• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.5
• /
• pp.990-992
• /
• 2007

The purpose of this study is to develop a practical gait-event detection system which is necessary for the FES (functional electrical stimulation) control of locomotion in paralyzed patients. The system is comprised of a sensor board and an event recognition algorithm. We focused on the practicality improvement of the system through 1) using accelerometer to get the angle of shank and dispensing with the foot-switches having limitation in indoor or barefoot usage and 2) using a rule-base instead of threshold to determine the heel-off/heel-strike events corresponding the stimulation on/off timing. The sensor signals are transmitted through RF communication and gait-events was detected using the peaks in shank angle. The system could detect two critical gait-events in all five paralyzed patients. The standard deviation of the gait events time from the peaks were smaller when 1.5Hz cutoff frequency was used in the derivation of the shank angle from the acceleration signals.

• Journal of Korean Physical Therapy Science
• /
• v.15 no.3
• /
• pp.65-72
• /
• 2008

Background : The purpose of present study was to investigate the effect of quadriceps femoris taping in normal gait using 3D motion capture technique. Method : Twenty healthy volunteers, have no musculoskeletal problems, were recruited as subjects for this study. In experimental group, 20 healthy young(males 10 and females 10) were included. The subjects were assessed during two conditions: control tape(no muscle stretched) and quadriceps (muscle stretched)taping application. To obtain the dynamic data, we captured the motion of subject attached markers without taping during repeated gaits five times or more in 7 m Capture volume of gait analysis center. The result was obtained as a mean value in three times. After taping on quadriceps femoris, the same procedure was carried out. Statistical analysis were performed using statistical software packagess SPSS WIN 12.0(SPSS, Chicago, IL, USA). Differences were tested for statistical significance using paired t-test, independent t-test, chi-squared test for comparisons between the muscle stretched and no muscle stretched. Results : The date of 20 subjects who carried out the whole experimental course were statistically analyzed. 1. gait velocity was showed that muscle stretched group had more significantly increased than no muscle stretched group(p<.05). 2. step length was showed that muscle stretched group had more significantly increased than no muscle stretched group(p<.05). 3. cadens was showed that muscle stretched group had more significantly increased than no muscle stretched group(p<.05). Conclusion : kinesio taping on quadriceps femoris promoted cadence, gait velocity, step length in normal subject (muscle stretched) group.

• Physical Therapy Rehabilitation Science
• /
• v.11 no.3
• /
• pp.344-349
• /
• 2022

Objective: The purpose of the present study was to determine whether sit to stand training combined with ultrasound improves the spasticity, muscle strength and gait speed in stroke patients Design: Randomized controlled study Methods: The current study included 40 stroke patients, who were randomly divided into two groups: the sit to stand training with ultrasound (USTS) group (n=20) and the sit to stand training (STS) group (n=20). All the participants underwent 30 sessions of STS training (thirty minutes, five days per week for six weeks). Additionally, the USTS group received ultrasound therapy. The present study evaluated the spasticity of ankle plantar-flexors by the composite spasticity score. The muscle strength and gait speed were evaluated using the handheld dynamometer and the 10-meter walk test, respectively. Results: The USTS group and the STS group showed significant improvements in spasticity, muscle strength and gait speed after the intervention (p<0.05). Significant improvement in the spasticity, muscle strength, and gait speed were observed in the USTS group compared to the control group (p < 0.05). Conclusions: The results of the current study imply that sit to stand training combined with ultrasound is a beneficial and effective therapeutic modality that can be employed to improve the spasticity, muscle strength and gait speed in stroke patients.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.5
• /
• pp.407-412
• /
• 2015

This paper presents the design of a lab-built powered knee prosthesis based on a BLDC motor, a sensored impedance control using a force sensor, and a sensorless impedance control through torque estimation. Firstly, we describe the structure of the lab-built powered knee prosthesis and its limitations. Secondly, we decompose the gait cycle into five stages and apply the position-based impedance control for the powered knee prosthesis. Thirdly, we perform an experiment for the torque estimation and the sensorless impedance control of the prosthesis. The experimental results show that we can use the torque estimation to control the low impedance during the swing phase, although the estimated torque data has a delay compared with the measured torque by a load cell.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.9
• /
• pp.860-865
• /
• 2010

This paper deals with gait assisting rehabilitation robot which helps SCI patient walk again. We propose new concept of orthotic for robot considering motions of Hip and Knee Joints, and how to fit the robot to a user in terms of weight balance and comfortable standing. Then we describe our first engineering sample being designed based on the passive orthotic and show how to make the robot work for SCI patient in basic operation.

• The Journal of Korea Robotics Society
• /
• v.12 no.2
• /
• pp.144-151
• /
• 2017

An important characteristic of people with partially impaired walking ability, such as incomplete paraplegics, is that they are able to generate voluntary motion of lower-limbs. Therefore, wearable robots for the incomplete paraplegic patients require a different assistance method compared to those of complete paraplegics. First, the wearable robot should be controlled to not resist wearer's motion. Second, it should be able to generate assistive torque accurately when needed. In this paper, a wearable robot, called EROWA, for the incomplete paraplegic patients is introduced. EROWA utilizes compact rotary series elastic actuators (cRSEAs) and a control method called the zero impedance control to reduce the mechanical resistance. An assistive torque trajectory is proposed to assist gait in this paper. The proposed method is verified by simulation and experimental studies.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.7
• /
• pp.723-733
• /
• 1988

In this paper, A model of 4-legged walking robot is presented by investigating the gait of animals, which can walk with maintaining static stability on irregular terrain. Kinematices of the model robot was analyzed by geometric approach, and a gait control algorithm is proposed for the effective walking on irregular terrain. Terrains are classified into 4 types in order to study the terrain adaptability of the proposed algorithm and it is simulated for each type of terrain.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.8
• /
• pp.749-753
• /
• 2007

In this paper, a generalized version of the Motion Silhouette Image(MSI) called the Generic Motion Silhouette Image (GMSI) is proposed for gait recognition. The GMSI is a gray-level image and involves the spatiotemporal information of individual motion. The GMSI not only generalizes the MSI but also reflects a flexible feature of a gait sequence. Along with the GMSI, we use the Principal Component Analysis(PCA) to reduce the dimensionality of the GMSI and the Nearest Neighbor(NN) for classification. We apply the proposed feature to NLPR database and compare it with the conventional MSI. Experimental results show the effectiveness of the GMSI.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.6
• /
• pp.518-523
• /
• 2015

This paper proposes a gait phase classifier using a Recurrent Neural Network (RNN). Walking is a type of dynamic system, and as such it seems that the classifier made by using a general feed forward neural network structure is not appropriate. It is known that an RNN is suitable to model a dynamic system. Because the proposed RNN is simple, we use a back propagation algorithm to train the weights of the network. The input data of the RNN is the lower body's joint angles and angular velocities which are acquired by using the lower limb exoskeleton robot, ROBIN-H1. The classifier categorizes a gait cycle as two phases, swing and stance. In the experiment for performance verification, we compared the proposed method and general feed forward neural network based method and showed that the proposed method is superior.

• The Journal of Korean Physical Therapy
• /
• v.21 no.3
• /
• pp.33-40
• /
• 2009

Purpose: This study examined the effects of a virtual reality-based exercise program on the functional recovery of balance and gait in chronic stroke subjects. Methods: A total of 42 chronic stroke patients were enrolled in this study. The participants were allocated randomly to 2 groups: a VR (n=22) and control group (n=20). Both groups received treadmill training for 3 sessions (10 minutes each), 30 minutes per week over a 6 week period. The VR group practiced additional virtual reality programs consisting of 3 programs for 10 minutes each. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. Results: The virtual reality-based exercise group showed significant increases in gait velocity, cadence and stride length compared to the control group (p<0.05). However, there were no significant differences in static balance. Conclusion: These results support the perceived benefits of exercise programs that incorporate virtual reality to augment the balance and ambulation of stroke patients. Therefore, virtual reality is feasible and suitable for stroke patients