Retinal Prosthesis Dissertation - Student Home Pages

List of figures
Figure 1 Layer structure ......................................................................................................................... 13
Figure 2 Eye diagram (image: Wikimedia Commons public domain) ..................................................... 14
Figure 3 Mapping of Image Pixels to Stimulus Electrode Signals .......................................................... 17
Figure 4 fouter = 50(fpacket) ........................................................................................................................ 19
Figure 5 fspike_clock = 5(fouterpulse) ............................................................................................................... 20
Figure 6 fpartial_spike_clock = 4(finnerpulse) ....................................................................................................... 20
Figure 7 replacing the retina .................................................................................................................. 25
Figure 8 pixel by pixel mapping ............................................................................................................. 26
Figure 9 the first neuron model .............................................................................................................. 27
Figure 10 Adaline detail showing the ALC feeding to a bipolar output function. .................................... 30
Figure 11 neuronic detail ....................................................................................................................... 31
Figure 12 (a) shows linear discrimination as opposed to (b), (c) and (d) ............................................... 33
Figure 13 A hyperplane separating two classes/clusters of data. .......................................................... 34
Figure 14 message packet .................................................................................................................... 37
Figure 15 I frame sequencing ................................................................................................................ 40
Figure 16 colour dichotomy ................................................................................................................... 42
Figure 17 Flowchart of MATLAB program of Appendix A ...................................................................... 43
Figure 18 program output ...................................................................................................................... 45
Figure 19 Comparing epi_retinal approaches ........................................................................................ 46
Figure 20 Simulation context diagram (level 0) ...................................................................................... 47
Figure 21 FPGA view of processing ...................................................................................................... 48
Figure 22 AER Delivery ......................................................................................................................... 52
Figure 23 Biological neuron ................................................................................................................... 53
Figure 24 Action Potential ...................................................................................................................... 54
Figure 25 Retinal colour processing (original) ....................................................................................... 56
Figure 26 Four Colour Opponent Theory ............................................................................................... 60
Figure 27 Retinal Structure .................................................................................................................... 63
Figure 28 Receptive field example......................................................................................................... 65
Figure 29 showing fifty pulses/s (representing maximum intensity) and 5 pulses/s
(representing minimum intensity) .................................................................................................. 67
Figure 30 50 pulses/s and 5 pulses/s for one plane of virtual wire of test scene ................................... 70
Figure 31 1024 pixel behavioural test image ......................................................................................... 72
Figure 32 Colour composition ................................................................................................................ 73
Figure 33 sixteen pixel image ................................................................................................................ 74
Figure 34 Biphasic pulse compared to `spike’ ....................................................................................... 76
Figure 35 Correspondence of pixels to colour ....................................................................................... 78
Figure 36; Envisaged System ................................................................................................................ 79
Figure 37 Tae versus fps ........................................................................................................................ 80
Figure 38 forming AER stream .............................................................................................................. 83
Figure 39 Forming AER stream ............................................................................................................. 83
Figure 40 sender program overview ...................................................................................................... 84
Figure 41 Display of AER test image ..................................................................................................... 87
Figure 42 sender chip power analyser screenprint ................................................................................ 88
Figure 43 sender_rtl_16 ......................................................................................................................... 90
Figure 44 upto 1024 image i.e. 32 by 32 ............................................................................................... 92
Figure 45 (1048576) image limit i.e. 1024 by 1024................................................................................ 93
Figure 46 Receiver block diagram ......................................................................................................... 94
Figure 47 receiver power analysis ......................................................................................................... 96
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