Patent ID: 6840622
Filing Date: 2005-01-11
Classification: A61B

Abstract:
1. A method for determining the topography for the reaction signals of an eye, by simultaneously measuring the reaction signals that are generated by a plurality of partial surfaces of the retina of an eye by light stimuli and that are produced in the steady state in the case of cyclic excitation, wherein each partial surface is stimulated by an integral number of complete oscillations of the light stimuli in a prescribed time interval for the measurement, and wherein the number of the oscillations in the prescribed time interval for the individual partial surfaces in each case differs by an integral multiple of 1 by virtue of the fact that there is formed in a prescribed time interval for the measurement a clock pulse rate with a specific total number of clock pulses from which an integral number of cycles with one oscillation in each case is counted, and wherein the generation of the oscillations for the partial surfaces is performed in such a way that a mean number of oscillations is formed for a first partial surface by using the cycles generated at the clock pulse rate, for a first group of partial surfaces a first group of oscillations is formed by prolonging the generated cycles at specific and largely constant intervals by individual clock pulses, as a result of which a smaller number of oscillations occurs in the prescribed total number of clock pulses, that for each of the partial surfaces assigned to this group a different interval is used for the prolongation by a clock pulse, and that the number of the clock pulses used for the prolongation is in each case an integral multiple of the number of the clock pulses used for the mean number of oscillations, and for a second group of partial surfaces a second group of oscillations is formed by shortening the generated cycles at specific constant intervals by individual clock pulses, as a result of which a larger number of oscillations occurs in the prescribed total number of clock pulses, that for each of the partial surfaces assigned to this group a different interval is used for the shortening by a clock pulse, and the number of the clock pulses used for the shortening is in each case an integral multiple of the number of the clock pulses used for the mean oscillation, and wherein a plurality of additional oscillations before the time interval for the measurement are provided for reaching the steady state, and at least one additional oscillation after the time interval for the measurement is provided for evaluating the last oscillation, wherein an aggregate signal that is formed from the superimposition of the reaction signals of all the partial surfaces is tapped at the patient and is fed, amplified and filtered, to an analog-to-digital converter that accepts the signal with the same clock pulses used for generating the oscillations, and wherein the reaction signals for the individual partial surfaces are recovered by cyclic summation of the successive portions of the aggregate signal, use being made for the summation of the same cycles as for the oscillations for stimulating the corresponding partial surfaces.