• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.518-523
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• 2015

This paper proposes a gait phase classifier using a Recurrent Neural Network (RNN). Walking is a type of dynamic system, and as such it seems that the classifier made by using a general feed forward neural network structure is not appropriate. It is known that an RNN is suitable to model a dynamic system. Because the proposed RNN is simple, we use a back propagation algorithm to train the weights of the network. The input data of the RNN is the lower body's joint angles and angular velocities which are acquired by using the lower limb exoskeleton robot, ROBIN-H1. The classifier categorizes a gait cycle as two phases, swing and stance. In the experiment for performance verification, we compared the proposed method and general feed forward neural network based method and showed that the proposed method is superior.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.581-596
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• 2010

The purposes of this study are to investigate and analyze the level of information and the state of digital divide of the disabled by surveying the demand for information and communication assistive devices, and to provide basic data for plans on the development and utilization of information and communication assistive devices. In order to understand the actual condition and the state of digital divide of persons with disabilities, the differences of possession and accessibility of information technology devices, usage ability, and utilization were analyzed according to the disability profile by using the T-test. The results show that there are significant differences (T=-2.510*) of possession and accessibility of information technology devices with respect to the disability profile, and that the disabled have lower possession and accessibility of devices than the non-disabled. Result of this study's demand forecast shows that about 28% of total respondents are currently using information and communication assistive devices, and a majority (67%) of them answered that the use of assistive devices lend great help to their lives. The proportion of those who have been supported by the government or related organizations with information and communication assistive devices were 36% of the total respondents, and those satisfied with the performance of the devices were 46% of the total responses. Meanwhile, only 36% of total users answered that the operation and use of functions of the devices was easy and convenient, responding that the difficulty of operating assistive devices was the greatest inconvenience. Moreover, the general requests of respondents in regards to the devices were stabilization of device performance, miniaturization of size, simplification of buttons, and reduction of weight.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.425-433
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• 2014

The purpose of the study was to investigate the effect of CAD (Computer Aided Design) based alpine mono-ski bucket design on disabled ski athletes' kinematic characteristics. Two national team ski athletes with LW11 disabilities (Locomotion Winter Classification) category for sit ski participated in both pre and post experiment. Both of the subjects performed 3 trials of carved turn on a ski slope under two conditions. Where, subject "A" performed pre experiment with personal bucket and post experiment with the newly developed CAD based bucket whereas, Subject "B" as control subject performed both pre and post experiment with his personal bucket. For the experiment, 24 Infrared cameras were positioned on the ski slope which covered the path of the ski turn. Also, motion capture suit with reflective markers were worn by both subjects. In the result, decrement in medial/lateral displacement of COM, anterior/posterior displacement of COM, flexion/extension angle of trunk as well as velocity losing rate of COM was observed in subject "A" when using the newly developed CAD based bucket. In contrast, no larger effect on performance was observed when using personal buckets. In conclusion, the findings obtained from the study indicated effectiveness of newly developed CAD based bucket by reducing excessive movement of hip and trunk which is an important factor to perform an effective turn.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.2
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• pp.133-139
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• 2016

An electric wheelchair is a assistive device to maneuver on the ground. Tip-over of an electric wheelchair is increasing every year. Dynamic stability metric test item in KS P 7176 has not ensured safety of electric wheelchair on the slope. This study presents design the foldable electric wheelchair that can load in the car and analysis of tip-over measurement which is easily computed for electric wheelchair. Wheelchair frame is designed with a four-bar link mechanism for a foldable structure, and seat module, battery and power driving module can be separated. This analysis is performed during a maneuver on the ground by force-moment stability metric. Several elements, center of gravity position, rotational radius and acceleration, were evaluated how to affect stability metric. This stability metric can reduce tip-over of wheelchair and provide a clue to make of dynamic stability test item.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1099-1108
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• 2023

The mortise view radiography procedure is an ankle joint examination and observes the presence of trauma, sprain, or dislocation suspected in the ankle joint. The auxiliary equipment used during the mortise view radiography procedure can generate artifacts in the radiograph images and is not diverse enough to be custom-made for each patient; not cost-efficient. The purpose of this study is to create a custom assistive device to support mortise view radiography procedure. This study utilized 3D printing technology to create the mortise view radiography procedure assistive device (ShinHan Device; SHD). The lengths of the tibiotalar joint (TTJ), talar calcaneal joint (TCJ), and medial joint (MJ) were measured and evaluated by five researchers using both SHD and the prototype Hologic tool. The mean ranges were found to be 39.42-39.47 mm for TTJ, 31.41-31.57 mm for TCJ, and 21.21-21.23 mm for MJ while using SHD device. On the other hand, the measurements showed mean ranges of 39.73-39.79 mm for TTJ, 31.46-31.50 mm for TCJ, and 21.31-21.35 mm for MJ while using the Hologic tool. Based on this study results, the error ranges at all positions decreased by 24% for TTJ, 17% for TCJ, and 36% for MJ when using SHD device compared to the Hologic tool. Moreover, when SHD was used, it allowed for a highly reproducible examination posture (ICC = 0.99), and it enabled the acquisition of radiograph images without artifacts, which were present in the Hologic tool.

• The Journal of Korea Robotics Society
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• v.10 no.2
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• pp.61-69
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• 2015

In this paper, we propose and examine the feasibility of the robot-assisted behavioral intervention system so as to strengthen positive response of the children with autism spectrum disorder (ASD) for learning social skills. Based on well-known behavioral treatment protocols, the robot offers therapeutic training elements of eye contact and emotion reading respectively in child-robot interaction, and it subsequently accomplishes pre-allocated meaningful acts by estimating the level of children's reactivity from reliable recognition modules, as a coping strategy. Furthermore, for the purpose of labor saving and attracting children's interest, we implemented the robotic stimulation configuration with semi-autonomous actions capable of inducing intimacy and tension to children in instructional trials. From these configurations, by evaluating the ability of recognizing human activity as well as by showing improved reactivity for social training, we verified that the proposed system has some positive effects on social development, targeted for preschoolers who have a high functioning level.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.3
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• pp.66-71
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• 2006

Some wheelchair users with neuromuscular disorders experience involuntary extensor thrusts, which may cause injuries via impact with the wheelchair, cause the user to slide out of the wheelchair seat, and damage the wheelchair. Knowledge of the human-generated forces during an extensor thrust is of great importance in devising safer, more comfortable wheelchairs. This paper presents an efficient method for identifying human-generated forces during an extensor thrust. We used an inverse dynamic approach with a three-link human body model and a system for measuring human body motion. We developed an experimental system that determines the angular motion of each human body segment and the force at the footrest, which was used to overcome the mathematical indeterminacy of the problem. The proposed method was validated experimentally, illustrating the force-identification process during an extensor thrust.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.389-396
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• 2012

Objective: The aim of this study is to design an auto showering system regarding bed type for old people or bedridden patients. Background: The rapid growth concerning the aging population leads to an increase in elderly bedridden patients living in senior care centers and hospitals where care givers have difficulty bathing older people with limited mobility. Method: In this study, a showering equipment for experiment was based on anthropometric and researching existing products. The nozzle position was optimized by showering tests and simulations using showering equipment. Results: The problems regarding the existing products were analyzed and the nozzle position was optimized through showering tests. The number, position, and spraying angle of the nozzle were optimized through showering simulations. The automatic showering system concerning bed type was designed by considering their results. Conclusion: When designing an automatic showering system, the most important design element involves determining the position of nozzle and angle of water injection and the number of nozzles. The system was developed by applying the results through user centered-research. Application: The user centered-research for developing products was applied directly in order to develop automatic baths, showering products etc. Furthermore, it was also available to be applied towards senior friendly products.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.49-53
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• 2009

In this paper, we compared wheelchair seating system between wheelchair users with cerebral palsy and spinal cord injuries. Wheelchair seating system is divided into three parts, seating components, seating cushion, and special functions. Seating components are composed of 10 sections, such as headrest, footrest, etc. There are 4 seating cushions including gel, form, hybrid, and air. Also leg elevation, seat elevation, tilt-in-space, reclining, and standing are special function of the wheelchair. There are 10 wheelchair users, 5 with celebral palsy, and 5 with spinal cord injuries who have participated in this study. 10 wheelchair users have been customers of rehabilitation technology center in national rehabilitation center. On the result, SCI group mostly uses headrest, and Humeral blocks (seating components), air cushion (seating cushion), and tilt in space, reclining (special functions). On the other hand, CP group uses adductor, abductor, and pommel (seating components), form cushion (seating cushion), and some of CP group uses reclining (special functions)

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.17-25
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• 2011

This paper aims to find the optimal control gain for enhancing the convenience of electric walking frames and design a control algorithm. With the recent advances in medical technology, there has been a rapid increase in the aging population and a variety of mobile walking frames have been developed for improvement of the quality of life. However, the manual walking frames of such mobile aids don't have any electric motor which helps facilitate elderly users' walking and thus are not efficient enough for the old people of weak strength to use especially when moving on uneven surfaces such as slopes or thresholds. The types of electric walking frames have been developed to overcome such inefficiency. Electric walking frames require users' control operations for motor driving unlike manual frames. Therefore, when they are not properly handled, it causes considerable inconvenience to their users. The present study compared the electric walking frames with manual ones in terms of operational convenience and attempted to improve the user convenience of walking frames varying the control value for user convenience based on certain standards. This paper presented a haptic sensor designed to recognize the will to walk and measure the degree of convenience and proposed a control algorithm for improvement of convenience. For user convenience, this paper evaluated the relative convenience of walking frames in view of changing differences between the center of vehicle (COV) and the center of position (COP). With the employment of an electric walking frame and a new measuring method, all the processes were experimentally tested and validated.