Effects of Ankle Rehabilitation Exercise on Temporo-Spatial Parameters and Pressure Distribution in Radiculopathy Patient after Discectomy

Conventional ankle rehabilitation exercises can be monotonous and repetitive. The use of robots and games can complement the existing practices, provide an engaging environment for the patient and alleviate the physiotherapist’s workload. This paper presents an ankle rehabilitation robot that uses two nitinol wire actuators and a Pong game to provide foot plantarflexion and dorsiflexion exercises. Nitinol is a type of smart material that has high volumetric mechanical energy density and can produce translational motion. A two-state discrete antagonistic control is proposed to manipulate the actuators. The system was tested on healthy participants and stroke patients. The results showed that the robot was safe and compliant. The robot did not forcefully plantarflex or dorsiflex the foot when the participant exerted opposing force. The actuators worked antagonistically to flex to the foot as intended, in sync with the up and down motions of the player’s bat in the game. These behaviors demonstrated the feasibility of a nitinol-based ankle rehabilitation robot and a simple and yet intuitive game in providing interactive rehabilitation exercise. The robot is expected to enhance the patient’s experience, participation and compliance to the rehabilitation routine and to quantitatively monitor the patient’s recovery progress.

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Design and kinematic analysis of redundantly actuated parallel mechanisms for ankle rehabilitation

Robotica ◽

10.1017/s0263574714000241 ◽

2014 ◽

Vol 33 (2) ◽

pp. 366-384 ◽

Cited By ~ 16

Author(s):

Congzhe Wang ◽

Yuefa Fang ◽

Sheng Guo ◽

Changchun Zhou

Keyword(s):

Degrees Of Freedom ◽

Control Strategies ◽

Structural Characteristics ◽

Parallel Mechanisms ◽

Spherical Mechanisms ◽

Ankle Rehabilitation ◽

Redundantly Actuated ◽

Reconfigurable Capacity ◽

Three Degrees Of Freedom ◽

Rehabilitation Exercise

SUMMARYIn this paper, we present the design of two serial spherical mechanisms to substitute for a single spherical joint that is usually used to connect the platform with the base in three degrees of freedom parallel mechanisms. According to the principle derived from the conceptual design, through using the two serial spherical mechanisms as the constraint limb, several redundantly actuated parallel mechanisms are proposed for ankle rehabilitation. The proposed parallel mechanisms all can perform the rotational movements of the ankle in three directions while at the same time the mechanism center of rotations can match the ankle axes of rotations compared with other multi-degree-of-freedom devices, due to the structural characteristics of the special constraint limb and platform. Two special parallel mechanisms are selected to analyze their kinematical performances, such as workspace, dexterity, singularity, and stiffness, based on the computed Jacobian. The results show that the proposed scheme of actuator redundancy can guarantee that the redundantly actuated parallel mechanisms have no singularity, better dexterity, and stiffness within the prescribed workspace in comparison with the corresponding non-redundant parallel mechanisms. In addition, the proposed mechanisms possess certain reconfigurable capacity based on control strategies or rehabilitation modes to obtain sound performance for completing ankle rehabilitation exercise.

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Design and Kinematical Performance Analysis of a 3-RUS/RRR Redundantly Actuated Parallel Mechanism for Ankle Rehabilitation

Journal of Mechanisms and Robotics ◽

10.1115/1.4024736 ◽

2013 ◽

Vol 5 (4) ◽

Cited By ~ 42

Author(s):

Congzhe Wang ◽

Yuefa Fang ◽

Sheng Guo ◽

Yaqiong Chen

Keyword(s):

Performance Analysis ◽

Conceptual Design ◽

Parallel Mechanism ◽

Structural Characteristics ◽

Robotic System ◽

Degree Of Freedom ◽

Redundant Robot ◽

Ankle Rehabilitation ◽

Redundantly Actuated ◽

Rehabilitation Exercise

In this paper, we present the design of a novel 3-RUS/RRR redundantly actuated parallel mechanism for ankle rehabilitation based on the principle from the conceptual design. The proposed mechanism can actualize the rotational movements of the ankle in three directions while at the same time the mechanism center of rotations can match the ankle axes of rotations compared with other multi-degree-of-freedom devices, owing to the structural characteristics of the special constraint limb and platform. A new actuator redundancy scheme is used, which not only still maintains all inherent advantages from actuator redundancy but also possesses the kinematic partially decouple feature that improves the flexibility of the robotic system. Kinematic performances, such as dexterity, singularity and stiffness, are analyzed based on the computed Jacobian. Then simulation is performed. All the results show that the redundant robot has no singularity, better dexterity and stiffness within the prescribed workspace in comparison with the corresponding 3-RUS/RRR nonredundant robot, and is suitable for rehabilitation exercise.

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