• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.777-789
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• 2001

The purpose of this study was to investigate the possibility of using surface electromyographic signals as a measure of muscle fatigue during the wheelchair propulsion. Subjects performed wheelchair exercise tests on a motor-driven treadmill with a constant-velocity of 1.25 m/sec. During each test, the raw EMC signals were acquired from the surface electrodes attached on the belly of five muscle groups: biceps brachii, pectoralis major. deltoid, triceps brachii, and trapezius. The median power frequency(MPF), and the root mean square(RMS) amplitude were calculated for each cyclic contraction in order to quantify muscle fatigue. During the wheelchair propulsion, the MPF decreased and the RMS increased in the trapezius and deltoid. However, the decreasing MPF and the increasing RMS also fluctuated severly during dynamic muscle contractions. Therefore, the MPF and RMS values should be estimated with well-designed methods and used with caution to quantify muscle fatigue during wheelchair propulsion.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.10
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• pp.940-946
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• 2004

In this paper, an efficient real-time control architecture for autonomous navigation of powered wheelchair is developed. Since an advanced intelligent wheelchair requires real-time performance, the control software architecture of powered wheelchair is developed under Linux real-time extension Real-time Application Interface (RTAI). A hierarchical control structure for autonomous navigation is designed and implemented using real-time processe and interrupts handling of sensory perception based on slanted surface LRF, emergency handling capability, and motor control with 0.1 msec sampling time. The performance of our powered wheelchair system with the implemented control architecture for autonomous navigation is verified via experiments in a corridor.

• Journal of Biomedical Engineering Research
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• v.11 no.1
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• pp.105-112
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• 1990

The main concepts in the design and construction of an motorized wheelchair for loading in the tar which is intended to drive a disabled to long distance. The wheelchair is basically a powered and folding, so it is designed to motorized manual wheel- chair by modularity method. The wheelchair hrs been installed with a power motor module, battery module, and drive & control module. The goal of this project is to develop a wheelchair that has multifunction and operated disabled who has variety impairment. So we ave currently working. Experimental results of the system approach our purpose, which is improved maneuverability, safety and can be loaded.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.3
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• pp.161-167
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• 2018

The improvement of the social environment and the rapid development of medicine are making possible the age of 100. So a great number of countries including Korea are rapidly becoming the aged society or the super aged society. The elderly are accompanied by discomfort and disability. A variety of systems are developed and distributed to overcome them. The electric wheelchair is an electric motorized system for people who can not manipulate a manual wheelchair. In this paper, we propose an autonomous driving platform for an electric wheelchair. Here we use QR (Quick Response) code for self-localization. We also present real test results of the proposed system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5738-5743
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• 2014

This paper evaluated an electric wheelchair control algorithm by slope recognition on uneven terrain. Nowadays, the population using wheelchair has been increasing rapidly due to increases in the elderly population. On the other hand, most wheelchairs are directly controlled by the user without any device capable of securing the safety of the user. This causes difficulties in wheelchair control from the influence of gravity on the slope. This paper proposes a vehicle control algorithm that can move a wheelchair similar to moving on a plane. At that time, sensors are not used to recognize the degree of the slope. All processes were verified by simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.41-49
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• 2005

Electromyogram (EMG) signal generated by voluntary contraction of muscles is often used in rehabilitation devices because of its distinct output characteristics compared to other bio-signals. This paper proposes a novel EMG-based human-computer interface for electric-powered wheelchair users with motor disabilities by C4 or C5 spine cord injury. User's commands to control the electric-powered wheelchair are represented by shoulder elevation motions, which are recognized by comparing EMG signals acquired from the levator scapulae muscles with a preset double threshold value. The interface commands for controlling the electric-powered wheelchair consist of combinations of left-, right- and both-shoulders elevation motions. To achieve a real-time interface, we implement an EMG processing hardware composed of analog amplifiers, filters, a mean absolute value circuit and a high-speed microprocessor. The experimental results using an implemented real-time hardware and an electric-powered wheelchair showed that the EMG-based human-computer interface is feasible for the users with severe motor disabilities.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.7
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• pp.552-556
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• 2016

Obstacle detection is a key feature in the safe driving control of electric wheelchairs. The suggested obstacle detection algorithm was designed to provide obstacle avoidance direction and detect the existence of cliffs. By means of this information, the wheelchair can determine where to steer and whether to stop or go. A 3D depth camera (Microsoft KINECT) is used to scan the 3D point data of the scene, extract information on obstacles, and produce a steering direction for obstacle avoidance. To be specific, ground detection is applied to extract the obstacle candidates from the scanned data and the candidates are projected onto a 2D map. The 2D map provides discretized information of the extracted obstacles to decide on the avoidance direction (left or right) of the wheelchair. As an additional function, cliff detection is developed. By defining the "cliffband," the ratio of the predefined band area and the detected area within the band area, the cliff detection algorithm can decide if a cliff is in front of the wheelchair. Vehicle tests were carried out by applying the algorithm to the electric wheelchair. Additionally, detailed functions of obstacle detection, such as providing avoidance direction and detecting the existence of cliffs, were demonstrated.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.140-148
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• 2017

Accidents involving wheelchair accessible vehicles have been frequently occurring since the introduction of these vehicles in the Korean market. However, detailed regulations, which are required to ensure the safety of the wheel-chair occupants, are unavailable. In this study, both domestic and international vehicle safety regulations are analyzed in order to select the regulations that are similar to the transportation environment of Korea. Sled tests with an actual wheel-chair accessible vehicle were carried out based on the analyzed regulation requirements, as well as the values of the HIC, belt loads, dummy movements, and wheelchair movements. The test results showed that the movements of the dummy and the wheelchair did not meet the criteria of the regulation due to the improper positioning of the restraint systems.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.477-486
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• 2010

This study aims at establishing a sizing system required for producing ready-made clothes which can fit the body shape of disabled men using wheelchair. It measured the bodies of 178 adult men using wheelchair and compared the sizing system of German adult men using wheelchair (1984) with KS system(KS K0050, 2004) in order to establish standards of the sizing system. AS a result, in terms of classification of body shapes, KS system cover more types of disabled men's body shapes and especially, A types (Drop 15.6) showed the widest coverage with 32%. In classification of heights, the widest range of height was 170 cm, and Korean men's four sizes between 158 cm and 176 cm covers 88.2% of disabled men's body shape. For chest size, 91.1% of disabled men's chest sizes were included in seven sizes, which are 4 cm intervals between 88 cm and 112 cm with 100 cm standard. In consideration of the ranges of height and chest, the general sizes (A types; 11 sizes, B types; 3 sizes, Y types; 5 sizes) are selected to present the standardized measurements. Basic parts of the upper garment sizing system for disabled men using wheelchair were height-chest-waist size.

• Journal of Sensor Science and Technology
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• v.13 no.1
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• pp.20-26
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• 2004

For the disabled persons who can't use their limbs, motorized wheelchair that is activated by voice recognition module employing speaker independent method, was implemented. The wireless voice transfer device was designed and employed for the user convenience. And the wheelchair was designed to operate using voice and keypad by selection of the user because they can manipulate it using keypad if necessary. The speaker independent method was used as the voice recognition module in order that anyone can manipulate the wheelchair in case of assistance. Using the implemented wheelchair, performance and motion of the system was examined and it has over than 97% of voice recognition rate and proper movements.