Optimal synthesis of a planar four-link mechanism used in a hand prosthesis

The optimal synthesis of a planar four-link mechanism is carried out with reference to n positions of the output and coupling bars. The effects of the number of positions in the optimal dimensions of the mechanism are presented. Through a comparative study, we are able to select the number of points and the position of each which best satisfy the performance criteria. The optimal mechanism obtained is of the balance–balance type, with a minimum acceptable angle of transmission and no dead point. This crossed four-link mechanism is used in the development of a hand prosthesis.