温度性眼振検査のコンピュータ計測

Abstract

We have introduced a computer system to control and analyze equilibrium examinations in the clinical routine. An algorithm to analyze caloric responses, the usefulness of this system and parameters to evaluate the responses by computer analysis are reported. Caloric stimulation is given by 24°C cold and 50°C hot air at a 61/min. flow rate for one minute. Nystagmus waves elicited by the calorization are automatically identified, and the amplitude and velocity of nystagmus are calculated by on-line real time process. After all equilibrium examinations of a patient are completed, the caloric responses are computed and the results are printed on an X-Y plotter along with the results of optokinetic nystagmus and rotatory test. The slow phase velocity of each nystagmus are plotted and the values of duration, the number of nystagmus, maximum slow phase velocity and total amplitude in each calorization are indicated on the graph. The percentage of canal paresis (CP) and directional preponderance (DP) of each parameter are also printed on the graph. We can qualitatively observe caloric responses by the graph of the slow phase velocity and quantitatively evaluate disorders of the responses by the indicated values. Computer analysis of caloric nystagmus is very useful to evaluate responses correctly, particularly in cases showing such complicated responses as both CP and DP are combined or those are influenced by spontaneous nystagmus. We concluded that the maximum slow phase velocity is the best parameter to evaluate caloric test in the computer analysis.