• Sleep Medicine and Psychophysiology
• /
• v.23 no.1
• /
• pp.10-15
• /
• 2016

Since its development in the early 70s, actigraphy has been widely used in sleep research and clinical sleep medicine as an assessment tool of sleep and sleep-wake cycles. The validation and reliability of actigraphic measures have been reasonably examined in healthy normal individuals with good sleep patterns. Recent literature suggests that the use of actigraphy could be further extended to monitor insomnia and circadian sleep-wake disturbances, and detect sleep changes associated with drug treatments and non-pharmacologic interventions, although it is generally recommended to use complementary assessments such as sleep diaries and overnight polysomnography when possible. The development of actigraphy includes its improved hardware sensors for better detection of movements and advanced algorithms to score sleep and wake epochs. In this paper, we briefly review the quantitative analysis methods of actigraphy and its potential applications in sleep research.

• Sleep Medicine and Psychophysiology
• /
• v.27 no.2
• /
• pp.51-55
• /
• 2020

In this paper, we reviewed domestic and foreign cases and evaluation methods for validation of sleep products for development of the domestic sleep industry. Foreign companies and organizations are trying to verify products relatively systematically for demonstration purposes, but they are using different methods depending on the institution, and standardized validation guidelines have not been established. In Korea, there has been little evaluation including objective verification for sleep products. Sleep-wake evaluation for validation of sleep products requires expert evaluation of the product and of the product effectiveness by users, and subjective and objective sleep-wake evaluations and circadian rhythm evaluation methods can be used. For more accurate verification, experimental designs such as randomization method, control product utilization method, and cross-experiment design can be used.

• Sleep Medicine and Psychophysiology
• /
• v.16 no.1
• /
• pp.5-9
• /
• 2009

Relatively little is known about the neurobiology of insomnia, despite its wide prevalence and broad medical impact. Although much is still to be learned about the pathophysiology of the disorder, identification, systematic assessment, and appropriate treatment are clearly beneficial to patients. Recent research, using quantitative EEG, polysomnography (PSG), multiple sleep latency test (MSLT) and neuroimaging techniques, suggests that some broad areas can be identified as possible pathophysiological models. Sleep-wake homeostat model hypothesizes a failure in homeostatic regulation of sleep, an attenuated increase in sleep drive with time awake, and/or defective sensing of sleep need. Circadian clock model hypothesizes a dysfunctional circadian clock, resulting in changes in the timing of sleep-wake propensity that are incompatible with normal sleep. Intrinsic sleep-wake state mechanism model suggests that abnormal function of insomnia comprises the systems responsible for expression of the sleep states themselves. Extrinsic over-ride mechanism (stress-response) model suggests that insomnia reflects the consequences of overactivity of one of the systems considered "extrinsic" to normal sleep-wake control. Many current therapies for insomnia are based on these physiological models. Several attempts have been made to create a physiological model that would explain this disorder and could be used as a foundation for treatment. However, it appeared that no model can fully explain and clarify all aspects of insomnia. Future research should be necessary to expand our knowledge on the biological dimensions of insomnia.

• Safety and Health at Work
• /
• v.10 no.3
• /
• pp.254-259
• /
• 2019

Background: This cross-sectional study assessed the sleep quality using the ActiGraph and investigated the relationship between the parameters of sleep assessment and the type of shift work in Korean firefighters. Methods: The participants were 359 firefighters: 65 day workers (control group) and 294 shift workers (shift work group: 77 firefighters with 3-day shift, 72 firefighters with 6-day shift, 65 firefighters with 9-day shift, and 80 firefighters with 21-day shift). Sleep assessments were performed using the ActiGraph (wGT3X-BT) for 24 hours during day shift (control and shift work group) and night shift and rest day (shift work group). The participants recorded bed time and sleep hours during the measurement period. Results: Sleep efficiency, total sleep time, and percentage of wake after sleep onset during night work were lower in the shift work group than control group (p < 0.05). Sleep efficiency decreased in night shift and increased in rest day, whereas wake after sleep onset increased in night shift and decreased in rest day (p < 0.05). Among shift work groups, sleep efficiency of 6-day shift was higher in day shift, and sleep efficiency of 21-day shift was lower in night shift than other shift groups (p < 0.05). Conclusion: We found that the sleep quality in night shift of the shift work group was poorer than the control group. As to the type of shift work, sleep quality was good in 6-day shift and poor in 21-day shift. Thus, fast rotating shift such as 6-day shift may be recommended to improve the sleep quality of the firefighters.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.8
• /
• pp.291-303
• /
• 2021

The purpose of this study is to identify the effects of laughter therapy on depression and sleep wake disorders among the elderly in residential facilities using a systemic review and meta-analysis. Twelve databases were searched. Two researchers independently performed the selection of the studies, data coding and assessment. The risk of bias was assessed using risk of bias (RoB) and risk of bias assessment tool for non-randomized studies (RoBANs). To estimate the effect size, meta-analysis of the studies was performed using R version 4.04. Out of the 1,122 retrieved articles, one randomized controlled trial (RCT) and eleven non-randomized controlled trials (non-RCTs) were selected for analysis. The overall effect size of eleven studies on depression was determined to be -1.04 (95% Cl: -1.53~-0.54, p<.001). There were statistically significant in the effect of below ten sessions and the effect of below 400 minutes'and 400 to 1000 minutes'interventions on depression. The overall effect size of five studies on sleep wake disorders was 0.83 (95% Cl: -0.26~1.93, p=.136), which was not statistically significant. There was statistically significant in the effect of below 300 minutes'interventions on sleep wake disorders. Laughter therapy was an effective non-pharmacological intervention to reduce depression among the elderly in residential facilities. The findings also suggest that guidelines for laughter therapy need to be developed considering the number of sessions and a duration of intervention to reduce depression and sleep wake disorders of the elderly in residential facilities.

• The Journal of Korean Academy of Sensory Integration
• /
• v.21 no.2
• /
• pp.69-83
• /
• 2023

Objective : This study sought to systematically examine the intervention effect of social stories when applied in relation to children with sleep disorders. Methods : Studies available in the SCOPUS, ScienceDirect, PsycArticles, and PubMed databases that were published from 2001 to 2022 were searched. The keywords used for the search were as follows: ("social story" OR "social stories") AND ("sleep" OR "sleep disorders" OR "sleep wake disorder bedtimes" OR "sleep initiation and maintenance disorders" OR "sleep wake disorder" OR "sleep arousal disorders"). Based on the selection criteria, six experimental studies were selected and analyzed. Results : The selected studies were two randomized controlled trials, three individual trials, and one case study. The subjects were mostly children diagnosed with autism spectrum disorder who were school-aged or adolescent. The intervention types were often complex interventions, including social stories and other interventions, while the durations of the interventions varied from one day to more than 40 days. The interventions had a positive effect on the subjects' sleep quality, with night wakings, sleep onset delay, and sleep anxiety all being improved. As standardized assessment tools to evaluate the effectiveness of social stories, the Child Sleep Habits Questionnaire and the Child Behavior Checklist were used in two papers each, and were the most commonly used. As non-standardized assessment tools, each of the four papers used turbulence and sleep diaries as assessment tools. Conclusion : The effect of social story mediation can be divided into sleep quality and sleep-related behavior. In terms of sleep quality, studies showing improvements in night wakings, sleep onset delay, and sleep anxiety accounted for a large proportion of the sample. The detailed effect area of sleep quality showed a significant improvement after the interventions in most studies, and in all six studies analyzed in the present study, the continuation of the effect after the intervention was confirmed via follow-up tests. Thus, the findings of this study are expected to be helpful when applying social stories in children with sleep disorders in clinical practice due to presenting the intervention effects, outcome evaluation tools, and intervention periods in children with sleep disorders in prior investigations involving social stories.

• Sleep Medicine and Psychophysiology
• /
• v.24 no.1
• /
• pp.5-11
• /
• 2017

The use of alcohol is associated with the development and worsening of sleep disorder. Alcohol is generally known to have a sedative effect, but it has an arousal or sedative effect depending on the timing and drinking dose and directly affects REM sleep physiology. Alcohol acts on the central nervous system (CNS) to interfere with the sleep-wake cycle and to affect sleep-related hormone secretion. In addition, the ingestion of alcohol pre-sleep is associated with deterioration and development of sleep related breathing disorders (SBD). The increase in resistance of the upper respiratory tract and the decrease in sensitivity of the CNS respiratory center and the respiratory muscles are major mechanisms of alcohol-induced SBD, and result in snoring or apnea in healthy men or aggravating apnea in patients with OSA. Sleep-related restless leg syndrome and circadian rhythm disorders are common in alcohol use disorder patients. This review provides an assessment of scientific studies that investigated on the impact of alcohol ingestion on nocturnal sleep physiology and sleep disorders.

• Research in Community and Public Health Nursing
• /
• v.31 no.4
• /
• pp.447-458
• /
• 2020

Purpose: The purpose of this study was to identify the effects of auricular acupressure therapy on sleep disorder and fatigue in menopausal women. Methods: The study design was a non-equivalent control group pretest-posttest design. The participants were 40~60 years old women, assigned to the experimental group (n=25) or the control group (n=27). Auricular acupressure using vaccaria seeds was administered to the experimental group. The sessions continued for 6 weeks. Outcome measures included Pittsburgh sleep quality index, sleep meter, sleep diary, fatigue assessment instrument, serum cortisol, and serum serotonin. Results: Menopausal women in the experimental group showed significant increases in deep sleep, light sleep, serotonin level and sleep duration compared with the control group. Also, the experimental group reported decreases in PSQI, sleep latency, awakening time, fatigue and cortisol level compared with the control group. Conclusion: Results show that auricular acupressure using vaccaria seeds is considered as an effective treatment for sleep disorder and fatigue in menopausal women. We conclude that it can be used as a nursing intervention method proven to reduce sleep disorder and fatigue in menopausal women.

• Journal of Korean Academy of Nursing
• /
• v.54 no.2
• /
• pp.139-150
• /
• 2024

Purpose: This study aimed to identify changes in sleep patterns and fatigue levels during consecutive night shifts among shift nurses and to determine the association between sleep parameters and increased fatigue levels during work. Methods: This prospective observational study employing ecological momentary assessments was conducted using data collected from 98 shift nurses working in Korean hospitals between June 2019 and February 2021. The sleep patterns were recorded using actigraphy. The participants reported their fatigue levels at the beginning and end of each night shift in real time via a mobile link. Linear mixed models were used for the analysis. Results: Nurses spent significantly less time in bed and had shorter sleep durations during consecutive night shifts than on off-duty days, whereas their wake times after sleep onset were much longer on off-duty days than on on-duty days. Fatigue levels were higher on the second and third night-shift days than on the first night-shift days. A shorter time spent in bed and asleep was associated with a greater increase in fatigue levels at the end of the shift than at the beginning. Conclusion: Nurses experience significant sleep deprivation during consecutive night shifts compared with off-duty days, and this sleep shortage is associated with a considerable increase in fatigue levels at the end of shifts. Nurse managers and administrators must ensure sufficient intershift recovery time during consecutive night shifts to increase the time spent in bed and sleeping.

• Sleep Medicine and Psychophysiology
• /
• v.26 no.1
• /
• pp.5-15
• /
• 2019

Chronotype (CT) is defined as an inter-individual difference in sleep-wake cycles and daily activities. Previous studies have suggested that this individual difference can influence our biological and psychological functioning. Literature regarding the psychometric properties and validity of CT measures are reviewed. We provide an overview of biological indicators (sleep-wake cycle, body temperature, cortisol, and melatonin) that are used for distinguishing two chronotypes: morningness (MT) and eveningness (ET). We also review the differences between CT in relation to personality traits and the occurrence of psychopathology. In addition, the methodological limitations of studies on CT are discussed. Finally, future research directions in terms of CT are proposed.