abstract |
Process and system for determining the topography of bioelectric response signals of a visual system including a patient's retina, optical nerve or a projection thereof at the level of the central cortex, following visual stimulation through a surface arranged in front of the patient's eye. An image which comprises a plurality of cells is displayed as stimulation, each cell being activated or deactivated according to a corresponding digital time function represented by a cyclical succession of binary m-sequences of duration (T) formed from a plurality of activation symbols (N), each having a duration (Ts), the m-sequences of the various cells being obtained cyclically from a mother m-sequence. The process determines the total bioelectric response of the visual system, the response associated with each cell being determined by the total response of the visual system using a cross-correlation with a suitable translated version of a mother m-sequence. The calculation of the response of each cell is updated at the end of each symbol time (Ts), thereby making it possible to follow the evolution of the calculated response of each cell in real-time, without awaiting the end of an m-sequence. |