Abstract:Oxygen is essential to life on Earth. The oxygen obtained by human respiration is consumed within the mitochondria, mainly for oxidative phosphorylation to produce energy. Too little or too much oxygen can easily cause great harm to humans. When oxygen is too low, it can lead to insufficient oxygen supply to tissues and organs, resulting in dysfunction and death in severe cases. When there is too much Oxygen, the body cannot consume the excess oxygen, so that the cells are in a state of high oxygen, resulting in the production of a large amount of reactive oxygen species (ROS), which further causes oxidative damage to the cell membrane and organelles, leading to oxygen toxicity. Although the human body has multiple oxygen-sensing mechanisms to prevent organs and cells from suffering from hypoxia and hyperoxia-induced oxidative stress, but in oxygen therapy, especially in the process of oxygen inhalation in the elderly, continuous real-time individualized monitoring and guidance are still particularly important, in order to maximally avoid or reduce oxygen toxicity during the treatments for hypoxemia and tissue hypoxia correction.