• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.212-213
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• 2013

This paper proposes the algorithm of torque distribution in the electric wheel-chair using 2D joystick for drive safety. For the accurate driving performance, the specific and precise torque distribution is required in both wheels depending on signals of X-Y axis that is generated from 2D joystick. The signals of X-Y axis from joystick are transformed into the propulsion force and the torque reference. And the torque reference can be generated through the dynamic model of wheel-chair. The optimal dynamic characteristics of the electric powered wheelchair can be obtained, by adjusting the sensitivity coefficients of propulsion force and torque reference, In addition, the system takes smooth and stable control characteristics due to continuous torque output at all directions of joystick. The several simulations verify the usefulness of the proposed algorithm about torque distribution.

• Physical Therapy Korea
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• v.6 no.2
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• pp.56-66
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• 1999

The purpose of this study focused how to show physiological responses comparing exercise group and non exercise group for progressive maximal wheelchair ergometer exercise loading in complete paraplegia. It also examined the various factors which would be influenced physiological responses. Sixteen subjects have been investigated in this study, and the subjects are divided into two groups as follows: 1) exercise group (7 subjects) 2) non exercise group (9 subjects). Each test was terminated by physical exhaustion and/or an inability to maintain a flywheel velocity. The results were as follows: 1) No difference was noted in pulmonary function test between two groups. 2) $\dot{v}$ Emax value during maximal exercise was significantly different between the groups (p<0.05). The mean $\dot{v}$ Emax of exercise group was $69.67{\ell}/min$, non exercise group was $41.47{\ell}/min$. 3) $\dot{v}$ $O_2max$(${\ell}/min$) value during maximal exercise was significantly different between the groups (p<0.05). The mean $\dot{v}$ $O_2max$(${\ell}/min$) of exercise group was $1.72{\ell}/min$, non exercise group was $1.15{\ell}/min$. 4) $\dot{v}$ $O_2$ max(ml/kg/min) value during maximal exercise was significantly different between the groups (p<0.05). The mean $\dot{v}$ $O_2max$($ml/kg{\cdot}min$) of exercise group was $25.99ml/kg{\cdot}min$, non exercise group was $18.61{\ell}/min$. 5) Maximal heart rate(HRmax) value during maximal exercise was significantly different between the groups (p<0.05). The mean HRmax of exercise group was 180.43 beats/min, non exercise group was 175.00 beats/min. 6) $\dot{v}\;E/\dot{v}\;O_2$ value during maximal exercise was not significantly different between the groups (p>0.05). The mean $\dot{v}\;E/\dot{v}\;O_2$ of exercise group was $36.36{\ell}/{\ell}\;O_2$, non exercise group was $45.46{\ell}/{\ell}\;O_2$. Considering the results which explore the exercise group with paraplegia has shown the maximal aerobic power compared with non exercise group, regular and consistent physical training is highly assumed as a main factor to improve cardiopulmonary fitness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.419-427
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• 2020

This study was undertaken to address the difficulties and inconveniences of an electric wheelchair. We focused on improving usability of initially completed products by augmenting the prototypes designed in the previous study. For evaluation of usability, 10 elderly women aged over 65 years, capable of movements and physical activities in daily life, were enrolled as subjects. The experimental method included a subjective satisfaction questionnaire evaluation of the elderly women using the target product, and the observation evaluation was achieved using video recording data, etc. Usability evaluation revealed that the elevating sector requires improvement of intuition through separation of the elevating control panel and the driving control panel. Improvements in the driving sector include corrections of the front wheel mechanism or driving control algorithm, UI, and sudden stop system. Transferring section assessment revealed a necessity to secure structures and add structures that support power. We believe that based on the inconveniences and improvements presented in the usability evaluation, appending the existing prototype with complementary products will improve the quality of life of elderly women with limited mobility.

• Physical Therapy Korea
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• v.10 no.2
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• pp.71-84
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• 2003

The purpose of this study was to provide information on driving characteristics in persons with spinal cord injury through basic statistic analysis of the survey results. The survey was administered to 44 drivers with spinal cord injury. The subjects' general, neurologic and driving characteristics were analyzed, as well as the degree of difficulty in using their vehicles between tetraplegia and paraplegia. The results were as follows: thirty-five (79.6%) of forty-four respondents was men. The average age was 35.0 years old and the age at the time of injury was 29.0 years old. Their neurologic characteristics were tetraplegics 12 (27.3%) and paraplegics 32 (72.2%). Among complete lesions, the highest level those who could drive independently was C7. All the vehicles were equipped with special devices, including "power steering", "automatic transmission" and "hand controls". The vehicles for cervical cord injury were equipped with "grip bars" as well as for the degree of difficulty in using their vehicles, all the subjects felt that "moving the wheelchair in and out of their vehicles" was too difficult for them to do. We suggest that the driver training should be an essential part of the rehabilitation program for patients with spinal cord injuries to maximize their mobility in the community. This training seems to be essential in order to modify the standards of the Handicapped Drivers Ability Test and to aid the driver rehabilitation program in the health insurance payment system. Also, the driver rehabilitation training program should include instruction in that moving wheelchairs in and out of vehicles.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.340-347
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• 2008

Ubiquitous services are high quality and differentiated services which are provided for users by recognizing the context of users and environmental conditions actively. In this case, context-aware middleware is one of the most important technologies required to implement the ubiquitous services. In this paper, we propose a method for providing ubiquitous services in a specific user space effectively and monitoring human bio-sensors. That is, the design and implementation of intelligent home service middleware and monitoring bio-sensors based on context awareness is discussed here. Context information from various sensors is gathered, and suitable services are inferred and provided to users by the middleware system. In our approach, user services can be modelled easily by using facts and rules, and the system can be extended easily to support various ubiquitous services other than intelligent home services also. The system can be integrated with external applications and legacy systems effectively by using various protocols such as RMI, socket and HTTP, XML and etc. We have designed and evaluated various facts and rules for intelligent home services in real environments. Functionality evaluation with the system shows that ubiquitous services can be provided to users effectively in a home environment.