Implementation of Distracted Estimation System based on Sensor Fusion through Correlation Analysis with Concentration.

Sitting for an extended time may cause a serious chronic disease such as a musculoskeletal disorder, or a cardiovascular disease, diabetes, or obesity. Because a consistently improper posture from early childhood to adolescence can have a number of undesirable effects on the formation of the musculoskeletal structure, learning to maintain a correct posture should be emphasized. A consistently improper posture can not only cause physical problems, it may also lead to emotional issues such as distractions, an attention deficit, and hyperactivity, and the possibility of a low efficiency and performance on assignments is high when the students have a low concentration.

An Efficient Deep Learning Approach to Pneumonia Classification in Healthcare.

This study proposes a convolutional neural network model trained from scratch to classify and detect the presence of pneumonia from a collection of chest X-ray image samples. Unlike other methods that rely solely on transfer learning approaches or traditional handcrafted techniques to achieve a remarkable classification performance, we constructed a convolutional neural network model from scratch to extract features from a given chest X-ray image and classify it to determine if a person is infected with pneumonia. This model could help mitigate the reliability and interpretability challenges often faced when dealing with medical imagery.

Human Heart Rhythms Synchronize While Co-sleeping.

Human physiological systems have a major role in maintenance of internal stability. Previous studies have found that these systems are regulated by various types of interactions associated with physiological homeostasis. However, whether there is any interaction between these systems in different individuals is not well-understood.

Decreased regional brain activity in response to sleep-related sounds after cognitive behavioral therapy for psychophysiological insomnia.

Aim: Patients with psychophysiological insomnia (PI) experience hyperarousal, especially as a reaction to sound stimuli. In the current study, we explored brain activity changes in response to sleep-related sounds (SS) in patients with insomnia after cognitive behavioral therapy for insomnia (CBT-I).

Methods: In 14 drug-free PI patients, regional brain activity in response to SS, and to white noise sound (NS) as neutral stimuli, was investigated before and after individual CBT-I using functional magnetic resonance imaging.

Sleep-Dependent Directional Coupling of Cardiorespiratory System in Patients With Obstructive Sleep Apnea.

Objective: Cardiorespiratory interactions have been widely investigated in different physiological states and conditions. Various types of coupling characteristics have been observed in the cardiorespiratory system; however, it is difficult to identify and quantify details of their interaction. In this study, we investigate directional coupling of the cardiorespiratory system in different physiological states (sleep stages) and conditions, i.

Wakefulness evaluation during sleep for healthy subjects and OSA patients using a patch-type device.

Objectives: Obstructive sleep apnea (OSA) is a major sleep disorder that causes insufficient sleep, which is linked with daytime fatigue and accidents. Long-term sleep monitoring can provide meaningful information for patients with OSA to prevent and manage their symptoms. Even though various methods have been proposed to objectively measure sleep in ambulatory environments, less reliable information was provided in comparison with standard polysomnography (PSG).

Heart rate variability in patients with major depressive disorder and healthy controls during non-REM sleep and REM sleep.

The objectives of this study are to investigate heart rate variability (HRV) in major depressive disorder patients (MDD) and healthy controls during different sleep stages, and to examine the association of HRV during sleep and depression severity. Polysomnography was recorded from 15 depressive patients with a higher beck depression inventory index (BDI > 25, H-BDI-D), 15 depressive patients with a lower BDI index (BDI ≤ 25, L-BDI-D) and 15 healthy controls. HRV was calculated during the first three rapid eye movements (REM) periods and non-REM stages (i.

Periodic Limb Movements in Sleep is Associated with Increased Mortality.

Objective: To elucidate the association between periodic limb movements in sleep (PLMS) and mortality.

Methods: Nocturnal polysomnographic recordings of 1,344 subjects obtained from 1995 to 2008 were reviewed. The subjects were divided into four groups based on PLMS and insomnia: reference group (PLMS≤5), insomnia group (PLMS≤5 with insomnia symptoms), 515 group.

Differential Effects of Obesity on Obstructive Sleep Apnea Syndrome according to Age.

Objective: To evaluate the effect of obesity on obstructive sleep apnea syndrome (OSAS) by age in relation to anthropometric measurements.

Methods: The medical records of 1,110 participants diagnosed with OSAS were analyzed according to age. All participants underwent nocturnal polysomnography and had their body mass index, waist circumference, neck circumference (NC), and waist-to-hip ratio measured.

Exploration of changes in the brain response to sleep-related pictures after cognitive-behavioral therapy for psychophysiological insomnia.

Psychophysiological insomnia (PI) includes arousal to sleep-related stimuli (SS), which can be treated by cognitive behavioral therapy for insomnia (CBT-I). The present study was an exploratory, prospective intervention study that aimed to explore brain response to visual SS in PI before and after CBT-I. Blood oxygen level dependent (BOLD) signal differences in response to SS and neutral stimuli (NS) were compared between 14 drug-free PI patients and 18 good sleepers (GS) using functional magnetic resonance imaging (fMRI).

Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults.

Objective: The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system.

Methods: We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch.

Depressive symptoms are associated with poor sleep quality rather than apnea-hypopnea index or hypoxia during sleep in patients with obstructive sleep apnea.

Purpose: We examined factors, including the severity of obstructive sleep apnea (OSA), that were associated with depressive symptoms and excessive daytime sleepiness in OSA patients.

Methods: We retrospectively reviewed data of 1203 subjects (861 men, mean age 48.2 years) who completed self-reported questionnaires and underwent polysomnography between September 2005 and May 2016 at the Center for Sleep and Chronobiology at Seoul National University Hospital.

Real-Time Automatic Apneic Event Detection Using Nocturnal Pulse Oximetry.

Objective: Nocturnal pulse oximetry has been proposed as a simpler alternative to polysomnography in diagnosing sleep apnea. However, existing techniques are limited in terms of inability to provide time information on sleep apnea occurrence. This study aimed to propose a new strategy for near real-time automatic detection of apneic events and reliable estimation of apnea-hypopnea index using nocturnal pulse oximetry.

Slow-Wave Sleep Estimation for Healthy Subjects and OSA Patients Using R-R Intervals.

We developed an automatic slow-wave sleep (SWS) detection algorithm that can be applied to groups of healthy subjects and patients with obstructive sleep apnea (OSA). This algorithm detected SWS based on autonomic activations derived from the heart rate variations of a single sensor. An autonomic stability, which is an SWS characteristic, was evaluated and quantified using R-R intervals from an electrocardiogram (ECG).

Preliminary Study on Quantitative Sleep EEG Characteristics in Patients with Schizophrenia.

We used quantitative electroencephalography (EEG) spectral analysis to compare activity in the bilateral frontal, central, and occipital areas in nine patients with schizophrenia and ten healthy control subjects during standard nocturnal polysomnography. Patients with schizophrenia had longer sleep latency than controls. In N2 sleep, the patients had significantly lower 0.

REM sleep estimation based on autonomic dynamics using R-R intervals.

Objective: We developed an automatic algorithm to determine rapid eye movement (REM) sleep on the basis of the autonomic activities reflected in heart rate variations.

Approach: The heart rate variability (HRV) parameters were calculated using the R-R intervals from an electrocardiogram (ECG). A major autonomic variation associated with the sleep cycle was extracted from a combination of the obtained parameters.

Apnea-hypopnea index prediction through an assessment of autonomic influence on heart rate in wakefulness.

With the high prevalence of obstructive sleep apnea, the issue of developing a practical tool for obstructive sleep apnea screening has been raised. Conventional obstructive sleep apnea screening tools are limited in their ability to help clinicians make rational decisions due to their inability to predict the apnea-hypopnea index. Our study aimed to develop a new prediction model that can provide a reliable apnea-hypopnea index value during wakefulness.

New predictors of sleep efficiency.

Sleep efficiency is a commonly and widely used measure to objectively evaluate sleep quality. Monitoring sleep efficiency can provide significant information about health conditions. As an attempt to facilitate less cumbersome monitoring of sleep efficiency, our study aimed to suggest new predictors of sleep efficiency that enable reliable and unconstrained estimation of sleep efficiency during awake resting period.

Increased Mortality in Relation to Insomnia and Obstructive Sleep Apnea in Korean Patients Studied with Nocturnal Polysomnography.

Study Objectives: To elucidate the links between the two most prevalent sleep disorders, insomnia and obstructive sleep apnea (OSA), and mortality.

Methods: We studied 4,225 subjects who were referred to the Center for Sleep and Chronobiology, Seoul National University Hospital, from January 1994 to December 2008. We divided the subjects into five groups: mild OSA (5 ≤ AHI < 15), moderate OSA (15 ≤ AHI < 30), severe OSA (AHI ≥ 30), insomnia, and a no-sleep-disorder group consisting of subjects without sleep disorders.

Oxygen Desaturation Index Estimation through Unconstrained Cardiac Sympathetic Activity Assessment Using Three Ballistocardiographic Systems.

Background: Nocturnal hypoxemia, characterized by abnormally low oxygen saturation levels in arterial blood during sleep, is a significant feature of various pathological conditions. The oxygen desaturation index, commonly used to evaluate the nocturnal hypoxemia severity, is acquired using nocturnal pulse oximetry that requires the overnight wear of a pulse oximeter probe.

Objectives: This study aimed to suggest a method for the unconstrained estimation of the oxygen desaturation index.

Apnea-Hypopnea Index Prediction Using Electrocardiogram Acquired During the Sleep-Onset Period.

The most widely used methods for predicting obstructive sleep apnea are based on clinical or anatomico-functional features. To improve exactitude in obstructive sleep apnea screening, this study aimed to devise a new predictor of apnea-hypopnea index. We hypothesized that less irregular respiration cycles would be observed in the patients with more severe obstructive sleep apnea during the sleep-onset period.

Depressed REM Sleep Behavior Disorder Patients Are Less Likely to Recall Enacted Dreams than Non-Depressed Ones.

Objective: REM sleep behavior disorder (RBD) is associated with psychiatric symptoms, such as anxiety and alexithymia. However, only a few studies on the relationship between depression and RBD have been published. In this study, we investigated the occurrence of depression and associated factors in patients with RBD.

Sleep EEG Characteristics in Young and Elderly Patients with Obstructive Sleep Apnea Syndrome.

Objective: In the present study, it was hypothesized that the sleep electroencephalogram (EEG) characteristics of young (<30 yrs) and elderly (>55 yrs) OSAS patients would differ.

Methods: We analyzed 76 sleep EEG recordings from OSAS patients (young group: n=40, mean age: 24.3±4.

Apnea-hypopnea index estimation using quantitative analysis of sleep macrostructure.

Obstructive sleep apnea, characterized by recurrent cessation or substantial reduction in breathing during sleep, is a prevalent and serious medical condition. Although a significant relationship between obstructive sleep apnea and sleep macrostructure has been revealed in several studies, useful applications of this relationship have been limited. The aim of this study was to suggest a novel approach using quantitative analysis of sleep macrostructure to estimate the apnea-hypopnea index, which is commonly used to assess obstructive sleep apnea.

Estimation of sleep posture using a patch-type accelerometer based device.

In this study, we developed a sleep posture estimation algorithm using 3-axis accelerometer signals measured from a patch-type sensor. Firstly, we inspected the characteristics of accelerometer signals for different sleep postures. Based on the results, we established decision rules to estimate 5 postures containing supine, left, right lateral, prone postures, and non-sleep postures such as sitting and standing.