3차원 가속도계를 이용한 동적 균형 회복 추정

태기식,김영호 대한인간공학회 2002 대한인간공학회 학술대회논문집 Vol.- No.-

In this paper, dynamic postural control against forward-backward perturbations of a platform was estimated using tri-axial accelerometers and a forceplate. Ten young healthy volunteers stood upright in comfortable condition on the perturbation system which was controlled by an AC servo motor. With anterior-posterior perturbations, movements of ankle, knee and hip joints were obtained by tri-axial accelerometers, and ground reaction forces with corresponding displacements of the center of pressure(CoP) by the force plate. The result showed that the ankle moved first and the trunk forward, which implies that the mechanism of the dynamic postural control in anterioroposterior perturbations, occurred in the procedure of the ankle, the knee and the hip. Knee flexion and hip extension in the period of acceleration, constant velocity and deceleration phase is very important for the balance recovery. These responses depends on the magnitude and timing of the perturbation. From the present study the accelerometry-system appears to be a promising tool for understanding kinematic accelerative in response to a transient platform perturbation.

뇌손상 후 운동신경기능 회복에 대한 대칭형 상지 운동기구의 효과: 기능적 뇌 자기공명영상 연구

태기식,최희석,송성재,김영호,Tae Ki-Sik,Choi Hue-Seok,Song Sung-Jae,Kim Young-Ho 한국의학물리학회 2005 의학물리 Vol.16 No.1

본 연구에서는 건측 손의 운동에 따라 환측 손이 대칭적으로 운동하며 두 가지 운동이 가능한 대칭형 상지 운동기구를 개발하고 개발된 대칭형 상지운동 기구를 이용한 6주간의 훈련 후 상지운동 기능 평가인 Fugl-Meyer 검사를 실시하고 기능적 자기공명영상(fMRI)을 통한 뇌 활성화의 변화를 관찰하였다. 편마비 환자를 위하여 건측 손의 운동을 환측 손으로 전달하여 손목의 굴곡과 신전, 전완의 회내와 회외 운동을 유도하는 대칭형 상지 운동기구를 제작하고 제작한 기구의 운동효과를 검증하기 위하여 대뇌병변이나 정신분열증 경험이 없는 오른손잡이인 성인 3명을 대조군으로 선정하고 편마비 발생 후 2년 이상 경과하여 손상된 상지의 자발적 회복과정이 끝났고 제시된 과제 수행이 가능한 만성 편마비 환자 남성 3명을 환자군으로 선정하였다. 제작된 대칭형 상지 운동기구를 이용한 총 6주간의 훈련 후 측정된 Fugl-Meyer 검사에서 훈련에 참가한 모든 편마비 환자들의 상지 운동기능이 현저하게 향상되었다. 또한 만성 편마비 환자를 대상으로 하여 제작된 기구를 적용하여 뇌 활성화를 관찰하기 위해 영상 촬영을 진행하는 동안 모든 피검자들에게 대조군에게는 우세 손을 환자군에게는 건측 손만 손잡이를 잡고 손목의 굴곡/신전 운동(과제 1)을 하고, 양손 모두 손잡이를 잡은 채로 건측 손만을 움직여서 환측 손이 수동적으로 대칭 운동(과제 2)을 하는 두 가지 과제를 수행하게 하였다. 과제 1에서는 운동 전에 비해 대측 SMC의 활성 강도가 증가되고 동측 SMC는 감소하였다. 과제 2에서는 환자에 따라 운동 전에 다양한 영역에서 활성화되다가 운동 후 양측 SMC 및 SMA, PMA 영역 등의 이차 운동영역의 재조직화가 관찰하여 각 과제에 대한 운동 전후의 대뇌 피질의 재조직화가 손의 운동성 회복과 관련이 있음을 확인하였다. 본 연구를 통해 만성편마비 환자에게 본 기구를 적용시켰을 때 물리 치료적 중재로 인한 운동기능 회복 향상과 손 운동에 대한 기능적 자기공명 영상을 비교함으로써 대뇌 피질의 재조직화를 관찰할 수 있었다. The effect of the developed symmetric upper extremity motion trainer on the cortical activation pattern was investigated in three chronic hemiparetic patients using both fMRI and Fugl-Meyer test. The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer tests were performed every two weeks during the training. fMRI was performed at 3T scanner with wrist flexion-extension in two different tasks before and after the training program: the only unaffected hand movement (Task 1) and passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral SMC but increased in contralateral SMC. Task 2 showed cortical reorganizations in bilateral SMC, PMA and SMA. Therefore, it seems that the cortical reorganization in chronic hemiparetic patients can be induced by the training with the developed symmetric upper extremity motion trainer.

직립자세에서의 전방향 동요 시 균형회복 기전

태기식,김영호 대한의용생체공학회 2003 의공학회지 Vol.24 No.5

In this paper, biomechanical aspects of dynamic대학교postural responses against forward perturbations were experimentally determined simultaneous measurements of joint angles, accelerations. EMG activations, center of pressure(CoP) movements and ground reaction forces(GRF), Thirteen young healthy volunteers, stood on a flat platform, were translated into the forward direction by an AC servo-motor at two separate velocities(0.1m and 0.2m/s). In order to recover postural balance against the forward perturbation, joint motions were observed in the sequence of the ankle dorsiflexion, the knee flexion and then the hip flexion during the later acceleration phase. Both acceleration patterns at the heel and the sacrum were shown the forward acceleration pattern during the later acceleration phase and early of constant velocity phase as increasing platform velocity, respectively. Tibialis anterior(TA) for the ankle dorsiflexion and biceps femoris(BF) for the knee flexion. the primary muscle to recover the forward perturbation, was activated during the half of acceleration phase. Ankle strategy was used for slow-velocity perturbation, but mixed strategy of both ankle and hip used for the fast-velocity perturbation. In addition, parameters of perturbation such as timing and magnitude influenced the postural response against the perturbation.

위성항법 시스템을 이용한 생체역학적 응용

태기식 한국스포츠리서치 2006 한국 스포츠 리서치 Vol.17 No.6

실버세대를 위한 텔레케어용 전자의료기기 기술개발 동향

태기식,조용석,Tae, Gi-Sik,Jo, Yong-Seok 한국전기전자재료학회 2010 전기전자재료 Vol.23 No.10

넘어짐 방지를 위한 생체역학적 반응

태기식,신화경 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.3

Dynamic postural control varies with the environmental context, specific task and intentions of the subject. In this paper, dynamic postural responses against forward and backward perturbations were experimentally determined using motion analysis system, electromyography and accelerometers. Ten young healthy volunteers, stood on a flat platform, were translated in forward and backward directions by an AC servo-motor. Joint angles, ground reaction forces(GRFs), electromyography and acceleration patterns at the heel and the sacrum were measured. The results based on the given perturbation showed that the dynamic postural balance recovery against forward-backward perturbations is achieved in the process of the ankle, the knee and then the hip. Joint flexion is important in the balance recovery against the forward perturbation, but joint extension is important against the backward perturbation. These responses depends on the magnitude and timing of the perturbation. From the present study the accelerometry-system appears to be a promising tool for understanding kinematic accelerative in response to a transient platform perturbation.

반복적 양측 운동학습에 따른 대뇌 및 소뇌 피질 활성화

태기식,송성재,김영호,Tae, Ki-Sik,Song, Sung-Jae,Kim, Young-Ho 대한의용생체공학회 2007 의공학회지 Vol.28 No.1

The aim of this study was to evaluate effects of short-tenn repetitive-bilateral excercise on the activation of motor network using functional magnetic resonance imaging (fMRI). The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer Assessments (FMA) were performed every two weeks during the training. We compared cerebral and cerebellar cortical activations in two different tasks before and after the training program: (1) the only unaffected hand movement (Task 1); and (2) passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI was performed at 3T with wrist flexion-extension movement at 1 Hz during the motor tasks. All patients showed significant improvements of FMA scores in their paretic limbs after training. fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral sensorimotor cortex but increased in contralateral sensorimotor cortex and ipsilateral cerebellum. Task 2 showed cortical reorganizations in bilateral sensorimotor cortex, premotor area, supplemetary motor area and cerebellum. Therefore, this study demonstrated that plastic changes of motor network occurred as a neural basis of the improvement subsequent to repetitive-bilateral excercise using the symmetrical upper-limb ann motion trainer.

대칭형 상지 운동기구를 이용한 손목 운동 시 뇌 활성도 패턴

태기식(K. S. Tae),김사엽(S. Y. Kim),송성재(S. J. Song),이소영(S. Y. Lee),박기영(G. Y. Park),손철호(C. H. Sohn),김영호(Y. H. Kim) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

We developed a symmetrical upper limb motion trainer for chronic hemiparetic subjects. This trainer enabled the practice of a forearm pronation/supination and wrist flexion/extension. In this study, we have used functional magnetic resonance imaging(fMRI) with the developed symmetrical upper limb motion device, to compare brain activation patterns elicited by flexion/extension wrist movements of control and hemiparetic subject group. In control group, contralateral somatosensory cortex(SMC) and bilateral cerebellum were activated by dominant hand movement(Task 1), while bilateral movements by dominant hand(Task 2) activated the SMC in both cerebral hemispheres and ipsilateral cerebellum. However, in hemiparetic subject group, contralateral supplymentary motor area(SMA) was activated by unaffected hand movement(Task 1), while the activation of bilateral movements by unaffected hand(Task 2) showed only SMA in the undamaged hemisphere. This study, demonstrating the ability to accurately measure activation in both sensory and motor cortex, is currently being extended to patients in clinical applications such as the recovery of motor function after stroke.

만성 편마비 환자의 손목 운동 시 근수축 특성

태기식(K. S. Tae),김사엽(S. Y. Kim),송성재(S. J. Song),이지용(J. Y. Lee),이영희(Y. H. Lee),김영호(Y. H. Kim) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

The purpose of this study was to investigate the characteristics between EMG timing of muscle contraction and motor impairment in chronic hemiplegic stroke patients. Delay time and co-contraction of 4 patients who had stroke less than 3 years were measured during isometric wrist flexion and extension along the 3 seconds beep signal. Onset and offset of muscle contraction were significantly delayed on the more affected sides than control sides. Offset was significantly delayed than the onset on the affected sides in wrist flexion. Also, recruitment of antagonist was larger than agonist on the affected sides. Co-contraction ratio on the affected side was significantly smaller than control sides in wrist flexion. In affected sides, Fugl-Meyer motor assessment(FMA) shows the correlation of onset delay in wrist flexion and extension. However, co-contraction ratio correlated with FMA in wrist flexion. EMG assessment is likely to be useful outcome measure and provide insights into mechanism for motor recovery in stroke patients.

전후방향의 플랫폼 이동에 대한 동적균형 회복 특성

태기식(K. S. Tae),김영호(Y. H. Kim) 한국정밀공학회 2002 한국정밀공학회 학술발표대회 논문집 Vol.2002 No.10월