Design of a prosthetic finger for a patient with a partially amputated finger

This study proposed the design of a prosthetic finger that can perform functions, such as motion and gripping, without patients (with amputated fingers) needing an additional actuator. The contributions and contents of this study are as follows: First, the structure of a prosthetic finger, which could be operated by the patient’s own volition without an external actuator, was introduced. Second, the mathematical relationship for effectively designing the proposed structure was explained. In addition, by using this mathematical relationship, the trend of the fingertip trajectory, according to the link length and angle (the design variables) was analyzed. Through this analysis, an optimal design was achieved to determine the link length at which the root mean square error with the target trajectory was minimized. Third, a design method reflecting the finger size and anatomical structure was proposed. Finally, using the fabricated prototype, the proposed design was tested, and the prosthetic finger, having free motion and the ability to grip objects of various sizes, was experimentally verified.