While walking with a trans-femoral prosthesis, the prosthetic user needs to acquire a stable gait without abnormal gait, regardless of stride, speed, or slope angle. Conventional knee prostheses control the knee angle to reproduce the gait of healthy person. However, because they do not control based on the gait characteristics of the individual prosthetic user, the prostheses cannot follow the real-time changes in gait pattern, leading to gait disturbance. Therefore, in this study, we developed a knee angle control system that automatically adapts the flexion angle of the knee joint to the changes in gait pattern by varying the control parameters of the robotic prosthesis. Specifically, we focused on the gait characteristics before one gait cycle and proposed an adaptive gait model that follows the knee joint flexion angle to the real-time gait characteristics. Finally, we conducted clinical experiments by a trans-femoral prosthesis user and showed the effectiveness of proposed method by stabilizing the gait.

In this paper, we study cooperative distributed control for networks composed of nonlinear subnetworks. Invoking dissipation theory in the incremental stability framework, we achieve network stabilization by cooperative distributed control, ensuring incremental exponential dissipativity of each nonlinear subnetwork. Each cooperative distributed controller can be designed by solving families of linear matrix inequalities. The proposed design method is applicable to driver node selection of each subnetwork.

Measuring the range of motion (ROM) of the human body is essential for the quantitative evaluation of rehabilitation for patients with cerebrovascular disease. However, manual measurement of ROM requires enough knowledge and experience and is laborious work. Therefore, the computer-assisted system helps reduce such situations. Kinect sensor can automatically detect many joint positions in the human body and is considered adequate for applying the above system. The purpose of this study was to develop an automatic ROM measurement system by using a Kinect sensor. The system is aimed at detecting the motion for putting on and taking off clothes. For accurate ROM measurement in the motion, some joint positions, which a Kinect sensor did not give those, were estimated from the data of multiple postures. Then, ROMs on the thoracic and lumbar spine were calculated under flexion, extension, lateral bending, and rotation, and on the shoulder girdle under flexion and extension. The developed system was applied to ROM measurements for four healthy adults, and its result was compared with the results of an expert occupational therapist. Most of the measurement error between the system and an expert maintained less than 5 degrees. This system helps reduce the therapist burden in the assessing thoracic and lumber spine and shoulder girdle mobility and provides feedback to the patients on the effectiveness of rehabilitation. Further development of the system is expected to improve the current rehabilitation situation.

Watching video game is gradually becoming as popular as playing video game with development of online video streaming. Previous studies reported that playing game decreases blinking counts and mental activity increases cerebral blood flow. It is necessary to investigate whether watching video game of others influences blinking counts and cerebral blood flow. Thus, the present study was to investigate effects of watching game on blinking counts and cerebral blood flow. We also compared these responses between playing and watching game. Ten healthy males (age: 21±2years, height: 175.2±5.2cm, body mass: 68.9±5.3kg, body mass index: 22.4±1.5kg/m²) were recruited for this study. After a 5-min resting period in the sitting position, all participants completed three trials for 5-min; playing game (P), watching game (W) and control (C) trials. Blinking counts, beat-to-beat middle cerebral artery mean flow velocity (MCA V_mean) and heart rate (HR) was measured using electrooculogram, transcranial Doppler flowmetry and electrocardiogram. Blinking counts during P and W trials significantly decreased from the resting baseline (P < 0.05). The blinking count was significantly lower in P and W trials than C trial (P < 0.05). MCA V_mean during P trial significantly increased from the baseline (P < 0.05). The elevation of MCA V_mean was significantly greater in P trial than other trials (P < 0.05). No significant difference in HR was observed from baseline in all trials. These results suggest that watching video game decreases blinking count to the same extent as playing game, while cerebral blood flow was not altered during watching video game in spite of the increase during playing video game.