신경근전기자극에 의한 척수운동신경원의 흥분성 변화

이정우,김태열,이인학,이준희,Lee, Jeong-Woo,Kim, Tae-Youl,Lee, In-Hak,Lee, Joon-Hee 대한임상전기생리학회 2003 대한임상전기생리학회지 Vol.1 No.1

The purpose of this study was to determine the effect of neuromuscular electrical stimulation(NMES) on the alteration of spinal motor neuron excitability. In this article, I would like to experiment on a standard capacity of clinical electrophysiology, a difference in applying methods and a clinical efficiency of NMES by Nerve conduction velocity. We used normal eight subjects without neuromuscular disease and all subjects participated 3 session, which at least 1 week between session. Participants classified according to each group in Antagonist, Agonist, Antagonist-Agonist by the NMES. The test was measured continuously pre test, post-test, post 20 minute test by EMG including H reflex, F wave, motor nerve conduction velocity(MNCV). The following results were obtained; 1. H-reflex latencies and H/M intervals were significantly increased in agonist and antagonist-agonist group(p<.01). 2. H-reflex amplitudes and H/M ratios were significantly decreased in agonist and antagonist-agonist group(p<.01). In agonist group, H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. 3. F-wave latencies were significantly increased in agonist and antagonist-agonist group(p<.01). F/M intervals were significantly increased in antagonist-agonist group(p<.01). F wave conduction velocities were significantly increased in agonist and antagonist-agonist group(p<.01) but F/M ratios were not significant. 4. MNCV were significantly decreased in agonist(p<.01). These results lead us to the conclusion that agonist and Antagonist-agonist was significantly decreased excitability of spinal motor neuron. Conversely, Antagonist does not decreased. Therefore, A further direction of this study will be to provide more evidence that NMES have an effect on excitability of spinal motor neurons in UMN syndrome.

MR Polishing을 이용한 커버글라스의 굽힘강도 향상에 관한 연구

이정우,김지훈,임동욱,하석재,Lee, Jeong-woo,Kim, Ji-Hun,Lim, Dong-Wook,Ha, Seok-Jae 한국금형공학회 2022 한국금형공학회지 Vol.16 No.1

Coverglass of electronic equipments is thinner and slimmer, so the glass must have good bending strength. In these days, the polishing edge of glass is used by solid tool like grinding wheel. But solid tool leave micro crack or edge chipping in edge of glass. MR polishing is an optimal method by polishing edge of glass. MR polishing is used MR fluid that is a liquid tool. MR polishing doesn't leave tool path or residual stress, micro crack and edge chipping unlike grinding wheel polishing. In this paper, the results of grinding and MR polishing were compared and analyzed to improve bending strength by minimizing edge chipping of cover glass. It was derived that the depth and size of cracks have a significant influence on the bending strength of the glass edge. The edges of the glass using MR grinding were analyzed to have a better surface and higher bending strength than the glass using abrasive wheel grinding. It was confirmed that MR polishing had an effect on strength improvement by effectively removing cracks in the specimen.

논문편 : 신세대 기혼남녀의 라이프스타일 및 가정경영의식

이정우,김명자,계선자,박미석,지금수,김경숙,이정숙,박미금 ( Jeong Woo Lee,Myung Cha Kim,Sun Ja Kye,Mee Sok Park,Keum Soo Chi,Kyung Sook Kim,Jung Sook Lee,Mi Kum Park ) 대한가정학회 1996 Human Ecology Research(HER) Vol.34 No.6

자외선 조사로 유발된 피부 염증성 반응에 맥동성 초음파가 미치는 영향

이정우,박수지,윤세원,Lee, Jeong-Woo,Park, Su-Ji,Yoon, Se-Won 대한물리치료학회 2011 대한물리치료학회지 Vol.23 No.4

Purpose: This study aims to examine the effects of pulsed ultrasound on skin inflammatory reaction induced by ultraviolet irradiation. Methods: Twenty subjects were selected for this study. Inflammatory reaction was induced by ultraviolet irradiation in two areas of the lumbar region of the subjects. Pulsed ultrasound (3 MHz) was applied to one of the two areas of inflammatory reaction at a pulse ratio of 1:4, intensity of $0.5W/cm^2$, once a day for 5 min, and pulsed ultrasound was not applied to the other area. Wound color (chromatic red), luminance (gray) and wound contraction (area) were measured using digital imaging processing method. Results: There was a significant difference in wound color (chromatic red) in the interaction between time and area. There was a significant difference in luminance in the interaction between time and area. There was a significant difference in wound contraction between the two areas. Conclusion: These results indicate that pulsed ultrasound increased the wound contraction rate and reduced the inflammatory reaction activity such as erythema induced by ultraviolet irradiation.

신경근전기자극에 의한 H 반사의 변화

이정우,김태열,Lee, Jeong-Woo,Kim, Tae-Youl 대한물리치료과학회 2003 대한물리치료과학회지 Vol.10 No.1

The purpose of this study was to determine whether neuromuscular electrical stimulation(NMES), applied over the antagonist or the agonist, would alter the H reflex. Attention was focused on the roles of stimulus location. We used normal eight subjects without neuromuscular disease which were divided into 3 groups; the subjects were diveded into group of antagonist, agonist, antagonist-agonist. All groups were meted of eight subjects. Neuromuscular electrical stimulation was administered for 15 minutes. All subjects were subjected to three tests, including a pre-test, post-test and post-20 minute test. The data were analyzed by repeated measures ANOVA and paired t-test. The results were as follows; 1. H latencies were significantly increased in agonist and antagonist-agonist group (p<.01). 2. H/M intervals were significantly increased in agonist and antagonist-agonist group (p<.01). 3. H amplitudes were significantly increased in agonist (p<.001) and antagonist-agonist group (p<.01). 4. H/M ratios were significantly decreased in agonist and antagonist-agonist group (p<.01). In agonist group. H-reflex amplitudes and H/M ratios were more significantly decreased than antagonist group. Future studies will need to determine what influence NMES may have on the excitability of spinal motor neurons in people having UMN syndrome.

자기 부상 실습 장치의 개발에 관한 연구

이정우,정연두,한명근,Lee Jeong-Woo,Cheong Yeon-Doo,Han Myoung-Keun 한국공학교육학회 2005 공학교육연구 Vol.8 No.1

이 논문은 삼척대학교 메카트로닉스 공학부에서 자동제어, 디지털제어, 마이크로 프로세서응용의 실습을 위해 사용되는 자기 부상실습장치의 설계와 제작에 관한 것이다. 이 장치는 MIT 대학의 설계에서 영감을 받아 개발되었으나, MIT의 장치가 아날로그형임에 비해 디지털형으로 개발하였다. 이 실습장치는 아날로그와 디지털 방식으로 동시에 제어하고 모니터할 수 있다. 더구나 부품의 가격은 MIT의 것과 비슷하거나 더 싼 편이다. 그리고 이 장치는 자기 홀 센서나 적외선 센서를 이용하여 제어할 수 있어서 학생들에게는 센서의 사용과 신호처리를 위한 다양한 경험을 얻을 수 있도록 되어있다. 이 설계는 저자들이 제작하여 시험해 보았으며, 학생들에게 실험 프로젝트 형식으로 제공될 것이다. 이 장치는 의도적으로 덜 보상되어지고, 적당한 수준까지만 조립된 상태에서 학생들에게 제공될 것이며, 학생들은 센서신호와 제어기의 성능을 분석한 후 보상기를 설계하고 센서의 신호를 처리할 것이 기대된다. This paper describes the design and fabrication of magnetic levitation kits for use in the hands on experiments of automatic control, digital control and microprocessor applications in the division of mechatronics in Samcheok university. The kits are developed inspired by MIT's design, but it is designed on the digital basis, whereas MIT's is designed on the analog basis. As a result, the kits can be monitored and controlled on the analog and digital control techniques. Furthermore, the cost of kit components is comparable or lower to that of MIT design. And the kits can be controlled with magnetic hall sensors and/or infrared sensors, which provides more versatile experience on the use of sensors and signal filtering to the students. The design is fabricated and tested by authors and will be provided to the students as lab projects. The kits will be intentionally presented with a device that is poorly instrumented and poorly compensated. And the students are expected to analyze sensor signal and controller performance, and then, perform compensator design and signal filtering.

논문편 : 신세대 기혼남녀의 라이프스타일 , 가정경영의식 및 행동

이정우,김명자,계선자,박미석,지금수,김경숙,이정숙,박미금 ( Jeong Woo Lee,Myung Cha Kim,Sun Ja Kye,Mee Sok Park,Keum Soo Chi,Kyung Sook Kim,Jung Sook Lee,Mi Kum Park ) 대한가정학회 1997 Human Ecology Research(HER) Vol.35 No.1

경표피수분손실 및 Methyl Nicotinate 경피흡수에 의한 혈관 반응 측정을 이용한 피부 장벽 기능 검사

이정우,김도원,전재복,정상립 ( Jeong Woo Lee,Jae Bok Jun,Do Won Kim,Sang Lip Chung ) 대한피부과학회 1997 대한피부과학회지 Vol.35 No.6

Background: The measurement of transepidermal water loss(TEWL) is widely used in evaluating the stratum corneum barrier function. It is also possible to evaluate the penetration of substances into the skin as an adc'itional parameter of the straturn corneum barrier function. Objective : The purpose of the present study is to investigate ihe relat,ionship between TEWL and t,he percutaneous absorptic n of met,hyl nicotinate(MN) in the normal and acute perturbative state of the epidermal barrier. Method: Vascular response 10 MN penetration were rneasured by both laser Doppler flowmetry (LDF) and visual erythema oii the forearms of 30 healthy volunteers. Stratum corneum of the ar ea of 2*10cm on the volar for earm was removed by repeated tape stripping when TEWL reached 12-30g/rnh measured with Evaporimeter. The left forearm received no treatrnent as a control site. Each time the profile of the vascular response to MN penetration was analysed using the following parameters.the 1; g time between MN application and initial response(T0), the time between MN application and maximal response(Tmax), and the rnaximal response(LDF), the time between MN application and initial visual erythema(VT0), and the time between MN application and maxirnum visual erythema(VTmax). Results : The data showed a negative correlation between TEWL and T0(r=-12.89, p<0.001), TEWL and Tmax=(r=-14.87, p< 0.001), and TEWL and VT0>(r= -3.99, p<0.001), TEWL and VTmax(r = -9.29, p<0.001). And there was a positive correlation between VT0 and T0(r=1.19, p<0.001), and between VTmax and Tmax(r=1.05, p<0.001). However, there was no detectable correlation between TEWL and LDFmax(p>0.05). Conclusion : Vascular response to percutaneous absorption of MN measured by LDF as well as TEWL is a useful non-invasiv method for objective evaluation of the stratum corneum barrier function. In addition, visual erit,hema induced by t,opical vasodilators such as MN is also a good method for skin barrier function assessment. (Korean J Dermatol 1997;35(6): 1121 1129)

정상 여성에게서 앞 정강근의 수축훈련방법에 따른 뇌파의 변화

이정우,김문정,윤세원,Lee, Jeong-Woo,Kim, Moon-Jeong,Yoon, Se-Won 대한물리치료학회 2012 대한물리치료학회지 Vol.24 No.2

Purpose: This study aims to examine the power changes in eletrocenphalogram (EEG) detected from the tibialis anterior muscle, during repetitive contraction exercise in normal female adults. Methods: The subjects of this study were 24 normal adult females, with no musculoskeletal or nervous system disorders. The 24 female subjects were divided into two groups: 12 subjects comprised a voluntary stimulation training group, and the other 12 subjects comprised an electrical stimulation training group. A total of thirty contractions were made repetitively by each woman, with maximal voluntary contraction exercise for six seconds, and a resting time of three seconds. During the experiment, their EEG was measured at eight positions. The eight positions were Fpz, Fz, Cz, CPz, C3, C4, P3, and P4, in accordance with the international 10~20 system. Results: The relative alpha power and beta power showed no statistically significant differences between the two groups. But the relative gamma power of the CPz, C3, C4, P3, and P4 areas showed statistically significant differences between the two groups (p<0.05). The relative theta power of the C4 area showed statistically significant differences between the two groups (p<0.05). Conclusion: Our findings show that tibialis anterior muscle contraction by electrical stimulation and by voluntary repeated contraction differentially affected brain activation. In particular, the CPz, C3, C4, P3 positions of relative gamma power showed brain activation in voluntary contraction. The C4 position of relative theta power showed different brain activation between the two groups.

전기생리학적 기전에 근거한 망막 모델의 제안과 시공간적 응답의 분석

이정우,채승표,조진호,김명남,Lee, Jeong-Woo,Chae, Seung-Pyo,Cho, Jin-Ho,Kim, Myoung-Nam 대한전자공학회 2002 電子工學會論文誌-SC (System and control) Vol.39 No.6

본 논문에서는 망막의 전기생리학적 기전을 바탕으로 실제 망막과 유사한 기능 및 응답 특성을 갖는 망막 모델을 제안하였다. 시세포에서 양극세포까지는 기존에 연구된 여러 망막 모델들을 종합하여 모델링하였고, 3 NDP 기전을 이용하여 움직임 정보를 검출한다고 알려져 있는 아마크린세포와 양극세포 터미널에 관한 새로운 모델을 제안하였다. 이 모델의 평가를 위하여, 공간상의 동적 자극과 정지 자극에 대한 응답 특성을 비교 분석을 하였을 뿐만 아니라 자극의 움직임 속도에 따른 특성에 대한 분석도 수행하여 제안한 망막 모델을 검증하였다. 본 연구결과는 움직임 정보를 검출하기 위한 비전 시스템에 대한 인간 시각 시스템의 적용 및 생체에 이식할 수 있는 인공 망막의 개발을 위한 기초 연구에 이용될 수 있을 것이다. Based on electrophysiological retina mechanism, a retina model is proposed, which has similar response characteristics compared with the real primate retina. Photoreceptors, horizontal cells, and bipolar cells are modeled based on the previously studied retina models. And amacrine cells known to have relation to movements detection, and bipolar cell terminals are newly modeled using 3 NDP mechanism. The proposed model verified by analyzing the spatial response characteristics to stationary and moving stimuli, and characteristics for different speeds. Through this retina model, human vision system could be applied to computer vision systems for movement detection, and it could be the basic research for the implantable artificial retina.