Trial of measurement of sleep apnea syndrome with sound monitoring and SpO2 at home

Sleep apnea syndrome (SAS), which is associated with symptoms like chronic snoring, sleep apnea, and daytime excessive sleepiness, causes problems in daily lives. It has been pointed out that sleep of those who have apnea attacks is characterized by snoring in many cases, and thus attempts have been made to conduct screening for sleep apnea syndrome by analyzing snoring sounds. However, using snoring sound for screening is not practical at present because enormous effort is required in order to analyze each individual´s overnight snoring sound for a clinical application purpose. As just described, screening for sleep apnea syndrome has been regarded as being considerably troublesome. In addition, snoring sound with relatively less noise can be collected in well-equipped environments such as a sleep disorder center, but, collecting snoring sound at home suitable for analysis is likely to be difficult because numerous different kinds of noise sources exist at home. With intent to improve such situations, use of an IC recorder with a bone-conduction microphone and a simple SpO2 monitor was considered and sound processing was used to eliminate noise in this study this time with expectation that such application of those devices will minimize patients´ psychological burdens because staying overnight at hospital to undergo an examination in an extensively-equipped room will become unnecessary. As reduction of SpO2 during sleep results in sleep quality deterioration, it was studied if comparison between the SpO2 and pulse data and the snoring sound data, both of which were collected during sleep, could be helpful in order to grasp respiratory status during sleep and evaluate sleep quality, using the main symptom of sleep apnea syndrome, snoring.