• Journal of the Korean Society for Precision Engineering
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• v.31 no.10
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• pp.913-922
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• 2014

This paper describes design of a robotic above-knee prosthetic leg which is powered by electrical motors. As a special feature, the robotic prosthetic leg has enough D.O.F.s. For mimicking the human leg, the robotic prosthetic leg is composed of five joints. Three of them are called 'active joint' which is driven by electrical motors. They are placed at the knee-pitch-axis, the ankle-pitch-axis, and the an! kle-roll-axis. Every 'active joint' has enough torque capacity to overcome ground reaction forces for walking and is backlashless for accurate motion generation and high-performance balance control. Other two joints are called 'passive joint' which is activating by torsion spring. They are placed at the toe part and designed by Crank-rocker mechanism using kinematic design approach. In order to verify working performance of the robotic prosthetic leg, we designed a gait trajectory through motion capture technique and experimentally applied it to the robot.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.131-142
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• 2005

This study was investigated the stability of the AK amputee gait through analysing the variability on kinematic variables between the sound leg and the prosthetic limb. The one male, AK amputee who could walk for himself with his prosthetic limb was participated in this study. Six cameras of the MCU 240 and the QTM(Qualisys Track Manager) software were used for data collecting in this study. The relative angle of both segments was the difference between the absolute angle of the distal segment and the absolute angle of the proximal segment. The coupling angles between the prosthetic limb and the sound leg were caculated on the thigh Flexion/Extension in relative to the shank Flexion/Extension and the shank Flexion/Extension n relative to the foot Flexion/Extension. In order to evaluate the variability of segment and joint angle, C.V. was used, and to evaluate the variability for coupling angles, the Relative motion calculated by vector coding method of the continuous methods was used. As stated, the gait pattern of the prosthetic limb was almost similar gait pattern of the sound leg, but the prosthetic limb showed that the gait pattern of the sound leg and the prosthetic limb were not stable against the sound leg.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.2
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• pp.165-171
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• 2016

A prosthetic knee for above-knee (AK) amputee is categorized into passive and active type. The passive prosthetic knee is generally made by elastic material. Although AK amputee can easily walk by using passive prosthetic leg, knee joint motions are not similar to ordinary persons. The active prosthetic leg can control the knee angle owing to the actuator and microprocessor. However, the active type is not cost-effective and the stability may be lost due to the malfunction of sensors. In order to resolve these disadvantages of passive and active type, a semi-active prosthetic knee which can control the knee angle is proposed in this work. The proposed semi-active one requires a less input energy but provides active type performance. In order to achieve this goal, in this work, a semi-active prosthetic knee using magneto-rheological (MR) damper for AK amputees is designed. The MR damper can support the weight of body by using less energy than actuator of active prosthetic. It can control knee angle by inducing the magnetic field at the time of stance phase. This salient characteristic is evaluated and presented in this work.

• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.159-168
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• 2024

Lower limb amputees are increasing due to various reasons. It is difficult for lower limb amputees to walk without an assistive device such as a prosthetic leg. In this paper, an electronically controlled knee-type prosthetic leg with a 4-bar linkage structure for lower limb amputees was developed. The knee-type prosthetic leg has a 4-bar linkage structure and assists walking by using an integrated drive module. The torque is 90 Nm, the rotation speed is up to 120 deg, and it weight 1.9 kg, so it is lighter than a commercial prosthetic leg, so it can be used for a long time because there is less fatigue when walking. An integrated control board was developed by applying various sensors and microprocessor. The motor drive and encoder are built into the integrated drive module. The integrated control board and integrated drive module communicate using CAN. When a lower limb amputee wears a knee-type prosthetic leg and walks, it shows a shape similar to the swing phase graph of a normal people, and it is possible to walk naturally while walking.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1505-1508
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• 2008

One of the important functions of prosthetic foot is the foot inversion-eversion which is so important when walking on uneven surfaces. The aim of our study was to evaluate the effect of foot eversion angle especially on knee and ankle joint for transtibial amputees by motion analysis. The experimental data were collected from three transtibial amputees and then ten healthy individuals. To simulate walking on side sloping ground, we used custom-made slope (5, 10, 15 degrees). Motion analysis was performed by 3-dimensional motion analyzer for 6 dynamic prosthetic feet. The results showed that knee abduction moments of amputated leg were decreased but those of sound leg were mainly increased as foot eversion angle increased. And ankle abduction moments of sound leg were inconsistent in magnitude and tendency between control and experimental group. Therefore foot eversioncharacteristics should be considered to develop advanced prosthetic foot.

• Korean Journal of Applied Biomechanics
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• v.23 no.1
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• pp.77-83
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• 2013

The purpose of this study was to compare kinematic variables and stiffnesses of ankle joints between normal person and transfemoral amputee gait in order to develop or fit prosthetic leg. Twenty subjects (ten normal persons and ten transfemoral amputees) participated in this experiment, and walked three trials at a self-selected pace. The gait motions were captured with Vicon system and variables were calculated with Visual-3D. The velocity, stride length, stride width, cycle time, double limb support time and right swing time of gaits were statistically significant. Because coefficients of variability of normal persons on velocity, double limb support time and swing time were greater than transfemoral amputees, normal persons controlled these gait variables effectively. The stiffnesses of ankle joints were not statistically significant, but patterns of stiffnesses of ankle joints during three rockers were absolutely different. The negative correlations between stiffnesses of ankle joints and cycle time and swing time were presented. These differences suggest that developing and fitting prosthetic leg were demanded. Further studies should develop fitting program and simulator of prosthetic leg.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.886-891
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• 2009

One of the important functions of prosthetic foot is the foot inversion-eversion which is so important when walking on uneven surfaces. The aim of our study was to evaluate the effect of foot eversion angle especially on knee and ankle joint for transtibial amputees by motion analysis. The experimental data were collected from three transtibial amputees and then ten healthy individuals. To simulate walking on side sloping ground, we used custom-made slope (5, 10, 15 degrees). Motion analysis was performed by 3-dimensional motion analyzer for 6 dynamic prosthetic feet. The results showed that knee abduction moments of amputated leg were decreased but those of sound leg were mainly increased as foot eversion angle increased. And ankle abduction moments of sound leg were inconsistent in magnitude and tendency between control and experimental group. Therefore foot eversioncharacteristics should be considered to develop advanced prosthetic foot.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.36-42
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• 2000

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.3
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• pp.110-117
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• 2018

The development of prosthetic hand or prosthetic leg equipment is steadily taking place globally. Though it would be difficult to create or feel the same way as a human hand, it would be a great for the amputated person if they can pick things up or do some movement as they want. It has become possible to develop low-cost prosthetic hand according to development of 3D printing technology. If people can develop personalized prosthetic equipment at similar prices to meet this trend, the utilization and penetration rate will be much higher. In this study, it describes how to develop a user-customizable prosthetic hand using 3D printing. To do this, the transformational parameters of prosthetic hand shape modeling are extracted as variability values, and the functions for controlling prosthetic hand motion are designed as software design patterns. This allows people who need a prosthetic hand to have their own prosthetic hand at a fast and affordable price.

• Journal of IKEEE
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• v.26 no.2
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• pp.249-256
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• 2022

The prosthetic leg is a device that performs walking instead of a amputated lower limb, and require a change in locomotion mode by providing the user's intention to respond to a discontinuous locomotion environment. Research has been conducted to detect the users' intentions through biomechanical features inside the socket that directly contacts the cut site in demand for natural locomotion mode changes without external control equipment. However, there is still a need for a sensor system that is suitable for the internal environment of the main body and socket of the cut site. Accordingly, this paper proposed a film-type sensor system that is suitable for the main body characteristics of the cut site, is not affected by the temperature and humidity conditions inside the socket, and is easy to manufacture in various sizes. The proposed sensor is manufactured base on Velostat film and takes into account the pressure measurement characteristics that vary with size. Through the experiment, the change in the internal pressure of the socket due to the intentional posture performance of the wearer was measured, and the possibility of detecting the intention to change the locomotion mode was confirmed.