Calibration-Free Driver Drowsiness Classification based on Manifold-Level Augmentation

Drowsiness reduces concentration and increases response time, which causes fatal road accidents. Monitoring drivers' drowsiness levels by electroencephalogram (EEG) and taking action may prevent road accidents. EEG signals effectively monitor the driver's mental state as they can monitor brain dynamics. However, calibration is required in advance because EEG signals vary between and within subjects. Because of the inconvenience, calibration has reduced the accessibility of the brain-computer interface (BCI). Developing a generalized classification model is similar to domain generalization, which overcomes the domain shift problem. Especially data augmentation is frequently used. This paper proposes a calibration-free framework for driver drowsiness state classification using manifold-level augmentation. This framework increases the diversity of source domains by utilizing features. We experimented with various augmentation methods to improve the generalization performance. Based on the results of the experiments, we found that deeper models with smaller kernel sizes improved generalizability. In addition, applying an augmentation at the manifold-level resulted in an outstanding improvement. The framework demonstrated the capability for calibration-free BCI.Comment: Submitted to 2023 11th IEEE International Winter Conference on Brain-Computer Interfac

Outcome Analysis of Cranial Molding Therapy in Nonsynostotic Plagiocephaly

BackgroundIt is known that nonsynostotic plagiocephaly does not spontaneously improve, and the craniofacial deformities that result from it. This study was conducted to analyze the effectiveness of helmet therapy for the nonsynostotic plagiocephaly patient, and to suggest a new treatment strategy based on this analysis.MethodsA total of 108 pediatric patients who had undergone helmet therapy after being diagnosed with nonsynostotic plagiocephaly were included in this study. The patients were classified according to the initiation age of the helmet therapy, severity, and helmet wearing time. The treatment effect was compared using cranial vault asymmetry (CVA) and the cranial vault asymmetry index (CVAI), which were obtained from diagonal measurements before and after therapy.ResultsThe discrepancy of CVA and CVAI of all the patients significantly decreased after helmet therapy. According to the initiation time of helmet therapy, the treatment effect was best at 5 months old or less. The helmet wearing time per day was proportional to the treatment effect up to 20 hours. In addition, the rate of the successful treatment (final CVA ≤5 mm) significantly decreased when the initiation age was 9.1 months or older and the treatment period was less than 7.83 months.ConclusionsThis study showed the effectiveness of the helmet therapy for nonsynostotic plagiocephaly patients. Based on analysis of this study, helmet therapy should be started at the age of 9 months or younger for 7.83 months or more, and the helmet wearing time should be more than 20 hours a day

Comparison of total body irradiation-based or non-total body irradiation-based conditioning regimens for allogeneic stem cell transplantation in pediatric leukemia patients

Purpose : This study aims to compare the outcome of total body irradiation (TBI)- or non-TBI-containing conditioning regimens for leukemia in children. Methods : We retrospectively evaluated 77 children conditioned with TBI (n=40) or non-TBI (n=37) regimens, transplanted at Chonnam National University Hospital between January 1996 and December 2007. The type of transplantation, disease status at the time of transplant, conditioning regimen, engraftment kinetics, development of graft-versus-host disease (GVHD), complications, cause of deaths, overall survival (OS), and event-free survival (EFS) were compared between the 2 groups. Results : Among 34 patients with acute lymphoblastic leukemia (ALL), 28 (82.4%) were in the TBI group, while 72.7% (24/33) of patients with myeloid leukemia were in the non-TBI group. Although the 5-year EFS of the 2 groups was similar for all patients (62% vs 63%), the TBI group showed a better 5-year EFS than the non-TBI group when only ALL patients were analyzed (65% vs 17%&#59; P =0.005). In acute myelogenous leukemia patients, the non-TBI group had better survival tendency (73% vs 38%&#59; P=0.089). The incidence of GVHD, engraftment, survival, cause of death, and late complications was not different between the 2 groups. Conclusion : The TBI and non-TBI groups showed comparable results, but the TBI group showed a significantly higher 5-year EFS than the non-TBI group in ALL patients. Further prospective, randomized controlled studies involving larger number of patients are needed to assess the late-onset complications and to compare the socioeconomic quality of life

Graves disease following rabbit antithymocyte globulin treatment of severe aplastic anemia in a Korean child

Antithymocyte globulin (ATG) is used as an immunosuppressive treatment (IST) to deplete clonal suppressor T cells in patients with severe aplastic anemia (SAA). The depletion of suppressor T cells by ATG may affect the activation of B cells, which results in an increased risk for autoimmune conditions. A 12-year-old boy was diagnosed with idiopathic SAA. As he did not have an human leukocyte antigen-matched sibling, he was treated with rabbit ATG (3.5 mg/kg/day for 5 days) and cyclosporine. Five months later, he became transfusion independent. However, 23 months after IST, he complained of mild hand tremors, sweating, weight loss, palpitations, and goiter. Results of thyroid function tests revealed hyperthyroidism (free thyroxine, 3.42 ng/dL; thyroid stimulating hormone [TSH], <0.01 nIU/mL; triiodothyronine, 3.99 ng/mL). Results of tests for autoantibodies were positive for the antimicrosome antibody and TSH-binding inhibitory immunoglobulin, but negative for the antithyroglobulin antibody and antinuclear antibody. He was treated with methimazole, and his symptoms improved. The patient has been disease free for 39 months after IST and 9 months after methimazole treatment. This case report suggests that although rare, rabbit ATG may have implications in the pathogenesis of autoimmune hyperthyroidism. Our findings suggest that thyroid function tests should be incorporated in the routine follow-up of SAA patients treated with ATG

C-Band GaN Dual-Feedback Low-Noise Amplifier MMIC with High-Input Power Robustness

In this paper, using the 0.2 μm ETRI GaN HEMT process, we developed a C-band GaN dual-feedback low-noise amplifier MMIC for an RF receiver module that requires high-input power robustness. By applying a feedback microstrip line at the source of the transistor and series resistor-capacitor (RC) feedback between the gate and the drain of the transistor, we obtained stable amplifier operation and a compromised impedance trace for both input impedance matching and noise matching while suppressing performance degradation of the maximum available gain and minimum noise figure. The developed low-noise amplifier MMIC, which implements simple matching circuits by using biasing elements as matching elements, had a linear gain of more than 21.4 dB and a noise figure of less than 1.91 dB in the wide bandwidth of 4.3–7.4 GHz. Under the single-tone power test, the low-noise amplifier MMIC had an output P1dB of 14.3–20.1 dBm, and the two-tone intermodulation distortion measurement exhibited an input third-order intercept point (IIP3) of 2.2–5.6 dBm in the same frequency range as the above

Collagen Immobilization on Ultra-thin Nanofiber Membrane to Promote In Vitro Endothelial Monolayer Formation

The endothelialization on the poly (epsilon-caprolactone) nanofiber has been limited due to its low hydrophilicity. The aim of this study was to immobilize collagen on an ultra-thin poly (epsilon-caprolactone) nanofiber membrane without altering the nanofiber structure and maintaining the endothelial cell homeostasis on it. We immobilized collagen on the poly (epsilon-caprolactone) nanofiber using hydrolysis by NaOH treatment and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/sulfo-N-hydroxysulfosuccinimide reaction as a cost-effective and stable approach. NaOH was first applied to render the poly (epsilon-caprolactone) nanofiber hydrophilic. Subsequently, collagen was immobilized on the surface of the poly (epsilon-caprolactone) nanofibers using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/sulfo-N-hydroxysulfosuccinimide. Scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and fluorescence microscopy were used to verify stable collagen immobilization on the surface of the poly (epsilon-caprolactone) nanofibers and the maintenance of the original structure of poly (epsilon-caprolactone) nanofibers. Furthermore, human endothelial cells were cultured on the collagen-immobilized poly (epsilon-caprolactone) nanofiber membrane and expressed tight junction proteins with the increase in transendothelial electrical resistance, which demonstrated the maintenance of the endothelial cell homeostasis on the collagen-immobilized-poly (epsilon-caprolactone) nanofiber membrane. Thus, we expected that this process would be promising for maintaining cell homeostasis on the ultra-thin poly (epsilon-caprolactone) nanofiber scaffolds.11Ysciescopu