According to epidemiological investigation, at least 60million people in China suffer from sleep apnea, but only a few people have been clinically diagnosed. Guotuiheng, director of the sleep medicine center of Beijing Chaoyang Hospital, believes that there are many reasons for this situation, which may be related to the relatively small number of sleep professionals in China, or to the relatively insufficient and complex methods of hospitals that can carry out sleep breathing monitoring. In addition, some studies in the past two years have shown that patients with COVID-19 with sleep disordered breathing have a significantly increased risk of developing into severe or critical illness. However, due to the epidemic prevention and control requirements in special periods, the diagnosis and treatment rate of patients in the hospital is relatively reduced, which is a great challenge for the diagnosis and treatment of sleep disordered breathing in clinical practice. "The traditional way to evaluate sleep is to accurately calculate the sleep time of patients through sleep breathing monitoring at night." Guotuiheng said that patients usually need to take a nap in the sleep center. Through sleep monitoring, they can obtain polysomnography including EEG, eye movement diagram, electromyography and other sleep information to evaluate their sleep. At the same time, it is also necessary to understand the abnormal respiratory events of patients through the evaluation of respiratory information, including mouth nose airflow breathing, chest and abdomen breathing movement, blood oxygen saturation, snoring and other information, and to understand the heart condition through the ECG monitoring chart, and conduct other evaluations through the indicators such as blood pressure and lower limb electromyography, and finally form a sleep monitoring report to evaluate the sleep structure and sleep quality. However, sometimes because of wearing too many sensors, patients are disturbed by them and can not sleep as usual. Therefore, patients often complain of poor sleep and affect the evaluation results. Moreover, such a complex examination process must be operated by qualified technicians, which is difficult for grass-roots hospitals. If we find a simpler method that can replace the traditional sleep monitoring in some functions, it may greatly improve the monitoring efficiency. "Through the curve analysis of clinical monitoring data, we found that the patient's abnormal breathing event (apnea) must have occurred in the sleep state, which is also the patient's sleep time. Continuous observation found that apnea is highly correlated with blood oxygen saturation." Guocuiheng explained that a certain period of apnea will lead to a significant decrease in blood oxygen saturation. Therefore, we can evaluate the apnea situation according to the corresponding oxygen desaturation index and apnea index, and then evaluate the risk in sleep. In addition, we also found that through the monitoring of blood oxygen saturation, we can also measure a very important information is pulse. The changes of pulse and heart rate are closely related to the functional state of autonomic nerve, and the change law of the functional state of autonomic nerve is closely related to the change range of respiration. In this way, the respiratory information of patients can be estimated through some special algorithms, which is also a very important means for sleep respiratory monitoring. It should be emphasized that the monitoring of blood oxygen saturation in the field of sleep is not the same as the commonly used oximeters in the field of intensive care and respiratory care. According to dongxiaosong, chief physician of respiratory medicine of Peking University People's Hospital, dynamic monitoring of blood oxygen saturation has great application value in the field of sleep. Peking University People's hospital has been deeply engaged in the field of sleep respiration for nearly 30 years, and has made some exploratory research on the monitoring of blood oxygen saturation at home. In recent years, wearable devices for sleep monitoring are usually used in sleep centers, snoring screening centers and physical examination centers to count oxygen reduction events and oxygen reduction index to preliminarily screen sleep apnea syndrome. Nowadays, portable sleep breathing monitor is expected to be more widely used in clinic. For example, wearable oxygen saturation breath sleep monitor can monitor blood oxygen at home. Hanfang, Secretary General of the world sleep society and director of the sleep center of the people's Hospital of Peking University, said that this is like the ECG Holter, which continuously records 24 hours through the instrument and is included in the disease screening management, so that patients can give feedback and guidance to patients through the platform medical staff without going to the hospital. But Han Fang also stressed that any technology will have limitations. Blood oxygen saturation monitoring is a very important vital sign of the body. Finally, how can it be applied to clinical practice? We also need to develop and establish a chronic disease management model to overcome the limitations of technology. (outlook new era)