Study And Development Of Sleep Apnea Syndrome Detection Equipment Based On Pulse And Oxygen Saturation

sleep apnea syndrome(SAS)is a common sleep disorder,which seriously threatens the quality of life and health.Polysomnogram(PSG)is the gold standard for clinical diagnostic.However,causing to its complex operation process,high cost and easy to cause physical and mental problems on patients,PSG is very difficult to promote in family life.At present,the heart rate variability(HRV)method is one of the main methods to replace PSG.It uses holter to monitor the patient’s ECG signal and analysis HRV of the patient to detect SAS.But this method has also many shortcomings such as easy to cause skin allergies.Pulse wave signal contains a large number of human physiological information,in recent years,many experts and scholars committed to the study the relationship between HRV analysis based on RR interval and the pulse rate variability(pulse rate variability,PRV)based on pulse signal peak to peak interval,and the research results show that these two methods were highly correlated that can be replaced.Under this background,the study and development of SAS detection device based on pulse and blood oxygen signal is carried out.Based on the detection method of photoplethysmography(PPG),a new type of pulse oximeter is designed and developed.The substrate for the probe is made by a textile cloth which has with a velcro structure at both sides that can be stable and more comfortable than the finger clip probe which is easily falling out during long-term sleep monitoring.Then we analyze the effect of the sensor position on the measurement results which verify the validity of the surround probe.Through the hardware circuit,we carry out the acquisition and transmission of PPG signal.Based on the principle of wavelet multi-resolution analysis,we correct the baseline wander which will influence the peak amplitude,and then identifies the peak automatically by using the quadratic spline wavelet modulus maximum algorithm,and completes the calculation of blood oxygen saturation.Compared with the oximeter which is popular on market,the resultof the blood oxygen saturation measurement error is ±1% that will meet the requirements of sleep monitoring.Finally,according to the results of theoretical research and routine detection parameters,the PRV analysis and blood oxygen saturation analysis were obtained,and then 14 feature parameters which are closely related to SAS detection are determined.In summary,study and development of SAS detection equipment based on pulse and blood oxygen saturation will provide a feasible technical scheme for early screening and diagnosis of SAS patients,which is suitable for long-term sleep monitoring and has important practical value.