コンピュータ化したENG(Computerized ENG)の試み

Abstract

A new device to observe and record eye movement was developed. This device consisted of two analog amplifiers to record horizontal and vertical eye movements, a small computer (PDP11/34), a laser printer and an X-Y plotter. An analog amplifier was only used to amplify weak signals with a long time constant, i. e. D. C. or longer than 3.0 sec, and with a low pass filter. All other functions of the conventional electronystagmography (ENG)were computerized. Instead of the pen mechanism of ENG, the graphic display, X-Y plotter and laser printer were used to observe and record eye movement. Just sampled eye movements are shown on the graphic display for ten seconds and printed on the X-Y plotter and/or laser printer after disappeared from the graphic display. As eye movement is seen after magnification on the graphic screen, fine nystagmus can be observed without the aid of velocity component in the conventional ENG. The time scale and the magnification of waves can be changed to suite each nystagmus responses. As this system can analyze nystagmus responses such as caloric test, optokinetic nystagmus and rotatory test, the test results are immediately indicated on the output devices after the completion of each examination.Beside the many merits described so far, this system has two big merits:The recorded eye movements and the results of analysis are printed out after being summarized, and can be kept on magnetic discs at a low cost. Therefore we can reduce space to keep the clinical records of many patients. We can purchase this device at a lower cost than the conventional ENG.