• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.745-746
• /
• 2012

• 대한의용생체공학회:의공학회지
• /
• 제29권3호
• /
• pp.222-230
• /
• 2008

This paper introduces a method of estimating the knee joint moment developed during MVC. By combining the Hill-type muscle model and analytic results on moment arm and musculotendon length change as a function of hip and knee joint angle, the knee joint moment at a specific knee joint angle during MVC is determined. Many differences between the estimated results and the experimental data are noted. It is believed that these differences originate from inaccurate information on the muscle-tendon parameters. The establishment of exact values for the subject's muscle parameters is almost impossible task. However, sensitivity analysis shows that the tendon slack length is the most critical parameter when applying the Hill-type muscle model. The effect of a change of this parameter on the muscle length force relationship is analyzed in detail.

• 대한전자공학회논문지
• /
• 제24권2호
• /
• pp.280-291
• /
• 1987

In this paper, the linear autoregressive model of EMG signal for four basic arm functions was presented and parameters for each function were estimated. The signal identification was carried out using function discrimination algorithm. It was validated that EMG signal was a widesense stationary process and the linear autoregressive model of EMG signal was constructed through approximating it to Gaussian process. It was confined that Levinson-Durbin algoridthm is a more appropriate one than the recursive least square method for parameter estimation of the linear model. Optimal function discrimination was acquired when sampling frequency was 500Hz and two electrodes were attached to bicep and tricep muscle, respectively. Parameter values were independent of variance and the number of minimum data for function discrimination was 200. Bayesian discrimination method turned out to be a better one than parallel filtering method for functional discrimination recognition.

• 대한의용생체공학회:의공학회지
• /
• 제15권4호
• /
• pp.429-438
• /
• 1994

An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate eleclromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocnemius m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher'stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical slimulator restored partially gait function in paraplegic patients.

• 대한기계학회논문집
• /
• 제15권6호
• /
• pp.1967-1974
• /
• 1991

본 연구에서는 근육수축에 의해 발생되는 각 신체부분의 각가속도의 방향이 다음 두가지 요소의 변화에 따라 어떻게 달라지는가를 중점적으로 살펴보기로 한다` (1) 신체매개변수(body-segmental parameter): 길이, 무게 등, (2) 신체 각 부분의 위치. 이러한 상관관계를 더욱 명확히 이해함으로써, 주어진 운동(given task)을 FES 에 의해 수행하고자 할 때 전기적으로 자극되어야 할 근육을 사전에 선택할 수 있을 것이다.

• 한국융합학회논문지
• /
• 제12권12호
• /
• pp.411-418
• /
• 2021

본 연구의 목적은 근감소증이 있는 유방암 환자를 대상으로 서로 다른 근 수축형태의 저항성 운동을 실시하여 상지 근기능 및 타액 내 사이토카인에 미치는 효과를 규명함으로써 유방암 생존자의 재발 방지를 위한 효과적인 운동프로그램의 기초자료를 제공하는데 있다. 근감소증이 있는 유방암 환자(등척성 운동집단 10명, 등장성 운동집단 10명)를 대상으로 8주간 60~70%RM의 강도로 60분 동안 주 3회 실시하였으며, 비교집단(n=10)은 일상생활을 유지하도록 하였다. 8주 운동 전후의 차이를 분석한 결과 어깨관절의 굴곡(p=.001), 외전(p=.001), 외회전(p=.045) 및 사이토카인인 IL-6(p=.000) IL-10(p=.001)의 경우 등장성 운동을 실시하였을 때 더 긍정적인 효과가 있었다.

• 한국정밀공학회지
• /
• 제21권8호
• /
• pp.171-179
• /
• 2004

The purpose of this study is to generate cycling motion for FES (functional electrical stimulation) using knee muscles only. We investigated the possibility by simulation. The musculoskeletal model used in this simulation was simplified as 5-rigid links and 2 muscles (knee extensor and flexor). For the improvement of the present feedforward control in FES, we included feedback path in the control system. The control system was developed based on the biological neuronal system and was represented by three sub-systems. The first is a higher neuronal system that generates the motion command for each joint. The second is the lower neuronal system that divides the motion command to each muscle. And the third is a sensory feedback system corresponding to the somatic sensory system. Control system parameters were adjusted by a genetic algorithm (GA) based on the natural selection theory. GA searched the better parameters in terms of the cost function where the energy consumption, muscle force smoothness, and the cycling speed of each parameter set (individual) are evaluated. As a result, cycling was implemented using knee muscles only. The proposed control system based on the nervous system model worked well even with disturbances.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 추계학술대회
• /
• pp.9-13
• /
• 1997

The present study was designed to develop the functional electrical stimulation system in order to restore motor function of paralytic patients. We attempt to establish adequate stimulus parameters for the recovery of work unction in lower limb paralysis patients and to develop the electrical stimulation system, which is effective to protect foot drop in these patients. In our animal and human experiment, adequate stimulus condition for surface electrode on the lower limb were 0.2-0.3ms at the duration and 50 Hz, which contain 600Hz train pulse. This parameter has efficiently prevented the foot drop from lower limb paralysis, decreased muscle fatigue and induced powerful contraction of lower limb muscle.

• 대한의용생체공학회:의공학회지
• /
• 제15권2호
• /
• pp.167-174
• /
• 1994

In this paper, a DSP and microcomputer-based EMG controlled functional electrical stimulation (FES) system, for restoring walking of paraplegics at the patients' own command, is presented. The above-lesion EMG is a time-varying nonstationary signal and its autoregressive (AR) parameters are identified by the nonstationary identification algorithm using a DSP chip. The identified AR parameters are used for the cloassification of the function and the control of the movement. The below-lesion response-EMG signal is used as a measure of muscle fatigue. This FES system is designed to measure muscle fatigue and control the stimulation intensity according to the amplitude of the response-EMG signal. While the automatic electrical intensity control is obtained by identifying the movement, the proposed FES system is suitable for the automatic control of paraplegic walking.

• 대한중풍순환신경학회지
• /
• 제14권1호
• /
• pp.8-14
• /
• 2013

■ Objectives The goal of this study is to find the correlation between the motor function and gait pattern of stroke patients. ■ Methods We measured Manual muscle test(MMT), Motricity index(MI) and Spatiotemporal gait parameters of admitted hemiplegic patients with stroke. The gait parameters were measured using a Treadmill gait system. ■ Results There is a significant correlation between motor function and spatiotemporal parameters such as step length, stride length, step time, stride time, total double support or cadence, in stroke patients. ■ Conclusion The better motor function of stroke was, the more gait improved.