Pulmonary function detection of mixed gases

The lung function test is mainly used to know whether there is damage to the respiratory system and the damage situation. The tested patients can detect the corresponding pathological indicators of the lung by detecting the mixed gas of respiratory lung function. The common lung function detection mixed gas has the following kinds:

• CO+He+O₂+N₂ balance gas
• CO+CH₄+O₂+N₂ balance gas
• CO₂+O₂+N2 balance gas
• C₂H₂+O₂+N₂ balance gas
• CO+He+C₂H₂+O₂+N₂ balance gas

The role of carbon monoxide is to bind to hemoglobin. In a healthy person, when carbon monoxide binds to hemoglobin, there is no carbon monoxide in the result of exhalation. But a smoker's breath results in carbon monoxide because its hemoglobin is saturated.

Helium, on the other hand, takes advantage of its super permeability. In healthy lungs, helium can be permeated well. If there is no helium in the exhalation, the lungs are healthy. If tiny particles enter the lungs (such as SiO₂ inhaled by pollution from a glass or ceramics factory), the helium cannot penetrate in some places.