• 한국안전학회지
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• 제30권2호
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• pp.56-62
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• 2015

The purpose of this study was to identify the relationship between the index of Electrocardiography(LF/HF) and the occurrence of drowsiness driving while driving in a simulated situation. Participants were 31 undergraduate students with an experience in driving and they participated 30 minutes driving under enough sleep condition and 1 hour under the sleep deprivation condition. The Euro Truck Simulator II was used for driving simulation task and ECG and perceived drowsiness of each participants were measured during two driving conditions. Perceived sleepiness recorded by the checklist every 10 minutes and ECG data extracted before and after 15 seconds of every 10 minutes to verify the relationship between two variables. The results showed that the level of perceived sleepiness under sleep deprivation condition was higher than that under the enough sleep condition, and the level of LF/HF under sleep deprivation condition was lower than that under the enough sleep condition. In addition, the result of analysis of repeated measure ANOVA for ECG indicated that authentic sleepiness revealed in 20 minutes after the start of driving under the sleep deprivation condition. However, the result of perceived drowsiness indicated that authentic sleepiness revealed in 30 minutes after the start of driving. These result suggest that the time difference between biological and perceived response on drowsiness may be exist. Finally, the significant negative correlation between the LF/HF level and perceived drowsiness was observed. These findings suggest that ECG(LF/HF) can be an possible index to measure drowsiness driving.

• 대한한방소아과학회지
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• 제24권3호
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• pp.106-120
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• 2010

Objectives: Sanjointang has been clinically used much for treating sleeplessness. However, the effects of Sanjointang in artificial sleep deprivation situations are not known. The purpose of this study is to evaluate the heart rate, left ventricular systolic pressure, left ventricular diastolic pressure, +dp/dt maximum, -dp/dt maximum, and -dp/dt / +dp/dt ratio which are related to the hemodynamic functions of the heart by using sleep-deprived Sparague-Dawley rats, in order to clarify the impact of Sanjointang on hemodynamic functions of the heart of sleep deprived rats. Methods: Eighteen hearts were removed from the male Sparague-Dawley rats weighting about 180g were perfused by the Langendorff technique with modified 37 Krebs-Henseleit's buffer solution at a constant perfusion pressure (60mmHg). They were randomly assigned to one of the following three groups, 1) Normal group (those which did not have sleep deprivation and received normal saline administration), 2) Control group (sleep deprived and normal saline administered), 3) Sample group (sleep deprived and Sanjointang was administered). Control and sample groups rats were deprived 96 hours of sleep by using the modified multiple platform technique. Heart rate, left ventricular systolic pressure, left ventricular diastolic pressure, +dp/dt maximum, -dp/dt maximum, -dp/dt / +dp/dt ratio were evaluated at baseline after the administration of either normal saline or Sanjointang. Results: The heart rate and -dp/dt / +dp/dt ratio was significantly decreased in rats with 96 hours of sleep deprived significantly decreased. The change in the heart rate after administering Sanjointang did not show any significant difference. The left ventricular systolic pressure of the removed heart significantly decreased due to Sanjointang administration, while the left ventricular diastolic pressure significantly increased (p<0.05). The +dp/dt maximum and -dp/dt maximum both significantly decreased in the removed heart after administering Sanjointang. (p<0.05). There was no significant difference observed in the -dp/dt / +dp/dt ratio after administering Sanjointang. Conclusions: According to the results above, sleep deprivation significantly decreases heart rate and -dp/dt / +dp/dt ratio. This is considered as a result of exhaustion due to accumulation of fatigue. Meanwhile, Sanjointang reduced left ventricular systolic pressure and raised left ventricular diastolic pressure, and relieved the contractility and relaxation of the myocardium. Consequently, this reduces the burden of the heart and creates a relatively stabilized heart condition similar to a sleeping condition.

• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.415-425
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• 2022

Memory formation in the hippocampus is formed and maintained by circadian clock genes during sleep. Sleep deprivation (SD) can lead to memory impairment and neuroinflammation, and there remains no effective pharmacological treatment for these effects. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. In this study, we investigated the effects of MYR on memory impairment, neuroinflammation, and neurotrophic factors in sleep-deprived rats. We analyzed SD-induced cognitive and spatial memory, as well as pro-inflammatory cytokine levels during SD. SD model rats were intraperitoneally injected with 10 and 20 mg/kg/day MYR for 14 days. MYR administration significantly ameliorated SD-induced cognitive and spatial memory deficits; it also attenuated the SD-induced inflammatory response associated with nuclear factor kappa B activation in the hippocampus. In addition, MYR enhanced the mRNA expression of brain-derived neurotropic factor (BDNF) in the hippocampus. Our results showed that MYR improved memory impairment by means of anti-inflammatory activity and appropriate regulation of BDNF expression. Our findings suggest that MYR is a potential functional ingredient that protects cognitive function from SD.

• Clinical and Experimental Pediatrics
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• 제54권1호
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• pp.29-35
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• 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.

• 수면정신생리
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• 제8권2호
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• pp.129-137
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• 2001

목 적 : 일상생활에서 하루 밤의 수면박탈은 흔히 있을 수 있다. 저자들은 전산화 신경인지검사를 통하여 38시간의 수면 박탈이 상지의 미세 운동수행능력에 어떠한 변화를 주는지를 연구하고자 하였다. 방 법 : 고려대학교 의과대학에 재학중인 학생중 정신적, 신체적으로 건강한 지원자 24명(M:F=21:3, mean age : $24.67{\pm}1.37$)을 대상으로 하였으며 모두 오른 손잡이었다. 또한 수면일지를 작성하게 하여 평소에 수면부족을 보이는 군은 배제하였다. Vienna Test System에서 나타날 수 있는 학습효과를 최소화하기 위하여 검사 하루 전에 미리 같은 검사를 시행하였다. 검사 전날 밤에 피험자들은 충분한 수면을 취하였으며, 검사 당일 오전 6시경에 기상하였다. 실험 첫날 오전 6시부터 다음날 오후 8시까지 38시간동안 수면을 박탈하였으며, 검사 첫날과 둘째 날의 오전 7시와 오후 7시, 총 4차례 Vienna Test System중 Motor Performance Series를 시행하였다. 실험기간 중에 모든 피험자에게 수면에 영향을 줄 수 있는 약물의 복용은 금지되었으며, 과도한 운동도 금지되었다. 자료는 SPSS를 이용하여 피험자당 4회 시행한 검사 결과를 Repeated ANOVA를 시행하였으며, 일중리듬을 고려하여 각 아침, 저녁 session끼리의 검사 결과를 paired t-test를 시행하여서 비교하였다. 결 과 : Motor Performance Series에서 수면박탈에 따라서 상지의 오른손의 운동 기능에 있어 수행능력의 저하가 나타났다. 각 소검사를 보면 tapping의 total number(p<.005), line tracking의 number of misses(p<.05), length of misses (p<.05), inserting short pin의 total length(p<.01), inserting long pin의 total length(p<.05), aiming의 number of misses (p<.05)에서 통계적으로 유의미한 기능의 저하가 나타났다. 결 론 : 이상의 결과는 38시간의 수면박탈만으로도 유의미한 운동기능의 저하가 나타난다는 것을 보여준 것이며, 특히 가장 예민하게 미세 운동기능을 발휘할 수 있는 우세한 오른손에서 기능저하가 나타났다. Inserting long pin보다는 inserting short pin 검사에서 기능이 저하되었고, line tracking, aiming에서 검사 결과의 수행 저하가 두드러진 것으로 보아서, 미세한 운동기능일수록 영향을 많이 받는다고 할 수 있겠으며, line tracking에서 전체 검사 시간은 감소되며, 수행에서 실수가 늘어난 것으로 보아, 수면박탈에 따라서 조급한 수행이 이루어진다고 보여진다. 또한 주어진 32초간의 시간 안에 최대한의 속도로 펜을 두드리는 tapping 검사에서 두드러진 저하를 보인 점에서, 수면박탈에 의하여 근육의 피로가 쉽게 나타난다고 생각 할 수 있겠다.

• 전자공학회논문지SC
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• 제47권2호
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• pp.43-49
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• 2010

자율신경계는 불수의적 활동 기능을 조절해 주는 신경계통으로, 자율신경계의 활성 정도를 정량적으로 평가하기 위해 심박 변이도가 이용된다. 그러나 심박 변이도는 환경 변화나 심리 상태의 변화 등에 민감하게 반응하며, 자세와 수면 박탈에 의해서도 심박 변이도가 달라질 수 있다. 특히 전자파 자원자 연구에서는 자각 증상 및 인지 여부에 의한 수면 박탈로 심박 변이도가 달라질 수 있다. 이에 본 연구에서는 자세에 따른 수면 박탈 횟수와 심박 변이도를 30분간 6 stage에서 측정하였고, 앉은 자세와 누운 자세에서 측정된 심박 변이도를 비교하여 앉은 자세나 누운 자세에서 심박 변이도를 측정하는 실험에 어떠한 자세가 적합한지 결정하고자 하였다. 심박 변이도 분석은 전력 스펙트럼을 이용한 주파수 영역에서의 LF (low frequency) / HF(high frequency)를 이용하였고, stage 1을 100%로 하여 개인 및 성별에 따른 초기 LF/HF 차이를 상쇄시켜 주었다. LF/HF 증가는 교감 신경의 활성 증가를 나타내고 감소는 교감 신경의 활성 감소를 나타낸다. 교차 분석 결과 수면 박탈은 자세의 영향을 받는 것으로 나타났으며 (p=0.002), LF/HF에 대하여 자세만을 변수로 고려하였다. 앉은 자세에서 수면 박탈 횟수는 모든 stage에서 누운 자세보다 유의하게 적었다 (p<0.05). 자세는 LF/HF에 유의한 영향을 끼쳤으며 (p=0.033), 앉은 자세에서는 stage 1과 비교하여 LF/HF가 stage 4, 5, 6에서 유의하게 증가하였고 (p<0.05), 누운 자세에서는 stage 1과 비교하여 모든 stage에서 LF/HF가 유의하게 증가하였다 (p<0.05). 따라서 앉은 자세가 누운 자세보다 수면 박탈 횟수가 적고 LF/HF 변화가 작기 때문에 피험자가 깨어 있어야 하는 심박 변이도 측정 실험에 있어서 더 적합한 자세라고 사료된다.

• 대한간호학회지
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• 제54권2호
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• pp.139-150
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• 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.

• The Korean Journal of Physiology and Pharmacology
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• 제14권5호
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• pp.291-297
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• 2010

The sleep homeostatic response significantly affects the state of anesthesia. In addition, sleep recovery may occur during anesthesia, either via a natural sleep-like process to occur or via a direct restorative effect. Little is known about the effects of isoflurane anesthesia on sleep homeostasis. We investigated whether 1) isoflurane anesthesia could provide a sleep-like process, and 2) the depth of anesthesia could differently affect the post-anesthesia sleep response. Nine rats were treated for 2 hours with $ad$ $libitum$ sleep (Control), sleep deprivation (SD), and isoflurane anesthesia with delta-wave- predominant state (ISO-1) or burst suppression pattern-predominant state (ISO-2) with at least a 1-week interval. Electroencephalogram and electromyogram were recorded and sleep-wake architecture was evaluated for 4 hours after each treatment. In the post-treatment period, the duration of transition to slow-wave-sleep decreased but slow wave sleep (SWS) increased in the SD group, but no sleep stages were significantly changed in ISO-1 and ISO-2 groups compared to Control. Different levels of anesthesia did not significantly affect the post-anesthesia sleep responses, but the deep level of anesthesia significantly delayed the latency to sleep compared to Control. The present results indicate that a natural sleep-like process likely occurs during isoflurane anesthesia and that the post-anesthesia sleep response occurs irrespective to the level of anesthesia.

• The Korean Journal of Physiology and Pharmacology
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• 제26권5호
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• pp.297-305
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• 2022

The presence of artificial light enables humans to be active 24 h a day. Many people across the globe live in a social culture that encourages staying up late to meet the demands of various activities, such as work and school. Sleep deprivation (SD) is a severe health problem in modern society. Meanwhile, as with cardiometabolic disease, there was an obvious tendency that coronary heart disease (CHD) to become a global epidemic chronic disease. Specifically, SD can significantly increase the morbidity and mortality of CHD. However, the underlying mechanisms responsible for the effects of SD on CHD are multilayered and complex. Inflammatory response, lipid metabolism, oxidative stress, and endothelial function all contribute to cardiovascular lesions. In this review, the effects of SD on CHD development are summarized, and SD-related pathogenesis of coronary artery lesions is discussed. In general, early assessment of SD played a vital role in preventing the harmful consequences of CHD.

• 수면정신생리
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• 제5권1호
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• pp.18-33
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• 1998

Sleep and Epilepsy either represent the opposite and independent spectrum of episodic manifestations from brain or closely interact with each other. Sleep or sleep deprivation may provoke epileptic seizures or activate epileptiform discharges in epilepsy patients whereas epilepsy may alter the sleep structure. Sleep stages are also known to influence pathophysiology of seizures in terms of ictogenesis. In this review, the impact of sleep on epilepsy as well as that of epilepsy on sleep are presented. Additionally the interaction between sleep and epilepsy will be discussed. This review will also comment on the differential diagnosis between nocturnal or sleep-related epilepsy and various sleep disorders. Finally, clinical application of the above perspectives of sleep and epilepsy will be suggested for the purpose of a better management of epilepsies.