폴리머/ 금속 다층 공정 기술을 이용한 실시간 혈압 모니터링을 위한 유연한 생체 삽입형 센서

임창현,김용준,윤영로,윤형로,신태민,Lim Chang-Hyun,Kim Yong-Jun,Yoon Young-Ro,Yoon Hyoung-Ro,Shin Tae-Min 대한의용생체공학회 2004 의공학회지 Vol.25 No.6

본 논문에서는 폴리머/ 금속 다층 공정 기술 (polymer/metal multi layer processing techniques)을 이용한 실시간 혈압 감지를 위한 유연한 생체 삽입형 센서를 새로이 제안한다. 제안되는 방식의 센서는 기계적으로 유연하기 때문에 혈관의 외벽에 대한 침습성을 감소시켜 부착할 수 있다. 즉, 혈압 측정을 위해 센서를 혈관 내에 설치하던 기존의 방법들에 비해서 혈관 자체에 상처를 주지 않고 혈압의 상대적인 변화를 지속적으로 감지할 수 있다. 성인에게 발생하는 급사의 주된 원인은 협심증, 심근 경색과 같은 혈관 관련 질환이다. 플라크 (plaque)의 생성 등과 관계된 순환계 관련 질환들은 지속적인 혈압 감지를 통해서 예방할 수 있으며 발병 초기에 치료할 수 있다. 본 연구에서 제안하는 혈압감지 방법의 과정은 다음과 같다. 우선, 집적된 센서를 혈관 외벽에 부착한다. 둘째, 실장된 센서가 혈관의 기계적인 수축과 확장을 인식한다. 마지막으로, 센서에 의해 인식된 혈압의 변화를 원격 감지 방법을 통해서 외부 안테나에서 감지하게 된다. 센서 시스템에는 어떠한 능동 소자도 존재하지 않기 때문에 에너지와 혈압 변화 정보는 LC 공진기와 외부 안테나 사이에 발생하는 상호 인덕턴스 원리에 의해서 전달되게 된다. 이러한 측정 원리의 가능성을 확인하기 위해서 실리콘 고무관과 혈액을 이용하여 시험관 실험 (In vitro test)을 진행하였다. 우선, 혈액으로 채운 실리콘 고무관에 센서를 감은 후 피스톤으로 압력을 가하였다. 그리고 이를 통해 가해진 압력 변화에 따른 공진 주파수의 변화를 측정하였다. 가해진 압력이 0부터 213.3 KPa까지 변화하는 동안 2.4 MHz의 공진 주파수가 변했다. 그러므로 생체 삽입형 혈압 센서의 감도는 11.25 KHz/KPa이다. Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

수치해석을 통한 커튼 에어백의 측면 충격 및 이탈 경감 성능 평가 방법에 대한 연구

임창현(Chang-Hyun Lim),조재순(Jae-Soon Cho),곽대영(Dae-Young Kwak),조영남(Young-Nam Cho) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

It is well known that the curtain airbag is one of most effective devices to protect occupant from being fatally injured during rollover and side impact crash situations. The main purpose of this study is to establish design standards and requirements of curtain airbags for both rollover and side impact protections on the component level. For this, three stages of study were conducted in the present investigation. First, three SUV vehicles with curtain airbags were selected and base models were established by MADYMO software. Second, various numerical simulations of curtain airbags including the linear impact were performed and Pressure vs. Thickness map was established. Finally, various numerical simulation studies for different containment conditions were performed and the results were compared in terms of severity. From these approaches, part design standards and requirements of the curtain airbags were successfully established.

Far-side 충돌에 관한 연구동향 및 에어백 개발 연구

임창현(Lim Chang Hyun),곽대영(Gwak Dae Young),이승훈(Lee Seung Hoon),권태익(Kwon Tae Ik) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

골격근의 혈류차단 후 재 관류 시 운동훈련의 형태가 골격근 재생 및 회복에 미치는 영향

임창현 ( Chang Hyun Lim ),김창근 ( Chang Keun Kim ) 한국운동생리학회(구 한국운동과학회) 2017 운동과학 Vol.26 No.1

PURPOSE: The present study examined the effect of two-week resistance and endurance training on skeletal muscle repair and regeneration after ischemia-reperfusion (IR) injury in rat. METHODS: Ten week-old male Sprague-Dawley (SD) rats were divided into three groups (IR-CON, IR-RE, IR-EN). To evaluate different property of muscle types, soleus (SOL) and extensor digitorum longus (EDL) muscle were dissected. We conducted confocal microscope experiment and western blot for evaluating cell cycle of skeletal muscle repair and regeneration. RESULTS: Satellite cells (SC) of SOL and EDL muscle were markedly increased after both exercise training. However myonuclear was only increased on SOL muscle. MyoD protein expression in SOL and EDL was increased after endurance exercise training. CONCLUSIONS: It is consider that exercise training after IR injury may affect to repair and regeneration of damaged skeletal muscle positively by increasing SC and myonuclear in all exercise training, despite a little different response follow muscle types.

21세기 전후 한국 현대건축에 나타난 ‘전통성’에 관한 연구 - 케네스 프램톤의 "비평적 지역주의’ 관점으로 -

임창현(Lim, Chang-Hyun),서명수(Seo, Myeng-Soo) 대한건축학회 2020 대한건축학회 학술발표대회 논문집 Vol.40 No.1

This research explores the traditionality on Korean Modern Architecture around the 21st century. The introduction of modern architecture in Korea had solved the housing problems after the Koran War through providing enough housings in a short time. However, these modern buildings, which were built after the 1950s with only Western-style and technologies, were insufficient containing architecture"s identity. Therefore, Korean architecture had lost its original traditionality and regionality because these modern buildings were built without considering the criticism and solving environmental problems in Korean context. This lack of traditionality and regionailty in Korean architecture had been discussed since the 1960s from a few Korean architects, but they had a hard time in incarnating Korean architecture"s identity due to the economy-first policy until 1980s. However, from the 1990s a few Korean pioneering architects such as the 4·3 Group began to seriously think about synthesizing the traditionality and modernity. This study tried to find out how “traditionality” is expressed in among modern architecture after 1990s. In order to find the originality and its characteristics, this research were conducted mainly on public buildings and houses expressing "traditionality" built since 1990s. Through this, this research tried to examine the traditional design elements of modern architecture, in which internationalism and tradition are dialectically viewed. Moreover, these buildings were reviewed from the perspective of Kenneth Frampton"s “Critical regionalism” which played a significant tole in reflecting the identity of architecture from the 1980s in the West. This study helps Korean architecture establish principles in the traditional element of architectural design, and further to establish Korean architecture"s identity between the tradition and modernity.

Impact of Soil Salinity on CH4 Production in Coastal Reclaimed Land

Chang Hyun Lim(임창현),Sang Yoon Kim(김상윤),Jessie Gutierrez(제시구티어레즈),Pil Joo Kim(김필주) 한국토양비료학회 2010 한국토양비료학회 학술발표회 초록집 Vol.2010 No.5

연구본문 : 토양환경 ; 간척지 논 토양의 염 농도가 메탄 배출에 미치는 영향

임창현 ( Chang Hyun Lim ),김상윤 ( Sang Yoon Kim ),정승탁 ( Seung Tak Jeong ),김건엽 ( Gun Yeob Kim ),김필주 ( Pil Joo Kim ) 한국환경농학회 2013 한국환경농학회지 Vol.32 No.4

간척지 논 토양에서 염 농도에 따른 메탄 배출특성을 조사 하기 위하여 포트 실험을 실시한 결과, 염 농도의 증가는 메탄 배출량 감소와 벼 생육 및 수량성악화에 영향을 주는 것으로 조사되었다. 벼 재배기간 중 높은 EC와 pH로 인한 메탄생성균의 활성 감소와 벼 생육 악화에 따른 메탄 배출량 감소가 주요 원인으로 평가되었다. 토양의 EC와 pH는 총 메탄 배출량과 고도의 부의 상관관계를 나타내었으며, 벼 생육(초장 및 분얼)과는 정의 상관관계를 나타내었다. 하지만 주로 높은 EC에 의한 메탄 저감효과는 벼의 생육 초기에 대부분 나타났으며, 생육 후기로 갈수록 염의 희석효과에 의하여 저감효과가 크게 감소되는 것으로 확인하였다. 본 연구의 결과를 통하여 간척지 논 토양의 염 농도가 메탄 배출량에 감소에 큰 영향을 줄 수 있는 것으로 평가되며, 간척지 논 토양에서 메탄 배출량 평가 또는 예측에 좋은 자료로 활용될 수 있을 것으로 판단된다. BACKGROUND: Salt accumulation in coastal reclaimed soil can decrease plant growth and productivity, which could lead to considerable variation of methane(CH4) emission in a rice paddy. The objective of this study was to evaluate the effect of salt concentration on CH4 emission in a coastal reclaimed soil. METHODS AND RESULTS: The effect of salt concentration on CH4 emission and rice growth characteristics was studied by pot test, which packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Electrical conductivity (EC) of each treatment was controlled by 0.98, 2.25, 5.05 and 9.48 dS/m and CH4 emission was characterized a week interval by closed chamber method during rice cultivation. The CH4 emission rate was significantly decreased with increase of salt accumulation, but total CH4 flux in EC 5.50 dS/m treatment was lower than those of EC 9.48 dS/m treatment. It seems because of higher content of water soluble SO4 2- in EC 5.50 dS/m treatment than those of EC 9.48 dS/m treatment. Rice growth and grain yield were significantly decreased with increase of salt accumulation. Soil properties, especially EC and pH were negatively correlated with CH4 flux, while rice growth characteristics like plant height and tiller number show significantly positive correlation with CH4 flux. CONCLUSION(S): Conclusively, salt accumulation significantly decreased CH4 flux in a rice paddy, which could be useful information for evaluating CH4 flux in reclaimed area in Korea.

홍역과 동반된 각막염

임창현 ( Chang Hyun Lim ),배선량 ( Sun Ryang Bae ),이규일 ( Kyoo Il Lee ) 대한안과학회 2002 대한안과학회지 Vol.43 No.11

일회성 저강도 고반복 저항성 운동이 골격근 합성신호 단백질 발현 및 위성세포 활성에 미치는 영향

임창현 ( Chang-hyun Lim ),김창근 ( Chang-keun Kim ) 한국운동생리학회(구 한국운동과학회) 2020 운동과학 Vol.29 No.1

PURPOSE: Previous studies have reported that low-load high-repetition (LLHR) resistance exercise can induce muscle hypertrophy to a similar extent as high-load low-repetition (HLLR). However, it is unclear which mechanical stress, such as exercise intensity, contraction number, and/or total work volume and which molecular mechanisms underpin the greater relative muscle hypertrophy after LLHR exercise. METHODS: Sprague-Dawley rats (12 weeks, N=35) were randomly allocated into control (Con, n=7), low-load low-repetition (LLLR, n=7), low-load medium-repetition (LLMR, n=7), LLHR (n=7), and HLLR (n=7) resistance exercise groups. They performed a ladder climbing exercise to evaluate the effect of exercise intensity, contraction number and work volume on the activation of satellite cells and protein synthesis signaling pathway. RESULTS: The number of active satellite cells and the phosphorylation of mTOR, p70S6K, ERK, and p38 were increased after LLHR and HLLR exercise (p<.005). However, phosphorylation of 4E-BP1 was only increased after the LLHR exercise (p<.05). CONCLUSIONS: Acute low load exercise accompanied by high total work volume may activate muscle protein synthesis mechanisms for hypertrophy similar to high load resistance exercise.

연구보문 : 토양환경 ; 간척지 논 토양 개량제로서 석고처리가 메탄 배출량 저감에 미치는 영향

임창현 ( Chang Hyun Lim ),김상윤 ( Sang Yoon Kim ),김필주 ( Pil Joo Kim ) 한국환경농학회 2011 한국환경농학회지 Vol.30 No.3

BACKGROUND: Gypsum(CaSO4·2H2O) is known as an ideal amendment to improve soil quality of the reclaimed coastal land. Since gypsum has very high concentration of electron acceptor like SO4(2-), its application might be effective on reducing CH4 emission during rice cultivation, but its effect has not been studied well. METHODS AND RESULTS: The effect of gypsum on CH4 emission and rice growth characteristics was studied by pot test, which was packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Chemical-grade gypsum was applied in two soils having EC 2.25 and 9.48 dS/m at rates of 0, 0.5, 1.0 and 2.0%(wt/wt). CH4 emission was characterized a week interval by closed chamber method during rice cultivation. CH4 emission rate was significantly decreased with increasing salt accumulation and gypsum application levels. With increasing gypsum application, dissolved SO4(2-) concentration in the leachate water was significantly increased, which might have suppressed CH4 production in soil. Total CH4 flux was dramatically decreased with increasing gypsum application. In contrast, rice yield was increased with increasing gypsum application and then achieved maximum productivity at 1.0% gypsum application in two soils. CONCLUSION(s): Gypsum is a very good soil amendment to suppress CH4 emission in reclaimed coastal paddy soils, and improve rice productivity and soil properties. The optimum application level of gypsum is assumed at ca. 1% to improve soil productivity with reducing effectively CH4 emission during rice cultivation.