• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1450-1454
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• 2008

In the conventional biology, the most of cell studies was carried out by culturing cells in the Petri dish and by investigating cellular behavior under the diverse bio-molecule (cell signalling materials, drugs or etc.) conditions. However, in vivo environments, diverse stimulations including chemical, mechanical and topological environments involved in the proliferation, differentiation and migration of cells and it is almost impossible to provide these conditions with traditional method. We have developed the methods to provide the well defined chemical and mechanical stimulations using microfluidic devices and applied these approaches to the study of environmental effect on cells. In this paper, we will introduce our microfluidic chips to provide microenvironment and its applications using several cells.

• Journal of International Society for Simulation Surgery
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• 제2권1호
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• pp.40-42
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• 2015

Purpose Usability is an important factor in our life. This paper presents an approach to design the clinical work-flow for ultrasound system. And, we tried to apply this work-flow in diagnosis ultrasound system. Materials and Methods For user learnability, we follow international standard IEC 60601-1-1 and IEC 62366 which describes usability of medical instrument. User requirement are applied by 10 clinicians who are well aware of usability. We considered user environment and designed clinical work-flow into two types: general use and emergency use. The designed clinical work-flow was evaluated by 10 clinicians and results derived from the evaluation were analyzed. Results We could successfully design optimized clinical workflow of ultrasound system. Conclusion This paper suggests usability testing for optimized ultrasound clinical workflow. Using this clinical work flow, users can enhance their clinical performance and reduce operation time.

• Journal of Power Electronics
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• 제13권6호
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• pp.985-990
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• 2013

This paper proposes a novel fault diagnosis scheme using parameter estimation of the stator resistance, especially in the case of the open-phase faults of PMSM drives. The stator resistance of PMSMs can be estimated by the recursive least square (RLS) algorithm in real time. Fault diagnosis is achieved by analyzing the estimated stator resistance of each phase according to the fault condition. The proposed fault diagnosis scheme is implemented without any extra devices. Moreover, the estimated parameter information can be used to improve the control performance. The feasibility of the proposed fault diagnosis scheme is verified by simulation and experimental results.

• 센서학회지
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• 제31권2호
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• pp.79-84
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• 2022

Self-powered sensors play an important role in everyday life, and they cover a wide range of topics. These sensors are meant to measure the amount of relevant motion and transform the biomechanical activities into electrical signals using triboelectric nanogenerators (TENGs) since they are sensitive to external stimuli such as pressure, temperature, wetness, and motion. The present advancement of TENGs-based self-powered wearable, implantable, and patchable sensors for healthcare monitoring, human body motion, and medication delivery systems was carefully emphasized in this study. The use of TENG technology to generate electrical energy in real-time using self-powered sensors has been the topic of considerable research among various leading scholars. TENGs have been used in a variety of applications, including biomedical and healthcare physical sensors, wearable devices, biomedical, human-machine interface, chemical and environmental monitoring, smart traffic, smart cities, robotics, and fiber and fabric sensors, among others, as efficient mechanical-to-electric energy conversion technologies. In this evaluation, the progress accomplished by TENG in several areas is extensively reviewed. There will be a discussion on the future of self-powered sensors.

• 대한치과교정학회지
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• 제54권2호
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• pp.79-88
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• 2024

Objective: Alveolar bone loss is a common adverse effect of intrusion treatment. Mandibular incisors are prone to dehiscence and fenestrations as they suffer from thinner alveolar bone thickness. Methods: Thirty skeletal class II patients treated with mandibular intrusion arch therapy were included in this study. Lateral cephalograms and cone-beam computed tomography images were taken before treatment (T1) and immediately after intrusion arch removal (T2) to evaluate the tooth displacement and the alveolar bone changes. Pearson's and Spearman's correlation was used to identify risk factors of alveolar bone loss during the intrusion treatment. Results: Deep overbite was successfully corrected (P < 0.05), accompanied by mandibular incisor proclination (P < 0.05). There were no statistically significant change in the true incisor intrusion (P > 0.05). The labial and lingual vertical alveolar bone levels showed a significant decrease (P < 0.05). The alveolar bone is thinning in the labial crestal area and lingual apical area (P < 0.05); accompanied by thickening in the labial apical area (P < 0.05). Proclined incisors, non-extraction treatment, and increased A point-nasion-B point (ANB) degree were positively correlated with alveolar bone loss. Conclusions: While the mandibular intrusion arch effectively corrected the deep overbite, it did cause some unwanted incisor labial tipping/flaring. During the intrusion treatment, the alveolar bone underwent corresponding changes, which was thinning in the labial crestal area and thickening in the labial apical area vice versa. And increased axis change of incisors, non-extraction treatment, and increased ANB were identified as risk factors for alveolar bone loss in patients with mandibular intrusion therapy.

• 마이크로전자및패키징학회지
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• 제28권2호
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• pp.13-28
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• 2021

트랜지언트 전자소자는 전해질 수용액이나 체내와 같은 거친 환경에서도 작동이 가능하며 동작 이후 가수분해되어 스스로 제거되기 때문에 기존의 전자소자를 대체하여 의료 목적의 체내 삽입 소자 등 다양한 연구 영역에서 활용되고 있다. 또한 물과 효소만으로 제거가 가능한 트랜지언트 전자소자는 최근 대두되고 있는 전자 쓰레기와 환경 오염 문제를 해결할 수 있는 신개념 그린 테크놀로지로 많은 주목을 받고 있다. 하지만, 트랜지언트 전자소자의 작동 환경인 수용액과 체내는 지속적은 물 침투를 통해 소자 내 핵심 부품을 열화시킨다. 이러한 환경 내 안정한 동작을 위하여 수동적 보호 기능을 가진 피막이 소자 외부를 감싸는 봉지막 전략이 도입되었다. 본 논문에서는 트랜지언트 전자소자의 등장 배경과 분해 거동을 포함한 최근 연구 동향과 작동 환경 내 물 침투를 방지하여 동작 신뢰도를 향상시킬 수 있는 봉지막 전략에 관하여 정리하였다.

• 대한의용생체공학회:의공학회지
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• 제41권6호
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• pp.256-263
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• 2020

The importance of quality control has been emphasized to maintain safety of patients and satisfaction of medical service with medical devices used in clinic. Accordingly, objective evaluation method and standards consistently has been brought up for demand to replace outdated medical devices in appropriate time and to maintain the quality of medical service. Though many studies made suggestions methods to determine what medical devices to be replaced first, these methods were difficult in practice for its complex evaluation criteria and long time to evaluate. Therefore, in this study, a simple evaluation method is developed to identify and prioritize medical devices that are ought to be replaced. For the development of this simple evaluation method, four major characteristics of technology, safety, finance, and user satisfaction, which are considered in clinics to evaluate medical device replacement, and 14 minor attributes are distinctively selected. Each characteristic is assessed in binary form of "YES" or "NO" to minimize its subjective nature. Using this method to evaluate sampled medical devices belonging to four different characteristics, devices are suggested to be replaced in the current financial year or in the following financial year, or re-evaluated by the end of this financial year. Such results of evaluation can amend the subjective nature of existing evaluation method and give objective standards more promptly.

• 문화기술의 융합
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• 제8권5호
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• pp.1-7
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• 2022

한국의 의료기기 산업은 1995년부터 시작된 G7 의료공학기술개발사업으로 본격적인 성장과 발전의 기틀을 마련하였으며 2020년 한국 의료기기 생산실적은 2001년에 비하여 8.52배, 수출 실적은 13.94배 성장하였다. 의료기기 국산화 개발 초기에 초음파 의료기기 등 전자 의료기기의 개발이 활발하였던 것과 비교하여 2020년에는 체외진단시약과 치과용 임플랜트의 생산 및 수출 실적이 상위권을 차지하고 있다. 그러나 한국 의료기기 시장에서 수입 의료기기가 차지하는 비중은 60-70%에서 큰 변화가 없는데 이는 한국의 의료기기 산업이 중저가 의료기기를 생산 수출하고, 기술집약적이고 자본집약적인 고가 의료기기는 주로 수입에 의존하고 있기 때문이다. 본 논문에서는 한국과 세계시장의 주요 의료기기 회사들의 생산 품목을 비교하여 한국 의료기기 산업의 세계 시장 진출에 대한 전략을 제시하고자 한다.

• 한국정밀공학회지
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• 제28권11호
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• pp.1242-1250
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• 2011

Several biomimetic artificial muscles including the electro-active synthetic polymers (SSEBS, PSMI/PVDF, SPEEK/PVDF, SPSE, XSPSE, PVA/SPTES and SPEI), bio-polymers (Bacterial Cellulose and Cellulose Acetate) and nano-composite (SSEBS-CNF, SSEBS-$C_{60}$, Nafion-$C_{60}$ and PHF-SPEI) actuators are introduced in this paper. Also, some applications of the developed biomimetic actuators are explained including biomimetic robots and biomedical active devices. Present results show that the developed electro-active polymer actuators with high-performance bending actuation can be promising smart materials applicable to diverse applications.

• 대한의용생체공학회:의공학회지
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• 제26권5호
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• pp.309-317
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• 2005

It is expected that fully-implantable middle-ear hearing devices (FIMEHDs) will soon be available with the advantages of complete concealment, easy surgical implantation, and low power operation to resolve the problems of semi-implantable middle-ear hearing devices (SIMEHDs) such as discomfort of wearing an external device and replacement of battery. Over the last 3 years, a Korean research team at Kyungpook National University has developed an FIMEHD called ACRHS-1 based on a differential floating mass transducer (DFMT). The main research focus was functional improvement, the establishment of easy surgical procedures for implantation, miniaturization, and a low-power operation. Accordingly, this paper reviews the overall system architecture, functions, and experimental results for ACRHS-1 and its related accessories, including a wireless battery charger and remote controller.