Retinal Prosthesis Dissertation - Student Home Pages

Chapter 1 Introduction/research aim
The approach to be taken for this work is to determine and then decide how to
implement a retinal prosthesis capable of restoring sufficient vision to a person
suffering visual impairment to improve their quality of life. My goal here is not to
implant an actual prosthesis but to evaluate ideas about the way to efficiently
communicate the signals to the prosthesis. The boundaries of my study are to
behaviourally programme in a Virtex 5 FPGA[16] a test image of 1024 pixels and
structurally implement; in terms of VHDL programming, using the Xilinx ISE
platform an image of 16 pixels as proof of concept. The limitation of the structural
implementation is that the output of the FPGA will further require a post processing
interface i.e. the microstimulator or driver portion [17-22] which typically resides on
the retinal implant itself and enables the outputted signals from the FPGA to control
the timing of the charge being delivered to the electrodes of the retinal implant array
[23-30]. Although ten percent of the population suffer from visual impairment; so in
the UK six million people, only ten percent of those suffer from AMD (age related
macular degeneration) [Aside young people can also suffer from this condition] and
RP (retinitis pigmentosa) a family of related diseases to which this study applies.
Although this represents less than one million people in the UK clearly the
European/worldwide market is much bigger. It also bears saying that the gift of sight
is priceless for each person affected to a greater or lesser degree.
1.1 Introductory Literature Review
The following subsections pick out the differing approaches from the relevant
literature and also the commonality of those approaches where this exists.
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