Mechanical design and assessment of a low-cost 7-DOF prosthetic arm for shoulder disarticulation

This work presents the design of a low-cost prosthetic device for shoulder disarticulation. A proper design of the mechanisms has been addressed to obtain a prototype that presents 7 degrees of freedom. Shoulder movement is achieved by means of a spherical parallel manipulator, elbow movement is performed by a six-bar mechanism, and the wrist movement is implemented by a spherical parallel manipulator. A set of dynamic simulations was performed in order to assess the functionality of the design. The prototype was built using 3D printing techniques and implementing low-cost actuators. An experimental evaluation was carried out to characterize this device. The result of this work is a prototype that weighs 1350 g that is able to perform movements related to activities of daily living.