• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.385-390
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• 2000

The alignment of the prosthetics is very important in an amputee's gait. In the present study. a static prosthesis-alignment device was developed. It consisted of a force plate with four load cells, a laser beam controlled by a step motor, and a control part programmed by PCBASIC. Using the static prosthesis-alignment device, we measured the distance between the load line and various joints of 24 normal volunteers in three standing postures. such as neutral, forward leaning, and backward leaning. Only neutral postures were evaluated on four trans-tibial amputees. The load line for the normal person's neutral position located anterior to the ankle, the knee, and the greater trochanter, but posterior to the shoulder joint. Forward and backward leaning of the normal person resulted in a significant anterior and posterior movements of the load line, respectively. The load line for the amputated side of the trans-tibial amputee also located anterior to the ankle, the extremity prostheses, providing a good relative locations of the load line with respect to various joints.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.84-85
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• 1998

This study was conducted to characterize the gait of a person climbing or descending the stairs. Using our motion analysis system (Vicon 370), gait patterns of ten healthy females (18.8 - 19.6 yrs. old) were measured 1) when a subject tip-toed the stairs, 2) when a subject climbs the stairs with the whole foot, and 3) when a subject went down the stair, respectively. The results of each cases were compared with the data for the level walking collected from 21 healthy females in the previous studies. The stairway gait data can be used as a useful reference in the design of artificial limbs for the lower-limb amputee.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.80-81
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• 1998

In this study, an experiments and numerical simulation of a three chamber pneumatic cylinder for an intelligent AK-knee prosthesis is performed. The cylinder has a variable orifice which can be controlled automatically through a microprocessor controller as needed while amputee gaits. In the experiment, the cylinder was driven by a cam whose trajectory of simulates the normal gait and axial forces of cylinder with different of orifice opening was measured. The numerical simulations was based on thermodynamic and fluid mechanical consideration. The experimental results and the numerical results were in good agreement.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.247-249
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• 2007

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60㎐ power-line noise, amplifier, and a level circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.2
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• pp.9-14
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• 2012

In this study, an advanced knee joint for active prosthesis leg driven by a linear actuator is suggested. The structure of knee joints of existing active prosthesis legs consists of three links. This kind of linkage requires large torque to drive the active prosthesis legs. Thus a new linkage structure is suggested to solve such problem in this paper. Motion characteristics of the suggested linkage are examined in the simulation. The motion simulation results show that the proposed linkage is able to imitate human gait cycles with the half of linear actuator speed in existing linkages.

• 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.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.12
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• pp.550-557
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• 2006

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. In this paper is proposed two types of sensors with the circle- and bar-shaped reference electrode, but all input electrodes are the bar-shaped. The metal material of the electrodes is the stainless steel (SUS440) that endures sweat and wet conditions. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60Hz power-line noise, amplifiers, and a mean absolute value(MAV) circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.117-122
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• 2007

The novel implant system was developed using osseo-integration technology which enable amputee to overcome skin troubles in use of previous socket system and was evaluated in view of biomechanics, radiology, histology, and pathology. The osseo-integrated implants were designed and manufactured using CT image of canine's tibia and were applied to laboratory animals (canines). The follow-up studies were performed for 24 months with 10 canines. In radiology examination, we found that the relative low strain distribution caused medial and posterior bone resorption and then we verified them by biomechanical testing. In histological approach, the complete osseo-integration was observed through the activity of osteoblast cells around bone-implant interface and the radial outer region of bone due to peristeum reaction. Lastly in pathological aspect, the evidence of superficial infection was detected but that of deep infection was not. Therefore it is thought that infection problem will be overcome by immunity of body and good hygiene.

• Journal of Biomedical Engineering Research
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• v.26 no.4
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• pp.243-249
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• 2005

The number of people who have lost limbs due to amputation has increased due to various accidents and diseases. Numerous attempts have been made to provide these people with prosthetic devices. These devices are often controlled using myoelectric signals. Although the success of fitting myoelectric signals (EMG) for single device control is apparent, extension of this control to more than one device has been difficult. The lack of success can be attributed to inadequate multifunctional control strategies. Therefore, the objective of this study was to develop multifunctional myoelectric control strategies that can generate a number of output control signals. We demonstrated the feasibility of a neural network classification control method that could generate 12 functions using three EMG channels. The results of evaluating this control strategy suggested that the neural network pattern classification method could be a potential control method to support reliability and convenience in operation. In order to make this artificial neural network control technique a successful control scheme for each amputee who may have different conditions, more investigation of a careful selection of the number of EMG channels, pre-determined contractile motions, and feature values that are estimated from the EMG signals is needed.

• Clinical Pain
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• v.19 no.1
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• pp.28-31
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• 2020

The incidence of heterotopic ossification (HO) was reported to be higher in combat-injured patients than in civilian trauma patients. HO is often considered a possible cause of residual limbs pain in amputee. Here, we report the case of a 21-year-old male, who underwent a traumatic right transfemoral and left transtibial amputation with two segments of painful HO around his left amputation site. We report the effect of extracorporeal shock wave therapy (ESWT) on size and pain associated with HO. After ESWT, the visual analog scale score decreased from 5~6 to 0~1 and the size of two masses decreased from 13.1 × 6.7 mm and 12.5 mm to 11.9 × 4.7 mm and 12.2 mm, respectively. To the best of our knowledge, this is the first case that has reported on the treatment of HO using ESWT for a traumatic transtibial amputation patient. The case suggests that ESWT could serve as a complementary treatment for HO in traumatic amputation patient.