Papers by Author: Hyun Kyoon Lim

Abstract: With the increasing needs of the more convenient transportation, wheelchairs are often used by people with mobility disabilities and the elderly people. However, as wheelchairs are primarily designed for the mobility assistive devices, not for the vehicle seats, wheelchair users are exposed to risk factors for neck and upper body injury caused by automobile accidents. In this paper, in accordance with the ANSI/RESNA WC-19, a fixed vehicle mounted wheelchair occupant restraint system (FWORS), wheelchair integrated restraint system (WIRS), and wheelchair integrated x-bend restraint system (WIXRS) are evaluated using computer simulations for the case when a wheelchair is subjected to the frontal impact (20 g, 48 km/h).

Abstract: In this study, we assessed spasticity objectively and quantitatively using the pendulum foot drop test. Twenty-eight patients with spasticity and ten healthy subjects participated in the study. A newly designed table for the motion analysis system using infrared cameras and a foot release mechanism were used. Electromyograph (EMG) was recorded from eight muscles of the lower limb during a foot drop maneuver. The study investigators suggest ‘modified relaxation index’ as a good representative parameter for describing spasticity. This parameter is based on quantitative measurement rather than investigator discretion, as in the modified Ashworth scale (MAS).

Abstract: AFO is a device, which is usually recommended for hemiplegics to help their pathologic gait. To date, no good engineering guidance is available. We analyze mechanical characteristics of AFO and evaluate structural stability effect of thickness of ankle foot orthosis (AFO). The study is to provide a guidance to make a functional AFO. Basic material characteristics such as Young’s modulus and Possion’s ratio were measured through material tests. Finite element models were made and analyzed based on various shapes and gait analysis. Young’s modulus of polypropylene is 1.15 GPa and Possion’s ratio is 0.35. Rigidity of AFO is more affected by the ankle width than the thickness of ankle area. The strain calculated by finite element analysis (FEA) in the neck area is twice as much as experimental results but the both of their trend show similar pattern. AFO was studied through its structural and functional analysis. Experimental structural analysis and FEA were made and compared.