Design and Control of an Active Wrist Orthosis for Rehabilitation

In this study, an active orthosis has been designed to rehabilitate patients with weak wrist flexor and extensor muscles.

First, the mechanical design of the actuating mechanism with a linear servo motor to provide the desired wrist rotation, is performed in SolidWorks software. Also, to determine the force created by the actuator during flexion and extension of the wrist, the movement of the mechanism is simulated in Visual Nastran software. After molding the patient's wrist, the main body of the orthosis is made by forming the thermoplastic sheets on the mold, and the components of the mechanical part of the mechanism are installed on it.  Then, the hardware part of the electronic circuits to drive the motor and to communicate between the control modules and the actuator is designed. For the programming of microcontrollers and synchronizing of deriver to the joystick, Bascom AVR software is used. The simulation of electrical circuit is performed in Proteus software and the printed board circuit is made in Altium Designer software.

The results of applying this orthosis on the wrist of a healthy subject indicate its proper performance in creating an acceptable angle range for the wrist extension and flexion.

The use of the designed active wrist orthosis can improve the rehabilitation process of the patients with weakness in their wrist muscles.