A sleep apnea syndrome detection system

Sleep apnea syndrome (SAS) is a sleep disorder that causes a patient to intermittently stop breathing for longer than 10 seconds and more than 30 times in seven hours. We have developed a new system for non-invasive detection and analysis of SAS. The system consists of a piezoelectric sensor, a microcontroller, a compact flash memory and a laptop computer. The piezoelectric sensor, whose electrical polarization voltage is produced by mechanical strain, is attached to the patient's chest and detects body movements. The low frequency components, mainly generated by respiration, are stored in the compact flash memory. After recording, the data are downloaded to a laptop computer, which then detects whether the patient is in SAS from the amplitude and frequency components of the timed thoracic body movement changes. The system can be used at home and be self-applied by the patients.