Prosthetic hand with a linkage finger mechanism for power grasping applications

The human hand is an exceptionally significant part of the human body which has a very complex biological system with bones, joints, and muscles. Among all hand functions, power grasping plays a crucial role in the activities of daily living. In this research a prosthetic terminal device is designed to assist the power grasping activities of amputees subjected to wrist disarticulation. The designed terminal device contains four identical fingers made of a novel linkage mechanism, which can accomplish flexion and extension. With the intention of verifying the effectiveness of the mechanism, kinematic analysis has been carried out. Furthermore, the motion simulation has demonstrated that the mechanism is capable of generating the appropriate finger movements to accomplish cylindrical and spherical power grasps. In addition, the work envelop of the proposed prosthetic finger has been determined. The 3D printed prototype of the finger was experimentally tested. The experimental results validate the effectiveness of the proposed mechanism to gain the expected motion patterns.