• Journal of radiological science and technology
• /
• v.42 no.5
• /
• pp.345-350
• /
• 2019

Liver biopsy is the gold standard for diagnosing liver fibrosis, but it is invasive and has a risk for complications. For this reason, recently, study has been actively conducted on non-invasive liver fibrosis evaluation method. But, there is no established standard for the type of diffuse liver disease. Therefore, this study was suggest the usefulness and cut-off values of Fibroscan, FIB-4, APRI and AAR of patients with hepatitis C in Korea. According to the diagnosis, 240 people in hepatitis C are classified into fatty liver, chronic hepatitis, and liver cirrhosis. The statistical analysis was performed by ANOVA to verify difference between groups. The ROC curve was analyzed to determine the usefulness and practical cut-off value. As a result, for all diseases, the AUC value for Fibroscan was 0.8 over and the APRI was 0.7 over. Cut-off value of serum based liver fibrosis markers was increased in order of fatty liver, chronic hepatitis and liver cirrhosis. If Fibroscan and serological liver fibrosis markers are applied to predict liver fibrosis, it is expected that excessive liver biopsy can be reduced.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.1
• /
• pp.203-210
• /
• 2021

Difficulties in treating chronic prostatitis cause physical pain and mental problems not only for the treating doctor, but also for the patient. Accordingly, the device of the present research was developed to help patients suffering from prostate symptoms due to the vibration effect of shock wave energy caused by thermal and mechanical interaction of the external shock wave. The purpose of this study is to provide an effective treatment means for prostatitis and BPH(Benign prostatic hyperplasia) by devising an extracorporeal shockwave therapy device that effectively applies the heat and vibration effects of concentrated energy by MCU and spiral coil module.

• Korean Journal of Optics and Photonics
• /
• v.32 no.3
• /
• pp.114-119
• /
• 2021

A large-area graphene sheet has been successfully grown on a copper-foil substrate by chemical vapor deposition (CVD) for industrial use. To screen out unsatisfactory graphene films as quickly as possible, noninvasive optical characterization in reflection geometry is necessary. Based on the optical conductivity of graphene, developed by the single-electron tight-binding method, we have investigated the optical-reflectance contrast. Depending on the four independent control parameters of layer number, chemical potential, hopping energy, and temperature, the optical-reflectance contrast can change dramatically enough to reveal the quality of the grown graphene sheet.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.29 no.1
• /
• pp.54-61
• /
• 2020

Forced orthodontic eruption(FOE) is a non-surgical treatment approach that allows augmenting both soft- and hard-tissue profiles of potential implant sites, by forced orthodontic extrusion of "hopeless" teeth and their periodontal apparatus. By stretching the gingival and periodontal ligament fibers during extrusion, tension is imparted to the entire alveolar socket, stimulating osseous apposition at the alveolar crest. FOE increases the width of the attached gingiva, and the mucogingival junction remains stable when the gingival margin migrates coronally. Based on these effects, FOE of non-restorable teeth prior to implant placement is a viable alternative to conventional surgical augmentative procedures in implant site development. The aim of this case report is to describes coronal soft-tissue augmentation around fractured teeth, which was achieved by FOE before implant placement.

• Korean Journal of Applied Biomechanics
• /
• v.32 no.4
• /
• pp.121-127
• /
• 2022

Objective: The purpose of this study was to investigate potential effects of transcranial direct current stimulation (tDCS) on bimanual force control capabilities in healthy young adults. Method: Eighteen right-handed healthy young adults (10 females and 8 males; age: 23.55 ± 3.56 yrs) participated in this crossover design study. All participants were randomly allocated to both active-tDCS and sham-tDCS conditions, respectively. While receiving 20 min of active- or sham-tDCS interventions, all participants performed bimanual isometric force control tasks at four submaximal targeted force levels (i.e., 5%, 10%, 15, and 20% of maximal voluntary contraction: MVC). To compare bimanual force control capabilities including force accuracy, variability, and regularity between active-tDCS and sham-tDCS conditions, we conducted two-way repeated measures ANOVAs (2 × 4; tDCS condition × Force levels). Results: We found no significant difference in baseline MVC between active-tDCS and sham-tDCS conditions. Moreover, our findings revealed that providing bilateral tDCS including anodal tDCS on left primary motor cortex (M1) and cathodal on right M1 while conducting bimanual force control trials significantly decreased force variability and regularity at 5%MVC. Conclusion: These findings suggest that providing bilateral tDCS on M1 areas may improve bimanual force control capabilities at a relatively low targeted force level.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2020.11a
• /
• pp.45-46
• /
• 2020

최근 의료데이터의 표준화를 기반으로 다양한 임상연구가 국내외에서 활발하게 진행되고 있다. 그러나 대부분 개발기술이 임상현장에 적용되지 못하는 이유는 상이한 인프라로 인한 일관성있는 결가를 도출하지 못하는 문제점과 부족한 진단지표와 기준 그리고 충분하지 못한 기술적·임상적 검증이 문제가 되고 있다. 본 논문에서는 이러한 문제점을 해결하기위한 새로운 통합 플랫폼을 제안하고자 한다. 이를 위해서 임상데이터는 OHDSI의 OMOP-CDM으로 표준화되어야 하며, 이외에 의료영상 정보를 포함한다. 제안한 플랫폼은 표준화된 데이터를 통해 지속적인 자가 학습을 수행하며, 질환별 진단에 필요한 개발 도구와 분석 소프트웨어 도구를 통해 다양한 타겟 질환연구를 지원한다. 제안한 플랫폼은 질환에 대한 비침습적 진단을 위해 의료영상을 기반으로 데이터표준화을 기반으로하며, 이를통해 인공지능 기술을 개발하고 병원 정보시스템과 연계하여 임상현장에 실증을 통해 검증하고자 한다.

• Journal of the Korean Society of Visualization
• /
• v.21 no.2
• /
• pp.14-23
• /
• 2023

The pressure difference across stenotic blood vessels is a commonly used clinical metric for diagnosing many cardiovascular diseases. At present, most clinical pressure measurements rely solely on invasive catheterization. In this study, we propose a novel method for non-invasive pressure estimation using the incompressible Navier-Stokes equations and a 3D multi-path integration approach. We verify spatio-temporal convergence on an in-silico dataset of a cylindrical straight pipe phantom with steady and pulsatile flow fields. We then evaluate the proposed method on an in vitro dataset of reconstructed control, pre-operative, and post-operative carotid artery cases acquired from 4D flow MRI. The performance of our method is compared to existing approaches based on the pressure Poisson equation and work-energy relative pressure. The results demonstrate the proposed method's high accuracy, robustness to spatio-temporal subsampling, and reduced sensitivity to noise, highlighting its great potential for non-invasive pressure estimation.

• Journal of Korean Neuropsychiatric Association
• /
• v.57 no.2
• /
• pp.119-132
• /
• 2018

Despite the fact that pharmacotherapy depressive disorders have proven efficacy, a substantial number of patients are resistant to conventional management. As neuroscientific research about pathophysiology of depression have accumulated, repeated transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have emerged as an important mechanism-based treatment modality. This overview provides a review of therapeutic application of rTMS and tDCS in patients with depression. The clinical and basic studies of rTMS and tDCS in depression were reviewed and integrated using a literature review and interview with experts. rTMS is a noninvasive procedure of a localized pulsed magnetic field to the surface of the head to cause a depolarization of neurons in the brain cortex. tDCS has a mechanism of modulating cortical excitability in a polarity-specific manner without eliciting action potentials. rTMS and tDCS seem promising for treating depression. Although therapeutic parameters and further technical improvement remain to be systematically investigated, rTMS and tDCS would be a safe and effective intervention to treat depression.

• The Korean Journal of Applied Statistics
• /
• v.36 no.5
• /
• pp.361-380
• /
• 2023

Magnetoencephalography (MEG) is a technique to record oscillatory magnetic fields coming from ongoing neuronal activity. Functional brain activities performing cognitive or physiological tasks are performed on structural connections between neurons or brain regions. MEG data can be characterized as highly correlated, spatio-temporal, multidimensional, multilayered dynamic networks. Due to its complex structure, many studies on MEG network have not yet been conducted. In this study, we will explain the concept, necessity, and possible approaches of MEG network analysis. We reviewed the characteristics of MEG data. Network measures and potential network models in MEG and clinical studies are also reviewed.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2024.01a
• /
• pp.17-18
• /
• 2024

악성 흉수의 진단은 세포학적 검사로 암세포를 확인하는 것이 필수적이며 진단율은 50~80%로 나타난다. 양성자 단층 촬영은 비침습적으로 암 병기를 평가하는 유용한 방법이다. 하지만 암이 아닌 다른 원인으로 인한 포도당 대사로 인하여 양전자 단층 촬영만으로 악성 흉수를 진단하는 데 어려움이 있다. 악성 흉수 자동 진단 모델은 암세포를 진단하는데 있어서 보조적인 역할이 가능하다. 이에 따라 본 연구는 컨볼루션 신경망 기반의 딥러닝 모델을 개발하여 악성 흉수 진단 성능을 확인하고 진단의 보조적 목적으로써 딥러닝의 사용 가능성을 확인하고자 하였다. 결과적으로 모델 전반적으로 accuracy 0.7~0.86의 높은 성능을 보였다. 본 연구의 결과를 통해 실제 의료 환경에서 악성 흉수를 진단하는데 딥러닝 모델이 보조적인 역할을 할 수 있을 것으로 기대된다.