Abstract
Clinical studies have demonstrated that robot-involved therapy can effectively improve the rehabilitation training effect of motor ability and daily behavior ability of subjects with an upper limb motor dysfunction. This paper presents an impedance-based assist-as-needed controller that can be used in robot-aided rehabilitation training for subjects with an upper extremity dysfunction. Then, the controller is implemented on an end-effector upper extremity rehabilitation robot which could assist subjects in performing training with a spatial trajectory. The proposed controller enables subjects’ arms to have motion freedom by building a fault-tolerant region around the rehabilitation trajectory. Subjects could move their upper limb without any assistance within the fault-tolerant region while the robot would provide assistance according to the subjects’ functional ability when deviating from the fault-tolerant region. Besides, we also put forward the stiffness field around the fault-tolerant region to increase the robot’s assistance when subjects’ hand is moving outside the fault-tolerant region. A series of columnar rigid walls would be constructed in the controller according to the subjects’ functional ability, and the stiffness of the wall increases as the motion performance deteriorates. Furthermore, the controller contains five adjustable parameters. The controller would show different performances by adjusting these parameters and satisfy the requirement of robot-aided rehabilitation training at different rehabilitation stages such as passive, assistant, active, and resistant training. Finally, the controller was tested with an elderly female participant with different controller parameters, and experimental results verified the correctness of the controller and its potential ability to satisfy the training requirements at different rehabilitation stages. In the close future, the proposed controller in this work is planned to be applied on more subjects and also patients who have upper limb motor dysfunctions to demonstrate performance of the controller with different parameters.
Highlights
In recent years, the number of subjects with upper extremity motor dysfunctions caused by stroke, spinal cord injuries, and accidents has been dramatically increasing year by year [1], severely limiting their motor and activities of daily living (ADL) abilities.This brings physical inconvenience to the subjects and brings financial and mental burden to their families
Research results have showed that compared with the traditional manual rehabilitation therapy, robot-aided rehabilitation training could carry out high-intensity repetitive and task-oriented training tasks [2], and clinical research studies have shown that robot-aided rehabilitation therapy could effectively improve the rehabilitation effect on patients’ upper extremity motor abilities [3,4]
This section mainly provides experiments under four different conditions to illustrate the correctness of the controller proposed in this paper for passive, assistant, active, and resistant robot-aided rehabilitation training for patients with an upper extremity motor dysfunction
Summary
The number of subjects with upper extremity motor dysfunctions caused by stroke, spinal cord injuries, and accidents has been dramatically increasing year by year [1], severely limiting their motor and activities of daily living (ADL) abilities. This brings physical inconvenience to the subjects and brings financial and mental burden to their families. Clinical comparative trial results have showed that compared with the exoskeleton upper limb rehabilitation robot, intervention with the end-effector rehabilitation robot was more effective in terms of the active participation of patients with mild and severe stroke [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
