Development of an Under-Actuated Robotic Device for Knee Loading Applications

Mechanical stimuli are crucial for the growth, development, and maintenance of articular cartilage and bone. This paper investigates a novel mechanical loading device with position specific loading capability for stimulating articular cartilage and bone. It proposes a design of an under-actuated multi-fingered robotic hand for achieving such a joint loading. The robotic hand has 8-degrees of freedom and is operated by a single motor. Four fingers, each having two phalanges were designed. The fingers are connected through shafts and are operated using a slider crank mechanism. The CAD model was constructed in Creo and then exported to Simmechanics, a toolbox in MATLAB / SIMULINK module where dynamic force analysis was performed. The simulation results validate that the device can produce the necessary magnitude of forces at required frequencies to promote the stimulation of articular cartilage and bone growth.