• 대한인간공학회지
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• 제15권2호
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• pp.177-184
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• 1996

In light-weight hand tools, static posture may result in postural fatigue. Psotural tremor of the upper extremity in a static posture was measured to provide guidelines for hand tool weight. Postural tremor was measured on five levels of tool weitht : no weight, 400g, 800g, 1200g, and 1600g. Three types of camcorder recording postures were selected. For each condition, postural tremor was measured together with ENG of biceps, deltoid and pectoralis major, and Borg's CR-20 ratings of perceved exertion. Results of the experiment are as follows : frequency analysis of tremor revealed increased amplitude of frequency bands of 2-4Hz and 10-14Hz. Postural tremor of the upper extremeity maintained the initial level until fatigue developed. After the development of fatigue, the rate of change of postural tremor significantly increased. Different tool weights and hand postures showed different rates of tremor increase. Time tp fatigue and corresaponding endurance time were positively correlated with Borg's RPE scores.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.151-157
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• 1996

Postural tremor of the upper arm in a static posture was measured to provide guidelines of hand tool weight. Three types of camera recording postures were selected. Postural tremor was measured on five levels of tool weights; no weight, 400g, 800, 1200g, and 1600g. For each conditions, upper arm postural tremor was measured together with EMG of biceps, deltoid, and pectoralis major, and Borg's CR-20 scale ratings of perceived exertion. Results of the experiment are as follows; Frequency analysis of tremor revealed that increased amplitude of frequency band of 2-4Hz and 10-14Hz was observed. Postural tremor of the upper arm maintained the initial level until fatigue developed. After the development of fatigue, the rate of the change of postural tremor was significantly increased. Different tool weights and hand postures showed different rate of tremor increase. And time to fatigue and the corresponding endurance time was positively correlated with Borg's RPF scores.

• 대한의용생체공학회:의공학회지
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• 제37권1호
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• pp.15-20
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• 2016

Essential tremor is a neurological disorder with a tremor of the arms and hands. It is well known that essential tremor is characterized by the postural tremor and the action tremor. There has been no report on the quantitative difference in the characteristics of two tremor types. The purpose of this study was to investigate the possible difference in tremor characteristics of postural and action tremors. Seventeen patients with essential tremor ($68.9{\pm}7.9years$, 7 men, 10 women) participated in this study. Patients performed the tasks of postural maintenance (arms outstretched) and daily actions (spiral drawing). Three-axes (pitch, roll and yaw) gyro sensors were attached on index finger, back of hand and forearm, from which the segment and the joint angular velocities were calculated. Outcome measure was the tremor amplitude defined as the root-mean-square mean of the vector-sum angular velocity at segments and joints. Two-way ANOVA showed that task and joint had main factor on the tremor amplitude (p < 0.05). Post-hoc analysis revealed that tremor amplitude at the metacarpo-phalangeal joint was not affected by task (p > 0.05). However, tremor amplitude at the wrist joint differed among the tasks (p < 0.05), and it was greater in the action tasks than in postural task. Tremor was greater at finger segments than at hand and forearm and it increased in action tasks. The results of this study would be helpful for the understanding and task-specific treatments of the essential tremor.

• 대한의용생체공학회:의공학회지
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• 제36권4호
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• pp.103-108
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• 2015

Discrimination of Parkinson's disease (PD) from Essential tremor (ET) is often misdiagnosed in clinical practice. Since tremor is time-varying signal, and dominant and harmonic frequencies are shown in tremor only with moderate or severe symptom, there are some limitations to use frequency related features. Moreover, patients with PD or ET can suffer from both resting tremor and postural tremor. In this study, 28 patients with PD and 17 patients with ET were enrolled. Tremor was measured with accelerations on the more affected hand during resting and postural conditions. The ratio of root mean square (RMS) of resting tremor to RMS of postural tremor, the mean coefficients of autocorrelation function (ACF), and the mean of differences of two adjacent coefficients of ACF at resting and postural were calculated and compared between PD and ET. The performance showed 98% accuracy with support vector machine and leave-one-out cross validation. In addition, the method accurately differentiated the patients with tremor-dominant PD from patients with ET, with 100% accuracy. Therefore, the developed algorithm can assist clinicians in diagnosing and categorizing patients with tremor, especially, patients with mild symptom or the early stage of a disease, for proper treatment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.1189-1190
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• 2012

• Annals of Clinical Neurophysiology
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• 제11권1호
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• pp.9-15
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• 2009

Background: To investigate the differences of locomotor dynamics between Parkinson's disease (PD) patients with tremor dominant symptom and patients with postural instability dominant symptom. Methods: 66 subjects with PD were classified into two subgroups, tremor-dominant group and postural instability and gait disorder group by Unified Parkinson's disease rating scale (UPDRS). The spatial, temporal and electrodynamic gait parameters were recorded automatically using computerized 3-D motion analysis system with electrogoniometer. Results: There was no significant difference in cadence, pelvic tilt range, hip flexion range, knee flexion range and ankle dorsiflexion range. Postural instability and gait disorder group showed decreased gait velocity, short stride length, decreased range of motion in pelvic obliquity, pelvic rotation and ankle plantar flexion. Conclusions: There was meaningful difference in locomotor dynamics between Parkinson's disease(PD) patients with tremor dominant symptom and patients with postural instability dominant symptom.

• 대한의용생체공학회:의공학회지
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• 제35권4호
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• pp.81-86
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• 2014

One of the methods for Parkinson's disease(PD) tremor evaluation is the Clinical Tremor Rating Scale(CTRS). However, the method has some limitations that clinician ratings can vary because the scores are subjectively rated. In addition, most researches usually collected data measured on the more affected arm. In this study, we developed a portable wearable system(SNUMAP system) for measuring PD tremor. The SNUMAP system captures 3-dimensional motion using tri-accelerometer and tri-gyroscope on finger and wrist. 40 PD patients participated in resting tremor and postural tremor tasks, while wearing the system on both hands simultaneously. Estimated tremor scores from Leave-One-Out Cross Validation for regression were highly correlated to the average clinician CTRS scores for rest tremor($r^2$ = 0.87, RMSE = 0.48) and postural tremor($r^2$ = 0.82, RMSE = 0.48). Therefore, the quantitative assessment model can improve treatment of PD patients.

• 대한한방내과학회지
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• 제27권3호
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• pp.776-783
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• 2006

Tremor is a rhythmic and involuntary muscular contraction characterized by oscillations of a part of the body. The most common of all involuntary movements, tremor can affect various body parts such as hands, head, facial structures, vocal cords, trunk, and legs; most tremors, however, occur in the hands. Clinically, tremor is classified into postural tremor, resting tremor, action tremor, and other kinds of tremor, and treated according to the causes. The author reports the improvement of the patient, hospitalized at Dong Seo Medical Center, whose tremor was not classified specifically in western medicine but was diagnosed as Ganhyeolbujok (肝血不足) by Korean medicine.

• 한국융합학회논문지
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• 제12권7호
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• pp.263-271
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• 2021

거총부터 격발까지 총구 움직임의 궤적을 추적하여, 사격의 정확성을 향상시킬 목적으로 광전자 기반 사격 훈련 시스템이 사격 훈련 현장에서 활용되어 왔다. 광전자 기반 시스템은 설치가 복잡하고, 표적의 파손 위험이 존재하며, 고가의 장비로 선수들의 접근성이 떨어진다는 단점이 있다. 이에 본 연구는 저비용의 가속도 센서 모듈을 이용하여 체위 떨림을 측정하고 피드백할 수 있는 사격 훈련 시스템을 개발하고, 이의 활용성을 검증하였다. 가속도 센서 모듈은 총기의 에어 실린더에 부착할 수 있도록 제작되었다. 체위 떨림은 가속도 센서 데이터를 이용하여 진폭, 주파수, 공간적 패턴 지표로서 분석되었다. 가속도 센서와 기존의 광전자 기반 시스템에서 측정된 사격시 체위 떨림 진폭 지표 간에는 높은 상관관계(좌우 방향: r=0.76; 상하 방향: r=0.70)가 나타났다. 또한, 사격 선수를 대상으로 진행한 시스템의 유효성 평가에서는 선수의 사격 점수(최상, 최하 격발)에 따라 계산된 체위 떨림 지표가 유의한 차이(p<0.05)가 있음을 독립 표본 t-검증을 이용하여 검증하였다.

• 대한한방내과학회지
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• 제38권6호
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• pp.1096-1100
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• 2017

The carotid artery is one of the main vessels supplying blood to the brain. Carotid artery stenosis is mostly caused by atherosclerosis, a disease where cholesterol is deposited in the arterial blood vessels. Tremor refers to rhythmic shaking of a body part. Tremor is a symptom of many diseases, including Parkinson's disease, essential tremor, orthostatic tremor, cerebellar disease, peripheral neuropathy, and alcohol withdrawal. Tremors may be classified as postural, rest, and action tremors. Tremor of a patient with stenosis of the left carotid artery decreased with acupuncture treatment. The acupoints were GB20, TE17, GV8 and GV11. This case shows that the acupuncture treatment is effective against tremor.