An Evaluation of Lower Limb Motor Ability Based on Xception-LSTM / 中国康复理论与实践

Objective:To establish an algorithm to quantitatively evaluate the lower limb motor ability. Methods:From August, 2016 to March, 2017, 40 subjects were divided into young healthy group (n = 20), middle-aged group (n = 10) and elderly group (n = 10). The gait video, knee angle and ground reaction force of the subjects were collected, and the gait contour was extracted from the gait video by using the ViBe algorithm. The gait image feature was extracted by Xception-LSTM, and fused it with the knee joint angle and the ground reaction force in the feature layer. The fusion features were reduced in dimension by kernel principal component analysis, and the gait ability score (GAS) was established. All the subjects were assessed with Wisconsin Gait Scale (WGS). Results:GAS was less in middle-aged group and elderly group than in the young healthy group (t > 4.164, P < 0.01), and was less in the elderly group than in the middle-aged group (t = 7.338, P < 0.01). GAS was negative correlated with the score of WGS (r = -0.91, P < 0.01). Conclusion:The lower limb exercise ability could be quantified with GAS, which may be applied in developing rehabilitation and fitting walking aids.

Development of Dynamic Ankle Prosthesis (review) / 中国康复理论与实践

Mechanism design and control theory of dynamic ankle prosthesis are important research directions of active lower limb prosthesis. This paper started from the research status at home and abroad, reviewed the background, purpose and significance of dynamic ankle prosthesis, pointed out the shortcomings of passive ankle prosthesis design and kinematics, provided opinions and suggestions for the design and development of powered ankle prosthesis. According to the different driving modes, the research progress of pneumatic, hydraulic and motor driven ankle prosthesis mechanism design was systematically described, and the timeliness and energy dissipation of prosthesis under different driving modes were discussed. According to the different feedback accuracy and real-time of finite-state machine, trajectory tracking and direct volitional control, an optimization scheme was proposed to improve the function of dynamic ankle prosthesis control mode.