• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.832-839
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• 2007

In this study, a new bicycle system was developed to improve muscular strength using the Magneto-Rheological(MR) rotary brake. The friction load of the MR rotary brake is adjusted according to muscle strength of the subjects. The characteristic of muscular strength was studied with various friction loads of MR rotary brake. The friction load was occurred with the current, applied to the MR. rotary brake. Experiments was composed of several cycling trials for various friction loads. In training programs involving muscle improvement, it is necessary to confirm muscle activity and fatigue. To measure the muscle activity and fatigue, EMG signals of rectus femoris (RF), biceps femoris (BF), tensor fasciae latae (TFL), vastus lateralis (VL), vastus medialis (VAS), gastrocnemius (GAS), tibialis anterior (TA) and soleus (SOL) muscles were collected with surface electromyography and analyzed into time and frequency domain. The experimental results showed that the muscle activity according to the applied current to the MR rotary brake was significantly different. The more the current was applied, the higher value of the integrated EMG (IEMG) was obtained. Especially, the magnitude of IEMG of the RF, BF, TFL and VL varied in direct proportion to the current. However, there was not significant in the median frequency as the cycling time continue.

• Imaging Science in Dentistry
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• 제45권1호
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• pp.1-5
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• 2015

Purpose: Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Materials and Methods: Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher's exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Results: Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. Conclusion: In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

• 대한의용생체공학회:의공학회지
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• 제30권4호
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• pp.333-340
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• 2009

MR compatible coaxial-slot antenna for microwave hyperthermia was developed while its structure and size of each part were determined by computer simulation using finite element method(FEM). Its local heating performance was evaluated using tissue-mimic phantom and swine muscles. 2% agarose gel mixed with 6mM/$\ell$ $MnCl_2$ as a biological tissue-mimic phantom was heated by the proposed antenna driven by a 2.45GHz microwave generator. The temperature changes of the phantom were monitored using multi-channel digital thermometer at the distance of 0mm, 5mm, 10mm and 20mm from the tip center of the antenna. Also muscle tissue of swine was heated for 2 and 5minutes with 50W and 30W of microwave generator powers, respectively, to evaluate the local heating performance of the antenna. MRI compatibility was also verified by acquiring MR images and MR temperature map. MR signals were acquired from the agarose gel phantom using $T2^*$ GRE sequence with 1.5T clinical MRI scanner(Signa Echospeed, GE, Milwaukee, WI, U.S.A.) at Pusan Paik Hospital and were transferred to PC in order to reconstruct MR images and temperature map using proton resonance frequency(PRF) method and laboratory-developed phase unwrapping algorithm. Authors found that it has no severe distortion due to the antenna inserted into the phantom. Finally, we can conclude that the suggested coaxial-slot antenna has an excellent local heating performance for both of tissue-mimic phantom and swine muscle, and it is compatible to 1.5T MRI scanner.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 1996년도 추계학술대회 초록집
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• pp.26-26
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• 1996

• 한국동물학회지
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• 제29권3호
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• pp.190-200
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• 1986

논우렁이의 組織別 蛋白質 패턴에 있어서 筋肉은 雌雄에 關係없이 16個의 主要蛋白質 bands는 거의 同一하였으며, 그 중에서 bands E (Mr. 41,500), H (Mr. 52,100), L (Mr. 71,700), N(Mr. 98,500), O (Mr. 107,900) 와 P (Mr. 112,900)는 筋肉과 精巢 卵巢에서 나타나는 蛋白質이었다. 그러나 精巢나 卵巢의 蛋白質 패턴은 그들 固有의 蛋白質 패턴을 가지고 있었으며 組織에서 全部 나타나는 band外에 精巢와 卵巢에서 共同으로 나타나는 主要한 bands는 약 5個[bands d (Mr. 15,600), k (Mr. 37,100), p (Mr. 57,000), s (Mr. 80,300), v (Mr. 105,400)]로 나타남을 알 수 있었다. 그리고 主要蛋白質 bands를 elution 시켜서 아미노산을 分析한 結果는 단백질 패턴의 양상과 같이, 아미노산의 量과 組成이 많은 순서는 卵巢, 筋肉, 精巢의 順으로 되었다. 이러한 結果를 볼 때 卵巢에서는 全個體에서 가질수 있는 豊富한 蛋白質이 發見되는 同時에 精巢에서는 核酸物質의 濃縮으로 情蟲이 되기 위한 morphogenesis의 現象으로 말미 암아 蛋白質의 量이 매우 적게 나타나는 것으로 生覺되었다.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.167-167
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• 2001

Purpose： To obtain normative human skeletal muscle data and evaluate quantitative diffusion-ten anisotropy information using diffusion-tensor imaging technique. Method： Quantitative extremity muscle diffusion tensor MR images were obtained in 5 healt adults by using turbo STEAM sequence and a combination of tetrahedral and orthogon diffusion gradients. Relative anisotropy(RA) and fractional anisotropy(FA) values we measured in soleus and gastrocnemius muscle in addition to mean ADC value.

• 제어로봇시스템학회논문지
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• 제16권6호
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• pp.579-585
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• 2010

In this paper, an assistive device for a knee joint to help a disabled person to stand up by supporting power is presented. The device is designed and controlled by using damping characteristics of the MR (Magneto-Rheological) damper. The MR damper helps the person to sit slowly and safely. A DC motor supports muscle power in the case of standing motion. Thus the device helps the disabled person to sit down and stand up. Through the experiments, it is feasible that an assistive device can help the disabled person to standup according to the foot pressure change.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 춘계학술대회
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• pp.28-30
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• 1993

We have investigated the feasibility study, especially for optimal TR, to obtain 3-D MR neurographic imaging (neurograms or nervography) which shows the distribution of peripheral nerve fibers at the human forearm using 4.7 T magnet. To peform a successful formation of MR neurographic imaging, nerve signal should be separated from the other signal comes from surrounding muscle or fat, because nerves are usually embeded in muscle or fat. Generally, it is well known that nerve has shoter T1 value than that of muscle. Thus, repetition time was optimized to maximize the signal intensity defference between the muscel and nerve. We have also used spin-echo(SE) sequence with long echo time($60{\sim}90\;msec$) to enhance the different signal intensity between muscles and pheriperal nerves base on the fact that muscle tissue has longer T2 relaxation lime than that or nerve.

• Investigative Magnetic Resonance Imaging
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• 제13권1호
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• pp.101-105
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• 2009

저자들은 육종의 일종으로 분류되는 유방의 악성 엽상종양이 골격근으로 전이된, 현재까지 영상소견으로는 보고된 사례가 없는, 드문 증례의 초음파, 양전자방출 단층촬영, 전산화 단층 촬영, 자기공명영상 소견을 보고하고자 한다.

• Journal of Chest Surgery
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• 제39권7호
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• pp.549-552
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• 2006

심각한 허혈성 심근병증(ischernic cardiomyopathy, ICMP)에 동반된 승모판 폐쇄부전증에 있어서 심장이식이 여의치 않은 상황에서의 수술적 치료로는 경색이 아닌 부위의 심근(viable myocardium)에 대한 관상동맥 우회술(coronary revascularization)과 좌심실 용적 축소술(LV reduction), 승모판 재건술(mitral reconstruction)이 그 중심으로 자리잡고 있다. 허혈성 심근병증에 있어서 승모판 폐쇄 부전은 다양한 병인으로 나타나며, 그 중 판막륜의확장 외에도 유두근의 전위가 중요한 원인으로 지적되고 있다. 본원에서는 승모판 폐쇄 부전증을 동반한 좌 주 관상동맥을 포함한 심한 관상동맥질환과 허혈성 심근병증 환자에 대한 관상동맥 우회술과 함께, 좌심실 절개를 통한 승모판 뒤판엽 성형술(posterior mitral annuloplasty), 유두근 단축술(Papillary muscle plication)의 수술적 치험을 보고하고자 한다.