Duration Of Deep Sleep Research Articles

The Effect of Water-Soluble Alpinia Galanga Extract on Sleep and the Activation of the GABAAergic/Serotonergic Pathway in Mice

Background/Objectives: With increasing interest in plant-based compounds that can enhance sleep quality without the side effects of caffeine, Alpinia galanga (AG) has emerged as a promising herbal supplement for improving mental alertness. This study assessed the impact of water-soluble AG extract on sleep quality; the activity of GABAergic, glutamatergic, and serotonergic receptors; and concentrations of dopamine and serotonin in the brains of mice. Methods: The study employed two experimental models using BALB/c mice to examine the impact of pentobarbital-induced sleep and caffeine-induced insomnia. In the first model, a set of 20 mice was assigned to four groups to assess the effects of pentobarbital (42 mg/kg) or pentobarbital with AG extract on sleep induction, with observations made 45 min post-administration. In the second model, 20 mice were divided into four groups to evaluate the impact of caffeine (25 mg/kg) alone or caffeine with varying doses of AG extract (61.25 or 205.50 mg/kg administered orally) on brain activity along with additional analyses on receptor proteins and neurotransmitters. Results: A higher dose of AG extract (205.50 mg/kg) significantly increased total deep sleep duration compared to the caffeine group (p < 0.0001). Furthermore, this dose extended sleep latency and suppressed GABAergic and glutamatergic receptor activity compared to the lower AG dose (p < 0.05). Additionally, the 205.50 mg/kg dose elevated serotonin and dopamine levels compared to caffeine (p < 0.0001), suggesting improved sleep quality alongside enhanced wakefulness. Conclusions: Our data indicate that a higher dose of AG extract improved sleep latency and duration by regulating GABAergic and glutamatergic receptors through the GABAergic/serotonergic pathway in mice.

Magnetic Garments Promote Parasympathetic Dominance and Improve Sleep Quality in Male Long-Distance Runners Following a 30 km Run.

This study aimed to investigate the effects of high-intensity running on the autonomic nervous system and sleep quality of male long-distance runners and to examine the impact of wearing magnetic garments on these parameters. Fifteen highly trained male collegiate long-distance runners participated in a randomized, double-blind crossover study. Participants completed two 30 km runs (30k-RUN) during a 10-day training camp. After each run, they wore either magnetic (MAG) or non-magnetic control (CTRL) garments. Sleep quality and heart rate variability (HRV) were assessed using a wrist-worn device before and after each 30k-RUN. Wearing MAG garments post-30k-RUN resulted in significantly longer deep sleep duration compared to CTRL. HRV analysis revealed that the MAG condition led to a significantly higher root mean square of successive RR interval differences and high-frequency power, indicating enhanced parasympathetic activity. The low-frequency to high-frequency ratio was significantly lower in MAG than in CTRL. Perceived recovery scores were significantly higher in MAG than in CTRL. The findings of this study suggest that wearing magnetic garments following high-intensity endurance running may promote parasympathetic dominance and improve sleep quality in male long-distance runners. These findings indicate that magnetic garments may be a practical method for enhancing recovery in athletes following intense training.

Association of Sleep Patterns and Respiratory Disturbance Index with Physiological Parameters in Pediatric Patients with Self-Perceived Short Stature.

To investigate the relationships of sleep patterns and respiratory disturbance index (RDI) with key physiological parameters (height, body mass index (BMI), bone age (BA), and IGF-1 levels) in children aged 6 to 16 years with self-perceived short stature. For this cross-sectional study, conducted from October 2019 to November 2021, 238 children aged 6 to 16 years with self-perceived short stature were enrolled. The primary outcomes of sleep patterns and the RDI were non-invasively collected at home using the LARGAN Health AI-Tech Sleep Apnea and Sleep Quality Examination System, which operates based on polygraphy. Additionally, various physiological parameters, including height, BMI, bone age, and IGF-1 levels, were measured to assess their associations with sleep patterns and RDI. Significant age-related reductions were observed in both the total and deep sleep durations. Children aged 6-9 years averaged 8.5 ± 1.0 h of total sleep, which decreased to 8.1 ± 1.1 h in ages 10-11 and further to 7.5 ± 0.9 h in ages 12-16 (p < 0.0001). Deep sleep followed a similar pattern, decreasing from 4.4 ± 1.1 h in the youngest group to 3.3 ± 1.0 h in the oldest (p < 0.0001). Notably, girls experienced significantly longer deep sleep than boys, averaging 4.0 ± 1.2 h compared to 3.6 ± 1.2 h (p = 0.0153). In a multivariable regression analysis, age (beta = 4.89, p < 0.0001) and RDI (beta = -0.54, p = 0.0022) were significantly associated with body height. Age and deep sleep duration (beta = -0.02, p = 0.0371) were significantly associated with BMI. The results demonstrate significant age-related decreases in the total and deep sleep duration among children with self-perceived short stature, along with a notable association between RDI and body height and an association between deep sleep duration and BMI. These findings suggest that sleep disturbances in pediatric endocrine patients are intricately linked with physiological growth parameters. The identified correlations underline the importance of monitoring sleep patterns in this demographic to better understand the impact of endocrine disorders on developmental health. Further research is needed to explore interventions that could alleviate these sleep disturbances, thereby potentially improving outcomes for the affected children.

Multi-Sensory Stimuli Improve Relaxation and Sleep Quality in Rotating Shift Workers: A Randomized Controlled Trial.

To compare the effects of multi-sensory stimuli on relaxation and sleep quality in 2 periods. This experimental research used a sample group of 60 individuals, divided into three groups, with each group consisting of 20 participants. The test period was divided into two equal periods of 4 days each. The collected data included measurements of relaxation (visually calibrated scale, percentage stress, and heart rate) and sleep quality (percentage sleep, total sleep duration, and duration of deep sleep). Quantitative statistics were employed to analyze the data and compare average differences. Regarding relaxation, the results from the second period test indicated that Group 2, which received both fragrance and natural sound treatment, outperformed the other groups based on the visually calibrated scale. This group also exhibited lower levels of percentage stress and heart rate as compared to Group 1 and the control group, with a confidence level of p < 0.05. In terms of sleep quality, during the second period test, Group 2 achieved more superior results compared to the other groups in terms of percentage sleep, total sleep duration, and duration of deep sleep, with a confidence level of p < 0.05. It can be inferred that multi-sensory stimuli enhanced relaxation and sleep quality.

Effectiveness of a proprietary Dichrostachys glomerata extract (DYG-400®) on Adult's Sleep Quality and Activity: A Pilot Trial

Objectives: The purpose of this study was to examine the effectiveness of Dichrostachys glomerata (Dyglomera®) supplementation on adults’ sleep quality and daytime activity. Methods: Using a double-blind placebo-controlled pilot trial, 56 adults with nonclinical poor sleep (M age = 44.50) were randomized to either the Dichrostachys glomerata Group (300 mg/d) or Placebo Group for 60 days. Outcomes were the self-reported Insomnia Severity Index and objective sleep and daytime activity via the Oura Ring. Analysis was undertaken at Day 0 (Baseline), Day 30, and Day 60. Results: The Dichrostachys glomerata Group had improved Insomnia Severity Index symptoms, with significant improvements from Day 0 to Day 60. Objective sleep measures indicated that the Dichrostachys glomerata Group had significantly improved sleep score and deep sleep duration, while the Placebo Group declined in these parameters. The Dichrostachys glomerata Group also improved on sleep latency and time awake, contrasting with worsened of these sleep metrics in the Placebo Group, p’s &lt; .05. No group differences were found for REM. The Dichrostachys glomerata Group improved significantly on the activity outcomes. Conclusion: These results provide preliminary support for the potential of Dichrostachys glomerata supplementation to enhance both sleep and daytime activity. Further research is warranted to validate these findings in diverse populations. Clinical trial registry = ISRCTN10099861.

Effects of Tobacco Use on the Macrostructure and Microstructure of Sleep in Patients with OSA.

Both tobacco use and obstructive apnea-hypopnea syndrome (OSA) can affect sleep, and it is speculated that tobacco use may further affect the sleep of those with OSA. Our primary objective is to clarify the associations between tobacco use and the macrostructure and microstructure of sleep in patients with OSA. This retrospective study encompasses a cohort of 1017 patients who were hospitalized between January 2020 and January 2023 for the investigation of sleep disorders. Rigorous inclusion criteria were applied, and all patients underwent a comprehensive polysomnography (PSG) assessment and completed a Pittsburgh Sleep Quality Index (PSQI) questionnaire. Patients with OSA who concurrently used tobacco exhibited markedly inferior sleep quality than those who did not. Notably, there was no association between the degree of tobacco dependence and sleep quality. Those with OSA who used tobacco demonstrated a significant prolongation of stage 1 light sleep and a reduction of deep sleep duration (N3). In this group, those who demonstrated poor sleep quality had more pronounced alterations in light sleep stages with prolonged N1 and shortened N2 stages. Our findings reveal a substantial reduction in sleep quality amongst OSA patients who also use tobacco, compared to those with OSA who do not use tobacco. The rate of poor sleep quality was not linearly associated with the level of tobacco dependence. Tobacco use was associated with alterations in both light and slow wave sleep in those with OSA. Importantly, the effects of tobacco dependence on sleep structure were more pronounced in those with more severe OSA.

앙상블 머신러닝 모델을 활용한 치매 예측

As we become an aging society, there is a growing concern about geriatric diseases. Among them, senile dementia, which disrupts daily life, is best detected at an early stage because there is no cure, even with technological advances. However, many preliminary studies to predict dementia require continuous imaging data, such as MRI and retinal imaging data, and are expensive. These methods have the disadvantage that they cannot be applied to all people, so this study aims to develop low-cost predictive dementia detection. Therefore, the purpose of this study is to identify the main variables that most influenced the presence of dementia using deep learning prediction models such as XGBsoot and lightGBM by utilizing various activity data such as exercise duration, high-intensity activity duration, and metabolic rate, and sleep data such as deep sleep duration and breathing rate per minute to determine sleep quality. The analysis showed that the best dementia prediction performance was achieved when both activity and sleep data were considered simultaneously, and the most important variable in the XGBoost model was the “activity_score_move_every_hour” and the “sleep_hr_everage” in lightGBM.

Ventilation causing an average CO2 concentration of 1,000 ppm negatively affects sleep: A field-lab study on healthy young people

Poor bedroom ventilation, leading to poor indoor air quality (IAQ), has been shown to reduce sleep quality. Ventilation causing a carbon dioxide (CO2) concentration of 1,000 ppm is assumed to permit optimal sleep quality. The effects of three ventilation levels causing average indoor CO2 concentrations of 750 ppm, 1,000 ppm and 1,300 ppm, on sleep quality, physiological response and next-day work performance were examined. After a first night for adaptation, thirty-six young and healthy participants slept alone in simulated bedrooms for two nights at each of the three ventilation levels in balanced order. Sleep quality was recorded by a wrist-worn sleep tracker. Physiological parameters were measured before sleep and after waking. The participants’ ratings of the bedroom environment, the intensity of the health symptoms they experienced, and cognitive performance were obtained using questionnaires and tests.Compared with ventilation causing an average CO2 concentration of 750 ppm, sleep quality was significantly reduced at the ventilation rates causing CO2 concentrations of 1,000 ppm and 1,300 ppm: Sleep efficiency was reduced by 1.3 % and 1.8 % and time awake increased by 5.0 min and 7.8 min, respectively. Deep sleep duration decreased at the ventilation rate causing CO2 concentration of 1,300 ppm as compared to 750 ppm along with a significant increase in salivary cortisol after waking, which suggests increased stress and sympathetic activity. Ventilation causing an average CO2 concentration of 1,000 ppm or above in bedrooms should therefore be avoided. Participants whose sleep quality was poorer performed worse on tests of cognitive performance the next day.

Impact of Preoperative Sleep Disturbances on Postoperative Delirium in Patients with Intracranial Tumors: A Prospective, Observational, Cohort Study.

Postoperative delirium (POD) is prevalent in craniotomy patients and is associated with high mortality. Sleep disturbances are receiving increasing attention from clinicians as associated risk factors for postoperative complications. This study aimed to determine the impact of preoperative sleep disturbances on POD in craniotomy patients. We recruited 130 patients undergoing elective craniotomy for intracranial tumors between May 1st and December 30th, 2022. Preoperative subjective sleep disturbances were assessed using the Pittsburgh Sleep Quality Index on the day of admission. We also measured objective perioperative sleep patterns using a dedicated sleep monitoring device 3 days before and 3 days after the surgery. POD was assessed twice daily using the Confusion Assessment Model for the Intensive Care Unit within the first week after craniotomy. Preoperative sleep disturbances were diagnosed in 49% of the study patients, and POD was diagnosed in 22% of all the study patients. Sleep disturbances were an independent risk factor for POD (OR: 2.709, 95% CI: 1.020-7.192, P = 0.045). Other risk factors for POD were age (OR: 3.038, 95% CI: 1.195-7.719, P = 0.020) and the duration of urinary catheterization (OR: 1.246, 95% CI: 1.025-1.513, P = 0.027). Perioperative sleep patterns (including sleep latency, deep sleep duration, frequency of awakenings, apnea-hypopnea index, and sleep efficiency) were significantly associated with POD. This study demonstrated that preoperative sleep disturbances predispose patients undergoing craniotomy to POD, also inferred a correlation between perioperative sleep patterns and POD. The targeted screening and intervention specifically for sleep disturbances during the perioperative period are immensely required.

Three Contactless Sleep Technologies Compared With Actigraphy and Polysomnography in a Heterogeneous Group of Older Men and Women in a Model of Mild Sleep Disturbance: Sleep Laboratory Study.

Contactless sleep technologies (CSTs) hold promise for longitudinal, unobtrusive sleep monitoring in the community and at scale. They may be particularly useful in older populations wherein sleep disturbance, which may be indicative of the deterioration of physical and mental health, is highly prevalent. However, few CSTs have been evaluated in older people. This study evaluated the performance of 3 CSTs compared to polysomnography (PSG) and actigraphy in an older population. Overall, 35 older men and women (age: mean 70.8, SD 4.9 y; women: n=14, 40%), several of whom had comorbidities, including sleep apnea, participated in the study. Sleep was recorded simultaneously using a bedside radar (Somnofy [Vital Things]: n=17), 2 undermattress devices (Withings sleep analyzer [WSA; Withings Inc]: n=35; Emfit-QS [Emfit; Emfit Ltd]: n=17), PSG (n=35), and actigraphy (Actiwatch Spectrum [Philips Respironics]: n=18) during the first night in a 10-hour time-in-bed protocol conducted in a sleep laboratory. The devices were evaluated through performance metrics for summary measures and epoch-by-epoch classification. PSG served as the gold standard. The protocol induced mild sleep disturbance with a mean sleep efficiency (SEFF) of 70.9% (SD 10.4%; range 52.27%-92.60%). All 3 CSTs overestimated the total sleep time (TST; bias: >90 min) and SEFF (bias: >13%) and underestimated wake after sleep onset (bias: >50 min). Sleep onset latency was accurately detected by the bedside radar (bias: <6 min) but overestimated by the undermattress devices (bias: >16 min). CSTs did not perform as well as actigraphy in estimating the all-night sleep summary measures. In an epoch-by-epoch concordance analysis, the bedside radar performed better in discriminating sleep versus wake (Matthew correlation coefficient [MCC]: mean 0.63, SD 0.12, 95% CI 0.57-0.69) than the undermattress devices (MCC of WSA: mean 0.41, SD 0.15, 95% CI 0.36-0.46; MCC of Emfit: mean 0.35, SD 0.16, 95% CI 0.26-0.43). The accuracy of identifying rapid eye movement and light sleep was poor across all CSTs, whereas deep sleep (ie, slow wave sleep) was predicted with moderate accuracy (MCC: >0.45) by both Somnofy and WSA. The deep sleep duration estimates of Somnofy correlated (r2=0.60; P<.01) with electroencephalography slow wave activity (0.75-4.5 Hz) derived from PSG, whereas for the undermattress devices, this correlation was not significant (WSA: r2=0.0096, P=.58; Emfit: r2=0.11, P=.21). These CSTs overestimated the TST, and sleep stage prediction was unsatisfactory in this group of older people in whom SEFF was relatively low. Although it was previously shown that CSTs provide useful information on bed occupancy, which may be useful for particular use cases, the performance of these CSTs with respect to the TST and sleep stage estimation requires improvement before they can serve as an alternative to PSG in estimating most sleep variables in older individuals.

The impact of bedroom environment on sleep quality in winter and summer in the Qinghai-Tibetan plateau

The special climatic environment at high-altitude results in common sleep problems for the local inhabitants. Analyzing the relationship between bedroom environment and sleep at high-altitude is one way to improve sleep quality. This study investigated the bedroom environment and sleep quality of plateau dwellers in the Tibetan Plateau region in winter and summer respectively. One hundred and ninety-seven healthy local residents participated in a 1-week bedroom environment and sleep monitoring, resulting in a total of 690 person nights of valid data. The results showed that high-altitude environment caused more wakefulness after sleep onset compared to the NSF recommendation. Sleep of high-altitude residents in summer was associated with more environmental parameters in the bedroom. High Ta, high RH and high CO2 in summer exacerbated the decrease in sleep efficiency and deep sleep duration, with CO2 being the more dominant environmental factor. In winter, the dry environment reduced the length of light sleep for the highlanders, leaving them more sleep deprived when indoor heating was available.

Effect of Emotional Distress on Sleep Physiology in Underserved Pregnant Women [ID: 1381497

INTRODUCTION: Pregnancy is characterized by an altered pattern of emotions and sleep. The aim of this study was to examine the effect of emotional distress on objective sleep parameters in underserved pregnant women during the COVID-19 pandemic. METHODS: Institutional review board approval was obtained for the study. This was a longitudinal observation study in which we administered weekly validated self-reported surveys (Patient Health Questionnaire-2, Generalized Anxiety Disorder-2, COVID-19-related anxiety, and life-related stressors) to consented pregnant women over the course of their second and third trimesters (n=13). The independent variable, subjective emotional distress, was derived from a sum score of these weekly surveys. A wearable device was used to measure objective sleep physiological data, such as the rapid eye movement (REM), deep, and light sleep stages. The dependent variables were obtained from weekly average scores of the sleep data. Multilevel analysis was conducted, controlling for relevant covariates. RESULTS: Adjusting for gestational age, maternal age at enrollment, and prepregnancy body mass index, higher emotional distress was associated with a shorter duration of deep sleep (b=−.65, P&lt;.05) and longer duration of REM sleep (b=.79, P&lt;.01). There was no significant relationship between emotional distress and light sleep. CONCLUSION: Our study appears to be the first to provide preliminary evidence that emotional distress negatively affects sleep in terms of decreased deep sleep and increased REM sleep during pregnancy. Findings suggest that further research is needed to understand the role of sleep in the relationships between emotional distress and adverse maternal and infant health outcomes.

Effects of environmental lighting on students’ sleep, alertness and mood: A field study in a Chinese boarding school

A field study was conducted in two classrooms to explore the effects of standard and high light levels on sleep, alertness and mood of boarding high school students in Suzhou, China. 79 participants took part in a 7-week study in winter. After 3-week baseline assessments under standard lighting, participants were exposed to 3-week high light levels, separated by a 1-week washout. One group experienced this condition in the morning and the other experienced it in the evening. Horizontal illuminance was recorded in real time during the experiment and converted to eye-level vertical illuminance and equivalent melanopic lux. Sleep wristbands and questionnaires were used. Morning or evening high light levels significantly improved acute alertness during the increased light level hours compared with standard lighting, but there was no significant difference in sleep or mood. Additionally, compared to the evening high light levels, morning condition was significantly associated with longer deep sleep duration, easier falling asleep and lower negative mood. This study is the first to directly correlate high light conditions and timing of light exposure with subjective and objective sleep, alertness and mood of Chinese boarding high school students, which can provide references for the application of healthy lighting in classrooms.

РОЛЬ СУБЪЕКТИВНЫХ И ОБЪЕКТИВНЫХ КРИТЕРИЕВ В ОЦЕНКЕ СОСТОЯНИЯ БОЛЬНЫХ БРОНХООБСТРУКТИВНЫМИ ЗАБОЛЕВАНИЯМИ В УСЛОВИЯХ УДАЛЕННОГО МОНИТОРИНГА

Introduction. Wearable or home electronic devices with the function of transmitting information at a distance are used for the purpose of remote dynamic monitoring of the condition of patients. Aim. To determine the effectiveness of the use of "new" criteria for assessing the health status of patients with broncho-obstructive diseases in order to monitor remotely. Material and methods. 28 patients with broncho-obstructive diseases who were admitted for inpatient treatment were examined. Most of them had comorbidities, mainly cardiovascular pathology. A general clinical examination and special research methods were performed: an interactive survey using the respiratory module of the Electronic Polyclinic program, remote monitoring of vital signs using a smart watch and a mobile application for recording and transmitting information, a 6-minute walk test with simultaneous recording of vital signs with using a smart watch, a questionnaire and a scale for assessing the usability of the System usability scale system. The analysis of the results was performed by using the Statistica 13.0 software package. Results and discussion. Interactive survey corresponded to the severity of dyspnea according to the mMRC and Borg scales. The 6-minute walk test showed a significant limitation of physical activity and an increase in heart rate. The deep sleep phase has been limited. The CRP index averaged 7.78±8.48 µg/l. More than 85% of patients expressed their willingness to continue observation. The results of the correlation analysis demonstrated a direct relationship with the patient's physical activity assessment and the results of the 6-minute walk test, and an inverse relationship with the 6-minute walk test result and the patients' age, severity of respiratory failure and CRP concentration. The duration of deep sleep is inversely correlated with the SpO2 value. Our studies made it possible to compare the obtained data with the results of traditional methods of examining a patient, to confirm the position that the physical activity of a patient with broncho-obstructive disease is connected with indicators of the function of external respiration, and also that the total duration of sleep of COPD patients mainly consists of light sleep with a decrease in the duration of deep sleep. An inverse relationship was found with the duration of deep sleep and the concentration of CRP and the value of SpO2. The described monitoring system allows you to timely adjust the treatment regimen, reduce the number of hospitalizations, the risk of exacerbation or death.Conclusion. Additional instrumental control of vital parameters increases the efficiency of the system of long-term remote monitoring of patients with broncho-obstructive diseases. the indicators represent the severity of the symptoms of the disease and the degree of violations of the indicators of the function of external respiration.

Rosmarinic Acid - A Potential Therapeutic Agent for Sleep Disorders

Rosmarinic acid (RA) is a naturally occurring polyphenolic compound found in numerous plants, such as rosemary, salvia, lemon balm, mint, and oregano. It has various pharmacological effects, including antioxidant, anti-inflammatory, anti-aging, antiviral, antibacterial, antidepressant, and sleep-inducing properties. Rosmarinic acid is used in the food industry as a natural preservative and flavour enhancer, in addition to its potential health benefits. The oral bioavailability of RA ranges between 0.91 and 1.61 percent. After oral administration, rosmarinic acid is rapidly absorbed, with peak plasma concentrations occurring within 1-2 hours. The half-life reported for RA is relatively short ranging from 0.75 to 1 hour. Phase II enzymes, such as glucuronidation and sulfation, predominantly metabolise RA in the liver following absorption. These metabolic pathways lead to the formation of numerous conjugated metabolites, which are excreted in the urine and faeces. The bioavailability of RA can vary based on its source, formulation, as well as individual differences in metabolism and other factors. Several studies suggest that RA may have a positive impact on sleep quality, as RA administration has been shown to improve sleep quality, decrease sleep latency, and increase the duration of deep sleep via its effect on the GABAergic system. Moreover, RA has also been shown to have anti-anxiety and calming effects, which may contribute to its sleep-inducing properties. Additional research is necessary to fully comprehend the effects of RA on sleep, including its optimal dose, duration of use, and potential side effects.

IoT-Enabled Intelligent Dynamic Risk Assessment of Acute Mountain Sickness: The Role of Event-Triggered Signal Processing

The rapid developments in Internet of Medical Things open up new avenues for personalized healthcare. Continuously monitored physiological data can be collected by wearable devices and are transmitted to a remote server for real-time monitoring and diagnosis. This article concerns a risk assessment problem of acute mountain sickness (AMS) with data transmitted according to an event-triggered transmission schedule. An event-triggered signal processing approach is introduced to reconstruct the untransmitted information, based on which, a dynamic SpO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{\bf 2}$</tex-math></inline-formula> index (DSI) is further proposed for AMS risk evaluation. The performance of the proposed approach is analyzed through physiological data collected in a proof-of-the-concept study ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> =12). Statistical significant correlation of the DSI with AMS ground truth including Lake Louise score, deep sleep duration, deep sleep ratio, and mean SpO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{\bf 2}$</tex-math></inline-formula> during sleep is observed. More importantly, it is observed that the proposed event-triggered signal processing procedure can dramatically reduce the data transmission rate while maintaining the performance of the DSI assessment, through comparison of the DSI obtained using the proposed event-triggered approach with those obtained based on event-triggered raw data and continuously transmitted time-triggered data. The obtained results indicate the feasibility of adopting event-triggered data scheduling and signal processing to achieve AMS risk evaluation using data from wearable devices with limited communication/battery resources.

Unveiling Interpretable Key Performance Indicators in Hypoxic Response: A System Identification Approach

Advances in wireless networks and wearable electronic devices have enabled the monitoring of massive physiological data for disease diagnosis. In this article, we aim to explore the hypoxic response dynamics through the use of system identification based on physiological data monitored by wearable devices. A third-order autoregressive moving average with exogenous inputs model is developed to describe the dominant system dynamics, based on which an interpretable index called “sum of distance” (SoD) is proposed from a systems and control perspective for AMS risk evaluation. The effectiveness of SoD is evaluated on the basis of physiological data from a proof-of-the-concept study. Statistically, significant relationships of DSI with ground truth AMS metrics (including, Lake Louise score, deep sleep duration, and deep sleep ratio) are observed. To accelerate the evaluation algorithm design, a simulator is designed. A model parameter selection method based on the three-sigma rule is proposed to generate an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in silico</i> population, and a total disturbance sequence is determined for disturbance simulation. The created data has the same trend as the real measurements. The proposed method and experimental results indicate the feasibility of improving the AMS risk evaluation performance by understanding and learning the hypoxic response mechanism.

Experimental study of the negative effects of raised bedroom temperature and reduced ventilation on the sleep quality of elderly subjects.

This study investigated the effects of air temperature and ventilation on the sleep quality of elderly subjects and elucidated the mechanisms involved. Sixteen subjects aged over 65 years old were exposed to four conditions in a 2 × 2 design: air temperatures of 27°C and 30°C (with a ceiling fan in operation at 30°C) and two ventilation conditions (with and without mechanical ventilation) in experimental bedrooms. Their electroencephalogram, electrooculogram, chin electromyogram, electrocardiogram, respiration, oxygen saturation, and wrist skin temperature were measured continuously during sleep. Saliva samples were collected, and blood pressure was measured both before and after sleep. The results showed that at the temperature of 30°C, the total sleep time, sleep efficiency, and duration of REM sleep of the elderly decreased by 26.3min, 5.5%, and 5.3min, respectively, and time awake increased by 27.0min, in comparison with 27°C, indicating that the sleep quality of the elderly is very vulnerable to heat exposure. Even a small heat load led to an overactive sympathetic nervous system and increased wrist skin temperature, which reduced sleep quality. Improving the ventilation increased the duration of deep sleep and REM sleep by 10.3min and 3.7min, respectively. Higher pollutant concentrations affected the respiration and autonomous nervous systems to reduce sleep quality. The benefits of improved thermal environment and ventilation on sleep quality were found to be additive. Good ventilation and the avoidance of raised temperatures in the bedroom are thus both important for the sleep quality of the elderly.

Presleep Heart-Rate Variability Biofeedback Improves Mood and Sleep Quality in Chinese Winter Olympic Bobsleigh Athletes.

To evaluate the effectiveness of heart-rate variability (HRV) biofeedback in improving autonomic function, mood, and sleep in elite bobsleigh athletes. Eight Chinese Winter Olympic bobsleigh athletes (age: 24 [2]y, body mass: 89 [15]kg, and height: 184 [5]cm) completed a randomized crossover study with and without HRV biofeedback before a single night's sleep. HRV biofeedback was provided 35minutes prior to bedtime in the experimental condition. The assessment of HRV took place 45 and 10minutes before bedtime. The Profile of Mood States questionnaire was completed 50 and 15minutes prior to bedtime. Sleep duration and quality were measured through an air-mattress sleep-monitoring system. Sleep efficiency (P = .020; F = 7.831; CI, 0.008 to 0.072) and the percentage of deep sleep duration increased (P = .013; F = 10.875; CI, 0.006 to 0.035), while the percentage of light sleep decreased (P = .034; F = 6.893; CI, -0.038 to -0.002). Presleep HRV biofeedback increased parasympathetic and decreased sympathetic activity. Mood states of anger (P = .006, F = 7.573), panic (P = .031, F = 4.288), tension (P = .011, F = 6.284), depression (P = .010, F = 6.016), fatigue (P = .000, F = 16.901), and total mood disturbance (P = .001, F = 11.225) were reduced before sleep. Presleep HRV biofeedback improved some measures of autonomic function, mood, and sleep quality in Chinese Olympic bobsleigh athletes. Presleep HRV biofeedback provides a practical strategy that may help reduce sleep disturbances during periods of training and competition.

Effect of 4-day Online Breath Meditation Workshop on Ballistocardiography-based Sleep and Cardiac Health Assessments among Medical Professionals of a Tertiary Care Hospital in North India during COVID-19.

Medical professionals (MPs) are facing stress, sleep deprivation, and burnout due to pandemic-related high patient inflow and consistent work shifts. Yoga and meditation are feasible, cost-effective, evidence-based, and well-accepted tools having multifold mental and physical health benefits. In this ongoing open-label single-arm trial, we assessed changes in sleep, heart rate variability (HRV), and vitals before and after a 4-day online breath meditation workshop (OBMW) among 41 MPs at a tertiary care hospital in northern India during COVID-19 pandemic. Outcomes were assessed at baseline and after the 4-day workshop using a ballistocardiography-based contactless health monitoring device. The workshop was conducted online. Two participants were excluded due to a lack of adherence. A highly significant increase was seen in total sleep duration (p = 0.000) and duration of deep sleep (p = 0.001), rapid eye movement (REM) sleep (p = 0.000), and light sleep (p = 0.032). HRV outcomes of the standard deviation of normal-to-normal R-R intervals (SDNN) and root mean square of successive differences between adjacent normal heartbeat (RMSSD) also improved significantly (p = 0.000) while heart rate reduced significantly (p = 0.001). No significant change was observed in breath rate, total time awake, or in the low-frequency by high-frequency (LF/HF) spectrum of HRV. Four days of OBMW improved sleep and HRV among MPs, strengthening the fact that yoga and meditation can help induce psychophysical relaxation and prove to be an effective tool to combat stress and sleep deprivation. As the stakeholders in patient care, that is, MPs are healthy, it will further improve patient care and reduce the chance of medical errors.