• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.2
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• pp.147-153
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• 2016

The aims of this study were to evaluate the joint coordination between hip and knee joints in the transfemoral amputees, and its symmetry between sound and prosthetic limbs. Seven transfemoral amputees ($46.4{\pm}10.7-year-old$, $174.8{\pm}3.5cm$, $78.3{\pm}9.7kg$) and 7 able bodies ($24.0{\pm}4.5-year-old$, $174.5{\pm}5.9cm$, $66.9{\pm}9.4Kg$) participated in this study. They walked at a self-selected walking speed across a 10m level ground. Simultaneously angle and angular velocity in the hip and knee joint were measured by motion analysis system. Then continuos relative phase(CRP), standard deviations of CRP (CRP_SD) and symmetry index(SI) were calculated. In able bodies, there were no differences of the parameters between left and right limb(all p>0.05). However, significant differences between sound and prosthetic limb in most of the parameters, except for CRP for stance phase were shown (all p<0.05). There were differences in all SI between transfemoral amputees and able bodies (p<0.05). In conclusion, joint coordination was altered in transfemoral amputee during level walking and shown in interlimb asymmetry.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.305-313
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• 2016

Movements of the lower limb are important for normal walking and smooth oscillation of the center of gravity. The ankle rotations such as dorsi-flexion, plantar-flexion, inversion and eversion allows the foot to accommodate to ground during level ground walking. Current below knee (B/K) prostheses are used for replacing amputated ankle, and make it possible for amputees to walk again. However, most of amputees with B/K prostheses often experience a loss of terrain adaptability as well as stability because of limited ankle rotation. This study is focused on the development of multi-rotational prosthetic foot for lower limb amputee. Our prosthesis is possible for amputees to easily walk in level ground by rotating ankle joint in sagittal plane and adapt to the abnormal terrain with ankle rotation in coronal plane. The resistance of ankle joint in the direction of dorsi/plantar-flexion can be manually regulated by hydraulic damper with controllable nozzle. Furthermore, double layered rubber induce the prosthesis adapt to irregular ground by tilting itself in direction of eversion and inversion. The experimental results highlights the potential that our prosthesis induce a normal gait for below knee amputee.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.403-416
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• 1998

Socket pressure distributions with gait analysis of a trnsfemoral and a transtibial prostheses were measured in order to assess an optimal socket fitting and function. Ankle joint was aligned by the neutral and the dorsi/plantar flexed positions. Compared to dorsi and plantar flexed positions of ankle joint, cadence and walking speed increased with the neutral ankle joint alignment. Other gait parameters were close to the normative data with the neutral ankle joint alignment. For the transfemoral amputee, dorsiflexed alignment of the ankle joint created high pressure on the lateral aspect of the socket, on the other hand, plantarflexed alignment resulted in increased pressure on the medial aspect of the socket. For the transtibial amputee, dorsiflexed alignment of the ankle resulted in high pressure on the antero-lateral aspect of the socket during mid-stance, but apltarflexion of the ankle joint showed slight increases in pressure at the same location in the socket. The present study clearly demonstarted that malalignment of a prosthesis results in localized increasesing pressure within the socket. Proper slignment of the prosthesis is required in order to acquire an appropriate socket-limb interface as well as the proper gait.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1391-1392
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1009-1010
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• 2009

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.281-284
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• 2002

대부분의 보조기 및 의족은 기계식이 주류이며 환자가 착용시 정상보행은 부드럽지 못하고 원활한 보행을 위해서는 장기간 동안 훈련이 요구된다. 따라서 대퇴의족에서 발생하는 이러한 문제점을 개선하기 위해 본 연구에서는 대퇴절단자(transfermoral amputee)의 보행을 정상보행에 일치하는 보행 능력을 복원하기 위해 근전도 신호와 인공신경망을 이용하여 적응 PID제어기를 설계하였고 그 제어 결과를 제시하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1587-1588
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• 2011

• Fashion & Textile Research Journal
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• v.11 no.4
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• pp.621-632
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• 2009

The purpose of this study was to analyze the physical characteristic of the wheelchair users by directly measuring the disabled men who use a wheelchair and to classify body types. The subjects were 178 male wheelchair users 20-69 years range of age. The results of this study were as follows. The cause of disability was classified into four groups; Poliomyelitis(P), Spinal Cord Injury(S), Cerebral Palsy(C), Amputee(A). There was a remarkable difference in the physical characteristic of the wheelchair users due to their cause of disability. A have greater values in all the dimensions. P have the largest drop values and smaller values in the lower body dimensions. S have greater values in the height of upper body trunk, back interscye length, and chest circumference, whereas smaller values in waist front length and thigh circumference. C have smaller values in most body dimensions except circumference of lower limb. By the factor analysis on the anthropometric data came out the result to be eight factors. The result of cluster analysis using factor scores shows the body types of wheelchair users can be divided into four body types; PY, RBB, TBP, RA. PY type is short and has the largest drop values, whereas RBB type tends to have the smallest drop values. TBP type is tall and the torso tends to be larger than those of the other types. RA type has smaller values in front body dimensions and moderate values in other dimensions. The diversity in body types should be considered among the wheelchair users.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.613-624
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• 2000

In this study, new design method of prosthetic foot was suggested which can evaluate the performance of prosthetic foot by implementing amputee's gait simulation using the finite element analysis. The basic shape of ESPF(Energy Storing Prosthetic Foot) was designed which is suitable for the below-knee amputee considering mechanical properties and kinematic properties. And, the performance evaluations were performed using the Taguchi method with orthogonal array L25. As a result, average main effect of factors for the ESPF's performance were calculated and then optimum condition of given shape was selected. Essential particulars for the performance evaluation from the simulation result were the quantity of external work needed in stance phase, the quantity of transferred energy from the ESPF through the knee, and the vertical displacement of knee at toe-off. Reasonable optimum condition was obtained from the using performance index. From this study, it was found that it is necessary for the design of ESPF to consider the geometrical data related to the magnitude of load on elastic material.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.769-776
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• 2013

The dynamic compliance characteristics of a prosthetic foot midgait are very important for natural performance in an amputee's gait and should be in a range that provides natural, stable walking. In this study, finite element analysis (FEA) and classical laminate theory were used to examine the mechanical characteristics of a carbon-epoxy composite laminate prosthetic foot as a function of variation in the lamination composition. From this analysis, an FEM model of a prosthetic keel, made from the composite material, was developed. The lamination composition of the keel was designed for improved stiffness. The prototype product was fabricated using an autoclave. Vertical loading response tests were performed to verify the simulation model. The results of the experiments were similar to those from simulations below the loading level of the gait, suggesting use of the proposed simulation model for prosthetic keel design.