Reduced pharyngeal muscle tone can cause trapped closure of the upper airway during inspiration. In normal NREM sleep phase, the basal tone of upper airway muscles decreases, the upper airway caliber decreases, and airway resistance increases, but the firing phase of upper airway muscles and the rhythmic contraction of intercostal muscles remain intact. during REM sleep, the basal tone of upper airway muscles, intercostal muscles, and most skeletal muscles are further suppressed. What tests are required for airway trapping closure? The following are the tests that need to be done for airway trapping closure: EMG: EMG is an adjunct to the examination of disease through electromyography. Ventilation to perfusion ratio (V/Q): The ratio of whole lung alveolar ventilation to the amount of blood flowing through the whole lung is called the ventilation and blood flow ratio. EEG: EEG is a graph obtained by recording the spontaneous biopotentials of the brain from the scalp with amplification through an instrument. ECG: The heart is excited by the pacing point, atria, and ventricles successively during each cardiac cycle, accompanied by changes in bioelectricity, and the graphs of various forms of potential changes (abbreviated as ECG) are elicited from the body surface through an electrocardiographic tracer. ECG is an objective indicator of the process of occurrence, propagation and recovery of cardiac excitation. ECG is the earliest, most commonly used and most basic diagnostic method in the diagnosis of coronary artery disease. Pulmonary ventilation function: Pulmonary ventilation function is a dynamic indicator of the process of air entry into the alveoli and exhaust gas discharge from the alveoli, containing the concept of time. Commonly analyzed indicators include resting ventilation, alveolar ventilation, maximal ventilation, temporal spirometry and some flow rate indicators. Polysomnography (PSG): Polysomnography (PSG) is the most important test for the diagnosis of sleep snoring (sleep apnea hypoventilation syndrome, OSAHS). Through continuous monitoring of respiration, arterial oxygen saturation, EEG, ECG, heart rate and other indicators at night, we can understand whether the snorer has apnea, the number of pauses, the duration of pauses, the lowest arterial oxygen value when the pauses occur and the degree of impact on physical health, which is the internationally recognized gold standard for diagnosing sleep apnea hypoventilation syndrome.