抄録
1) A simple improvement to a clinical turning chair is given.
2) A method of rotatory stimulation of the vestibular receptors has been worked out which allows the measurement of the threshold of ocular nystagmus in humans.
3) The stimulating technique consists of an initial acceleration of short duration followed by a long lasting deceleration without a pause between the two.
4) Nystagmus is recorded electrically during and after the rotation. The nystagmic response appears immediately after the beginning of the rotation and then subsides. After a while a reversed nystagmus (opposite in direction to the preceding nystagmus) appears.
5) Theoretical formula of the cupula-endolymph displacement based on the general theory of the cupular mechanism established by Steinhausen, van Egmond, et al. are given subject to the conditions of stimulus.
6) The threshold of ocular nystagmus during rotatory stimulation can be computed by measurement of parameters such as initial angular velocity, durations of acceleration and deceleration and the time of appearance of the reversed nystagmus.
7) Average values of the threshold (expressed by the angular deviation of the cupula-endolymph system) are:0.84° for clockwise rotation and 0.86° for counterclockwise rotation.
8) The fiducial limits are also given:
0.70°-0.88° and 0.82°-0.90° respectively.
9) The most important advantage of this method is its application to clinical investigations.The method also indicates numerous possibilities for quantitative determination of vestibular dysfunctin in a manner not dissimilar to audiometry in auditory function.
