| 摘要 |
PROBLEM TO BE SOLVED: To provide an examination device allowing for recognizing numbers of blood vessels even in positions where two blood-vessels with a different contrast run parallel. SOLUTION: Waveforms for processing a fundus angiogram with two blood vessels are shown in graphs (g) to (p). A graph (a) is an output signal of unidimensional CCD; the graph (a) is processed by a noise rejection using a low pass filter circuit, and is converted into the graph (i) by arithmetic processing for extracting only the angiogram. An output Lp of the low pass circuit is subtracted from an output Ph in an addition circuit, this signal is sent to a circuit for removing unnecessary signal levels; the level of signals to be removed are determined; an unnecessary background for extracting characteristics in the vessel position is removed by saturation; the signal is processed again by the low pass filter and differentiation, and is input into zero cross comparison; an binary signal (l) extracted from a buildup is output into a vessel closeness judgment part for making distinction between one thick and two thin vessels. |
