등속성 근력 측정기를 이용한슬관절 우력 곡선의 분석

이시욱,한태륜,방문석 大韓再活醫學會 2000 Annals of Rehabilitation Medicine Vol.24 No.5

사체 슬관절 연골에서 자기 공명 영상조영제 흡수를 이용한 Glycosaminoglycan의 정량적 분석

이시욱,Lang, Philipp,한태륜 대한슬관절학회 2003 대한슬관절학회지 Vol.15 No.1

목적 : 조영제를 이용한 자기 공명 영상의 T1 이완 시간과 glycosaminoglycans(GAG) 농도와의 상관관계를 밝혀 골관절염의 조기 진단에 유용한 지 알아보았다. 대상 및 방법 : 8개의 사체 슬관절 부위에서 조영제 투여전 자기 공명 영상에서 T1 이완시간을 얻었다. 조영제(GdDTPA², 4mM/L)를 포함한 생리 식염수 40㎖를 관절내 주사하고 7시간후에 자기 공명 영상을 촬영하였다. 대퇴골과 경골의 내과 및 외과의 14부위에서 연골을 채취하고, 습중량, 건중량, GAG 성분, DNA 성분을 측정하였다. T1 자기 공명 영상으로부터 T1 지도를 만들고 각 연골 조각에 해당하는 부분의 T1 이완 시간을 계산헤 내어 이를 생화학 분석 결과와 비교하였다. 결과 : 조영제 투여 전과 후에 얻은 T1 이완 시간으로부터 계산한 조영제의 농도는 GAG의 농도와 역상관 관계를 보였다. 결정 계수(R²)는 0.684이었다. 대퇴 내과, 대퇴내과, 경골 내과, 경골 외과의 R²값은 각각 0.754, 0.639, 0.788, 0.644 이었다. 결론 : 조영제를 이용하여 얻은 자기 공명 영상의 T1이완 시간이 연골내 GAG 농도와 유의한 상관 관계를 보여 이를 골관절염의 조기 진단에 이용할 수 있을 것으로 생각된다. Purpose: To determine the vlaidity of the gadolinium(GdDTPA²_(-)) enhanced magnetic resonance(MR) images by correlating to biochemical components especially glycosaminoglycans(GAG) content in the early detection of osteoarthritis. Materials & Materials : Eight cadaveric knee was scanned to obtaine pre-contrast T1 relaxation time using a 1.5T MR imaging unit. 7 hours after intra-articular injectionof 40㎖ of saline solution containing 4mM/L GdDTPA²_(-), MR images were obtained. Cartilges of the knee segments were removed from 14 sites of medial and lateral condyles of femur and tibia. Wet weight, dry weight, GAG content, and DNA content were measured. From the T1-weighted image series, T1 maps were generated. The T1 relaxation times of each part of the cartilage were compared with the results of the biochemical assay. Result : The concentration of GdDTPA²_(-) calculated from pre- and post-contrast T1 relaxation times was reverse-linearly related to GAG concentration. The R²(squre of correlation coefficient) was 0.684. The R² for medial femoral condyle, lateral femoral condyle, medial tibial condly, and lateral tibial condyle were 0.754, 0.639, 0.788, and 0.644, respectively. Conclusion : GdDTPA²_(-)enhanced MR imaging can be used as a method of GAG imaging which has a potential for the early diagnosis of osteoarthritis.

Postoperative delirium after hip surgery is a potential risk factor for incident dementia: A systematic review and meta-analysis of prospective studies

Lee, Soong Joon,Jung, Se Hee,Lee, Shi-Uk,Lim, Jae-Young,Yoon, Kang-Sup,Lee, Sang Yoon Elsevier Ireland 2020 Archives of Gerontology and Geriatrics Vol.87 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Although a few trials have explored the relationship between postoperative delirium (POD) and incident dementia in patients with hip surgery, the numbers of participants in each study are relatively small. Thus, we performed a meta-analysis to examine whether POD after hip surgery is a risk factor for incident dementia.</P> <P><B>Methods</B></P> <P>Six prospective cohort studies investigating the development of incident dementia in patients with POD after hip surgery were retrieved from PubMed, Embase, and the Cochrane Library. We performed a pairwise meta-analysis using fixed- and random- effect models.</P> <P><B>Results</B></P> <P>POD significantly increased the risk of incident dementia and cognitive decline (overall odds ratio [ORs] = 8.957; 95 % confidence interval [CI], 5.444–14.737; <I>P</I> < 0.001 in fixed-effects model; overall ORs = 8.962; 95 % CI, 5.344–15.029; P < 0.001 in random-effects model). A publication bias was not evident in this study.</P> <P><B>Conclusions</B></P> <P>Our meta-analysis revealed that POD after hip surgery is a risk factor for incident dementia. Early identification of cognitive function should be needed after surgery and appropriate prevention and treatment for dementia will be required, especially in cases with POD.</P> <P><B>Highlights</B></P> <P> <UL> <LI> No meta-analysis has assessed the relationship between postoperative delirium and incident dementia after hip surgery. </LI> <LI> Our meta-analysis revealed that postoperative delirium after hip surgery is a risk factor for incident dementia. </LI> <LI> Early identification of cognitive function should be needed after surgery, especially in cases with postoperative delirium. </LI> </UL> </P>

Mild to Moderate Early Exercise Promotes Recovery from Cerebral Ischemia in Rats

Lee, Shi-Uk,Kim, Dae-Yul,Park, Sung-Hye,Choi, Deok-Hyung,Park, Hee-Won,Han, Tai Ryoon Cambridge University Press 2009 The Canadian journal of neurological sciences Vol.36 No.4

<B>Objective:</B><P>We examined the effects of various exercise intensities on recovery from middle cerebral artery occlusion (MCAO) in rats.</P><B>Methods:</B><P>First, we administered a 120-minute left MCAO to male Sprague-Dawley rats and randomly assigned them to one of four groups: no exercise (Group 1), mild exercise (Group 2), moderate exercise (Group 3), and severe exercise (Group 4). Then, we trained the rats for 30 min per day for one week or two weeks. We used a five-point neurological evaluation scale to measure neurological deficits 1-day, 4-days, 7-days, 10-days and 14-days after MCAO and measured infarct volume by use of 2% 2,3,4-triphenyltetrazolium chloride in exercised brains. We also performed immunohistochemistry analysis of the brain to observe reactive astrocytosis at the peri-infarct region.</P><B>Results:</B><P>Neurological examination indicated that Group 2 and 3 recovered better than Group 1 after one week and two weeks (p<0.05). Moreover, Group 2 and 3 had reduced brain infarct volume compared with Group 1 after one week (p<0.05). There were no significant differences between Group 4 and Group 1. The thickness of the peri-infarct astrocytosis was significantly reduced in Group 4 relative to Group 1 after one week. There was a significant negative correlation between the extent of reactive astrocytosis and neurological recovery (r= -0.648, p<0.01).</P><B>Conclusion:</B><P>This study demonstrates that mild to moderate exercise that begins soon after induced cerebral ischemia promotes recovery and that astrocytes may have an important role in the recovery process.</P>

Clinical Outcomes of Conservative Treatment and Arthroscopic Repair of Rotator Cuff Tears: A Retrospective Observational Study

Woo Hyung Lee,Hyun Kyung Do, Joong Hoon Lee,Bo Ram Kim,Jee Hyun Noh,Soo Hyun Choi,Sun Gun Chung,Shi-Uk Lee,최지은,Seihee Kim,Min Jee Kim,Jae-Young Lim 대한재활의학회 2016 Annals of Rehabilitation Medicine Vol.40 No.2

Objective To compare the clinical outcomes following conservative treatment and arthroscopic repair in patients with a rotator cuff tear.Methods In this retrospective study, patients aged >50 years with a symptomatic rotator cuff tear were reviewed. The rotator cuff tendons were evaluated using ultrasonography, shoulder magnetic resonance imaging or MR arthrography, and the patients with either a high-grade partial-thickness or small-to-medium-sized (≤3 cm) full-thickness tear were included in this study. The primary outcome measures were a pain assessment score and range of motion (ROM) at 1-year follow-up. The secondary outcomes were the rate of tear progression or retear along with the rate of symptom aggravation after the treatments.Results A total of 357 patients were enrolled, including 183 patients that received conservative treatment and 174 patients who received an arthroscopic repair. The pain assessment score (p<0.001) and the ROM in forward flexion (p<0.001) were significantly improved in both groups. The ROM in internal rotation did not significantly change after conservative treatment and arthroscopic repair. The pain assessment score and ROM were not significantly different between the two groups. Retear was observed in 9.6% of patients who had an arthroscopic repair and tear progression was found in 6.7% of those who underwent conservative treatment. The proportion of aggravation for pain and ROM did not significantly differ between the two groups.Conclusion The effectiveness of conservative treatment is not inferior to arthroscopic repair for patients >50 years old with a less than medium-sized rotator cuff tear in a 1-year follow-up period. Further study is warranted to find the optimal combination of conservative treatment for a symptomatic rotator cuff tear.

Reference Standards for Nerve Conduction Studies of Individual Nerves of Lower Extremity With Expanded Uncertainty in Healthy Korean Adults

Jae Yoon Kim,김은경,Hyung Seok Shim,Jae Hyun Lee,Goo Joo Lee,Keewon Kim,Jae-Young Lim,Jaewon Beom,Sang Yoon Lee,Shi-Uk Lee,Sun Gun Chung,Byung-Mo Oh 대한재활의학회 2022 Annals of Rehabilitation Medicine Vol.46 No.1

Objective To develop a set of reference standards for tibial motor, common peroneal motor, sural sensory, and superficial peroneal sensory nerve conduction studies (NCSs) with expanded uncertainty in a healthy Korean population.Methods Standardized procedures were conducted for individual lower extremity NCSs of 199 healthy participants in their 20s (n=100) and 50s (n=99). Mean values and expanded uncertainties for parameters were analyzed with thorough consideration of multiple uncertainty factors under the International Guide to the Expression of Uncertainty in Measurement. In addition, side-to-side differences in onset latency, amplitude, and nerve conduction velocity (NCV) were analyzed.Results Mean (reference range) for distal onset latency, baseline to negative peak amplitude, NCV of tibial motor nerve in males in their 20s were 4.3 ms (3.1–5.4 ms), 7.1 mV (3.4–10.9 mV), and 50.7 m/s (42.2–59.3 m/s), respectively; sural sensory nerve baseline to negative peak amplitude in males in their 20s was 21.7 μV (8.3–35.2 μV). Including the aforementioned data, we present a vast dataset of normative mean values and expanded uncertainties for NCSs of the leg in a healthy Korean population. Furthermore, upper limits for normal side-to-side differences for onset latency, amplitude, and NCV of each nerve are suggested.Conclusion To our knowledge, this is the first study to present the reference standards of leg NCSs with consideration for multifactorial uncertainties in an Asian population. We expect these results to help practitioners make reliable and reproducible clinical decisions.

Force Ripple and Magnetic Unbalance Reduction Design for Doubly Salient Permanent Magnet Linear Synchronous Motor

Shi-Uk Chung,Ji-Won Kim,Byung-Chul Woo,Do-Kwan Hong,Ji-Young Lee,Dae-Hyun Koo IEEE 2011 IEEE transactions on magnetics Vol.47 No.10

<P>Permanent magnet linear synchronous motor (PMLSM) has been successfully applied in various industry fields due mainly to excellent dynamic characteristics and accurate positioning capability. However, PMLSM suffers force ripple, which deteriorates controllability, and it is often considered to be an expensive linear drive mechanism since it requires a large amount of rare-earth permanent magnet (PM) material in the stationary part. This paper introduces and analyzes a new design of winding and mover arrangement for doubly salient permanent magnet linear synchronous motor (DSPMLSM). The proposed design reduces force ripples, magnetic unbalance, and the amount of PM material used in the stationary part. Extensive finite element analysis (FEA) reveals the effectiveness of the proposed design.</P>

A Novel Design of Modular Three-Phase Permanent Magnet Vernier Machine With Consequent Pole Rotor

Shi-Uk Chung,Ji-Won Kim,Byung-Chul Woo,Do-Kwan Hong,Ji-Young Lee,Dae-Hyun Koo IEEE 2011 IEEE transactions on magnetics Vol.47 No.10

<P>The permanent magnet vernier machine (PMVM) is known to be well suited for direct drive applications due to its high torque characteristics at low speed. This paper introduces a novel design of PMVM comprising a modular stator and a consequent pole rotor. The proposed design magnetically decouples each phase and suppresses the magnetic unbalance caused by the consequent pole rotor.</P>

Design Considerations and Validation of Permanent Magnet Vernier Machine with Consequent Pole Rotor for Low Speed Servo Applications

Shi-Uk Chung,Yon-Do Chun,Byung-Chul Woo,Do-Kwan Hong,Ji-Young Lee 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.5

This paper deals with design consideration and validation of a new pole-slot combination for permanent magnet vernier machine (PMVM) with consequent pole (CP) rotor especially for extremely low speed servo applications. A 136pole-24slot PMVM with CP rotor is introduced and analyzed by 2D and 3D finite element analysis (FEA) and discussion on experimental validation is also included.

Design Considerations and Validation of Permanent Magnet Vernier Machine with Consequent Pole Rotor for Low Speed Servo Applications

Chung, Shi-Uk,Chun, Yon-Do,Woo, Byung-Chul,Hong, Do-Kwan,Lee, Ji-Young The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.5

This paper deals with design consideration and validation of a new pole-slot combination for permanent magnet vernier machine (PMVM) with consequent pole (CP) rotor especially for extremely low speed servo applications. A 136pole-24slot PMVM with CP rotor is introduced and analyzed by 2D and 3D finite element analysis (FEA) and discussion on experimental validation is also included.