• Sleep Medicine and Psychophysiology
• /
• v.16 no.1
• /
• pp.16-21
• /
• 2009

In accordance with the development of EEG and polysomnography in the field of sleep research, the sleep onset period (SOP) between wakefulness and sleep has been considered an important part for understanding the physiology of sleep. SOP in the transition from wakefulness to sleep is a gradual process integrating various viewpoints such as behavior, EEG, physiology and subjective report. Particularly, based on understanding of EEG changes during sleep, SOP has been regarded as a pattern of topographical change in specific frequency and specific state in EEG. Studies on quantitative EEG (qEEG) and event-related potential (ERP) have suggested that SOP shows the changes of functional coordination at the specific cortical areas in qEEG and the changes of regular patterns in response to environmental stimulation in ERP. The development of sleep EEG and topographic mapping of EEG is expected to integrate various viewpoints of SOP and clarify the neurophysiologic mechanism of SOP further.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.1 no.1
• /
• pp.19-35
• /
• 1994

To test the effectiveness of the preparatory audiovisual information with videotape, 34 patients with gastric cancer and who have scheduled for subtotal gastrectomy were studied with quasiexperimental research design. The subjects were selected from the 4 general surgical wards of one university hospital in Seoul, and assigned to experimental and control group conveniently. The videotaped information on the preparation and recovery for surgery was showed to the experimental subjects once before having operation. Data on the sleep and the state anxiety level before and after treatment day was collected with VSH sleep scale and STAI. The data was analyzed with t-test to test the effect of preparatory information and the Pearson's correlation to identify the correlation between anxiety and sleep. The results were summerized as follows : 1. After receiving the preparatory information, the level of anxiety of the experimental group was the same level as the initial, whereas that of the control group showed markedly increase. However no significant difference in anxiety between the two groups was found. 2. There was significant difference in sleep score between the experimental and the control group. 3. There was significant negative correlation between the state anxiety score and the sleep score. Based upon the above findings, this study concludes that preparatory information is effective to enhance sleep just prior to the surgery.

• Sleep Medicine and Psychophysiology
• /
• v.11 no.1
• /
• pp.10-16
• /
• 2004

Sleep is associated with definite changes in respiratory function in normal human beings. During sleep, there is loss of voluntary control of breathing and a decrease in the usual ventilatory response to both low oxygen and high carbon dioxide levels. Especially, rapid eye movement (REM) sleep is a distinct neurophysiological state associated with significant changes in breathing pattern and ventilatory control as compared with both wakefulness and non-rapid eye movement (NREM) sleep. REM sleep is characterized by erratic, shallow breathing with irregularities both in amplitude and frequency owing to marked reduction in intercostal and upper airway muscle activity. These blunted ventilatory responses during sleep are clinically important. They permit marked hypoxemia that occurs during REM sleep in patients with lung or chest wall disease. In addition, sleep-disordered breathing (SDB) is more frequent and longer and hypoventilation is more pronounced during REM sleep. Although apneic episodes are most frequent and severe during REM sleep, most adults spend less than 20 to 25% of total sleep time in REM sleep. It is, therefore, possible for patients to have frequent apneas and hypopneas during REM sleep and still have a normal apnea-hypopnea index if the event-rich REM periods are diluted by event-poor periods of NREM sleep. In this review, we address respiratory physiology according to sleep stage, and the clinical implications of SDB and hypoventilation aggravated during REM sleep.

• Sleep Medicine and Psychophysiology
• /
• v.10 no.2
• /
• pp.77-83
• /
• 2003

Industrialization has brought great changes in human life. Human sleep patterns have also been much influenced by industrialization and the invention of electricity and the light bulb. Insufficient sleep is a common problem with considerable health, social, and economical impacts on modern society. In this review, we will outline the present state of insufficient sleep in our society, especially catastrophic accidents related with chronic sleep insufficiency. We will discuss the effect of sleep deprivation on human performance by reviewing the literature. We will also emphasize the role of sleep specialists in this issue and highlight the areas in which the principles of sleep medicine can constructively improve public policy and public health.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.18
• /
• pp.8127-8133
• /
• 2016

Background: The objective of this study was to evaluate the effect of back massage on the anxiety state, cortisol level, systolic/diastolic blood pressure, pulse rate, and sleep quality in family caregivers of patients with cancer. Materials and Methods: Forty-four family caregivers were randomly assigned to either the experimental or control group (22 interventions, 22 controls) after they were matched on age and gender. The intervention consisted of back massage for 15 minutes per day for a week. Main research outcomes were measured at baseline (day I) and follow-up (day 7). Unpaired t-test, paired t test and chi-square test were used to analyse data. Results: The majority of the caregivers were women, married, secondary school educated and housewife. State anxiety (p<0.001), cortisol level (p<0.05), systolic/diastolic blood pressure (p<0.001, p<0.01 respectively), and pulse rate (p<0.01) were significantly decreased, and sleep quality (p<0.001) increased after back massage intervention. Conclusions: The study results show that family caregivers for patients with cancer can benefit from back massage to improve state anxiety, cortisol level, blood pressure and heart rate, and sleep quality. Oncology nurses can take advantage of back massage, which is non-pharmacologic and easily implemented method, as an independent nursing action to support caregivers for patients with cancer.

• Sleep Medicine and Psychophysiology
• /
• v.2 no.2
• /
• pp.133-137
• /
• 1995

The author reviews current knowledge about what REM sleep is and where and how it is generated. REM sleep is the state in which our most vivid dreams occur. REM sleep is identified by the simultaneous presence of a desynchronized cortical EEG, an absence of activity in the antigravity muscles(atonia), and periodic bursts of rapid eye movements. Another characteristic phenomena of REM sleep are the highly synchronized hippocampal EEG of theta frequency and the ponto-geniculo-occipital(PGO) spike. All these phenomena can be explained in terms of changes in neuronal activity. Transection studies have determined that the pons is sufficient for generating REM sleep. Lesion studies have identified a small region in the lateral pontine tegmentum corresponding to lateral portions of the nucleus reticularis pontis oralis(RPO) and the region immediately ventral to the locus coeruleus, which is required for REM sleep. Unit recording studies have found a population of cells within this region that is selectively active in REM sleep. Cholinergic neurons of the giant cell field of pontine tegmentum(ETG), which is 'REM a sleep-on cells', has shown to be critically involved in the generation of REM sleep. Noradrenergic neurons of the locus coeruleus and serotonergic neurons of the dorsal raphe, which are called 'REM sleep-off cells', appear to act in a reciprocal manner to the cholinergic neurons. It is proposed that the periodic cessations of discharge of 'REM sleep-off cells' during REM sleep might be significant for the prevention of the desensitization of receptors of these neurons.

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

• Clinical and Experimental Pediatrics
• /
• v.54 no.1
• /
• pp.29-35
• /
• 2011

Purpose: Korean adolescents have severe nighttime sleep deprivation and daytime sleepiness because of their competitive educational environment. However, daytime sleep patterns and sleepiness have never been studied using age-specific methods, such as the pediatric daytime sleepiness scale (PDSS). We surveyed the daytime sleepiness of Korean adolescents using a Korean translation of the PDSS. Methods: We distributed the 27-item questionnaire, including the PDSS and questions related to sleep pattern, sleep satisfaction, and emotional state, to 3,370 students in grades 5-12. Results: The amount of nighttime sleep decreased significantly with increasing age. During weekday nights, $5-6^{th}$ graders slept for $7.95{\pm}1.05h$, $7-9^{th}$ graders for $7.57{\pm}1.05h$, and $10-12^{th}$ graders for $5.78{\pm}1.13h$. However, the total amounts of combined daytime and nighttime sleep during weekdays were somewhat greater, $8.15{\pm}1.12h$ for $5-6^{th}$ graders, $8.17{\pm}1.20h$ for $7-9^{th}$ graders, and $6.87{\pm}1.40h$ for $10-12^{th}$ graders. PDSS scores increased with age, $11.89{\pm}5.56$ for $5-6^{th}$ graders, $16.57{\pm}5.57$ for $7-9^{th}$ graders, and $17.71{\pm}5.24$ for $10-12^{th}$ graders. Higher PDSS scores were positively correlated with poor school performance and emotional instability. Conclusion: Korean teenagers sleep to an unusual extent during the day because of nighttime sleep deprivation. This negatively affects school performance and emotional stability. A Korean translation of the PDSS was effective in evaluating the severity of daytime sleepiness and assessing the emotional state and school performance of Korean teenagers.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.4
• /
• pp.1359-1375
• /
• 2015

Energy efficiency is critical for Wireless Sensor Networks (WSNs) since sensor nodes usually have very limited energy supply from battery. Sleep scheduling and nodes cooperation are two of the most efficient methods to achieve energy conservation in WSNs. In this paper, we propose an adaptive energy optimization approach for target tracking applications, called Energy-Efficient Node Coordination (EENC), which is based on the grid structure. EENC provides an unambiguous calculation and analysis for optimal the nodes cooperation theoretically. In EENC, the sleep schedule of sensor nodes is locally synchronized and globally unsynchronized. Locally in each grid, the sleep schedule of all nodes is synchronized by the grid head, while globally the sleep schedule of each grid is independent and is determined by the proposed scheme. For dynamic sleep scheduling in tracking state we propose a multi-level coordination algorithm to find an optimal nodes cooperation of the network to maximize the energy conservation while preserving the tracking performance. Experimental results show that EENC can achieve energy saving of at least 38.2% compared to state-of-the-art approaches.

• Sleep Medicine and Psychophysiology
• /
• v.2 no.2
• /
• pp.138-145
• /
• 1995

The causes of complicated chronic insomnia are very various and interact with vicious circle. Patient with this insomnia has generally a strong fear and frustration about failing to control of sleep and a deep mistrust toward doctor. To solve this complicated problems detailed history taking and sleep questionnaires are needed with objective polysomnography. Through these procedures, doctor should clarify causes of insomnia and explain them to patient in details and kindly. This process would be very helpful to restore the mistrustful relationship between patient and doctor and reduce patient's vague fear for insomnia. In treatment of complicated chronic insomnia, it is most important for patient to understand his problems and participate in the treatment schedule actively with assurance. Also doctor should encourage patient persistently not to be drop out. Most important factor for prognosis is patient's personality. Causes of complicated chronic insomnia are like these, overdose of hypnotics and sedatives, daily drinking alcohol with hypnotics, insomnia associated depression, delayed sleep phase syndrome, sleep state misperception, marked fear for insomnia, hyperarousal at bed, insomnia associated periodic leg movement and sleep apnea, chronic hypnotic insomnia, and immature personality. And possible treatments of these insomnias were discussed.