VISUAL STIMULATOR

摘要

A visual stimulator for light stimulation of a subject's eyes to obtain electroretinogram, electro-oculogram or visually evoked potential responses. The stimulator comprises a light directing means for directing light from a light source into the subject's eyes, attenuator means for selectably attenuating the light source, photodetector means for producing an output signal representative of the radiant energy directed into the subject's eyes and signal processing means for receiving and processing the output signal to derive therefrom further output signals representative of the radiometric or photometric characteristics of said radiant energy. A light shutter comprising first and second shutter leaves affixed to the shafts of first and second galvanometers is also provided. The shutter leaves are positioned for pivotal movement with the galvanometer shafts to attenuate light passing between the shutter leaves. Attenuation control means is provided for selectably varying current signals applied to the galvanometers to selectably pivot the shutter leaves, thereby selectably varying the attenuation of light passing between the shutter leaves.