• Korean Journal of Psychosomatic Medicine
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• v.31 no.2
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• pp.149-154
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• 2023

Objectives : Far-infrared (FIR) lights have been investigated for sleep quality intervention. We sought to measure the advantageous effects of FIR in sleep using polysomnographic data as the objective outcomes. Methods : The ten healthy volunteers were enrolled in a single-center, prospective, patient-blind, single-arm trial. Individuals slept on a sham mattress and a FIR emitting mattress with polysomnography for one night each. Results : Sleep efficiency showed an increasing trend but was not statistically significant. PSQI-K significantly decreased (p=0.013). The latency to REM of the baseline was shorter than that of the intervention (p=0.008). Though there was no statistical significance, Stage N1 and N2 were shortened, and Stage N3 was prolonged after the intervention compared to the baseline. Conclusions : The FIR-emitting mattresses improved sleep quality on self-reported insomnia. We suggested the candidate for the markers altered by the FIR therapy, such as the normalization of REM latency and increased N3 sleep.

• Journal of Korean Biological Nursing Science
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• v.11 no.1
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• pp.23-31
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• 2009

Purpose: The purpose of the present study was to investigate the prevalence and related factors of sleep-wake disturbance (SWD) in Korean post-stroke patients. This study was the first to address post-stroke SWD in Korea using a structured questionnaire. Method: We investigated the prevalence of SWD and related factors including lesion location, stroke severity, presence of depression and fatigue. We assessed sleep-wake pattern including quality of sleep, sleep latency, wake episodes, wake time after sleep onset, daytime sleep episode and sleep time at daytime. Ninety stroke patients admitted to a university affiliated hospital in Seoul between the period September 2008 and January 2009 were included in the study. Result: Thirty five patients (38.9%) complained insomnia and 32 (35.6%) complained excessive daytime sleepiness (EDS). Quality of sleep (p=.000), sleep latency (p=.000) and total sleep time (p=.001) were significantly poorer in 16 patients with both insomnia and EDS than in the others. The related factors to insomnia were level of education (p=.030), depression (p=.007) and fatigue (p=.034), though related factors to EDS were stroke onset time (p=.049), stroke severity (p=.005), motor dysfunction (p=.035), dysphasia (p=.018), fatigue (p=.001) and lesion location (p=.019). Conclusion: Sleep-wake disturbance is a common problem in Korean stroke patients. Strategies to improve quality of sleep are urgently needed in the post-stroke patients.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.204-215
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• 2020

People who have sleep disorders such as insomnia take a long time to get to sleep, namely sleep latency. In order to reduce it, effective stimulations and environments to induce sleep such as ASMR or pink noise are necessary. However these have different effects and preferences for each individual. Therefore customized service and control for the sleep induction will be provide to him/her. In this paper, we proposed SIS control system which provides selectively sound control among various kinds of ASMR and pink noise according to sleep state measured from brain wave data for an individual. In order to verify the effectiveness of the system, we had conducted totally 30 experiments for 5 people, and all EEG data measured from all the people during sleep. An average of 3.7 hours was spent per experiment. In comparison experiments with and without sound control for sleep induction, the latency time was reduced by an average of 8 minutes as well as delta waves and theta waves, which appear only in deep sleep, are increased by 21%.

• Journal of Korean Academy of Nursing
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• v.29 no.1
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• pp.61-71
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• 1999

Sleep is a necessity for survival. Disruption of sleep leads to numerous adverse physiological and psychological consequences. These could be particularly undesirable for older patients, who are subject to many additional factors. But there is limited research related to hospitalized elderly in Korea. The purpose of the study is to explore sleep patterns and disturbing factors of before and after hospitalization, in order to present basic information regarding elderly sleep to develop nursing intervention. The sample consisted of 32 elderly men and women between the ages of n and 87 years. Data collection was done from September to November 1997. Measures of sleep patterns and related factors were obtained from self-reported sleep questionnaires. Analysis of data was done by use of t-test, paired t-test, ANOVA, and Pearson Correlation Coefficient. The results of this study were summarized as follows : 1. In comparision between before and after admission of their sleep pattern, “sleep onset” tends to be delayed and nocturnal sleep time was significantly reduced. So, hospitalized elderly reported less total sleep time than before admission. 2. Regarding the sleep disturbing factors, medication(hypnotics ; 37.5%), physiological factor (snoring ; 59.4%) environmental factor (pillow ; 78.1%), emotional factor(anxiety related to disease ; 37.5%), and illness factor(fatigue ; 34.7%) were reported. 3. Significant differences in gender were found. Men had more disturbances in sleep than women owing to difficulty in falling a sleep and lack of nocturnal sleep. Women consumed more sleep inducing drugs. Significant increase was reported in napping during the day with increasing age. 4. Significant differences between good sleepers and poor sleepers were found for the following variables : nocturnal sleep time, total sleep time, bed time, sleep onset latency time, sleep latency time after nocturnal awakening, time spent in bed upon arousal, environmental factors, and emotional factors. In conclusion, it was found that the quantity and quality of sleep were significantly altered in hospitalized elderly, but adequate strategies for better sleep were not practiced. Further research is needed to develop Intervention strategies to promote sleep and to prevent sleep problems.

• Sleep Medicine and Psychophysiology
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• v.7 no.2
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• pp.115-119
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• 2000

Objectives Summary: A 20-year-old man was presented with a history of difficult waking for 10 years. He suffered from morning headache, chronic fatigue and mild daytime sleepiness but had no history of irresistible sleep attack, cataplexy, hypnagogic hallucination or sleep paralysis. Methods: Night polysomnography (PSG), multiple sleep latency test (MSLT) and HLA-typing were carried out. Results: The PSG showed short sleep latency (4.0 min) and REM latency (2.5 min), increased arousal index (15.7/hour), periodic limb movements during sleep (PLMS index=8.1/hr) with movement arousal index 2.1/hr and normal sleep efficiency (97.5%). The MSLT revealed normal sleep latency (15 min 21 sec) and 4 times sleep-onset REM (SOREM). HLA-typing showed DQ6- positive, that corresponded at the genomic level to the subregion DQB1*0601, which was different from the usual locus in narcolepsy patients (DQB1*0602 and DQA1*0102). Conclusion: Differential diagnosis should be made with circadian rhythm disorder and other causes of primary waking disorder. The possibility of a variant type of narcolepsy could be suggested with an unusual clinical manifestation and a new genetic marker.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.1
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• pp.1-6
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• 2006

This study was performed to evaluate sleep efficiencies and conditions for comfortable sleep based on the analysis of EEGs and MST under four thermals conditions. Five female subjects who have similar life cycle and sleep patterns were participated for the sleep experiment. Their age was from 20 to 22 years old. They were healthy, and had regular sleep with consistent bed and wakeup time. It was checked whether they had a good sleep before the night of experiment. Experiments were performed in an environmental chamber of $4.1\times4.9\times2.7m$ size. EEGs were obtained from C3-A2 and C4-Al electrode sites. Sleep stages were classified, then TST, SWS latency and SWS/TST were calculated for the evaluation for sleep efficiencies on thermal conditions. As results, it was concluded that indoor thermal environments of $24\~26^{\circ}C$ was the best for comfortable and deep sleep.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.808-813
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• 2008

The study was to evaluate the air-conditioning of sleep algorithm. The algorithm was developed through the analysis of brain waves and MST, the experiments using air conditioner was performed in a apartment bedroom. Five female subjects were participated for the experiment. Eight hours of data collection a day was performed under different algorithm, case A, case B and case C. Physiological signals, EEG, ECG, EOG, and EMG, were obtained using polygraph and converted into digital signal. Then, subjects were asked to answer the questionnaire about their thermal sensation after experiment in bedroom. Sleep stages were classified, then TST, Sleep latency and Sleep efficiency were calculated for the three different air conditioner algorithm. As results, TST, Sleep efficiency, questionnaire showed the higher values for Case B algorism than that for other algorism. On the other hand, SWS latency was lower than for other conditions. Therefore, it was concluded that Case B of the algorithm was the best for comfortable and deep sleep.

• Nutrition Research and Practice
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• v.14 no.6
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• pp.606-620
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• 2020

BACKGROUND/OBJECTIVES: Although some juices affect subjective sleep quality, there is a lack of information on the effect of a specific juice on objective sleep quality and heart rate variability (HRV) during sleep; thus the present study investigated whether a blended juice made from natural extracts influenced sleep quality and HRV during sleep in adults with disturbed sleep. SUBJECTS/METHODS: A randomized, crossover study was conducted on twenty-five adults (15/10, female/male) complaining of difficulty initiating or maintaining nighttime sleep (Pittsburgh sleep quality index [PSQI] ≥ 5). During feeding sessions (FS), subjects received sleep-inducing juice made of natural ingredients (250 mL/trial) twice a day for 8 weeks or non-FS (N-FS) for 8 weeks while maintaining normal activities. Sleep quality and parameters were recorded via wearable actigraph for 7 consecutive days, and PSQI scores were assessed before and after the intervention. HRV was also monitored at rest and during sleep. RESULTS: After receiving the sleep-inducing juice intervention (FS), PSQI scores were significantly decreased (P < 0.001) and correlated with a significant decline in fatigue severity scale and visual analogue scale levels (P < 0.05; both). HRV indices of vagal activity were significantly improved during FS (P < 0.05), and no significant differences in N-FS were observed. Sleep efficiency and total sleep time increased significantly (P < 0.05) and sleep latency, total counts, sleep fragmentation index, and movement index, decreased significantly (P < 0.05, all 4) during FS, with no significant differences-observed during N-FS. CONCLUSIONS: This study results demonstrated that an 8-week course of sleep-inducing juice has led to improve sleep quality, suggesting an enhanced cardiac vagal tone during sleep. Thus, it could be a well-tolerated option for adults with disturbed sleep.

• Korean Journal of Psychosomatic Medicine
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• v.18 no.1
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• pp.30-39
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• 2010

Objectives：Assessment of sleep disturbance is an essential part of the diagnostic criteria used for several psychiatric disorders. Change in sleep patterns over time may indicate response to treatment. In clinical practice, sleep is usually evaluated subjectively by patient self-report. This study was aimed to compare subjective sleep assessment with objective sleep measurement by actigraphy in psychiatric inpatients. Methods：A total of 32 psychiatric inpatients were studied. Patients were asked to wear a wrist actigraphy for three consecutive days and nights and to fill out a sleep log each morning. The severity of depression and anxiety was evaluated according to Beck Depression Inventory and State-Trait Anxiety Inventory on the first day of the study. The subjective level of satisfaction with quality of sleep was also evaluated according to visual analog scale. Nurses assessed sleep at one hour interval between 10:00 PM and 6:00 AM for three consecutive nights. Results：There was statistically significant difference of sleep latency between patient's sleep log and acti-graphic measurement. Nursing reports were more consistent with actigraphic measurement than sleep log. Interestingly, subjectively poor sleepers show no significant difference in sleep parameters compared with those of good sleepers. Subjectively poor sleepers report longer sleep latency than that of actigraphic assessment. The discrepancy between subjective and objective assessment of sleep latency was significantly correlated with scores of Beck Depression Inventory and State-Trait Anxiety Inventory. Conclusion：These results show that there are discrepancies between subjective and objective assessment of sleep. The discrepancy of sleep assessment could be influenced by severe depression and anxiety. Especially objective sleep measurement is needed to assess sleep in psychiatric inpatients with severe depression or anxiety and the subjectively poor sleepers for more reliable measurements.

• Sleep Medicine and Psychophysiology
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• v.13 no.2
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• pp.67-74
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• 2006

Introduction: Excessive daytime sleepiness and cataplexy are key features of narcolepsy. Modafinil is psychostimulant used in the treatment of narcolepsy. In this study, we evaluated effects of modafinil on nocturnal sleep structure and sleep latency in multiple sleep latency test and clinical features. Methods: Twelve narcoleptic patients (7 male, age: $22.9{\pm}2.6\;yrs$) were participated in the study. All of them had done nocturnal polysomnography (nPSG), multiple sleep latency test (MSLT), clinical symptoms scales and have repeated same procedure after taking 200 mg of modafinil. We have done linear mixed model analysis to describe effects of group, medication and nap time on these measures. Results: Modafinil did not affect clinical scales except PSQI which had been reduced after medication. In this study, Modafinil reduced total sleep time, sleep efficiency and increased wake after sleep onset and percent of arousal during sleep in nocturnal polysomnography and prolonged mean sleep latency in multiple sleep latency tests in both group. Discussion: Modafinil has stimulant effect of central nervous system but its effect on night sleep is less than other psychostimulants such as methylphenidate. We ascertained that modafinil affected total sleep time, sleep efficiency and percent of wake during sleep but did not effect on sleep structure. Modafinil was effective in the management of day time sleepiness. Modafinil can enhance alertness of control group without day time sleepiness.