**Abstract**

A noninvasive sleep apnea syndrome (SAS) sensor using optical fibers, the "F-SAS sensor," has been evaluated in a clinical application ranging in age from 13 to 78 years and with BMIs of 19.2–39.3. The respiratory disturbance index (RDI) from the F-SAS sensor corresponded well with the apnea hypopnea index (AHI) from polysomnography (PSG). Concurrent measurement of the RDI and the AHI had a correlation coefficient of 0.71. This means that the F-SAS is well-suited for preliminary SAS screening. They would also be useful for screening potential SAS sufferers during normal sleep at home. Then, we have succeeded in downsizing F-SAS sensor and have recognized that it is highly correlated with PSG and pulse oximetry. Next, we applied the compact F-SAS sensor to examining SAS diagnosis in a child patient (2–12 years) and report on improved pediatric analysis. The analysis results revealed the correlation value to be R = 0.87 was a significant improvement over the correlation value of R = 0.697 between the AHI obtained by a sleep apnea syndrome examination apparatus (SAS 2100) and RDI obtained by the conventional F-SAS sensor.

**Keywords:** optical fiber sensors, sleep apnea syndrome, SAS, F-SAS sensor, noninvasive, plastic optical fiber
