ABSTRACT
Background: Orientation is a significant factor in architectural design that may affect well-being. Body direction does not change during sleeping, and sleeping is sensitive and affected by environmental factors. Aims: This neuroarchitecture study aimed to assess the effects of bed orientation on sleep quality to enhance bedroom design. Materials and Methods: To do so, the effects of earth's electromagnetic field (EMF) on sleep electroencephalography (EEG) signals were evaluated using signal processing techniques. In this cross-sectional study, a total of 21 healthy volunteer participants slept for two consecutive naps, at two rooms with identical interior design and different bed orientations, toward and against earth's EMF in a sleep clinic. Statistical Analysis: In this experiment, discrete wavelet transform extracted five subfrequencies of EEG data as delta, theta, alpha, beta1, and beta2. In addition, the energy signals were computed by measurement of wave frequencies. The mean total sleep time was 1.63 h in North–South (N-S) earth's EMF orientation and 1.38 h in the other direction. Results: t-test results showed significant changes in delta, theta, and alpha frequencies in terms of bed orientation. There was a significant result in the alpha energy ratio over the whole signal energy. Furthermore, there were increases in the average energy of delta, theta, and alpha bands in N-S versus East–West (E-W) bed directions. Conclusions: This study indicated that sleep in N-S direction could be more beneficial than E-W and the sleep EEG signals can be sensitive to earth's EMF. The results show the importance of considering orientation in bedroom design and its benefits on inhabitants' well-being.
ABSTRACT
Traffic fatalities are a major cause of morbidity and mortality in Iran. Occupational sleep medicine field needs more cost-effective and applicable tests for screening purposes. This study reports on a pilot screening study for drowsy drivers in an urban Iranian sample of commercial drivers. The Maintenance of Wakefulness Test [MWT] measures the ability to remain awake objectively. Sleep latency in MWT is a reasonable predictor of driving simulator performance in drivers. In this study, we evaluate whether the Epworth Sleepiness Scale [ESS] and MWT are equally useful in drivers with possible Excessive Daytime Sleepiness [EDS]. 46 consecutive road truck drivers in a transportation terminal entered into this study. The ESS score of patients with normal and abnormal MWT was 3.24 +/- 2.4 and 4.08 +/- 3 respectively which was not significantly differenced [P value = 0.34]. No significant correlation was found between the ESS and sleep latency in MWT [r=-0.28, 95%CI= -0.58 to 0.02]. By using the receiver operating characteristic analysis, the area under the curve was found to be 0.57 [95% confidence interval = 0.37- 0.77] which is not statistically acceptable [P value=0.46]. Our finding showed that the MWT and ESS do not measure the same parameter