• 대한골관절종양학회지
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• 제3권1호
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• pp.18-25
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• 1997

Prosthetic replacement is one of the most common methods of reconstruction after resection of malignant tumor around the knee. Gait analysis provides a relative objective data about the gait function of patients with prosthesis. The purpose of this study was to compare the gait pattern of the patients who underwent limb salvage surgery with prosthesis for distal femur and that of patients with prosthesis for proximal tibia. This study included ten patients (4 males, 6 females, mean age 22.7 years, range 14-36) who underwent a wide resection and Kotz hinged modular reconstruction prosthesis replacement and six normal adult(Control). The site of bone tumor was the distal femur (Group 1) in six patients and proximal tibia (Group 2) in 4 patients. The follow-up period ranged from 15 to 82 months (mean : 33 months). The evaluation consisted of clinical assessment, radiographic assessment, gait analysis using VICON 370 Motion Analysis System. The gait analysis included the linear parameters such as, walking velocity, cadence, step length, stride length, stance time, swing time, single support and double support time and the three-dimensional kinematics (joint rotation angle, velocity of joint rotation) of ankle, knee, hip and pelvis in sagittal, coronal and transverse plane. For the kinetic evaluation, the moment of force (unit: Nm/kg) and power (unit: Watt/kg) of ankle, knee and hip joint in sagittal, coronal and transverse plane. In the linear parameters, cadence, velocity, step time and single support were decreased in both group 1 and group 2 compared with control. Double support decreased in group 2 compared with control significantly(p<.05). In contrast to our hypothesis, there was no significant difference between group 1 and group 2. In Kinematics, we observed significant difference (p<.05) of decreased knee flexion in loading response (G2

• 전력전자학회논문지
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• 제12권3호
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• pp.248-257
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• 2007

본 논문은 사람의 근육에서 발생하는 근전위 신호를 사용하여 2 자유도를 갖는 전동의수를 구동하기 위한 제어시스템을 제안한다. 근전위 신호를 측정하기 위한 표면 근전위 센서는 근전위 신호의 출력 특성을 이용하여 근전위 센서의 입력부와 회로부를 설계한다. 제어시스템은 전동의수를 구동하기 위하여 두 개의 제어기와 전동의수의 파지력을 측정하기 위한 파지력 센서와 파지한 물체의 미끌림을 감지하기 위한 미끌림 센서로 구성되어 있다. 가상의 근전위 신호를 이용한 실험과 정상인의 실험을 통하여 제안된 제어시스템의 신뢰성을 검증하였다.

• 대한치과보철학회지
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• 제36권4호
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• pp.587-597
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• 1998

In this study, the Periotest value was measured with Periotest to evaluate precision fit of the 2-unit and 3-unit implant-supported prosthesis by modifying the size and location of ill-fitted conditions. The 2-unit prosthesis was fabricated with the right implant fitted incorrectly and the 3-unit prosthesis with the right and center implant fitted incorrectly. To evaluate the effects of the ill-fitted sizes, 4 groups were divided.:The control group being the accurately fabricated sample group fitted properly. Group 1 was constructed with $40{\mu}m$ ill-fitted conditions, group 2 with $70{\mu}m$ and group 3 with $100{\mu}m$ ill-fitted conditions. The Periotest value was measured at each implant site after tightening 10Ncm. The result was follows : 1. The PTV on the ill-fitted area in the 2-unit implant-supported prosthesis increased as the ill-fitted conditions increased. There was a statistically significant difference among groups(p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated a statistically significant difference (p<0.05) 2. The PTV on the ill-fitted area of the 3-unit implant-supported with an ill-fitted condition in the right implant increased as the ill-fitted conditions increased. There was a significant difference among groups (p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated a statistically significant difference (p<0.05). 3. In the 3-unit implant-supported prosthesis with ill fitting conditions in the center implant, the PTV on the ill-fitted area demonstrated a statistically significant difference between the control group, group 1 and group 2 (p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated significant difference between the gap side and the adjacent side with over $70{\mu}m$ ill-fitted conditions (p<0.05). The results suggest that Periotest is a valuable objective method for evaluating the precision fit of an implant superstructure.

• 전기전자학회논문지
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• 제23권3호
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• pp.883-892
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• 2019

본 연구에서는 지능형 대퇴 의족의 노면 적응 기술 구현시 보행 환경이 변화하는 구간 및 약 경사로 보행에서의 보행 불평형 문제를 해결하기 위한 방법으로 발목 관절 운동을 제어 가능한 하퇴 의족을 적용하였다. 제안한 태퇴 의족의 개발을 위해서는 보행의 단계 구분이 필수적이다. 이러한 보행의 입각기의 단계별 구분과 유각기의 판단을 위하여 대퇴의족의 슬관절 데이터와 관성센서 데이터를 바탕으로 의사 결정 나무 학습법과 랜덤포레스트 기법을 융합한 머신러닝 기술을 제안 및 적용하였다. 이러한 방법으로 발목의 운동 상태를 제어 하였으며 보행 평형이 문제가 해소 되는지를 butterfly diagram을 측정하여 평가 하였다.

• 대한치과보철학회지
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• 제59권1호
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• pp.126-133
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• 2021

여러 연구에서 임플란트 지지 보철물의 수직 침하에 대해 보고되고 있지만, 구강내 임플란트 지지보철물의 기능 시 수직침하 양상에 대해서는 알려진 바 없다. 본 증례에서는 2명의 환자에서 구치부 단일 치아 임플란트 지지 보철물의 3차원적인 변화를 평가하였다. 내부연결형 임플란트를 식립하였으며 통상적인 방법으로 Screw-Cement Retained Prosthesis(SCRP) 형태의 보철물을 제작해 장착하였다. 구강스캐너(Cerec Omnicam, Dentsply Sirona, USA)를 이용해 보철물 장착 시, 장착 1주, 1개월, 1년 후 구강 스캔을 시행하였으며 디지털 분석 프로그램(Geomagic Control X, 3D systems, USA)을 이용해 기간에 따른 위치 변화를 3차원적으로 평가하였다. 인접 치아를 기준으로 보철물 장착 후 임상적인 위치 변화가 나타났으며 변화량은 시간이 지남에 따라 증가하였다.

• 전자공학회논문지 IE
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• 제43권4호
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• pp.28-36
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• 2006

본 연구에서는, 팔의 4가지 운동을 구별할 수 있는 계측 시스템과, 구별된 팔의 운동 위치를 추정할 수 있는 제어 알고리즘에 관하여 기술한다. 먼저 4가지(굽히기와 펴기, 내전과 외전) 운동을 구별하기 위해 굽혀진 정도를 측정할 수 있는 전기 저항 형태의 굽힘 센서를 사용한다. 이 센서를 왼팔의 상완 이두근과 오구완근에 1개씩 부착한다. 부착된 두 개의 센서로부터 출력되는 신호는 증폭기와 필터 등으로 구성된 계측 시스템을 통과한다. 이 시스템에서는 상완이두근에 부착된 센서 신호는 굽히기와 펴기 운동 중에서만 On/OFF 작동을 하도록 하고, 오구완근에 부착된 센서 신호는 모든 운동에 작동하도록 설계하였다. 이렇게 출력된 신호들로부터 4가지 운동은 구별하여 출력하고, 출력된 신호들로부터 팔의 운동 위치를 측정한다. 마지막으로, 제안된 알고리즘의 효용성을 입증하기 위해 RC 서보 모터와 포텐션미터로 구성된 2자유도의 인공팔을 제작하여 실험한다. 실험을 통해 인공 팔의 위치는 모터의 회전 관성, 센서의 노이즈 등으로 실제 팔의 위치와 차이가 발생하였다 이 오차를 감소하기 위해 오차값과 오차의 변화값에 근거한 퍼지 PID 제어기를 사용하였고, 이로써 오차가 5도 이내로 감소되었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.250-252
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• 2007

In this paper presents a control algorism for myoelectric hand prosthesis(MHP) with 2 degree of freedom(DOF), which consists of a mechanical hand, a surface myoelectric sensor(SMES) for measuring myoelectric signal, a control system and a charging battery. The actuation for the 2-DOF hand functions such as grasping and wrist rotation was performed by two DC-motors, and controlled by myoelectric signal measured from the residual forearm muscle. The two controllers were made of a RISC-type microprocessor, and its software was executed on a real-time kernel. The experimental results were showed that the proposed a control algorism is feasible for the MHP.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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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.

• The Journal of Advanced Prosthodontics
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• 제11권6호
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• pp.341-349
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• 2019

PURPOSE. A novel retentive type of implant prosthesis that does not require the use of cement or screw holes has been introduced; however, there are few reports examining the biomechanical aspects of this novel implant. This study aimed to evaluate the biomechanical features of cementless fixation (CLF) implant prostheses. MATERIALS AND METHODS. The test groups of three variations of CLF implant prostheses and a control group of conventional cement-retained (CR) prosthesis were designed three-dimensionally for finite element analysis. The test groups were divided according to the abutment shape and the relining strategy on the inner surface of the implant crown as follows; resin-air hole-full (RAF), resin-air hole (RA), and resin-no air hole (RNA). The von Mises stress and principal stress were used to evaluate the stress values and distributions of the implant components. Contact open values were calculated to analyze the gap formation of the contact surfaces at the abutment-resin and abutment-implant interfaces. The micro-strain values were evaluated for the surrounding bone. RESULTS. Values reflecting the maximum stress on the abutment were as follows (in MPa): RAF, 25.6; RA, 23.4; RNA, 20.0; and CR, 15.8. The value of gap formation was measured from 0.88 to 1.19 ㎛ at the abutment-resin interface and 24.4 to 24.7 ㎛ at the abutment-implant interface. The strain distribution was similar in all cases. CONCLUSION. CLF had no disadvantages in terms of the biomechanical features compared with conventional CR implant prosthesis and could be successfully applied for implant prosthesis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.265-266
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• 2010

This paper propose the test method for performance of myoelectric hand prosthesis(MHP) according to myoelectric signal generated in the human muscle. The MHP consists of a mechanical hand, a surface myoelectric sensor(SMES) for measuring myoelectric signal, a control system and a charging battery. The propose test method is proved the reliability of MHP.