• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.525-531
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• 2023

In Korea, which is entering a super-aged society, the number of elderly patients who have difficulty walking independently is expected to increase rapidly, and it is necessary to develop wheelchair products with various functions to improve the quality of life of people with walking disabilities. Recently, wheelchair power assist devices that provide propulsion power by being attached to a manual wheelchair has been developed and is entering the domestic and global markets. In this study, we compared and analyzed the process of obtaining medical device certification for wheelchair power assist devices in Korea, the United States, and Europe. In Korea, a Class 2 medical device certification process was developed in 2021, and in the US FDA, it corresponds to Class 2 like the existing electric wheelchair and must pass the 510k certification process. In the case of Europe, it is uniquely regulated as Class I, and the CE mark can be attached through a relatively easy self-declaration of conformity. The Korean medical device industry, which is struggling with MDR certification, a new European medical device regulation, should pay attention to the relatively easy entry into the global market for wheelchair power assist products.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.543-554
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• 1995

This paper describes the improvement of driving stability and the control system for INMEL-VII which is motorized manual wheelchair to satisfy requirements of the disabled The INMEL-VI was based on high maneuverability of the omnidirection drive and safety But the results of field tests about two years showed some problems to the disabled in daily life such as driving stability, Pm switching noise, and rotation of motor without driving command on negative slope. To solve the problems due to an increased DC motor power and applied to direct connection method in INMEL- VII. It improved the driving circuits and set switching frequency to 5KHz to eliminate the switching noise caused by PWM control of DC motor, As compare with the INMEL-VI, INMEL-VII is improved in driving stability by transfer the weight center to forward. The results of field testing proved the improvement of the driving stability and software algorithm It has been estimated to have a hlgh practical use for powered walking aids to the disabled's daily life.

• 재활복지
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• v.20 no.3
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• pp.141-161
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• 2016

This research is to anticipate problems of Ray's disabled experiment welfare vehicles for 17 drivers with disability, improving them. In addition it is to provide the criteria for ergonomic design based on perspective of drivers with disability by investigating 18 items of usability test. The results are as follows. First, satisfaction degree of Ray, disabled experiment welfare vehicle, was shown to be 3.88 which is higher than normal vehicles whose degree is 3.20. This showed that the disabled experiment welfare vehicle is the one with much improvement. Second, so as to develop a welfare vehicle it needs to take into account some factors including rear slope, wheelchair locker, seat belt, safety grip, and high roof. Third, in case of rear slope, high roof and width of manual or automatic wheel chairs should be considered and motor-operated device should also be taken into account for safety lockers, which make a wheelchair firmly fixed. Moreover, motor-operated seat and rear slope can be chosen for either of the disabled and the elderly.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.153-161
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• 2015

In the present study, as part of the technology development (Quality of Life Technology, QoLT) to improve the socio-economic status of people with disabilities as an extension of these studies, we propose the development of the smart wheelchair system and navigation technology for stable and safe driving in various environments. For the disabled and the elderly make driving easy and convenient with manual/autonomous driving condition, we firstly develop the user-oriented smart wheelchair system with optimized sensors for environment recognition, and then we propose a navigation framework of a hierarchical structure to ensure real-time response, as well as driving stability when traveling to various environmental changes, and to enable a more efficient operation. From the result of several independent experiments, we ensure efficiency and safety of smart wheelchair and its navigation system.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1110-1118
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• 2011

The recent power add-on drive wheelchairs (PADWs) provide greater physical activity and easier transportability and may be an excellent alternative for the typical manual and powered wheelchairs. The driving system consists of a motor and a motor driver is the most important component of the PADW In this paper, design, implementation, and testing of a driving system for a PADW are presented. To design the output power and torque for the driving system, the equation of motion has been investigated. The motor and driver were fabricated with precise machining and assembled to implement our prototype driving system. The dynamometer test has been carried out using the prototype in order to examine the torque of the system. The experimental results demonstrates that the designed driving system can provide enough output power and efficiency for utilization in a PADW.

• Journal of Drive and Control
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• v.16 no.3
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• pp.8-15
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• 2019

Wheelchair users experience difficulty when using transportation. This is because wheelchair users must use transportation means together with wheelchairs. Therefore, in this paper, we developed a wheelchair storage system for passenger's car trunk. The mechanism is designed to allow a wheelchair and the device to be housed simultaneously in the narrow space of the trunk of the sedan passenger car. Additionally, this wheelchair storage system has implemented an initial load reduction mechanism that can mechanically reduce the initial load. This wheelchair storage system verified the system's operability through the production of the prototype. This system was actually installed in the trunk of the sedan passenger's car to verify the storage process. The operation and storage process of the wheelchair storage system was been perfectly verified. This wheelchair storage system will help a lot of self-driver or an assistant (female or elderly) who use wheelchairs.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.80-85
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• 2011

This paper presents the design of the power-assisted controller for the in-wheel type smart wheelchair by using torque estimation that is predicted by relationship between input voltage and output wheel angular velocity. Nowadays, interest of the moving assistant aids is increased according to the increase in population of the elderly and the handicapped person. However some of the moving assistant aids have problems. For example, manual wheelchair has difficulty moving at the slope, because users lack the muscular strength of their arm. In electric wheelchair case, users should be weak by being decreased muscles of upper body. To overcome these problems, power-assisted electric wheelchair are proposed. Most of the power-assisted electric wheelchair have the special rims that can measure the user's power. In here, the rims have to be designed to install the sensors to measure user's power. In this paper, we don't design the rim to measure the man power. To predict the man power, we propose a control algorithm of the in-wheeled electric wheelchair by using torque estimation from the wheel. First, we measure the wheel velocity and voltage at the in-wheel electric wheelchair. And then we extract driving will forces by using proposed mathematical model. Also they are applied at the controller as the control input, we verify to be able to control in-wheel type smart wheelchair by using simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1465-1466
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• 2011

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.225-232
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• 2007

This work intends to investigate the effects of shift characteristics on the propulsion performance of a manual wheelchair with an automatic transmission. A planetary gear train is employed to generate a two-stage shift automatically, based on the distance traveled from rest. Motion analysis has been performed for measuring kinematic properties of the arm and then the inverse dynamics has been applied for estimating joint forces/torques. Then, a parametric study has been performed to find a set of the shift ratios and the shift intervals for optimizing propulsion performance. Results show that the propulsion performance is closely related to the shift condition. It is found that a short shift interval is desirable for a short distance propulsion. However, an optimum shift interval for a long distance propulsion is inversely proportional to the shift ratio approximately. Consequently, the automatic transmission can greatly lower the joint loadings by the speed reduction, which eventually contribute to prevent joint injuries of wheelchair users.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.464-469
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• 2001

This work provides the biomechanical evaluations of a manual wheelchair with a bi-directional driving system. The new propulsion strategy can be accomplished by employing a special gear system that converts the oscillatory motion of a handrim into the unidirectional output motion of a wheel. A main feature of the forward. backward propulsion is to supply continuous driving torque without break. Motion. analysis has been performed through 2-dimensional image processing for measuring the kinematic properties of the upper arm and fore arm. Then, the inverse dynamics analysis has been done for obtaining the joint torques, the handrim forces and input/output powers. Results show that the output power by the forward. reverse propulsion is almost twice as much as that by conventional propulsion. Also, the new propulsion is expected to reduce the fatigues and injuries at arm joints by employing more muscle groups for movement. In conclusion, the forward. reverse propulsion can greatly improve the performances of manual wheelchairs by providing better mobility as well as by guaranteeing several advantages from a biomechanical viewpoint. Future development of a manual wheelchair optimized for the bi-directional propulsion will further improve the propulsion performances.