Analysis of taVNS effects on autonomic and central nervous systems in healthy young adults based on HRV, EEG parameters.

Objective.Transcutaneous auricular vagus nerve stimulation (taVNS), a non-invasive method of stimulating the vagus nerve, simultaneously affects the autonomic nervous system (ANS) and central nervous system (CNS) through efferent and afferent pathways. The purpose of this study is to analyze the effect of taVNS on the ANS and CNS through heart rate variability (HRV) and electroencephalography (EEG) parameters of identified responders.Approach.Two sets of data were collected from each of 10 healthy adult male subjects in their 20 s, and five HRV parameters from the time domain (RMSSD, pNN50, pNN30, pNN20, ppNNx) and two EEG parameters (power of alpha band, power of delta band) were extracted.Main results.Based on pNN50, responders to taVNS were identified; among them, pNN50 (p= 0.0041) and ppNNx (p= 0.0037) showed significant differences before and after taVNS. At the same time, for alpha power and delta power of EEG, significant difference (p< 0.05) was observed in most channels after taVNS compared to before stimulation.Significance.This study demonstrated the validity of identifying responders using pNN50 and the influence of taVNS on both the ANS and CNS. We conclude that taVNS can be used to treat a variety of diseases and as a tool to help control the ANS and CNS.

Multiscale distribution entropy analysis of short epileptic EEG signals.

This paper proposes an information-theoretic measure for discriminating epileptic patterns in short-term electroencephalogram (EEG) recordings. Considering nonlinearity and nonstationarity in EEG signals, quantifying complexity has been preferred. To decipher abnormal epileptic EEGs, i.e., ictal and interictal EEGs, via short-term EEG recordings, a distribution entropy (DE) is used, motivated by its robustness on the signal length. In addition, to reflect the dynamic complexity inherent in EEGs, a multiscale entropy analysis is incorporated. Here, two multiscale distribution entropy (MDE) methods using the coarse-graining and moving-average procedures are presented. Using two popular epileptic EEG datasets, i.e., the Bonn and the Bern-Barcelona datasets, the performance of the proposed MDEs is verified. Experimental results show that the proposed MDEs are robust to the length of EEGs, thus reflecting complexity over multiple time scales. In addition, the proposed MDEs are consistent irrespective of the selection of short-term EEGs from the entire EEG recording. By evaluating the Man-Whitney U test and classification performance, the proposed MDEs can better discriminate epileptic EEGs than the existing methods. Moreover, the proposed MDE with the moving-average procedure performs marginally better than one with the coarse-graining. The experimental results suggest that the proposed MDEs are applicable to practical seizure detection applications.

Effects of Game-Related Tasks for the Diagnosis and Classification of Gaming Disorder.

Gaming disorder (GD) is an addictive behavior characterized by an insatiable need to play video games and shares similar symptoms with the failure of self-control due to a decline in cognitive function. Current GD diagnostic and screening tools rely on questionnaires and behavioral observations related to cognitive functions to assess an individual's capacity to maintain self-control in everyday life. However, current GD screening approaches rely on subjective symptoms, and a reliable diagnosis requires long-term clinical follow-up. Recent studies have measured biosignals along with cognitive functional tasks to provide objectivity to GD diagnosis and to acquire immediate results. However, people with GD are hypersensitive to game-related cues, so their responses may vary depending on the type of stimuli, and the difference in response to stimuli might manifest as a difference in the degree of change in the biosignal. Therefore, it is critical to choose the correct stimulus type when performing GD diagnostic tasks. In this study, we investigated the task dependence of cognitive decline in GD by comparing two cognitive functional tasks: a continuous performance task (CPT) and video game play. For this study, 69 young male adults were classified into either the gaming disorder group (GD, n = 39) or a healthy control group (HC, n = 30). CPT score, EEG signal (theta, alpha, and beta), and HRV-HF power were assessed. We observed differences in the left frontal region (LF) of the brain between the GD and HC groups during online video game play. The GD group also showed a significant difference in HF power of HRV between CPT and online video gaming. Furthermore, LF and HRV-HF significantly correlated with Young's Internet Addiction Test (Y-IAT) score, which is positively associated with impulsivity score. The amount of change in theta band activity in LF and HRV-HF-both biomarkers for changes in cognitive function-during online video game play suggests that people with GD express task-dependent cognitive decline compared with HC. Our results demonstrate the feasibility of quantifying individual self-regulation ability for gaming and underscore its importance for GD classification.

Numerical study on the hydrodynamic performance and internal flow of an axial-flow pump with various inlet flow angles.

In this study, numerical simulation was employed to predict the performance and internal flow characteristics of the inlet of an axial-flow pump by assigning an absolute flow angle to the inlet guide vane (IGV) trailing-edge flow. Further, the finite volume method based on the three-dimensional Reynolds-averaged Navier-Stokes equations was employed to discretize the governing equations. The shear stress transport model was used as the turbulence model, and an appropriate number of nodes were selected for the hexahedral grid system through a grid-dependency test. The performance curve and changes in the internal flow field were investigated based on the variation in the flow angle at the inlet of the axial-flow pump. These results can be used to establish an efficient operational plan by adjusting the IGV angle of IGV when installing a variable IGV for an axial-flow pump.

Multiscale Cumulative Residual Dispersion Entropy with Applications to Cardiovascular Signals.

Heart rate variability (HRV) is used as an index reflecting the adaptability of the autonomic nervous system to external stimuli and can be used to detect various heart diseases. Since HRVs are the time series signal with nonlinear property, entropy has been an attractive analysis method. Among the various entropy methods, dispersion entropy (DE) has been preferred due to its ability to quantify the time series' underlying complexity with low computational cost. However, the order between patterns is not considered in the probability distribution of dispersion patterns for computing the DE value. Here, a multiscale cumulative residual dispersion entropy (MCRDE), which employs a cumulative residual entropy and DE estimation in multiple temporal scales, is presented. Thus, a generalized and fast estimation of complexity in temporal structures is inherited in the proposed MCRDE. To verify the performance of the proposed MCRDE, the complexity of inter-beat interval obtained from ECG signals of congestive heart failure (CHF), atrial fibrillation (AF), and the healthy group was compared. The experimental results show that MCRDE is more capable of quantifying physiological conditions than preceding multiscale entropy methods in that MCRDE achieves more statistically significant cases in terms of p-value from the Mann-Whitney test.

HGTree v2.0: a comprehensive database update for horizontal gene transfer (HGT) events detected by the tree-reconciliation method.

HGTree is a database that provides horizontal gene transfer (HGT) event information on 2472 prokaryote genomes using the tree-reconciliation method. HGTree was constructed in 2015, and a large number of prokaryotic genomes have been additionally published since then. To cope with the rapid rise of prokaryotic genome data, we present HGTree v2.0 (http://hgtree2.snu.ac.kr), a newly updated version of our HGT database with much more extensive data, including a total of 20 536 completely sequenced non-redundant prokaryotic genomes, and more reliable HGT information results curated with various steps. As a result, HGTree v2.0 has a set of expanded data results of 6 361 199 putative horizontally transferred genes integrated with additional functional information such as the KEGG pathway, virulence factors and antimicrobial resistance. Furthermore, various visualization tools in the HGTree v2.0 database website provide intuitive biological insights, allowing the users to investigate their genomes of interest.

Numerical investigation on functional limitations of the anti-stall fin for an axial fan: one-factor analyses.

The stall in an axial fan is directly related to detrimental phenomena such as performance degradation, vibration, noise, and flow instability at low flow rates. As a kind of passive control method to handle the stall, two-dimensional plates so-named anti-stall fin (ASF) were suggested by ourselves and were attached inside the casing. In this study, the ASF's effect on the internal flow pattern was visually investigated in the flow passage, and its tendency was discussed with the performance curve. Subsequently, the ASF's functional limitations for various design parameters, which the ASF can derive aerodynamically, were presented as the primary focus of this study. Each one-factor analysis was performed, and the internal flow pattern was observed in parallel at the point where the ASF lost its function. For the radial length, axial length, number of fins, and positive-tangential angle, the ASF almost retained its function up to the limitation to prevent instability but radically lost its function at a certain flow rate. For the axial gap and negative-tangential angle, the ASF gradually lost its function. Mostly, this study was based on numerical analysis, and the performance was validated through experimental tests.

Effects of Task-Based LSVT-BIG Intervention on Hand Function, Activity of Daily Living, Psychological Function, and Quality of Life in Parkinson's Disease: A Randomized Control Trial.

Previous studies have demonstrated that the Lee Silverman Voice Treatment-BIG (LSVT-BIG) program can improve motor functions such as balance and gait in Parkinson's disease (PD) patients. However, no study has investigated the effects of a task-based LSVT-BIG intervention on hand function, psychological function, and quality of life in PD patients. Herein, we investigate the effects of a task-based LSVT-BIG intervention, which reflects the needs of PD patients, on hand function, activity of daily living (ADL), psychological function, and quality of life. A total of 14 PD patients were enrolled and randomly assigned to the experimental or control group. The experimental group performed 30 minutes of conventional occupational therapy and 40 minutes of the task-based LSVT-BIG program. The control group performed 30 minutes of conventional occupational therapy and 40 minutes of relaxation and stretching. Both groups underwent the respective interventions once a day 5 times a week for 4 weeks. As a result of the study, the experimental group showed improvement in hand function in both the dominant and nondominant hand, and the control group showed improvement only in the nondominant hand (p < .05). ADL was significantly improved in both groups, but the experimental group showed a more statistically significant difference than the control group (p < .05). Depression and anxiety were significantly decreased in both the experimental group and the control group, and in particular, in the case of anxiety, there was a more statistically significant difference in the experimental group (p < .05). In the case of the experimental group, there was a significant improvement in quality of life in all items, and in the control group, except for the social function item (p > .05), there was a significant improvement in other items (p < .05). The results of this study suggest that the task-based LSVT-BIG program, which consists of activities desired by the participants, may be an effective intervention to improve hand function, ADL, psychological function, and quality of life in PD patients.

The increased analgesic efficacy of cold therapy after an unsuccessful analgesic experience is associated with inferior parietal lobule activation.

Prior experiences of successful and failed treatments are known to influence the efficacy of a newly applied treatment. However, whether that carry-over effect applies to non-pharmacological treatments is unknown. This study investigated how a failed treatment history with placebo analgesic cream affected the therapeutic outcomes of cold-pack treatment. The neural correlates underlying those effects were also explored using functional magnetic resonance imaging. The effect of the placebo analgesic cream was induced using placebo conditioning with small (44.5 °C to 43.7 °C, negative experience) and large (44.5 °C to 40.0 °C, positive experience) thermal stimuli changes. After the placebo conditioning, brain responses and self-reported evaluations of the effect of subsequent treatment with a cold-pack were contrasted between the two groups. The negative experience group reported less pain and lower anxiety scores in the cold-pack condition than the positive experience group and exhibited significantly greater activation in the right inferior parietal lobule (IPL), which is known to be involved in pain relief. These findings suggest that an unsatisfying experience with an initial pain-relief treatment could increase the expectations for the complementary treatment outcome and improve the analgesic effect of the subsequent treatment. The IPL could be associated with this expectation-induced pain relief process.

Positive Effect of Lactobacillus acidophilus EG004 on Cognitive Ability of Healthy Mice by Fecal Microbiome Analysis Using Full-Length 16S-23S rRNA Metagenome Sequencing.

Evidence for the concept of the "gut-brain axis" (GBA) has risen. Many types of research demonstrated the mechanism of the GBA and the effect of probiotic intake. Although many studies have been reported, most were focused on neurodegenerative disease and, it is still not clear what type of bacterial strains have positive effects. We designed an experiment to discover a strain that positively affects brain function, which can be recognized through changes in cognitive processes using healthy mice. The experimental group consisted of a control group and three probiotic consumption groups, namely, Lactobacillus acidophilus, Lacticaseibacillus paracasei, and Lacticaseibacillus rhamnosus. Three experimental groups fed probiotics showed an improved cognitive ability by cognitive-behavioral tests, and the group fed on L. acidophilus showed the highest score. To provide an understanding of the altered microbial composition effect on the brain, we performed full 16S-23S rRNA sequencing using Nanopore, and operational taxonomic units (OTUs) were identified at species level. In the group fed on L. acidophilus, the intestinal bacterial ratio of Firmicutes and Proteobacteria phyla increased, and the bacterial proportions of 16 species were significantly different from those of the control group. We estimated that the positive results on the cognitive behavioral tests were due to the increased proportion of the L. acidophilus EG004 strain in the subjects' intestines since the strain can produce butyrate and therefore modulate neurotransmitters and neurotrophic factors. We expect that this strain expands the industrial field of L. acidophilus and helps understand the mechanism of the gut-brain axis. IMPORTANCE Recently, the concept of the "gut-brain axis" has risen and suggested that microbes in the GI tract affect the brain by modulating signal molecules. Although many pieces of research were reported in a short period, a signaling mechanism and the effects of a specific bacterial strain are still unclear. Besides, since most of the research was focused on neurodegenerative disease, the study with a healthy animal model is still insufficient. In this study, we show using a healthy animal model that a bacterial strain (Lactobacillus acidophilus EG004) has a positive effect on mouse cognitive ability. We experimentally verified an improved cognitive ability by cognitive behavioral tests. We performed full 16S-23S rRNA sequencing using a Nanopore MinION instrument and provided the gut microbiome composition at the species level. This microbiome composition consisted of candidate microbial groups as a biomarker that shows positive effects on cognitive ability. Therefore, our study suggests a new perspective for probiotic strain use applicable for various industrialization processes.

Influential Factors for Sustainable Intention to Visit a National Park during COVID-19: The Extended Theory of Planned Behavior with Perception of Risk and Coping Behavior.

Despite the danger of the spread of the COVID-19 pandemic, visits to natural tourism destinations such as national parks are continuing, though people are using less congested trails or minimizing personal contact. Given the danger from COVID-19, the purpose of our study was to use an expanded theory of planned behavior to analyze whether tourists intend to continue to visit national parks. Another purpose for our study was to compare an extant research model based on the theory of planned behavior with the extended model we developed. Frequency analysis, confirmatory factor analysis, structural equation modeling, and other statistical techniques, such as correlation analysis, parsimonious fit index, and squared multiple correlations were employed according to the appropriate objectives. Additionally, the number of 351 participants joined the survey. Our study found that perception of risk of COVID-19 negatively affected attitude and perceived behavioral control in both models. Moreover, the perceived behavioral control had a positive effect on coping behavior. Given the analytical results, our study presents not only theoretical implications for understanding the behavior of those who visit national parks, but also practical implications for operation and management of national parks during the COVID-19 pandemic.

Complete Genome Sequence of the Newly Developed Lactobacillus acidophilus Strain With Improved Thermal Adaptability.

Lactobacillus acidophilus (L. acidophilus) is a representative probiotic and is widely used in many industrial products for its beneficial effects on human and animal health. This bacterium is exposed to harsh environments such as high temperatures for manufacturing industrial products, but cell yield under high temperatures is relatively low. To resolve this issue, we developed a new L. acidophilus strain with improved heat resistance while retaining the existing beneficial properties through the adaptive laboratory evolution (ALE) method. The newly developed strain, L. acidophilus EG008, has improved the existing limit of thermal resistance from 65°C to 75°C. Furthermore, we performed whole-genome sequencing and comparative genome analysis of wild-type and EG008 strains to unravel the molecular mechanism of improved heat resistance. Interestingly, only two single-nucleotide polymorphisms (SNPs) were different compared to the L. acidophilus wild-type. We identified that one of these SNPs is a non-synonymous SNP capable of altering the structure of MurD protein through the 435th amino acid change from serine to threonine. We believe that these results will directly contribute to any industrial field where L. acidophilus is applied. In addition, these results make a step forward in understanding the molecular mechanisms of lactic acid bacteria evolution under extreme conditions.

Clinical Efficacy and Safety of Low-Level Laser Therapy in Patients with Perennial Allergic Rhinitis: A Randomized, Double-Blind, Placebo-Controlled Trial.

Allergic rhinitis (AR) is a common disease that interferes with the daily activities and reduces the quality of life. Conventional treatments often do not provide complete resolution of the symptoms, and many new treatment modalities have been tried. This study aimed to evaluate the efficacy and safety of low-level laser therapy (LLLT) for AR in a randomized, double-blind, placebo-controlled trial. Patients diagnosed with AR were randomly allocated to receive LLLT or sham treatment. The primary outcome was a change in the reflective total nasal symptom score (TNSS). The secondary outcome was quality of life scores assessed using the Rhinoconjunctivitis Quality of Life Questionnaire. Incidences of adverse events were also recorded. Among 67 randomized subjects, 41 subjects (22 in LLLT group and 19 in sham treatment group) were included for efficacy analysis. The LLLT group showed a significantly improved TNSS score compared to the sham treatment group for decreasing AR symptom severity (p = 0.011) and improving quality of life regarding nasal symptoms (p = 0.036) at the end of treatment. Throughout the treatment period, no severe adverse events occurred. This clinical trial showed that LLLT is an effective and safe option for the management of AR regarding symptom relief and quality of life improvement.

Enhancing SSVEP-Based Brain-Computer Interface with Two-Step Task-Related Component Analysis.

Among various methods for frequency recognition of the steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) study, a task-related component analysis (TRCA), which extracts discriminative spatial filters for classifying electroencephalogram (EEG) signals, has gathered much interest. The TRCA-based SSVEP method yields lower computational cost and higher classification performance compared to existing SSVEP methods. In spite of its utility, the TRCA-based SSVEP method still suffers from the degradation of the frequency recognition rate in cases where EEG signals with a short length window are used. To address this issue, here, we propose an improved strategy for decoding SSVEPs, which is insensitive to a window length by carrying out two-step TRCA. The proposed method reuses the spatial filters corresponding to target frequencies generated by the TRCA. Followingly, the proposed method accentuates features for target frequencies by correlating individual template and test data. For the evaluation of the performance of the proposed method, we used a benchmark dataset with 35 subjects and confirmed significantly improved performance comparing with other existing SSVEP methods. These results imply the suitability as an efficient frequency recognition strategy for SSVEP-based BCI applications.

Correlation between short-time and whole-night obstruction level tests for patients with obstructive sleep apnea.

Identification of obstructive level is crucial for successful surgical outcomes in patients with obstructive sleep apnea (OSA). Unfortunately, most of the dynamic airway evaluations are performed for a short duration under drug-induced sleep; therefore, it is uncertain whether they represent airway events that occur during a whole night of sleep. This study was aimed to evaluate the correlation between obstructive levels that were identified by a short-time and a whole-night test in patients with OSA. Total 101 patients with OSA underwent drug-induced sleep fluoroscopy (DISF) and pressure manometry (PM). For DISF, the obstructive pattern was classified into one of three groups: soft palate, tongue-based, and a combined obstruction. PM was used to measure the proportion of retroglossal events out of total whole-night obstructive events in each patient. The mean age of the patients was 43.8 years. The obstructive pattern was identified as soft palate in 56 patients, combined in 38 patients, and tongue-based in 7 patients following DISF. Results from PM showed that the mean percentage of retroglossal obstructive events was 31.2 ± 30.7%. The average proportion of retroglossal obstructive events that were identified by PM in patients with soft palate, combined, and tongue-based obstruction was 27.2%, 32.1%, and 59.0%, respectively (p = 0.033). There are limitations of evaluating obstructive events that occur during a whole night with short-time tests. Surgeons should be aware the possibility of disagreement in the obstructive level between short-time and whole-night tests.

Dexamethasone and post-adenotonsillectomy pain in children: Double-blind, randomized controlled trial.

OBJECTIVE: To assess the impact of intraoperative intravenous dexamethasone on the reduction of postoperative morbidity in children undergoing adenotonsillectomy. METHODS: A double blind randomized controlled trial conducted among children undergoing adenotonsillectomy at a tertiary hospital in Korea from November 2018 to June 2019. Children were randomly assigned to receive dexamethasone (0.5 mg/kg, maximum dose 24 mg) or placebo intravenously after induction of anesthesia. The primary endpoint was the reduction of postoperative pain and postoperative nausea and vomiting (PONV); secondary endpoints were adverse effects like postoperative hemorrhage. RESULTS: The study included 105 children, and 67 were male. Their mean age was 6.2 ±â€Š2.1 years. There was no significant difference between the groups in terms of demographic data or the operation time. The pain scores of the dexamethasone group were lower than those of the control group, but no significant difference was found (all P > .05). The average pain visual analog scale (VAS) during the study period (day 0-7) was 3.67 ±â€Š1.59 and 4.40 ±â€Š2.01 in the dexamethasone group and control group, respectively (P-value = .107). When we compared early pain VAS (day 0-2) and late pain VAS (day 5-7), the dexamethasone group showed significantly lower early mean VAS compared to the control group (4.55 ±â€Š1.78 vs 5.40 ±â€Š2.05, P-value = .046). The mean VAS for PONV was significantly lower in the dexamethasone group than in the control group (1.89 ±â€Š2.22 vs 3.00 ±â€Š2.37, P value = .044). CONCLUSION: In children undergoing adenotonsillectomy, dexamethasone decreased the early postoperative pain and PONV without increasing postoperative hemorrhage.

Evaluation of the Esthetic and Functional Outcomes of Extracorporeal Septoplasty for Rhinoplasty in Asian Patients.

OBJECTIVES: In extracorporeal septoplasty (ECS), the entire septal cartilage is harvested, and a neo-L strut is built extracorporeally. Thus, ECS can simultaneously achieve septum straightening and tip projection. This study evaluated the functional and esthetic outcomes of the ECS technique for rhinoplasty in Asian patients. METHODS: We conducted a retrospective review of 64 patients who underwent rhinoplasty using ECS between January 2016 and March 2018. Subjective patient satisfaction was assessed and objective surgical outcomes were evaluated. Improvement in nasal obstruction was rated using a visual analog scale (VAS). Anthropometric changes were compared between preoperative and postoperative facial photographs. Complications and revisions were also analyzed. RESULTS: The participants comprised 64 patients (48 males and 16 females, with a mean age of 29.3 years). The mean operative time was 89.3 minutes. In total, 61 patients were satisfied with the esthetic outcome, and the overall objective rhinoplasty outcome score was 3.45. Preoperative nasal obstruction symptoms (7.9±1.2 on VAS) improved postoperatively (3.1±1.3, P<0.001), and significant improvements were also observed in the nasofrontal angle (152.3° to 148.1°, P<0.001), nasolabial angle (88.8° to 92.0°, P<0.001), and nasal tip projection (0.62 to 0.66, P<0.033). Recurrent deviation of the nasal septum and external nose or tip deprojection did not occur in any patients, and there were no cases of revision during the mean follow-up period of 13.3 months. CONCLUSION: ECS might be an esthetically and functionally satisfactory alternative rhinoplasty technique for Asian patients with a shortage of septal cartilage.

Increased Risk of Psychopathological Abnormalities in Subjects With Unilateral Hearing Loss: A Cross-Sectional Study.

OBJECTIVES: Although unilateral hearing loss (UHL) has been proven to be associated with educational and behavioral problems, few studies have investigated psychopathological abnormalities in this population. The aim of this study was to evaluate the psychopathological influence of UHL among Korean 19-year-old males. METHODS: The authors retrospectively compared the objective personality test profiles of 602 subjects with UHL with those of 23,790 peers with normal hearing. All participants in the current study were 19-year-old males who underwent a physical examination and completed the Korean Military Multiphasic Personality Inventory for conscription at the Military Manpower Administration from February 2015 to December 2016. RESULTS: Significantly higher scores were found on neurosis scales in the UHL group than in the normal-hearing group (50.9± 10.8 vs. 44.9±6.0 for anxiety; 51.0±10.5 vs. 44.9±5.2 for depression; 51.1±10.4 vs. 45.1±6.81 for somatization, all P<0.001). The psychopathy scales were also significantly higher in the UHL group than in the normal-hearing group (49.3±9.4 vs. 46.3±5.7 for schizophrenia; 51.1±11.2 vs. 44.3±5.8 for personality disorders; 51.1±10.5 vs. 45.7±3.7 for paranoia, all P<0.001). CONCLUSION: Nineteen-year-old males with UHL tended to have more abnormal results on personality tests than controls with normal hearing, suggesting that UHL may be related with a higher risk of psychopathology.

Results of Hearing Outcome According to the Alloplastic Ossicular Prosthesis Materials.

The aim of this study is to compare the functional results and extrusion rates according to the type of ossciular alloplastic prosthesis. In this study, a retrospective analysis was performed. Sixty-one patients were involved in partial ossicular replacement (POR) cases and 70 patients were involved in total osscicular replacement (TOR) cases. In POR cases, Plastipore was used in 21 cases, hydroxyapatite in 20 cases, and titanium in 20 cases. In TOR cases, Plastipore was used in 20 cases, hydroxyapatite (HA) in 25 cases and titanium in 25 cases. We reviewed postoperative ABG (less than 20 dB or more than 20 dB) and the extrusion rate for more than 1 year follow-up period. In POR cases, ABG less than 20 dB were 71.4, 80.0, 85.0 % in plastipore, HA, and titanium prosthesis and in TOR cases, ABG less than 20 dB were 25.0, 28.0, 32.0 % in plastipore, HA, and titanium prostheses, respectively. In POR cases, extrusion rates (ER) were 9.5, 5.0, 5.0 % in plastipore, HA, and titanium prosthesis, respectively. In TOR cases, ER were 15.0, 8.0, 4.0 % in plastipore, HA, and titanium prosthesis, respectively. There were no significant differences in hearing gain results among plastipore, HA, and titanium in both POR and TOR cases, but the ER was significantly low in titanium. Clinically relatively better hearing gain and low-rate of extrusion were found in titanium prosthesis and thus this material is recommended in cases of ossicular alloplastic replacement surgery.

Multiscale Distribution Entropy Analysis of Short-Term Heart Rate Variability.

Electrocardiogram (ECG) signal has been commonly used to analyze the complexity of heart rate variability (HRV). For this, various entropy methods have been considerably of interest. The multiscale entropy (MSE) method, which makes use of the sample entropy (SampEn) calculation of coarse-grained time series, has attracted attention for analysis of HRV. However, the SampEn computation may fail to be defined when the length of a time series is not enough long. Recently, distribution entropy (DistEn) with improved stability for a short-term time series has been proposed. Here, we propose a novel multiscale DistEn (MDE) for analysis of the complexity of short-term HRV by utilizing a moving-averaging multiscale process and the DistEn computation of each moving-averaged time series. Thus, it provides an improved stability of entropy evaluation for short-term HRV extracted from ECG. To verify the performance of MDE, we employ the analysis of synthetic signals and confirm the superiority of MDE over MSE. Then, we evaluate the complexity of short-term HRV extracted from ECG signals of congestive heart failure (CHF) patients and healthy subjects. The experimental results exhibit that MDE is capable of quantifying the decreased complexity of HRV with aging and CHF disease with short-term HRV time series.