| 摘要 |
PURPOSE:To measure a characteristic parameter by separating an accurate OP wave by applying real time waveform data processing due to a moving averaging method and a differentiation method to the rhythmic small wave superposed on an (a)-wave and a (b)-wave different in delay with respect to light stimulation. CONSTITUTION:An ERG waveform is differentiated to calculate a differential waveform and the peak intervals T1, T2, T3 of the OP wave superposed on the (b)-wave are calculated from the zero cross points of the differential waveform and the arithmetic mean thereof is set to a mean cycle T of the OP wave. ERG waveforms are subjected to moving average on the basis of the mean cycle T and this mean value is subtracted from the original ERG waveform to extract a temporary OP wave component which is, in turn, differentiated to determine the first peak point P and temporary start point A of the OP wave from the zero cross points thereof. The waveform after the A-point is rotated by 180 deg. around the A-point to be extended and subjected to moving mean on the basis of the cycle T to connect the original waveform to the calculated waveform and a waveform wherein the OP wave component is removed is obtained. The A-point is successively moved and a point A<n> at the time when a smooth waveform can be given is set to a start point B and the obtained waveform is subtracted from the original ERG waveform to obtain a waveform only of an OP wave component. |
