• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.4
• /
• pp.119-130
• /
• 2019

Purpose : The purpose of this study was to investigate the meta-analysis on the effects of action observation training on stroke patients' walking. Methods : Domestic databases (DBpia, KISS, NDSL, and RISS) were searched for studies that conducted randomized controlled trials (RCTs) associated with action observation training in adults after stroke. The search outcomes were items associated with the walking function. The 18 studies that were included in the study were analyzed using R meta-analysis. A random-effect model was used for the analysis of the effect size because of the significant heterogeneity among the studies. Sub-group and meta-regression analysis were also used. Egger's regression test was conducted to analyze the publishing bias. Cumulative meta-analysis and sensitivity analysis were also done to analyze a data error. Results : The mean effect size was 2.77. The sub-group analysis showed a statistical difference in the number of training sessions per week. No statistically significant difference was found in the meta-regression analysis. Publishing bias was found in the data, but the results of the trim-and-fill method showed that such bias did not affect the obtained data. Also, the cumulative meta-analysis and sensitivity analysis showed no data errors. Conclusion : The meta-analysis of the studies that conducted randomized clinical trials revealed that action observation training effectively improved walking of the chronic stroke patients.

• PNF and Movement
• /
• v.8 no.2
• /
• pp.1-8
• /
• 2010

Purpose : The purpose of this study was to investigate the effects of proprioceptive exercise (PE) using a trampoline and a balance board on a balance ability after stroke. Method : Sixteen chronic stroke patients participated. Participants were randomly assigned to the PE group or control group (8 experimental, 8 control). All of participants were in-patients at local rehabilitation centre and had been receiving a traditional rehabilitation program, five days a week. The PE group have additionally undergone for four weeks, three days a week, the PE using a trampoline and a balance board under supervision by a physical therapist but control group was not received any additional program except the traditional rehabilitation program. The position sense test used to assess a proprioceptive sense at a knee joint. The Berg Balance Scale (BBS) and the Timed Up & Go (TUG) test to measure the balance ability were carried out before and after the training. Result : After the training the error of position sense at knee joint of PE group significantly decreased compared to the control group. The PE group demonstrated a significant improvement in the scores of the BBS and TUG. Conclusion : The present study suggests that the PE program using a trampoline and balance board may become a useful tool for enhancing a balance ability in chronic stroke patients through the ennced proprioceptive position senses.

• PNF and Movement
• /
• v.16 no.3
• /
• pp.405-414
• /
• 2018

Purpose: The purpose of this study was to examine test-retest reliability and criterion-related validity of a trunk stability robot when measuring the weight-bearing symmetry static sitting and standing in stroke patients. Methods: For 27 stroke patients, weight-bearing symmetry was assessed twice, 7 days apart. The intraclass correlation coefficient (ICC2,1) and minimal detectable change (MDC) were used to examine the level of agreement between test and retest. The criterion-related validity of weight -bearing symmetry was demonstrated by Spearman correlation of modified Barthel index (MBI), the sit to stand test (STS), the timed up & go Test (TUG), and the function in sitting test (FIST). Results: the test-retest agreements were excellent for the weight-bearing symmetry of static sitting (ICC2,1: 0.90) and standing (ICC2,1: 0.89). It all showed that the acceptable MDC for the weight-bearing symmetry of static sitting and standing was 0.11 and 0.16, respectively (highest possible score<20 %), indicating that the measures had a small and acceptable degree of measurement error. The weight-bearing symmetry of static sitting was significantly correlated with the TUG(r=-0.45) and FIST(r=0.46)(p<0.05); the weight-bearing symmetry of static standing was also significantly correlated with MBI (r=0.65), TUG (r=-0.67), FIST (r=0.61)(p<0.01), and STS (r=-0.47)(p<0.05). Conclusion: The weight-bearing symmetry of static sitting and standing assessed by the trunk stability robot showed highly sufficient test-retest agreement and mild-to-moderate validity. It could also be useful for clinicians and researchers to evaluate balance performance and monitor functional change in stroke patients.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.15 no.4
• /
• pp.44-48
• /
• 2006

Recently, demand the ultra precision product which is increasing rapidly is used extensively frontier industry field such as semi-conductor, computer, aerospace, precision machine. Ultra precision processing is the portion that is very needed to NT in the field of mechanical engineering. The latest date, together with radical advancement of electronic and photonics industry, necessity of ultra precision processing is on the increase for the manufacture of various kernel parts those are connected with these industrial fields. Specially, require motion accuracy of high resolution of nm order in stroke of hundreds millimeters according as diameter of processing object great and processing accuracy rises. In this case ,the response speed absolute delay because inertial mass of moving part is very large. Therefore, real time motion error compensation becomes very hardly. In this paper, we used ultra precision cutting unit(UPCU) to cope such problem. a UPCU is designed and tested to obtain sub-micrometer from accuracy in diamond turning of flat surfaces. The thermal growth spindle error is compensated for real time using a UPCU driven by piezoelectric actuator along with a laser encoder displacement sensor.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.26 no.2
• /
• pp.151-157
• /
• 2017

Hydraulic equipment have been traditionally used for constructing machines with high power density and durability. In particular, pumps and motors are considered essential equipment, and are consistently investigated to find suitable methods for optimal utilization of their characteristics. A kinematic analysis of a swash-plate-type piston motor model using the hydraulic analysis program SimulationX$^{(R)}$ to model a nine-piston motor and simulate a swash-plate angle with a low-pulsation and high-efficiency performance of the motor has been provided in this paper. Finally, along with the theoretical consideration of the stroke, the effect of changing strokes and notch shape (V, U, non-type) on the pulsation is simulated to analyze and determine the effects of reduction in pulsation. The optimal swash-plate angle and stroke thus obtained will reduce the trial and error in future design.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.1
• /
• pp.31-39
• /
• 2016

This paper describes the design of an ankle rehabilitation robot for the force measurement of a severe stroke patient staying in a bed ward. The developed ankle rehabilitation robot was attached to a three-axis force/torque sensor that could detect force Fx, Fz, and torque Tz and measure the ankle rotation force (Fx) exerted on the ankle and the signal force Fz and torque Tz to be used as a safety device. The robot was designed and manufactured for bedridden stroke patients, and the robot program was manufactured to perform the flexibility rehabilitation exercise for ankle bending and to measure the ankle force to judge the degree of rehabilitation. According to the result of the characteristics test of the developed rehabilitation robot, it was safely operated while the ankle-bending flexibility rehabilitation exercise and the emergency situation were performed. Therefore, it is thought that the developed rehabilitation robot can be used for severe stroke patients.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.3
• /
• pp.155-162
• /
• 2004

This paper presents the fabrication procedure and the experiments for the 3-axis fine positioning stage proposed in［1］. First, the dynamic characteristics of the actuator and the stage are tested with the preload changed in order to validate the stage design specifications. Secondly, the performance of the stage is also evaluated on the accuracy associated with linear positioning, angular error, and straightness error. Experimental results show that the developed stage is accurate enough to be used for nanometer positioning. Through the analysis and experiment, the developed fine positioning stage are found to have a long stroke due to the magnetically preloaded PZT actuators, the minimum motion crosstalk due to the use of a ball contact mechanism and the compact design.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.12 s.177
• /
• pp.51-60
• /
• 2005

This paper describes a robust control scheme for high-speed and long stroke scanning motion of high precision linear motor system consisting of linear motor, air bearing guide and position measurement system using heterodyne interferometer. Nowadays, semiconductor process and inspection of wafer or LCD need high speed and long travel length for their high throughput and extremely small velocity fluctuations or tracking errors. In order to satisfy these conditions, linear motor system are widely used because they have large thrust force and do not need motion conversion mechanisms such as ball screw, rack & pinion or capstan with which the system are burdened. However linear motors have a problem called force ripple. Force ripple deteriorates the tracking performances and makes periodic position errors. So, force ripple must be compensated. To maximize the tracking performance of linear motor system, we propose the control scheme which is composed of a robust control method, Time Delay Controller (TDC) and a feedforward control method, Zero Phase Error Tracking Control (ZPETC) for accurate tracking a given trajectory and an adaptive force ripple compensation (AFC) algorithm fur estimating and compensating force ripple. The adaptive ripple compensation is continuously refined on the basis of tracking error. Computer simulation results based on modeled parameters verify the effectiveness of the proposed control scheme for high-speed, long stroke and high precision scanning motion and show that the proposed control scheme can achieve a sup error tracking performance in comparison to conventional TDC control.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.383-388
• /
• 2004

A piezoelectric actuator yields hysteresis effect due to its composed ferroelectric. Hysteresis nonlinearty is neglected when a piezoelectric actuator moves with short stroke. However when it moves with long stroke and high frequency, the hysteresis nonlinearty can not be neglected. The hysteresis nonlinearty of piezoelectric actuator degrades the control performance in precision position control. In this paper, in order to improve the control performance of piezoelectric actuator, an inverse modeling scheme is proposed to compensate the hysteresis nonlinearty problem. And feedforward - feedback controller is proposed to give a good tracking performance. The Feedforward controller is inverse hysteresis model, Nueral network and PID control is used as a feedback controller. To show the feasibility of the proposed controller and hysteresis modeling, some experiments have been carried out. It is concluded that the proposed control scheme gives good tracking performance

• Journal of Advanced Marine Engineering and Technology
• /
• v.12 no.4
• /
• pp.53-61
• /
• 1988

Speed of a diesel engine is usually controlled by the hydraulic governor which uses the centrifugal force of rotating fly balls for sensing the error speed. But for a recently developed high efficient, low speed and long stroke 2 cycle marine diesel engine, this governor doesn't work well enough because of too much changes of toraring force during one revolution of engine and too long uncontrollable time due to small numbers of cylinder. For improvement of jiggling phenomena and unstability various studies are being carried out, but they are not enough for a steep load change in a small ship's generator plant or at rough sea condition in a propulsion engine. In this paper, authors propose a new method to control a fuel before the change of angular velocity due to load change by feedforward the change of load, and find that the proposed method shows quite a good control performance in comparision to the customary PID control method by simulation using a digital computer for the various load change.