コリオリ刺激の力学

I. コリオリ刺激時の半規管出力

抄録

To estimate the turning sensation caused by Coriolis stimulus (cross-coupled rotation), motion of the endolymph in the semicircular canals during the stimulus was deduced by an approach of mechanics, and sensory output from the semicircular canals was estimated. Coordinate systems fixed in space, a horizontally rotating device, subject's head, and 6 individual semicircular canals were defined so that canal motion and turning sensation during Coriolis stimulus were simply presented. Transformations between the coordinate systems were given in matrices. A simple model of the semicircular canal was hypothesized, and an equation of motion of the endolymph in the semicircular canal-fixed coordinate system was formulated. By solving the equation, rotating angle of the endolymph was estimated. Proportional relation between turning sensation and the rotating angle of the endolymph was further hypothesized. It was then shown that the turning sensation derived from each semicircular canal is equivalent to a half of the angular velocity change around an axis perpendicular to the individual canal plane if every semicircular canal contributes equally to the turning sensation in a three-dimensional space. In the following paper, turning sensations derived by the whole semicircular canal system during a single Coriolis stimulus and cyclic Coriolis stimuli are discussed.