• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.957-962
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• 2005

Today, the elderly is increasing gradually in the Republic of Korea society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. We are establishing a new field of healthcare engineering for elderly people and aiming to support for aged people and disabled people using adaptive control and instrument technology. In this paper, the goal is to implement the shared control of a robot mobility aid for the elderly. As using this type of assistive technology to be useful by its intended user community, it supports elderly people and handicapped people to live independently in their private homes. The interface transforms the force applied by the user into the robot's motion. Devices like buttons, joysticks, and levers already exist for relaying user input; however, they require hand displacement that would loosen or otherwise release the user's hold. Such interfaces make operation very difficult and potentially unsafe. Therefore, we propose a shared control system. It's safe more than joysticks and buttons. The shared control is a means of registering the user's intention through physical interaction. It's an important component in the development of robotic elderly assistant. The concept of shared control describes a system which is two or more independent control systems. We are using that the three component blocks consist of pressure sensor (flexible force sensor), circuit of measurement and transfer function. Experimental trials of this paper have been tested at the indoor environment. The robot is able to know the user intended direction through haptic device were logged along with the robot's force sensor.

• Physical Therapy Korea
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• v.24 no.4
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• pp.54-59
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• 2017

Background: Light touch cue is a sensory input that could potentially help in the control of posture. The immediate stimulatory effect of light touch cues using a cane during gait is associated with postural stability. This strategy can help post-stroke individuals regain their ability to perform the sit-to-stand (STS) transfer safely. Objects: The effects of light grip on postural control during the STS transfer in post-stroke subjects were investigated. Methods: Eleven participants (6 men, 5 women) with hemiplegia due to stroke were recruited in the study. The subjects with hemiparesis performed STS transfer in three randomly assigned conditions (1) without a cane (2) light grip with a cane (3) strong grip with a cane. Results: The difference in weight-bearing distribution between the left and right feet, when the subjects were instructed to stand up, was $52.73{\pm}2.13%$ without a cane, $42.75{\pm}3.26%$ with a strong grip, and $43.00{\pm}2.55%$ with a light grip (p<.05). The rate of rise in force indicates the peak power provided by subjects during their STS transfers. The rate of rise in force was statistically significantly lower without a cane than that with a light grip or a strong grip (p<.05). The subjects' centers of pressure sway on the mediolateral side during STS transfers statistically significantly declined with a light grip or a strong grip when compared to those without a cane (p<.05). Conclusion: When the subjects with hemiparesis used a cane during STS transfers, their duration, center of pressure sway, and difference in weight-bearing distribution were all reduced. The subjects also exhibited similar results during STS transfers with a cane gripped lightly. This result may provide guidelines for the use of assistive devices when patients with hemiparesis practice STS transfers in clinical settings.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.407-422
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• 2014

Objective: The purpose of the study is to develop quantitative usability evaluation criteria for senior-friendly autonomous transportation robot. Background: The Republic of Korea has become the most rapidly aging society, and is anticipated to enter the post-aged society in 2026. To raise the quality of life of a senior with limited mobility and to reduce the burden of caregivers, many high-tech assistive products with information technologies are developed nowadays. The senior-friendly autonomous transportation robot is one person robot vehicle to move a senior to the destination for hospitals, nursing homes or silver town complex. With built-in navigation system and environmental monitoring censors, it automatically seeks the path to the destination and avoids collision to obstacles and pedestrians on the way. Due to the early stage of the product, few usability studies in this field have been done, mostly on general service robots to assist seniors, power wheelchairs and delivery robots. ISO and KS standards for the service robots are focused on safety. Method: Based on the reference usability index, the early draft of the usability evaluation questionnaires was developed. After small group tests and interviews, the experts modified the initial draft to the Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot (UEC-SFATR). Result: UEC-SFATR consisted of 4 subscales - Safety, Controllability, Efficiency and Satisfaction. All of the 4 subscales of UEC-SFATR were passed the reliability criteria by 4 groups of seniors, divided by gender and familiarity of smart-devices. Conclusion: UEC-SFATR covers wider area of user experiences of the SFATR and is a good measurement tool to help both the users and developers of the robot. Application: This study provides guide to the future product development and product competitiveness evaluation by quantifying user experiences for the SFATR.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.1
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• pp.59-69
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• 2011

Purpose : The purposes of this study were to find correlations among Fugl-Meyer Assessment Scale, walking velocity, walking asymmetry and balance ability. Methods : The study sample consisted of 50 stroke patients referred to the Department of Rehabilitation Medicine in the Sanggye Paik, Ilsan Paik, Seoul Paik, and Dobong Hospital. All subjects were ambulatory with or without an assistive device. All participants were assessed on Fugl-Meyer Assessment scale and walking velocity, walking asymmetry. The data were analyzed using independent t-test, ANOVA, and multiple regression. Results : The results revealed that upper extremity coordination, balance and pain items of Fugl-Meyer Assessment scale were significantly correlated with walking velocity and upper extremity and upper extremity motor and balance items of Fugl-Meyer Assessment scale were significantly correlated with walking asymmetry. Fugl-Meyer Assessment scale was not significantly correlated with Static Balance Index, Dynamic Balance Index and Weight Distribution Asymmetry Index. Their power of explanation regarding comfortable walking velocity and comfortable walking asymmetry were 60.3%, 42.5% respectively. Conclusion : These results showed that Fugl-Meyer Assessment scale is significantly correlated with walking velocity, asymmetry and not significantly correlated with balance ability. Therefore Fugl-Meyer Assessment scale is an appropriate assessment tool to predict walking ability of patients with stroke. Futher study about walking velocity and asymmetry by change of Fugl-Meyer Assessment scale is needed using a longitudinal study design.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2006-2013
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• 2015

Deaf are it is difficult to communicate to represent the voice heard, so theay use mostly using the speech, sign language, writing, etc. to communicate. It is the best way to use sign language, in order to communicate deaf and normal people each other. But they must understand to use sign language. In this paper, we designed and implementated finger language translation system to support communicate between deaf and normal people. We used leap motion as input device that can track finger and hand gesture. We used raspberry pi that is low power sing board computer to process input data and translate finger language. We implemented application used Node.js and MongoDB. The client application complied with HTML5 so that can be support any smart device with web browser.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.617-624
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• 2015

This paper describes the development of a wearable robot to assist the elbow muscle for use by elderly workers in aging societies. Various previously developed wearable robots have drawbacks in terms of their price, portability, and slow recognition of the wearer's intention. In this paper, emphasis is placed on the following features to minimize these drawbacks. The first feature is that an actuator is attached only at the elbow joint that withstands the highest moment during arm motion to reduce the weight, volume, and price of the robot and increase its practicality. The second is that operation of the wearable robot is divided into two modes, a tracking mode and a muscle strengthening mode, and the robot can automatically switch between these modes by analyzing the wearer's intention through the brachial muscle strength measuring device developed in this study. The assistive performance of the developed wearable robot is experimentally verified by motion tracking experiments without an external load and muscle strengthening experiments with an external load. During the muscle strengthening experiments, the power of the muscle of the upper arm is measured by a commercial electromyography (EMG) sensor. Motion tracking performance at a speed of $120^{\circ}/s$ and muscle assistance of over 60 % were obtained using our robot.

• Journal of Trauma and Injury
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• v.23 no.2
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• pp.163-169
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• 2010

Purpose: Spinal epidural hematoma (EDH) is a rare condition requiring an urgent diagnosis and management. We describe here the clinical features, magnetic resonance image (MRI) findings, and outcomes of surgery in six patients with spinal EDH. Methods: We retrospectively analyzed six patients who underwent surgery for spinal EDH between April 2004 and May 2010. Preoperative MRI findings within 48 hours of symptom occurrence were analyzed for cord compression, extent of EDH, and presence of vascular abnormalities. Pre- and postoperative neurological status was also assessed comparatively. Results: Our six patients consisted of three men and three women, with a mean age of 70 years (range: 54-88 years), who presented with the back pain or motor weakness. The mean follow-up period was 34 months (range: 2-72 months). Two patients had cardiovascular disease and were taking warfarin, but the others had no history of medical comorbidity. Those two patients taking warfarin had a history of trauma, another one experienced symptoms during a strenuous effort, and the others developed spontaneously. Before surgery, motor power was grade III in three patients, grade 0 in two patients, and normal in one patient. Preoperative MRI showed no vascular abnormalities except for the EDH in any patient. At the last follow-up, all those five patients with motor weakness showed neurological improvement compared to their preoperative status. There were no complications related to surgery. All six patients were able to ambulate with or without an assistive device. Conclusion: Spinal EDH can occur in patients without trauma, bleeding diathesis, or combined vascular pathology. The surgical outcomes of spinal EDH seem to be satisfactory, even in quadriplegic patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.12
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• pp.1067-1076
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• 2016

This paper describes the development of a hybrid-powered wheelchair (HPW) for the elderly. The proposed HPW has novel mechanical and control features compared with conventional powered wheelchairs. An ergonomic back-braking mechanism was designed in order to stop the wheels easily. In terms of control features, the HPW remarkably reduces the muscle power required by combining various assistive functions, such as wheel torque assistance, friction/inertia compensation, gravity compensation, and the one-hand driving algorithm. For wheel torque assistance, strain gauges were attached to the hand-rim in order to measure the wheel torque applied by a human. Gyroscopes and an accelerometer were attached to the wheel and chair respectively for friction and inertia compensation. An inclinometer was attached for gravity compensation and the one-hand driving algorithm was included for patients who can only use one hand. The one-hand driving algorithm controls the angular velocity of the uncontrolled wheel by using a gyroscope and pressure sensors attached to the bottom of the seat. Finally, the performance of the proposed motion assisted algorithm was verified through various experiments.