You tend to miss certain points about Prof. Warwick's experiments. For instance what of blind/partially sighted people, they don't have wheel chairs but they do try to lead as active and as normal a lifestyle as other people. It's all very well to add bumps on pavements at crossing point, audible signals for crossing points 'when' of course the button is pressed however they are still limited by what tuition they have been given to deal with their impairment. The use of Radio Frequency equipment can aid them in tracking where they are, coupled with such radio broadcasting devices placed into the high street furnishings and the Blind could be able to venture to places they are unfamiliar with, with less fuss. His testing of implantation was probably his way of investigating by what means such RF devices can be fitted. I mean we all from time to time forget our car keys or mobile phone, but to most of us we have the luxury of being able to deal with it, not so for someone in a strange town, on a strange high street that will not be able to see where it was left or dropped.