Author(s)

O. Terán & E. Suaste

Abstract

The design, development and construction of an electronic active model (EAM) were proposed. The model was based on the reciprocal innervation mechanical model for 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 extraocular muscles. Biodynamic properties of the mechanical eye plant, such as viscosity, inertia and elasticity, were included in the EAM in order to obtain a similar response. Apart from these features, voltage controlled resistors (VCRs) based on MOSFET to keep the nonlinearity of the plant were also included. These active elements, together with passive components, constitute the structure of the extraocular muscles, eyeball and tissues around the eyeball. The activation of agonist-antagonist signals were generated by two voltage controlled sources to reproduce the neurological activity. In this way, applying the appropriate signals to generate saccadic movements was obtained by a voltage signal proportional to the velocity of the eye torque. This signal allows one to obtain information relating to acceleration and position in order to validate the EAM. Due to this capability to emulate saccadic movements, the EAM makes it possible to reproduce involuntary eye movements caused by pathologies such as Horizontal Nystagmus. Finally, some of the EAM’s advantages lie in its response velocity and the ease of obtaining continuous records for the dynamic eyeball response in a signal that features ease of recording and application in biomedical areas, and is particularly relevant to specialists such as Neuro-ophthalmologists, ophthalmologists and optometrist, and even for medical education. Keywords: eye plant, electronic model, saccadic eye movements.

Keywords

eye plant, electronic model, saccadic eye movements.