• 한국정밀공학회지
• /
• 제29권7호
• /
• pp.723-729
• /
• 2012

Spring-like leg models have been employed to explain various dynamic characteristics in human walking. However, this leg stiffness model has limitations to represent complex motion of actual human gait, especially the behaviors of each lower limb joint. The purpose of this research was to determine changes of total leg stiffness and lower limb joint stiffness with gait speed in knee osteoarthritis. Joint stiffness defined as the ratio of the joint torque change to the angular displacement change. Eight subjects with knee osteoarthritis participated to this study. The subject walked on a 12 m long and 1 m wide walkway with three sets of four different randomly ordered gait speeds, ranging from their self-selected speed to maximum speed. Kinetic and kinematic data were measured using three force plates and an optical marker system, respectively. Joint torques of lower limb joints calculated by a multi-segment inverse dynamics model. Total leg and each lower limb joint had constant stiffness during single support phase. The leg and hip joint stiffness increased with gait speed. The correlation between knee joint angles and torques had significant changed by the degree of severity of knee osteoarthritis.

• 대한산업공학회지
• /
• 제23권4호
• /
• pp.779-791
• /
• 1997

The purpose of this study is to measure a perceived joint discomfort in the seated and standing position, and to provide ranking systems of perceived joint discomfort. Nineteen mole subjects with no history of musculo-skeletal disorders participated in the experiment. Their physical characteristics were: age $-25.4{\pm}2.7$years, stature $-171.9{\pm}6.0cm$, and body weight $-67.1{\pm}7.0kg$. The results showed that the perceived joint discomforts were different depending upon the joints involved in motion and their movement directions (degree of freedom of motions), which implied that the human body motions and their degrees of freedom should be classified into several distinct classes that need to be assigned different weights of postural stress. Therefore, three ranking systems based on the perceived joint discomforts were suggested, which were classified by the degree of freedom of motions and joints, by only degree of freedom motions, and by joints involved in motion, respectively. In the seated position, the hip movement was the most stressful, the bock was the second, and the shoulder was the third. Likewise, in the standing postures, the hip was the most, the bock was the second, and the ankle was the third. It was expected that these joint motion ranking systems could be used by practitioners of health and safety to improve the comfort of working postures in industry.

• 한국군사과학기술학회지
• /
• 제22권6호
• /
• pp.806-814
• /
• 2019

One of the future weapon systems is the individual smart weapon which has a structure mounted on the forearm of soldiers. The structure may cause injuries or affect the accuracy of fire due to its impact on joints when shooting. This paper proposes human-impact interaction modeling and a verification methodology in order to estimate the impact of fire applied to the forearm. For this purpose, a human musculoskeletal model was constructed and the joints' behavior in various shooting positions was simulated. In order to verify the simulation results, an impact testing device substituting the smart weapon was made and the experiment was performed on a real human body. This paper compares the simulation results performed under various impact conditions and the experimental values in terms of accuracy and introduces methods to complement them. The results of the study are expected to be a basis for a reliable human-impact interaction modeling, and smart individual weapon development.

• 한국정밀공학회지
• /
• 제21권12호
• /
• pp.182-191
• /
• 2004

This study is focused on the development of a child human model, which is composed of skin, skeleton, joints and muscle, etc. The dimension of child outer skin is referred to anthropometric data from KRISS (Korea Research Institute of Standards and Science). The positions of joint and mass properties of body segments are calculated from ATB(Articulated Total Body) program, GEBOD. The properties of bones and muscles are obtained by the way of scaling from adult human model. To verify the developed human model, ROM simulation and sled test is conducted. Developed human model can be effectively applied to the evaluation of human injury in crash situation and development of child restraint system. The explicit finite element program $PAM-CRASH^TM$ was used to simulate six-year old child human model.

• Biomolecules & Therapeutics
• /
• 제28권5호
• /
• pp.414-422
• /
• 2020

Fangchinoline (FAN) is a bisbenzylisoquinoline alkaloid that is widely known for its anti-tumor properties. The goal of this study is to examine the effects of FAN on arthritis and the possible pathways it acts on. Human fibroblast-like synovial cells (FLS), carrageenan/kaolin arthritis rat model (C/K), and collagen-induced arthritis (CIA) mice model were used to establish the efficiency of FAN in arthritis. Human FLS cells were treated with FAN (1, 2.5, 5, 10 µM) 1 h before IL-1β (10 ng/mL) stimulation. Cell viability, reactive oxygen species measurement, and western blot analysis of inflammatory mediators and the MAPK and NF-κB pathways were performed. In the animal models, after induction of arthritis, the rodents were given 10 and 30 mg/kg of FAN orally 1 h before conducting behavioral experiments such as weight distribution ratio, knee thickness measurement, squeaking score, body weight measurement, paw volume measurement, and arthritis index measurement. Rodent knee joints were also analyzed histologically through H&E staining and safranin staining. FAN decreased the production of inflammatory cytokines and ROS in human FLS cells as well as the phosphorylation of the MAPK pathway and NF-κB pathway in human FLS cells. The behavioral parameters in the C/K rat model and CIA mouse model and inflammatory signs in the histological analysis were found to be ameliorated in FAN-treated groups. Cartilage degradation in CIA mice knee joints were shown to have been suppressed by FAN. These findings suggest that fangchinoline has the potential to be a therapeutic source for the treatment of rheumatoid arthritis.

• 한국멀티미디어학회논문지
• /
• 제20권8호
• /
• pp.1248-1257
• /
• 2017

We propose a frequency estimation algorithm of human movements using Kinect. We collect the 3D coordinates of the joints of a human body and then obtain the frequency-domain description of the movements using the discrete Fourier transform (DFT). By choosing the frequency with the biggest magnitude in the selected frequencies of each of human's joint, we obtain the major beat of the human movements. Experimental results show that the proposed algorithm accurately estimates the frequency of human movements. We expect that the proposed algorithm would be applied to many AR and VR applications as a preprocessing.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.1180-1185
• /
• 2004

The purpose of this study is to develop a Multi-joint rehabilitation system (CMRS : C&R Lab. Multi-joint Rehabilitation System). This study presents the mechanism of rehabilitation system that enables rehabilitation of multi-joint with kinematical analysis for joints of human body. Also, the relative positioning between human subjects and the head part to rehabilitate for the mechanism is based on robotics and anatomy. This study was verified with simulations. Finally, Automation of positioning was realized. Rehabilitation exercises in passive mode were enabled with the results.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.84.2-84
• /
• 2002

$\textbullet$ The dynamic model of a floating human body is derived $\textbullet$ Introduction to impact model for human body $\textbullet$ Analysis of external impulse on the sole $\textbullet$ Analysis of internal impulse at the joints $\textbullet$ It is shown through simulation that the internal impulses for two different configurations

• Journal of Acupuncture Research
• /
• 제23권2호
• /
• pp.125-137
• /
• 2006

Objectives : The effect of water extract of the pilose antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe (Nokyong), a traditional immuno-suppressive and immuno-activating Korean oriental medicine, on collagen-induced arthritis (CIA) mice model was studied. Identification of common Nokyong capable of affording protection or modulating the onset and severity of arthritis may have important human health implications. Methods : Nokyong has shown to possess anti-inflammatory and anticarcinogenic properties in experimental animals. In this study we determined the effect of DAE on collagen-induced arthritis in mice. Results : In three independent experiments mice given DAE in water exhibited significantly reduced incidence of arthritis (33% to 50%) as compared with mice given no DAE in water (84% to 100%). The arthritis index also was significantly lower in DAE-fed animals. Western blot analysis showed a marked reduction in the expression of inflammatory mediators such as cyclooxygenase 2 (Cox-2), $Interferon-{\gamma}\;(INF-{\gamma})$, and tumor necrosis factor ${\alpha}\;(TNF-{\alpha})$ in arthritic joints of DAE-fed mice. The neutral endopeptidase (NEP) activity was approximately 6-fold higher in arthritic joints of non-DAE-fed mice in comparison to nonarthritic joints of nonimmunized mice whereas it was only 2-fold higher in the arthritic joints of DAE-fed mice. Additionally, total IgG and type II collagen-specific IgG levels were lower in the arthritic joints of DAE-fed mice. Conclusion : Taken together our studies suggest that DAE may be useful in the prevention of onset and severity of arthritis.

• 대한의용생체공학회:의공학회지
• /
• 제24권6호
• /
• pp.495-500
• /
• 2003

본 연구의 목적은 컴퓨터 그래픽 모델을 사용하여 보행 시 족부 관절의 기구학적 특성을 알아보는 것이었다. 모델에서 모든 관전은 단일중심(monocentric), 1 자유도 힌지 관절로 구성되었다. 보행 시 족부의 모션데이터는 4대의 카메라를 사용한 모션측정기로 얻었으며, 이 모션데이터를 피험자의 밭의 크기에 맞게 스케일링된 모델에 입력하여 시뮬레이션을 수행하였다. 첫 번째 발목발허리관절(tarsometatarsal joint)의 운동 범위(range of motion)는 $-8^{\circ}\;\~\;-13^{\circ}$ 이었으며, 발허리발가락관절(metatarsophanlangeal joint)에서의 운동범위는 $-13^{\circ}\;\~\;-48^{\circ}$ 이었다. 발목발허리관절과 발허리발가락관절에서의 기구학적인 데이터는 이전 연구와 비교했을 때 비슷한 경향을 나타내었다. 따라서 본 연구에서 제시하는 컴퓨터 그래픽을 기반으로 한 족부 모델링은 족부 관절의 생체역학적 해석을 위한 유용한 방법이라 할 수 있을 것이다.