쥐 뇌 관찰을 위한 망간조영 증강 자기공명영상 최적설계

강지혁 대전대학교 기초과학연구소 2020 自然科學 Vol.31 No.-

Recently, studies using magnetic resonance functional neuroimaging (MRFN) reflecting biochemical, physiologic and electrical properties of brain are actively progressed with rapid development of functional neuroimaging technology. More recently, manganese(Mn2+) -enhanced MRI (MEMRI) has been focused as the method to obtain images of structure and activated parts of the CNS. Mn2+ is well-known to be a microelement acting as an essential component of nutriment metabolism, immunological reaction, bone growth and major enzyme. In addition, due to the fact that Mn2+ can penetrate via voltage-gated calcium channels resulting in excitation of brain cells, Mn2+ would be attempted to be a contrast agent. There are several causes of the attempt to use Mn2+ as: (1) a useful tissue contrast agent, (2) as a surrogate marker for neuronal cell activity, and (3) a tracer of neuronal pathways. However, due to the fact that overdose of Mn2+ can occur severe neurotoxicity, the dose and injection site of Mn2+ ought to be considered.Thus, the construction of method for injecting site of Mn2+ and its optimal dose is drawing attention for the fundamental process of MEMRI study. For such perspective,many studies about injection route and neuronal toxicity of Mn2+, andchanges in signal intensity according to time-course have been conducted. However, clear answer is still an enigma. For this, the present study will be performed to establish optimal dose and injection route of Mn2+, and method for stable acquisition of images of structures and activated parts in the rat brain through MEMRI maintaining physiological condition. If the present study is successful, MEMRI study would be more accessible and useful in neuroimaging study. So, it is anticipated to be a great priming to the development of study on neuroanatomy and neurophysiology

당뇨병성 다발신경병증의 진단을 위한 신경전도검사의 특징 분석

강지혁 대전대학교 기초과학연구소 2017 自然科學 Vol.28 No.-

Nerve conduction studies (NCS) are the most objective measure of nerve function for the diagnosis of sub-clinical neuropathy in diabetic polyneuropathy (DPN). The purpose of this study was to evaluates the characteristic of electrophysiological abnormalities in DPN. Electrodiagnostic data from 120 patients with diabetic polyneuropathies and 77 control subjects were reviewed. Motor nerve conduction velocities (MNCV), compound muscle action potential (CMAP) amplitudes, conduction velocity and the distal amplitude of the compound nerve action potential (CNAP) were analyzed. DPN was systemic demyelinating peripheral polyneuropathy and more severe abnormal nerve conduction was found in lower limbs than in upper limbs. The severity of the abnormal nerve conduction was more apparent in the distal CNAP amplitude than in the conduction velocity. In particular, the sural nerve is the best indicator for the early detection of DPN. These findings have important implications for the electrophysiological evaluation of DPN.

어린선수와 훈련받지않은 대상의 심전도상의 특성의 비교

강지혁,박상구 대한임상검사과학회 2012 대한임상검사과학회지(KJCLS) Vol.44 No.3

The hearts of highly trained athletes show morphologic and electrocardiographic (ECG) changes that suggest the presence of cardiovascular disease, including sinus bradycardia, a striking increase in precordial R-wave or S-wave voltages, ST segment depression, and T-wave inversions. Despite a number of previous observational surveys, the determinants of abnormal ECG patterns in trained athletes remain largely unresolved. In this study, we compared the electrocardiographic characteristics of athletes to determine any sensitive indicators. Comparison between ECG patterns and cardiac physiology was performed in 21 junior athletes and 25 untrained subjects with no signs of cardiac disease. Sinus bradycardia was detected in a subset of athletes but not statistically significant between the athletes (69.9±11.1 bpm) and the control (72.7±9.9 bpm) group.The mean values of the PR and QTc intervals in the athletes’ group were 149.2±15.4 ms and 402.3±28.8 ms, respectively. Also, there were no significantly differences between control group and the athletes’ group. In addition, the athletes demonstrated a spectrum of alterations in the 12-lead ECG pattern, including marked increase in precordial R-wave or S-wave voltages (SV1+RV5 ≧ 35 mm, 23.8%), QRS duration (≧ 90 ms, 90.5%), suggestive of left ventricular hypertrophy. However, left axis deviation, ST segment depression, and T-wave changes in V5, V6 were not observed in either the athletes or control group. Our findings suggest that sinus bradycardia, precordial R-wave or Swave voltages, and QRS duration seem to be more sensitively detected in athletes than in control group. Further researches on the electrocardiographic patterns of athletes should be carried out to improve the sensitivity and specificity of diagnostic criteria. .The hearts of highly trained athletes show morphologic and electrocardiographic (ECG) changes that suggest the presence of cardiovascular disease, including sinus bradycardia, a striking increase in precordial R-wave or S-wave voltages, ST segment depression, and T-wave inversions. Despite a number of previous observational surveys, the determinants of abnormal ECG patterns in trained athletes remain largely unresolved. In this study, we compared the electrocardiographic characteristics of athletes to determine any sensitive indicators. Comparison between ECG patterns and cardiac physiology was performed in 21 junior athletes and 25 untrained subjects with no signs of cardiac disease. Sinus bradycardia was detected in a subset of athletes but not statistically significant between the athletes (69.9±11.1 bpm) and the control (72.7±9.9 bpm) group.The mean values of the PR and QTc intervals in the athletes’ group were 149.2±15.4 ms and 402.3±28.8 ms, respectively. Also, there were no significantly differences between control group and the athletes’ group. In addition, the athletes demonstrated a spectrum of alterations in the 12-lead ECG pattern, including marked increase in precordial R-wave or S-wave voltages (SV1+RV5 ≧ 35 mm, 23.8%), QRS duration (≧ 90 ms, 90.5%), suggestive of left ventricular hypertrophy. However, left axis deviation, ST segment depression, and T-wave changes in V5, V6 were not observed in either the athletes or control group. Our findings suggest that sinus bradycardia, precordial R-wave or Swave voltages, and QRS duration seem to be more sensitively detected in athletes than in control group. Further researches on the electrocardiographic patterns of athletes should be carried out to improve the sensitivity and specificity of diagnostic criteria.

만성염증성탈수초성다발신경병증과 1형 샤르코-마리-투스병의 복합신경활동전위 평가

강지혁 대전대학교 기초과학연구소 2018 自然科學 Vol.29 No.-

Charcot-Marie-Tooth (CMT) disease is the most common cause of inherited peripheral neuropathies and chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disorder that affects myelin sheaths of peripheral nerves. Nerve conduction studies (NCS) are important for classification, diagnosis, and understanding of them. The aim of this study was to analyze and compare compound nerve action potential results between two groups of patients for differential diagnosis. The study population consisted of 35 patients with CIDP confirmed by NCS and 30 patients with genetically proven CMT1 by PMP 22 Gene analysis and PFGE-Southern Blot. In order to differential diagnosis in acquired and congenital demyelinating neuropathies, I analyzed the frequency of abnormalities in sensory nerve conduction studies of meidan, ulnar, and sural nerve. CMT 1 was more severe sensory polyneuropathy better than CIDP in sensory NCS. The main finding of the present work was the pattern of nerve conduction abnormalities differs between these disorders. Recognition of these elctrophysiological patterns may be helpful for differential diagnosis of CMT 1 and CDIP.

오르막보행 시 타이거스텝 하지 움직임에 미치는 영향

강지혁,윤석훈 한국운동역학회 2022 한국운동역학회지 Vol.32 No.1

Objective: The aim of this study was to investigate the effect Tiger-step walking on the movement of the lower extremities during walking. Method: Twenty healthy male adults who had no experience of musculoskeletal injuries on lower extremities in the last six months (age: 26.85 ± 3.28 yrs, height: 174.6 ± 3.72 cm, weight: 73.65 ± 7.48 kg) participated in this study. In this study, 7-segments whole-body model (pelvis, both side of thigh, shank and foot) was used and 29 reflective markers and cluster were attached to the body to identify the segments during the gait. A 3-dimensional motion analysis with 8 infrared cameras and 7 channeled EMG was performed to find the effect of tigerstep on uphill walking. To verify the tigerstep effect, a one-way ANOVA with a repeated measure was used and the statistical significance level was set at α=.05. Results: Firstly, Both Tiger-steps showed a significant increase in stance time and stride length compared with normal walking (p<.05), while both Tiger-steps shown significantly reduced cadence compared to normal walking (p<.05). Secondly, both Tiger-steps revealed significantly increased in hip and ankle joint range of motion compared with normal walking at all planes (p<.05). On the other hand, both Tiger-steps showed significantly increased knee joint range of motion compared with normal walking at the frontal and transverse planes (p<.05). Lastly, Gluteus maximus, biceps femoris, medial gastrocnemius, tibialis anterior of both tiger-step revealed significantly increased muscle activation compared with normal walking in gait cycle and stance phase (p<.05). On the other hand, in swing phase, the muscle activity of the vastus medialis, biceps femoris, tibialis anterior of both tiger-step significantly increased compared with those of normal walking (p <.05). Conclusion: As a result of this study, Tiger step revealed increased in 3d range of motion of lower extremity joints as well as the muscle activities associated with range of motion. These findings were evaluated as an increase in stride length, which is essential for efficient walking. Therefore, the finding of this study prove the effectiveness of the tiger step when walking uphill, and it is thought that it will help develop a more efficient tiger step in the future, which has not been scientifically proven.

후각자극에 의한 대뇌겉질의 전기생리학적 반응에 대한 연구: 알파 활동도

강지혁 대한임상검사과학회 2019 대한임상검사과학회지(KJCLS) Vol.51 No.4

Many studies in recent decades have revealed that olfactory stimulation by perfume or malodor inhalation exerts various psychological and physiological effects on humans. The most recent studies have examined the electrophysiological response of olfactory stimulation on the activity of human cortical nerve cells. The purpose of this current study is to quantitatively analyze what changes occur in the alpha activity in healthy participants (N=12) on olfactory stimulation using two types of odors (acacia and butanol). Exposure to the odor of acacia perfume was associated with a significant increase (66.7%) in alpha activity when compared with that of the no-odor background EEG. Exposure to the odor of butanol was associated with a significant reduction (33.3% to 41.7%) in EEG alpha activity when compared with that of the no-odor control. The results of this study demonstrated the potential to alter the cerebral cortex activity by olfactory stimulation. The results also suggest that olfactory perception has stimulatory effects on the function of the nervous system. In other words, it could be concluded from this study that inhalation of olfactory stimulation affected brain wave activities and mood states. Further research is needed to completely understand and describe the electrophysiological effects of different odors on the central nervous system. 최근 수십 년 동안 향기 및 악취 흡입에 의한 후각자극이 인간에게 심리적, 생리적 영향을 미친다는 다양한 연구가 보고되고있다. 본 연구는 후각자극에 의한 사람 대뇌겉질 신경세포의 전기생리학적 반응성을 조사하고자 하였다. 건강한 남성 12명을대상으로 아카시아와 부탄올에 의한 후각자극이 알파파의 활동도에 미치는 영향을 정량적으로 분석하였다. 아카시아 향취를흡입하는 경우는 후각자극이 없는 안정상태의 뇌파에 비해 알파파의 활동도가 유의하게 증가(66.7%)하였고, 부탄올 악취에서는 알파파 활동도의 유의한 감소(33.3%∼41.7%)가 관찰되었다. 본 연구는 후각자극에 의하여 대뇌겉질 신경세포의 활동도에 변화가 있을 수 있다는 것을 시사한다. 이러한 결과는 후각인지가 신경계의 기능에 자극효과를 나타낼 수 있다는 것을 의미한다. 즉 본 연구에서 후각자극이 뇌파활동과 기분상태에 영향을 미친다는 결론을 도출할 수 있었다. 이러한 관점에서 향후 중추신경계에 대한 전기생리학적 효과의 영향을 이해하고, 설명하기 위한 추가연구가 필요할 것으로 사료된다.

근위축성측삭경화증의 전기생리학적 특징 : 신경전도검사

강지혁(Kang Ji-Hyuk),이윤섭(Lee Yun-Seob) 한국체육과학회 2009 한국체육과학회지 Vol.18 No.3

OBJECTIVES: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder, characterized by a selective progressive degeneration of the motor system. Electromyography is essential for the diagnosis of ALS. The measurement of motor conduction of peripheral nerves is of major importance to recognize other possible causes of progressive muscle wasting. Never conduction study (NCS) is an objective, quantitative, and reproducible measure of peripheral nervous function and has been widely used for the differential diagnosis of nervous disease. METHODS: In this study we analyze the values of motor nerve conduction studies and sensory nerve conduction studies were performed; distal motor latency (DML), compound muscle action potential (CMAP), motor nerve conduction velocity (MNCV), compound nerve action potential and sensory nerve conduction velocity in 82 patients with definite ALS. RESULTS: We found slight slowing of SNCV and moderate to strong reduction of CMAP, MNCV and a prolongation of DML. We found no significant change No potential and conduction block between ALS and control. CONCLUSIONS: The main finding of the present work was moderate to strong reduction of motor nerve and slight sensory involvement in ALS. And NCS do not seem to be a sole measure to the end because they sometimes showed undistinguishable results. Accordingly, more researches on electrophysiology characteristics of NCS in ALS should be carried out for its precise clinical application in the future.

역세권 주변 부지를 활용한 경기도 공공 임대주택 제안

강지혁(Kang, Ji-Hyeok),장지혁(Jang, Ji-Hyuk),조용훈(Cho, Yong-Hoon) 한국주거학회 2017 한국주거학회 학술대회논문집 Vol.29 No.2

CIDP와 CMT 1형의 전기생리학적 특성에 대한 정량 분석 : 감각신경연구

강지혁 ( Ji-hyuk Kang ) 대한임상검사과학회 2021 대한임상검사과학회지(KJCLS) Vol.53 No.2

선천성 유전질환인 CMT와 후천성 면역 매개 질환인 CIDP는 임상적 증상이 유사하므로 두 질환의 감별진단을 위해서는 말초신경의 전기생리학적 특징을 비교하는 것이 도움이 될 수 있다. 본 연구는 CIDP와 CMT 1형으로 확진된 환자의 신경전도검사 결과 중 감각신경전도검사의 주요 지표별 결과를 후향적으로 정량분석하여 두 질환군의 전기생리학적 특징을 규명하고자 하였다. CIDP (N=35)와 CMT1 (N=30)로 확진된 환자의 dCNAP와 SNCV를 이용하여 두 질환군의 중증도 분석, 유의성 검정, 비정상 범위별 비율분석 및 상관분석을 실시하여 통계적 차이를 기반으로 특징을 비교하였다. 두 질환 모두 전신성 말초신경다발신경병증의 특징이 관찰되었고, 장딴지신경의 손상이 가장 심한 것으로 확인되었다. CMT1군은 탈수초성 및 축삭성 신경병증을 동반하는 전신성 신경병증이고, CIDP보다 더 중증의 신경병증임이 확인되었다. 또한, 상관계수 및 산점도 분석에서 CMT1은 신경 손상 범위가 전체 신경에서 균등한 전기생리학적 특징이 관찰되었다. 감각신경전도검사의 결과를 기반으로 한 본 연구결과가 CIDP와 CMT 1형의 감별진단 및 연구에 도움이 될 것으로 사료된다. Charcot-Marie-Tooth disease (CMT) is a slowly progressive hereditary degenerative disease and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired immune-mediated disorder characterized by weakness and sensory deficits. The purpose of this study was to analyze and compare the electrophysiological characteristics observed in sensory nerve conduction studies (SNCS) of both diseases. A retrospective study of 65 patients with a diagnosis of CIDP (N=35) and CMT type I (N=30) was performed. This study analyzed No potentials ratio, distal compound nerve action potential (dCNAP) of various nerve types, and a correlation coefficient analysis of the sensory nerve conduction velocity (SNCV). As a result, I found that CMT 1 was more severe systemic demyelinating and axonal polyneuropathy better than CIDP (P<0.05). In a quantitative analysis of dCNAP and SNCV, especially sural nerve was the most severe nerve injury observed in both diseases. In correlation and scatter plot analysis, CMT 1 showed relatively high correlations compared to CIDP based on the correlation coefficient analysis (Fisher’s Z test) of SNCV. The results of this study suggested that CMT 1 showed the slowness in SNCV, one of the characteristics of demyelinating polyneuropathy, and this slowing had a uniform pattern. In conclusion, electrophysiological characteristic of SNCS may be useful in the diagnosis and research between patients with CMT 1 and CIDP. Copyright Ⓒ 2021 The Korean Society for Clinical Laboratory Science. All rights reserved.

원통 좌표계에서 퍼지 제어기를 이용한 매니퓰레이터의 영상기반 비주얼 서보잉

강지혁(Jihyeok Kang),좌동경(Dongkyoung Chwa) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.7