Portable Sleep Apnea Hypopnea Monitoring Instrument

Obstructive sleep apnea syndrome(OSAS) is a serious threat to human health,which attracted widespread concern in the past 30 years. OSAS is sleep-breathing disorder characterized by a set of episodes of total and/or partial cessation of respiratory airflow while patient is asleep, also coupled with low oxygen saturation, snore and somnolence during the daytime. OSAS not only affects people's sleep quality, but also can lead to hypertension, cardiovascular diseases, etc. It becomes more and more important in the prevention, diagnosis and treatment of OSAS presently. Consequently, There is important significance in clinical to develop a portable sleep detecting device.Based on the method of photoelectric plethysmography and the Beer-Lambert Law, the algorithm of pulse frequence and oxygen saturation was present, the portable sleep detecting device characterized by low power dissipation, small size, cheap and suitable for family use was developed. In the part of hardware design,photoplethysmogram was detected with NELLCOR probe and relevant driver circuit; nasal respiratory wave was detected with HONEYWELL respiratory pressure sensor; In the part of software design, the driver is written with the C language on the platform of IAR. The fuction of data gathering, preprocedding, display, save and comminication was realized. The patient monitoring and diagnosis system was designed on the platform of VC++ 6.0, which can display the detected data and generate diagnosis result report.The system testing and clinical experiment was established, the sleep detecting device work well, which can detect photoplethysmogram and respiratory wave effectively, work out the pulse frequency and oxygen saturation, generate diagnosis report of sleep finally.