Gih Sung Chung et al 2009 Physiol. Meas. 30 1327 doi:10.1088/0967-3334/30/12/003
Gih Sung Chung1, Byung Hoon Choi1, Jin-Seong Lee2, Jeong Su Lee1, Do-Un Jeong3 and Kwang Suk Park4,5
Show affiliationsPolysomnography (PSG) is currently considered the gold standard for assessing sleep quality. However, the numerous sensors that must be attached to the subject can disturb sleep and limit monitoring to within hospitals and sleep clinics. If data could be obtained without such constraints, sleep monitoring would be more convenient and could be extended to ordinary homes. During rapid-eye-movement (REM) sleep, respiration rate and variability are known to be greater than in other sleep stages. Hence, we calculated the average rate and variability of respiration in an epoch (30 s) by applying appropriate smoothing algorithms. Increased and irregular respiratory patterns during REM sleep were extracted using adaptive and linear thresholds. When both parameters simultaneously showed higher values than the thresholds, the epochs were assumed to belong to REM sleep. Thermocouples and piezoelectric-type belts were used to acquire respiratory signals. Thirteen healthy adults and nine obstructive sleep apnea (OSA) patients participated in this study. Kappa statistics showed a substantial agreement (κ > 0.60) between the standard and respiration-based methods. One-way ANOVA analysis showed no significant difference between the techniques for total REM sleep. This approach can also be applied to the non-intrusive measurement of respiration signals, making it possible to automatically detect REM sleep without disturbing the subject.
Issue 12 (December 2009)
Received 1 March 2009, accepted for publication 2 October 2009
Published 28 October 2009
Gih Sung Chung et al 2009 Physiol. Meas. 30 1327
Messrs Negretti and Zambra 1934 J. Sci. Instrum. 11 395
X H Ji et al 2004 J. Phys. D: Appl. Phys. 37 1472
L C Garcia de Andrade 2001 Class. Quantum Grav. 18 3907
Paul K Townsend and Mattias N R Wohlfarth 2004 Class. Quantum Grav. 21 5375
A J M Medved et al 2004 Class. Quantum Grav. 21 3111
S Deser et al 2004 Class. Quantum Grav. 21 5295
K S C Kuang et al 2002 Meas. Sci. Technol. 13 1523
G Bergqvist and P Lankinen 2004 Class. Quantum Grav. 21 3499
Tuomo S Silvast et al 2009 Phys. Med. Biol. 54 6823