DEVICE FOR EVALUATION OF EYE FUNDUS BLOOD SUPPLY Russian patent published in 1996 - IPC

FIELD: medicine, particularly, ophthalmology. SUBSTANCE: device has illumination-projection unit, consisted of light source radiating two spectral lines, one of which corresponds to minimum absorption of light by hemoglobin, but other - maximum absorption, ophthalmoscope, light splitter attached to output of ophthalmoscope, first and second light filters installed, accordingly, at first and second output of light splitter, with first filter having pass band corresponding minimum absorption of light by hemoglobin, while pass band of second filter being in accordance with maximum absorption, first and second photodetectors arranged in plane of eye fundus image formed by ophthalmoscope near outputs of first and second light filters, comparator, and control signal shaper; novelty consists in using two auxiliary light sources generating two spectral lines corresponding minimum and maximum light absorption by hemoglobin and installed so that each of them may be inserted in succession to projecting system of illumination-projection unit; besides, two variable resistors and two subtraction units are additionally incorporated into device, herewith outputs of first and second photodetectors are connected to inputs of comparator through first inputs of first and second subtraction units, but outputs of first and second subtraction units are connected to common bus through first and second variable resistors, with sliding contacts of variable resistors being connected, accordingly, to second inputs of second and first subtraction units. EFFECT: improved accuracy of evaluation of eye fundus blood supply. 1 dwg