[Discrimination of Chin Electromyography in REM Sleep Behavior Disorder Using Deep Learning].

OBJECTIVE: The confirmation of abnormal behavior during video monitoring in polysomnography (PSG) and the frequency of rapid eye movement (REM) sleep without atonia (RWA) during REM sleep based on physiological indicators are essential diagnostic criteria for the diagnosis of REM sleep behavior disorder (RBD). However, no clear criteria have been established for the determination of the tonic and phasic activities of RWA. In this study, we investigated an RWA decision program that simulates visual inspection by clinical laboratory technicians. METHODS: We used the measurement data of 25 men and women (average age±standard deviation: 72.7±1.7 years) who visited the Sleep Treatment Center for PSG inspection due to suspected RBD. The chin electromyography (EMG) during REM sleep was divided into 30 s intervals, and RWA decisions were made on the basis of visual inspection by a clinical laboratory technician. We compared and investigated two machine-learning methods namely support vector machine (SVM) and convolutional neural network (CNN) for RWA decisions. RESULTS: When comparing SVM and CNN, the highest discrimination accuracy for RWA decisions was obtained when using the average rectified value (ARV) processed chin EMG images using CNN as a feature. We also estimated the prevalence of RBD on the basis of the Mahalanobis distance measure using the frequency of occurrence of both tonic and phasic activities calculated from a total of 25 subjects in the patient and healthy groups. Consequently, estimation of RBD prevalence using CNN resulted in misclassification of none of the subjects in the patient group and two subjects in the healthy group. CONCLUSIONS: In this study, we investigated the automatic analysis of PSG results focusing on RBD, which is a parasomnia. As a result, there were no misclassifications of patients in the 25 subjects in the patient or healthy groups based on the estimates of RBD prevalence using CNN. The prevalence estimation based on our proposed automated algorithm is considered effective for the primary screening for RBD.

[Effect of Olfactory Stimulation with Vanilla Odor on Degree of Gastric Myoelectrical Activity].

OBJECTIVES: Olfactory stimulation elicits various physiological responses. However, few reports exist on the changes in gastric motility during olfactory stimulation in humans. In this regard, we carried out electrogastrography (EGG) to non-invasively measure the gastric myoelectrical activity, which regulates gastric motility. Moreover, subjective sensory evaluation was performed to determine which characteristics of vanilla odor at two different concentrations affect the myoelectrical activity. METHODS: The participants consisted of eight healthy young males. EGG and electrocardiography (ECG) recordings were obtained approximately 20 min prior to and during olfactory stimulation. Autonomic nervous system activity was evaluated in terms of heart rate variability (HRV) and mean heart rate (HR) from ECG signals. EGG signals were analyzed by spectral analysis. In addition, the translation error was estimated by the Wayland algorithm. Sensory evaluation was performed using the Visual Analog Scale (VAS). RESULTS: There were no significant differences in HRV and HR values and results of spectral analyses of EGG signals in all sample presentations. The translation error of EGG signals and the rating of perceived odor intensity significantly increased in a concentration-dependent manner. There was a strong positive correlation between translation error and odor intensity. CONCLUSIONS: The correlation found between translation error and odor intensity suggests that the higher the vanilla odor intensity was perceived, the greater the randomness of EGG signals was. Our results suggest that the application of the Wayland algorithm to EGG signals can be used as an objective indicator in odor evaluation.

Minced Skin Grafting for Promoting Wound Healing and Improving Donor-Site Appearance after Split-Thickness Skin Grafting: A Prospective Half-Side Comparative Trial.

BACKGROUND: Minced skin grafting is a procedure that involves mincing of the harvested skin and grafting it back onto the wounds. The authors aimed to investigate whether minced skin grafting reduces the healing time and improves the sequential postoperative appearance of donor sites. METHODS: A single-center, two-treatment, half-side comparative study was performed. The split-thickness skin remaining after grafting was minced until pasty. The small pasty graft mass was uniformly spread on half of the entire donor site. Minced skin grafting was not performed on the other side. The data from 30 patients were used for analysis. RESULTS: The average time to complete healing of the donor sites in the minced skin grafting and control groups was 9.4 ± 2.5 and 12.4 ± 3.6 days, respectively. The difference in the healing time between the two groups was statistically significant (p < 0.001). Three blinded surgeons used a scale to grade photographs according to the degree of conspicuous donor sites in comparison with the normal skin around the donor sites. All observers reported that the differences in donor-site appearance between the minced skin grafting and control groups were statistically significant at postoperative months 1 and 2, and two observers reported that the differences in donor-site appearance were significant at months 4, 6, and 12. The differences in the number of patients with donor-site dyspigmentation between the minced skin grafting and control groups at 12 months were statistically significant (p < 0.05). CONCLUSION: This prospective half-side comparative trial demonstrates that minced skin grafting promotes wound healing and improves donor-site appearance after split-thickness skin grafting. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

[Electromyography Analysis of Rapid Eye Movement Sleep Behavior Disorder].

Polysomnography (PSG), which records physiological phenomena including brain waves, breathing status, and muscle tonus, is useful for the diagnosis of sleep disorders as a gold standard. However, measurement and analysis are complex for several specific sleep disorders, such as rapid eye movement (REM) sleep behavior disorder (RBD). Usually, brain waves during REM sleep indicate an awakening pattern under relaxed conditions of skeletal and antigravity muscles. However, these muscles are activated during REM sleep when patients suffer from RBD. These activated muscle movements during REM, so-called REM without atonia (RWA) recorded by PSG, may be related to a neurodegenerative disease such as Parkinson's disease. Thus, careful analysis of RWA is significant not only physically, but also clinically. Commonly, manual viewing measurement analysis of RWA is time-consuming. Therefore, quantitative studies on RWA are rarely reported. A software program, developed from Microsoft Office Excel®, was used to semiautomatically analyze the RWA ratio extracted from PSG to compare with manual viewing measurement analysis. In addition, a quantitative muscle tonus study was carried out to evaluate the effect of medication on RBD patients. Using this new software program, we were able to analyze RWA on the same cases in approximately 15 min as compared with 60 min in the manual viewing measurement analysis. This software program can not only quantify RWA easily but also identify RWA waves for either phasic or tonic bursts. We consider that this software program will support physicians and scientists in their future research on RBD. We are planning to offer this software program for free to physicians and scientists.

[Study of Equilibrium Control System during a Lowering at Arousal Level].

OBJECTIVES: Contingent negative variation (CNV) is an event-related potential proportional to vigilance degree. A CNV graph shows an inverted U-shape, and this bioreaction disappears after falling below a threshold of vigilance degree. Previous studies have shown that the event-related potential gained with time decreases with sleep deprivation, and a decrease in the vigilance degree has been confirmed using Flicker values (FV) and the Stanford Sleepiness Scale (SSS) score. The minimum integrated value was recorded 24 h after the onset of sleep deprivation. In a present study, we used 36-h sleep deprivation. The FVs, SSS scores, and stabilograms were obtained every 90 min for 52 h, except for the 12 h of sleep. We herein examine whether the biocontrol system is changed by sleep deprivation. RESULTS: The time sequences in FV and SSS score showed that the degree of vigilance markedly decreased 22.5 h after the onset of this experiment, which supported CNV disappearance with sleep deprivation. The sway value with subjects' eyes closed was greatest 22.5 h after the onset of this experiment. Furthermore, there were no significant differences between the sway value during the above-mentioned sleep deprivation and that after 12 h of sleep. We considered that the equilibrium function and vigilance after 36-h sleep deprivation did not recover markedly well with sleep of sufficient duration. That is, the biocontrol process in the subconscious still proceeds after awakening. CONCLUSIONS: In this study, we focused on bioprocessing, especially the equilibrium function, during sleep deprivation and investigated the relationship between the equilibrium function and sleep deprivation. We obtained evidence supporting CNV disappearance after sleep deprivation for 36 h. The equilibrium control system without CNV was compared with that with CNV.

[Effect of Reading a Book on a Tablet Computer on Cerebral Blood Flow in the Prefrontal Cortex].

OBJECTIVES: By measuring cerebral blood flow in the prefrontal cortex, we aimed to determine how reading a book on a tablet computer affects sleep. METHODS: Seven students (7 men age range, 21-32 years) participated in this study. In a controlled illuminance environment, the subjects read a novel in printed form or on a tablet computer from any distance. As the subjects were reading, the cerebral blood flow in their prefrontal cortex was measured by near-infrared spectroscopy. The study protocol was as follows. 1) Subjects mentally counted a sequence of numbers for 30 s as a pretest to standardized thinking and then 2) read the novel for 10 min, using the printed book or tablet computer. In step 2), the use of the book or tablet computer was in a random sequence. Subjects rested between the two tasks. RESULTS: Significantly increased brain activity (increase in regional cerebral blood flow) was observed following reading a novel on a tablet computer compared with that after reading a printed book. Furthermore, the region around Broca's area was more active when reading on a tablet computer than when reading a printed book. CONCLUSIONS: Considering the results of this study and previous studies on physiological characteristics during nonrapid eye movement sleep, we concluded that reading a book on a tablet computer before the onset of sleep leads to the potential inhibition of sound sleep through mechanisms other than the suppression of melatonin secretion.

[Effect of Viewing a Long Stereoscopic Film on Equilibrium Function and Autonomic Nervous System].

OBJECTIVES: Owing to the recent rapid advancements in image processing and three-dimensional (3-D) technologies, stereoscopic images can now be viewed on television as well as in theaters and on gaming consoles among others. However, with these advancements, there have also been reports on motion sickness and asthenopia induced by viewing stereoscopic films. Human equilibrium function deteriorates when viewing stereoscopic films, which may lead to motion sickness; however, the exact cause of such motion sickness remains unknown. Therefore, as part of hygiene research that contributes to society, it is important to consider the safety of viewing virtual 3D contents. METHODS: In this study, we investigated the effects of viewing 2-D/3-D video clips on the human body by stabilometry, electrogastrography (EGG), and subjective assessments. Seven subjects aged 22 to 24 viewed 2-D/3-D video clips for 60 min. RESULTS: A comparison of time series data obtained at rest shows a significant change in the EGG patterns 20 min after the start of viewing the video clips. Furthermore, sway values while viewing the 3-D video clips were considerably higher than those while viewing the 2-D video clips 60 min after the start of viewing. CONCLUSIONS: These findings show that the autonomic nervous system is affected first by long-term viewing of stereoscopic films, and the equilibrium function deteriorates gradually over the course of the exposure.