| 摘要 |
<p>PURPOSE:To measure the blood flow velocity of the fundus oculi in real time even if the flow velocity changes according to the pulsation of the heart at the time of measuring the blood flow velocity. CONSTITUTION:The luminous flux from a light source 38 for measurement which emits an He-Ne laser beam is projected to the blood vessel Ev on the fundus oculi Ea and the reflected light from the blood vessel is reflected by a pair of small mirrors 31a, 31b behind a holed mirror 30 and is received by a photomultiplier 40a. The Doppler signals from the photomultiplier 40a are inputted to a phase locked loop circuit of which the self-traveling frequency is approximated from a high-frequency side where the Doppler signals do not exist to multiply the max. blood flow velocity of the blood vessel Ev forming laminar flow by phase synchronization. Further, a suitable input sensitivity and synchronizing range are set in the phase locked loop circuit and the blood flow velocity is measured in real time.</p> |
