Development of a Low-Cost 3D-Printed Upper Limb Prosthetic Device with Hybrid Actuation for Partial Hand Amputees

Assistive technology plays an important role in rehabilitation. Body-powered tools rely on manual movement of the artificial limb while externally powered machines use actuators to induce mobility and return function. Alternatively, some devices incorporate both systems. In the case of below-the-wrist amputation, availability of such prosthetics is quite limited according to the literature. Our aim was to establish an alternative design for a partial hand prosthetic with both body and external power. A mixed actuation system was conceived. To generate the grasping force required to impel the transitional partial hand prosthetic, three DC motors were used. As a result, a grasping force of 2.8 kgf was possible to achieve at a 600 mA drawn current at 6 V. Furthermore, a locking system and a pretension system were included to enhance device handling. The resulting device came at a calculated cost of 260 euros. The proposed design provides a solution for patients with below the wrist partial hand amputation.