The working principle of polysomnography
Polysomnography mainly relies on the electrodes affixed to a person's body to monitor the data of EEG, ECG, EEG, EMG, EMG, thoracic and abdominal respiratory movements, snoring, pulse, oxygen saturation, pulse wave, respiratory rate, body position, etc., and then analyzes the data to determine the patient's sleep condition and possible problems.
Polysomnography can objectively evaluate the patient's sleep quality, conduct the monitoring of sleep time, sleep efficiency and staging, and exclude the sleep cognitive misconceptions, so that the patients can correctly recognize their own sleep problems, and have an objective evaluation and understanding of their own sleep quality. Staging and grading can be performed for patients with sleep breathing disorders. In addition, different leads are set up for different sleep disorder events of the patients, such as periodic leg movements and restless leg syndrome, and their relevant monitoring is carried out in order to fully recognize the etiology that causes insomnia.
What are the contents of polysomnography monitor
1.Sleep condition
The sleep condition and staging are accurately reflected by recording EEG, EEG, EMG
Electroencephalogram: it is necessary to distinguish between sleep and wakefulness, each stage of sleep and the proportion of each stage.
Electrooculogram: to distinguish between REM and NREM according to whether the eyeballs are moving or not.
Electromyography: to record the electrical activity generated by the muscle activity in the jaw area, to assist in distinguishing between REM and NREM.
2. Breathing condition
Nasal airflow: to sense the temperature difference between the exhaled air and the inhaled air by using temperature sensitive thermistor to know whether there is or there is not airflow, and determine whether there is any airflow or not. presence or absence to determine whether sleep apnea has occurred.
Chest and abdominal movement: the presence or absence of chest and abdominal activity is sensed by electrical resistance or other conductive substances in the chest and abdominal belt to distinguish between central or obstructive sleep apnea.
Oximetry: Continuous collection of blood oxygen saturation by a sensor clipped to the finger can give an idea of the duration and degree of oxygen deprivation throughout sleep, which is helpful in determining the severity of sleep apnea syndrome and estimating the effectiveness of treatment.
3, heart condition
Through the electrocardiogram to understand the whole sleep process heart rate and electrocardiogram waveform changes, analyze the relationship between various arrhythmias and other abnormal waveforms and apnea, to assess the treatment effect.
4, snoring
The above three aspects are sufficient to diagnose sleep apnea syndrome (OSAS), but some polysomnographs also record snoring to understand the nature of snoring, the relationship between sleep apnea and its frequency spectrum; there are also position sensors, which can record the patient's body position changes in the course of sleep, to understand the relationship between the apnea and the sleeping position, so as to avoid the diagnosis of a number of only the supine position of the apnea. In order to avoid missing the diagnosis of some apnea that only occurs in the supine position.