GB1319774A - Visual prosthetic device - Google Patents

Abstract

1319774 Eye stimulating devices NATIONAL RESEARCH DEVELOPMENT CORP 18 June 1970 [26 June 1969] 32398/69 Heading A5R [Also in Division G4] An implantable visual stimulating device comprises a plurality of electrodes E11-E33 for stimulating the striate cortex of the eye, a matrix of normally closed gates G11-G33 connected one to each electrode, and a plurality of radio receivers RR1-3 and RC1-3 tuned to predetermined frequencies and constituting at least two distinctive sets (RR and RC), each gate being switched to an open state to energise the electrode connected thereto when a group, which is unique for each electrode, of at least two of said receivers from respectively different sets simultaneously receive transmitted control signals. In the illustrated two dimensional matrix a given gate G22, for example, conducts when a column receiver RC2 receives a signal from transmitter TC2 to lower the emitter potential of the transistors Tl of all gates G12-G32 in the column 2 and when simultaneously a row receiver RR2 receives a signal from transmitter TR2 to connect the base of transistor T1 of all the gates G21-G23 of row 2 to earth. To stimulate the eye to "see" a pattern of white spots the row transmitters TR1-3 are energised on a sequential basis and the column transmitters TC1-3 are scanned within each phase of a row scanning action. The row transmitters may be scanned at a predetermined energisation level and the column transmitters energised at variable levels or for variable deviations to compensate for different energisation levels required by different electrodes. Adjacent column receivers and the associated transmitters are tuned to mutually different frequencies which also differ from the frequencies of the row receivers and transmitters. The primary input pattern to the transmitters may be derived, for example, from a T.V. camera tube. The gates and receivers may be encapsulated in silicone rubber. The matrix may have more than two dimensions each with a corresponding set of transmitters and receivers.