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

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.13 no.1
• /
• pp.10-18
• /
• 2003

This paper presented a design and control of a biped walking RGO(robotic gait orthosis) and its simulation. The biped walking RGO was distinguished from the other one by which had a very light-weight and a new RGO system will be made of 12-servo motors and 12-controllers. The vibration evaluation of the dynamic PLS(posterior leaf splint) on the biped walking RGO was used to access by the 3-axis accelerometer with a low frequency vibration of less than 30 Hz. The galt of the biped walking RGO depends on the constrains of mechanical kinematics and the initial posture. The stability of dynamic walking was investigated by analyzing the ZMP (zero moment point) of the biped walking RGO. It was designed according to the human wear type and was able to accomodate itself to the environments of S.C.I. Patients. The Joints of each leg were adopted with a good kinematic characteristics. To analyse joint kinematic properties. we made the strain stress analysis of the dynamic PLS and the analysis study of FEM with a dynamic PLS.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.11 no.4
• /
• pp.349-354
• /
• 2017

In this study, we proposed a design guideline of height-adjustable wash basin which is an assistive product for personal hygiene for persons with disability. We performed biomechanical assessments using both of conventional and prototype height adjustable wash basin. Total five elderly subjects (all male, age $68.6{\pm}4.3yrs.$, height $169.8{\pm}5.7cm$, weight $70{\pm}7.7kg$) participated for the assessment test. Each joint angles were measured by using a 3D motion capture system when subjects use wash basins, and the lumbar moment of each subjects was estimated based on a human body model. From the assessment results, a design guideline which has the range of the height from 652[mm] to 1162[mm] was proposed. Then additional assessment tests with five healthy subjects ($25.8{\pm}1.8yrs.$, $175.5{\pm}5.8cm$, $74{\pm}15.7kg$) were performed in order to verify effectiveness of the design guideline. The results showed a height-adjustable wash basin applied the proposed design guideline was effective to reduce the lumbar moment.

• Journal of Biomedical Engineering Research
• /
• v.23 no.2
• /
• pp.131-137
• /
• 2002

The remote monitoring system including hemodynamic information and pump status of the implanted animal could be helpful during the in vivo experiment or clinical trial for an artificial heart Implantation. In order to monitor the course of the in vivo experiment continuously and anywhere, web-based remote monitoring system was developed, which can monitor pressures(AoP, LAP, RAP, PAP) and flow information as well as the pump operating conditions. The system consists of data sending, storing viewer part. The data sending part was constructed using component object model and the viewer part was constructed using the Java applet. In addition, the dialog box was introduced to communicate earth other instantly and the alarming function was also introduced when the hemodynamic values were out of the desired ranges. The developed remote monitoring system was applied during the in vivo experiment of the BVAD (Bi-ventricular Assist Device) implantation for 1 month and showed designed work without failure.

• Progress in Medical Physics
• /
• v.6 no.2
• /
• pp.111-125
• /
• 1995

The stress distribution of bone is altered by the rigid bone plate, sometimes resulting in unfavorable osteoporosis. The rigidity and the biocompatibility are important factors for the design of prosthesis, however, it is also necessary to consider the effect on the bone remodeling. In this paper, it is attempted to establish an approximate and simple method to predict the trend of the configuration of surface bone remodeling upon a bone plate using stress analysis. Thus, three dimensional finite element model of plated-human femur is generated and simulated. In addition, the stress difference method (SDM) is introduced and attempted to demonstrate the configuration of surface bone remodeling of the plated-human femur.

• Proceedings of the ESK Conference
• /
• 1998.04a
• /
• pp.40-45
• /
• 1998

본 연구에서는 현장 작업자 개인이 느끼는 심리/환경적 부하를 정량적으로 파악할 수 있는 척도를 개발하였다. 이러한 척도는 현장의 중간관리자들이 간단한 기구와 직접 관찰을 통해 쉽게 사용할 수 있도록 설계되었다. 심리적 작업부하 측정은 기존 연구와 현장 작업자를 대상으로 한 인터뷰 결과를 바탕으로, 타당도가 높다고 인정되는 심리부하 측정 요소를 결정하였고, 문헌과 모의 검사를 통하여 부 담감이나 편의(bias)를 줄일 수 있도록 문항수 및 어휘를 선택하였으며, 각각의 설문은 다양한 문체 중 가장 신뢰도가 높은 형태를 선정하였다. 환경적 작업부하 측정은 문헌 조사를 통하여 측정을 위한 요소를 결덩하였고, KS 규격을 기존으로 새로운 환경부하 측정 지침서를 개발하였고, 현장 예비조사가 실시되었다. 또한, 환경부하 측정결과를 지수화하기 위한 수리적 모델과, 심리적척도와의 통합을 위 한 수리적 방법론이 제시되었다. 이러한 설문 문항과 환경조사방법은 작업장을 대상으로 적용하여 실 제로 그 효용성 여부를 검토하였다. 연구 결과 이제까지 소홀히 여겨왔던 작업자의 심리적/환경적 부 하를 정량적으로 간편하게 측정할 수 있는 방법이 개발되었고, 정량화한 심리/환경 부하 척도는 이제 까지 주로 조사되었던 생체역학적/생리적 부담도와 더불어 종합적인 작업부하 평가에 일익을 담당할 것으로 예상된다. 또한, 이러한 척도에 의한 결과는 현장 근로자들의 근로여건 개선을 위하여 노/사/ 정부 모두가 만족할 수 있는 객관적 자료로 사용될 수 있으며, 예방차원의 안전관리에도 응용될 수 있 을 것으로 기대한다.구로 신체의 종합적인 만족도, 선호를 취급하고 있을 뿐 신체각 부위의 만족 도나 선호에 관한 자세한 고찰을 하고 있지 않으며 자신의 신체에 대한 인식도 및 실제체형과의 비교는 이루어지고 있지 않다. 이에, 신체 각 부위에 대한 인식도 및 실제 신체 측정치와 만족도와의 관계 및 이상형에 대해 구체적으로 파악할 필요가 있다. 또한, 신체에 대한 이상형은 시대의 여러 여건에 따라서 변화할 수 있으므로 의복 착용자가 의복을 통해서 표현하고자 하는 이상형의 시대적 변화를 살펴볼 필요가 있다. 따라서 본 연구에서는 신체에 대한 인식도 및 만족도, 이상형에 대한 설문지 조사와 신체측정을 통하여 신체 크기에대한 만족도를 객관적인 척도로 고찰하고, 이상형과 실제 체형에 관하여 고찰하고자 한다. 도한, 1992년도 자료와의 비교를 통하여 시대에 따른 신체만족도와 이상형의 변화를 파악하고자 한다. 이를 기초로 한 의복원형 제작 및 의복 디자인에 대한 연구를 통해 의복의 맞음새가 좋을뿐만 아니라 의복착용자들 에게 심리적 만족을 줄 수 있는 의복 제작에 도움이 될 수 있을 것이다.적입지로 분석되었다.등 다양한 모형들을 고려해 본 뒤, 적절한 모형을 적용할 것이다. 가로망 설계 모형에서 신호제어를 고려하기 위해서는 주어진 가로망에 대한 통행 배정과정에서 고려되는 통행시간을 링크통행시간과 교차로 지체시간을 동시에 고려해야 하는데, 이러한 문제의 해결을 위해서 최근 활발히 논의되고 있는 교차로에서의 신호제어에 대응하는 통행배정 모형을 도입하여 고려하고자 한다. 이를 위해서 지금까지 연구되어온 Global

• Journal of the Korean Institute of Intelligent Systems
• /
• v.14 no.5
• /
• pp.610-616
• /
• 2004

In the research of biomechanical engineering, robotics and neurophysiology, to clarify the mechanism of human bipedal walking is of major interest. It serves as a basis of developing several applications such as rehabilitation tools and humanoid robots. Nevertheless, because of complexity of the neuronal system that interacts with the body dynamics system to make walking movements, much is left unknown about the details of locomotion mechanism. Researchers were looking for the optimal model of the neuronal system by trials and errors. In this paper, we applied Genetic Programming to induce the model of the nervous system automatically and showed its effectiveness by simulating a human bipedal walking with the obtained model.

• Korean Chemical Engineering Research
• /
• v.60 no.1
• /
• pp.86-92
• /
• 2022

Recently, the bio-healthcare market is enlarging worldwide due to various reasons such as the COVID-19 pandemic. Among them, biometric measurement and analysis technology are expected to bring about future technological innovation and socio-economic ripple effect. Existing systems require a large-capacity battery to drive signal processing, wireless transmission part, and an operating system in the process. However, due to the limitation of the battery capacity, it causes a spatio-temporal limitation on the use of the device. This limitation can act as a cause for the disconnection of data required for the user's health care monitoring, so it is one of the major obstacles of the health care device. In this study, we report the concept of a standalone healthcare monitoring module, which is based on both triboelectric effects and electromagnetic effects, by converting biomechanical energy into suitable electric energy. The proposed system can be operated independently without an external power source. In particular, the wireless foot pressure measurement monitoring system, which is rationally designed triboelectric sensor (TES), can recognize the user's walking habits through foot pressure measurement. By applying the triboelectric effects to the contact-separation behavior that occurs during walking, an effective foot pressure sensor was made, the performance of the sensor was verified through an electrical output signal according to the pressure, and its dynamic behavior is measured through a signal processing circuit using a capacitor. In addition, the biomechanical energy dissipated during walking is harvested as electrical energy by using the electromagnetic induction effect to be used as a power source for wireless transmission and signal processing. Therefore, the proposed system has a great potential to reduce the inconvenience of charging caused by limited battery capacity and to overcome the problem of data disconnection.

• Membrane Journal
• /
• v.28 no.6
• /
• pp.388-394
• /
• 2018

Carbon nanotube (CNT) based membranes are promising candidates for separation membranes by showing high water transport rate and ion rejection rate according to their radii. The ion selectivity is an important factor to discover the full potential of CNT membranes, and it is affected by the functionalization of CNTs. With multivalent/size ion mixtures, the ion selectivity is affected by not only ion-functional groups interaction but also ion-ion interactions and ion size exclusion in a complex manner. In this study, molecular dynamics simulations are performed to study the ion selectivity of functionalized carbon nanotubes when multivalent/size ions are contained. The permeation energy barriers are calculated by plotting potential of mean force profiles, and various factors, such as CNT size and partial charges, affecting ion selectivity are investigated. The results presented here will be useful for designing CNT membranes for ion separation, biomimetic ion channels, etc.

• Journal of the Korean Society of Safety
• /
• v.12 no.3
• /
• pp.178-184
• /
• 1997

Many mathematical techniques have been developed to determine the muscle forces and force distribution in biomechanical human model, because it is so important to understand internal forces resisting external loading. However, a three-dimensional mathematical model of wrist joint, which is essential to develop solid modeling and artificial wrist joint, has not been well developed. This study proposed to define three-dimensional mathematical model of distal radius and ulna of the human wrist and to develop a detailed two-dimensional finite element through comparisons to existing analytical models and experimental tests. This mathematical model were accurately recreated, allowing the internal tendon force as well as force transmission and distribution through the distal radios and ulna during dynamic loadings. The results found in this study indicate and support the findings of other investigator that cyclic loading condition results in higher compression force on distal radius and ulna and may be source of wrist disorder.