• 한국정밀공학회지
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• 제26권4호
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• pp.82-90
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• 2009

Pneumatic cylinder is one of the low cost actuation sources which have been applied in industrial and prosthetic application since it has a high power/weight ratio, a high-tension force and a long durability However, the control problems of pneumatic systems, oscillatory motion and compliance, have prevented their widespread use in advanced robotics. To overcome these shortcomings, a number of newer pneumatic actuators have been developed such as McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle (PAM) Manipulators. In this paper, one solution for position control of a robot arm, which is driven by two pneumatic artificial muscles, is presented. However, some limitations still exist, such as a deterioration of the performance of transient response due to the changes in the external load of the robot arm. To overcome this problem, a switching algorithm of the control parameter using a learning vector quantization neural network (LVQNN) is proposed in this paper. This estimates the external load of the pneumatic artificial muscle manipulator. The effectiveness of the proposed control algorithm is demonstrated through experiments with different external working loads.

• Journal of Biosystems Engineering
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• 제29권6호
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• pp.531-538
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• 2004

This study examined the muscle fatigue of the erector spinae according to box size during lifting activity. Ten healthy adult man participated in the experiment for lifting the boxes 10 times with 0.2 lift/s frequency. Bilateral surface EMG (Electomyogtamphy) recordings were made regarding M. (Muscle) Longissimus, M. Iliocostal and M, Multifidus activity throughout lifting working. The median frequency in back muscle fatigue was investigated using power spectral analysis of surface EMG. When the box larger than shoulder width was lifted, the muscle fatigue of M, Multifidus was shown larger than one of the other muscles. Accordingly, the result far M. Multifidus can be applied in optimizing design parameter of box. Also, the standard of box width for box makers have to be below about 420 mm, being average shoulder width of adult male.

• 한방재활의학과학회지
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• 제19권2호
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• pp.289-302
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• 2009

Objectives : This study was performed in order to investigate the relation of body composition analysis and radiological parameter(lumbosacral angle, lumbar lordortic angle, lumbar gravity line). Methods : This study was carried out with the data from comprehensive medical testing. 75 subject aged 20-59 performed the segmental bioelectrical impedance analysis, questionnaire. And lumbosacral angle, lumbar lordortic angle and lumbar gravity line were measured in the standing position x-ray. Then we analyzed the data. Results : Low back pain(LBP) prevalence in high obesity index(Body Mass Index(BMI), Percentage of Body Fat(PBF), Waist Hip Ratio(WHR)) group was higher than LBP prevalence in normal obesity index group(p<0.01). In LBP group, lumbosacral angle, lumbar lordortic angle were significantly lager than Non-LBP group(p<0.001). And 75% of LBP group indicated abnormal lumbar gravity line ratio(0.67 < Normal lumbar gravity line ratio <1.00). When it comes to analyze relation between obesity index and radiological parameter, no-significant change was seen. Conclusions : This study carried as following research after the study on relation of obesity, LBP and trunk muscle strength. Results from this investigation showed positive correlation between obesity and LBP prevalence. But obesity index didn't indicate significant correlation with structural changes of lumbar vertebrae. When considering prior research, trunk muscle strength changes were more related to LBP prevelence in obese people. This results are expected to explain causes of LBP in obese group.

• Journal of Nutrition and Health
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• 제25권6호
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• pp.485-491
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• 1992

남성호르몬인 testosterone 투여가 정상 암컷쥐의 체중, 체구성성분(체단백질, 체지방), 에너지 대사 및 근육단백질 대사에 미치는 영향을 조사하였다. Testosterone propionate를 체중 1kg당 1mg(1mg/kg)으로 10일간 투여했을 때 식이섭취량은 변화하지 않았음에도 체중 및 체단백질, 체지방은 유의적으로 증가하였다. 반면 testosterone propionate를 4번 또는 10mg/kg으로 투여 시에는 체단백질만 유의적으로 증가하였고 체지방은 영향을 받지 않았다. Testosterone propionate에 의한 체내 에너지축적(energy gain) 및 에너지 이용율(gross energetic effciency) 증가는 1mg/kg의 투여량에서만 관찰되었다. 근육조직(gastrocnemius muscle)의 무게, 단백질 및 RNA함량은 모든 투여량에서 유의적으로 증가하였으나 단백질 합성율은 어느 투여량에서도 영향을 받지 않았다. 이러한 결과를 통해 testosterone이 체중 및 체단백질, 체지방에 미치는 영향은 투여량에 크게 의존하며 testosterone의 근육단백질 증진 효과는 단백질 합성율에는 영향을 미치지 않고 단백질 분해율을 저하시킴으로써 발휘된다는 것을 알 수 있다.

• 대한인간공학회지
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• 제31권2호
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• pp.379-388
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• 2012

Objective: This study developed a new shower carrier prototype to reduce caregivers' muscle burden and to increase use convenience by reflecting the needs of domestic long-term care institutions. Background: In the long-term care institutions, one of the ADL(Activities of Daily Life) factors is bathing/showering. Recently, bath/shower-assisting equipment is actively being introduced in care institutions to reduce the caregivers' care cost, but most of the domestic equipment was designed to imitate foreign products and rarely reflected the needs of care institutions. Method: Based on Korean elderly people's body information, the bed size(length: 1,900mm, width: 650mm) was set-up, and a variable headrest with a newly designed headform was developed to provide the comfort for the elderly and convenience for caregivers. To reduce caregivers' muscle burden on transferring and showering activities, a 3-step column lifting module equipped with dual actuators(lowest/highest levels from the ground: 600/1,100mm, Stroke: 500mm) was developed, and the wheelbase parameter(length: 1,250mm, width: 580mm) was defined securing the turn-over safety of the shower carrier. The drivability tests were performed for the prototype and foreign product, and the male and female subject's muscle activities were measured through the tests. Results: The structural stability of the shower carrier prototype was secured by finite element analysis, and the muscle activities of the subjects through the drivability tests largely decreased in the prototype, compared to the foreign product. Conclusion: In this study, a new shower carrier prototype was developed to possibly reduce caregivers' muscle burden and to increase use convenience based on the needs of long-term care institutions. It was expected that the drivability performance of the prototype could be relatively superior to that of the foreign product. Application: The results obtained from the study can be applied for the optimal development of a shower carrier including other equipment to effectively care for the elderly.

• 대한물리의학회지
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• 제15권2호
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• pp.83-91
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• 2020

PURPOSE: Postural and structural asymmetry due to muscle imbalances around the lower back and pelvis are the causes of back pain. Muscle imbalances in patients with chronic low back pain affect the pelvic tilt and movement, and it is necessary to assess the pelvic movement ability using the appropriate tools to determine the mediating effects of lower back pain. This paper reports the reliability and validity of the Sensbalance Therapy Cushion (STC) for pelvic movement and proprioception. METHODS: In this study, the Wii balance board (WBB) was used as a golden standard for pelvic movement measurements. FABQ, KODI, Myovision, and Pelvic movement were measured in 50 patients with chronic low back pain. The correlation between the lower-back muscle activity and pelvic movement was checked. The pelvic movement parameter was measured twice to determine the intra-rater reliability. RESULTS: The STC showed high test-retest reliability in the pelvic tilt measurements (ICC = .672 - .809). The test-retest reliability of proprioception measurements (ICC = .588 - .859) and reaction time measurements (ICC = .542 - .836) were also high. The relationship between the WBB and STC showed a significant positive correlation with the pelvic tilt test (p < .01). The posterior pelvic tilt and lower-back muscle activity showed a significant negative correlation (p < .01). The pelvic left tilt and lower-back muscle activity showed a significant negative correlation (p < .05). CONCLUSION: The results revealed the high reliability and validity of the STC. Therefore, the STC can be used as an objective measuring device for evaluating pelvic tilt, proprioception, and reaction time in low back pain patients.

• 한국전문물리치료학회지
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• 제14권1호
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• pp.28-36
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• 2007

The aim of this study was to identify the effect of suspension unloading (SU) and electrical stimulation upon the development of neonatal muscular system. For this study, the neonatal rats were randomly divided into three groups: a control group, an experimental group I, and an experimental group II. The SU for experimental group I and II was applied from postnatal day (PD) 5 to PD 30. The electrical stimulation for soleus muscle of experimental group IIwas applied from PD 16 to PD 30 using neuromuscular electrical stimulation (NMES), which gave isometric contraction with 10 pps for 30 minutes twice a day. In order to observe the effect of SU and ES, this study observed myocyte enhancer factor 2C (MEF2C) and vascular endothelial growth factor (VEGF) immunoreactivity in the soleus muscles at PD 15 and PD 30. In addition, the motor behavior test was performed through footprint analysis at PD 30. The following is the result. At PD 15, the soleus muscles of experimental group Iand II had significantly lower MEF2C, VEGF immunoreactivity than the control group. It proved that microgravity conditions restricted the development of the skeletal muscle cells at PD 15. At PD 30, soleus muscles of the control group and experimental group II had significantly higher MEF2C, VEGF, immunoreactivity than experimental group I. It proved that the NMES facilitated the development of the skeletal muscle cells. At PD 30, it showed that SU caused the decrease in stride length of parameter of gait analysis and an increase in toe-out angle, and that the NMES decreased these variations. These results suggest that weight bearing during neonatal developmental period is essential for muscular development. They also reveal that NMES can encourage the development of muscular systems by fully supplementing the effect of weight bearing, which is an essential factor in the neonatal developmental process.

• Physical Therapy Rehabilitation Science
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• 제10권1호
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• pp.32-39
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• 2021

Objective: The weakness of muscle strength due to stroke affects the posture control and gait in the patients with stroke. Stroke This study examined the effects of the stair climbing training with functional electrical stimulation on muscle strength, dynamic balance, and gait in individuals with chronic stroke. Design: Randomized controlled trial. Methods: Total forty-eight patients were randomly assigned to the 3 groups. Participants randomly divided to stair climbing training with functional electrical stimulation group (SCT+FES group, n=16), stair climbing training group (SCT group, n=16) and control group (n=16). Subjects in the SCT+FES group and SCT group performed stair walking training with and without functional electrical stimulation for 30 minutes, 3 sessions per week for 4 weeks and all subjects received conventional physical therapy for 30 minutes with 5 sessions per week for 4 weeks. Outcome measurements were assessed using the sit-to stand Test for strength, timed up and go test and modified-timed up and go test for dynamic balance, and 10m walk test and GaitRite system for gait. Results: In the SCT+FES group, subjects have been shown the significant increase in lower extremity strength (p<0.05), significantly improve in dynamic balance (p<0.05), and significantly improve in their temporal gait parameter (p<0.05). The SCT+FES group was significantly better than other groups in all parameters (p<0.05). Conclusions: This result suggested that the SCT+FES may be effective strategy to improve muscle strength, dynamic balance, and gait for individuals with chronic stroke.

• 대한의용생체공학회:의공학회지
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• 제15권2호
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• pp.167-174
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• 1994

In this paper, a DSP and microcomputer-based EMG controlled functional electrical stimulation (FES) system, for restoring walking of paraplegics at the patients' own command, is presented. The above-lesion EMG is a time-varying nonstationary signal and its autoregressive (AR) parameters are identified by the nonstationary identification algorithm using a DSP chip. The identified AR parameters are used for the cloassification of the function and the control of the movement. The below-lesion response-EMG signal is used as a measure of muscle fatigue. This FES system is designed to measure muscle fatigue and control the stimulation intensity according to the amplitude of the response-EMG signal. While the automatic electrical intensity control is obtained by identifying the movement, the proposed FES system is suitable for the automatic control of paraplegic walking.

• Advances in nano research
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• 제14권1호
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• pp.17-25
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• 2023

Gold nanoparticles have recognized a promising drug carriers in many diseases. These nanoparticles could carry anti-inflammatory drugs in the case of muscle injury and for fatigue relief. On the other hand, specific surface of this kind of nanoparticles could be critical in amount of drug they could carry. Therefore, in this study, we explore different methodology and influencing parameters on the specific surface of gold nanoparticles. After specifying the main parameters, different machine learning and artificial neural network are adopted to model the effects of different parameters. Furthermore, response surface methodology is utilized to obtain a quadrilateral relationship between different parameters and specific surface. The results indicate that concentration of the gold salt solution is the most important parameter in increasing the size of gold nanoparticle and, as a consequence, increasing specific surface. Moreover, the ability of gold nanoparticles in prolonging retention of the drugs is discussed in detail.