Defect-free optimization of a polycentric prosthetic knee design using an imperialist-inspired optimization method

Abstract EN

Lower limb disability is one of the major problems facing human lives.

To restore the missing functionality and aesthetic features of an amputee's locomotion, finding the optimal design of a human knee prosthesis is crucial.

This paper focuses on the design optimization of a four bar knee mechanism capable of reproducing the complex flexion/extension knee joint motion in the sagittal plane with variable instantaneous centre of rotation positions.

Thus, an optimization approach with appropriate constraints is formulated to consider the degree of compatibility between the instantaneous centre of rotation trajectories of the human reference knee joint and the four bar knee mechanism.

To solve this highly nonlinear optimization problem, an algorithm based on a multiobjective modified imperialist competitive method, where all the constraints are managed with a penalty method, is proposed.

The results obtained by the multiobjective modified imperialist competitive method show that it is possible to obtain a small tracking error.

The obtained results prove the effectiveness of the proposed optimization approach for the optimal synthesis of a four bar knee mechanism compared with that of other literature techniques.