[Rinsho Byori 51 : 790〜797, 2003]

Novel Apnomonitor for Use at Home

Hiroko MITANI*1, Yoji ISHIYAMA*2 and Yasuyuki SHIRAI*3

The monitoring technique for assessing suspected sleep apnea syndrome is a polysomnogram(PSG) performed in hospital. The typical PSG includes EEG, EOG, EMG, air flow at the nose and mouth, SO2, thoracicoabdominal motion and snoring sound. But the PSG test is expensive, and also is a stress load for the patient because this test requires recording throughout the night. Recently, a home-type apnomonitor that is used at home has been developed for the screening of apnea, but this monitor can not distinguish obstructive sleep apnea(OSA) from central sleep apnea(CSA). We evaluated a new home-type apnomonitor that was able to distinguish OSA from CSA using the change of amplitude in the fingertip plethysmogram and respiratory flow curve attained by oronasal transducer.
In this study, the respiratory flow curve became flat under OSA conditions, but the change of amplitude on plethysmogram corresponded to thoracicoabdominal motion. On the other hand, the change of amplitude in the plethysmogram did not corresponded with thoracicoabdominal motion under CSA conditions. These findings suggest that it is possible to distinguish between OSA and CSA using an apnomonitor system which records a respiratory flow curve and a plethysmogram, and also to develop a new home-type apnomonitor.

*1Department of Clinical Physiology, School of Health Sciences, Kyorin University, Hachioji 192-8508