1991 Volume 1991 Issue Supplement51 Pages 31-37
Quantitative analysis of pursuit eye movement was performed by means of fast Fourier transform (FFT). Normal subjects were examined with various stimuli to detect changes in parameters. Stimuli consisted of sinusoidal curves of varying amplitudes and frequencies.
The subjects were 5 healthy normal persons.
The analysis was performed using a computer (Masscomp MC5450). Eye movement data were converted to digital signals at a rate of 100 samples/sec., and after smoothing, eye velocity was calculated by the least square method. After the removal of saccade components, only smooth eye movement components were extracted by FFT.
Parameters for analysis were pursuit gain (stimulus velocity / eye velocity) and phase. Pursuit gain decreased with an increase in stimulus frequency, while no significant differences were seen with changes in the magnitude of the stimulus amplitude. In the phase analysis, phase lag was recognized for all stimuli. Phase lag was also strongly influenced by the stimulus frequency rather than by the stimulus amplitude. Based on the relationship between stimulus velocity and pursuit gain, the limit of smooth pursuit eye movement was established at 70 deg/s.
