title: Respiration and body movement analysis during sleep in bed using hetero-core fiber optic pressure sensors without constraint to human activity.
abstract: We describe respiration monitoring in sleep using hetero-core fiber optic pressure sensors. The proposed hetero-core fiber optic sensor is highly sensitive to macrobending as a result of the core diameter difference due to stable single-mode transmission. Pressure sensors based on hetero-core fiber optics were fabricated to have a high sensitivity to small pressure changes resulting from minute body motions, such as respiration, during sleep and large pressure changes, such as those caused by a rollover. The sensors are installed in a conventional bed. The pressure characteristic performance of all the fabricated hetero-core fiber optic pressure sensors is found to show a monotonic response with weight changes. A respiration monitoring test in seven subjects efficiently demonstrates the effective use of eight hetero-core pressure sensors installed in a bed. Additionally, even in the case of different body postures, such as lying on one's side, a slight body movement due to respiration is detected by the hetero-core pressure sensors.
authors.affiliation: Soka University, Faculty of Engineering, Information Systems Science, 1-236 Tangi-machi, Hachioji, Tokyo 192-8577, Japan. mnishiya@soka.ac.jp
authors.forename: Michiko
authors.initials: M
authors.lastname: Nishyama
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006801:Humans; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D009068:Movement / Q000502:physiology*; D017286:Polysomnography / Q000295:instrumentation*; D015656:Respiratory Mechanics / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D014160:Transducers, Pressure