ESTIMATION OF SACCADIC EYE MOVEMENT MUSCLE FORCES USING SYSTEM IDENTIFICATION TECHNIQUES

Abstract

This chapter presents an investigation that utilizes system identification techniques to estimate muscle forces during horizontal saccadic eye movements. Parameters were estimated using a time domain parameter estimation routine. The large and brief estimated agonist muscle force, however, was not consistent with physiological evidence. This project uses frequency response methods to estimate muscle forces on a 4th order oculomotor plant during saccadic eye movements. System identification techniques were used to estimate the eigenvalues of the oculomotor plant and muscle forces during saccadic eye movements. While the eigenvalues, pulse width, pulse height, and steady state muscle forces appear to be consistent with the physiological data and estimates of other investigators, the estimates of the time constants appear inconsistent with the observations reported by Robinson. One explanation is that the developed muscle force is not a low-pass filtered pulse step but a more complex signal. While the time response indicates an excellent fit between model and data, there appears a more significant lack of fit in the magnitude frequency response. This lack of fit may be indicative of a more complex muscle force signal.