A wrist motion simulator or wrist motion actuator is a system that actuates a cadaver wrist to control the joint and move it through a variety of motions. Active wrist motion actuators apply forces directly to the tendons of interest to manipulate wrist position in a manner similar to in-vivo active motion.

Active wrist motion actuators have been approached in many different ways, however no clear design standard has been developed. Existing systems often require hardware and software proprietary to the investigators, preventing other researchers from easily replicating the work. This thesis presents the development and testing of an economical, accessible and open-source wrist motion actuation system. The full design, software code and files needed to replicate the device are all available from an online repository.

An open-source system of four linear actuators driven by a micro-controller was developed to apply tension to cadaver wrist tendons under program control. The control algorithm compared current wrist angular position with a target position as a function of time and generated actuator motions to move the wrist towards the target position.

The actuation system was tested with a soft embalmed cadaver wrist that was suture connected to the system using four tendon attachment points. The system of four linear actuators driven by the micro-controller applied tension to the sutures under program control. Wrist angular position data was collected in real time using an electromagnetic tracking system and delivered to the Actuation System via serial communication link. The system was tested by taking the wrist through 25 cycles of five different motions:​ flexion-extension, radioulnar deviation, dart throw, clockwise and counter-clockwise circumduction and angular position data was recorded as a function of time.

This work shows that a functional wrist motion actuator can be constructed based on an economical micro-controller system to provide adequate control of four tendons through a simple C program.