• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.771-782
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• 2017

This paper describes the development of a wearable robot to assist ankle power for the elderly. Previously developed wearable robots have generally used motors and gears to assist muscle power during walking. However, the combination of motor and reduction gear is heavy and has limitations on the simultaneous control of stiffness and torque due to the friction of the gear reducer unlike human muscles. Therefore, in this study, Mckibben pneumatic muscle, which is lighter, safer, and more powerful than an electric motor with gear, was used to assist ankle joint. Antagonistic actuation using a pair of pneumatic muscles assisted the power of the soleus muscles and tibialis anterior muscles used for the pitching motion of the ankle joint, and the model parameters of the antagonistic actuator were experimentally derived using a muscle test platform. To recognize the wearer's walking intention, foot load and ankle torque were calculated by measuring the pressure and the center of pressure of the foot using force and linear displacement sensors, and the stiffness and the torque of the pneumatic muscle joint were then controlled by the calculated ankle torque and foot load. Finally, the performance of the developed ankle power assistive robot was experimentally verified by measuring EMG signals during walking experiments on a treadmill.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.7-13
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• 2009

Recently, the interest on walking assistances in order to assist aged people has increased due to the increase of the aged. However, most walking aid systems have a weakness for a slope because they don't have power. So, they have a weak point which makes users difficult to move when they are weak in the legs. That is why the interest on walking assistances with power has increased. The use of the walking aid systems should be easy because most users are old people. Thus, we produce module to grasp walking intent of users by using various sensors such as potentiometer, FSR(Force Sensing Resistance) Sensor and Stretch Sensor and calculate the response time to the module. Firstly, the response time of handlebar which is a kind of potentiometer is 420ms and Resilience of it is 140ms. Secondly, the response time of handlebar which use FSR Sensor is 320ms and Resilience of it is 220ms. Finally, the response time of the Stretch Sensor is 160ms and Resilience of it is 140ms. The performance of Stretch Sensor is the best among the three kind of sensors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.420-426
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• 2020

In this study, an assistive device for BVM (Bag Valve Mask) was developed. When emergencies occur, rescuers must perform artificial respiration within four minutes utilizing suitable BVM. If not, the patient can suffer serious damage within their brain and body systems. The rescuer must execute artificial respiration until the patient arrives at the hospital. In the process of artificial respiration, the rescuer can feel fatigued in their forearm muscles, particularly those who may have smaller hands or weaker muscle strength. Many products have been developed to solve these problems, but these products are difficult to market and commercialize because of their volume, size, and difficulty of use. In this paper, the BVM assistive device that has been previously manufactured was improved, and an attempt was made to devise a new method that reduces the burden on the user. The BVM assistive device can be divided into three-parts: a head part for compressing the air bag, which can control the amount of air; the body part for coupling with BVM; and finally, the handle that can rotate for better use on various postures of patients. Throughout the experiment, the assistive device could inject an equal amount of air into the patients. As a result, the rescuer could feel less fatigue and inject a suitable amount of air to emergency patients during artificial respiration.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.1
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• pp.51-56
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• 2003

The main goal of existing mobile robot system was a complete autonomous navigation and the vision information was just used as an assistant way such as monitoring For this reason, the researches have been going towards sophistication of autonomousness gradually and the production costs also has been risen. However, it is also important to control remotely an inexpensive mobile robot system which has no intelligence at all. Such systems may be much more effective than fully autonomous systems in practice. Visual information from a simple camera and distance information from ultrasonic sensors are used for this system. Collision avoidance becomes the most important problem for this system. In this paper, we developed a force feedback joystick to control the robot system remotely with collision avoiding capability. Fuzzy logic is used for the algorithm in order to implement the expert s knowledge intelligently. Some experimental results show the force feedback joystick werks very well.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.449-458
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• 2001

This is a test report of system efficiency for the moving-actuator type Bi-ventricular assist device (AnyHear $t^{MT}$ ) Seoul National University). $AnyHeart^{TM}$), as an energy converter. utilities a brushless DC motor(S/M 566-26A. Sierracin/ Magnedyne, Carlsbad, CA. U.S.A.) generating their pendulous motion in the epicyclic gear train. It is necessary to know about the overall efficiency of the system. The system is subdivided into three parts: motor part, actuator part and blood sac part (including valves, etc.) according to system mechanism. The motor was operated with a variable range of torque. angular speed and width of voltage Pulse In this report. $AnyHeart^{TM}$ is focused on the efficiency of the motor and actuator parts. 4 $\ell/min$ pump output. which is normal condition of $AnyHeart^{TM}$ system, the total system efficiency is 8%, which is composed of 50%, 85% and 17% efficiency (motor Part, actuator Part and blood sac Part) respectively. In the analyzed result. applied input voltage on normal condition of $AnyHeart^{TM}$ is determined. Also speed Profile with considering filling state of blood sac is Provided. In the test of the in vitro mock circulation. some experimental results are Provided to demonstrate the effectiveness of the Presented approach.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.208-213
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• 2006

경사진 안창은 안창의 경사로 발의 자세를 교정함으로써 하지 통증을 완화시키는 데 사용되는 보조치료기구로 내측 경사진 안창(MWI: medially wedged insole)과 외측 경사진 안창(LWI: laterlly wedged insole)으로 나뉜다. 본 연구는 내/외측 경사진 안창이 족부압력에 미치는 영향을 정량적으로 분석하고자 한다. 분석변수는 압력중심(COP: center of pressure)의 궤적 변화, 발바닥 내 세 개 구획에 상대적으로 작용하는 수직 힘(RVF: relative vertical force) 그리고 여덟 개 해부학적 지점의 압력이다. 경사진 안창의 경사조건은 내/외측 각각 $5^{\circ},\;8^{\circ},\;15^{\circ}$이며, 경사가 없는 안창을 포함해 총 일곱 가지 안창이 실험에 사용되었다. 실험참여자로는 20대 성인 남성 10명이 참여하였다. 실험결과 앞발 누름기에서 MWI와 LWI는 모두 COP를 내측으로 이동시키고 외측 압력을 감소시켰다. 뒤축 접지기에서 MWI는 COP를 내측으로 이동 시키고 내측압력을 증가시키는 반면, LWI는 COP를 외측으로 이동시키고 외측압력을 증가시켰다. 그리고 RVF 분석결과 MWI와 LWI는 모두 앞발 부위 힘의 크기를 감소시켰고, LWI만이 발 뒤축 부위 힘의 크기를 증가시켰다.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.611-613
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• 2011

본 논문에서는 P.B.D 장비의 리더 하부에 연결 할 수 있는 보조 압입 장치를 개발하였다. 이를 통해 기존의 타설 보다 강한 힘으로 플라스틱 보드를 삽입 할 수 있게 되어 작업의 질적인 향상과 작업 시간을 단축 하였으며 와이어의 절단을 미연에 방지 할 수 있게 되었다. 또한 와이어의 수명을 연장시켜 경제적인 효과를 가져올 수 있었다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.106-108
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• 2003

최근 들어 인터넷의 급속한 발전으로 사용자가 처리해야할 점보의 양이 급속히 늘어나게 됨으로써 사람이 혼자만의 힘으로 이 많은 정보를 처리하는 것이 하나의 고단한 작업이 되었고, 이 작업을 돕기 위한 소프트웨어 에이전트(software agent) 의 필요성이 대두되었다. 본 논문에서는 구현한 소프트웨어 에이전트가 사용자의 업무보조 (personal assistant) 라는 자신의 임무를 수행하기 위하여 온톨로지(ontology)를 기반으로 사용자의 선호도(preference) 와 의사결정 패턴을 학습하여 사용자 프로파일(user Profile) 을 작성한다. 학습한 프로파일을 바탕으로 사용자의 선호도와 일치하는 제품을 추천하는 지능형 에이전트를 제안하고. 실질적인 실험을 통해 학습된 사용자의 성향을 분석한다.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.837-848
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• 2014

This paper describes the development of a walking assistive robot for effective self-rehabilitation for elderly people facing an inconvenience in walking. The main features of the developed robot are enhanced safety and mobility using the baby walker and electric wheelchair mechanisms and an accurate walking tracking control algorithm using potentiometers and stereo cameras. Specifically, a pelvis supporter is designed to prevent the user from falling down and reduce the burden on their legs, and electric motors are used for easy locomotion with low effort. Next, the walking intention and direction of the user are automatically recognized by using potentiometers attached at the pelvis supporter so that the robot can track the user, and the rapidity and accuracy of the tracking were increased by applying a lower-body motion analysis algorithm with stereo cameras. Finally, the user-tracking performance of the developed robot was experimentally verified through stepwise walking assistance experiments.