• 제어로봇시스템학회논문지
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• 제18권2호
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• pp.69-75
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• 2012

This paper proposes a biomimetic finger module to be used in a lightweight hand prosthesis. The finger module consists of finger skeleton and an actuator module driven by SMA (Shape Memory Alloy). The prototype finger module can perform flexion and extension motions; finger flexion is driven by a contraction force of SMA, but it is extended by an elastic force of an extension spring inserted into the finger skeleton. The finger motions are controlled by feedback of electric resistance of SMA because the finger module has no sensors to measure length and angle. Total weight of a prototype finger module is 30g. In experiments the finger motions and finger grip force are tested and compared with simulation results when a constant contraction force of SMA is given. The experimental results show that the proposed SMA-driven finger module is feasible to the lightweight hand prosthesis.

• 한국지능시스템학회논문지
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• 제23권2호
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• pp.172-177
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• 2013

BCI (Brain Computer Interface)는 인간의 뇌에서 측정된 EEG (Electroencephalogram)를 활용하여 의수와 같은 기기를 조종할 수 있는 좋은 방법 중 하나이다. 본 논문에서는 EEG와 힘과의 관계를 알아보고자 최대수축악력 (MVC)의 25%, 50%, 75%로 3개의 등급으로 나누어 EEG 변화를 측정하였다. 얻어진 EEG data를 FFT와 power spectrum analysis로 ${\alpha}$, ${\beta}$, ${\gamma}$파로 나누어 각 파형의 파워 값을 구한 뒤, 구해진 EEG 파워 값을 PCA와 LDA를 사용하여 특징 추출 및 분류를 하였다. 실험 결과 25%의 악력을 가할 때 보다 75%의 악력 때 더 높은 EEG 파워의 증가를 확인하였고, 왼손과 오른손은 각각 52.03%와 77.7%의 분류율을 나타내었다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.644-649
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• 1994

Recent studies reveal that grip forces due to repeated mechanical vasocompressions are most significant for the genesis of vibration-induced which finger syndrome (VWF). Therefore, exerted grip force was regarded as a dependent variable in 2 experiments and the effects of noise and vibrations of different weighted acceleration levels were studied. Neither grip forces nor peripheral blood flow as indicated by finger skin temperature were influenced by noise or vibrations. the cause of VWF is therefore presumed to be a concomitant variable which correlates with weighted accelerations and with grip forces as well. A possible factor is the weight of hand-held vibrating tools.

• 재활치료과학
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• 제5권2호
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• pp.23-33
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• 2016

목적: 본 연구는 노인의 인지기능과 상지기능의 관련성을 알아보고자 하며, 근거 자료들을 P.I.C.O. 방법에 따라 제시하였다. 연구방법: 2015년 11월부터 2016년 1월까지 연구를 진행하였으며 2000년 1월부터 2015년 10월까지 국외 학술지에 개재된 논문을 Medline과 PubMed를 통하여 검색하였다. 검색용어로는 elderly, dementia, Alzheimer's disease, Mild cognitive impairment, age-related, aging, cognitive, upper extremity function, hand function, hand-grip strength, grip force, complex motor function, bimanual, dexterity, UE performance, coordination을 사용하였다. 연구결과: 본 고찰에 포함된 총 8개의 연구 중 7개의 연구에서 상지기능이 노화에 따라 영향을 받는다는 것으로 나타났고, 1개의 연구에서는 노화에는 영향을 받지 않으나, 쥐기 힘 및 성별에 의해 물건조작능력에 영향을 받는 것으로 나타났다. 연구 분석 결과 노인 및 치매환자의 인지기능이 상지기능에 영향을 미치며 상호 관련성을 보였다. 결론: 본 연구는 노인을 대상으로 인지기능이 상지기능에 미치는 영향 및 관련성을 알아보고자 하였으며, 인지기능 정도에 따른 작업치료 적용 및 중재기법을 선택하는데 근거 자료로 활용될 수 있을 것으로 사료된다. 향후 국내 연구에서는 다양한 평가도구를 사용하고 질적 수준이 높은 연구들이 체계적으로 이루어져야 할 것이다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.596-605
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• 1994

An efficient measurement and evaluation system for hand tool tasks will provide a practical solution to the problem of designing and evaluating manual tool tasks in the workplace. Few studies on the biomechanical analysis of hand postures and tool handling tasks exist because of the lack of appropriate measurement techniques for hand force. A measurement system for the finger forces and joint angles for analysis of manual tool handling tasks was developed in this study. The measurement system consists of a force sensing glove made from twelve Force Sensitive Resistors and an angle-measuring glove (Cyberglove$\^$TM/, Virtual technologies) with eighteen joint angle sensors. A biomechanical model of the hand using the data from the measurement system was also developed. Systems of computerized procedures were implemented integrating the hand posture measurement system, biomechanical analysis system, and the task analysis system for manual tool handling tasks. The measurement system was useful in providing the hand force data needed for an existing task analysis system used in CTD risk evaluation. It is expected that the hand posture measurement developed in this study will provide an, efficient and cost-effective solution to task analysis of manual tool handling tasks. These tasks are becoming increasingly important areas of occupational health and safety of the country.

• 제어로봇시스템학회논문지
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• 제22권12호
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• pp.1011-1020
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• 2016

This paper introduces a tactilely transparent soft glove composed of soft materials and flexible structures. Although it is hard to achieve a high grasping force with conventional grip-assist gloves made from soft material, the proposed glove can exert a high force by using a novel structure. This structure has a triangular shape composed of flexible structural frames, soft fabric, and belts. It can produce grip-assist moment compliantly without harmful force or misalignment with the human fingers. The whole finger part that comes into contact with objects is made of thin and soft fabric in order to facilitate sensation transference. The proposed tactilely transparent soft glove enables the user to manipulate various objects owing to both the softness and high grasping force; it helps lifting heavy weight objects as well as permitting delicate tactile feeling on the palm and fingers. The proposed concept was applied to a two-finger grip-assist device for validation. In addition, the experimental results regarding grasping objects, fingertip force, and grasping force are presented.

• 한국전문물리치료학회지
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• 제29권1호
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• pp.28-36
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• 2022

Background: It is known that hand strength and fingertip force are used as an indicator of muscle strength and are also highly related to the various chronic symptoms and even lifespan. To use the individual fingertip force (IFF) as a quantitative index for clinical evaluation, the IFF should be measured and analyzed with various variables from various subjects, such as the normal range of fingertip force and the difference in its distribution by disease. Objects: We tried to measure and analyze the mean maximum IFF distribution during grasping a cylindrical object in healthy adults and patients with spinal cord injury (SCI). Methods: Five Force-sensitive resistor (FSR) sensors were attached to the fingertips of 24 healthy people and 13 patients with SCI. They were asked to grip the object three times for five seconds with their maximum effort. Results: The mean maximum IFF of the healthy adult group's thumb, index, and middle finger was similar statistically and showed relatively larger than IFF of the ring and small finger. It is a 3-point pinch grip pattern. All fingertip forces of patients with SCI decreased by more than 50% to the healthy group, and their IFF of the middle finger was relatively the largest among the five fingertip forces. The cervical level injured SCI patients showed significantly decreased IFFs compared to thoracic level injured SCI patients. Conclusion: We expect that this study results would be helpful for rehabilitation diagnosis and therapy goal decision with robust further study.

• 보건행정학회지
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• 제29권3호
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• pp.303-311
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• 2019

Background: Cerebrovascular disease is included in four major diseases and is a disease that has high rates of prevalence and mortality around the world. Moreover, it is a disease that requires a high cost for long-term hospitalization and treatment. This study aims to figure out the correlation between grip strength, which was presented as a simple, cost-effective, and relevant predictor of cerebrovascular disease, and cerebrovascular disease based on the results of a prior study. And furthermore, our study compared model suitability of the model to measuring grip strength and relative grip strength as a predictor of cerebrovascular disease to improve the quality of cerebrovascular disease's predictor. Methods: This study conducted an analysis based on the generalized linear mixed model using the data from the Korea Longitudinal Study of Ageing from 2006 to 2016. The research subjects consisted of 9,132 middle old age people aged 45 years or older at baseline with no missing information of education level, gender, marital status, residential region, type of national health insurance, self-related health, smoking status, alcohol use, and economic activity. The grip strength was calculated the average which measured 4 times (both hands twice), and the relative grip force was divided by the body mass index as a variable considering the anthropometric figure that affects the cerebrovascular disease and the grip strength. Cerebrovascular diseases, a dependent variable, were investigated based on experiences diagnosed by doctors. Results: An analysis of the association between grip strength and found that about 0.972 (odds ratio [OR], 0.972; 95% confidence interval [CI], 0.963-0.981) was the incidence of cerebral vascular disease as grip strength increased by one unit increase and the association between relative grip strength and cerebrovascular disease found that about 0.418 (OR, 0.418; 95% CI, 0.342-0.511) was the incidence of cerebral vascular disease as relative grip strength increased by unit. In addition, the model suitability of the model for each grip strength and relative grip strength was 11,193 and 11,156, which means relative grip strength is the better application to the predictor of cerebrovascular diseases, irrespective of other variables. Conclusion: The results of this study need to be carefully examined and validated in applying relative grip strength to improve the quality of predictors of cerebrovascular diseases affecting high mortality and prevalence.

• Safety and Health at Work
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• 제11권4호
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• pp.458-465
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• 2020

Background: The aim of this study was to analyze the interaction between neck and/or wrist pain and hand grip strength (HGS) and to investigate factors (age, sex, neck disorders, and carpal tunnel syndrome) influencing the HGS of industrial quality proofing workers (N = 145). Methods: Standardized questionnaires [Neck Disability Index (NDI), Boston Carpal Tunnel Questionnaire] were used to evaluate existing neck and/or wrist pain. HGS measurements were performed in different wrist positions. Results: Significant differences between participants with and without neck pain were found in different wrist positions, in neutral wrist position right [without neck pain (n = 48) 46.34 (43.39 - 49.30); with neck pain (n = 97) 38.46 (36.20 - 40.72), F_(1,144) = 16.82, p < 0.001, ŋ_p² = 0.11] and left [without neck pain 44.06 (41.19 - 46.94); with neck pain 37.36 (35.13 - 39.58), F_(1,144) = 12.70, p < 0.001, ŋ_p² = 0.08]. A significant difference between participants with and without wrist pain was found for neutral wrist position right [without wrist pain (n = 105) 42.53 (40.37 - 44.70); with wrist pain (n = 40) 37.24 (33.56 - 40.91), F_(1,144) = 6.41, p = 0.01, ŋ_p² = 0.04]. Regression analysis showed significant results especially for steps two (age and weight, NDI) and three (age and weight, NDI, Boston Carpal Tunnel Questionnaire) for neutral position right (R² = 0.355, R² = 0.357, respectively). Conclusion: Neck pain has an impact on HGS but should be evaluated in consideration of age and sex.

• 한국운동역학회지
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• 제32권4호
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• pp.121-127
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• 2022

Objective: The purpose of this study was to investigate potential effects of transcranial direct current stimulation (tDCS) on bimanual force control capabilities in healthy young adults. Method: Eighteen right-handed healthy young adults (10 females and 8 males; age: 23.55 ± 3.56 yrs) participated in this crossover design study. All participants were randomly allocated to both active-tDCS and sham-tDCS conditions, respectively. While receiving 20 min of active- or sham-tDCS interventions, all participants performed bimanual isometric force control tasks at four submaximal targeted force levels (i.e., 5%, 10%, 15, and 20% of maximal voluntary contraction: MVC). To compare bimanual force control capabilities including force accuracy, variability, and regularity between active-tDCS and sham-tDCS conditions, we conducted two-way repeated measures ANOVAs (2 × 4; tDCS condition × Force levels). Results: We found no significant difference in baseline MVC between active-tDCS and sham-tDCS conditions. Moreover, our findings revealed that providing bilateral tDCS including anodal tDCS on left primary motor cortex (M1) and cathodal on right M1 while conducting bimanual force control trials significantly decreased force variability and regularity at 5%MVC. Conclusion: These findings suggest that providing bilateral tDCS on M1 areas may improve bimanual force control capabilities at a relatively low targeted force level.