration range 90%-96% (V/V) with air as the raw material by resorting to molecular sieve PSA technology . Object Of Use: The Machine is intended for use by the practitioners in medical institutions and patients. The machine should be used under the guidance and a doctor. Users should read the instructions mannual intensively to obtain the basic general knowledge of operation. Contraindications: The machine should not be used for patients with severe carbon monoxide poisoning or for emergency treatment of critically ill patients. The oxygen produced by the machine should not be used for non-breathing purposes, and should not be used as oxygen inhalation for the support or continuation of life.