• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.241-250
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• 2022

It is known that chronic pain and injury of upper limb joint tissue in manual wheelchair users is usually caused by muscle imbalance, and the propulsion speed is reported to increase this muscle imbalance. In this study, kinematic variables, electromyography, and ultrasonographic images of the upper limb were measured and analyzed at two different propulsion speeds to provide a quantitative basis for the risk of upper extremity joint injury. Eleven patients with spinal cord injury for the experimental group (G_E) and 27 healthy adults for the control group (G_C) participated in this study. Joint angles and electromyography were measured while subjects performed self-selected comfortable and fast-speed wheelchair propulsion. Ultrasound images were recorded before and after each propulsion task to measure the acromiohumeral distance (AHD). The range of motion of the shoulder (14.35 deg in G_E; 20.24 deg in G_C) and elbow (5.25 deg in G_E; 2.57 deg in G_C) joints were significantly decreased (p<0.001). Muscle activation levels of the anterior deltoid, posterior deltoid, biceps brachii, and triceps brachii increased at fast propulsion. Specifically, triceps brachii showed a significant increase in muscle activation at fast propulsion. AHD decreased at fast propulsion. Moreover, the AHD of G_E was already narrowed by about 60% compared to the G_C from the pre-tests. Increased load on wheelchair propulsion, such as fast propulsion, is considered to cause upper limb joint impingement and soft tissue injury due to overuse of the extensor muscles in a narrow joint space. It is expected that the results of this study can be a quantitative and objective basis for training and rehabilitation for manual wheelchair users to prevent joint pain and damage.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1585-1592
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• 2018

Due to un-balancing weight allocation on the wheelchair the existing wheelchair system are faced with the risk of flipping or falling when a wheelchair goes up to a hill. In to order to be safer during riding the wheelchair, in this paper, we proposed a real-time new solution using the integrated Gyro Sensor and Tilt Sensor for controlling the balance. Because the typical property of wheelchair is for the special user who meets the difficulty in moving on foot the maintain the balance of wheel-chair systems have become important and helpful. In our method, we calculate the seat angle using information from Tilt Sensor. However, due to the law of inertia when a wheelchair is moving there is a deviation in the output value of Tilt Sensor. Therefore, we have to optimize the value of the angle by utilizing the acceleration that is the output of the Gyro Sensor. We took the advantages by using the combination of Gyro and Tilt sensors. Moreover, we also solved the consumption issue of the whole system. Through various experimentations with usage of ZigBee sensor module, the power consumption for the balancing system is reduced significantly.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.97-112
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• 2023

The purpose of this study is to design and test a new way of public transportation route guidance system for persons with disabilities, including wheelchair users. The guidance system is smartphone app-based, using, routes that involve disabled-friendly facilities in the vicinity can be searched. A database that contains publicly available data on low-floor bus services, location and extent of disabled-friendly facilities, and suitable subways and stations, was developed for this purpose. The app uses the database to access and query the required information. A pilot study was conducted to test the effectiveness of the guidance system. It was found that the system was able to convey information about the disabled-friendly routes and related guidance information even inside subway stations, effectively. The performance of the system was compared with route guidance services that do not explicitly use data on disabled-friendly services. A notable difference was observed in the travel time estimated by this program and other guidance services. The difference was around 4 to 15 minutes. This is significant savings for persons with disabilities if they use the app and service. The study thus shows that exclusive use of disabled-friendly data in route guidance will bring more benefits for persons with disabilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3360-3365
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• 2011

This paper deals with method to measure the user's driving-will force and to control the power-assisted wheelchair. To solve this problem, we extract the user's driving-will by using the mathematical motor model. And then, we get the linear and angular velocity at the center of the vehicle. Wheel velocities are also measured from center velocity. Finally, power-assisted electric wheelchairs are controlled by these data. Here all processes are verified by simulation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.143-144
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• 2019

본 논문은 현대에 신체활동(Physical activity)를 하지 않으면 심혈관계질환, 당뇨, 암, 골다공증 등과 같은 질환의 위험성을 가지고 있음에도 불구하고 공간부족, 시간부족, 날씨 등으로 제약을 받아 신체활동이 부족한 척수장애인의 들을 위한 스마트 휠체어 트레드밀을 개발함이다. 기존의 휠체어 트레드밀은 휠체어를 생활할 때 사용하는 대상자들에게 신체활동을 제공하였다. 스마트 휠체어 트레드밀은 경사(Slope-Incline, Decline)를 조절하여 개별마다 다른 건강체력능력에 운동강도(Exercise intensity)를 다르게 할 수 있다. 또한 스마트 휠체어 트레드밀은 거리측정, 속도측정이 가능한 센서를 부착하여 대상자의 운동량을 알 수 있을 뿐만 아니라 체중측정도 가능하여 대상자의 운동량에 대한 칼로리소모량을 얻을 수 있다. 이러한 스마트 휠체어 트레드밀과 VR(Virtual reality) 프로그램, 게임을 접목시켜 척수장애인들의 신체활동에 흥미를 증진 시킬 수 있다.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.3
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• pp.127-132
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• 2020

In this study, the process of providing information necessary to remove physical barriers such as road slopes that obstruct the activities of the disabled is in progress. Through experiments, we implement a quantified road surface roughness index that enables the implementation of IoT-based systems necessary for the elderly and the disabled to safely move to their destination. As a preliminary study, a road surface measurement device using a gyroscope was devised. To check the roughness and flatness of the road surface, X, Y displacement, and acceleration displacement were measured using a gyroscope. By calculating the measured data, the roughness and flatness of the road surface were quantified from 0 to 100. We implemented an algorithm that divides this index into 4 stages, displays it on a map, and provides it to users. Finally, a system for the disabled and elderly electric wheelchair users to secure basic mobility was established.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.259-260
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• 2020

기존의 전동휠체어를 사용하는 약자 또는 중증 장애인 등 지체(肢體)가 불편한 사람들이 휠체어 사용 시 생기는 문제점을 해소할 목적으로 시작되었다. 이는 전동휠체어가 보행 기구임에도 자동차에 준하는 교통사고에 대해 무방비하게 노출되고, 중증 장애인에 대한 이동권 보장이 아직 미흡하여 생기는 문제이다. 따라서 본 연구에서는 이러한 문제로 인한 불편함을 해소하고자 아이트래킹을 이용한 스마트 전동휠체어 기술을 적용하고자 한다. 루게릭병 등으로 인해 지체(肢體)의 움직임에 제한이 있는 사람들에게 보호자가 밀어주는 휠체어에 의존하는 것이 아닌 Eye-Tracker를 이용한 시선 추적(Eye-Tracking) 기술로 휠체어 동작이 가능하다. Web-Cam과 라즈베리 파이를 통해 얻은 전·후·좌·우의 영상정보를 디스플레이 화면에 송출한다. 그 후 Eye-Tracking 기술을 이용해 디스플레이 화면에 표시된 전·후·좌·우 이동에 관한 UI(User Interface)룰 사용자가 송출된 영상을 보면서 눈의 움직임만으로 선택해 휠체어의 방향을 제어한다. 또한 전동휠체어의 조작 실수로 다른 행인 또는 장애물과 충돌하는 문제점을 초음파 센서를 이용하여 일정 거리 내에 사물이나 사람이 있을 경우 디스플레이 화면에 경고표시 및 경고음, 각 초음파 센서 위치에 맞는 LED작동으로 사용자들에게 추돌 위험경고와 함께 장애물의 위치파악이 가능하도록 한다. 따라서 스마트 전동휠체어를 통하여 수동적인 움직임이 아닌 능동적이고, 초음파 센서로 인해 안전한 이동이 가능하게 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.162-163
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• 2023

본 논문은 휠체어 사용자들이 직면하는 안전, 이동성 자립성 등의 문제를 해소하는 것을 목적으로 하는 internet of things(IoT) 기반 스마트 휠체어를 연구하였다. 본 연구에서는 휠체어의 중요한 기능인 경사로에 따라 자동으로 기울기가 조정되는 기능을 중점적으로 개발했다. 이 기능은 사용자의 안전을 보장하며, 동시에 이동의 편의성을 증가시키는 역할을 한다.

• 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.