Kinematic Simulator of e-Knee Robo that Reproduces Human Knee-Joint Movement

Abstract

Our previously developed e-Knee Robo is a simple structure that can reproduce healthy human knee-joint movements. Since many people suffer from osteoarthritis or ligament injuries, e-Knee Robo must be able to reproduce abnormal knee movements. Reproducing them using e-Knee Robo, e.g., changing the shape of the bones and determining the positions for attaching ligaments to the bones, can be very time consuming. Therefore, it is worth developing a simulator that reproduces e-Knee Robo's movement to address this difficulty. This paper describes the development of a kinematic simulator for e-Knee Robo. To accomplish this, the knee-joint surfaces of the femur and tibia were modeled using approximate polynomial equations. For each flexion angle, 0° to 90°, the remaining five degrees-of-freedom movements were tested. The results showed that the developed simulator can reproduce adductions, lateral tibial displacements, and joint displacements.