Development of a 6-DOF robotic test system for studying the biomechanics of total knee replacement

Abstract

A robotic-based joint testing system for studying the biomechanics of Total Knee Arthroplasty (TKA) was developed in this project. The system is composed of a 6 Degree-of-Freedom (DOF) robotic manipulator (Kawasaki UZ150(TM) and a 6-DOF universal force-moment sensor (JR3[TM]). This testing system offers the ability to operate with force and displacement controls and is capable of characterizing the in-vitro kinematics and the in-situ forces in tissue components of the human knee. In a knee test, the femur is rigidly fixed on a pedestal while the tibia is rigidly mounted to the robot arm through the load cell. This robotic system determines the kinematics response of the knee under various external-loading conditions. The kinematics data can then be reproduced on the knee specimen. Upon simulation of knee motion, forces and displacements are evaluated from the load cell and the robot, respectively. Various TKA designs can be tested on the same specimen where the native knee is used as the reference for the evaluation of the biomechanical response of the TKA. The system could be further modified to determine optimal designs of various artificial joint replacements, using normal joint biomechanics as an objective function.