Biodynamical eye movements models for pupil and eye plant

Abstract

The biodynamic of the eye comprise a widely range of voluntary and involuntary movements. Together these movements perform one of the main processes in the human vision that is to put an image in the retina with the accurate focus. These movements are controlled by the intrinsic and extrinsic eye muscles. Understanding the process of how of each one of this muscles contribute and were altered by other systems in the body is one of the main goals of the bio-medical engineering researchers. Models presented in this work pretend to make an approach in the behavior of two important physiological eye reactions, the pupil response and saccadic eye movements. In the first case a mathematical model was developed to show the effect in pupil diameter caused by blinks, hippus, and sounds stimuli. This response is absolutely involuntary and it is related directly by the sympathetic and parasympathetic nervous system functions. On the other case, for saccadic movements was designed a electronic active model that generate electrical signals according to horizontal eye movements and was intended to emulate the biodynamic rotatory properties of a human eye plant caused by neurologic activation signals on the lateral and medial extrinsic muscles. Properties of the mechanical eye plant, such as viscosity, inertia and elasticity were also included. Some advantages of these models lie in its response and the ease of obtaining continuous records for the dynamics eye response in a signal that features make possible its application in biomedical areas, also including specialists such as Neuro-ophthalmologists, ophthalmologists and optometrist, and even for medical education. © 2013 Springer.