2D Jaw-Movement Simulator (JSN/S1)

Human mastication is performed by coordinated motions of several muscles attached to the jaws. To clarify the functions of these muscles, we have developed a jaw movement simulator (JSN/S1). The simulator consists of a 2DOF mechanism and four muscle actuators, capable of realizing jaw movements in a sagittal plane. The actuator is a cable-tendon driven by DC-servo motor, which is controlled under a compliance control scheme to obtain viscoelastic characteristics of the muscle. In order to simulate life-like clenching motion, we attempted to control the position and force at the incisal point, by incorporating position/force sensors to that point, and employing a neural-network based learning control scheme. Consequently, the trajectory and force at the incisal point were successfully converged into desired value through learning process.