MVV in clinical practice mainly refers to the maximum ventilation per minute, this lung function reference value between men and women there are differences, the normal MVV reference value for men is (104 + 2.71) L/min, the normal MVV reference value for women is (82.5 + 2.17) L /. MVV is measured in clinical practice by multiplying 12 breaths at maximum speed by five. In general, MVV is used to measure the strength of respiratory muscles, the elasticity of thoracic lung tissue, and the resistance of the airway. It is mainly used for people with dyspnea or signs of hypoxia. It should be noted that the examinee should try to avoid nervousness and cooperate with the doctor so as not to affect the test results. Meanwhile, if you are physically weak or mentally abnormal and cannot cooperate, you need to avoid this test.