A dynamic 3-D model of ocular motion

Eye movement systems are ideal for studying human control of movement, since they are of relatively low dimension and easier to control than other neuromuscular systems. This paper presents a model for the dynamics of 3D eye rotation. The system that is presented incorporates muscle mass, general nonlinear musculotendon dynamics and activation dynamics that couple neural controls that are appropriate for saccadic movements to the muscle mechanics. The approach taken in this paper emphasizes a forward or direct dynamic approach that results in a natural flow of neural-to-muscular-to-movement events while utilizing physiologically realistic models of the musculotendon actuators. Numerical simulations illustrate that the model successfully simulates saccadic movements and accurately depicts eye position, velocity and muscle tension